复合硅烷化预处理对铝合金/环氧胶粘剂粘接强度的影响

研究了铝合金表面复合硅烷化预处理对铝合金与环氧胶粘剂粘接强度和粘接耐久性的影响,并与铬酸盐预处理进行了比较。用反射吸收红外光谱和透射电镜分析观察铝合金表面复合硅烷化膜层的结构,分别用扫描电镜、X-射线光电子能谱和俄歇能谱分析了不同粘接件断裂表面。结果表明,铝合金经复合硅烷化预处理能明显提高铝合金基体与环氧胶粘剂的粘接强度和粘接耐久性。搭接件断面呈现一层层撕开的破坏现象,而铬酸盐处理的搭接断裂件的断面较平齐。硅烷化处理的楔子试样断裂件的断裂面也呈现明显的韧性断裂,表明在铝合金与胶粘剂界面区域形成的Al-O-Si和硅氧烷共价键网络和复合硅烷化膜层表面的环氧基团起着明显的界面和表面改性作用。

Effect of composite silylanization pretreatment on bond strength of Al-alloy/epoxy adhesive

The effect of the composite silanization pretreatment of Al-alloy on bond strength and bond durability between Al-alloy and epoxy adhesive were studied,and were compared with the chromate pretreatment in this paper.The structure of the composite silanization film layer on Al-alloy surface was analyzed.The fracture surfaces of different bonding samples were analyzed by scanning electronic microscope,X-ray photoelectron spectroscopy and Auger spectrometer.The results showed that bond strength and bond durability between Al-alloy substrate and epoxy adhesive were improved obviously.The facture surface of lapping sample exhibited a layered teared behavior,yet the facture surface of lapping sample of the chromate pretreatment was flat.The facture surface of wedge test sample also exhibited markedly ductile rupture.All the results show that the Al-O-Si and siloxane networks formed in interface area between Al-alloy and adhesive as well as epoxy group on the composite silanization film layer surface play an evident role in interface and surface modification.