飞秒激光烧蚀0Cr18Ni9不锈钢精度的影响因素  

Influence factors of precision of femtosecond laser ablating 0Cr18Ni9 stainless steel

作　　者：彭丽勇 唐鹏[1] 林家新 郭亮[1,2] 张庆茂[1] 

机构地区：[1]华南师范大学广东省微纳光子功能材料与器件重点实验室,广州510006 [2]华南理工大学机械与汽车工程学院,广州510641

出　　处：《强激光与粒子束》2014年第8期81-86,共6页High Power Laser and Particle Beams

基　　金：国家高技术发展计划项目;中央财政支持地方高校专项资金项目(510-C10293);广东省教育厅学科建设专项项目(CXZD1139);华南理工大学国家金属材料近净成形工程技术研究中心开放基金项目(2011006)

摘　　要：为了研究影响飞秒激光烧蚀0Cr18Ni9不锈钢精度的因素,采用飞秒激光对0Cr18Ni9不锈钢进行了切割和打孔实验。利用光学显微镜、光学金相显微镜等设备,对不锈钢烧蚀区形貌和切缝显微组织进行检测,基于烧蚀过程中CCD实时采集到的不锈钢表面的激光光斑图样,采用COMSOL Multiphysic数值模拟软件,模拟了烧蚀过程中激光束的发散传播行为,并计算了光束发散角。结果表明:当激光重复频率为5kHz时,厚度为160μm的0Cr18Ni9不锈钢切缝和孔边缘被明显烧黑,切缝处晶粒明显长大,存在热影响区;烧蚀过程中,由飞秒激光超高功率密度所致的金属-空气混合等离子体使光束沿传播方向上发生散射,发散角在6°～10°之间。热影响区的存在和混合等离子体的行为是影响飞秒激光烧蚀0Cr18Ni9不锈钢精度的主要因素。The 0Crl8Ni9 stainless steel sheet was cut and drilled by a femtosecond laser, and the influence factors of machi- ning accuracy of femtosecond laser ablation were studied. The morphology of stainless steel ablation zone and metallographie struc- ture of cutting seam were examined by means of Nikon SMZ800 optical microscope and 4XC optical metallographic microscope. Based on the laser speckle on the surface of stainless steel observed by a coaxial CCD in the process of stainless steel ablation, the laser beam divergent propagation behavior was simulated using COMSOL Multiphysic numerical simulation software, and the beam divergence angle was calculated. Experimental and simulation results demonstrate that when the laser repetition rate is 5 kHz, the edge of cutting seam and hole are obviously blackened; metallographic phase shows that grain size significantly gets lar- ger at cutting seam and heat affected zone can＇t be avoided in the femtosecond laser ablation process; metal-air hybrid plasma in- duced by ultra-high power density femtoseeond laser makes the laser beam scatter along the direction of propagation in the process of machining, the divergence angle is between 6° to 10°. The existence of heat affected zone and the behavior of the metal-air hy- brid plasma are the main factors influencing the precision of femtosecond laser ablation.

关 键 词：飞秒激光 激光烧蚀 不锈钢薄片 热影响区 金属-空气混合等离子体 

分 类 号：O436[机械工程—光学工程]