The iron sulfide coatings prepared by plasma spraying and their friction-reduction performance

The plasma spraying technique was used to get the solid lubrication iron sulfide coating on the 1045 steel. The iron sulfide powder, which was employed to spray, was ball-milled with granularity of 40 μm. AFM and SEM were made use of observing and analyzing the morphologies of surface and worn scar of the coatings. A scratch testing machine was utilized to measure the bond strength between substrate and coating. The coating was formed by the accumulation of irregular FeS grains. The bond strength between the coating and substrate was about 32 N belonging to the mechanical bonding. The friction test of the FeS coatings, tested on a ring-on-block tester, showed that the plasma spraying FeS coatings possessed the remarkable friction-reduction performance. The worn failure mechanism of the coatings was flaking off.