Effect of Ti and Nb Contents on Microstructure and Mechanical Properties of HfZrVTaMoWTi<sub><i>x</i></sub>Nb<sub><i>y</i></sub> Refractory High‐Entropy Alloys
Hongwei Yao, Junwei Miao, Yongmiao Liu, Enyu Guo, H. Huang, Yiping Lu, Tongmin Wang, Tingju Li
Abstract
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 HfZrVTaMoWTi x Nb y 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 HfZrVTaMoWTi 2 Nb 2 RHEA without Laves precipitates exhibits a high yield strength of 1.7 GPa and a compressive strain of ∼30% at RT. Moreover, it retains a high systemic yield strength of 31 MPa cm 3 g −1 at 1200 °C, which is nearly three times that of HfZrTaTiNb and nearly equal to that of MoWTaNb, suggesting its potential applicability at elevated temperatures.