面向碳纤维增强树脂基复合材料/钢异质结构连接的汽车钢板高速激光毛化工艺研究  

Study on Laser Surfi-Sculpt of GMW2 Autobody Sheet Steel for Carbon Fiber Reinforced Polymer/Steel Dissimilar Joint

作　　者：谭向虎[1] 单际国[1,2] 唐磊[1] 陈武柱[1] 

机构地区：[1]清华大学机械工程系激光加工研究中心,北京100084 [2]清华大学先进成形制造教育部重点实验室,北京100084

出　　处：《中国激光》2015年第3期46-52,共7页Chinese Journal of Lasers

基　　金：国家自然科学基金(51275271)

摘　　要：为了解决激光连接碳纤维增强树脂基复合材料(CFRP)/钢异质接头中的缩孔问题,采用光纤激光对GMW2钢板进行高速毛化试验,系统研究了激光功率、扫描速度、扫描长度和扫描次数对微凸起宽度和高度的影响,并利用高速摄像实时观察了毛化过程。结果表明,微凸起宽度与熔池宽度相当,增加激光功率或减小扫描速度将导致熔池宽度增加,微凸起宽度也将增加;而扫描长度和扫描次数不影响熔池的宽度,因此微凸起宽度也不发生变化。微凸起高度由蒸气压力、表面张力和液体动压力决定,激光功率增加将导致蒸气压力的增加和表面张力的减小,液态金属向熔池尾部流动的驱动力增大,适当地增加激光功率有利于微凸起的长高,但激光功率过高将产生大量飞溅,导致微凸起高度不稳定;随着扫描速度的增加,蒸气压力、表面张力和液体动压力都将发生变化,熔池液体流动的驱动力和阻力存在竞争关系,导致微凸起高度呈先增加后减小的趋势;扫描长度增加,蒸气压力水平分量增大,驱动力增加,微凸起高度逐渐增大。To solve the problem of shrinkage voids in carbon fiber reinforced polymer（CFRP）/steel dissimilar joint,the fiber laser surfi- sculpt on the GMW2 autobody sheet steel is adopted. The effects of laser power,scanning speed, scanning length and scanning repeats on the width and height of protrusion are systematically investigated. The laser surfi-sculpt process is studied by high speed visual detection system. The results show that the protrusion width is the same as the molten pool width. Increasing the laser power or decreasing the scanning speed will cause the increase of molten pool width, leading the protrusion width to increase. While scanning length and scanning repeats do not affect the molten pool width, so they have no effect on protrusion width. The protrusion height is determined by vaporization pressure, surface tension and hydrodynamic pressure. With the laser power increasing, the vaporization pressure increases and the surface tension decreases. Namely the driving force for the liquid metal flow to the behind of molten pool increases. So the appropriate increase of laser power is beneficial for protrusion to grow taller. When the laser power is too high, a large number of spatters will be produced, leading to the protrusion height instable. With the increase of scanning speed, vaporization pressure, surface tension and hydrodynamic pressure will change. There is a competition between driving force and resistance, which leads the protrusion height first to increase and then decrease. With the increase of scanning length, the horizontal component of vaporization pressure and the driving force increase, leading to the increase of protrusion height.

关 键 词：激光技术 高速激光毛化 微凸起几何形貌特征 毛化工艺控制 汽车钢板 

分 类 号：TG456.7[金属学及工艺—焊接]