Surface modification of steel by metal plasma immersion ion implantation using vacuum are plasma source

Employing an improved vacuum are plasma source, metal plasma immersion ion implantation (PIII) is performed on 9Cr18 bearing steel. Titanium, tantalum , molybdenum and tungsten ions are implanted followed by nitrogen PILI to r esult in a modified surface layer with superior wear resistance. The surfac e properties of the 9Cr18 bearing steel samples are evaluated by measuring the microhardness, wear property, coefficient of friction, as well as eleme ntal depth profiles and chemical composition of the modified layer. The res ults show that the wear resistance of the samples treated by metal plus nit rogen PIII is enhanced to a larger degree than that of the samples undergoi ng nitrogen PIII alone. The XPS results indicate that some nitride phases h ave been formed in the implanted layer. In this paper, we will also discuss the improvement on the metal vacuum are plasma source and experimental pro tocols. Using metal and gas PIII, the surface properties of 9Cr18 bearing s teel are enhanced significantly. (C) 1999 Elsevier Science S.A. All rights reserved.