Effect Analysis of Laser Shock Peening on Nickel-based Alloys by Laser Solid Forming

Laser solid forming has the advantages of rapid and complex shapes, but the stress caused by high temperature gradient changes during the forming process can easily lead to the deformation of parts and insufficient mechanical properties. This article focuses on laser solid forming GH4169 superalloy for laser shock peening. The influence of process parameters on surface morphology and toughness were analyzed. The mechanism of laser shock peening was analyzed. The results show: As the number of impacts increases, the depth gradually increases, and the increasing trend slows down. When the energy is small, the surface change cannot be observed. After 5J, as the energy increases, the depth of the pit increases. As the impact energy increases, the toughness of the material first increases and then decreases. The toughness of the material is the highest at 6J, reaching 65J/cm². The action mechanism of laser shock peening has three main methods, one is fine-grain strengthening, the other is twinning and work hardening, and the third is stress strengthening. (paper)