Creep behavior and fracture mechanism of high Al/Nb-containing TiAl alloy

High Al content inhibits the formation of B2 phase, which improves creep resistance in high Al/Nb-containing TiAl alloys. In this work, the microstructure evolution and creep behavior of TiAl based alloy Ti-46Al-8Nb (at.%) with a high Al/Nb content, produced by the vacuum consumable electrode melting technology and the electromagnetic cold crucible melting technology, were studied. The microstructure of the Ti-46Al-8Nb alloy is composed of α2/γ phases arranged in layers with different orientations, which possesses smooth grain boundaries due to small-blocky segregation and irregular serrated grain boundaries caused by large-blocky segregation. Under conditions of 780–820 °C and 125–175 MPa for 200 h, it…