Superplasticity of a multiphase Ni-25Al-25Cr intermetallic alloy

Abstract

In the past decade significant improvement in high temperature strength, processing and design methodology for NiAl have been achieved. However, limited ductility and toughness as well as poor impact resistance continue to be critical issues which will impede near term production implementation. The most recent work on NiAl suggests that the room toughness of NiAl can be conveniently improved in-situ with refractory metal phases by directional solidification of pseudo-binary (e.g., NiAl-Cr) and -ternary(NiAl-Cr(Mo)) eutectic systems. Since it has been well established that the majority of eutectic alloys, such as Al-Cu, Al-Si and Al-Al{sub 3}Ni, display superplasticity under appropriate conditions, their enthusiasm for exploring whether the multiphase Ni-25Al-25Cr alloy, containing a ternary eutectic of {beta}Ni(Al,Cr) + {gamma}{prime}Ni{sub 3}(Al,Cr) is appropriate.