MATERIALS CHEMISTRY AND PHYSICS, cilt.303, 2023 (SCI-Expanded)
Commercial pure titanium (Cp-Ti) is widely used in many industrial and biomedical fields. However, depending on the conditions of use of Cp-Ti, it exhibits low wear and corrosion resistance, thus reducing its service life. Therefore, in this study, the cuticle of the Japanese jewel beetle (Chrysochroa rajah) was morphologically examined and duplex coatings were produced by dip coating technique on Cp-Ti to provide protection against wear and corrosion by imitating the layered structure of the Chrysochroa rajah cuticle. Duplex coated surfaces were obtained by dip coating technique with chitin as the first layer and TiO2, SiC and h-BN layers as the second layer, respectively. Electrochemical corrosion properties were investigated under Simulated Body Fluid (SBF) solution. In electrochemical corrosion tests, open circuit potential (OCP), electrochemical polarization and electrochemical impedance spectroscopy (EIS) analysis were performed. Wear tests were performed in dry and SBF solution, and tribocorrosion tests were performed in SBF solution. The chitin + h-BN duplex coated surface has the highest corrosion potential (Ecorr) of-14 mV and the lowest corrosion current density (icorr) of 1.060 x 10-9 A cm-2. In addition, chitin + h-BN duplex coated surface has the highest corrosion resistance among duplex coated surfaces with corrosion rate of 4.601 x 10-4 mpy. In the wear test results, the lowest wear rate was 0.12 +/- 0.011 x 10-3 mm3/Nm in dry environment and 0.28 +/- 0.017 x 10-3 mm3/Nm in SBF solution on chitin + TiO2 duplex coated surface. In addition, the highest surface hardness was obtained as 4 +/- 0.28 GPa on the chitin + TiO2 duplex coated surface. As a result of the tribocorrosion tests performed in SBF solution, the highest resistance was obtained on the chitin + TiO2 duplex coated surface. The chitin layer exhibited low corrosion, wear and tribocorrosion performance. Due to the effect of different electrical charge transfer and different hardness of organic and ceramic powders used in coatings, the coated surfaces improved the electrochemical, abrasion and tribocorrosion properties of Cp-Ti.