Research progress in joining of carbon fiber-reinforced polymer composites and aluminum/magnesium alloys

The lightweight of vehicles is one of the important means to solve the energy crisis and environmental problems, which has been paid great attention by scholars at home and abroad. Carbon fiber-reinforced polymer (CFRP) composites and light alloys such as aluminum and magnesium alloys have a series of excellent mechanical properties and processing performance, representing lightweight materials with great application prospects. It has become a hot research topic to realize the effective joining between the CFRP and aluminum/magnesium alloys which are the promising lightweight materials. However, due to the significant differences in physical and chemical properties between these dissimilar materials, the mixed application of a variety of lightweight materials in the production process is still facing great challenges. The research progress, advantages and disadvantages, and development trend of bonding, mechanical fastening, friction stir welding and its variants were summarized and analyzed. The micro morphology of joints obtained under different bonding methods was investigated. Three mechanisms of friction stir joining between CFRP and aluminum/magnesium light alloys were preliminarily summarized through investigating the micro morphology of joints, including macro anchoring, micro mechanical chimerism and chemical bonding. Finally, based on the above joining mechanism, it is pointed out that the key to further improving the performance of hybrid joints is to increase the surface roughness of the base metal, increase the area of the molten polymer and adopt the hybrid joining techniques.