Effects of laser shock processing and strain rate on tensile property of LY2 aluminum alloy

The effects of laser shock processing (LSP) on tensile property of LY2 aluminum (Al) alloy were investigated, and strain rate sensitivity of the untreated and treated samples by LSP was studied at the strain rates ranging from 0.00001 s−1 to 0.1 s−1. In both conditions, fracture morphologies were observed by field emission scanning electron microscope (FESEM), and the microstructure in the near-surface region was characterized by transmission electron microscopy (TEM), respectively. Experimental results showed that LSP can obviously improve the ultimate tensile stress and elongation of LY2 Al alloy, and the strain rate sensitivity of the treated sample appeared to be remarkable. The improvement of tensile properties may be explained by the fact that the grain in the LSP-shocked region was obviously refined. Dynamic strain aging was found in the treated sample at the strain rate ranging from 0.00001 s−1 to 0.0001 s−1, and the underlying formation mechanism was revealed.

Research highlights▶ Effect of LSP on tensile properties of Al alloy is evaluated. ▶ The engineering stress-strain curves are investigated in both conditions. ▶ Effect of LSP on UTS (flow stress) and strain rate sensitivity are also analyzed. ▶ The results can provide some insights on the application of Al alloy by LSP.