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探讨了单脉冲同点间隔多次(SPI)工艺对激光微织构加工效果的影响。采用纳秒倍频Nd3+∶YAG激光器在45钢表面进行激光微织构实验,研究激光能量密度、脉冲个数对微凹腔几何形貌参数的影响规律;分析烧蚀所致表面等离子体对激光吸收率的影响;并从实验和温度场模拟角度,对比分析了SPI工艺相比同点连续多次工艺的特点及技术优势。结果表明:随激光能量密度增加,微凹腔直径呈对数函数关系增加,而凹腔深度则随之先增大后趋于平稳,最后略微下降。作用脉冲个数对凹腔直径影响不明显,但凹腔深度随之呈线性增加。较之同点连续多次工艺,SPI工艺能最大限度降低激光加工产生的负面热效应,且多脉冲作用对微织构内部形貌具有“平滑”作用;同时,在保证单个脉冲材料去除率的条件下,提高了激光加工高质量微织构的总效率。
The effect of single-pulse SPI process on laser micro-texture processing was discussed. The effects of laser energy density and number of pulses on the geometrical parameters of the micro-cavity were investigated by laser micro-texture testing on the surface of 45 steel with the nanosecond-doubling Nd3 +: YAG laser. The effects of laser ablation Absorption rate; and from the experimental and temperature field simulation point of view, comparative analysis of SPI process compared to the same point a number of consecutive characteristics and technical advantages. The results show that with the increase of laser energy density, the diameter of the microcavity increases logarithmically, while the depth of the cavity increases first and then becomes stable, and finally decreases slightly. The effect of pulse number on the cavity diameter is not obvious, but the cavity depth increases linearly. Compared with the same process, the SPI process can minimize the negative thermal effect caused by laser processing, and the multi-pulse effect has a “smooth” effect on the internal morphology of the micro-texture. At the same time, Under the conditions of the laser processing to improve the overall quality of high-quality micro-texture.