Comparative Experimental Investigation of Mechanical Properties and Adhesion of Low Temperature PVD Coated TiO2 Thin Films

Titanium dioxide (TiO2) has been widely used as a biomaterial due to its excellent mechanical and wear resistance properties. In this study, we have deposited TiO2 thin films on stainless steel substrate at low temperature (90 ℃) by middle frequency (MF) magnetron sputtering and cathodic arc PVD techniques at two different substrate surface roughness. Scanning Electron Microscope (SEM) and Energy Dispersive X-ray (EDX) techniques have been utilized for the study of surface morphology and stoichiometric elemental chemical composition of the TiO2 thin films. Scratch adhesion and nano indentation experiments were conducted for the assessment of the film adhesion and mechanical properties of the TiO2 thin films respectively. Results proved that the TiO2 thin film deposited on higher substrate surface roughness (0.7 µm) samples by MF magnetron sputtering PVD process have superior adhesion and mechanical properties. Correlation comparative analysis of the TiO2 thin films deposited by the MF magnetron sputtering PVD process gave the optimum results at 1238 nm film thickness and 0.7 µm substrate surface roughness. The maximum of 14 N adhesion strength, 13.8 GPa hardness and 345.6 GPa elastic modulus values have been recorded.