Effect of temperature and deposition technology on the microstructure, chemistry and tribo-mechanical characteristics of Ti-B based thin films by magnetron sputtering

This study deals with a deep investigation on chemical, structural, mechanical and tribological properties of TiBx coatings produced by means of PVD techniques, i.e. Direct Current (DC-MS) and High Power Impulse Magnetron Sputtering (HiPIMS). TiBx coatings were deposited onto Si wafer, at different substrate temperatures (200, 300 and 400 degrees C). DC-MS products were strongly overstoichiometric (B at.%/Ti at.% up to 2.86 +/- 0.01 at 200 degrees C), while HiPIMS ones showed a B/Ti atomic ratio closed to 2, particularly at high temperature. Moreover, HiPIMS films exhibited a dense and almost featureless morphology. All the deposited films were constituted of one crystalline TiB2 phase with hexagonal structure, but in HiPIMS mode, a completely dominant (001) texture was developed, which could be responsible of superior mechanical properties and low wear rates, compared to DC-MS products. Different wear mechanisms, i.e. micro-peeling vs direct ploughing at low abrasion rate have been speculated for the two coating types.

Automated summary

This study investigates the chemical, structural, mechanical, and tribological properties of TiBx coatings produced by PVD techniques. The DC-MS coatings were overstochiometric, while HiPIMS coatings showed a nearly 2 atomic ratio. Both types of coatings were composed of a crystalline TiB2 phase, but HiPIMS exhibited a dominant (001) texture.