Microstructure and Wear Properties of the Quasi-Rapidly Solidified NiAl/ Cr(Mo,Dy) Hypoeutectic Alloy

Abstract

The NiAl/Cr(Mo,Dy) hypoeutectic alloy was prepared by quasi-rapid solidification to investigate its microstructure and wear behavior. The results revealed that the quasi-rapid solidification refined the eutectic cell and NiAl/Cr(Mo) eutectic structure obviously. The alloy was composed of primary NiAl, fine NiAl/Cr(Mo) eutectic lamella and Ni5Dy phase. Compression test showed that the quasi-rapid solidification improved the mechanical properties of the alloy obviously. Wear test exhibited that alloy possessed excellent wear properties at about 1073 K, which should be ascribed to the lubricant film formed by amorphous and Cr₂O₃ and Al₂O₃ nanoparticles. The alloy also exhibited relative good wear properties at 673 K, which should be attributed to its high strength.