ABSTRACT

Laser processing has been used as a surface preparation before adhesive bonding, which significantly improves the adhesion between the adhesive and the substrates. In this work, a pulsed fiber laser was used to process different microgrooves in the bonding region of a Ti6Al4V substrate. First, the pulse energy was optimized, and then the effects of the microgroove parameters (groove pattern, depth, and distance) on the surface roughness of the substrate and on the shear strength and failure mode of the adhesive joints were studied using a single factor experimental design. The results show that when the pulse energy is greater than 63 μJ, a significant amount of molten residue is generated around the groove. The parallel groove is the most beneficial to improve the shear strength when the groove direction is 90° (when the groove is perpendicular to the loading direction). In contrast, cross grooves easily form pores that are not filled with adhesive, which weakens the shear strength. The shear strength was observed to decrease for greater groove distances and increase with the groove depth. The maximum shear strength of the adhesively bonded joint after laser processing is about 29.71 MPa, which is an increase of 140% compared with that by surface grinder polishing.

摘要

激光加工已被用作粘合剂粘合前的表面处理，可显着提高粘合剂与基材之间的粘合力。在这项工作中，使用脉冲光纤激光器在 Ti6Al4V 基板的结合区域加工不同的微槽。首先对脉冲能量进行优化，然后单因素研究微槽参数（槽纹、深度和距离）对基体表面粗糙度和粘接接头剪切强度和失效模式的影响。实验设计。结果表明，当脉冲能量大于 63 μJ 时，凹槽周围会产生大量的熔渣。平行槽在槽方向为90°时（当槽与加载方向垂直时）最有利于提高抗剪强度。相比之下，交叉槽容易形成未填充粘合剂的孔隙，从而削弱剪切强度。观察到剪切强度随着凹槽距离的增加而降低，并随着凹槽深度的增加而增加。激光加工后粘接接头的最大剪切强度约为29.71 MPa，与平面磨床抛光相比提高了140%。