Tensile Deformation Behavior of TC4 Titanium Alloy

High temperature tensile behaviors of TC4 titanium alloy from 800 to 960℃ at strain rates ranging from 0.01 to 10.00 s-1 were investigated by using Gleeble-1500D thermo-mechanical simulator. The constitutive equation of the maximum deformation resistance and pro-cessing maps for hot working were established. The in-situ tensile test of TC4 alloy was carried out by tensile equipment installed in scanning electron microscope (SEM). The evolution of crystal orientation and grain size of TC4 alloy before and after tensile deformation were analyzed by electron backs cattered diffraction (EBSD). The experimental results showed that the hot deformation activation energy Q of TC4 titanium alloy was 705.87 kJ•mol-1. The energy dissipation efficiency increased with the decrease of temperature and strain rate, and there was no instability zone. In the process of crack propagation, the holes firstly appeared in the grain boundary, and then small cracks formed and ultimately combined to form the main crack, which eventually led to the fracture of the specimen. The specimens fracture were intergranular and transgranular mode. The twinnings appeared during the tensile progress and the internal grains were stretched along the tensile direction. The disorder grains gradually paralleled to the <010> direction, which led to the formation of <010> texture. © Editorial Office of Chinese Journal of Rare Metals. All right reserved.