Preparation and Characterization of Si-Containing Titanium Oxide Film by Micro-Arc Oxidation

Micro-arc oxidation (MAO) has been widely used to surface modified titanium and its alloys for biomedical applications [1,2]. Also, Ca incorporating in the MAO film is beneficial to cell proliferation [3]. In addition, Si containing coating has been demonstrated to improve the cell adhesion [4]. Hence, this study prepared the Si, Ca, P containing electrolyte to fabricate titania films by MAO. Commercial pure titanium (c. p. Ti) coupons (10×10×1 mm) were abraded with silicon carbide paper up to grade 800, cleansed with acetone for 5 min, followed by ethanol for 3 min in an ultrasonic bath, and finally dried at room temperature. The electrolyte contained 0.2M calcium acetate monohydrate (Ca(CH3COO)2·H2O), 0.04M calcium glycerophosphate (C3H7Na2O6P·5H2O), 0.04M Na2(EDTA) and Na2SiO39H2O (0.04 M) as the source of Ca, P and Si for the MAO. Ti plates were micro-arc oxidized at a constant voltage of 300 V for 10 min using a direct current power supply, and a high density graphite plate was used as the cathode. The temperature during MAO was kept by a water cooled bath in a stainless steel tank. After micro-arc oxidized, the samples were rinsed with distilled water and dried in air. The surface morphologies of MAO films were observed using a scanning electron microscope (SEM; Model: PHILIPS XL30). The crystallinity and phase of the AOF were identified via glancing angle X-ray diffraction using a Kα radiation with an incidence angle of 1° and at a scanning speed of 2°/min (XRD; Model: PHILIPS X'Pert, X-ray tube PW3373/100 Cu LFF DK147515).