Applied Mathematics and Mechanics (English Edition) ›› 2022, Vol. 43 ›› Issue (2): 233-246.doi: https://doi.org/10.1007/s10483-022-2803-5

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Effects of grain boundary on irradiation-induced zero-dimensional defects in an irradiated copper

Jing PENG1, Shiyong CUI1, Yuanyuan TIAN1, Qihong FANG1, Jia LI1, P. K. LIAW2   

  1. 1. State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, College of Mechanical and Vehicle Engineering, Hunan University, Changsha 410082, China;
    2. Department of Materials Science and Engineering, The University of Tennessee, Knoxville, Tennessee 37996, U. S. A
  • Received:2021-08-04 Revised:2021-11-01 Published:2022-01-25
  • Contact: Jia LI, E-mail:lijia123@hnu.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Nos. 51871092 and 11772122) and the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (No. 51621004)

Abstract: Grain boundaries (GBs) can serve as efiective sinks for radiation-induced defects, thus notably influencing the service performance of materials. However, the efiect of GB structures on the zero-dimensional defects induced by irradiation has not been fully elucidated. Here, the evolution of cascade collision in the single-crystal (SC), bicrystalline (BC), and twinned crystalline (TC) copper is studied by atomic simulations during irradiation. The spatial distributions of vacancies and interstitials are closely related to the GB at a certain primary knock-on atom (PKA) energy. Compared with the TC, the BC displays a more obvious segregation of the interstitial atoms near GB, due to the characteristic of the greater interstitial binding energy. The evolution of Frenkel pairs is more sensitive to the change of the GB position in the BC. A more prominent defect annihilation rate is caused by the efiect of the GB than that of the twin boundary (TB). The marked secondary emission phenomenon has been observed in the BC, which promotes the formation of an inverted pagoda-like defect distribution. There are similar sub-conical defect distributions and microstructures induced by cascade collision in the TC and the SC. It has been found that the influence range of the GB is wider in the BC. Meanwhile, the average flow stress of the irradiated copper is quantitatively calculated by establishing a physical strengthening model. The contribution of vacancy to the average flow stress in the irradiated BC and TC is obvious than that in the SC, due to the formation of many vacancies. This study provides a theoretical basis for further understanding and customization of the metal-based equipment with good radiation resistance.

Key words: irradiation, cascade collision, grain boundary (GB), interstitial and vacancy, molecular dynamics (MD) simulation, physical strengthening model

2010 MSC Number: 

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