铝合金与CF/PA66激光直接连接工艺及化学成键研究  

Investigation on Laser Direct Joining of Aluminum Alloy-CF/PA66 and Chemical Bonding Mechanism

作　　者：冯紫微 周宝升 张涛 牛得田 张雪妍 梁圣明 宋晓国 檀财旺[1,2] Feng Ziwei;Zhou Baosheng;Zhang Tao;Niu Detian;Zhang Xueyan;Liang Shengming;Song Xiaoguo;Tan Caiwang(Shandong Provincial Key Laboratory of Special Welding Technology,Harbin Institute of Technology at Weihai,Weihai 264209,Shandong,China;State Key Laboratory of Advanced Welding and Joining,Harbin Institute of Technology,Harbin 150001,Heilongjiang,China;National Invitation Center of High Speed Train at Qingdao,Qingdao 266108,Shandong,China)

机构地区：[1]哈尔滨工业大学(威海)山东特种焊接技术重点实验室,山东威海264209 [2]哈尔滨工业大学先进焊接与连接国家重点实验室,黑龙江哈尔滨150001 [3]国家高速列车青岛技术创新中心,山东青岛266108

出　　处：《中国激光》2022年第13期42-50,共9页Chinese Journal of Lasers

基　　金：国家自然科学基金(52074097);国家高速列车技术创新中心研发计划[CXKY-02-02(2020)]。

摘　　要：铝合金与轻质高强的碳纤增强尼龙66复合材料(CF/PA66)的高质量连接是实现轨道交通等领域结构轻量化的重要手段之一。然而,由于二者物化差异大,二者难以实现激光直接连接。为探究铝合金与CF/PA66激光直连工艺及其连接机理,以激光功率为变量,揭示了不同热输入下接头宏观形貌、CF/PA66熔化宽度及界面结合的变化规律,建立了激光功率与接头拉剪性能的联系。结果表明,随着激光功率的增加,CF/PA66熔宽增加,铝合金与CF/PA66的实际接触面积扩大,从而接头承载力提高。然而,热输入过高将会导致树脂分解,界面产生气孔,接头性能降低。接头拉剪力在激光功率为1100 W时达到最大值2571.6 N(拉剪强度为10.2 MPa)。能谱与X射线光电子衍射仪(XPS)的分析结果表明,铝合金与CF/PA66激光直连过程中界面产生了新的化学键“Al—O—C”及“Al—C”,二者因此形成了紧密的界面冶金结合,进而获得了高质量接头。Objective Joining light materials have become an important way to achieve the lightweight of automotive,rail transportation,and other fields.Carbon fiber reinforced nylon composites(CF/PA)are thought to a promising application due to high specific strength and modulus.However,a hybrid joint of lightweight metals and CF/PA is necessary when considering the cost of CF/PA.Moreover,joining aluminum alloys with high thermal conductivity and low price to CF/PA plays a significant role in saving energy and reducing emission.To overcome the shortcomings of traditional mechanical connection and adhesive bonding,various welding methods have been investigated for joining aluminum alloys to CF/PA such as laser welding,friction stir welding,and induction welding.Thereinto,the laser as a heat source possesses a flexible controllability and a less heat affected area to base materials.A high-quality joint can be obtained via optimizing the process parameters and strengthening the interface bonding though some differences in physical and chemical properties exist between two materials.The melting point of CF/PA66is higher than those of the other PA composites,which causes a narrow process window.So far,few researches are performed to investigate the laser joining of aluminum alloys to CF/PA66.Therefore,in the current study,laser power is chosen as a variable to confirm the possibility of direct joining aluminum alloys to CF/PA66,and the bonding mechanism is finally revealed.Methods The 1.5 mm-thick 6061aluminum alloy and a 3 mm-thick carbon fiber reinforced composite(CFRTP)are selected to perform the laser direct joining.The resin substrate of CFRTP is polyhexamethylene adipamide(PA66).The traveling speed and defocus distance are kept constant,and the laser power is changed from 900 Wto 1300 W with an interval of 100 W to investigate the effect of heat input on the interface bonding and the corresponding joint characteristics.Tensile shear tests with a stretch speed of 2mm/s are adopted to evaluate the mechanical properties.The m

关 键 词：材料 激光连接 碳纤增强尼龙66复合材料 铝合金 结合机理 化学键 

分 类 号：TG456.7[金属学及工艺—焊接]