Effect of Hf, B and Zr on the Ductility of Ni3(Al,Fe) Intermetallic Compounds

Abstract

Effects of hafnium, boron and zirconium on the ductility of Ni3(Al, Fe) intermetallic compounds were studied using tensile test and SIMS analysis. Ni3(Al, Fe) alloy with 0.1 at.% Hf, 0.05 at.% B and 0.1 at.% Zr additions showed maximum elongations of about 30% at 300K, 10% at 300K and 14% at 473K, respectively. The fracture mode of the alloy without the additive was the mixture of intergranular and transgranular fractures, but the addition of Hf, Zr or B changed the fracture mode to transgranular only. SIMS analysis showed that the beneficial effects of Hf, Zr or B segregation on the grain boundary strength are consistent with the grain boundary cohesion theory.