Effects of laser shock processing on mechanical properties of Fe–Ni alloy

The effects of laser shock processing (LSP) on nano-hardness, elastic modulus and surface residual stress of Fe–Ni alloy were investigated. The values of nano-hardness, elastic modulus of the Fe–Ni alloy after LSP were measured by the nano-indentation technology, and the surface residual stress was determined by XRD with sin2ψ method, and scanning electron microscopy (SEM) observations of the microstructure before and after LSP were carried out. Experimental results showed that the values of the nano-hardness, elastic modulus and surface residual stress in the laser-shocked region and the laser-affected region were obviously improved compared to those in the non-shocked region. The mechanisms underlying the improved nano-hardness, elastic modulus and surface residual stress were also addressed.