J. Mater. Sci. Technol. ›› 2022, Vol. 123: 70-77.DOI: 10.1016/j.jmst.2022.01.017

• Research Article • Previous Articles     Next Articles

Remarkably high fracture toughness of HfNbTaTiZr refractory high-entropy alloy

X.J. Fana,b, R.T. Qua,*(), Z.F. Zhanga,b,*()   

  1. aShi-changxu Innovation Center for Advanced Materials, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
    bNano Science and Technology Institute, University of Science and Technology of China, Suzhou 215132, China
  • Received:2021-12-13 Revised:2022-01-04 Accepted:2022-01-05 Published:2022-10-01 Online:2022-09-30
  • Contact: R.T. Qu,Z.F. Zhang
  • About author:zhfzhang@imr.ac.cn (Z.F. Zhang).
    *Northwestern Polytechnical University, Xi’an, China.E-mail addresses: rtqu@nwpu.edu.cn (R.T. Qu),

Abstract:

High-entropy alloys (HEAs) with face-centered cubic (FCC) phase such as CoCrFeMnNi or CoCrNi generally exhibit ultra-high fracture toughness but relatively low strength. In contrast, body-centered cubic (BCC) HEAs often display higher strengths, but the few reports on fracture toughness measurement demonstrate low toughness values. Here we show that the BCC HfNbTaTiZr refractory HEA, which possesses a combination of high strength, good tensile ductility and excellent high-temperature properties, also exhibits a remarkably high fracture toughness. By using the "single specimen" compliance method for J-integral measurement according to the ASTM E1820-17 standard, its fracture toughness KJIC was experimentally determined to be 210 MPa m1/2, which renders this HEA among the toughest metallic materials. The excellent damage tolerance makes the HEA promising for applications as high-temperature structural materials such as in aerospace field.

Key words: High-entropy alloys, BCC structure, Fracture toughness, J-integral