Laser joining of endless long fiber reinforced thermoplastics with aluminum Available to Purchase

The ongoing efforts in the field of light weight design lead to a hybridization of engineering constructions which are currently dominated by metallic materials. Because of their advantageous strength to mass ratio plastics and especially fiber reinforced plastics have a high potential as light weight design material. However, metals will not be substituted completely because of technical and economic reasons, which leads to the challenge to join these dissimilar materials in order to further decrease the mass of light weight constructions. The investigations presented in this paper show the possibility to join endless long fiber reinforced thermoplastics with 6xxx - series aluminum. As plastic joining partner glass fiber reinforced PA6, PA66 and PP is used. In order to investigate the strength of the joint for different types of stress, tensile shear strength, pealing tension and fatigue strength tests were performed. The results of the experiments show separation forces up to 6.5 kN using PA6 as matrix material. Trials carried out with the matrix material PP showed significantly lower separation forces of 2 kN in a maximum. The process investigation showed a strong correlation between the process parameters laser power and feed rate and the separation force achieved. This leads to the conclusion that the joining temperature has to be adjusted carefully to the properties of the matrix material since it can be considered that it is mostly responsible for the formation of the joint.