Hot deformation behavior of nanostructural oxide dispersion-strengthened (ODS) Mo alloy

The hot deformation behavior of nanostructural oxide dispersion-strengthened (ODS) Mo alloy was investigated in the temperature range of 1200–1500 °C and strain rate range of 0.001–1 s⁻¹ with a constant strain of 0.50 by analyzing constitutive equations, hot processing maps, and microstructure evolution. The results show that the flow behavior is greatly affected by the deformation temperatures and strain rates, exhibiting typical hardening, softening, and steady stages. The constitutive equation is established, which can predict the flow stress precisely. The stress exponent n and the apparent activation energy Q are estimated to be 5.44 and 384.26 kJ·mol⁻¹, respectively, revealing that the deformation mechanism is dominated by the dislocation climb. Furthermore, the hot processing maps of ODS Mo alloy are developed based on the dynamic materials model, presenting two stability zones of 1350–1450 °C/0.001 s⁻¹ and 1450–1500 °C/0.1–1 s⁻¹. By observing microstructures, dynamic recovery and dynamic recrystallization occur in the stability zone 1500 °C/1 s⁻¹, and the mechanism of the stability zone 1400 °C/0.001 s⁻¹ is dominated by dynamic recovery and grain growth.