Laser shock peening for LY2 alloy

In order to study the effects of laser shock peening on the fatigue life of LY2 aluminum alloy, water and aluminum foil were used for confining medium and ablation medium, respectively. LY2 specimens were processed with YAG laser. The laser peening parameters were: wavelength of 532 nm, pulse duration of 10 ns, and output energy of 5 J. The laser was focused on a spot of diameter 3 mm. The experimental results show that laser shock peening can increase aluminum fatigue life by 110%. Fracture analysis results show that laser shock peening strengthens the metal surface and suppresses the crack’s initiation and expansion, improving the aluminum fatigue performance．