Microstructure and Hardness of Laser Shocked Ultra-fine-grained Aluminum

Tiantian He1), Yi Xiong1,2), Zhiqiang Guo1), Lingfeng Zhang1), Fengzhang Ren1) and Alex A. Volinsky3) 1) School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471003, China 2) State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, China 3) Department of Mechanical Engineering, University of South Florida, Tampa FL 33620, USA

摘 要：Ultra-fine-grained commercial purity aluminum was produced by severe cold rolling, annealing and then strain- ing at ultra-high rate by a single pass laser shock. Resulted microstructure was investigated by transmission electron microscopy. Microhardness of annealed 0.6 μm ultra-fine grained aluminum increased by 67% from 24 to 40 HV. Many 0.3 μm sub-grains appeared at the shock wave center after a single pass laser shock, while high density dislocation networks were observed in some grains at the shock wave edges. Accordingly, microhardness at the impact center increased by 37.5% from 40 to 55 HV. From the impact center to the edge, microhardness decreased by 22% from 55 to 45 HV.

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