Authors：Yangen Li , Yujie Jia, Shihao Zhu, Yuta Ebi, Taisei Sugiyama, Takashi Yajima, Heting Liao, Hossan Rana, Yuji Sato, Shuhei Shinzato, Shigenobu Ogata

Affiliation：Osaka University

Abstract：The chemical ordering of CoNiCrFeMn and its effect on radiation resistance is analysed in this study via Monte Carlo (MC) annealing simulation and molecular dynamics (MD) radiation damage simulation. MC annealing at a lower temperature of 600 K forms an initial stage Cr-rich region in CoNiCrFeMn due to a strong chemical ordering-driven phase decomposition, whereas, annealing at a higher temperature of 1100 K forms a chemical short-range order (CSRO). MD radiation damage simulation shows that the Cr-rich region formed by 600 K annealing accelerates the aggregation and the evolution of defects, facilitating more dislocation loops formation. On the other hand, the CSRO structure formed by 1100 K annealing effectively delays the growth of defect number and tends to reduce the dislocation density and defect diffusion, suggesting better radiation resistance. However, the CSRO structure is destroyed by radiation, thus these advantages of CSRO will disappear in due time if CSRO cannot heal. Fortunately, since the CSRO can recover at working temperature of 1100 K, we speculate that under the working temperature of 1100 K and with a modest radiation damage rate, the advantages of CSRO can maintain for a long time. We finally discuss the condition of the CSRO preservation by proposing a CSRO radiation damage – diffusion healing competition model.

 

Publication related to your research:
（Journal paper）

• Li, Y., Du, J. P., Yu, P., Li, R., Shinzato, S., Peng, Q., & Ogata, S. (2022). Chemical ordering effect on the radiation resistance of a CoNiCrFeMn high-entropy alloy. Computational Materials Science, 214, 111764.