Metal and plastic connections are created by pressing or back injection molding a pre-structured metallic mating part with the plastic. The laser plays a decisive role in this process. It creates microstructures in the metallic mating part with undercuts which facilitate the plastic gripping into the metallic surface. The high intensity of the laser radiation causes some of the metal to evaporate. Due to the emerging sublimation pressure, the melt is pressed against the structure edge by the substrate where the melt solidifies. An undercut is formed by multiple repetition. A connection is achieved in the subsequent joining process with the plastic partner by gripping into the microstructure.
The actual joining process is performed by heating up the metal and melting the plastic via heat conduction. The plastic is pressed or injected into the microstructure and solidifies. TRUMPF is involved in publicly funded projects, such as ExraLight or Q-PRO, for the development of a quality-assured production process for multi-material lightweight technology which is compatible for large-scale production.
