Setting of adhesive bonded surface optimum roughness value

Abstract

Bonded joint is a very exacting system. Its quality and failure rate depends on many factors. Basic failures of bonded joints divide in adhesive and cohesive ones. When the breakaway between adhesive lay and bonded material occurs, it is adhesive failure. The presence of oxides and of not quite suitable wetted surface geometry is the reason. By a suitable mechanical pretreatment of a bonded surface the adhesive failure can be hindered. For tests two groups of materials were chosen, namely steel and aluminum alloys. The aim of tests was the evaluation of roughness parameters change of steel, aluminum and duralumin surfaces using different grit of the abrasive cloth. Thanks to different material structure it was possible to determine the different effect of the same abrasives on the integrity of the grinded surface. Comparing the reached strength values the hypothesis was confirmed that the bonded surface mechanical pretreatment is one of key influences on the bonded joint primary strength. The analysis of reached data makes possible the formulation of optimum roughness parameters values with contemporary defining the abrasive cloth type.