Grain boundary effects on spall behavior of high purity copper cylinder under sweeping detonation  

滑移爆轰冲击下晶界对柱壳状高纯铜层裂行为的影响

作　　者：YANG Yang HUANG Jun-yi WANG Hai-min CHEN Ji-xiong GUO Zhao-liang 杨扬;黄均毅;王海民;陈冀雄;郭昭亮(School of Materials Science and Engineering,Central South University,Changsha 410083,China;Institute of Fluid Physics,China Academy of Engineering Physics,Mianyang 621900,China;Key Laboratory of Nonferrous Metals Materials Science and Engineering of Ministry of Education,Central South University,Changsha 410083,China)

机构地区：[1]School of Materials Science and Engineering,Central South University,Changsha 410083,China [2]Institute of Fluid Physics,China Academy of Engineering Physics,Mianyang 621900,China [3]Key Laboratory of Nonferrous Metals Materials Science and Engineering of Ministry of Education,Central South University,Changsha 410083,China

出　　处：《Journal of Central South University》2022年第4期1107-1117,共11页中南大学学报（英文版）

基　　金：Projects(51871243,51574290)supported by the National Natural Science Foundation of China;Project(2019JJ40381)supported by the Natural Science Foundation of Hunan Province,China;Project supported by the Guangdong-Hong Kong-Macao Joint Laboratory for Neutron Scattering Science and Technology,China。

摘　　要：A series of sweeping detonation experiments were conducted to study the grain boundary effects during the primary spallation of high-purity copper cylinder.The free surface velocity profile of the shocked samples was measured by Doppler pins systems.The soft-recovered samples were characterized by optical and electron backscatter diffraction microscopy,and the effects of microstructures like grain boundaries,and crystal orientation on spall behavior were investigated.The results indicated that the critical stress of deformation twinning in cylindrical copper increased.The nucleation sites of spallation damage were determined by the joint influence of the grain orientation(Taylor factor)and the angle between grain boundaries and radial impact-stress direction.Voids were prone to nucleating at the grain boundaries perpendicular to the radial impact-stress direction.Nevertheless,the number of voids nucleated at boundaries was relatively different from the results obtained from the plate impact experiment and plate sweeping detonation experiment,which is a result of the curvature that existed in the cylindrical copper and the obliquity of the impact-stress direction during sweeping detonation loading.本文通过对柱壳状高纯铜进行一系列的滑移爆轰实验,研究了晶界对柱壳状高纯铜初期层裂过程的影响。利用多普勒探针系统(DPS)测量了受冲击样品的自由表面速度曲线。通过光学显微镜和电子背散射衍射(EBSD)技术对软回收的样品进行了表征,具体研究了微观结构如晶界、晶体取向等对层裂行为的影响。结果表明,柱壳状高纯铜在层裂过程中形变孪晶临界应力会增大;晶粒取向(TF值)和晶界与径向冲击应力方向的夹角共同决定了层裂损伤的形核位置;孔洞容易在垂直于径向冲击应力方向的晶界处形核。与之前平板飞片冲击实验和平板滑移爆轰实验的结果相比,本滑移爆轰实验中高纯铜在晶界处形核的孔洞数量存在较大差异,这是由柱壳状试样自身的几何曲率和滑移爆轰加载过程中冲击应力方向与晶界之间的倾角引起的。

关 键 词：sweeping detonation high purity copper cylinder SPALLATION microstructure electron backscatter diffraction 

分 类 号：O346.1[理学—固体力学] TG146.11[理学—力学]