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采用高温无氧铜材料,实验研究激光冲击压力作用下铜材料表面微坑的几何特征以及尺寸效应作用规律。通过控制热处理温度与保温时间,在厚度截面方向获得多种不同晶粒粒径的试样,结合2种不同光斑大小的实验,研究激光冲击表面高应变率塑性变形的大小效应作用特征。实验结果表明:在相同激光能量条件下,大光斑冲击产生的微坑深度较大。晶粒粒径对微坑深度有较大的影响,小晶粒条件下,产生的坑深较小;大晶粒条件下,光斑大小与晶粒粒径对于坑深的影响较为显著。
The high temperature oxygen-free copper material was used to experimentally study the geometric characteristics of the micro-pits on the surface of copper material and the rule of the size effect under laser shock pressure. By controlling the heat treatment temperature and holding time, a variety of samples with different grain sizes were obtained in the direction of the thickness cross section. Combined with the experiment of two different spot sizes, the effect of the size effect on the high strain rate plastic deformation of the laser striking surface was studied. The experimental results show that under the same laser energy, the depth of micro-pits generated by large spot impact is larger. The grain size has a great influence on the depth of dimples, and the crater depth is small under the conditions of small grains. The effect of spot size and grain size on pit depth is significant under the conditions of large grains.