Effect of Ti and Nb Contents on Microstructure and Mechanical Properties of HfZrVTaMoWTi x Nb y Refractory High‐Entropy Alloys

Refractory high-entropy alloys (RHEAs) with excellent high-temperature performance are attractive for high-temperature structural applications. However, many RHEAs suffer from high density and poor room temperature (RT) malleability. Herein, the effects of Ti and Nb contents on the phase equilibrium and mechanical properties of HfZrVTaMoWTixNby RHEAs are studied to achieve unique balanced properties in a wide temperature range. With the increase of Ti or Nb content, the Laves phase precipitation is suppressed and RT malleability is improved. Particularly, the HfZrVTaMoWTi2Nb2 RHEA without Laves precipitates exhibits a high yield strength of 1.7 GPa and a compressive strain of similar to 30% at RT. Moreover, it retains a high systemic yield strength of 31 MPa cm(3) g(-1) at 1200 degrees C, which is nearly three times that of HfZrTaTiNb and nearly equal to that of MoWTaNb, suggesting its potential applicability at elevated temperatures.