| 摘要 |
FN: 43922CANlA A moldable composition comprising a mixture of magnesia, alumina, and silicon carbide powders or agglomerates thereof, the powders having an overall average size of at most 5.0 micrometers, preferably an average size in the range of 0.2 to 2.0 micrometers, optionally a polymeric binder, optionally a fluxing agent, and optionally a plasticizer or lubricant which exhibits little or no controlled dimensional stability upon being fired to a cordierite ceramic material in a novel process. The process involves incorporation of silicon carbide powder into the moldable composition and the reaction of this silicon carbide upon firing to produce silicon dioxide. The cordierite ceramic material is useful where the dimensions of a shaped or molded part must be preserved after firing, as, for example, in the preparation of dental articles or as a mold for casting metals. |
