Ta W Refractory Alloys with High Strength at 2000°C

Advanced structural alloys that can withstand exceedingly high operating temperatures are in high demand. The high-temperature strength of these alloys needs to be above a certain level, above and beyond what can be offered by currently available alloys, while still having adequate room-temperature ductility to allow sufficient forming ability. In this study, Ta-W refractory alloys with W content ranging from 10% to 50% (atomic fraction) are prepared using arc-melting. All the Ta-W alloys are single-phase solid solutions with a bcc structure, and their average grain size decreases with increasing W content. Uniaxial compression tests are performed at both 25 degrees C and 2000 degrees C for the Ta-W alloys. The results suggest that the compressive yield strength of the Ta-W alloys increases with the W concentration at both temperatures, and they exhibit excellent compressive strength at high temperatures. In particular, the strength of the Ta-20%W alloy could reach as high as 236 MPa at 2000 degrees C, a benchmark never reported for known alloys, while offering room-temperature shaping capability with a compressive strain over 40% at 25 degrees C. A recent model based on screw dislocation activities in bcc concentrated solutions yields a reasonable prediction for the yield strength measured at both temperatures. Such Ta-W refractory alloys have the potential for load -bearing applications at extremely high temperatures.

Automated summary

There is high demand for advanced structural alloys that can withstand extremely high operating temperatures. In this study, Ta-W refractory alloys with varying tungsten content were prepared and tested for their compressive strength at different temperatures. The results showed that the compressive yield strength of the alloys increased with the tungsten concentration, especially at 2000 degrees C, where the Ta-20%W alloy exhibited a record-breaking strength of 236 MPa. This alloy also had good room-temperature shaping capability, making it a potential candidate for load-bearing applications at extremely high temperatures.