Microstructure and Tribological Properties of PlasmaSprayed Ni/MoS2 Solid Lubrication Coating

A composite Ni based MoS2 solid lubrication coating was prepared using the plasma spraying technology with optimized process parameters.The tribological properties of the composite Ni/MoS2 coatings in air and vacuum were studied with a ball-on-disk friction and wear tester under dry sliding condition,respectively.XRD,SEM and EDS were adopted to analyze the microstructures of the coating before and after wear tests.Results showed that the deposition quality of the coating was good.The content of lubricant MoS2 was high.But the compactability of the coating with many superficial micrometersized defects such as pores and cracks was relatively low.The composite Ni/MoS2 coating exhibited excellent friction-reduction properties both in air and in vacuum conditions.In vacuum,the wear loss was greater because the severe spalling of top layer resulted from breakthrough of the adjacent defects.In air condition,the wear loss of the coating was relatively low but its friction-reduction ability may be weakened for the oxidation of MoS2.