The friction–reduction model of the iron sulfide film prepared by plasma source ion sulfuration

A new plasma source method, low temperature ion sulfuration, was utilized to prepare the FeS film on the AISI 1045 steel surface. The anti-friction property was tested on the ball-on-plate tester and the results showed the film holds the excellent performance. AFM and SEM were adopted to analyze the morphologies of surfaces and wear scars of the FeS film. SAM was employed to detect the surface element distribution with depth. The physical friction–reduction model of the FeS film was formed and was verified by SAM analysis. Results showed that in the course of friction, FeS film formed a dynamic balance between decomposing and recomposing. Therefore the thin FeS film could last a long solid lubrication time.