J. Mater. Sci. Technol. ›› 2022, Vol. 123: 191-200.DOI: 10.1016/j.jmst.2022.01.025

• Research Article • Previous Articles     Next Articles

Enhanced high-temperature strength of HfNbTaTiZrV refractory high-entropy alloy via Al2O3 reinforcement

Bingjie Wanga, Qianqian Wanga,b, Nan Luc, Xiubing Liangc,*(), Baolong Shena,*()   

  1. aSchool of Materials Science and Engineering, Jiangsu Key Laboratory for Advanced Metallic Materials, Southeast University, Nanjing 211189, China
    bSchool of Materials Science and Engineering, Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology, Nanjing Institute of Technology, Nanjing 211167, China
    cDefense Innovation Institute, Academy of Military Science, Beijing 100071, China
  • Received:2021-11-10 Revised:2022-01-17 Accepted:2022-01-20 Published:2022-10-01 Online:2022-09-30
  • Contact: Xiubing Liang,Baolong Shen
  • About author:blshen@seu.edu.cn (B. Shen).
    *E-mail addresses: liangxb_d@163.com (X. Liang),

Abstract:

Novel composites of HfNbTaTiZrV refractory high-entropy alloy (RHEA) reinforced with 0-4 vol.% Al2O3 particles have been synthesized by vacuum arc melting. The microstructure evolution, compressive mechanical properties at room and elevated temperatures, as well as strengthening mechanism of the composites were analyzed. The HfNbTaTiZrV RHEA reinforced with 4 vol.% Al2O3 displayed excellent phase stability at elevated temperatures. A superior compressive yield strength of 2700 MPa at room temperature, 1392 MPa at 800 °C, and 693 MPa at 1000 °C was obtained for this composite. The improved yield strength resulted from multiple strengthening mechanisms caused by Al2O3 addition, including solution strengthening, interstitial strengthening, grain boundary strengthening, and dispersion strengthening. Besides, the effects of interstitial strengthening increased with temperature and was the main strengthening mechanism at elevated temperatures. These findings not only promote the development of oxide-reinforced RHEAs for challenging engineering applications but also provide guidelines for the design of light refractory materials with multiple strengthening mechanisms.

Key words: Al2O3-reinforcement, HfNbTaTiZrV, Refractory high-entropy alloy, Interstitial strengthening