Enhanced adhesion properties of steel-polymer composites by surface patterning technique

Abstract

The adhesion power between carbon steel and epoxy composite is significantly enhanced by fabricating surface pattern on the carbon steel. The micro-patterns with several tens of features over large-areas were fabricated using photolithography and wet chemical etching on the surface of carbon steel, in which the micro-patterns are accomplished by precisely controlling etching time and concentration of the etchant. The results of adhesion power test show that the adhesion power is strongly influenced by the shape and size of the patterns. We found that square dot patterns on the carbon steel enhanced the adhesion power by 39.6%, compared to conventional methods for example, surface grinding physically with sand paper or fully chemical etching without any regular structure in immersion by acid. To measure adhesion power between the patterned surface of carbon steel and a polymer composite adhered with epoxy adhesive, ENF(End Notched Flexure) test was applied, which can measure the shear stress occurring between two interfaces as a function of displacement. We have applied several micro-patterns having a variety of sizes and morphologies for ENF test. Square dot patterns of them generated the highest enhanced adhesion performance as mentioned above.