激光表面处理提高铝合金胶接接头强度的研究

Research on Laser Surface Treatment to Improve the Strength of Aluminum Alloy Adhesive Joint

粘接作为重要的汽车轻量化连接技术之一,胶接接头的强度和性能是我们关注的重点,胶接接头的强度和性能完全取决于胶粘剂接触的表面类型,因此在粘接之前对基材表面进行一定处理是粘接工艺中最重要的环节之一。金属的表面处理包括溶剂擦拭、机械打磨、化学清洗和酸蚀。激光表面处理是一种新型绿色环保的表面处理工艺,它可以高速有效的清洁材料表面附着物,并且改变材料表面微观结构及材料表面自由能及浸润性。从而提高粘接接头十字拉伸强度、单搭接拉伸剪切强度和接头耐水性能。通过激光处理,所有接头的破坏形式由界面破坏转为内聚破坏。对铝合金环氧结构胶2098G胶接接头而言,十字拉伸强度、剪切强度和水浴剪切强度,激光处理后比溶剂擦拭分别提高了17.8%,133.8%,88.1%。对铝合金聚氨酯结构胶TS6015胶接接头而言,十字拉伸强度、剪切强度和水浴剪切强度,激光处理后比溶剂擦拭分别提高了698%,225%,223%。激光表面处理有效的使铝合金胶接接头的强度达到胶的本体强度的94%~100%,是铝合金粘接的有效表面处理方法。

Bonding as one of the important automotive lightweight joining technologies, the strength and performance of the bonded joint is a key concern. The strength and performance of the bonded joint depends entirely on the type of surface the adhesive contacts, so certain treatment of the substrate surface prior to bonding is one of the most important aspects of the bonding process. Surface treatment of metals includes solvent wiping, mechanical polishing, chemical cleaning and acid etching. Laser surface treatment is a new green surface treatment process which can clean the material surface adhesion at high speed and effectively, and change the material surface microstructure and the material surface free energy and wettability. This improves the cross tensile strength of bonded joints, the tensile shear strength of single lap joints and the water resistance of joints. By laser treatment, the damage of all joints is changed from interfacial damage to cohesive damage. For aluminium alloy epoxy structural adhesive 2098 G bonded joints, the cross tensile strength, shear strength and water bath shear strength were increased by 17.8%, 133.8% and 88.1% respectively after laser treatment compared to solvent wiping. For the aluminium alloy polyurethane structural adhesive TS6015 adhesive joint, the cross tensile strength, shear strength and water bath shear strength were increased by 698%, 225% and 223% respectively after laser treatment compared to solvent wiping.The laser surface treatment is an effective surface treatment for bonding aluminium alloys by achieving 94% to 100% of the strength of the bonding body. It is an effective surface treatment method for aluminum alloy bonding.