Fundamental investigations of the temperature-dependent self-organization of PECVD- and PVD-TiSiBCN thin films

• Applicants: Professor Dr. Günter Bräuer; Professor Dr.-Ing. Wolfgang Tillmann
• Subject Area: Coating and Surface Technology
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 434108570

With increasing demands for an enhanced service life time of tools used in the field of hot forming, new and innovative wear protecting coating systems for high process temperatures are mandatory. Hot forming processes like forging or die casting are characterized by cyclic, elevated mechanical loads under high thermal process temperatures with alternating stresses. At the same time, high tribological stresses are generated at the surface of the tools due to the material transfer. In order to maintain an economical production of parts and to further enhance the requirements for the tool surfaces, new coating materials are needed. Nanostructured multiphase coatings, generated from carbides, nitrides, borides or silicides of the transient metal titanium do provide these properties.Currently, coatings consisting of binary or ternary compositions are used to reduce tribologically caused wear. For example, TiN, TiC, TiB2 or TiCN, TiBN are commonly used, yet limited in their thermal properties concerning degradation and oxidation. These coating systems are expected to expand the elements silicon and/or carbon to synthetize quaternary or quinary coating systems, which are utilized under high thermal load conditions (700-1000°C). Preliminary investigations show that these coating systems, produced by PVD or PACVD coating technologies are considered to be very efficient to reduce wear under the given load conditions. It seems as if they are capable to preserve or even optimize their mechanical properties while changing their structural composition in nanoscale dimensions. This proposal aims to investigate the described coating properties with analytical methods in-situ under high thermal loads for differently generated coatings by means of PVD and PECVD techniques. Tribological investigations under laboratory conditions will reveal the benefits of the coatings.At the end of the project, finding will be available that explain how multiple phase coating systems are to be designed to effectively reduce wear for tools used in hot forming applications.

• DFG Programme: Research Grants