Study on Morphologies and Structures of Ceramic Coating Prepared by Micro-Arc Oxidation on TC4 Alloy in Different Electrolytes

摘要

In this work, the effects of concentration and mixture ratio of Ca(CH_3COO)_2·H_2O and Na_5P_3O_(10) in electrolyte on surface morphology, and phase structure of ceramic coating prepared by micro-arc oxidation (MAO) on TC4 titanium alloy were studied. A suitable formula of electrolyte for bio-modification of titanium by MAO was obtained namely, Ca(CH_3COO)_2·H_2O 20g/L and Na_5P_3O_(10) 9.3g/L. Using this electrolyte with appropriate process conditions, the ceramic coating was prepared with porous structure and combined well with the substrate. Scanning electron microscope (SEM) equipped with the energy dispersive spectrometry (EDS) was used for observation and evaluation of the morphology. The pores distributed equably on the surface of ceramic coating and the size of pores was in micron order. The ceramic coating was composed of titanium dioxide in different crystal types which have been characterized by the X-ray diffraction (XRD). The anatase titanium dioxide was a major component.