Behavior of copper oxide in silicoborate glazed glasses

Copper-containing glazed glasses in the B[2]O[5] - SiO[2] – Al[2]O[3] – CaO – CuO system with a copper oxide molar content of 5 to 25%, added during synthesis of the glasses, was investigated. The glasses with a minimum content of 15% B2O and 15 – 25% CuO crystallized during processing with separation of fine-needle CuO crystals. However, all glasses formed a good glaze coating when applied on ceramics at temperatures of 900 – 1000°C. The CuO crystals totally dissolved in the melt