Abstract
TiAI intermetallic compounds containing 5-15at% Nb were prepared by sintering mixed powder compacts of TiH2, TiAl3 and NbAl3. The sintered compounds were further densified by HIPing at 1470K and 202MPa for 3.6ks without canning. Densifications by sintering and HIPing were examined as functions of Nb content, sintering temperature and sintered density. The microstructure of sintered and HIPed compounds was also examined. These experiments showed that both densifications by sintering and HIPing were diminished with increased Nb content. However, full densification was achieved when Nb contents were less than 10at% for 45at%Al compounds. HIPed density increased with increased sintered density, and became saturated when the relative sintered density exceeded 92% for Ti-45Al-10Nb(at%) compound. The microstructure varied with sintering temperature, and the lamellar structure increased with the rise of the sintering temperature. X-ray analyses on HIPed compounds exhibited B2-phase together with α2 and γ phases.
