The effect of surface pretreatment on carbon fibre–polyimide matrix composite bonding

Abstract

The single lap shear test and the wedge test were used to evaluate the effect of surface pretreatment on the strength and durability of adhesively bonded composite joints. Both types of joints were placed in three different environments: (1) room temperature, desiccator, lo00 h; (2) 204 "C, lo00 h; (3) immersion in boiling water for 3 days for the single lap shear test and until failure for the wedge test. The failure surfaces were analyzed using XPS to determine the locus of failure. An oxygen plasma was found to be the best pretreatment. The improvement in adhesive bonding following exposure to an oxygen plasma in comparison to the other surface pretreatments was attributed to several factoreduction in fluorocarbon contamination and an increase in oxygen surface functionality. This increased surface functionality and decrease in fluorocarbon contamination caused better wetting of the composite surface and also may lead to covalent bonding at the composite/primer interface.

How variability in interfacial properties results in tougher bonded composite joints by triggering bridging

“…Different techniques are developed to pretreat a substrate, such as peel-ply preparation, grit blasting, etching, laser treatment, plasma treatment etc . Different trends in the toughening effects for different surface treatments and different enhanced performances of bonded FRP joints were demonstrated ( Moyer and Wightman, 1991 ). Recently, the most commonly used pretreatment techniques, i .…”