Acta Metallurgica Sinica (English Letters) ›› 2024, Vol. 37 ›› Issue (6): 1007-1018.DOI: 10.1007/s40195-024-01686-0

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Effects of Nitrogen Doping on Microstructures and Irradiation Resistance of Ti-Zr-Nb-V-Mo Refractory High-Entropy Alloy

Huanzhi Zhang1, Tianxin Li1, Qianqian Wang1, Zhenbo Zhu2, Hefei Huang2(), Yiping Lu1()   

  1. 1Engineering Research Center of High Entropy Alloy Materials (Liaoning Province), School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024, China
    2Shanghai Institute of Applied Physics, Chinese Academy of Sciences (CAS), Shanghai 201800, China
  • Received:2023-09-20 Revised:2023-12-20 Accepted:2023-12-26 Online:2024-06-10 Published:2024-04-09
  • Contact: Hefei Huang,huanghefei@sinap.ac.cn; Yiping Lu,luyiping@dlut.edu.cn

Abstract:

Interstitial strengthening with nitrogen (N) is one of the effective ways to improve the mechanical properties of HEAs, but the effects of N on the microstructures and mechanical properties of the irradiated HEAs have not been studied extensively. Here, the microstructures and mechanical properties of N-free and N-doped Ti2ZrNbV0.5Mo0.2 HEAs before and after He irradiation were investigated. The results showed that the solid solution strengthening caused by interstitial N improved the yield strength at room temperature and 1023 K without significantly reducing plasticity. N doping significantly promoted the growth, aggregation and wider spatial distribution of He bubbles by enhancing the mobility of He atoms/He-vacancy complexes, with the average size of He bubbles increasing from 10.4 nm in N-free HEA to 31.0 nm in N-doped HEA. In addition, N-doped HEA showed a much higher irradiation hardness increment and hardening fraction than N-free HEA. Contrary to conventional materials doped with N, the introduction of N into Ti2ZrNbV0.5Mo0.2 HEA had adverse effects on its resistance to He bubble growth and irradiation hardening. The results of this study indicated that N doping may not improve the irradiation resistance of HEAs.

Key words: High-entropy alloys, Nitrogen doping, Mechanical properties, Helium bubbles, Irradiation resistance