激光冲击强化利用离子体力学效应在金属表面形成较深的残余压应力层,细化表层晶粒,大幅度提高金属抗疲劳、抗磨损和抗腐蚀等机械性能。目前现有实验手段很难获取超高应变速率下塑性变形过程中微观结构演变的动态过程。本文采用LAMMPS软件对在2×107s-1应变率,15 ns的加载时间,300 K温度下的多晶铜塑性变形行为进行分子动力学模拟,获得超高应变速率力学效应下多晶铜塑性变形微观结构的演变过程。超高应变率下力学效应作用下,形变孪晶是中层错能金属亚微米晶粒细化的主要变形方式。 Laser shock strengthening uses the ionic mechanical effect to form a deep residual compressive stress layer on the metal surface and refine the surface crystal grains, which greatly improves the mechanical properties of the metal against fatigue, abrasion and corrosion. At present, it is difficult to obtain the dynamic process of the microstructure evolution during the plastic deformation under the ultra-high strain rate by current experimental methods. In this paper, LAMMPS software was used to simulate the plastic deformation behavior of polycrystalline copper under the strain rate of 2 × 107s-1, loading time of 15 ns and temperature of 300 K to obtain the plastic deformation of polycrystalline copper under the effect of super-high strain rate The evolution of microstructure. Under the effect of mechanical strain at high strain rate, the deformation twin is the main deformation mode of the grain refinement of the intermediate-layer miscibility metal submicron.