LAUSR

To protect forming tools and components from abrasion, adhesion and corrosion, the application of thin hard coatings by physical vapor deposition is state-of-the-art. The use of a hybrid coating technology, consisting of high power pulse magnetron sputtering (HPPMS) and direct current Magnetron Sputtering (dcMS), allows a combination of the advantageous properties of both. HPPMS coatings for examples show a dense morphology, high hardness and smooth surface. Using dcMS, higher deposition rates can be achieved, resulting in a higher economic efficiently. Within the scope of this work, a novel multilayer coating concept of the material system Ti–Al–O–N was developed. The coatings were deposited using an industrial coating unit. Cold work steel X42Cr13 was used as substrate material. The coatings consist of a metallic titanium bond coat and a nitride TiN/AlN nanolayer as an interlayer. The nanolayer coating architecture leads to a dense, compact and fine crystalline morphology with smooth surfaces. Finally, an oxynitride toplayer with two different oxygen contents was applied. In order to investigate the coating durability relevant for polycarbonate melt processing, electrochemical impedance spectroscopy and linear sweep voltammetry were carried out in borate buffer, NaClO4 and benzoic acid electrolyte. An increased oxygen content in the oxynitride toplayer led to a decreased interfacial current density.