Creep behaviour of polycrystalline intermetallic Ti-53.4mol.%Al

摘要: Abstract Creep behaviour under a constant compressive stress of 80 to about 400 MPa was investigated at 950 1200 K on the polycrystalline intermetallic compound Ti-53.4mol.%Al, whose average grain diameter 42 μm. The shape creep curves depended significantly test conditions. At high stresses an extensive normal primary stage, followed by broad steady-state region, observed. extent stage diminished gradually with decreasing and, eventually, accelerating prevailed low stresses. and temperature dependence rates were greatly affected strain. exponent n apparent activation energy Q, which in early stages deformation, decreased increasing strain reached their plateau values 0.3 true strain: ∼ 4 aand Q 320 kJ mol −1 . A transition observed for minimum attained various depending condition. In high-stress region m 4.5 360 , whereas they almost twice these low-stress region.