Microstructure and Mechanical Properties of TaNbVTiAl_x Refractory High-Entropy Alloys

A series of TaNbVTiAl_x (x = 0, 0.2, 0.4, 0.6, 0.8, and 1.0) refractory high-entropy alloys (RHEAs) with high specific strength and reasonable plasticity were prepared using powder metallurgy (P/M) technology. This paper studied their microstructure and compression properties. The results show that all the TaNbVTiAl_x RHEAs exhibited a single BCC solid solution microstructure with no elemental segregation. The P/M TaNbVTiAl_x RHEAs showed excellent room-temperature specific strength (207.11 MPa*cm³/g) and high-temperature specific strength (88.37 MPa*cm³/g at 900 °C and 16.03 MPa*cm³/g at 1200 °C), with reasonable plasticity, suggesting that these RHEAs have potential to be applied at temperatures >1200 °C. The reasons for the excellent mechanical properties of P/M TaNbVTiAl_0.2 RHEA were the uniform microstructure and solid solution strengthening effect.