Anodic Oxidation of Titanium in Mixture of β-Glycerophosphate (β-GP) and Calcium Acetate (CA)
Anodic oxidation is an electrochemical method for the production of a ceramic film on a metallic substrate. It involves the use of an electrical bias at relatively low currents while the substrate is immersed in a weak organic acid bath. The films produced are usually dense and stable, with variable microstructural features. In the present work, ceramic films of the anatase and rutile polymorphs of TiO2 were formed on high-purity Ti foil (50 μm) using mixtures of β-glycerophosphate disodium salt pentahydrate (β-GP) and calcium acetate monohydrate (CA) solutions. The experiments were carried out at varying voltages (150-350 V), times (1-10 min), and current density (10 mA.cm-2) at room temperature. The ceramic films were characterised using digital photography, glancing angle X-ray diffraction (GAXRD), and field emission scanning electron microscopy (FESEM). The thicknesses of the films on Ti were measured using focused ion beam (FIB) milling. The colour, microstructures, and thicknesses of the films were seen to be strongly dependent on the applied voltage. At bias <200 V, single-phase anatase was observed to form on Ti, while at higher bias (250 V), rutile formed due to the arcing process.
Mohd Mustafa Al Bakri Abdullah, Liyana Jamaludin, Alida Abdullah, Rafiza Abd Razak and Kamarudin Hussin
H. Z. Abdullah et al., "Anodic Oxidation of Titanium in Mixture of β-Glycerophosphate (β-GP) and Calcium Acetate (CA)", Key Engineering Materials, Vols. 594-595, pp. 275-280, 2014