Deposition and characterization of Ti-Al-C-N coatings

In the present work, Ti-Al-C-N coatings were deposited on cemented carbide substrates by lateral rotating cathodes (LARC (R)) process using Platit pi(80)+DLC deposition unit. The effect of C2H2 gas flow rate on elemental and phase composition, deposition rate, cross-sectional and surface morphology, mechanical and tribological properties of the coatings was studied. Following analytical techniques, namely: scanning electron microscopy (SEM) with energy and wave dispersive X-ray spectroscopy (EDS and WDS), X-ray diffraction analysis (XRD), nanoindentation measurements, Rockwell C indentation test and tribological testing were used for Ti-Al-C-N coatings evaluation. From the EDS analysis, it was found that the carbon content in the coatings increased from 0 at.% to 22.3 at.% as the C2H2 gas flow rate increased from 0 sccm to 75 sccm. The increase in deposition rate of coatings from 0.029 mu m/min to 0.052 mu m/min was documented. From XRD results it was found that the coatings consist of a cubic B1-NaCl type Ti1N0.9 phase. The maximum hardness was observed at C2H2 gas flow rate of 25 sccm and the lowest friction coefficient (0.35) at the maximum C2H2 gas flow rate. The coatings deposited at C2H2 gas flow rates (25 sccm and 50 sccm) exhibited an excellent adhesion.