Effect of Ni Addition on Microstructure and Tribological Properties of Plasma-Sprayed MoSi2 Coatings

摘要

A MoSi2 coating with Ni addition (10vol.%) and a pure MoSi2 coating were fabricated by atmospheric plasma spray on AISI 316 stainless steel substrate. The coating phase composition, microstructure and basic properties were characterized. The tribological behavior and sliding properties against metal (stainless steel) and hard material (WC-Co) were compared under 5-50N loads. The results showed that the addition of Ni improved the density and bonding strength of MoSi2 coating, while it decreased the microhardness to some degree. The wear test results indicated that the addition of Ni reduced the friction coefficients and wear rates of the MoSi2 coating when sliding against WC-Co. However, the addition was detrimental to the wear resistance when sliding against stainless steel. The worn surfaces of the coatings under low and high loads were observed in detail, and the wear mechanisms were explained.