KRUM Stanislav Czech Technical University in Prague

Spoluautoři PEŠLOVÁ Františka, PUCHNIN Maxim, ANISIMOV Evgenyi, HORNÍK Jakub

The paper deals with evaluation of PVD coatings based on functionally graded Cr-Al-N, TiN and Ti-Al-N. Coatings were prepared in the following combinations: CrAl/CrAlN, Cr/CrN/CrAlN, nitriding/Cr/CrN/, CrAlN, nitriding/TiN, AlTiN, nitriding/AlTi/AlTiN. As main criteria for coatings properties comparison were selected methods of scratch test and nanohardness measurement. Subsequently, coatings CrAlN and TiN were designed as protection against high temperature oxidation of Cr-Ni steel (X16CrNiSi25-20) exposed to the temperature of 850 °C for 6 and 12 hours duration. Microstructural analysis of the interface coating - substrate including EDS microanalysis of the elements distribution in the coating and the substrate was performed. Scratch test of selected coating adhesion after heat exposure was carried out. From simulated tests it is evident that PVD coating CrAlN fulfils the role of protection. In the case of TiN there occurred intensive subsurface degradation of the coating connected with decohesion and subsequent cracking of the coating.