Microstructure and tribological properties of sulphide coating produced byion sulphuration

Based on the principle of ion-nitriding a new ion sulphuration technique wa s developed. Its basic process and advantages compared with the traditional electrolytic method were described. The sulphuration coating was formed ma inly by a chemical conversion, not only by a diffusion process. Its thickne ss was generally in the range of several to several tenth micrometers. X-ra y diffraction, SEM, and EDAX were employed to analyze the microstructure, m orphology, and composition of sulphide coating. The results showed that the sulphide coating was mainly composed of FeS with layered hexagonal lattice as well as a certain amount of FeS,. So that it showed a pretty good solid lubrication behavior. The tribological properties of ion sulphuration coat ings on the 52100 and 1045 steel substrates were tested on SRV and Amseler testing machines. It can be found from the testing results that the sulphid e coating can significantly decrease the friction coefficient and increase the wear resistance of materials. The mechanism was discussed in detail bas ed on the microanalyses of sulphide coating as well. (C) 1999 Published by Elsevier Science S.A. All rights reserved.