Microstructures of the coatings and single deposited splats formed by advanced thermal spray processes have been investigated using two types of ion beam milling: one is broad argon ion beam for the cross-sectioning of thermal sprayed coatings in a cross section polisher and the other is focused gallium ion beam (FIB) for the cross-sectioning and transmission electron microscopy (TEM) sample preparation of single splats. The cross section of tungsten carbide cobalt (WC-Co) coatings fabricated by the polisher showed that it created a mirrored surface with minimized artifacts such as pull-outs of ceramic particles or smearing of pores which can be made by conventional metallographic preparations. A thin and locally re-thinned membrane of single nickel (Ni) splat was prepared by the FIB technique to observe the internal interface of particle/substrate in high resolution atomic scale images. It was found that the steel substrate was heavily deformed by the impact of a nickel particle with high kinetic and thermal energies. At the periphery region, the particle and the substrate were intimately bonded without any voids or gaps.

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  Electroless plating (ELP) process using Pt and Pd colloid catalyst has been developed. Au, Pt and Cu metal films with sufficient adhesion were successfully obtained without special treatment of substrate surfaces. Owing to the excellent catalytic property of the Pt nanoparticles, continuous gold thin films can be produced at room temperature using a simple cyanide-free gold electroless plating solution composed of chloroauric acid and hydrogen peroxide. Pd colloidal catalyst has been also developed for a novel Pt ELP process and for commercial Cu ELP process. The process requires no surface modifications for the immobilization of the catalyst, and by simple post-annealing the adhesion of the plated films to various polymer films can be improved dramatically. We have thus developed an environment-friendly etchingless ELP process without the use of toxic and hazardous substances.

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  Recent developments in plasma nitriding heat treatment technology were reviewed. The feature of plasma nitriding technology was introduced. Moreover, characteristics of the S phase, which was formed at 673 to 723 K in plasma nitriding of austenitic stainless steel, were explained. Finally, a new nitriding technology, — active screen plasma nitriding technology, was also explained.

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  Surface-treatment methods using ozone, such ozone gas treatment with UV light irradiation, immersion in ozone diluted water, and exposure to ozone gas are discussed herein. The objectives of performing ozone surface treatments are to reduce carbon-related contamination on the surface, prepare a clean substrate surface to fabricate a thin-film stacking with sharp interfaces, oxidize a surface to form high-quality oxide thin films, and passivate a metal surface to increase its corrosion resistance. These objectives are achieved because of the high oxidation ability of the ozone molecules and the oxygen radicals resulting from the ozone dissociation. Various applications of ozone surface treatment are also exemplified in this report to reveal their significant potential as surface-treatment tools.

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  Laser surface modification is one of the methods of surface modification. The use of lasers for the surface modification has been studied since 1960s. Laser surface modification includes a lot of methods such as laser transformation hardening, laser alloying, laser cladding and so on. They have been done to increase surface hardness, to improve wear resistance and corrosion resistance. In this review, some of them are introduced.

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  During pumping down of water molecules in a typical laboratory vaccum chamber (evacuation time constant: τ_p<1 s), we obserbed that the pressure decays exponentially on a time scale of sub-kilo seconds before it starts to decrease with nearly t⁻¹ time dependence. On the basis of the Henry-type adsorption-desorption rate equation on the chamber wall and the equation of evacuation, we discuss here that such an exponential decay curve can be realized in the quasi-steady state for pressure by the mathematical phase-space analysis. By applying this analysis to obserbed decay curves, we also show that the pressure decay is dominated by the chemisorbed water with an activation energy for desorption of ∼890 meV, which is in good agreement with the recent results of water adsorbed on oxide surfaces as investigated by surface science techniques. Our results establish a firm basis to describe evacuation process.

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  This study focused on the effect of temperature on a quartz friction pressure gauge, which uses a quartz oscillator as a sensor, for hydrogen sensing at room temperature. The temperature dependence of the nominal pressure and of the impedance and resonance frequency of the quartz oscillator were measured. The nominal pressure was found to depend on both the temperature and relative humidity in the range 0-100%, indicating the necessity for calibration. In contrast, the resonance frequency of the quartz oscillator was found to exhibit a linear dependence on temperature and to be independent of the relative humidity at atmospheric pressure. Thus, it can be used as an indicator of the temperature in order to calibrate the nominal pressure measured by the pressure gauge.

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