激光烧蚀坑阵列微结构对7075-T6粘接强度的影响

为了研究脉冲能量和烧蚀坑重叠率对7075-T6铝基板粘接强度影响, 采用纳秒光纤脉冲激光在粘接区域加工烧蚀坑阵列微结构, 通过表面形貌、剪切强度和断裂模式等实验参量对粘接效果进行了分析。结果表明, 脉冲能量对表面形貌、剪切强度及断裂模式几乎无影响; 随着烧蚀坑重叠率的增加, 表面粗糙度先增加后减小, 表面面积增加比一直增加; 与原始材料相比, 激光处理后剪切强度至少提升150%;当烧蚀坑重叠率为30%时, 粘接区域发生内聚断裂的面积最大, 剪切强度提升最明显; 脉冲能量为880μJ、烧蚀坑重叠率为30%时, 剪切强度为27.76MPa, 提升最大。该研究对激光烧蚀提高7075-T6粘接强度是有帮助的。

Effect of laser ablation crater array microstructure on bonding strength of 7075-T6

In order to study the effect of pulse energy and ablation crater overlap rate on the bonding strength of 7075-T6 aluminum substrate,a nanosecond fiber pulse laser was used to process the ablation crater array microstructure in the bonding area,and the bonding effect was analyzed based on the surface morphology,shear strength and fracture mode.The results show that the pulse energy has almost no effect on the surface morphology,shear strength,and fracture mode.As the overlap rate of ablation crater increases,the surface roughness first increases and then decreases,while the developed interfacial area ratio keeps increasing.Compared with the original material,the shear strength after laser treatment is increased by at least 150%.When the ablation crater overlap rate is 30%,the largest cohesive fracture area of the bonding area is obtained,and the most significant increasement of the shear strength is observed.When the pulse energy is 880μJ and the ablation crater overlap rate is 30%,the shear strength is 27.76MPa,which is the largest increasement.This study is helpful for improving the bonding strength of 7075-T6 by laser ablation.