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.