Laser irradiation effects on the hardness of Al 5086 alloy have been investigated by using
KrF Excimer laser of 248 nm wavelength, 23 mJ pulse energy, 20 ns pulse duration, and 100
Hz repetition rate. The square-shape samples were irradiated in air as well as in vacuum (∼
10− 3 mbar) with a defocused beam of spot size 3.14 mm2 at the target surface, where the
laser fluence was 0.73 J/cm2 and laser intensity≈ 3.7× 107 W/cm2. The number of shots
were varied from 100 to 500, and its influence on the hardness profile and on the …