分子动力学研究Cu析出相对BCC-Fe∑3{111}晶界拉伸性能的影响

Molecular Dynamics Study of Cu Precipitation Relative BCC-Fe∑3{111}Grain Boundary Tensile Properties

采用分子动力学方法模拟计算了BCC-Fe∑3{111}晶界处Cu析出相尺寸(直径:1.0、1.5和2.0 nm)及体系温度变化(1~600 K)对晶体拉伸性能的影响。利用OVITO可视化软件进行数据可视化处理,并采用Wigner-seitz Defect Analysis方法对拉伸过程晶体点缺陷演化规律进行分析。结果表明,∑3{111}晶界处存在Cu析出相时,拉伸过程中Cu析出相内部会首先产生空位缺陷导致晶体断裂强度降低,且Cu析出相尺寸越大,晶体断裂强度越低。当晶界处Cu析出相尺寸不变时,随着体系温度升高,晶体的断裂强度随之降低,并且晶界处Cu析出相尺寸越小时温度升高对晶体断裂强度的降低作用越大。

The BCC-Fe∑3{111}grain boundary in Cu precipitation phase size(diameter:1.0,1.5 and 2.0 nm)and the system temperature change(1—600 K)on the tensile properties of the crystal is calculated by using molecular dynamics simulation method.OVITO visualization software was used for data visualization and wigner-seitz defect analysis method was used to analyze the defect evolution law of crystal points in the tensile process.Results show that∑3{111}grain boundary in Cu precipitated phase,the stretching process of Cu precipitation phase within the first vacancy defects lead to crystal fracture strength is reduced,and Cu precipitation phase size is larger,the crystal fracture strength is lower.When the size of Cu precipitates at grain boundary remains unchanged,the fracture strength of crystals decreases as the system temperature increases,and the smaller the size of Cu precipitates at grain boundary,the greater the effect of temperature increases on the crystal fracture strength decreases.