A modified pin-on-disc wear test technique and conversion electron Mössbauer spectroscopy (CEMS) have been used to characterize the tribological and microstructural properties, respectively, of pure Fe implanted with N and Ar ions at high current densities. CEMS measurements were made before and after wear testing. For the lubricated, mild adhesive wear conditions used here, no evidence was found for iron-nitride dissolution or N atom migration. Disordering of γ'-Fe4N did occur as a result of the wear process. All Nimplanted surfaces were tribologically superior to the Ar-implanted surface and an extremely wear-resistant surface layer about 30–50 nm thick was produced with a dose of 8×1016 N atoms/cm2, at a dose rate of 100 μA/cm2. However, once this layer was worn away the wear rate returned sharply to that of unimplanted pure Fe. A high retained N dose has been observed even for a dose rate of 750 μA/cm2 during which the sample reached 280°C.

A study has been made of the relationship between crystal structure and hardness of N-implanted Fe-surface layers. The substrates used were polycrystalline Fe-sheets 1 mm thick with a purity of 99.9 %. The ion implantation of 14N+ was performed with doses ranging from 7.5×1016 to 1×1018 ions/cm2 at an energy of 100 keV. The substrate temperatures during implantation were kept at -40, 20, 100 and 200 °C. The crystal structure of N-implanted layers was identified by X-ray diffraction method (XRD). The near surface hardness was measured by a Knoop hardness tester. The XRD patterns revealed that the iron-nitride peculiar to each implantation condition was formed, and the iron-oxide was embedded in the nitrides in case of higher temperature implantation. N-implantation led to hardness increase, whose degree also depended on implantation conditions. The comparison between the structure and hardness of implanted layers indicated that, among the phases of iron-nitrides produced by 20 °C implantation, ε-phase is the hardest and the γ-Fe203 and γ'-Fe4N formed by 200 °C implantation are harder than the ε-phase nitrides. These results are discussed with respect to the surface composition estimated by Rutherford backscattering spectrometry (RBS) using 1.5 MeV 4He+-ions.

A study has been made on friction and hardness of boron and nitrogen ion implanted Fe-Cr alloys. Ion implantation has been carried out with doses ranging from 5 wt% up to 20 wt% at energies of 50, 100 and 150 keY at room temperature. Reciprocal traces for friction coefficient measurements were performed by using a Bowden-Leben tester at a low speed without lubricant. Hardness was measured by using a micro-Vickers tester at a load of 2gf. Hardness of the specimen increases after the implantation with either of ion species. Friction measurements with reciprocal sliding show that a life-time of decreased friction coefficient depends on implanted ion species, Cr concentrations and acceleration energies. For B+- implantation, the lower the chromium contents are, the longer a decreased friction coefficient lasts. Meanwhile, the friction reduced by nitrogen implantation lasts longer for higher chromium content substrates. Dependence of friction coefficient on an acceleration energy is discussed for B+-implantation.

The influence of the growth conditions on the composition, microstructure, and mechanical properties of TiN formed with low energy Ar+ ion bombardment during reactive physical vapor deposition was studied. The ratios of the incident ion and atom fluxes at the growth surface were varied systematically and were found to have a strong influence on both the composition and the microstructure of the films. These changes correlated well with measured changes in mechanical and optical properties. The films were examined using Auger electron spectroscopy, transmission electron microscopy, and their mechanical properties were studied using hardness, friction, and wear testing.

One of the advantages of the ion beam assisted deposition process is its controllability of the processing parameters such as: ion-to-atom arrival ratio and the ion energy. In this study, the effects of the nitrogen ion energy (from 1 KV to 30KV) on the TiN film morphology and microstructures were systematically investigated as a function of ion-to-atom arrival ratios, using TEM, XTEM, SEM, ESCA and other analytical techniques.

The method of Ion Beam Enhanced Deposition, (IBED), was used to produce hard films of i-BN, i-SixNy and i-TixNy. The friction, hardness, adhesion, and wear behavior of these nitride coalings were examined using a ball-ondisc Friction/wear tester. The friction and wear results were sensitive to stoichiometry and the presence of impurities (e.g., hydrogen) in the film as well as the choice of ball material (400C stainless steel or silicon nitride).

Cross section transmission electron microscopy was used to study the microstructure and interface structure of Cr films deposited by ion-assisted deposition as a function of the incident ion energy. High-energy ion bombardment (1 keV) was found to enhance the adhesion of the deposited film owing to the formation of an intermixed layer, whereas deposition with lowenergy ions (100 eV) was found to reduce or eliminate grain boundary porosity. A tailored Cr film with excellent adhesion and no grain boundary porosity was deposited by combining highand low-energy ion bombardment.

Multilayered Fe-Ti-C films consisting of eleven sublayers were vacuum deposited onto an AISI 304 stainless steel substrate and subsequently mixed using either 400 key Xe ions or an excimer laser operating at a wavelength of 308 nm. Ion mixing was accomplished in a two step process: the multilayers were first irradiated with 1×1017 Xe/cm2 at 520°C, after which half of the sample was irradiated with 5×1015 Xe/cm2 at 0 °C. Laser mixing was carried out at both i.i and 1.7 J/cm2 with the number of pulses varied between 1 and 10. Pin-on-disc studies revealed only slight differences between the two kinds of ion beam mixed samples, whereas the dry sliding properties of laser mixed samples were strongly dependent on the total fluence used. In the optimum conditions, similar friction coefficients were obtained on both kinds of samples.

We have investigated the properties of surface alloys of Ti formed by excimer laser melting and mixing of Ti overlayers on AISI 304 stainless steel substrates.The thickness of the initial Ti surface layers and the fluence and number of pulses used to mix the surface were varied to investigate a broad range of processing conditions. Samples were uniformly translated at different speeds under repetitive pulses of homogenized laser radiation at 308 nm to vary the number of pulses incident on the sample. We investigated the surface structure and composition, the wear and friction behavior, and the surface hardness of the resulting alloys.

The extent of mixing is observed by Rutherford backscattering spectroscopy to be proportional to the number of pulses incident on the sample. Amorphous surface layers are formed at some mixing levels with a composition which indicates that Ti substitutes for Fe in the stainless steel on a one to one basis. Incorporation of C from surface and interface contamination is observed but at a level much below that found in comparable ion implanted materials.

Friction coefficient measurements indicate that there exists an optimum level of mixing for each layer thickness. Excessive mixing degrades both the coefficient of friction and the wear performance in dry sliding tests.

As with the tribological measurements, the surface hardness showed a dependence on amount of mixing. The surface hardness of the as deposited samples was higher than that of the laser mixed samples, initially decreased with mixing, and finally increased with further mixing.

The alloy preferred for medical protheses, Ti6A14V, was ion implanted with oxygen and nitrogen alone and in combination at varying energies, 25 to 120 keV, and varying dose levels, 1017 to 1018 ions/cm2. Measurements were made of microhardness, corrosion resistance, chemical bonding of implanted species, and (with UHMWpo lyethylene) pin-on-disk wear and friction. The addition of oxygen to nitrogen implants now used in production was found to have little effect on wear or any other parameter.

The feasibility of growing stoichiometric thin films of BN by pulsed laser evaporation has been investigated. Films grown under high vacuum conditions were N-deficient. This result is consistent with thermodynamic calculations, which indicate that B metal formation, with concomitant N2 desorption, is energetically favored over BN formation. Stoichiometric films were grown in NH3 with substrate temperatures of 400, 500, and 1000°C. Analysis of films grown under these conditions by grazing incidence x-ray diffraction indicates the films to be highly oriented, hexagonal BN.

Effects of ion bombardment during deposition on the environmental durability of silver coatings have been examined. Films deposited under otherwise identical conditions were bombarded at different levels with 300 eV argon ions. Examination of the environmental durability of coatings revealed that films deposited with ion assisted deposition are more durable than evaporated coatings. Adhesion and scratch resistance of coatings were also improved as a result of ion bombardment.

This paper presents the results on the mechanism of the anodic oxidation on Al by means of ion–implanted marker Layer of xenon and RBS analysis techniques. ExperimentaLly, it has been shown that the mechanisms of anoulic oxidation on Al are different in the different elctrolytes. In the solution of 15%.wt sulphuric-acid, the anodic oxide film is formed by the react ion be tweeit metal rations at the metal/oxide interface and continuously migrated oxygen anions. While in the solution of 5%wt ammonium citrate, both tie migration of the metal cations and that of the oxygen anions contribute to the formation of the anodic flim, and the oxidization takes place in internal region of the oxide ftim or at lhe interface. The transport numbers for Al in 5%.wt ammonium citrate were found to vary with the voltage or current density front 44% to 64∼

We have deposited thin films of optical materials using ion beam sputtering and ion assisted deposition techniques. It is possible to obtain good quality film material deposited on substrates at temperatures lower than normally required. Ion assisted deposition influences film stoichiometry and packing density, which in turn determine optical and mechanical properties of the film material. We discuss two general indicators which appear helpful in predicting the degree to which these occur.

Rare-Earth Transition-Metal alloys such as Tb-Fe-Co are being studied and used as magneto-optic data storage materials. These materials are susceptible to oxidation by either oxygen or water vapor, particularly the rare earth component. Pitting corrosion is also a problem when protective overlayers have pinholes or a porous microstructure. Both degradation mechanisms are significant for application of this material to optical data storage. We have used ion assisted deposition (IAD) to produce protective overlayers of refractory oxides, such as Al2O2 and ZrO2. These layers were deposited both with and without IAD onto iron films and exposed to environments with controlled temperature and humidity. A scanning micro-reflectometer capable of detecting micrometer-sized pinholes was used to monitor the degradation of the iron layer with exposure time.

The annealing behavior of the optical properties of silicon nitride films (Si1-xNx) is described for films fabricated by ion beam assisted deposition. The data are needed for the precise manufacture of optical filters, where the index of refraction must be predicted from deposition parameters and film annealing history.

The reflection of homogeneous, amorphous samples deposited on (100) silicon substrates was measured from 500 to 3120 nm. Fits to the interference spectra were obtained over the range 1000 to 3120 nm to obtain the index of refraction vs wavelength as a function of film nitrogen content. Nitrogen atom fraction was varied from.2 to.58 by variation of the incident relative fluxes of nitrogen ion beam current to evaporant silicon flux. The films were annealed in argon at 450 C, 600 C, 750 C, and 1100 C and the measurements repeated. The systematic shifts in index of refraction with annealing temperature are described.

The use of ion-beam sputtered Al2O3 to passivate the mirrors of semiconductor injection lasers is described. Dense films, which offer considerable protection against corrosion, can be deposited without damage to the crystal surface. The overall quality of the passivation is demonstrated by long-term stress testing of the lasers.

Multilayer structures of Li20 and Ni were deposited onto polished fused quartz by the dual ion beam sputtering method. Optical and physical properties of the multilayer structure were evaluated. Reflectivity of multilayer mirrors at an incident angle of 79.6 deg. was 17% for 44Å(C-K line). There was good agreement with the calculated value considering the interface roughness and residual oxygen contamination in the Ni layer from the background of Li2O deposition.

The surface chemistry of silica glass implanted with N+ or P+ ions has been studied. The X-ray photoelectron spectroscopy (XPS) spectra of N(1s) for silica glass implanted with N+ shows the possibility of the formation of oxynitride glass. For the first time, the effect of the implantation of N+ and additional Si+ on the surface chemistry of silica glass has been studied and found to be significant in increasing the nitrogen concentration in the silica glass. The peak concentration of N increases several times, and does not change even if the sample is annealed at 900°C. The XPS spectra of P(2p) for silica glass implanted with P+ ions shows two interactions, both P-O and P-P. Therefore, the XPS spectra shows the possibility for the formation of phosphosilicate glass using P+ implantation into silica glass.

The microtopography of NiP films ( P content, 8.7–12wt.%; thickness, 40–50 μm ) prepared by electroless plating on 18–8 stainless steel plates for molds and etched with a 10 keV Ar+ ion beam was studied both by SEM observations and Talystep surface profile measurements. With films containing less than 9.6wt.%P, which is supposed to have a transient structure between the supersaturated solid solution and the amorphous solid, smooth surfaces were obtained down to a few micrometers of etch depth and after that craters were formed. As for the mechanism of crater formation, it is considered that Ni crystallites locally precipitate by ion bombardment and then are etched selectively. With amorphous films containing 10.6wt.%P, microcavities less than 0.02 μmRmax instead of craters were observed regardless of the etch depth. The ion beam etching of NiP films has been found to be very promising for the preparation of precision molds of various grades, e.g. for plastic lenses used in opto-electronics, by selecting P content according to the desired surface roughness and etch depth of a particular application.