Nanomechanical properties and nanotribology of ternary metal nitrides nanocomposite

Ternary metal nitride nanocomposite thin films have great potential as hard protective coatings for applications where high hardness, good wear resistance, high corrosion resistance and low surface roughness are required. The aim of the present research was to investigate nanocomposite thin films of Metal-BN and Metal-ZrN types (e.g. Cr-BN, Ti-BN, Cr-ZrN, Nb-ZrN and Inconel-ZrN), to explore their deposition conditions, nanomechanical properties and nanotribological behavior. Ternary metal nitride nanocomposite thin films were produced by DC unbalanced magnetron sputtering. Nanomechanical and nanotribological properties of thin films were characterized using a Hysistron Triboscope in conjunction with an atomic force microscope. The study aims to provide a better understanding of the correlation between static nanomechanical properties (nanohardness (H), elastic modulus (E), H/E and H3/E2 ratio) and dynamic properties (resulting from nanoscratch and nanowear measurements) for three groups of Metal-ZrN thin films (Inconel-ZrN, Cr-ZrN and Nb-ZrN) and monolayer polycrystalline ZrN thin films. It was demonstrated for the first time that elastic recovery after nanoscratching may be a better predictor of wear-resistance than conventional static nanoindentation testing, H/E and H3/E2 ratio evaluations that are currently used in the area of thin films, especially wear coatings. In order to predict the best ternary metal nitride thin film compositions for abrasive wear resistant applications (dry and lubricated contacts), the nanotribological performances for three groups of Metal-ZrN: Inconel-ZrN, Cr-ZrN, Nb-ZrN and ZrN thin films have been correlated with surface energy evaluation. Additionally, the chemical composition and microstructure of Me-BN and Me-ZrN thin films were investigated using X-ray diffraction, X-ray photoelectron spectroscopy and Auger electron spectroscopy, as well as analyzing their optical properties using spectroscopic ellipsometry. The chemical composition was correlated with nanomechanical and nanotribological properties. Nanoindentation, nanoscratch and nanowear evaluations showed that ternary metal nitride thin films have superior properties compared to classical binary polycrystalline thin films. Nanotribological evaluations can bring additional information to light regarding thin film behavior under combined normal and lateral forces, and therefore could be a better predictor for wear behavior