Abstract
Laser shot peening is increasingly used as one of the better alternative methods to improve the surface
properties of structural components and for the in-suit preventive maintenance of nuclear reactor
componets. This paper attempts to investigate the effect of laser peening with a low energy laser
(300 mJ, 1064 nm, 10 ns) on precipitation hardened aluminum alloy Al-6061-T6 with and without
sacrifi cial coating on the target surface. The laser peened and unpeened surfaces were characterized
using XRD based surface residual stress measurement, SEM, AFM based roughness analysis and micro
hardness measurements. The study concluded that low energy laser is enough to impart compressive
residual stress on the surface. Micro hardness study conformed the hardening of laser peened surfaces
and depth profi le study indicate the presence of strain hardened layer up to 0.7 mm from the top surface.
