Surface treatment of CFRP composites by Ar+ irradiation to improve bonding strength between aluminum and CFRP composites

Abstract

he effect of surface treatment of carbon fiber reinforced plastic (CFRP) composites on the T-peel strength and the shear strength between CFRP and aluminum panels was studied. The surface of the composite panel was treated with Ar^sup +^ irradiation under oxygen environment. The optimal Ar^sup +^ ion dose was determined by measuring the changes of contact angle and surface energy as a function of ion dose. T-peel tests and SIS tests were performed using irradiated CFRP/aluminum specimens and unirradiated CFRP/aluminum specimens to determine the treatment effect by Ar^sup + ^ irradiation under oxygen environment on the T-peel strength and shear strength of CFRP/aluminum composites. The results showed that contact angle on the surface of the composite panel was reduced from ~80 to ~8 deg and the surface energy increased from 31 ergs/cm^sup 2^ to 72.4 ergs/cm with an ion dose of 10^sup 17^ ions/cm^sup 2^. T-peel strength and shear strength are significantly affected by the surface treatment of composite panel. T-peel strength and shear strength improved 650% and 56%, respectively, when the treatment was made with an ion dose of 10^sup 16^ ions/cm^sup 2^. SEM examination showed that the improvement of bonding strength was attributed to the uniform spread and fracture of epoxy adhesive.