Carbon–silica alloy material as silicon carbide precursor prepared from phenol resin and ethyl silicate

Abstract

Three kinds of inorganic–organic hybrid gel sheets were prepared from the liquid mixtures of ethyl silicate and water–soluble phenol resin. The prepared transparent gel sheets were fired at various temperatures. The density of the fired sheets jumped up at 773–1023 K with disappearance of organic groups. The sheets kept the prepared shape after the 1273 K firing, and their density increased with the silica content. After the firing at 1873 K, the sheets with high carbon content (C/SiO2: 5.60, 3.52) were converted into the sheets composed of silicon carbide aggregate with excess carbon, while the sheet with low carbon content (C/SiO2: 1.43) was converted into the fragile powders.