Abstract:
A Cr
3C
2-Ni
2Al welding wire was produced by pressureless sintering process in vacuum. When thewelding wires were welded on the surface of carbon steel , carbide particles reinforced Ni
3Al base composite wasformed due to the physical heat of arc and Ni-Al exothermic reaction. XRD shows that Ni react s with Al to formNi
3Al and Cr
3C
2 is dissolved during welding. Most of Cr and C react to form Cr
7C
3 phase except that a few dissolve into Ni
3Al mat rix. The size of Cr
7C
3 particles mainly depends on the cooling rate of different welding regions.In addition , as the solid solubility of Cr in Ni
3Al is much larger than that of C and Cr
3C
2 changes to Cr
7C
3 duringwelding , some graphites are formed in welding layers. The graphites mainly segregate on welding outer layers dueto it s low density and high melting point . The room and high temperature hardness of Cr
7C
3 / Ni
3Al composite ismuch higher than that of stellite alloys. It is predicted that Cr
7C
3 / Ni
3Al composite may become an att ractive potential candidate for high2temperature surface wear-resistant material.