Papers by Keyword: Ion-Plating

Abstract: An increasing interest has been being taken in hydrogen as a clean energy for solving the global environmental problems. In order to use the hydrogen in safety, investigation on the hydrogen behavior is required. Although hydrogen microprint technique (HMPT) has been known to be effective to investigate the hydrogen behavior, the low detection efficiency for hydrogen was reported. Ion-plating (IP) was reported to increase the detection efficiency in HMPT emitted from the specimen by plastic deformation. On the other hand, no such increase was found for hydrogen permeating through the specimen ion-plated with substrate heating in the previous study by the authors. In the present study, the sheet samples of pure aluminum with 99.99% purity were dehydrogenated and subjected to (a) holding in the IP chamber, (b) bombardment with Ar ions, (c) substrate heating after the bombardment and (d) holding in air. Hydrogen behavior in these samples has been investigated by means of thermal desorption spectroscopy (TDS). The amount of desorbed hydrogen was evidently larger in the conditions of (a) and (b) than in (d). However, the amount of desorbed hydrogen was decreased by the substrate heating (c) to the same level as in (d).

Abstract: The abutment screw loosening of dental implant system has been remained problem in restorative practices. Surface treatment of screw plays a role of preventing screw from loosening in implant screw mechanism. The purpose of this study was to investigate surface characteristics of ZrN and TiN coated dental gold-screw and Ti-screw by ion-plating method and to evaluate wear resistance, surface roughness, and film adhesion on the screw surface using field emission scanning electron microscopy(FE-SEM), energy dispersive x-ray spectroscopy(EDX), micro-diamond scratch tester, vickers hardness tester, and surface roughness tester. The surface of gold screw and GoldTite is more smoothly than ones of other kinds of non coated screw. The ZrN and TiN coated surface is more smoothly than ones of other kinds of screw. The hardness of TiN and ZrN coated surface showed higher than that of non coated surface. The TiN coated titanium screw and ZrN coated gold screw have a good wear resistance and adhesion on the surface. The surface of ZrN coated screw showed low surface roughness compared with the surface of TiN coated screw.

Abstract: Ti-50.6 at.% Ni shape memory alloy was coated with tantalum using multi arc ion-plating technique with the aim to increase its radiopacity and biocompatibility. The surface characteristics were investigated by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The results of XPS survey spectra show that a thin oxide film are formed inside tantalum coating as a result of natural passivation of Ta in atmosphere. The hemocompatibility was evaluated in vitro by clotting time and platelet adhesion measurement. The results of our study showed that the clotting time of tantalum was higher than that of the TiNi alloys and no sign of accumulation and only slight pseudopodium was observed on the tantalum coatings, suggesting that the tantalum coatings can improve the biocompatibility of TiNi alloy.