Properties of TiAlCN/VCN Nanoscale Multilayer Coatings Deposited by Mixed High-Power Impulse Magnetron Sputtering (HiPIMS) and Unbalanced Magnetron Sputtering Processes—Impact of HiPIMS During Coating

Nanoscale multilayer TiAlCN/VCN coating has been deposited by pure unbalanced magnetron sputtering (UBM) and high-power impulse magnetron sputtering (HiPIMS)-UBM techniques. The V
⁺
HiPIMS etching used in both processes has shown excellent adhesion (Lc > 50) of the coating to the substrate. The plasma compositional analysis of V
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HiPIMS etching has shown high metal-to-gas ion ratio with ionization states of V up to 5+. Moreover, during the coating of TiAlCN/VCN, the plasma analysis has confirmed the higher production rate of metal ions in the case of HiPIMS-UBM in contrast to pure UBM. This has resulted to a denser closed columnar microstructure of the coating during the HiPIMS-UBM technique than UBM. A thermogravimetric analysis has shown increased oxidation-resistance temperature for coatings deposited by HiPIMS-UBM (w780°C) with significantly lower mass gain. The scanning electron microscope and X-ray diffraction studies of the oxidized surface of the coating have revealed the formation of lubricant Magneli phase oxides of V
₂
O
₅
and TiO
₂
at elevated temperature. The wear coefficient of the coating deposited by HiPIMS-UBM has shown two orders of magnitude lower value than that for the UBM-deposited coatings, which represents significant advantage for coatings deposited by UBM. This enhanced performance in oxidation-resistance dry sliding wear conditions can be attributed to the extremely dense structure of the HiPIMS coatings, which could be promising in elevated temperature applications.