Tensile behavior and microstructure evolution of Mo-14 %Re alloy at room temperature and elevated temperatures

Abstract

The present work investigates the tensile deformation behavior and fracture mechanism of Mo-14 %Re alloy (MR14) at both room and high temperatures. The results show that the tensile strength of MR14 alloy is 613 MPa at room temperature and 260 MPa at 1000 °C. Moreover, the MR14 exhibits remarkable ductility, with elongation surpassing 60 % both at ambient temperature and elevated temperatures. As the temperature rises, dynamic recrystallization and the rotation of subgrains lead to the evolution of texture during fracture, which has not been reported hitherto. A high proportion of low-angle grain boundaries (LAGBs) facilitates the dislocation transfer, thereby preventing the nucleation of cracks caused by stress concentration. The strong texture, abundant substructure, movable edge dislocation and mixed dislocation on the bundle structures are the main toughening factors. Additionally, during the high-temperature tensile deformation process, the MR14 alloy maintains a single-phase structure without precipitation, demonstrating excellent thermal stability. These research findings hold profound significance for broadening the application scope of the MoRe alloy.