Plastic deformation of pure copper in ultrasonic assisted micro-tensile test
Plastic deformation of pure copper in ultrasonic assisted micro-tensile test
复制标题
超声辅助微拉伸试验中纯铜的塑性变形
DOI：
10.1016/j.msea.2020.139364
复制
发表时间：
2020-05-21
期刊：
影响因子：
6.4
通讯作者：
Xu, Mingjie
中科院分区：
文献类型：
--
作者：
Kang, Jiarui;Liu, Xun;Xu, Mingjie
采用比超声波长小一个数量级的试样规长微拉伸试验，从新的角度研究了超声振动对纯铜的软化作用。在此配置下，流变应力减小量随振动幅值线性增加，而流变应力减小量对0.06 ~ 1/s的应变速率不敏感。红外热成像与超声波振动相关的温升最小。原位数字图像相关（DIC）分析表明，在超声源附近应变局部化，而常规拉伸试验中应变分布均匀。光学显微组织表征表明，超声振动使变形铜中退火孪晶的面积分数从3.3%降低到1.8%。这可能是由于作为不可再生位错源的孪晶界之间的位错相互作用增强所致。电子背散射衍射（EBSD）结果表明，超声振动促进了晶粒的择优取向，减少了晶粒内部的取向错位。
The softening effect of ultrasonic vibration on pure copper is studied from a new perspective with micro-tensile tests, where the gauge length of the specimen is one order of magnitude smaller than the ultrasonic wavelength. With this configuration, the amount of flow stress reduction increases linearly with vibration amplitude whereas the flow stress reduction is insensitive to the studied strain rate ranging from 0.06/s to 1/s. Temperature rise associated with ultrasonic vibration is minimal from infrared thermal imaging. In situ digital image correlation (DIC) analysis shows strain localization near ultrasonic source whereas uniform strain distribution was observed during conventional tensile test. Optical microstructure characterization shows that area fraction of annealing twins in the deformed copper reduced from 3.3% to 1.8% with ultrasonic vibration. This is possibly attributed to enhanced interaction of dislocation between twin boundaries which act as non-regenerative dislocation source. Electron backscatter diffraction (EBSD) results show that ultrasonic vibration promotes preferential grain reorientation and reduces the misorientation within grains.