This study investigates the frictional influence of different rivet coatings on the joint quality and strength of self-piercing riveted aluminum alloys. A mechanically plated Zn-Sn-Al (Almac®) and an electroplated Zn–Ni coating were applied to the steel rivets to examine the frictional effect of rivet coatings. The friction properties of the rivet coatings were evaluated using a micro-mechanical surface tester. The results demonstrated that the friction properties of the rivet coatings remarkably influenced both the joint quality after riveting and the mechanical behavior of the joints. Under a similar riveting condition, owing to the lower friction coefficient, the Zn-Ni-coated rivets experienced deeper rivet head penetration and larger interlocking in terms of joint quality compared to those of Almac®-coated rivets with a higher friction coefficient. However, under a similar joint quality with respect to the appropriate riveting parameters, the joints with Almac®-coated rivets exhibited higher lap-shear and cross-tensile loads owing to the higher frictional force at the rivet/sheet interface compared to the joints with Zn-Ni-coated rivets. The surface profiles of the coatings after applying an external load using a micro-mechanical surface tester revealed a larger plastic deformation and subsequently higher delamination of the Almac® coating during the riveting process, which altered the friction properties at the rivet/sheet interface and thereby contributed to the higher lap-shear and cross-tensile loads. A numerical analysis also elucidated a significant effect of the friction coefficient at the rivet/sheet interface on the joint quality and lap-shear behavior, which is consistent with the experimental results.

本研究研究了不同铆钉涂层对自冲铆接铝合金的接头质量和强度的摩擦影响。将机械镀锌锌锡铝（Almac®）和电镀锌镍涂层应用于钢铆钉，以检查铆钉涂层的摩擦效果。使用微机械表面测试仪评估铆钉涂层的摩擦性能。结果表明，铆钉涂层的摩擦性能显着影响铆接后的接头质量和接头的机械性能。在类似的铆接条件下，由于较低的摩擦系数，与具有较高摩擦系数的Almac®涂层铆钉相比，Zn-Ni涂层铆钉在铆接质量方面具有更深的铆钉头穿透力和更大的互锁性。但是，在适当的铆接参数下，在类似接头质量的情况下，与采用Almac®涂层铆钉的接头相比，在铆钉/薄板界面处的摩擦力更高，因此具有较高的搭接剪切和横向拉伸载荷。镀锌镍的铆钉。使用微机械表面测试仪施加外部载​​荷后，涂层的表面轮廓显示出在铆接过程中Almac®涂层具有较大的塑性变形和较高的分层，从而改变了铆钉/薄板界面的摩擦性能，从而增加了搭接剪切和横向拉伸载荷。数值分析还阐明了铆钉/片材界面处的摩擦系数对接头质量和搭接剪切行为的显着影响，这与实验结果一致。