Constitutive Equation and Processing Parameter Sensitivities for Hot Deformation of Pure Mo

The hot deformation behavior of powder metallurgy pure Mo is investigated by analyzing constitutive equations, the strain rate sensitivity (SRS) and temperature sensitivity (TS) coefficient distribution maps, and microstructure evolution. Hot compression tests are conducted at different temperatures and strain rates range of 1000-1300 degrees C and 0.005-1 s-1, with a constant true strain of 0.5. The results show that the flow behavior is greatly affected by deformation temperatures and strain rates, exhibiting typical hardening and softening stages. The constitutive equation is established, and the apparent activation energy Q is estimated as 456 kJ/mol. Furthermore, the SRS coefficient increases with increasing deformation temperature and decreasing strain rate, while the TS coefficient increases with increasing deformation temperature at high strain rates. Together with microstructure evolution, it shows an optimum hot working parameter of 1300 degrees C/0.005 s-1.