When manufacturing joints of dissimilar materials thermal technologies as welding reach their limits. Impact welding by electromagnetic forming is a promising alternative because undesired heating of the parts and related disadvantages are avoided. In this process impact parameters need to be adjusted to each specific joining task, but cannot be settled directly. Thus, a two-step methodology is suggested for the process design: First the influence of the impact parameters and the surface preparation on the joint properties is investigated using a model experiment. Joint properties are characterized by metallographic investigations. Parallel to this, the influence of the adjustable process parameters and the equipment on the workpiece acceleration and the impact properties is analyzed. Then the results of both investigation paths are combined and conclusions regarding a target-oriented adjusting of the impact parameters via the process parameters are drawn. In the paper first results considering the model experiment and the analysis of the electromagnetic expansion process are presented and joints manufactured by electromagnetic expansion are characterized.