Effects of surface pre-treatment and void content on GLARE laminate process characteristics

In this paper the effects of surface morphology and voids formed in the metal sheet–prepreg interface of GLARE laminates were evaluated. The experiments were carried out with aluminum sheets on which the surface morphology was systematically varied by different roughness levels of surface textures (sanding and nylon-pad abrasion) and chemical etches. The surface morphology of the substrates was characterized with profilometry and the static contact angle technique. Void contents at the metal sheet–prepreg interfaces were determined by scanning electron microscopy. The changes in surface roughness and surface energy effectively enhance the bonding strength of GLARE laminates. Experimental results also indicate that the autoclave pressure enhances GLARE interfacial bonding, to a certain extent, with low void content.