基于二维离散位错动力学的双位错与沉淀相交互作用建模及性能预测  

Modeling of interaction between double-dislocation and precipitates based on two-dimensional discrete dislocation dynamics and performance prediction

作　　者：金浩[1] 赵刚[1] 刘娟[1] 章海明[1] 隋大山[1] 崔振山[1] JIN Hao;ZHAO Gang;LIU Juan;ZHANG Hai-ming;SUI Da-shan;CUI Zhen-shan(Institute of Forming Technology&Equipment,Shanghai Jiao Tong University,Shanghai 200030,China)

机构地区：[1]上海交通大学塑性成形技术与装备研究院

出　　处：《塑性工程学报》2019年第6期168-175,共8页Journal of Plasticity Engineering

基　　金：国家自然科学基金资助项目(51635005;51375306)

摘　　要：基于二维离散位错动力学方法,以含有L12型长程有序γ’沉淀相的镍基合金为研究对象,建立了双位错运动模型,模拟了位错与沉淀相的交互作用。模型中,位错的运动取决于滑移面上位错点的局部受力平衡,位错的受力考虑了双位错间的相互作用和位错自身的作用力。分析了沉淀相体积分数、平均半径以及反向畴界能对材料临界分切应力的影响。结果表明:在欠时效状态下,材料的临界分切应力随着γ’沉淀相的平均半径、反向畴界能、体积分数增大而增大,其中平均半径影响较小,反向畴界能的影响很大,当体积分数增大到一定程度,临界分切应力增长趋于平缓。相比于单位错模型,模拟结果与实验的数据更接近。Based on two-dimensional discrete dislocation dynamic(2D-DDD),a double-dislocation motion model was established for Nibased alloy with L12 long-range orderedγ'precipitates,and the interaction between dislocation and precipitate was simulated.In this model,the motion of dislocation depended on the local force balance of dislocation points at corresponding gliding plane,and for the force on dislocation,the interaction between double dislocations and the force acting on the dislocations themselves were taken into account.The effects of the volume fraction,average radius of precipitate,and antiphase boundary(APB)energy on material critical resolved shear stress(CRSS)were analyzed.The results indicate that the value of CRSS increases with the increase of average radius,APB energy and volume fraction ofγ'precipitate at under-aging state;the influence of average radius ofγ'precipitate is small and the influence of APB energy is great;when the volume fraction ofγ'precipitates increases to a certain degree,the CRSS tends to be a steady state.The simulation results obtained by the double-dislocation model are closer to the experimental data than those by single-dislocation model.

关 键 词：临界分切应力 二维离散位错动力学 双位错 γ’沉淀相 

分 类 号：TG142.1[一般工业技术—材料科学与工程] TG113[金属学及工艺—金属材料]