Thermal stability of Ti-44Al-4Nb-4Hf-0.2Si-1B alloy

► 1/3 less α2 dissolved and 1/4 less B2 + ω formed in the alloy after 10,000-h exposure. ► The exposure-induced embrittlement was less severe in the alloy. ► The mechanism is related to a changed partitioning behaviour due to Nb + Hf addition. ► Tensile strengths remain unchanged and fatigue limit increased for alloy 4Nb-4Hf.