Comparison of the structure and properties of the PVD and CVD coatings deposited on nitride tool ceramics

Comprehensive structure and properties investigation results of the multi-layer, multi-component physical vapour deposition (PVD) and chemical vapour deposition (CVD) coatings developed on the Si3N4 nitride tool ceramics substrate are presented in the paper. The detailed results are presented of examinations carried out on the scanning and transmission electron microscopes, as well as of the mechanical properties and tribological tests of the investigated coatings. Examinations of the chemical compositions of the deposited coatings were also carried out using the X-ray energy dispersive spectrograph EDS, glow-discharge optical emission spectroscope GDOS, and using the X-ray diffractometer. Machining tests of the grey cast iron and nickel alloy were made to analyse in detail the investigated multi-edge cutting inserts. The inserts made from Si3N4 were coated in the PVD process with the TiN + multiTiAlSiN + TiN, TiN + TiAlSiN + TiN, TiN + TiAlSiN + AlSiTiN type multi-component coatings and in the CVD process with the coatings based on the combination of the TiC, TiN, Ti(C,N) and Al2O3 layers.