Crystal Orientation Effect on the Irradiation Mechanical Properties and Deformation Mechanism of a-Fe: Molecular Dynamic Simulations

X Huang and J Ding and K Song and SQ Lu and ZY Zhang and LS Wang, JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE (2022).

DOI: 10.1007/s11665-022-07730-3

The crystal orientation effect on the mechanical properties and micro- deformation behavior of single crystal iron (SC Fe) were revealed by molecular dynamics (MD) simulations. The results show that the surviving defects in the SC Fe models are 110 < 100 < 111, and only the vacancy and interstitial atomic clusters are formed in the 111 SC Fe model. Irradiation leads to the increase of elastic modulus owing to the annihilation of irradiation point defects. However, the non-annihilable irradiation clusters reduced the strength. The decrease of yield strain and yield strength of the 111 SC Fe model is significantly higher than those of 110 and 100 SC Fe models, exhibiting worse radiation damage resistance. This is due to the number and types of operation of slip systems in the 110 and 100 SC Fe after irradiation, which is caused by its poor inhibition of 111 crystal orientation on clusters under irradiation, being much lower than those in the 111 SC Fe. The yield strength of SC Fe increases with the increase of the number and length of 1/2 (111) and (100) dislocations, while the plasticity decreases with the increase of the falling gradient of dislocations after yield. The purpose is to provide theoretical guidance for the microstructure design and regulation of radiation-damage-resistant iron-based materials.

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