1. Microstructure evolution and electroplasticity in Ti64 subjected to electropulsing-assisted laser shock peening.
- Author
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Zhang, Hao, Ren, Zhencheng, Liu, Jun, Zhao, Jingyi, Liu, Zhikun, Lin, Dong, Zhang, Ruixia, Graber, Matthew J., Thomas, Nicholas K., Kerek, Zachary D., Wang, Guo-Xiang, Dong, Yalin, and Ye, Chang
- Subjects
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LASER peening , *MATERIAL plasticity , *MICROSTRUCTURE , *SURFACE preparation , *SURFACE finishing - Abstract
In this study, an innovative surface treatment method, electropulsing assisted laser shock peening (EP-LSP), was used to process Ti64 samples. In EP-LSP, metallic samples are subjected to simultaneous high strain rate plastic deformation and high-frequency (100–500 Hz) short-duration (100 μs) pulsed electric current. The effects of EP-LSP on surface finish, microstructure, and micro-hardness of Ti64 alloy were investigated and compared with continuous current assisted LSP (CC-LSP) having the same bulk heating effect. It was observed that EP-LSP produced higher surface hardness and deeper hardened layer, both of which indicate greater plastic deformation. Tensile tests were carried out to evaluate the plasticity of Ti64 subjected to pulsed current and continuous current with the same bulk heating effect. It was observed that pulsed current can more effectively decrease the flow stress and thus resulted in greater plasticity in Ti64 compared with continuous current, even though the bulk heating effect was the same. In addition, the higher the peak current density, the more effective the flow stress reduction. As a result, pulsed current can more effectively improve the effectiveness of LSP treatment, as manifested by higher surface hardness and deeper plastic deformation layer. It is believed that an athermal effect in addition to the thermal effect related to pulsed current exists in EP-LSP. • EP-LSP results in higher surface hardness and deeper hardened layer compared with LSP. • Higher peak current density leads to more effective EP-LSP treatment. • Pulsed current is more effective in improving the plasticity of Ti64 compared with continuous current. • An athermal effect that cannot be explained by resistive heating exists in EP-LSP. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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