Fe33Ni33Cr合金中位错与位错环相互作用的分子动力学研究  

Investigation of Interactions between Dislocation and Dislocation Loops in Fe33Ni33Cr Alloy by Molecular Dynamics Simulation

作　　者：龙开泓 王东杰[1] 黄楚天 贾丽霞[1] 贺新福[1] 豆艳坤[1] LONG Kaihong;WANG Dongjie;HUANG Chutian;JIA Lixia;HE Xinfu;DOU Yankun(Department of Reactor Engineering Technology,China Institute of Atomic Energy,Beijing 102413,China)

机构地区：[1]中国原子能科学研究院反应堆工程技术研究所,北京102413

出　　处：《原子能科学技术》2024年第8期1662-1670,共9页Atomic Energy Science and Technology

基　　金：稳定基础支持项目(219306);中国原子能科学研究院院长基金(219256)。

摘　　要：为了进一步完善FeNiCr合金辐照硬化理论,本文利用分子动力学方法研究了等比多主元固溶体Fe33Ni33Cr合金中1/2<110>{111}刃型位错与1/3[111]弗兰克(Frank)位错环的相互作用机制及其影响因素。结果表明,在选取的3种典型温度(300、600、900 K)中,高温下位错环对位错运动的阻碍作用降低。其原因除了温度升高引起的原子热振动加剧促进位错运动外,还有300 K和600 K下位错与位错环相互作用导致Frank位错环间层错消失转变为完美环,进一步增加了位错环对位错的钉扎作用。此外,研究了位错环尺寸对位错滑移的影响效果。当位错环直径分别为2、4、6 nm时,位错环尺寸的增大使得位错与位错环相互作用面积增加,最终导致位错环对位错运动阻碍能力增强。值得注意的是,在位错环尺寸为2 nm和4 nm时,位错与位错环相互作用生成超割阶,新结构的产生增加了位错在基体中自由滑移时受到的阻力。The FeNiCr alloys hold application potential in advanced reactors,however,irradiation hardening severely impacts their safety during service.To further enhance the irradiation hardening theory of the FeNiCr alloys,the interaction mechanism between 1/2<110>{111}edge dislocation and 1/3 Frank dislocation loops in the equiproportional multi-principal solid solution Fe33Ni33Cr alloy and the influencing factors were investigated through the molecular dynamics(MD)simulations.Based on the model proposed by Osetsky and Bacon,a face-centered cubic cell with the x,y,and z axes of,,and was constructed with Fe33Ni33Cr as the matrix,and dislocation and dislocation loop were inserted into the cell.By varying the diameter of the dislocation loops and the temperature of the system,the diagram of the interactions and the stress-strain curves were obtained through MD simulation,and the influences of the size of the loops and temperature on the interaction process between the dislocation and dislocation loops were studied.The results indicate that the multi-principal component effect in the Fe33Ni33Cr alloy leads to stress fluctuations during dislocation slip,and the presence of the dislocation loops can cause the dislocation to have a significant stress peak during its slip process,that is,it has a remarkable hindering effect on the dislocation movement,thereby contributing to the irradiation hardening.At the three typical temperatures(300,600,and 900 K),the critical shear stress of the interaction between the dislocation and dislocation loops is lower at high temperatures than at low temperatures.The reason is that the atomic thermal vibration caused by the temperature increase promotes dislocation motion,and the structural change during the reaction between dislocation and dislocation loops also has a considerable influence on the stress.The interaction between the dislocation and the dislocation loops at 300 K and 600 K is unfault mechanism.In the interaction process,the stacking fault in the Frank dislocation loop disappears a

关 键 词：多主元固溶体合金 分子动力学 刃型位错 位错环 

分 类 号：TL341[核科学技术—核技术及应用]