BCC-Fe中螺位错与[010]间隙位错环相互作用分子动力学模拟  

Molecular Dynamics Simulation on Interaction between Screw Dislocation and[010]Interstitial Dislocation Loop in BCC-Fe

作　　者：王瑾 贺新福[1] 曹晗 王东杰[1] 豆艳坤[1] 杨文[1] WANG Jin;HE Xinfu;CAO Han;WANG Dongjie;DOU Yankun;YANG Wen(Division of Reactor Engineering Technology Research,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》2021年第7期1210-1218,共9页Atomic Energy Science and Technology

基　　金：国家自然科学基金(U1867217);国家重点研发计划(2018YFE0308104)。

摘　　要：本文利用分子动力学方法对BCC-Fe中螺位错与[010]间隙位错环的相互作用机制进行了模拟,研究结果表明,螺位错在不同温度下滑移靠近不同尺寸位错环时,它们之间的相互作用机制不同。当位错环尺寸为1.5 nm时,位错环在2 K下稳定存在,螺位错在剪切应力作用下滑移通过它,并与之位错反应生成[111]位错环,临界剪切应力明显增加;随温度升高到300 K和600 K,[010]位错环因稳定性降低会转变为[111]位错环,该位错环与螺位错反应可生成[010]位错片段,对螺位错阻碍作用逐渐变弱,临界剪切应力增量逐渐降低;随温度进一步升高到823 K,螺位错易交滑移,其与位错环始终无接触,因此无阻碍作用。当位错环尺寸增大到4 nm时,[010]位错环稳定性增加,300~823 K下位错环对螺位错滑移阻碍作用也明显增加。The interaction mechanism between screw dislocation and[010]interstitial dislocation loop in BCC-Fe was carried out by molecular dynamics(MD)simulation.It is found that their interaction mechanism is different when screw dislocation slips close to different sizes of dislocation loop at different temperatures.When the size of dislocation loop is 1.5 nm,[010]dislocation loop is stable at 2 K,screw dislocation can slide and pass through it,then react with it to form a 1/2 [111]dislocation loop,and the critical shear stress increases significantly.With the temperature increasing to 300 K and 600 K,[010]dislocation loop is unstable,and it can transform into a 1/2 [111]dislocation loop.The[010]dislocation fragment can be generated by the reaction of the new 1/2[111]dislocation loop with screw dislocation,which weakens the hindering effect on screw dislocation slip and decreases the critical shear stress increment.With the temperature further increasing to 823 K,screw dislocation is easy to cross slip and has no contact with the dislocation loop during the whole shear process.Therefore,there is no hindrance.When the size of dislocation loop increases to 4 nm,the stability of[010]dislocation loop increases,and the hindering effect of dislocation loop on screw dislocation slip also increases from 300 K to 823 K.

关 键 词：BCC-Fe 螺位错 温度 位错环尺寸 分子动力学 

分 类 号：TL341[核科学技术—核技术及应用]