High Temperature Tensile Properties and Brittle-to-Ductile Transition of Directionally Solidified NiAl-15Cr Alloy

The microstructure,high temperature tensile properties and brittle-to-ductile transition condition of directionally solidified NiAl-15Cr alloy had been investigated.The results show that the microstructure was dendritic shape.The dendrite arm was β-NiAl phase,γ phase was in interdendritic region and transient layer was γ′ phase.The alloy showed good plasticity and strength at high temperatures and superplasticity-like deformation behavior at 1 323 K.And it had obvious brittle-to-ductile transition temperature(BDTT),which was 873 K as the strain rate was 1.11×10-4 s-1.When the initial strain rate increased by two order of magnitude,the BDTT increased by approximate 150 K.