Drastically improved ductility of an Ir-base alloy by mixing Ir–Nb with Ni–Al

Abstract

The fcc/L1 2 coherent structure formed in the quaternary Ir–Nb–Ni–Al alloys. The ductility of quaternary Ir–Nb alloy was drastically improved by mixing with Ni–Al binary alloy. The two investigated alloys exhibited higher high-temperature 0.2% flow stress (e.g. above 1000 MPa at 1200 °C) and better ductility (≈20% both at room temperature and 1200 °C). An excellent balance of high-temperature strength and ductility was obtained. The improvement of ductility was attributed to change the fracture mode from intergranular to transgranular.