| 摘要 |
PURPOSE:To provide a durable non-metallic casting mold which is highly strong, is repeatedly usable and yields a good casting by impregnating silicon carbide to the surface layer of a mold formed of carbon. CONSTITUTION:This durable casting mold 1 is formed of carbon and the impregnated layer 2 of silicon carbide is formed to the surface part of the mold which contacts with a molten metal. The mold 1 is formed by molding, for example, pulverous carbon powder (may be graphite powder) under pressure to a prescribed shape, subjecting the molding to packed calcination at about 2,500 deg.C and impregnating SiC to such molding. The impregnation of SiC which acts as an antioxidant is executed by enveloping the carbon mold subjected to the above-mentioned molding and calcination with about 3-4mu pulverous SiC powder and heating the same to a high temp. The thickness of the layer 2 is preferably >=3mm and the content. of SiC in the layer 2 is about 5-20% but is not limited thereto. |
