Pull-off strength of fiber-reinforced composite polymer coatings on aluminum substrate.

The influence of surface roughness on adhesive joint strength for polymer coating reinforced with various fabrics to aluminum substrate was investigated. PA11 aluminum alloy was chosen as the substrate, which was prepared in two different methods: degreasing with acetone or abrasive blasting. Two different abrasives (F80 fused alumina or GH40 cast steel grit) were used for mechanical treatment to obtain different roughness parameters. The coatings were made of two matrices (polyurethane and epoxy resins) and four different reinforcement materials (glass, carbon, aramid, and carbon-aramid hybrid fabrics). The manufactured samples were subjected to roughness and coatings' thickness measurements, wettability evaluation, and pull-off strength tests. Various mechanisms of detachment were observed. The increase in substrate roughness had a positive effect on the pull-off strength. The highest pull-off strength values were obtained for unreinforced polyurethane coating (4.46 MPa) and epoxy resin with glass fabric (3.07 MPa) after pretreatment with abrasive blasting with the use of F80 fused alumina. [ABSTRACT FROM AUTHOR]