Hot compression and microstructural evolution of Ti43Al5Nb0.03Y alloy

Thermo-mechanical processing parameters of Ti-43Al-5Nb-0.03Y (mole fraction, %) alloy are investigated by hot simulation tests at 1050~1250°C on Gleeble-1500D with a nominal deformation of 50% and a strain rate of 10^-1~10^-3 s^-1. The true strain-true stress curves have been obtained and the microstructures are observed. The results show that the microstructure consists of recrystallized grains and remained-lamellar when the compression temperature is lower than 1200°C, and of recrystallized grains at 1200°C. The major mechanism of plastic deformation is the slip deformation and twinning deformation, and the main softening mechanism is dynamic the recrystallization and dynamic recovery in the γ phase. The crack-free pancakes are obtained at a hot compressive temperature of 1200°C and a strain rate of 10^-3 s^-1.