Influence of Multiple Laser Shock Peening without Coating on Ti-6Al-4V Alloy for Aircraft Applications

International audienceThe current research proposes multiple laser shock peening without coating (LSPwC) process for aircraft titanium Ti-6Al-4V alloy using low energy Nd: YAG laser. The low energy of 350 mJ in at the fundamental wavelength 1064 nm is utilized for the laser surface modification process. The compressive residual stress measurements are accomplished according to X-ray diffraction sin 2 Ψ method. The surface morphology and surface roughness profiles were characterized using atomic force microscope and roughness profilometer respectively. The surface microstructure is examined by scanning electron and optical microscopes. Further, the mechanical properties of laser shock depth hardened layers were systematically analyzed through Vickers microhardness tester. Introduction. Laser shock peening is a nonconventional surface modification technique. Laser peening uses impulsive pulse of high energy density that laser ablation induces shock waves which triggers compressive residual stress due to plastic deformation of material than conventional shot peening thus enhances the properties such as increase in hardness, roughness, prevent crack growth, increase in fatigue life, increase in corrosion resistance. Laser shock peening can be done by two ways low energy or high energy. This paper is completely followed low energy with focused beam by using a converging lens. Material was confined with aqueous (water) medium. Plasma pressure generation takes place as the beam strikes the surface hence, plasma has the tendency to not escape the water. Water acts as confinement layer [1-4]