Improved mechanical properties of resistance welded joints of thermoplastic composites by versatile graphene oxide

Abstract

An approach of adding graphene oxide (GO) nanosheets to enhance the joints for resistance welding glass fabric reinforced polyetherimide (GF/PEI) laminates was proposed in this study. The GO nanosheets were introduced and dispersed uniformly into the heating element (HE) of carbon fiber (CF) bundles coated PEI and the welding adhesives of PEI films in the different weight ratios. The GO nanosheets were prepared firstly by the modified Hummers method. Then their morphology and structure were also confirmed by the combination of a scanning electron microscope, Fourier transform infrared spectrometer, X-ray diffraction and Raman spectrometer. The lap shear strength (LSS) obtained from single lap shear specimens and fracture morphology are reported to evaluate the optimum welding parameters, such as input power, heating time and pressure. Finally, the effect of GO on the LSS of the welded samples was studied. The results showed that the LSS of joints was increased by adding GO to the welded joint, but if it exceeded the optimal value, they were more vulnerable to damage.