Abstract
In the automobile industry, multi-material structure of car body is progressing with the aim of reducing CO2 emission and reducing fuel consumption. As a joining technique, adhesive bonding joint is possible to bond dissimilar materials, and since it is surface joining, it is considered to be useful. However, adhesive bonding is a complementary technique for other joining approaches due to its instability of reliability and durability, and improvement of strength of the joint itself. Thus, it is expected that the interfacial strength will be improved by removing the weak boundary layer on the surface of the adherend and using the anchor effect and the increasing in surface area produced due to the uneven shape. Therefore, in this study, in order to improve the interface strength between the adherend and the adhesive, the laser patterning treatment was applied as the surface treatment, fatigue properties of the adhesive bonding joint were evaluated and were compared to the untreated specimens. As a result, the static and fatigue strength of the joint were improved by the surface treatment. In particular, the joint strength was further improved by removing the weak boundary layer on the entire surface as the laser irradiation. Therefore, processing conditions have been established based on usefulness of surface treatment in fatigue strength of joint with high strength and high reliability.
