High temperature plastic deformation behavior of powder metallurgic TA15 titanium alloy

The hot deformation behaviors of P/M TA15 alloy in the temperature scope of 850~1050°C, with strain rates of 0.001~10 s-1 and maximum deformation of 60% were investigated using Gleeble-1500 thermal simulation test machine. The deformation activation energy of this alloy was calculated and the constitutive equation was obtained. The results show that the true stress of hot deformation of P/M TA15 alloy increases with decreasing deformation temperature and increasing strain rate. The deformation activation energy is 245.57 KJ&middotmol-1 in β phase region, which reveals that the main softening mechanism is dynamic recovery in β phase region. the deformation activation energy of (α+β) phase region is 945.69 KJ&middotmol-1, far higher than the diffusion activation energy of pure titanium, also higher than the deformation activation energy of conventional melting TA15 alloy, which shows that the hot deformation is associated with dynamic recrystallization.