Influence of epoxy resin curing systems and aluminium surface modification on selected properties of adhesive joints

The aim of the present study was to investigate the effect of epoxy resin curing agents and aluminium surface modification on the properties of adhesive joints which were subjected to aging under thermal shock conditions. Composites containing reinforced aramid and carbon fibres with aluminium flat profiles (alloy Al 5754) were tested under shear conditions. Epoxy resin (Araldite LY 1564) with amine curing agents (Aradur 3486, Aradur 3487 and Aradur 3405) was used as a matrix. Composites were made using vacuum-assisted contact lamination. The degree of degradation was assessed on the basis of lap shear strength of adhesive joints in accordance with EN ISO 1465:2009. The research showed that epoxy composite samples based on Aradur 3405 (accelerated aliphatic polyamine) and sanded surface of aluminium presented the best lap shear adhesive strength, because this composite has the largest roughness. The hardness of the used adhesive is slightly increased with the cycle number.