A method for joining of at least two materials, non-weldable directly to each other with thermal joining processes in a lap joint configuration includes a two step sequence including a first step to apply a thermomechanical or mechanical surface protection layer on the surface of a (stainless) steel substrate and a second step where, a thermal joining process is used to weld the sprayed layer with an applied aluminum sheet without having brittle intermetallic phases in the whole material configuration.