Influence of the substrate temperature and thesubstrate hardness on the splat formation of WCbasedcermet powders during HVOF spraying

The formation of splats during high-velocity oxy-fuel (HVOF) spraying is closely connected to the condition of the substrate surface. The appearance of the splats changes if the particles are deposited on surfaces with higher hardnesses and at higher temperatures. The effect of both influences were investigated using two cermet powders on a WC basis. An established WC-Co powder as well as a WC-FeCrAl powder were utilised. The appearances, splat diameters, the penetration depth into the substrate and the bonding to the substrate were investigated with the aid of scanning electron micrographs, a three-dimensional measurement of the splats and ion-polished cross sections.