Abstract
The effect of cobalt on enamel reaction was studied using Co-vitreous enamel. Observation and analysis of Co-vitreous enamel interface were performed with scanning electron microscope, X-ray photoelectron spectrometer and X-ray diffractometer. The following results were obtained. (1) The sunken parts of Co-vitreous enamel interface were formed by erosion of the base iron. Cobalt and iron deposited on the base iron and formed convex parts. Further, the convex parts grew by firing from the initial interface towards the glass (enamel layer) side. (2) Interface layer of Co-vitreous enamel was consisted of two layers. The first interface layer was very thin and consisted of CoFe2O4 or FeFe2O4. The second interface layer was the iron solid solution containing cobalt. The thickness of Co-vitreous enamel reaction layer was thicker than the rough parts. (3) The Co-vitreous enamel reaction was a galvanic cell reaction between base iron and cobalt ion in glass. Cobalt circulate by reaction as deposition, oxidation and dissolution.
