Author(s)

K. Tanaka, T. Teramura, T. Katayama, K. Nishiguchi

Abstract

In recent years, due to serious environmental issues, the development of the gasoline mileage improvement technology has been essential in the automotive industry which occupies most of the transportation section, which accounts for 18% of domestic carbon dioxide emissions. Weight-saving of the car body can contribute to improving the gasoline mileage. Carbon fiber reinforced plastics (CFRP) are expected to be used as materials for structural parts. Because of their expensive cost, however, CFRP monocoque body is only applied to luxury sports cars. To meet the demand of the reduction of the weight and affordable cost, a multi-materials body, a complex with CFRP and conventional materials such as aluminium and steel, has been proposed. For the adoption of a multi-material body, joining technologies for two different materials are necessary to be developed, and reasonable and practical high performance joining process has to be developed. Aluminum alloy has the properties such as weight-saving, high specific strength, formability, recyclability, and high designability. The conventional joining methods between CFRP and aluminium alloy are mechanical joining such as bolts, self-piercing rivets and adhesive joining. However, mechanical joining has the disadvantage of weight increasing and adhesive joining needs severe control of the materials and requires many tasks on management and workers. In this study, friction stir spot welding (FSSW) technology using thermoplastic adhesive was developed to join CFRP plate and aluminum plate in order to overcome these problems. CFRP plate and aluminum plate were successfully joined by the FSSW and the tensile shear strength of 10.9 MPa was obtained.

Keywords

friction stir spot welding, carbon fiber reinforced plastics, aluminum, thermoplastic adhesive