Suitability of thickness change as process control parameter for induction welding of steel/TP-FRPC joints

Abstract

This study examines the influence of thickness change on bond strength of welded hybrid joints of physically surface-treated steel sheets and glass fiber reinforced polyamide 6. The quasi-static, discontinuous induction welding was used as joining method. The steel sheets were either treated by a parallel line shaped laser structuring, which is perpendicular to the load direction and has a line distance of 0.3 mm or 0.6 mm or by a compressed air blasting. Furthermore, the influence of joining temperature on bond strength was examined as a comparison. In both cases bond strength was determined using tensile shear tests according to DIN 1465. In addition, the void content in the laminate and in the joining zone was investigated by cross section images. A time-temperature-thickness change diagram was developed to gain insight into the processes during welding. Based on these findings, it can be stated that thickness change is suitable for process control and as a quality assurance feature in hybrid induction welding.

Keywords

• induction welding
• lap shear strength
• hybrid joining
• influence thickness change
• process control
• thickness change curve
• surface treatment