Plasma Sprayed Metal-Ceramic Coatings and Modification of Their Structure with Pulsed Electron Beam Irradiation

Composite powder obtained from mechanically crushed titanium carbide-metal binder cermet compacts deserves special mention for plasma spraying of wear-resistant coatings. However, cermet coatings sprayed using this powder have comparatively high porosity. The porosity causes the mechanical strength of the coating to largely deteriorate, and it also lowers the strength of the bond between the coating and the substrate. Computational and physical experiments were performed in this area to reveal the possibilities offered by pulsed electron beam irradiation for structural modification of 70 vol.%TiC-(Ni-Cr) powder coatings. The authors evaluated optimal values of process parameters for suitability in implementing a controlled thermal treatment of coatings under conditions of solid-liquid interaction of components in the cermet composition with each other and with the steel substrate. Evolution of the structure and physical properties of the cermet coatings under rapid heating and following cooling in a wide range of temperatures typical of pulsed irradiation conditions have been examined.