SAE International Study of Bending Strength for Aluminum Reinforced with Epoxy Composite 2016-01-0516

Fiber reinforced composite-metal hybrids are of great interest in automotive industry because of their excellent mechanical properties and light-weighting potential. Adhesive bonding is a preferred joining technique for manufacturing fiber reinforced composite metal hybrids. Metal surface due to the presence of process contaminants (oil, dirt, oxide layer etc.) is difficult to bond. The surface prior to adhesive application needs to be cleaned or modified using surface pretreatment methods. Especially for adhesive bonding of multimaterial joining, surface treatment is a very important step. In this paper, 7xxx series extruded aluminum alloy surface was treated using different conventional surface treatment methods and bonded with glass fiber reinforced epoxy tape/mat (FRP). The intent is to stiffen aluminum with lightweight FRP for energy absorbing part application. The treated surface was characterized using water contact angle measurement for surface energy, optical profilometry for surface roughness, SEM for surface features and Auger electron spectroscopy for chemical analysis of surface. The adhesion strength between Aluminum and continuous glass fiber reinforced epoxy mat was evaluated by lap shear test. The bending strength of aluminum reinforced with epoxy composite was also evaluated to understand the relation between bonding mechanism and mechanical properties. We observed that surface treatment improves adhesion between aluminum and the epoxy composite and thereby results in higher mechanical properties and energy absorption.