In the fabrication of joined materials between anodized aluminum alloy and polymer, the performance of the metalpolymer joining is greatly influenced by the chemical properties of the oxide film. In a previous study, the dependence of physical joining strength on the thickness, structure, pore formation, and surface roughness of films formed on aluminum alloys is investigated. In this study, we investigated the effect of silane coupling treatment on the joining strength and sealing performance between aluminum alloy and polymer. After a two-step anodization process with additional treatment by silane, the oxide film with chemically modified nanostructure is strongly bonded to the polymer through physical and chemical reactions. More specifically, after the two-step anodization with silane treatment, the oxide film has a three-dimensional (3D) nanostructure and the silane components are present in combination with hydroxyl groups up to a depth of 150 nm. Accordingly, the joining strength between the polymer and aluminum alloy increases from 29 to 35 MPa, and the helium leak performance increases from 10−2-10−4 to 10−8-10−9 Pa m3 s−1.

Abstract
1. Introduction
2. Experimental Methods
3. Results and Discussion
4. Conclusions
References

• Sung-Hyung Lee(Gakkō hōjin Kitahara gakuen/Department of Chemistry and Biological Science, Iwate University/Shakai fukushi hojin wayo-kai) Corresponding author
• Hitoshi Yashiro(Department of Chemistry and Biological Science, Iwate University)
• Song-Zhu Kure-Chu(Materials Function and Design, Nagoya Institute of Technology)