Pulsed Nd:YAG laser shock processing effects on mechanical properties of 6061-T6 alloy

• Effect of LSP on mechanical properties of 6061-T6 alloy is evaluated.
• Single shot LSP and double shot LSP are applied on material surface.
• The residual stresses changed depending on the number of shots.
• The tensile properties of 6061-T6 alloy are greatly improved by LSP.

The aim of this paper is to investigate effects of single and double shot Nd:YAG laser shock processing (LSP) on residual stress, micro-hardness and tensile properties of 6061-T6 aluminum alloy. The X-ray diffraction technique was used to measure surface residual stress in LSP-treated 6061-T6 samples. The magnitude and directional dependence of the surface residual stress after single shot and double shot LSP were investigated with the sin2 Ψ method. The results show that laser shock processing can significantly increase surface compressive residual stress. In addition, micro-hardness of the LSP-treated sample was measured using a Vickers diamond indenter depending on the depth. The tensile tests of the single shot and double shot LSP-treated and untreated samples were carried out by the Schimadzu tensile testing machine having a video extensometer. Experimental results show that the values of micro-hardness, tensile strength and uniform elongation increase by LSP.