微尺度下激光冲击对纯铜表面形貌的影响

为了研究微尺度下激光冲击过程中冲击波对强化表面塑性变形的影响,进行不同能量和冲击次数下激光微冲击纯铜试样处理,并对冲击试样进行表面形貌测量。结果表明,微尺度下,激光诱导的等离子体冲击波引起的轴向和径向压力同时对冲击表面作用。轴向压力在光斑中心区域附近起主导作用,冲击区域深度方向上塑性变形量随着激光能量和冲击次数的增加而增大;光斑边缘附近,主要受径向压力作用,随着激光能量的增加,径向塑性变形影响区域增大。当激光能量超过70 mJ 时,单点塑性变形边缘区域明显凸起;径向塑性变形随着冲击次数的增加先增大后减小,冲击次数高于3次时,光斑边缘附近明显凸起。

Surface response of copper treated by laser shock processing with microscale

To investigate the influence of shock wave in laser shock processing with microscale on shocked surface, experimental research of copper with different energy and shock number was carried out in the paper, and surface topography was measured. The results show that plastic deformation induced by shock wave with microscale is the interactive effect of pressure in both axial and radial direction. Pressure in axial direction plays a dominant role nearby the centre of laser beam, the amount of the plasticity deformation increases with increament of laser energy and shock number; Pressure in radial direction plays a leading role nearby the periphery, region of plastic deformation in radial direction increases with increament of laser energy, and spot edge is significantly salient when laser energy is over 70 mJ; Plastic deformation in radial direction increases first and then decreases with increasement of shock number, bulging deformation at spot edge is serious when shock number is over 3 times.