Chemical vapor deposited TiCN/TiC multilayer coatings: On the interplay between coating architecture and mechanical properties
Christina Kainz, Michael Tkadletz, Verena Maier‐Kiener, Bernhard Völker, Michael Burtscher, Helene Waldl, Maximilian Schiester, Josef Thurner, Christoph Czettl, Nina Schalk
Abstract
Modifying the architecture from a monolithic to a multilayered structure allows adjusting the mechanical properties and cutting performance of industrially relevant hard coatings. The present work focuses on the microstructural, micro-mechanical and cutting performance evaluation of a multilayered TiC 0.67 N 0.33 /TiC coating grown by chemical vapor deposition. Energy dispersive X-ray spectroscopy and atom probe tomography confirmed the presence of individual TiC and TiC 0.67 N 0.33 layers of ∼120 nm thickness with well-defined interfaces. The overall C/(C + N) ratio of the coating amounts to 0.82. Individual peaks for the TiC 0.67 N 0.33 and the TiC layer can be observed in the X-ray diffractogram of the TiCN/TiC coating. Scanning electron microscopy showed that the grains grow through the interfaces between the TiCN and TiC layers. Finally, the micro-mechanical properties and cutting performance of the TiCN/TiC multilayer were compared with a monolithic TiCN coating. The fact that the TiCN/TiC coating outperformed the monolithic reference TiCN in regard of hardness and cutting performance emphasizes the high potential of multilayered coatings for use in demanding applications. • TiCN/TiC multilayer coating with layer thickness of 120 nm grown by CVD. • Increased overall C/(C + N) ratio as compared to state-of-the-art CVD TiCN coatings. • Better hardness and cutting performance in multilayer as compared to reference TiCN.