Analysis of microstructural evolution properties based on laser shock peening

Laser shock peening changes the microstructure of a metal surface and causes the severe plastic deformation. This paper studied the changes in the crystal dislocation density and grain size of the microstructure after laser shock peening. The finite element method was used to calculate the deformation of the LY2 aluminum after the laser shock peening under the different number of impact times. Through a subroutine programming, the microstructure prediction programming was embedded into the finite element model to analyze the dislocation density and grain size of the metal. Based on the simulation of the metal microstructure deformation under different laser impact times, it was found that with the increase of the impact times, the growth rate of the plastic deformation layer and the severe plastic deformation layer decreased. At the same time, the grain size refinement rate gradually declined. When the impact times exceeds four, the depth of the severe plastic deformation layer and the grain size have almost no change.