Effect of Ag alloying on microstructure, mechanical and electrical properties of NiAl intermetallic compound

In this paper, the effects of Ag on microstructure, mechanical and electrical properties of NiAl intermetallic compound were investigated. The present results show that the NiAl–Ag alloys consisted of two phases: β-NiAl and Ag-rich solid solution. The amount of the Ag-rich phase increased with increasing Ag content. Ag has very low solubility in NiAl and they form pseudo-binary monotectic systems. The addition of 0.5–1at.% Ag to NiAl increased its strength while the addition of more than 1at.% Ag decreased its strength. The strengthening and weakening effects come from solid solution hardening and second ductile phase softening. In addition, Ag alloying can improve NiAlʹs room temperature compressive ductility. The NiAl–Ag alloy has high hardness and electrical conductivity that make it an attractive candidate for electrical contact material.