Microstructure and mechanical properties of a PM TiAl-W alloy processed by hot isostatic pressing

A PM Ti-48at.%Al-2at.%W alloy was fully consolidated under two HIp conditions. A HIP cycle with a peak temperature of 1360 °C produced a fine-grained duplex microstructure. Increasing the peak temperature to 1395 °C developed a coarse-grained fully lamellar microstructure. The former yielded better room-temperature tensile strength and ductility, while the latter showed slightly higher ultimate tensile strength at 850 °C and superior creep resistance at 760 °C, 276 MPa. The fracture surfaces and deformation substructures of the tested specimens were analyzed and correlated with their mechanical behaviour. The effect of HIP conditions on the microstructures and the microstructure-property relationships is discussed.