Flow Behavior and Processing Map for Hot Deformation of W-3Re-5HfC Alloy

The hot deformation behavior of W-3Re-5HfC alloy was investigated by compression at the temperature range of 1200–1500°C and the strain rate range of 0.001–1 s⁻¹ on a Gleeble-1500D thermal simulator. The results show that the flow stress increases with increasing strain rates or decreasing deformation temperature. The deformation temperature and strain rates affect the flow behavior, exhibiting typical hardening, softening and steady stages. The constitutive equation was established based on the experimental data. The apparent activation energy Q is estimated to be 361 kJ mol⁻¹. Hot processing maps have been constructed at the true strain of 0.1 and 0.6. Moreover, the areas of 1200–1300°C/0.001–0.1 s⁻¹ and 1400–1500°C/0.1–1 s⁻¹ are identified as instability area. Dynamic recovery and dynamic recrystallization occur in the stable area 1500°C/1 s⁻¹, and the mechanism of the stable area is dominated by dynamic recovery and grain growth.