Effect of iron and nickel impurities on creep and tensile behaviour of Ti-24Al-20Nb-0.5Mo alloy

Creep properties of near α and α + β titanium alloys have been known to be strongly influenced by trace elements such as Fe and Ni. Effect of these elements on creep properties of Ti2AlNb base alloys is relatively unknown. This paper presents the effect of Fe and Ni content in a Ti2AlNb alloy: Ti-24Al-20Nb-0.5Mo. The Fe and Ni contents in the alloy have been varied by appropriate selection of raw materials. The results indicate that while Fe and Ni do not affect room temperature tensile properties, creep resistance is strongly degraded by increase in Fe and Ni content. 100 h creep strain, steady state creep rate and primary creep strain all are shown to improve with lowering of Fe and Ni.