Carbon fiber reinforced thermoplastic composites and TC4 alloy laser assisted joining with the metal surface laser plastic-covered method

The carbon fiber reinforced thermoplastic composites (CFRTP) and the TC4 alloy are the main materials for aircrafts lightweight manufacturing. The joining quality between them determines the fatigue life of CFRTP-TC4 hybrid structures. To improve the joining quality between the CFRTP and the TC4 alloy, a metal surface laser plastic-covered method was proposed, and a high-speed laser rotational welding technology was applied. The joint strength, the fatigue resistance and the failure mechanism of the joint were investigated. The result showed that the shear strength and the fatigue resistance of the CFRTP-TC4 joint can be improved significantly and a laser harden layer was produced on the TC4 surface. The joint failure fracture was occurred at the interlayer of CFRTP, which indicates that the joint strength is higher than the interlayer bonding strength of CFRTP. [Display omitted] •A metal surface laser plastic-covered method was proposed in CFRTP-TC4 laser joining.•A high-speed laser rotational welding technology was applied to reduce thermal defects of CFRTP-TC4 hybrid joint.•With this joining method, the CFRTP-TC4 joint fracture mode is the CFRTP interlaminar tearing.