Investigating the suitability of roughness parameters to assess the bond strength of polymer-metal hybrid structures with mechanical adhesion

The joining of distinct incompatible materials, like metals and polymers or fiber-reinforced polymers, is gaining in importance, especially for lightweight applications. Here, it is advantageous if the materials can be joined during the manufacturing of the hybrid component. Besides conventional technologies, like over-molding or the use of adhesive bonds, the use of micro structures is a promising approach for in-mold assembly. However, the characterization of these micro structures to assess the bond strength is difficult, especially for a load perpendicular to the joining surface. This paper deals with the assessment of the bond strength of polymer-metal hybrid structures with micro-structured metal inserts by the use of roughness parameters. The micro structures were produced by electrochemical treatments.