Microstructure and mechanical properties of TaNbVTiAlx refractory high-entropy alloys

Abstract

A series of TaNbVTiAlx (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 TaNbVTiAlx RHEAs exhibited a single BCC solid solution microstructure with no elemental segregation. The P/M TaNbVTiAlx 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 TaNbVTiAl0.2 RHEA were the uniform microstructure and solid solution strengthening effect.