DEVELOPMENT AND CHARACTERIZATION OF NEW ART AND DECORATIVE ENAMELS

The application of enamels on metals has many advantages as improving chemical, corrosion, antibacterial resistance and artistic and aesthetic value. The enamel and the substrate must have good adhesion and close coefficients of thermal expansion. In this study, new enamels based on glasses with a melting temperature of up to 1150°C for jewelry brass-coated steel and copper plates were developed. The theoretical properties as the coefficient of thermal expansion, firing temperature, density, compressive strength, tensile strength of the obtained enamels was calculated with the help of the additive constants of Winkelmann & Schott and Mayer & Havas. A good adhesion of the vitreous enamels to the metal substrates of brass-coated steel and to the copper plates was found. After firing at 800 - 820oC for 5 min at maximum temperature the resulting enamels are transparent (compositions 2, 4, 5, 6, 7 and 8), semi-transparent (composition 4) and opaque white (composition 1). Coloured enamels in yellow (with 1 mass % Fe2O3), turquoise blue (with 1 mass % CuO) and dark brown (with 1 mass % NiO) have been obtained. The new developed enamels can be used for the decoration of metals and for jewelry.