2009 年 59 巻 2 号 p. 70-74
Utensils made of titanium and it's alloys have recently been employed in various branches of medical treatment, welfare, recreation and sports due to their light weight, excellent corrosion resistance and artistic design potential. However, utensils made of titanium and it's alloys are more subject to easy seizure, scuffing, abrasive wear and adhesive wear than utensils made of steel. This study seeks to improve the tribological properties of titanium and it's alloys by applying a porous anodic oxide film anodized in a suitable electrolytic solution made up H2SO4, H3PO4 and H2O2. The method employs 5,000 Hz pulses in direct current to anodize utensils and impregnate them with molybdenum sulfide while they adsorb zinc sulfide using electrophoresis at the same time. Based on this study, we were able to attain a lower friction coefficient, a narrower wear trace, and a lower ratio of wear volume after this surface treatment. We presume that the chemical composition of zinc sulfide resolved during friction and wear converts molybdenum sulfide to MoS2, a well known lubricant, as a result of reciprocal action.