Abstract: A method of casting an article from a molten metal including: admitting molten metal to a mould formed from a foundry sand comprising a blend of silica sand and a zircon aggregate, the zircon aggregate exhibiting a sharp rise in linear thermal expansion coefficient in a temperature band above 1200° C. and up to 1600° C.; and cooling the mould and molten metal to solidify the molten metal and form a cast article, wherein one or more surfaces of the mould, or of a portion of the mould, in contact with the molten metal are uncoated.

Abstract: A method of casting an article from a molten metal including: admitting molten metal to a mould formed from a foundry sand comprising a blend of silica sand and a zircon aggregate, the zircon aggregate exhibiting a sharp rise in linear thermal expansion coefficient in a temperature band above 1200° C. and up to 1600° C.; and cooling the mould and molten metal to solidify the molten metal and form a cast article, wherein one or more surfaces of the mould, or of a portion of the mould, in contact with the molten metal are uncoated.

Abstract: A foundry sand comprises a blend that includes a silica sand and a zircon aggregate. The zircon aggregate exhibiting a sharp rise in linear thermal expansion coefficient in a temperature band above 1200° C. A method of casting an article in molten metal at a temperature above 1200° C. includes forming a single or multi-part mold for the article from the above-described foundry sand, admitting molten metal to the mold at a temperature such that at least one or more regions of the foundry sand in contact with the admitted metal are heated to a temperature within the temperature band, and cooling the mold and metal to obtain a cast article.

Abstract: A foundry sand comprises a blend that includes a silica sand and a zircon aggregate. The zircon aggregate exhibiting a sharp rise in linear thermal expansion coefficient in a temperature band above 1200° C. A method of casting an article in molten metal at a temperature above 1200° C. includes forming a single or multi-part mould for the article from the above-described foundry sand, admitting molten metal to the mould at a temperature such that at least one or more regions of the foundry sand in contact with the admitted metal are heated to a temperature within the temperature band, and cooling the mould and metal to obtain a cast article.