High strength and tackling structural relaxation by sub-grains synergistic deformation in W-Re alloy

The reduction of strength and ductility due to structural relaxation induced by high-temperature annealing has greatly limited the application of tungsten-based alloys in structural functional applications. In this study, W-25(wt%)Re (WRE) alloy, which exhibits significant yielding behavior and tensile strength above 1.4 GPa at room temperature(RT), was successfully prepared by a combination of wet-chemical and rotary swaging process. After annealing at 1000 °C, WRE has an ultimate tensile strength (UTS) of 1253 MPa and total elongation (TE) of 9.8 % at 200 °C. Furthermore, following annealing at 1400 °C, WRE exhibits a UTS of 897 MPa at 500 °C, thereby demonstrating excellent resistance to annealing embrittlement and high-temperature strength. Microstructural analysis reveals that WRE retains a substantial number of fine subgrains and a considerable proportion of low-angle grain boundaries (LAGBs) following high-temperature annealing. The structural stability of WRE enables it to exhibit excellent high-temperature mechanical properties.