Abstract
Observation of the enameles interface with SEM, EPMA and ESCA, and measurement of adhesive strength of the enameles were done. Simultaneously, cobalt and nickel in the enamel layer examined a given influence at the interface and the adhesive strength. As a result, the relationship between iron-oxygen, cobalt-oxygen and nickel-oxygen, at the reaction of enamel process was explained by the interface thermodynamics. Furthermore, characteristics and differences of reaction of cobalt and nickel were clarified. (1) The adhesive ability of Co-enamel was larger than that of Ni-enamel. (2) The adhesive behavior of cobalt changes at about 730°C, but that of nickel remains unchanges. Consequently, cobalt has an adhesion with the high temperature (over 730°C) but nickel does not have an influence on the temperature. (3) At high firing temperature, the Co-enamel can create FeO easily compared with Ni-enamel, and dissolve Fe2O3 of steel surface into glass. (4) Cobalt spreads for a vertical direction of interface, but nickel tends deposition on the interface surface. And the diffusion capability of cobalt into the steel was considerably greater than that of nickel.
