Nanocomposite PVD Coatings Applied to Cold Plastic Forming Tools
Cold forging tools most often fail as a result of wearing down surface layer which works with forming part. Deposition of a hard coating on the working surface is widely applied to increase tool durability. In this respect technologies of production of top layers with the use of nanocomposite materials provide great opportunities of modification of tribological properties. This paper presents results of metallographic, SEM and HRTEM analysis of PVD nanocomposite coatings  (nACVIc, TiCN-CBC and TiCN-NP-MOVIC). The tribological tests with ball on disc (T10) tester and industrial tests of forging tool durability were made. The multilayer nACVIc coating is composed of thin layers with the thickness of approximately 2nm as structured alternately by Al and Ti,N,Si atoms, that is different from TiCN-CBC coating with column structure. A modification of the structure results in change of tribological behavior. The nACVIc nanocomposite coating is characterized by significantly less value of the friction coefficient (0.2) as compared to TiCN-CBC coating (0.7) under the same test conditions.
J. Borowski et al., "Nanocomposite PVD Coatings Applied to Cold Plastic Forming Tools", Materials Science Forum, Vol. 674, pp. 105-112, 2011