Synthesis and characterization of high-voltage electrodeposited diamond-like carbon protective coating on TiAlV biomedical substrates

摘要

Diamond-like carbon films (DLC) were deposited on TiAlV alloy substrates in liquid methanol by the liquid-phase electrodeposition technique in nitrogen atmosphere at room temperature. The voltage applied between the electrodes was higher than 1800 V because of the use of resistive organic liquid. The electrochemical behavior of TiAlV and DLC-covered TiAlV samples was investigated in fetal bovine serum at 37 °C and atmospheric pressure without agitation, using electrochemical impedance spectroscopy and potentiodynamic polarization as electrochemical techniques. For surface characterization techniques, we used scanning electron microscopy, X-ray diffraction, and Vickers microhardness measurements. Raman spectroscopy analysis of the films revealed three broad bands at approximately 1227, 1356, and 1550 cm ~(-1) related to possible diamond nanoparticles, to TiC or amorphous TiO _x, and to D- and G-bands of DLC, respectively. The metallic ion release in bulk solution was studied by inductive coupling plasma-mass spectrometry. In uncoated samples, the release of metallic ions in bulk solution was much higher than in DLC-coated samples. Also, the corrosion resistance and Vickers microhardness of DLC-coated samples were improved in comparison with the uncoated samples.