Microstructure and wear behaviour of self-fluxing alloy coatings reinforced by WC-Co

The wear behaviour of Ni-base self-fluxing alloys, thermally sprayed as protective layers on martensitic stainless steel substrates, is affected by several factors, such as the microstructure of the coatings and their adhesion to the substrate, the porosity and the hardness of the surface. In this study, the mechanical wear properties of thermally sprayed self-fluxing alloys with different additions of Cermet powders (10, 20 and 30% WC-Co) were investigated using the pin-on-disk method. Moreover, it was highlighted that after the flame fusion process the morphology of the layers has been greatly improved. Based on scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) analysis the evolution of the metallic matrix reinforced by ceramic phases consisting of carbides, borides and silicide's was pointed out. Micro-hardness measurements were carried out as well, in order to evaluate the influence of flame fusion process on the coating hardness. The investigations revealed that the addition of up to 30% Cermet powder to self-fluxing alloys leads to the improvement of the wear resistance of the protective coatings, extending the range of practical applications of self-fluxing layers.