Schlü sselworte: Duplex-Prozess, Druckguss, nano-structure, nano-composite, Gradientenschicht Duplex-PACVD hard coatings are well-known for increasing the tool performance in terms of adhesion, wear, fatigue, and corrosion resistance of the steel.The developments made in synthesizing duplex nanostructure and nanocomposite, mono and gradient layers based on borides are described. The aim of the investigation is to optimize the surface capability by plasma process combinations: duplex process, gradient-layer.Within this work different types of duplex hard coatings produced by PACVD were investigated in terms of their tribological behavior and were tested in aluminum and magnesium die casting applications.Practical tests have been carried out by automobile producers and part suppliers.All coatings tested on die casting tools showed a significant increase of lifetime and a reduced metal adhesion tendency. The economic efficiency of coated die casting tools could be proved.