缺陷预熔化现象的晶体相场模拟  

Phase field crystal Simulation of Defect Pre-melting Phenomenon

作　　者：黄礼琳[1,2] 邓芊芊[1] 卢昱江 罗志荣[2] 高英俊[1] HUANG Lilin;DENG Qianqian;LU Yujiang;LUO Zhirong;GAO Yingjun(Guangxi Key Laboratory of Novel Energy Materials of College and University,College of Physics Science and Engineering,Guangxi University,Nanning,Guangxi530004,China;Institute of Physics Science and Engineering Technology,Yulin Normal University,Yulin,Guangxi537000,China)

机构地区：[1]广西大学物理科学与工程技术学院,广西高校新能源重点实验室,广西南宁530004 [2]玉林师范学院物理科学与工程技术学院,广西玉林537000

出　　处：《广西科学院学报》2017年第4期234-239,共6页Journal of Guangxi Academy of Sciences

基　　金：国家自然科学基金项目(51161003,51561031);广西自然科学基金重点项目(2012GXNSFDA053001)资助

摘　　要：【目的】研究外应变作用下BCC晶体中晶界和位错的预熔化现象,揭示晶界预熔化的机理。【方法】构建包含外力场与晶格原子密度耦合作用项的三维体系自由能函数,并建立以温度为主要参数的晶体相场模型,模拟三维情况下某一平面的晶界和位错的预熔现象。【结果】随着温度的升高,位错熔解的区域不断扩大,在接近熔点温度时晶界处的位错首先诱发晶界出现预熔化现象;当熔解趋于稳定后,在应力作用下,开始出现位错滑移现象,同一水平直线上的一组位错对相互靠近,最终湮没变为一个完整晶界。【结论】体系的温度影响并决定位错的熔解。体系温度越高,位错处的熔解就越容易进行。【Objective】The premelting phenomenon of grain boundaries and dislocations in BCC crystals under external strain is investigated to reveal the mechanism of premelting in grain boundaries.【Methods】The free energy function of the three dimensional system is constructed,which includes the coupling of external force field and lattice atom density.A phase field crystal model with temperature as the main parameter is established to simulate the premelting of grain boundaries and dislocations in a certain plane under threedimensional conditions.【Results】With the increase of temperature,the area of dislocation melting continues to expand,near the melting point temperature,the dislocations at the grain boundaries first induce the phenomenon of premelting at the grain boundaries.When the melting tends to stabilize,the phenomenon of dislocation sliding begins to appear under the action of stress,a set of dislocations on the same horizontal straight line approaches each other and eventually annihilates into a complete grain boundary.【Conclusion】The temperature of the system affects and determines the melting of the dislocations.The higher the system temperature is,the easier it is to melt at the dislocations.

关 键 词：缺陷 预熔化 晶体相场模型 

分 类 号：TG111.2[金属学及工艺—物理冶金]