ADVANTAGES AND LIMITATIONS OF LASER TRANSMISSION WELDING FOR HIGH PERFORMANCE COMPOSITES

摘要

Due to their superior specific strength and stiffness properties, continuous carbon fibrernreinforced thermoplastics (TPC) are becoming more important in many industrial applications. Inrnorder to cope with rising production volumes, automatable and flexible production processes,rne.g. joining techniques, are desired. Due to its local energy input and its high flexibility, laserrntransmission welding (LTW) is regarded as an acceptable industrial process for the joining ofrnunreinforced thermoplastics. By enhancing this technology with respect to a realization of arnwelding process based on continuous carbon fibre reinforcements, the full benefits of weldingrnconventional thermoplastics could be transferred to this novel material category. Hence, thernsubject of the work presented here is to generate fundamental process knowledge concerning arnpotential use of TPC as laser absorbing part within the frame of LTW processes. Significantrndifferences to the process characteristics encountered during the joining of unreinforcedrnthermoplastics emerge from the carbon fibre reinforcement, inducing high thermal conductivityrnand fluctuating absorption properties for the laser wavelength. This results in an essentiallyrnaltered plastification performance, which is directly mirrored in the weld seam structure.rnCorrespondingly, actions for an enhancement of the process reliability are presented.