Improvement of tribological properties of 9Cr18 bearing steel using metal and nitrogen plasma-immersion ion implantation

摘要

Metal plasma-immersion ion implantation (PIII) employing an improved vacuum-arc plasma source is performed on 9Crl8 bearing steels. Titanium and tantalum ions are implanted followed by nitrogen plasma-immersion ion implantation to yield a modified surface layer with superior wear resistance. The surface properties of the 9Crl8 bearing steel samples are evaluated by measuring the microhardness, wear properties and coefficient of friction. Elemental depth profiles and the chemical composition of themodified layer are acquired by Auger electron spectroscopy and X-ray photoelectron spectroscopy. The results show that the wear resistance of the samples implanted with (Ti + N) and (Ta + N) is better than that of the samples undergoing nitrogen Pillalone. The XPS results indicate the presence of nitride phases in the implanted layer. In this paper, the new improvements made on the metal-arc source are described. Using the new procedures incorporating both metal-ion and gas PIII, the surfaceproperties of 9Crl8 bearing steel are significantly improved.