Microstructure evolution of S-TC4 titanium alloy blade preformed by cross wedge rolling

This paper proposed to use cross wedge rolling (CWR) to manufacture sintered TC4 (S-TC4) titanium alloy blade preform prepared by powder metallurgy technology. The hot uniaxial compression tests, CWR experiments, and numerical simulation were carried out to investigate the influence of forming parameters on microstructure evolution. The results showed that the pattern of stress-strain curve is typical featured of work hardening and dynamic softening, and the Arrhenius equation was determined to describe the high-temperature flow behavior of the studied S-TC4 alloy. In regard to microstructure evolution, the volume fraction of alpha phase f(alpha) increases and then decreases radially from inside to outside, and the lamellar alpha phase was equiaxialized by to the shear and torsion stress. And increasing the initial forming temperature T was not conducive to the preservation of the alpha phase, and both the volume fraction of alpha phase f(alpha) and average thickness of lamellar alpha phase l(alpha) are negatively correlated with the rolling speed n and area reduction phi. Moreover, the maximum initial forming temperature, rolling speed, and area reduction are 940 degrees C, 10 r/min, and 60%, respectively, in order to achieve the best match between strong plasticity and thermal.