Plasma treatments of polymeric materials and Al alloy for adhesive bonding

Cold plasma treatments to modify the surface properties of polymeric materials (polyoxyphenylene-polyammide, polycarbonate-ABS) and Al 6061 alloy, have been performed with the aim of increasing the surface adhesion in structural joints. An experimental cold plasma generator working in flow gas (Ar, O 2, N 2) was employed to obtain a localised treatment. Some conventional surface treatments have been employed to compare the results. Joint strength and morphology fracture analysis of the surfaces were done. Results show that cold plasma treatments with oxygen gas lead to higher shear strength and low data dispersion with high quality of the joint. Morphological analysis reveals the different fracture modes to correlate with the surface treatments.