Mechanical property and joining characteristics of laser direct joining of CFRP to polyethylene terephthalate

Abstract

This study was performed to investigate the joining possibility and characteristics of the dissimilar joint between carbon fiber reinforced plastics (CFRP) and amorphous polyethylene terephthalate (PET) plastic using a continuous wave (cw) diode laser with a line-shaped beam. Tensile shear test results demonstrated that strong lap joints with a maximum load of 3200 N could be produced under some proper conditions, and base amorphous PET plastic sheet was elongated without fracture. It was confirmed from SEM observation that the dissimilar lap joint was tightly bonded near the joint interface between two materials, and simultaneously integrated by the interdiffusion and mixing process at the joint interface of two materials through rapid melting, solidification and cooling during laser joining. Through high speed video camera observation, the joining phenomena generating in the laser irradiated part during laser joining of CFRP to PET was obviously identified. Consequently, it was revealed that strong dissimilar lap joint of CFRP to engineering plastic could be possible by a direct laser irradiation without adhesive bonds or mechanical fasteners.