Effect of Ti content on microstructure and properties of TixZrVNb refractory high-entropy alloys

Abstract

This study aimed to investigate the microstructure and mechanical properties of TixZrVNb (x = 1, 1.5, 2) refractory high-entropy alloys at room and elevated temperatures. The TiZrVNb alloy consisted of the body-centered cubic (bcc) matrix with a small amount of V2Zr phase. The Ti1.5ZrVNb and Ti2ZrVNb alloys exhibited a single-phase bcc structure. At room temperature, the tensile ductility of the as-cast alloys increased from 3.5% to 12.3% with the increase in the Ti content. The TixZrVNb alloys exhibited high yield strength at 600°C, and the ultimate yield strength was more than 900 MPa. Softening occurred at 800°C, but the ultimate yield strength could still exceed 200 MPa. Moreover, the TixZrVNb alloys displayed low densities but high specific yield strengths (SYSs). The lowest density of TixZrVNb alloys was only 6.12 g/cm3, but the SYS could reach about 180 MPa·cm3·g−1, which is better than those of most reported high-entropy alloys (HEAs).