Microstructure and abrasive wear performance of chromium carbide reinforced Ni3Al matrix composite coating

A Ni–Al–Cr3C2 welding wire was produced by metal–powder–core technique. When the welding wires were welded on the surface of carbon steel, under the effect of the physical heat of arc, Ni reacted with Al to form Ni3Al and carbide particles reinforced Ni3Al matrix composite was formed. Cr3C2 was decomposed during welding and dispersed Cr7C3 with stripe shape formed, which strengthened the matrix significantly. The Cr7C3–Ni3Al interface has broadened into a zone of interdiffusion and a new phase M23C6, which indicates that a good bond has been formed. The pin-abrasion wear test showed that the abrasion resistance of Cr7C3/Ni3Al composite is six times higher than that of Stellite12 alloy at room temperature. The good wear resistance of Cr7C3/Ni3Al composite coating can be attributed to large volume fraction of carbides, high hardness, and good phases interface bond.