Ceramic core and method for producing same
AssigneeHitachi Metals, Ltd.
InventorHideko Fukushima
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Abstract
A ceramic core is obtained by firing a mixture that contains 0.1-15.0% by mass of alumina and 0.005-0.1% by mass of potassium and/or sodium with the balance made up of silica and unavoidable impurities. Not less than 90% by mass of amorphous silica is contained in 100% by mass of the silica. A method for producing a ceramic core, wherein: a blended material is obtained by blending 25-45% by volume of a binder into 55-75% by volume of a mixture that is obtained by mixing alumina, potassium and/or sodium, and silica so as to have the above-mentioned composition; the blended material is injected into a die so as to obtain a molded body; and the molded body is degreased at 500-600° C. for 1-10 hours, and then fired at 1,200-1,400° C. for 1-10 hours.
Claims6
A sintered ceramic core comprising 0.1 to 15.0 mass % of alumina, 0.005 to 0.1 mass % of at least one of potassium and sodium, optionally 0.5 to 35.0 mass % of zircon, and the balance being silica and inevitable impurities, wherein the silica comprises not less than 90 mass % amorphous silica.
Dependencies are inferred from the claim text.