界面微结构对PA6/铝合金连接性能的影响

Effects of the Surface Microstructure on the Joint Mechanical Properties of PA6/Aluminum Alloy Pressing Molded Specimen

采用抛光或抛光-化学刻蚀对铝合金表面进行预处理,获得微纳米结构表面,再利用自制模具对铝合金与尼龙6(PA6)进行热压成型。用扫描电镜、激光共聚焦显微镜观察发现,硫酸刻蚀形成的微纳米结构表面有利于树脂在铝合金表面形成良好的机械互锁结构,实现PA6/铝合金优良的连接性能。力学性能测试显示,硫酸刻蚀后的PA6/铝合金连接试样拉伸剪切强度达到了19. 1 MPa,界面粘结性能最优,比抛光后的连接试样提高了870%,其失效模式由界面失效变为内聚失效。

Micro-nano structures on aluminum alloys surface were pretreated through polishing, and/or chemical etching. The PA6/ aluminum alloy specimens were fabricated by hot pressing in the self-made mold. The surface morphologies of the samples were examined by the field emission scanning electron microscopy and the laser scanning confocal microscope. Results show that the micro-nano sized rougher surface of alloy after sulphuric acid corrosion leads to a stronger mechanical interlock structure between aluminum alloy and PA6, resulting in highly improved joint strength. The mechanical properties show that the tensile shear strength of sample after sulphuric acid etching reaches 19.1 MPa, and the maximum interfacial joint strength of the studied sample is obtained. Compared with sample without chemical etching,the shear strength of the etched sample increases about 870%. At the same time, the failure mode is changed from adhesive type to cohesive type.