The influence of heat treatment processing on microstructure and mechanical properties of Ti–24Nb–4Zr–8Sn alloy by powder metallurgy

Abstract

Different heat treatments, including quenching and hot isostatic pressing, were conducted on the Ti–24Nb–4Zr–8Sn alloy fabricated by powder metallurgy, in order to improve its mechanical properties. As-sintered samples have high oxygen content over 3000 ppm, resulting in α phase precipitates and low ductility. But the mechanical properties can be improved by solution treatment at a suitable temperature and subsequent quenching. Although the treatment is only effective within a narrow temperature window ranging from 950 to 1000 °C, the treatment can completely eliminate the detrimental α phase and substantially improve the ductility of the alloy from 2% to 19.33%. In comparison, although the hot isostatic pressing can improve the density of the as-sintered alloy to nearly fully dense, it proves unable to remove the α phase from the material or improve its ductility alone.