Abstract
In order to improve the fuel economy of automobiles, the need for reducing the weight of vehicles has been drastically increased. By joining Al alloys which are light weight, high strength and excellent in productivity has attracted attention. In the previous research, we obtained a high strength joint which bonded in the N2 atmosphere because the oxide film on the surface of the Zn insert material was replaced and removed by using the Zn sheet subjected to the formate coating treatment. In this study, focusing on the mechanical destruction behavior of the superficial oxide film on the Al alloy side, the influence of the bonding surface roughness on the Al alloy side in the bonding in air was investigated. As a result, when the Al bonding surface was polished by SiC paper # 500, the bonding strength was the highest. This is considered to be suitable for mechanical destruction of the oxide film of Al and discharge of the liquid phase consisting of Zn and Al.
