Deformation Behavior of Ti-5.6Al-4.8Sn-2.0Zr-1.0Mo-0.35Si-0.85Nd Alloy in β/Quasi-β Forging Process

The hot deformation behavior of Ti-5.6Al-4.8Sn-2.0Zr-1.0Mo-0.35Si-0.85 Nd alloy in β/quasi-β forging process was studied using isothermal compression tests over temperature range from 1040 ℃ to 1100 ℃ and strain rates form 0.001 s~(-1)to 70 s~(-1)The results show that the flow stress and microstructure are sensitive to thermomechanical parameters.The processing maps based on the dynamic materials model at strain of 0.3 and 0.7 were established.The optimum deformation thermomechanical parameters at a strain of 0.7 have two regions that exhibit the peak of power dissipation efficiency.One is the region of 1062-1100 ℃ and 10~(-3)-10~(-1.5)s~(-1); and another which represents dynamic recrystallization is 1040-1045 ℃ and 10~(-1.8)-10~(-0.9)s~(-1)The instable region is located where the strain rate is larger than 1 s~(-1)which corresponds to the mechanical instability.