Computer controlled detonation spraying of WC/Co coatings containing MoS2 solid lubricant

Abstract

Composite WC/Co+MoS2 coatings were deposited onto steel substrates by Computer Controlled Detonation Spraying using three spraying modes: very cold, cold and normal. Maximal content of MoS2 in a sprayed powder was 10wt.%. Characterization of coatings was made with chemical and phase analyses, microhardness measurement, morphology and microstructure investigation. X-ray diffraction study shows that residual MoS2 exists only in coatings obtained at very cold and cold spraying modes. At normal spraying mode complete decomposition of the solid lubricant occurs during spraying. From the engineering point of view, the coating applied at the cold mode using a powder containing 10wt.% MoS2 is the most promising. Such a coating has microhardness of 650 HV0.2 and a porosity of 10%.