Microstructure and Properties of Ni-Base Coatings Obtained by Micro-Plasma Arc Cladding Processes

Microstructure and properties of Ni-base coatings obtained by micro-plasma arc cladding was investigated. A uniform clad coating was obtained after optimizing the cladding parameters by using NiCrBSi powder. Microstructure of the coatings observed by optical and scanning electron microscopy (SEM) indicated a homogenized microstructure. It has no evident heat-affected zone and no porosity. The phase of the coating was formed by γ-N solid solution, nickel boride Ni3B, carbide Cr21.34Fe1.66C6 and Cr2B3 type chromium boride. Although it likes the laser cladding coatings, micro-plasma coatings has its own characteristic. In addition, the average microhardness and nanohardness of coatings which were much higher than the substrate were observed, and the distribution of the microhardness was drawn.