Plastic deformation of pure copper in ultrasonic assisted micro-tensile test

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:785

Article

Kang, Jiarui¹  Liu, Xun¹  Xu, Mingjie² 

[1] Ohio State Univ, EJTC, 1248 Arthur Adams Dr, Columbus, OH 43221 USA

[2] Univ Calif Irvine, Irvine Mat Res Inst, Irvine, CA 92697 USA

关键词: Power ultrasonics;    Infrared imaging;    Flow stress reduction;    Digital image correlation;    EBSD;   

DOI  :  10.1016/j.msea.2020.139364

来源: Elsevier

【 摘 要 】

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.

【 授权许可】

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