The effect of surface treatment on the shear properties of aluminium-polypropylene joints manufactured by laser beam

In this article, we evaluated the mechanical response of laser-joined EN AW-6082 aluminium alloy and polypropylene (PP) specimens under quasi-static and cyclic shear loading. In order to increase the strength of the joints, we formed grooves in the aluminium with laser ablation. We determined the effect of PP melt viscosity and heat generated during the joining process on the shear strength of the joints using three types of PP with different melt viscosities. In order to influence the adhesion between the apolar polypropylene and the aluminium, we also treated some PP specimens with maleic anhydride (MA) prior to joint formation. We found that by doing so, the quasi-static shear strength of the joints increased by 50% on average. Furthermore, when we engraved many grooves in the aluminium and treated the PP specimens with MA, the average failure cycle number of specimens could be increased by an order of magnitude.

Automated summary

In this study, the mechanical response of laser-joined EN AW-6082 aluminium alloy and polypropylene (PP) specimens under quasi-static and cyclic shear loading was evaluated. Grooves were formed in the aluminium using laser ablation to increase the strength of the joints. The effect of PP melt viscosity and heat generated during the joining process on the shear strength of the joints was determined by using three types of PP with different melt viscosities. The adhesion between the apolar polypropylene and the aluminium was influenced by treating some PP specimens with maleic anhydride (MA) prior to joint formation. It was found that by doing so, the quasi-static shear strength of the joints increased by 50% on average, and the average failure cycle number of specimens could be increased by an order of magnitude when engraved grooves were combined with MA-treated PP specimens.