On the ductilization and the resistance to annealing-induced embrittlement of high-strength W–Re and nano-particle doped W-Re-ZrC alloys

Abstract

Ductilization and suppression of annealing-induced embrittlement have become the critical premises for various structural applications of high-strength tungsten materials but have yielded few practical advances. Here, we successfully fabricated W–Re and nano-particle doped W-Re-ZrC alloys with a combination of desirable ductility and a high tensile strength above 1.3 GPa by powder metallurgy plus hot swaging. Specifically, the W–Re and W-Re-ZrC alloys exhibit total elongations of 31.6% and 16.1%, respectively, at room temperature. Upon high-temperature annealing at 1600 °C, the W-Re-ZrC alloy still retains a high total elongation of 12.9% and a high tensile strength of over 1.3 GPa, unlike the W–Re alloy, which exhibits substantial losses of ductility and strength. Microstructure analysis reveals that a large amount of low-angle grain boundaries and high-density mobile dislocations are responsible for ductilization. Meanwhile, ZrC nano-particles stabilize low-angle grain boundaries and dislocation structures at elevated temperatures, suppressing annealing-induced embrittlement in the W-Re-ZrC alloy. The present work provides a promising methodology for manufacturing bulk high-strength tungsten materials with favorable room-temperature ductility and high resistance to catastrophic failure during long-term service.