Competitive effects of rolling strain and rhenium alloying on the ductile-to-brittle transition of tungsten

Re alloying is considered to improve W toughness by lowering lattice Peierls stress, yet whether its microstructural benefits deliver macroscopic toughening under pre-strained conditions remains unclear. Here, we employ W-xRe (x = 0, 3, 5, 10%) alloys as model materials and subject them to different degrees of rolling strain (ε_r=0.2 and 0.667) to figure out the competitive effects of Re solutes and rolling strain on the DBTT of W. As the Re concentration increases, the DBTT of W-Re alloys gradually elevated from 350 °C to 550 °C due to the solute hardening effect. Conversely, the DBTT of W-Re alloys decrease to around 300 °C with increasing strain. The competitive effects of Re alloying and rolling strain on DBT of W are discussed based on the characteristics of slip traces and cracking morphologies. Our findings indicate that pre-straining is more effective than Re alloying to reduce the DBTT of W.