FeCoCrCuNi高熵合金裂纹及孔洞结构的力学与微观构象演化的分子动力学模拟研究  

Study on the mechanical performance and microstructure of FeCoCrCuNi high-entropy alloy with crack and void by molecular dynamics simulations

作　　者：董斌[1] 王雪梅[1] 朱子亮[1] DONG Bin;WANG Xue-Mei;ZHU Zi-Liang(Weifang University of Science and Technology,Weifang 262700,China)

机构地区：[1]潍坊科技学院,寿光262700

出　　处：《原子与分子物理学报》2020年第4期591-595,共5页Journal of Atomic and Molecular Physics

基　　金：潍坊科技学院博士启动金(2017BS06)。

摘　　要：本文采用分子动力学模拟研究了FeCoCrCuNi高熵合金裂纹和孔洞结构在不同轴向拉伸速率下的力学与微观结构演化机理.结果表明:应变速率越高FeCoCrCuNi裂纹结构对应更高的过冲应变和过冲应力,其主要原因是高拉伸速率会导致高强度的BCC结构及孪晶结构的生成,而BCC结构及孪晶结构的产生进而会抑制应力的下降,通过应力-应变曲线,可知FeCoCrCuNi裂纹模型在轴向应力作用下表现为塑性形变.对于不同尺寸的孔洞FeCoCrCuNi裂纹模型的应力结构分析,可以得出:孔洞尺寸越大,FeCoCrCuNi裂纹结构对应的过冲应变和过冲应力越小,其主要原因是大尺寸的孔洞造成孔洞之间产生裂纹的,进而会影响这个材料的屈服应变和屈服强度.Molecular dynamics(MD)simulations have used to study the mechanical performance and microstructure of FeCoCrCuNi high-entropy alloy with crack and void.The MD simulation results show that higher uniaxial stretched rate corresponds to higher overshoot stress and strain.This is due to the generation of BCC and twin crystal structure in FeCoCrCuNi model with high stretched rate.And the BCC and twin crystal structures will slow down the decrease of the stress.Thus,FeCoCrCuNi is plastic deformation under uniaxial stretched deformation.For voided-FeCoCrCuNi high-entropy alloy,the MD results shown that the values of the overshoot stress and strain decrease with increasing of the size of void.This is due to the generation of the crack between the voids for FeCoCrCuNi high-entropy alloy.

关 键 词：FeCoCrCuNi高熵合金 裂纹 孔洞 轴向拉伸 

分 类 号：TG111.91[金属学及工艺—物理冶金]