Fracture Characteristics of The Laser Bonding Joint Between The Aluminum Alloy and The CFRTP With Preset Aluminum Alloy Sheet

Abstract

Abstract This paper presents a method to improve the laser joint strength between carbon fiber reinforced thermoplastic composite (CFRTP) and aluminum alloy. In this method, the aluminum alloy sheet is preset between the polyetheretherketone (PEEK) and carbon cloth, while the CFRTP with preset aluminum alloy sheet is attained by the compression molding method. The CFRTP with preset aluminum alloy sheet is connected to the aluminum alloy by laser heat source, and the maximum load of the joint can reach 4264 N. Microstructure and fracture surface morphology of joint are observed and analyzed. The results indicate that the element diffusion between the preset aluminum alloy sheet and CFRTP shows more significant compared with the interface of aluminum alloy and CFRTP due to the effect of hot pressing. The fracture failure mode of the lap structure between aluminum alloy and CFRTP is mixed fracture with adhesion fracture as the main component. The fracture position of preset aluminum alloy sheet and aluminum alloy lap structure occurs near the weld seam fusion line, while the fracture behavior presents a ductile fracture. The joint bonding force is mainly attributed to the collective effect of two lap structures, during the stretching process, the interface between aluminum alloy and CFRTP first undergoes fracture, then preset aluminum alloy sheet undergoes plastic fracture failure.