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Nov 1986

Volume 4, Issue 6, pp. 2441-3173


First principles investigation of chemisorption of moderately heavy atoms on semiconductor surfaces—bromine on silicon

S. M. Mohapatra, N. Sahoo, K. C. Mishra, B. N. Dev, W. M. Gibson, and T. P. Das

J. Vac. Sci. Technol. A 4, 2441 (1986); http://dx.doi.org/10.1116/1.574088 (6 pages)

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Self‐consistent field Hartree–Fock cluster investigations have been carried out for bromine atoms chemisorbed on Si (111) surface using 5, 14, and 27 atom clusters. For the first two clusters, both all‐electron and pseudopotential procedures have been used and the total energy curves as a function of adatom position have been found to compare very well. The third cluster has been studied by the pseudopotential procedure alone. For the five‐atom cluster which corresponds to the SiH3Br molecule, the Si–Br bond distance and 79Br quadrupole coupling constant (e2qQ) are obtained as 2.20 Å and 355.4 MHz, respectively, in very good agreement with the experimental values from microwave measurements of 2.21 Å and 346 MHz. For the surface chemisorbed system, we have studied the location of the bromine atom, the local density of states (LDOS), the frequencies and amplitudes of the Si–Br vibrations and the 79Br quadrupole coupling constant. The calculated Si–Br bond distance of 2.23 Å agrees very well with two experimental values of (2.22±0.01) and (2.17±0.04) Å available in the literature. For the vibrational amplitude, satisfactory agreement is found with the available result for Br on germanium surface. It is hoped that experimental data will become available in the future to test our predictions for the other properties. In particular, it would be desirable to have UPS data to compare with the interesting trends found in the LDOS curves in going from fluorine to chlorine to bromine and quadrupole interaction data to verify the significant decrease in e2qQ in going from the molecule to the surface‐adsorbed system.
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68.03.Fg Evaporation and condensation of liquids
68.43.Mn Adsorption kinetics
68.43.-h Chemisorption/physisorption: adsorbates on surfaces

Hydrogen isotope sorption and recovery by a nonevaporable getter combined with a chemical compressor material

F. Doni, C. Boffito, and B. Ferrario

J. Vac. Sci. Technol. A 4, 2447 (1986); http://dx.doi.org/10.1116/1.574089 (5 pages) | Cited 2 times

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Due to the spreading use of hydrogen isotopes in many advanced fields of physics such as nuclear fusion, there is an increasing interest in devices able to sorb, store, and release these gases safely and controllably. In some cases there is also the requirement to purify the gas during the same adsorption–desorption process. A way to obtain this is to use a nonevaporable getter, which is able to sorb H2 isotopes reversibly and permanently sorb active gases, combined with a chemical compressor material (usually U). The present investigation refers particularly to a combination of getter materials with chemical compressors based on La–Ni–Al and Zr–Fe–V alloys. The nonevaporable getter sorbs H2 isotopes in the temperature range of 20–400 °C, at low pressures, and in a second stage, on heating, releases these gases at higher pressures allowing sorption by the chemical compressor at room temperature. Subsequent heating (200–400 °C) of the compressor provides a hydrogen isotope source at a substantially constant pressure of around 1 atm. The characteristics of these compressor alloys in terms of isotope equilibrium pressure, physical–chemical properties, and their use at defined pressures and temperatures are discussed, together with anticipated practical operation modes.
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68.03.Fg Evaporation and condensation of liquids
68.43.Mn Adsorption kinetics
28.52.-s Fusion reactors
68.43.-h Chemisorption/physisorption: adsorbates on surfaces

Surface processes leading to carbon contamination of photochemically deposited copper films

F. A. Houle, R. J. Wilson, and T. H. Baum

J. Vac. Sci. Technol. A 4, 2452 (1986); http://dx.doi.org/10.1116/1.574090 (7 pages) | Cited 8 times

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Copper films exhibiting periodic microstructure have been grown by photolytic decomposition of bis‐(1,1,1,5,5,5‐hexafluoropentanedionate) copper (II) [Cu(hfac)2] and its ethanolate using ultraviolet light. The composition of the films has been analyzed by Auger spectroscopy as a function of cell temperature, precursor, mode of illumination (pulsed or continuous), and light intensity at nearly constant wavelength. The results show that the concentration of the principal contaminant of the films, carbon, is a function of cw light intensity. Addition of ethanol in the form of Cu(hfac)2(ethanol) also has a profound effect on carbon incorporation. Although the elements O and F are a large component of the gas phase copper complex, they are essentially absent from the films under all conditions. These data, when combined with high‐resolution analysis of the periodic structures on the films, provide information on surface photochemical and thermal processes likely to be important during film growth. They also allow a general comparison to be made between homogeneous and heterogeneous decomposition of Cu(hfac)2.
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68.55.Nq Composition and phase identification
82.50.-m Photochemistry
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
82.65.+r Surface and interface chemistry; heterogeneous catalysis at surfaces

An x‐ray photoelectron spectroscopy study of poly(methylmethacrylate) and poly(α‐methylstyrene) surfaces irradiated by excimer lasers

M. C. Burrell, Y. S. Liu, and H. S. Cole

J. Vac. Sci. Technol. A 4, 2459 (1986); http://dx.doi.org/10.1116/1.574091 (4 pages) | Cited 4 times

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X‐ray photoelectron spectroscopy (XPS) has been used to study the surface composition of poly(methylmethacrylate) (PMMA) and poly(α‐methylstyrene) (α‐MePS) following excimer laser irradiation at 193 nm. For fluence levels between 50 and 300 mJ/cm2, no surface compositional changes were observed after irradiation of PMMA. However, α‐MePS samples showed a decrease in aromatic character following irradiation, as indicated by the decrease in pi–pi∗ intensity in the C 1s region.
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68.35.Dv Composition, segregation; defects and impurities
81.05.Lg Polymers and plastics; rubber; synthetic and natural fibers; organometallic and organic materials
81.65.-b Surface treatments

A correlation of Auger electron spectroscopy, x‐ray photoelectron spectroscopy, and Rutherford backscattering spectrometry measurements on sputter‐deposited titanium nitride thin films

Brad J. Burrow, Alan E. Morgan, and Russell C. Ellwanger

J. Vac. Sci. Technol. A 4, 2463 (1986); http://dx.doi.org/10.1116/1.574092 (7 pages) | Cited 27 times

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Auger and electron spectroscopy for chemical analysis (ESCA) data of TiNx were analyzed as a function of film composition as established by Rutherford backscattering spectrometry (RBS). The overlap of the N(KVV) and Ti(LMM) Auger transitions necessitated the assessment of two methods previously proposed for the derivative spectra. These results were compared with peak height and peak area measurements (after background subtraction) of the well‐separated N(1s) and Ti(2p) ESCA photoemissions. Neither the Auger nor the ESCA N/Ti intensity ratios scaled linearly with the N/Ti compositional ratios determined by RBS, especially for low nitrogen content. This behavior most likely results from ion‐bombardment‐induced losses of nitrogen in those phases with dissolved nitrogen rather than from an increased satellite emission in the Ti(2p) spectra from the near‐stoichiometric nitride. In terms of precision and analysis speed, the Auger peak‐to‐peak quantification methods are preferred over ESCA quantification. In the near‐stoichiometric phase (N/Ti≊1), RBS analysis shows higher sensitivity to nitrogen compositional changes than either ESCA or Auger.
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82.80.Pv Electron spectroscopy (X-ray photoelectron (XPS), Auger electron spectroscopy (AES), etc.)
68.55.Nq Composition and phase identification
82.80.Ms Mass spectrometry (including SIMS, multiphoton ionization and resonance ionization mass spectrometry, MALDI)

Surface analyses of the CdSe0.65Te0.35/aqueous polysulfide interface in relation to its photoelectrochemical properties

R. Tenne, C. Levy‐Clement, and G. Sawatzky

J. Vac. Sci. Technol. A 4, 2470 (1986); http://dx.doi.org/10.1116/1.574093 (7 pages) | Cited 1 time

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The photocorrosion of n‐Cd(Se,Te) electrodes, in potassium and cesium polysulfide solutions, is investigated by x‐ray photoelectron spectroscopy and Auger electron spectrometry. It is shown that Se and Te are exchanged with sulfur from the solution during photocorrosion, possibly via two separate mechanisms: (a) preferential bleaching of tellurium from the crystal matrix, and (b) uniform photocorrosion of the crystal as a whole. Photocurrent spectrum measurements which are presented suggest that a graded band gap is formed when tellurium is preferentially bleached out of the original Cd(Se,Te) crystal. It is shown that cesium is present on the electrode surface which may explain the negative shift of the flat band potential, i.e., increased open circuit voltage of the photoelectrochemical cell. This suggests that the cesium treatment could be used to increase the open circuit voltage of photovoltaic cells.
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81.65.-b Surface treatments
84.60.Jt Photoelectric conversion
82.65.+r Surface and interface chemistry; heterogeneous catalysis at surfaces
82.47.-a Applied electrochemistry

The influence of substrate temperature on the optical losses of ZnS film

A. A. J. Al‐Douri

J. Vac. Sci. Technol. A 4, 2477 (1986); http://dx.doi.org/10.1116/1.574094 (5 pages) | Cited 1 time

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Loss measurements in waveguide thin films are shown to exhibit a sensitive optical probe of surface and volume losses and thus of film quality. The high accuracy and sensitivity of this device was exploited for assessing the role of substrate temperature on the optical performance of ZnS films. In general, film losses tend to increase with substrate temperature. However, broad optima in losses are observed at 200 and 250 °C. A correlation between film structure and scatter losses as measured by the integrating sphere method with results of losses obtained from waveguide mode technique is discussed. This correlation leads to more reliable interpretation of the influence of substrate temperature on the losses of ZnS film.
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75.20.Ck Nonmetals
42.79.Gn Optical waveguides and couplers
81.40.Tv Optical and dielectric properties related to treatment conditions
77.55.-g Dielectric thin films

Surface morphology of chemical vapor deposition grown Ge on Ge substrates

Herzl Aharoni

J. Vac. Sci. Technol. A 4, 2482 (1986); http://dx.doi.org/10.1116/1.573715 (10 pages) | Cited 3 times

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Geometrically defined Ge structures, projecting out from Ge surfaces deposited by a GeH4–He system on (100) Ge substrates, all oriented in the same direction and having a similar shape, are observed using scanning electron microscopy. They indicate the existence of an epitaxial layer–substrate relationship. Under the same growth conditions, but at short deposition periods, these projections are isolated, but as the growth time increases their lateral dimensions increase, the average distance between them decreases, and coalescence occurs. They are identified as local overgrowth, which yields a rough surface, and their origin is attributed to surface and deposition conditions. Morphometric measurements made by an image analyzer have shown the time dependence of these progressive changes.
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68.35.B- Structure of clean surfaces (and surface reconstruction)
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
68.55.-a Thin film structure and morphology

The determination of amorphous layer thickness in ion implanted silicon using secondary ion mass spectrometry

Howard E. Smith, G. H. Morrison, and D. T. Hodul

J. Vac. Sci. Technol. A 4, 2492 (1986); http://dx.doi.org/10.1116/1.573716 (7 pages)

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Secondary ion mass spectrometry has been used to study boron‐doped Si[100] that was rendered amorphous by the implantation of 75As. Using oxygen bombardment and negative secondary ion detection, all secondary ion species show a shift in ion energy of greater than 2 eV upon sputtering through the amorphous layer and into the underlying crystalline silicon. After regrowth of the same specimens by rapid thermal annealing, the secondary ion energy shift occurs significantly deeper, at approximately the p–n junction. In both specimens, the energy shift was shown to be due to bombardment‐induced specimen charging. Thus, the thickness of the amorphous layer in the as‐implanted specimen can be determined by profiling with a narrow secondary ion energy window. Mechanisms for this effect are discussed.
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68.55.-a Thin film structure and morphology
79.20.Rf Atomic, molecular, and ion beam impact and interactions with surfaces
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
61.80.Jh Ion radiation effects

Properties of a‐Si,Ge:H,F alloys prepared by rf glow discharge in an ultrahigh vacuum reactor

J. Kolodzey, S. Aljishi, R. Schwarz, D. Slobodin, and S. Wagner

J. Vac. Sci. Technol. A 4, 2499 (1986); http://dx.doi.org/10.1116/1.573717 (6 pages) | Cited 12 times

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a‐Si1−xGex@B:H,F alloys with the Ge concentration x ranging from 0 to 1 have been prepared by the rf glow discharge decomposition of SiF4, GeF4, and H2 gas mixtures. An ultrahigh vacuum deposition system has been designed and constructed for the preparation of these alloys. The stainless‐steel deposition chamber has Cu gasket‐sealed flanges, is turbomolecular pumped, and reaches a base pressure below 10−7 Torr (10−5 Pa). This deposition system incorporates a load lock which permits short pump‐down cycles and which may reduce impurity contamination of the films. The system is described in detail. Compositional, structural, optical, and electronic properties of alloy films made with this system are reported.
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81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
75.20.Ck Nonmetals
73.61.Cw Elemental semiconductors
73.61.Ey III-V semiconductors
73.61.Ga II-VI semiconductors
73.61.Jc Amorphous semiconductors; glasses
73.61.Le Other inorganic semiconductors
68.55.Nq Composition and phase identification

Radio frequency‐plasma oxidation of fine‐grained Pb‐alloy films formed by codeposition at 90 K

Masato Wada

J. Vac. Sci. Technol. A 4, 2505 (1986); http://dx.doi.org/10.1116/1.573718 (5 pages)

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Oxidation characteristics of fine‐grained (30–50 nm) Pb‐alloy film formed by the codeposition of Pb, In, and Au onto a liquid‐nitrogen‐cooled substrate (∼90 K) were studied in comparison with conventional film of 200 nm grain size formed by the sequential deposition of Au, Pb, and In at room temperature. The oxidized films were examined by Auger electron spectroscopy as well as x‐ray photoelectron spectroscopy and ellipsometry, and the normal tunneling resistance of Josephson junctions fabricated using the above films as base electrodes was measured. The thermal oxides formed on the fine‐grained and conventional films are identical. Rf‐plasma oxidation with these thermal oxides also present results in oxides of identical structure and thickness. In the absence of the thermal oxides, rf‐plasma oxidation of the fine‐grained film leads to In‐rich oxides of smaller thickness compared to the conventional films. It seems reasonable to attribute these results to the difference in grain sizes, i.e., the smaller‐grained films offer the In more available paths to diffuse through the alloy film. When the thermal oxides are present, rf‐plasma oxidation rate is reduced such that the difference in the diffusion rate of In through the alloy film is not evident and identical oxide structure and thickness are obtained.
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81.05.Bx Metals, semimetals, and alloys
68.55.-a Thin film structure and morphology
85.25.-j Superconducting devices
74.50.+r Tunneling phenomena; Josephson effects

Self‐positioned thin Pb‐alloy base electrode Josephson junction

Kenichi Kuroda and Kenji Sato

J. Vac. Sci. Technol. A 4, 2510 (1986); http://dx.doi.org/10.1116/1.573719 (5 pages)

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A self‐positioned thin (SPOT) Pb‐alloy base electrode Josephson junction is developed. In this junction, a 50‐nm thick Pb‐alloy base electrode is restricted within the junction region on an Nb underlayer using a self‐alignment technique. The grain size reduction and the base electrode area restriction greatly improve thermal cycling stability, where the thermal cycling tests of 4000 proposed junctions (5×5 μm2) showed no failures after 4000 cycles. In addition, the elimination of insulator layer stress on the Pb‐alloy base electrode rectifies the problem of size effect on current density. The Nb underlayers also serve to isolate the Pb‐alloy base electrodes from the resistors.
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85.25.-j Superconducting devices
74.50.+r Tunneling phenomena; Josephson effects
74.78.-w Superconducting films and low-dimensional structures
68.55.-a Thin film structure and morphology

Aluminum alloy ultrahigh vacuum system for molecular beam epitaxy

M. Miyamoto, Y. Sumi, S. Komaki, K. Narushima, and H. Ishimaru

J. Vac. Sci. Technol. A 4, 2515 (1986); http://dx.doi.org/10.1116/1.573720 (5 pages) | Cited 1 time

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As a research project for aluminum alloy molecular beam epitaxy systems, a large aluminum alloy chamber with a special surface finish was constructed. Its outgassing rate and ultimate pressure were measured. The special surface finish was analyzed using Auger electron spectroscopy. The oxide layer on the aluminum alloy was about 40 Å thick. The outgassing rate before baking was measured as 10−11 Torr l/s cm2, and the rate after baking (150 °C, 24 h) was 3×10−13 Torr l/s cm2. This value is approximately one to two orders of magnitude lower than that of a stainless‐steel chamber, such as SUS 304. The ultimate pressure was 7×10−11 Torr when pumped with a turbomolecular pump and an ion pump. With addition of the newly developed titanium sublimation pump, the ultimate pressure was 6×10−12 Torr (6.5×10−12 mbar). This ultimate pressure is very low for a large aluminum alloy vacuum chamber. Ceramic coating of SiO2 using a spark discharge in a silicate solution on aluminum alloy was not corroded by gallium. This ceramic treatment was suitable for an ultrahigh vacuum.
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07.30.Hd Vacuum testing methods; leak detectors
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
68.03.Fg Evaporation and condensation of liquids
68.43.Mn Adsorption kinetics

Data analysis for particle balance studies on the axially symmetric divertor experiment

Y. G. Wang, W. P. Poschenrieder, and G. Venus

J. Vac. Sci. Technol. A 4, 2520 (1986); http://dx.doi.org/10.1116/1.573721 (6 pages) | Cited 1 time

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Throughput of H2 or D2 fueling gas during and after a plasma discharge is a strongly time‐dependent quantity. Various data, such as divertor pressure and integral fueling rate, are used in a computer routine to investigate the particle balance on the axially symmetric divertor experiment (ASDEX). It is seen that the dominant portion of the gas required to fuel the plasma is reversibly pumped by the walls. This is due to the dissociation of molecules and subsequent strong wall adsorption of the resulting atoms. The amount of gas lost to the wall increases with plasma density. After the discharge most of the gas is released depending somewhat on the preconditioning of the walls by previous discharges and the time interval in between discharges.
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52.40.Hf Plasma-material interactions; boundary layer effects
52.55.Fa Tokamaks, spherical tokamaks
52.25.Fi Transport properties
28.52.-s Fusion reactors

A three‐point‐pressure method for measuring the gas‐flow rate through a conducting pipe

Haruo Hirano and Nagamitsu Yoshimura

J. Vac. Sci. Technol. A 4, 2526 (1986); http://dx.doi.org/10.1116/1.573722 (5 pages) | Cited 1 time

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A new method for measuring the gas‐flow rate through an outgassing pipe has been introduced, in which the pressures at three different points in the pipe are measured to calculate the real gas‐flow rate. This method was applied to measuring the flow rate of nitrogen through a pipe. The gas‐flow rates calculated using three pressures were compared with those calculated using two pressures under the same condition. The method based on three pressures gave real rates which were higher than those based on two pressures, especially in lower pressure regions, thus indicating the presence of outgassing.
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47.60.-i Flow phenomena in quasi-one-dimensional systems
47.80.-v Instrumentation and measurement methods in fluid dynamics
07.30.Cy Vacuum pumps

The advantages of vertical turbomolecular vacuum pumps with an upper journal bearing

Leonid Livshits and Scott Richter

J. Vac. Sci. Technol. A 4, 2531 (1986); http://dx.doi.org/10.1116/1.573723 (2 pages)

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Abstract Unavailable
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07.30.Cy Vacuum pumps

An extended core‐hole Hamiltonian for a combined study of electron stimulated desorption and photoemission

J. M. López Sancho, J. Rubio, M. P. López Sancho, and M. C. Refolio

J. Vac. Sci. Technol. A 4, 2533 (1986); http://dx.doi.org/10.1116/1.573724 (4 pages)

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Recent developments (two‐hole states) in electron stimulated desorption (ESD) from adsorption systems involving d bands are incorporated into an extended valence‐hole model Hamiltonian which includes explicitly a short‐range Coulomb interaction between adsorbate and substrate. This allows a combined study of photoemission and ESD from the same model. A novel relaxation effect of the metal surface (different from surface plasmon screening) may have a strong effect on the intra‐adsorbate relaxation due to the valence hole and, therefore, on adsorbate–substrate charge transfer processes.
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68.43.-h Chemisorption/physisorption: adsorbates on surfaces
79.60.Jv Interfaces; heterostructures; nanostructures
73.20.-r Electron states at surfaces and interfaces

TiN high temperature diffusion barrier for copper‐gasketed stainless‐steel flanges

E. L. Garwin, E. W. Hoyt, and A. R. Nyaiesh

J. Vac. Sci. Technol. A 4, 2537 (1986); http://dx.doi.org/10.1116/1.573725 (2 pages)

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Klystrons manufactured at the Stanford Linear Accelerator Center are typically baked at temperatures of 550 °C for times as long as 200 h. During these long bakeouts the copper‐gasketed type 304 stainless steel flange joints (seven in all) diffusion bond so intimately that the flanges can be separated only with a jacking fixture, and copper is left on the sealing surfaces. Removal of this copper necessitates the use of abrasive materials, which can result in contamination of the klystron body and compromise its reuse. We report on the use of 50 and 150 Å TiN thin films as a diffusion barrier between the Cu gasket and the stainless‐steel flange.
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68.35.Fx Diffusion; interface formation
66.30.-h Diffusion in solids
68.60.Wm Other nonelectronic physical properties

Erratum: Summary Abstract: Aluminum deposition on low‐temperature GaAs [J. Vac. Sci. Technol. A 4, 882 (1986)]

M. K. Kelly, Nacira Tache, E. Colavita, G. Margaritondo, and A. Kahn

J. Vac. Sci. Technol. A 4, 2539 (1986); http://dx.doi.org/10.1116/1.573726 (1 page)

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Abstract Unavailable
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81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
68.55.-a Thin film structure and morphology
73.40.Ns Metal-nonmetal contacts
73.30.+y Surface double layers, Schottky barriers, and work functions
99.10.Cd Errata

Evaluation of sputter ion plated CoCrAlY and NiCrAlTi coatings for gas turbines

D. S. Rickerby and M. I. Wood

J. Vac. Sci. Technol. A 4, 2557 (1986); http://dx.doi.org/10.1116/1.573727 (8 pages)

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This paper highlights the potential of a simple dc sputtering process to deposit the complex MCrAlY overlay compositions onto the hot end components of gas turbines. Particular advantages of sputter ion plating technology include good control of coating composition, no need to rotate the components to be coated, and deposition in a clean environment. The effect of peening on coating microstructure and the subsequent oxidation behavior of the coating has been examined for a range of MCrAlY compositions. Peening serves to eliminate leader defects from the surface layers by compaction of the coating and also affects the oxide‐growth mechanisms. The surface roughness of the sputter ion plating coatings, both as deposited and after glass bead peening, increases with that of the substrate and compares favorably with published values for electron beam evaporated coatings. For coatings tested between 1020 °C and room temperature in a heat treated and peened condition, fatigue cracks occurred after 100–150 cycles, while for peened and heat treated coatings, the time to crack initiation was extended to 800 cycles. Results from engine endurance trials are also summarized.
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81.15.Jj Ion and electron beam-assisted deposition; ion plating
81.05.Bx Metals, semimetals, and alloys
81.40.Np Fatigue, corrosion fatigue, embrittlement, cracking, fracture, and failure

Titanium distribution in multilayer oxide scales on oxidized INCOLOY 800H

H. B. Grübmeier, A. Naoumidis, and H. A. Schulze

J. Vac. Sci. Technol. A 4, 2565 (1986); http://dx.doi.org/10.1116/1.573728 (6 pages) | Cited 2 times

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Different samples of INCOLOY 800H were exposed up to 950 °C and 10 000 h to a gas atmosphere simulating exposure to steam reforming methane process gas. The results indicated the predominant role of titanium in the formation of the main reaction products. The influence of titanium could be described by the following modifications of the primary oxide phases: (1) changing the lattice parameters of Cr2O3 by small amounts of Ti, (2) formation of solid solution of the spinels MnCr2O4 and Mn2TiO4, and (3) existence of an additional Ti containing phase of ilmenite type. Furthermore, it was observed that (1) manganese was practically insoluble in the Cr2O3 and (2) after long annealing time manganese was lost.
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81.05.Bx Metals, semimetals, and alloys
82.65.+r Surface and interface chemistry; heterogeneous catalysis at surfaces
68.35.B- Structure of clean surfaces (and surface reconstruction)
81.40.Gh Other heat and thermomechanical treatments

Structure and 700 °C hot corrosion behavior of chromium modified platinum–aluminide coatings

M. Dust, P. Deb, D. H. Boone, and S. Shankar

J. Vac. Sci. Technol. A 4, 2571 (1986); http://dx.doi.org/10.1116/1.573729 (6 pages) | Cited 2 times

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It is well known that the addition of chromium to coatings on nickel‐base superalloys improves the hot corrosion resistance of the coating. Recognizing this advantage, the low‐temperature (700 °C) hot corrosion (LTHC) testing of chromium modified platinum aluminides was initiated in order to determine whether combined additions of Cr and Pt were even more beneficial. The substrates chosen were IN100 and IN738, two commercially used nickel‐base superalloys. It was found that the structure of the chromium modified platinum–aluminide coating was dependent on the sequence of modifying element addition. The optimum coating for LTHC resistance was obtained by the Cr–Pt–Al deposition sequence which resulted in a coating with a continuous PtAl2 layer on the surface backed up with a fairly high level of Cr and Pt.
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81.05.Bx Metals, semimetals, and alloys

The oxidation behavior of some FeCrAlY, FeCrAl, and yttrium ion‐implanted FeCrAl alloys compared and contrasted

J. G. Smeggil and A. J. Shuskus

J. Vac. Sci. Technol. A 4, 2577 (1986); http://dx.doi.org/10.1116/1.573730 (6 pages) | Cited 5 times

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The 1050 °C oxidation behavior of an iron–25 wt. % chromium–4 wt. % aluminum alloy modified by yttrium additions was studied. Yttrium was added to this alloy in the form of (1) a metallic addition; (2) an ion implant; and (3) as yttrium sulfide. In agreement with other investigators, metallic yttrium additions effected thin, essentially flat adherent scales. As compared with the base line alloy without any yttrium, implantation did improve the resistance of the scale to cracking. However, highly convoluted scales resulted with the yttrium implants. When yttrium was added as the sulfide, scales were produced similar to those found when no yttrium was added to the alloy. For the base line alloy without yttrium additions, aluminum oxide protrusions (or pegs) developed at the base of the alumina scales. Despite this, the scales were clearly cracked and poorly adherent. In the yttrium‐containing alloy, indigenous sulfur was present in the form of precipitates associated with yttrium.
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81.05.Bx Metals, semimetals, and alloys

High‐temperature behavior of different coatings in high‐performance gas turbines and in laboratory tests

L. Peichl and G. Johner

J. Vac. Sci. Technol. A 4, 2583 (1986); http://dx.doi.org/10.1116/1.573731 (10 pages) | Cited 1 time

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Turbine blades of advanced engines are often subject to a surface attack caused by oxidation or hot corrosion. Typical features of the different modes of high‐temperature surface attack are presented using results of failure analysis of turbine parts and of laboratory experiments. At very high temperatures, interactions take place between the coatings, which are indispensable in this temperature range, and the base metal. Some examples are described that have been gained from cyclic oxidation tests with a nickel‐base single‐crystal alloy and different types of coatings. The development of a broad diffusion zone and the depletion of β phase of the coatings indicate that interdiffusion plays an important role in determining the coating life. In a particular temperature range platelike phases precipitate in the matrix close to the coating. Kirkendall porosity, which frequently occurs at the coating substrate interface at very high temperatures, can markedly reduce the adhesive strength. The behavior of coated parts under mechanical loading is influenced by the coating–substrate combination. Some examples are shown describing creep and thermal fatigue properties of coated components.
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81.05.Bx Metals, semimetals, and alloys
81.40.Np Fatigue, corrosion fatigue, embrittlement, cracking, fracture, and failure
81.40.Lm Deformation, plasticity, and creep

The development of electrodeposits for high‐temperature oxidation/corrosion resistance

F. J. Honey, E. C. Kedward, and V. Wride

J. Vac. Sci. Technol. A 4, 2593 (1986); http://dx.doi.org/10.1116/1.573732 (5 pages) | Cited 3 times

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Electrodeposited composite coatings (ECC’s) are well established as an economical means of combating wear. By use of a plating barrel of novel design, far greater control of the ECC composition is possible. ECC’s have been produced which, after heat treatment, give alloy coatings of the MCrAlY overlay type (M=Co and/or Ni) suitable for high‐temperature corrosion or oxidation resistance. Other coatings containing internal oxides have also been produced. The coating composition, structure, and properties are dependent on the plating parameters, solution chemistry, powder composition, heat treatment, and coating substrate interactions. Furthermore, the coating composition and its reproducibility are governed by the parameters operative within the barrel in which components are coated. Selected coatings have been tested by isothermal oxidation in cyclic oxidation and on a hot corrosion burner rig and have given superior results compared to similar coatings produced by alternative techniques. Turbine blades are being successfully plated in batch quantities with low reject rates and good reproducibility. Finally, a brief comparison of alternative coating techniques is made from both technical and commercial viewpoints with regard to the coating of gas turbine components.
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81.05.Bx Metals, semimetals, and alloys
81.10.Fq Growth from melts; zone melting and refining

Stabilized zirconia–alumina thin films

C. M. Gilmore, C. Quinn, E. F. Skelton, C. R. Gossett, and S. B. Qadri

J. Vac. Sci. Technol. A 4, 2598 (1986); http://dx.doi.org/10.1116/1.573733 (3 pages) | Cited 2 times

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Thin films of zirconia–alumina of 1 to 2 μm in thickness have been produced by reactive magnetron sputtering. Mixtures from pure Al2O3 to pure ZrO2 were produced. The crystal structures of annealed specimens were determined with x‐ray diffraction and the results indicate that the tetragonal phase of zirconia was stabilized at room temperature with alumina. Chemical analysis of the deposited films was determined with Rutherford backscattering and proton scattering.
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68.60.Dv Thermal stability; thermal effects
68.55.-a Thin film structure and morphology
68.55.Nq Composition and phase identification
81.15.Cd Deposition by sputtering

A study of yttrium‐modified aluminide coatings on IN 738 alloy

David C. Tu, C. C. Lin, S. J. Liao, and J. C. Chou

J. Vac. Sci. Technol. A 4, 2601 (1986); http://dx.doi.org/10.1116/1.573734 (8 pages) | Cited 1 time

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The beneficial effect of yttrium in high temperature protective coatings applied by EB–PVD and vacuum plasma spray against oxidation and hot corrosion has been recognized in many studies. In this study, the feasibility of adding yttrium into aluminide coatings has been successfully demonstrated by the conventional pack cementation process. It was found that yttrium oxide was the only practical inert filler material among the oxides investigated. Yttrium can be added into the aluminide coating either prior to or after the pack aluminizing process. Specimens prepared by the different pack cementation sequences were evaluated at 1000 °C for cyclic oxidation resistance up to 250 cycles. The yttriumized IN 738 and the yttriumized/aluminized IN 738 specimens showed very poor resistance compared to either the uncoated or the straight aluminized IN 738 specimens. Gross internal oxidation was found in the yttriumized/aluminized coating. On the other hand, the aluminized/yttriumized IN 738 showed marginal improvement over the straight aluminized IN 738. The aluminized/yttriumized coating had an yttrium rich outer oxide scale and an aluminum oxide inner scale, while the straight aluminized coating had a chromium rich outer oxide scale and an aluminum oxide inner scale.
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81.05.Bx Metals, semimetals, and alloys
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
81.15.Jj Ion and electron beam-assisted deposition; ion plating
81.20.-n Methods of materials synthesis and materials processing

Thin‐film temperature sensors for gas turbine engines: Problems and prospects

R. C. Budhani, S. Prakash, and R. F. Bunshah

J. Vac. Sci. Technol. A 4, 2609 (1986); http://dx.doi.org/10.1116/1.573735 (9 pages) | Cited 3 times

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The increasing trend towards high‐temperature, fuel efficient jet engines has led to the development of complex cooling schemes for the turbine blades. The measurement of temperature of the blade during operation, which is accomplished in conventional blade design by embedding wire thermocouples in the blade wall, causes serious structural and aerodynamic problems in the case of cooled turbines. In order to meet the requirement of temperature measurement in cooled turbines, it is desirable to develop surface‐mounted thin‐film thermocouples or a resistance thermometer. In the current state of the art of thin‐film thermocouples, the sensing element consists of 2‐μm‐thick Pt and Pt 10% Rh thin‐film elements deposited on the insulating surface of the blades and vanes. The insulator is developed by thermal oxidation of a MCrAlY coating which is deposited on the blade and vane surface in the current state of turbine technology. The understanding of the structural and thermoelectric stability of the sensor elements and of the insulating layer of Al2O3 in the hostile environment of a gas turbine requires an in‐depth study of the metallurgical reactions occurring at the thin‐film Al2O3 and Al2O3–MCrAlY interfaces and of the corrosive reactions on the surface of the metal film. The work presented in this review addresses the problems associated with obtaining highly adherent and insulating Al2O3 on the MCrAlY surfaces, adhesion of the sensor elements, thermoelectric stability of the sensors on contamination, and finally the development of a corrosion protection coating. The desired quality Al2O3 has been grown on NiCoCrAlY‐coated nickel‐based superalloy substrates by a combination of oxidation treatments. The interface‐modified Pt and Pt/Rh films are deposited on the oxide by a dc magnetron sputtering technique. The corrosion protection requirements involve deposition of Si–O–N and Si3N4 graded structures on the sensors by the plasma‐assisted chemical vapor deposition process. Details of the electrical and metallurgical characteristics of the device at each stage of the coating/film growth have been analyzed by a number of surface sensitive and bulk analytical techniques.
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07.20.Dt Thermometers
81.05.Bx Metals, semimetals, and alloys
68.60.Bs Mechanical and acoustical properties

Thin film thermocouples for internal combustion engines

Kenneth G. Kreider

J. Vac. Sci. Technol. A 4, 2618 (1986); http://dx.doi.org/10.1116/1.573736 (6 pages) | Cited 6 times

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The feasibility of fabricating thin film thermocouples on internal combustion engine hardware was investigated. The goal was to find a procedure that would be useful for the measurement of the surface metal temperature of valves, valve seats, combustion chamber surfaces, cylinder walls, and piston heads during engine operation. The approach pursued was to coat the engine hardware material with an aluminum‐containing, oxidation‐resistant ferrous alloy (FeCrAlY) which forms a thermal oxide layer with good electrical resistance. This thermal oxide was coated with a thin layer of reactively sputtered aluminum oxide and sputtered thin film type S thermocouple legs of platinum and platinum plus rhodium. This project was used to investigate the materials problems related to obtaining good adhesion in the metal/metal–oxide/oxide/metal laminate and the electrical insulating properties of the oxide. Thermal oxidation, reactive sputtering of Al2O3, and platinum alloy sputtering were investigated using optical microscopy, x‐ray photoemission spectroscopy (XPS), laminar adhesion testing, and the evaluation of high temperature electrical properties. A successful method for fabricating thin film thermocouples on internal combustion engine materials was developed. Adherent, electrically insulating aluminum oxide with a type S thermocouple was produced on a 10 cm long stainless steel bar. The fabrication techniques and results of tests run on that bar as well as on numerous small test coupons are presented.
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07.20.Dt Thermometers
89.40.-a Transportation

Coatings for performance retention

R. V. Hillery

J. Vac. Sci. Technol. A 4, 2624 (1986); http://dx.doi.org/10.1116/1.573693 (5 pages)

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Performance and performance retention are becoming increasingly important in today’s gas turbine engines. The military aircraft engine operator wants the flexibility and flight envelope that increased performance will give, and the commercial user—aircraft, utility generation, or pumper—demands the long term fuel economy that improved performance retention will provide. Materials advances have provided the intrinsic strength and temperature increases to push the capability of today’s engines, and coatings have been an integral part of that advancement. Specifically, in the performance retention area, coatings and seal systems have become increasingly important in both compressor and turbine components. It is the intent of this overview paper to present a brief review of the coating systems presently in use and in development and to consider areas in which the technology might be heading.
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89.40.-a Transportation
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
68.55.-a Thin film structure and morphology

A new chromium carbide‐based tribological coating for use to 900 °C with particular reference to the Stirling engine

Harold E. Sliney

J. Vac. Sci. Technol. A 4, 2629 (1986); http://dx.doi.org/10.1116/1.573694 (4 pages)

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A new chromium carbide‐based coating (PS 200) is described. This coating is shown to have good friction and wear properties over a wide temperature range. A nickel alloy‐bonded chromium carbide coating was used as a baseline material for comparison with experimental formulated coatings. Coatings were plasma sprayed onto metal disks, then diamond ground to a thickness of 0.025 cm. Friction and wear were determined using a pin on disk tribometer at temperatures from 25 to 900 °C in hydrogen, helium, and air. Pin materials included several metallic alloys and silicon carbide. It was found that appropriate additions of metallic silver and of barium fluoride/calcium fluoride eutectic to the baseline carbide composition significantly reduced friction coefficients while preserving, and in some cases, even enhancing wear resistance. The results of this study demonstrate that PS 200 is a promising coating composition to consider for high‐temperature aerospace and advanced heat engine applications. The excellent results in hydrogen make this coating of particular interest for use in the Stirling engine.
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62.20.Qp Friction, tribology, and hardness
81.40.Pq Friction, lubrication, and wear

Properties of Co+Cr2O3: A wear protective dispersion coating for use at high temperatures

M. Thoma

J. Vac. Sci. Technol. A 4, 2633 (1986); http://dx.doi.org/10.1116/1.573695 (5 pages)

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Co+Cr2O3 is a composite coating of a cobalt matrix with 25 vol % Cr2O3 embedded in it. The mechanical properties of this coating are discussed. The main attribute is the excellent wear resistance of the coating, especially in the temperature range 300–700 °C, owing to the formation of a protective Co3O4 glaze layer. Reciprocating wear was reduced by plating both parts of a pairing, but plating only one part of the pairing reduced the wear of the uncoated part to a similar extent, irrespective of the alloy used. In the temperature range 300–700 °C the wear of both the Co+Cr2O3 coating and the uncoated alloy was reduced to a minimum by the formation of the glaze layer on the Co+Cr2O3 coating. The glaze prevented metal to metal contact and changed the wear mechanism. In the temperature range of optimum wear protection there was also a beneficial effect on the fatigue properties. The high‐cycle fatigue of Co+Cr2O3‐coated Waspaloy was not influenced either when heat treated previously or by use at these temperatures. Low‐cycle fatigue loss of Waspaloy was decreased by a 600 °C preheat treatment. Fretting fatigue of Ti–6Al–4V was increased when coated with Co+Cr2O3 and used at 350 °C.
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62.20.Qp Friction, tribology, and hardness
81.40.Pq Friction, lubrication, and wear
62.20.M- Structural failure of materials
81.40.Np Fatigue, corrosion fatigue, embrittlement, cracking, fracture, and failure

Characterization of coating processes and coatings for steam turbine blades

J. Qureshi, A. Levy, and B. Wang

J. Vac. Sci. Technol. A 4, 2638 (1986); http://dx.doi.org/10.1116/1.573696 (10 pages)

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The exfoliated scale from boiler tubing results in hard particles that erode steam turbine components, particularly stationary and rotating blading. To select an erosion resistant protective coating for steam turbine blades, six promising coating processes comprising ten different coatings were selected for evaluation by erosion testing, metallography, and mechanical tests of coated blade materials. This paper describes the results of the erosion tests and metallographical studies and discusses how erosion resistance is related to coating morphology.
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81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
81.05.Bx Metals, semimetals, and alloys
68.55.-a Thin film structure and morphology
89.30.-g Fossil fuels and nuclear power

Calculations and experimental study of the thermally affected layer caused by friction

L. Rozeanu and D. Pnueli

J. Vac. Sci. Technol. A 4, 2648 (1986); http://dx.doi.org/10.1116/1.573697 (4 pages)

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The concept of a thermally affected layer (TAL) is introduced and used to analyze the temperature field which develops in a coating layer. The analysis is done for both one‐pass surface interaction and for cyclic‐pass interactions. It is shown that for coating materials with low thermal diffusivities the coating thickness must not exceed the TAL thickness. Conditions which thin coatings can withstand may become disastrous for thicker coatings. The results are substantiated by experimental example of a coating of a barrel of a rifle.
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68.60.Bs Mechanical and acoustical properties
81.40.Pq Friction, lubrication, and wear
62.20.Qp Friction, tribology, and hardness

Dip process thermal barrier coatings for gas turbines

Ibrahim M. Allam and David J. Rowcliffe

J. Vac. Sci. Technol. A 4, 2652 (1986); http://dx.doi.org/10.1116/1.573698 (4 pages)

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A new concept to apply zirconia‐based thermal barrier coatings on cobalt base alloys has been developed. Contrary to plasma spraying or electron beam vaporization, the new process produces a dense and highly adherent zirconia coating that resists thermal cycling and penetration by corrosive molten salts. The new method is based on thermally growing a ZrO2‐based layer from a Zr‐rich alloy, predeposited on a Y‐rich substrate by hot dipping. The coating consists of an outer ZrO2/Y2O3 layer and an inner oxide–metal composite layer next to the substrate surface. The outer oxide layer acts as a thermal barrier, while the inner layer acts as a graded seal that improves the adhesion of the coating to the substrate. Thermal cycling experiments showed that the coating has a good resistance to spallation between room temperature and 1100 °C.
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81.15.Lm Liquid phase epitaxy; deposition from liquid phases (melts, solutions, and surface layers on liquids)
81.65.-b Surface treatments
81.40.-z Treatment of materials and its effects on microstructure, nanostructure, and properties

Ionization assisted physical vapor deposition of zirconia thermal barrier coatings

K. S. Fancey and A. Matthews

J. Vac. Sci. Technol. A 4, 2656 (1986); http://dx.doi.org/10.1116/1.573699 (5 pages) | Cited 4 times

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Yttria stabilized zirconia has been deposited by electron beam physical vapor deposition under a range of process conditions. The influence of rf plasma assistance, pressure, surface finish, and source to substrate distance on structure, phase, uniformity, and adhesion has been studied. Coatings were found to be predominantly cubic; their texture could be modified by plasma assistance. Also plasma assistance was found to improve adhesion, permit control of coating structure and densification, and provide the possibility to increase pressures, to improve coating thickness uniformity without loss of structure control. Excellent adhesion was obtained even on polished substrates at low temperatures (<400 °C), which when coupled with the fact that the coating tends to replicate the original surface finish, suggests that good aerodynamic efficiencies and performance should be achieved with thermal barrier coatings produced by this method.
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81.15.Jj Ion and electron beam-assisted deposition; ion plating
68.55.-a Thin film structure and morphology
68.60.Dv Thermal stability; thermal effects
68.35.Gy Mechanical properties; surface strains

Material selection for hard coatings

H. Holleck

J. Vac. Sci. Technol. A 4, 2661 (1986); http://dx.doi.org/10.1116/1.573700 (9 pages) | Cited 107 times

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Multicomponent refractory material systems can provide opportunities for specific materials for wear resistant coatings. The multitude of potential hard coating materials can be subdivided into three groups according to variations in chemical bonding character of the compounds. Many fundamental relations between the position of coating material components in the Periodic Table of the elements and the properties can be used to optimize these material selections. However, restrictions exist because of increasing hardness and strength which primarily decrease toughness and adherence. Multicomponent boride, carbide, nitride, and oxide systems are discussed in view of their potential as coating materials. Additional options for materials selection and optimization arise from the possibility of adjusting specific microstructures in the layers, especially in multilayer and multiphase coatings.
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68.60.Bs Mechanical and acoustical properties
62.20.Qp Friction, tribology, and hardness

The color of TiN and HfN: Aging effects

A. J. Perry

J. Vac. Sci. Technol. A 4, 2670 (1986); http://dx.doi.org/10.1116/1.573701 (4 pages) | Cited 4 times

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The color of TiN films made by plasma enhanced physical vapor deposition (PVD) methods is found to age during storage; this can be accentuated by tempering. A contraction towards the equilibrium value of the pre‐expanded lattice is thought to be responsible for the changes. This is in general accord with a previously presented model. Similar effects are found in HfN films. When studying highly reflecting films the effect of changing measuring geometry from the so‐called d/8 to the d/0 configuration significantly affects the color data.
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81.40.Tv Optical and dielectric properties related to treatment conditions
75.20.Ck Nonmetals

The reflectance and color of titanium nitride

A. J. Perry, M. Georgson, and C. G. Ribbing

J. Vac. Sci. Technol. A 4, 2674 (1986); http://dx.doi.org/10.1116/1.573702 (4 pages) | Cited 3 times

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It is shown that lattice expansion at constant composition can affect the location and slope of the reflectance curve of TiN films in a complex way comparable to the effect of substoichiometry or carbon substitution. Lattice expansion first shifts the reflectance shoulder to lower photon energies, causing the color (chroma) to lighten, and then to higher energies leading to a red cast. Tempering reduces the extremes but leaves a range of color where films made at lower deposition rates are more intensely yellow. The effects are discussed in terms of a simple ionic model and considering lattice defects.
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75.20.Ck Nonmetals
68.55.Nq Composition and phase identification
81.40.Tv Optical and dielectric properties related to treatment conditions
68.55.-a Thin film structure and morphology

Summary Abstract: Hard composite coatings of TiN with C or BN

J. Machet, C. Lory, C. Weissmantel, D. Roth, and E. Siegel

J. Vac. Sci. Technol. A 4, 2678 (1986); http://dx.doi.org/10.1116/1.573703 (2 pages)

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Abstract Unavailable
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62.20.Qp Friction, tribology, and hardness
81.05.Bx Metals, semimetals, and alloys
68.60.Bs Mechanical and acoustical properties
68.35.Gy Mechanical properties; surface strains

Summary Abstract: The use of intermediate layers to improve the adherence of diamondlike carbon films on ZnS and ZnSe

Michael J. Mirtich, Dan Nir, Diane Swec, and Bruce Banks

J. Vac. Sci. Technol. A 4, 2680 (1986); http://dx.doi.org/10.1116/1.573704 (2 pages) | Cited 2 times

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Abstract Unavailable
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62.20.Qp Friction, tribology, and hardness
68.35.Gy Mechanical properties; surface strains

A transmission electron microscopy study on Ti–N films deposited by ion plating

L. S. Wen, X. Jiang, and C. Y. Si

J. Vac. Sci. Technol. A 4, 2682 (1986); http://dx.doi.org/10.1116/1.573705 (4 pages) | Cited 1 time

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The microstructure and interface structure of Ti–N coating deposited by hollow cathode discharge ion plating were investigated with transmission electron microscopy and other methods of microanalysis. A layered structure of the coating was observed, consisting of substrate–FeTi–Ti–Ti2N–TiN. The transition layers FeTi and Ti2N were identified with microbeam electron diffraction. It was also shown that there was a microcrystalline region at the substrate surface. Preferential orientation has been observed and correlated with deposition parameters. The orientation relationships between different layers have been determined. The formation mechanism of transition layers was discussed.
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68.55.-a Thin film structure and morphology
68.35.B- Structure of clean surfaces (and surface reconstruction)
81.15.Jj Ion and electron beam-assisted deposition; ion plating
68.65.-k Low-dimensional, mesoscopic, nanoscale and other related systems: structure and nonelectronic properties

Turning performance of reactively ion plated Ti–N coatings

J. M. Molarius, A. S. Korhonen, H. Kankaanpää, and M. S. Sulonen

J. Vac. Sci. Technol. A 4, 2686 (1986); http://dx.doi.org/10.1116/1.573706 (5 pages) | Cited 1 time

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Ti–N coatings containing from 29 to 53 at. % nitrogen were deposited on high‐speed steel inserts by triode ion plating. The cutting performance of the inserts was compared in a standard turning test and distinct differences were observed between the individual coatings. No direct relation between the thickness and cutting performance was found although some of the thinnest coatings wore out more rapidly and in general scatter was increased due to thickness variations. The cutting performance of the coatings was found to improve with increasing nitrogen content towards stoichiometric TiN. The results indicate that by properly selecting the deposition parameters, coatings having good cutting performance can be prepared in a wide range of compositions extending from about 40 to 50 at. % nitrogen.
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81.40.Pq Friction, lubrication, and wear
62.20.Qp Friction, tribology, and hardness
81.15.Jj Ion and electron beam-assisted deposition; ion plating
68.55.Nq Composition and phase identification

Electrochemically measured porosity of magnetron sputtered TiN films deposited at various substrate orientations

H. Freller and H. P. Lorenz

J. Vac. Sci. Technol. A 4, 2691 (1986); http://dx.doi.org/10.1116/1.573707 (4 pages) | Cited 1 time

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TiN layers were deposited by magnetron sputtering on polished stainless steel substrates, the position of which was changed in steps from parallel to perpendicular relative to the target surface. Substrate target distance was varied between 25 and 50 mm. Bias current density and substrate temperature at the beginning of deposition were also varied. The porosity of the films deposited under these circumstances was measured by an electrochemical method. The double layer capacity electrolyte/TiN film is a measure of the porosity and the true surface area of the deposited film. Dense films were deposited in all substrate positions when the starting temperature was around 300 °C and the bias current densities were above 2 mA/cm2. With bias current densities below 1 mA/cm2 or no bias and a position of the coated plane perpendicular to the target surface, the true surface of the film is enlarged to 500 times that of the geometrical area of the substrate used. The structural changes responsible for the increase in the porosity are shown in scanning electron microscope (SEM) micrographs.
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68.55.-a Thin film structure and morphology

On structure and properties of sputtered Ti and Al based hard compound films

O. Knotek, M. Böhmer, and T. Leyendecker

J. Vac. Sci. Technol. A 4, 2695 (1986); http://dx.doi.org/10.1116/1.573708 (6 pages) | Cited 39 times

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After investigating basic correlations between process and film characteristics in previous works new multicomponent hard coatings, on the basis of Ti–Al and Ti–Zr, have been deposited by magnetron sputtering. These ternary and quaternary nitrides are crystallizing in a face centered cubic TiN lattice with reduced or enlarged lattice parameters depending on the amount and the radius of foreign atoms. Improved wear behavior compared to chemical vapor deposition (CVD) TiN coatings has been stated with (Ti,Al)N, (Ti,Zr)N, and (Ti,Al,V)N coatings. According to these results the development of the coating material itself will be of major interest in the future.
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68.55.-a Thin film structure and morphology
68.60.Bs Mechanical and acoustical properties
62.20.Qp Friction, tribology, and hardness
68.35.Gy Mechanical properties; surface strains

Morphology and properties of sputtered (Ti,Al)N layers on high speed steel substrates as a function of deposition temperature and sputtering atmosphere

Hermann A. Jehn, Siegfried Hofmann, Vera‐Ellen Rückborn, and Wolf‐Dieter Münz

J. Vac. Sci. Technol. A 4, 2701 (1986); http://dx.doi.org/10.1116/1.573709 (5 pages) | Cited 19 times

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(Ti,Al)N layers were prepared by reactive dc and radio‐frequency (rf) magnetron sputtering onto polished flat high speed steel (HSS) surfaces. The rectangular samples were mounted on a special sample holder providing a temperature gradient in the range of 500 °C to room temperature along the length of the sample. The (Ti,Al)N layers were deposited at various N2 and Ar pressures. The target was a Ti–50 at. % Al alloy. The film morphology and composition was observed by scanning electron microscopy (SEM) and Auger electron spectroscopy (AES), respectively, and correlated to mechanical properties like hardness and critical load (scratch test). The results are discussed with the respect of the sputtering conditions.
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68.55.-a Thin film structure and morphology
68.55.Nq Composition and phase identification
68.60.Bs Mechanical and acoustical properties
81.15.Cd Deposition by sputtering

Summary Abstract: Chemical vapor deposition of titanium oxides

Eva Fredriksson and Jan Otto Carlsson

J. Vac. Sci. Technol. A 4, 2706 (1986); http://dx.doi.org/10.1116/1.573710 (1 page)

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Abstract Unavailable
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81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)

Composition, structure, and wear resistance of TiAlOC coatings deposited by chemical vapor deposition

Alfred S. Gates

J. Vac. Sci. Technol. A 4, 2707 (1986); http://dx.doi.org/10.1116/1.573711 (6 pages)

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The deposition of TiwAlxOyCz (TiAlOC) coatings onto cemented tungsten carbide cutting tool inserts by chemical vapor deposition is reported. The TiAlOC coatings are shown to exist in three phase regions: a single‐phase TiAlOC solid solution, a mixture of TiAlOC solid solution and α‐Al2O3, and a mixture of TiC and α‐Al2O3. The wear resistance of coatings from each phase region versus standard commercial coatings is reported.
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68.55.Nq Composition and phase identification
68.55.-a Thin film structure and morphology
68.60.Bs Mechanical and acoustical properties
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)

The role of interface development during chemical vapor deposition in the performance of TiC‐coated cemented carbide cutting tools

D. G. Bhat, T. Cho, and P. F. Woerner

J. Vac. Sci. Technol. A 4, 2713 (1986); http://dx.doi.org/10.1116/1.573712 (4 pages) | Cited 1 time

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The effect of interaction between the furnace atmosphere and the surface of cemented carbide substrate on the properties and performance of TiC coated cutting tools is described. It is shown that a highly decarburizing atmosphere during chemical vapor deposition (CVD) results in the formation of M12C eta phase and tungsten, and considerable diffusion of cobalt into the TiC film. This type of coating is shown to have a poor spalling resistance. On the other hand, a nondecarburizing atmosphere is shown to prevent the formation of tungsten, and diffusion of cobalt into the coating. Also, both M6C and M12C eta phases are found to exist under these conditions. The relative increase in the amount of M6C as compared to M12C is shown to improve the spalling resistance of TiC coating.
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68.35.Fx Diffusion; interface formation
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
81.40.Pq Friction, lubrication, and wear
82.65.+r Surface and interface chemistry; heterogeneous catalysis at surfaces

Titanium aluminum nitride films: A new alternative to TiN coatings

Wolf‐Dieter Münz

J. Vac. Sci. Technol. A 4, 2717 (1986); http://dx.doi.org/10.1116/1.573713 (9 pages) | Cited 74 times

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TiAl films have been produced in various compositions by using the sputter ion plating process. Films sputtered reactively from a target with the composition of TiAl 50:50 at. % have been deposited with a composition of 27.5 at. % Ti, 28.9 at. % Al, and 43.6 at. % N. The crystal structure found was that of sodium chloride with a lattice parameter of 4.20 Å; the microhardness such films was found to be HV 2100–2300. The incorporation of Al into the nitride films improves the oxidation resistance as well as the cutting performances of TiAlN coated drills. TiN films start to oxidize at a temperature level of 550 °C, whereas TiAl coatings react with hot air at a temperature of 800 °C severely. TiAlN coated drills have been tested with two different steels and performed better by a factor >2 compared with TiN coated drills.
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81.15.Cd Deposition by sputtering
81.15.Jj Ion and electron beam-assisted deposition; ion plating
81.05.Bx Metals, semimetals, and alloys
68.55.-a Thin film structure and morphology

Deposition of TiN and Ti(O,C,N) hard coatings by a plasma assisted chemical vapor deposition process

P. Mayr and H.‐R. Stock

J. Vac. Sci. Technol. A 4, 2726 (1986); http://dx.doi.org/10.1116/1.573714 (5 pages) | Cited 7 times

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Using conventional plasma nitriding equipment with a dc power supply, TiN coatings have been deposited from TiCl4, H2, N2, and Ar onto tool steel substrates at temperatures about 500 °C. Coatings of the type Ti(O,C,N) have also been deposited using an organic titanium compound instead of TiCl4. The advantage of this compound is the absence of any chlorine products in the deposited layers.
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81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)

Problems encountered with the introduction of ion plating to large‐scale coating of tools

J. Vogel and E. Bergmann

J. Vac. Sci. Technol. A 4, 2731 (1986); http://dx.doi.org/10.1116/1.573671 (9 pages) | Cited 2 times

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Performance improvements to cutting tools through the use of ion plated coatings are discussed as they relate to the quality of tools used, the specific geometry, and the material type of tool to be coated, as well as variations inherent in the coating process. Current state of the art for mass producing coated tools and the difficulties in quality assurance of tools having different geometries and end purposes is reviewed. Numerous examples are given showing the important aspects of tool condition on tool performance, such as surface roughness, presence of burrs, oxide layers, internal segregation, and heat treatment residues. Extensive data on coated tool life, types of failure, and performance as well as the range of tool material types presently considered suitable for coating are given.
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81.15.Jj Ion and electron beam-assisted deposition; ion plating
81.40.Pq Friction, lubrication, and wear
68.35.Gy Mechanical properties; surface strains
68.35.Fx Diffusion; interface formation

Advances in the electrospark deposition coating process

Roger N. Johnson and G. L. Sheldon

J. Vac. Sci. Technol. A 4, 2740 (1986); http://dx.doi.org/10.1116/1.573672 (7 pages)

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Electrospark deposition (ESD) is a pulsed‐arc microwelding process using short‐duration, high‐current electrical pulses to deposit an electrode material on a metallic substrate. It is one of the few methods available by which a fused, metallurgically bonded coating can be applied with such a low total heat input that the bulk substrate material remains at or near ambient temperatures. The short duration of the electrical pulse allows an extremely rapid solidification of the deposited material and results in an exceptionally fine‐grained, homogeneous coating that approaches (and with some materials, actually is) an amorphous structure. This structure is believed to contribute to the good tribological and corrosion performance observed for hardsurfacing materials used in the demanding environments of high temperatures, liquid metals, and neutron irradiation. A brief historical review of the process is provided, followed by descriptions of the present state of the art and of the performance and applications of electrospark deposition coating in liquid–metal‐cooled nuclear reactors.
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81.15.Jj Ion and electron beam-assisted deposition; ion plating
28.50.-k Fission reactor types
81.05.Bx Metals, semimetals, and alloys
81.40.Pq Friction, lubrication, and wear

The role of hard coatings in carbide milling tools

G. J. Wolfe, C. J. Petrosky, and D. T. Quinto

J. Vac. Sci. Technol. A 4, 2747 (1986); http://dx.doi.org/10.1116/1.573673 (8 pages) | Cited 5 times

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The role of hard coatings in prolonging the life of cemented carbide tools is now well‐documented for continuous turning applications. In contrast, relatively few studies have elucidated the effect of such coatings in milling, where both mechanical and thermal cyclic loading impose special requirements on the tool cutting edge. This investigation describes the wear mechanisms observed in coated carbide milling tools which have been the object of recent commercial tool development. Coated carbide tools (by CVD and PVD) of varying cutting edge geometry, substrate, and coating composition were subjected to fly‐cutter milling tests under a nominal range of cutting conditions. Examination of the used cutting edges under optical and electron microscopy showed both thermal‐fatigue‐induced vertical cracks, perpendicular to the cutting edge, as well as lateral cracks parallel to the edge which result from mechanical cyclic stresses. The wear patterns and the sequential progression of these cracks were characterized on the used tools. It is noted that the coatings tend to inhibit crack propagation rather than reduce crack initiation and serve to delay the onset of typical failure mechanisms found in uncoated tools. The fracture toughness of the cutting edge is more critical in milling than in turning applications. A discussion is given on matching the requirements of edge geometry, material properties of the substrate, and the hard coating to optimize the performance of the coated carbide milling insert.
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62.20.Qp Friction, tribology, and hardness
81.40.Pq Friction, lubrication, and wear
68.60.Bs Mechanical and acoustical properties
68.35.Gy Mechanical properties; surface strains

TiN‐coated high‐speed steel cutting tools

H. Randhawa

J. Vac. Sci. Technol. A 4, 2755 (1986); http://dx.doi.org/10.1116/1.573674 (4 pages) | Cited 3 times

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TiN‐coated cutting tools have gained a wide acceptance in the marketplace over the last few years. This has largely been due to the increased productivity, short machining times, and increased tool life benefits obtained using coated cutting tools. However, the successful coating of tools imposes requirements both in terms of coating processes and/or tool design and substrate materials. This prerequisite of optimizing tool designs, metallurgy, and surface finish to obtain optimum tool benefits when coated can only be achieved by close cooperation between manufacturing operations. This presentation addresses the issues of coatings, tool design, metallurgy, and surface finish quality to yield superior coated cutting tools.
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62.20.Qp Friction, tribology, and hardness
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
68.35.-p Solid surfaces and solid-solid interfaces: structure and energetics

Spalling resistance of physical vapor deposited and chemical vapor deposited TiN coated carbide indexable inserts in a short duration milling test

D. J. Rich and P. F. Woerner

J. Vac. Sci. Technol. A 4, 2759 (1986); http://dx.doi.org/10.1116/1.573675 (4 pages) | Cited 3 times

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Test results are reported from a short duration milling test which is designed to compare the relative resistance to spalling of coated carbide inserts. Carbide inserts coated with TiN by four different commercial physical vapor deposition processes showed consistently lower resistance to spalling than identical inserts coated by a chemical vapor deposition process. This difference in resistance to spalling increased as the coating thickness increased from 2 to 5 μ.
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81.40.Pq Friction, lubrication, and wear
62.20.Qp Friction, tribology, and hardness
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy

Comparison of wear characteristics and properties of TiN‐coated gear cutting hobs

E. Niemi, A. S. Korhonen, E. Harju, and V. Kauppinen

J. Vac. Sci. Technol. A 4, 2763 (1986); http://dx.doi.org/10.1116/1.573676 (5 pages) | Cited 2 times

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Two types of TiN‐coated gear cutting hobs were compared in the hobbing of case hardening steel under production conditions. The coating reduced the wear of the hobs significantly, even though 25% and 50% increased cutting speeds as compared to the uncoated hobs were used. The performance of the two types of TiN coatings denoted by A and B differed markedly. The coating B lasted generally from 1.5 to 2 times longer than A. Mechanical testing of hardness and adhesion by a scratch test gave, however, slightly better values for coating A. Nuclear resonance broadening analysis showed coating A to be essentially stoichiometric TiN, while B showed a gradually increasing nitrogen content towards the surface. Scanning electron micrographs revealed columnar microstructure with coating A while B was almost featureless. The columnar microstructure of coating A is suggested as an explanation for the poor performance of coating A as compared to coating B.
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81.40.Pq Friction, lubrication, and wear
62.20.Qp Friction, tribology, and hardness
68.35.Gy Mechanical properties; surface strains

Some observations of gear‐cutting operations with TiN‐coated hobs and shaper cutters

Predrag Stosic

J. Vac. Sci. Technol. A 4, 2768 (1986); http://dx.doi.org/10.1116/1.573677 (2 pages)

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As a big manufacturer of tractor gear boxes, IMT was specifically interested in improving productivity with TiN‐coated hobs and gear‐shaper cutters, due to the potential benefits which TiN coatings offer on HSS gear‐cutting tools. For this reason, a number of comparative tests were recently carried out with both uncoated and TiN‐coated hobs and shaper cutters. The studies and tests included microscopic examinations of testing tools at the end of each shift as well as before each resharpening of hobs and shaper cutters and recorded the number of gears produced, resharpening depth, and number of resharpenings. At the same time, the main types of tooth wear, such as cutting‐edge dullness and cratering were observed and adequately examined. Test results definitely proved that an effective contribution to maximum productivity could be expected by exploitation of those characteristics of TiN coatings which permit higher cutting speeds and feeds and therefore reduce machining time.
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62.20.Qp Friction, tribology, and hardness

Microstructural and microchemical characterization of hard coatings

J.‐E. Sundgren, A. Rockett, J. E. Greene, and U. Helmersson

J. Vac. Sci. Technol. A 4, 2770 (1986); http://dx.doi.org/10.1116/1.573678 (14 pages) | Cited 7 times

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There is presently a rapidly expanding interest in the use of hard wear‐resistant coatings, especially transition metal nitrides and carbides which are among the hardest and most chemically inert compounds known. The complex bonding structure in these materials—a mixture of covalent, metallic, and ionic components—gives rise to a unique set of properties which has resulted in a wide range of applications. Nevertheless, there is still no detailed understanding of the relationship between film deposition parameters and the resulting microchemistry, microstructure, and hence physical properties, of the coating. This is primarily because the coatings are, in most cases, poorly characterized. In this paper, microchemical and microstructural analysis techniques appropriate for the study of hard coatings are critically reviewed and compared. The relative advantages and disadvantages of each technique are discussed together with possible problems in data interpretation which can arise due to measurement artifacts.
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68.55.-a Thin film structure and morphology
68.60.Bs Mechanical and acoustical properties
82.80.-d Chemical analysis and related physical methods of analysis
62.20.Qp Friction, tribology, and hardness

Low temperature oxidation behavior of reactively sputtered TiN by x‐ray photoelectron spectroscopy and contact resistance measurements

C. Ernsberger, J. Nickerson, T. Smith, A. E. Miller, and D. Banks

J. Vac. Sci. Technol. A 4, 2784 (1986); http://dx.doi.org/10.1116/1.573679 (5 pages) | Cited 24 times

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Electronic and electrical contact applications of TiN require a detailed understanding of the surface chemistry behavior in a variety of operating environments. For electromechanical contacts, contact resistance is the figure of merit and is a strong function of the structure and chemistry of the surface region. Thin (on the order of a few monolayers) insulating or semiconducting overlayers on a metallic conductor can raise contact resistance several orders of magnitude. In this study low temperature (22–100 °C) oxidation kinetics of reactively sputtered Ti and TiNx coatings of varying composition exposed at three humidity levels have been examined by x‐ray photoelectron spectroscopy (XPS) depth profiling, angle resolved XPS, and contact resistance measurements. Equilibrium overlayer conductivities can be up to nine orders of magnitude greater for TiN1.0 than Ti metal.
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81.05.Je Ceramics and refractories (including borides, carbides, hydrides, nitrides, oxides, and silicides)
81.65.-b Surface treatments
73.40.Cg Contact resistance, contact potential
73.61.Ng Insulators
82.65.+r Surface and interface chemistry; heterogeneous catalysis at surfaces

Characterization of nitride coatings by Auger electron spectroscopy and x‐ray photoelectron spectroscopy

S. Hofmann

J. Vac. Sci. Technol. A 4, 2789 (1986); http://dx.doi.org/10.1116/1.573680 (8 pages) | Cited 27 times

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The dependence of technically important properties of wear resistant nitride coatings on chemical composition requires advanced methods of compositional analysis to establish optimized fabrication processes. High spatial resolution and chemical bonding specificity are provided by such techniques as Auger electron spectroscopy (AES) in the form of scanning Auger microscopy (SAM) and x‐ray photoelectron spectroscopy (XPS). A survey is given for the study of reactively sputter deposited Ti–N, Hf–N, and Ti–Al–N coatings on high‐speed steel substrates using point, line, and in‐depth distribution analysis by SAM in conjunction with sputter profiling. Capabilities and limitations of quantitative AES to determine the influence of processing parameters on coating composition are presented. XPS gives additional information on chemical bonding and on quantification. This is particularly important in cases of peak overlapping in Auger spectra (e.g., TiN).
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68.55.Nq Composition and phase identification
68.60.Bs Mechanical and acoustical properties
82.80.Pv Electron spectroscopy (X-ray photoelectron (XPS), Auger electron spectroscopy (AES), etc.)
68.35.B- Structure of clean surfaces (and surface reconstruction)

Studies of interfacial composition of TiN films formed by plasma‐assisted chemical vapor deposition using an in situ scratching device

M. R. Hilton, A. M. Middlebrook, G. Rodrigues, M. Salmeron, and G. A. Somorjai

J. Vac. Sci. Technol. A 4, 2797 (1986); http://dx.doi.org/10.1116/1.573681 (4 pages)

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The interfacial composition of plasma‐assisted chemical vapor deposited TiN films on M2 tool steel is reported. An in situ scratcher with a scratch adhesion test type diamond stylus was used to create scratches in ultrahigh vacuum (UHV). Auger electron spectroscopy analysis of the adhesive mode failures revealed a sharp chlorine concentration gradient at the exposed surface representing the prior interface. The scratch removal technique data is compared to sputter depth profile data. Scanning electron microscopy and energy dispersive spectroscopy investigation of the scratches following the UHV work is also presented and discussed.
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68.35.Dv Composition, segregation; defects and impurities
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
62.20.Qp Friction, tribology, and hardness
68.60.Bs Mechanical and acoustical properties

States of residual stress both in films and in their substrates

A. J. Perry and L. Chollet

J. Vac. Sci. Technol. A 4, 2801 (1986); http://dx.doi.org/10.1116/1.573682 (8 pages) | Cited 7 times

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The study confirms that the sin2 ψ method can be used to determine the stress both in films and in their substrates. The application‐oriented model system chosen is Ti(CN) deposited onto high‐speed steel (HSS) and stainless steel by ion plating with a film deposited on HSS by chemical vapor deposition (CVD) as reference. The films are fine grained, hard, and strongly textured. The stress in the CVD film of 920 MPa compressive could be attributed to differential thermal contraction effects; in ion plated films it was over 4000 MPa. The stress in the steels was low and not measurably affected by the ion plating process. Problems in measurement and interpretation associated with texture, fluorescence, and penetration depth are illustrated and discussed.
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68.60.Bs Mechanical and acoustical properties
68.35.Gy Mechanical properties; surface strains
81.15.Jj Ion and electron beam-assisted deposition; ion plating
81.40.-z Treatment of materials and its effects on microstructure, nanostructure, and properties

Internal stress and adherence of titanium nitride coatings

D. S. Rickerby

J. Vac. Sci. Technol. A 4, 2809 (1986); http://dx.doi.org/10.1116/1.573683 (6 pages) | Cited 7 times

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Titanium nitride coatings were deposited on various substrates by sputter ion plating and the state of stress was determined by the sin2 ψ method. The lattice distortions that occur in the nitride coatings have been resolved in terms of a macrostrain and microstrain, as determined from the breadth of the x‐ray reflections, and the origins of each are discussed. The internal stress present in a coating is shown to consist of two components, one thermal in origin and the other structural, and that its sign and magnitude varies with substrate material and bias potential. During cooling from deposition temperature partial relaxation of this internal stress (macrostrain) occurs via two mechanisms, plastic deformation of the substrate and yield of the film. The internal stress was completely relaxed on dissolution of the substrate, accompanied by a decrease in the lattice parameter of the film. By comparing the results from substrates biased and unbiased during deposition, and measurements made on adherent and free‐standing coatings, the microstrain measurements have been separated into two parts, one due to distortions at the grain boundaries and one due to defects in the crystallites. A model is proposed that accounts for all the experimental observations; this also provides an explanation for the distortions from cubic symmetry reported in titanium and hafnium nitride films.
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68.60.Bs Mechanical and acoustical properties
62.20.Qp Friction, tribology, and hardness
68.35.Gy Mechanical properties; surface strains
81.40.Pq Friction, lubrication, and wear

Acoustic emission during chromium electrodeposition

M. E. Todaro, G. P. Capsimalis, and E. S. Chen

J. Vac. Sci. Technol. A 4, 2815 (1986); http://dx.doi.org/10.1116/1.573684 (4 pages)

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The authors used acoustic emission to study crack formation during the electrodeposition of chromium over a range of temperatures and current densities which characterize the transition from high contraction (HC) to low contraction (LC) chromium. Several characteristics of the acoustic emissions were examined, including the amplitude distribution, signal energy, emission rate, count rate, and frequency spectrum. The acoustic emission technique detected the onset of cracking and yielded useful information regarding the number of cracks. Such information acquired during the actual deposition process can be an invaluable aid in determining the quality of the deposit and in developing improved chromium coatings. Experimental data were acquired and analyzed using commercial acoustic emission instrumentation, including standard piezoelectric transducers. The deposition bath was a standard aqueous solution of 250 g/l chromic acid and 2.5 g/l sulfuric acid. The solution temperature and deposition current density were varied to obtain deposits of differing crack content. The substrate was electropolished carbon steel.
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62.20.M- Structural failure of materials
81.40.Np Fatigue, corrosion fatigue, embrittlement, cracking, fracture, and failure
81.15.Lm Liquid phase epitaxy; deposition from liquid phases (melts, solutions, and surface layers on liquids)
62.65.+k Acoustical properties of solids

Very hard W–C coatings on stainless steel by rf reactive magnetron sputtering

P. K. Srivastava, V. D. Vankar, and K. L. Chopra

J. Vac. Sci. Technol. A 4, 2819 (1986); http://dx.doi.org/10.1116/1.573685 (8 pages) | Cited 5 times

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Tungsten carbide films having a single‐phase B1 fcc structure have been deposited by rf reactive magnetron sputtering on stainless‐steel substrates held at 500 °C. These films show a very high microhardness (∼3200 kgf/mm2) as compared to the bulk value (∼1800 kgf/mm2) and have very good adhesion (2.25×107g/cm2). The friction and wear of these films have been investigated by a pin and disk machine. A friction coefficient of 0.13 has been obtained. The wear resistance of coated stainless steel is reduced by a factor of 20. Further improvement in adhesion and reduction in both friction coefficient and wear rate is observed when an interlayer of Ti, Ta, W, Mo, and Si is introduced in between the stainless‐steel surface and W–C coatings. The relationship between the mechanical properties and the structure of the coatings and interlayers is discussed.
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68.60.Bs Mechanical and acoustical properties
68.35.Gy Mechanical properties; surface strains
68.35.B- Structure of clean surfaces (and surface reconstruction)
68.55.-a Thin film structure and morphology

On the morphology of thermochemically produced Fe2B/Fe interfaces

A. J. Ninham and I. M. Hutchings

J. Vac. Sci. Technol. A 4, 2827 (1986); http://dx.doi.org/10.1116/1.573686 (5 pages)

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A number of steels have been thermochemically boronized, and the morphology and composition of the boride layers have been examined. Theories to explain the morphology of the boride/substrate interface and based upon preferential diffusion of boron along the crystal ‘‘c’’ axis, or upon stress fields at the boride/substrate interface are discussed. These theories are shown to be unable to explain the morphology of the interface that is formed when high carbon steels are boronized. A new mechanism of boride growth is described which can account for the boride/substrate interface morphology in all cases. This involves the presence of impurities, which in plain carbon and low alloy steels controls the interface morphology by locally reducing the boride growth rate. The proposed mechanism is confirmed by the results of microanalysis, and has important consequences for the selection and specification of steels for boronizing.
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68.35.B- Structure of clean surfaces (and surface reconstruction)
68.35.Fx Diffusion; interface formation
68.35.Dv Composition, segregation; defects and impurities

Chemical vapor deposition and physical vapor deposition coatings: Properties, tribological behavior, and applications

K.‐H. Habig

J. Vac. Sci. Technol. A 4, 2832 (1986); http://dx.doi.org/10.1116/1.573687 (12 pages) | Cited 3 times

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The main differences between chemical vapor deposition (CVD) and physical vapor deposition (PVD) processes are discussed in relation to a number of properties which are important for the functional behavior of coatings: chemical composition, phase composition, microstructure, thickness, hardness, texture, internal stresses, morphology, and roughness; each of which is discussed. Results of friction and wear tests which were performed under different conditions are reported, which reveal important aspects of the tribological behavior of different coatings. Examples of the application of CVD and PVD coatings are presented which show the possibilities for decreasing friction and wear of tools and machine elements.
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81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
81.65.-b Surface treatments
81.40.Pq Friction, lubrication, and wear
68.55.-a Thin film structure and morphology

Friction and wear reduction in tool steel by ion beam enhanced TiN deposition

Hillary Solnick‐Legg, K. O. Legg, J. G. Rinker, and G. B. Freeman

J. Vac. Sci. Technol. A 4, 2844 (1986); http://dx.doi.org/10.1116/1.573688 (6 pages) | Cited 2 times

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A wear‐resistant surface has been produced on M2 and M43 tool steel by an ion‐assisted coating technique in which a TiN based film is ion beam mixed into the surface. Electron spectroscopy for chemical analysis shows the film to be a combination of TiN and TiO2, grading into the substrate. Friction and wear are greatly reduced and material pickup is virtually eliminated. Even when the coating has been worn away the friction and wear rate remain below those of the untreated steel, because of the presence of an ion‐implanted substrate. The results are discussed with reference to changes in the wear mechanisms.
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81.40.Pq Friction, lubrication, and wear
81.15.Jj Ion and electron beam-assisted deposition; ion plating
81.05.Bx Metals, semimetals, and alloys
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.

Tribological properties of MoNx coatings in contact with copper

J. Valli, U. Mäkelä, and H. T. G. Hentzell

J. Vac. Sci. Technol. A 4, 2850 (1986); http://dx.doi.org/10.1116/1.573689 (5 pages) | Cited 5 times

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In metal forming processes, coatings can be used to prevent adhesion between the tool and the workpiece in order to increase the lifetime of the tool. A new promising coating material for copper forming tools is MoNx, which has low galling tendency in an unlubricated contact with copper. MoNx coatings were deposited in a magnetron sputtering system. Tribological tests were carried out in a pin‐on‐disk tribometer. Also the adhesion and structure of the coatings were characterized. The lowest coefficient of friction and the lowest wear rate against copper was measured when the nitrogen concentration in the coating was 15 at. %–18 at. % and the Vickers microhardness about 2000 HV at a load of 10 g.
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62.20.Qp Friction, tribology, and hardness
68.35.Gy Mechanical properties; surface strains
68.60.Bs Mechanical and acoustical properties

Summary Abstract: A physical vapor deposition technique for plating gun tubes

J. R. White

J. Vac. Sci. Technol. A 4, 2855 (1986); http://dx.doi.org/10.1116/1.573690 (2 pages)

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Abstract Unavailable
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81.15.Jj Ion and electron beam-assisted deposition; ion plating

Improving the wear resistance by forming hard metal matrix–ceramic composite surface layers

Khershed P. Cooper

J. Vac. Sci. Technol. A 4, 2857 (1986); http://dx.doi.org/10.1116/1.573691 (5 pages) | Cited 2 times

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Using an oscillating high energy laser beam, wide melt pools were formed on the surface of Inconel 625 alloy samples. Metal carbide particles, such as WC and TiC, were injected into the melt to form hard metal matrix–ceramic composite layers upon solidification. The injected layers were uniformly distributed in the carbide phase but exhibited variations in microstructure and microhardness. These variations were a result of carbide dissolution which depended upon the type of carbide and the thermal conditions within the melt pool. The wear behavior of the injected surface was characterized by coefficient of friction (μk) measurements. In contact with a hard 52100 steel ball, the μk values of the treated surface varied from 0.33 to 0.44 after a series of cycles. This compared with a value of 0.7 for the untreated surface. Observed wear modes included matrix abrasion and wear debris deposition, the extent and nature of which depended upon the matrix microhardness and the wear mechanism. The effects of carbide type and size on friction wear behavior of Inconel 625 are also discussed. Results show that Inconel 625 injected with 45–75 μm WC performs best under sliding friction conditions.
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81.40.Pq Friction, lubrication, and wear
62.20.Qp Friction, tribology, and hardness
68.35.Gy Mechanical properties; surface strains
81.05.Bx Metals, semimetals, and alloys

The effect of crystallization on the wear resistance of electroless deposited Ni–P amorphous coatings

Luo Shoufu, Ma Erming, and Li Pengxing

J. Vac. Sci. Technol. A 4, 2862 (1986); http://dx.doi.org/10.1116/1.573692 (5 pages)

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The changes in structure as well as the hardness and wear resistance of two electroless deposited Ni–P amorphous coatings (with phosphorus content 5.11 and 11.44 wt. %, respectively) after various heat treatments were studied by transmission electron microscopy, scanning electron microscopy (SEM), differential thermal analysis, and x‐ray diffraction. The results show that the hardness and wear resistance go through maximum values with increasing annealing temperature, but the peak of the wear resistance appears at a higher annealing temperature than that of the hardness for 11.44 wt. % P coating. At a given temperature, similar results were obtained with increasing annealing time. It was revealed by structural analysis that the increase of hardness is due to the formation of the Ni3P phase within the crystallized coatings during heat treatment. The lowering of hardness after the peak value is due to the decrease in lattice defects and the coarsening of grains as a result of recrystallization of the coatings. Different morphologies of the wear tracks were observed in the SEM for the amorphous and crystallized coatings. It is suggested that the wear of Ni–P coatings is influenced not only by its hardness, but also is closely related to the toughness of the coating and the adhesion between the substrate and the coating.
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81.40.Pq Friction, lubrication, and wear
62.20.Qp Friction, tribology, and hardness
68.55.-a Thin film structure and morphology
81.40.Gh Other heat and thermomechanical treatments

Tribological properties of metal/carbon coatings

E. Bergmann and J. Vogel

J. Vac. Sci. Technol. A 4, 2867 (1986); http://dx.doi.org/10.1116/1.573649 (3 pages)

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Dimigen and Hübsch discovered that carbon‐rich metal/carbon coatings that are deposited with a process combining reactive magnetron sputtering with plasma activated chemical vapor deposition show promising tribological properties. We investigated some of these for metal/carbon compounds of chromium, tungsten, and titanium of different stoichiometry. Friction coefficients against high‐carbon low‐alloy steel were measured in a three pin‐on‐disk configuration. Three‐body wear resistance was evaluated using a modification of the three pin‐on‐disk equipment, where a polishing powder suspension was fed continuously into the tribocontact. The results showed a strong dependence of the tribological properties on composition. The variation in the three‐body wear resistance of tungsten carbon compounds agreed with Rabinowicz’s model for the dependence on Vickers hardness.
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62.20.Qp Friction, tribology, and hardness
68.60.Bs Mechanical and acoustical properties
68.55.Nq Composition and phase identification
81.40.Pq Friction, lubrication, and wear

Predicted wear resistances of binary carbide coatings

Bruce M. Kramer

J. Vac. Sci. Technol. A 4, 2870 (1986); http://dx.doi.org/10.1116/1.573650 (4 pages) | Cited 4 times

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A mechanistic model of the tool wear process has been presented [B. M. Kramer and P. K. Judd, J. Vac. Sci. Technol. A 3, 2439 (1985)] that includes the effects of both the abrasion of the tool material by inclusions within the workpiece and the chemical dissolution of the tool material into the matrix of the workpiece. Machining tests have been run on steel with titanium carbide coated tooling and the resulting test data have been employed to produce a rough calibration of the proposed model. This model has been used to predict the wear resistances of the other group IV B carbides and of the (Ti,Hf)C system in the machining of steel.
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