Continuous ultrasonic welding of carbon fiber-reinforced polyamide 12 unidirectional tape to polyamide 12 substrates fabricated by laser beam powder bed fusion

Ultrasonic welding offers considerable potential to replace conventional adhesive or thermal bonding techniques. This study investigates a hybrid process combining laser beam powder bed fusion and continuous fiber reinforcement. After printing, the laser beam powder bed fusion substrate is reinforced with a composite tape on the outer surface using continuous ultrasonic welding. The quality of the joint weld is analysed based on the lap shear strength between the joining partners. The results show a maximum lap shear strength of approximately 21.4 MPa. Compared with other continuous fiber 3D printing / additive manufacturing technologies, ultrasonic welding can achieve lap shear strength values that are 45 to 104 % higher. The results indicate that the optimal parameter window for this process-material combination is achieved at a lower welding speed, a sonotrode amplitude of 27 μm and a welding pressure of approximately 0.5 MPa.