Understanding the hot deformation behavior of Mo–42Re alloy: Insights from strain rate sensitivity, microstructure, and misorientation

Mo–42Re alloy, as a high-temperature structural and functional material, has broad application prospects in the nuclear industry. In this study, the hot deformation behavior of Mo–42Re alloy was systematically investigated using hot compression tests and electron backscatter diffraction (EBSD) techniques in the temperature range of 1200–1500 °C and strain rate range of 0.001–1 s⁻¹. The results showed that the flow stress of Mo–42Re alloy exhibited a strong dependence on temperature and strain rate. The strain rate sensitivity index (m-value) was high under the conditions of 1350–1450 °C and 0.001 s⁻¹. With increasing deformation temperature and decreasing strain rate, dynamic recrystallization (DRX) was significantly promoted, and the recrystallized volume fraction increased from 2.79% at 1200 °C/1 s⁻¹ to 20.3% at 1500 °C/0.001 s⁻¹. Meanwhile, the occurrence of and DRX effectively reduced the grain reference orientation deviation (GROD) gradients and kernel average misorientation (KAM) levels within the grains. This study revealed the mechanisms of microstructural evolution during hot deformation of Mo–42Re alloy, providing important guidance for optimizing its thermomechanical processing parameters.