Showing papers by "Sumio Sakka published in 1983"

Preparation and properties of CaAlSiON oxynitride glasses

Abstract: The effect of preparation condition on the melting behavior and the effect of nitrogen content on the properties were investigated for CaAlSiON OXYNITRIDE GLASSES. It was found that melting at lower temperatures produces more homogeneous and clearer glasses than melting at higher temperatures when the glass is melted at temperatures between 1530°C and 1750°C. The density, glass transition and softening temperatures, Vickers hardness and Young's modulus increased markedly with increasing nitrogen content. The observed values of densities of nitrogen-containing glasses was found to agree well with the additivity calculation based on the assumption that each nitrogen atom in the glass structure is connected with three silicon atoms.

Preparation of Glasses and Ceramics for Electrical Use based on Alkoxide and Unidirectional Solidification Methods

Abstract: A review has been made on two methods of preparing glasses and ceramics: (1) alkoxide method for preparing oxide coating films and (2) unidirectional solidification of melts for preparing oriented oxide crystalline bodies. In the alkoxide method for coating, the substrate is dipped in the metal alkoxide solution, withdrawn and heated to several hundred degrees Celsius. Formation of SiO2 and BaTiO3 films has been described in detail. In the unidirectional solidification the melt is cooled down in the presence of temperature gradient. Formation of unidirectional crystalline bodies of 0.7NaNbO30.3BaTiO3, γ-6Bi2O3SiO2, PbTiO3 and Bi2PbNb2O9 has been introduced in detail.

Thermal Expansion of Substituted Copper Aluminosilicate Glasses

Abstract: The effects of various components on the thermal expansion coefficient of low-expansion Cu2O-Al2O3-SiO2 glasses were examined. When a component of glass was substituted by another oxide, the expansion coefficient always increased, except for substitution of Al2O3 by B2O3. This result indicates that the essential components to maintain the low expansivity are Cu2O, such trivalent oxides as Al2O3 and B2O3, and tetravalent oxide SiO2. Glasses of the systems Cu2O-Al2O3-B2O3, Cu2O-Al2O3-GeO2, and Cu2O-Al2O3-P2O5, which were derived by replacing SiO2 by other network-forming oxides, showed fairly low expansion coefficients compared with other conventional borate, germanate, and phosphate glasses. It was also found that the valence state of copper ions is important for the thermal expansion characteristics of these glasses; Cu+ ions contribute to the low expansion coefficient.

Thermal expansion of substituted copper aluminosilicate glasses

Abstract: The effects of various components on the thermal expansion coefficient of low-expansion Cu2O-Al2O3-SiO2 glasses were examined. When a component of glass was substituted by another oxide, the expansion coefficient always increased, except for substitution of Al2O3 by B2O3. This result indicates that the essential components to maintain the low expansivity are Cu2O, such trivalent oxides as Al2O3 and B2O3, and tetravalent oxide SiO2. Glasses of the systems Cu2O-Al2O3-B2O3, Cu2O-Al2O3-GeO2, and Cu2O-Al2O3-P2O5, which were derived by replacing SiO2 by other network-forming oxides, showed fairly low expansion coefficients compared with other conventional borate, germanate, and phosphate glasses. It was also found that the valence state of copper ions is important for the thermal expansion characteristics of these glasses; Cu+ ions contribute to the low expansion coefficient.