Quality Controlled Induction Welding by Adapted Process Parameters

摘要

In this paper the continuous induction welding of carbon textile reinforced thermoplastics is introduced and investigated regarding optimized process parameters and quality control. The resulting overall bonding quality of welded joints shows the capability to replace other mechanical joining methods like bolts. Therefore, the process has a high potential for the aerospace as well as the automotive industry. During induction welding, the heating of the material is generated by induced eddy currents and joule losses. Due to their electrical conductivity, carbon fiber reinforced thermoplastic composites can be inherently heated. To prevent delamination (void growth) of the laminate, the part surface is cooled by an air jet. To implement a quality controlled, automated welding process the surface temperature is monitored and a thermal simulation is used to calculate the temperature in the joining area. The thermal simulation model is explained and process diagrams are calculated. These process diagrams can easily be changed by a user interface. For different welding speeds, optimum coil settings are found to gain bonding strength at autoclave quality with high welding speed and reproducibility. Overlap specimens were produced and tested to verify the simulated optimum parameters and to show the capability of the quality control concept.