基于激光表面微纳结构的胶接性能研究进展

胶接具有独特的性能而被广泛关注，但在实际应用中往往由于界面结合强度不足而导致接头在服役过程中过早失效。激光表面处理是一种能够有效提高胶接接头表面性能的方法，通过激光表面处理会使黏接材料表面形成不同的表面微纳结构，从而改善接头的性能。首先介绍了激光表面处理原理及激光器分类，对比了不同激光器的优缺点及加工质量特性，分析了激光加工参数对接头强度的影响。其次从激光加工不同表面微纳结构入手，阐述了不同表面微纳结构的加工方式，分析了不同表面微纳结构对不同材料接头强度的影响。此外，针对不同的表面微纳结构，其结构参数有所不同，导致接头表面化学成分和润湿性能也有所不同，使得接头强度有所差异，在此基础上分析了微纳结构参数对接头强度的影响及原因。同时，胶层间的作用机制与接头强度具有密不可分的联系，研究表明，不同的表面微纳结构对胶层的作用机制具有明显的不同，归纳总结发现，经激光表面处理形成表面微纳结构后接头表面粗糙度、化学性质、润湿性能及胶层间裂纹的扩展对接头强度的提升具有一定作用。最后，对激光表面处理微纳结构的研究进行了展望。

Research Progress of Adhesive Bonding Properties Based on Laser Surface Micro and Nano Structures

Adhesive bonding has been widely concerned with its unique properties, but in practical applications, it often leads to premature failure of the joint in service due to insufficient interfacial bonding strength. Laser surface treatment is a method to effectively improve the surface performance of the adhesive joint, which will make the surface of the bonding material form a different surface micro nano structure, thus improving the performance of the joint. Firstly, the principle of laser surface treatment and the classification of lasers are introduced, which are mainly divided into short-pulse lasers (nanosecond lasers) and ultrashort-pulse lasers (picosecond lasers and femtosecond lasers), and the advantages and disadvantages of different lasers and the processing quality characteristics are compared. The nanosecond laser is the most widely used in the field of adhesive bonding due to its low cost and excellent stability, the picosecond laser is suitable for the processing of surface micrometer structure due to its characteristics, and the femtosecond laser is suitable for the processing of surface delicate structure. Meanwhile, the effect of parameters such as the laser power, spot overlap rate, pulse energy and wavelength on the strength of the joint is analyzed. Secondly, starting from laser processing of different surface micro structures, a variety of micro and nano structures such as surface pits, grooves, grids, rings, and their processing methods are expounded. The effects of laser processing parameters on the morphology of micro and nano structures and the effects of different surface micro and nano structures on the joint strengths of different materials are analyzed and the enhancement effect and applicable scenarios in comparison with the characteristics of micro and nano structures are investigated. In addition, for different surface micro and nano structures, their structural parameters such as width, depth, diameter, density, etc. are different, resulting in different chemical composition and wettability properties of the joint surface, which makes the contact area between the adhesive and the joint surface different. It is found that these micro and nano structural parameters can effectively improve joint strength within a certain range, but beyond this range, they often lead to bubbles retained in the micro and nano structures, resulting in defects in the joints and thus reducing the strength of the joints. At the same time, the mechanism of action between the adhesive layers is inextricably linked to the strength of the joint. Different surface micro and nano structures have significantly different mechanisms of action on the adhesive layer. According to the research literature in recent years in China and abroad, it is summarized and found that after laser treatment can form surface micro and nano structures and change the surface roughness of the joint, thereby increasing the surface of the joint and the contact area of the adhesive, increasing the surface of the joint and the number of mechanical interlocking with the adhesive, promoting the joint surface and adhesive to form chemical bonding cooperation, enhancing the adhesive in the joint surface wettability and surface micro and nano structures, inhibiting crack emergence and expansion, and having a certain effect on the enhancement of joint strength. Finally, based on the current problems and technical applications of laser surface treatment of micro and nano structures, the development of adhesive bonding performance of laser surface treatment of micro and nano structures is prospected.