The present invention intends to provide a gypsum-based embedding material composition for casting, the composition being useful as a rapid-heating type gypsum-based embedding material making it possible to provide a product with which leaving time is made short, which has never been realized in conventional products, and also intends to provide a method for producing the same. A gypsum-based embedding material composition for casting, the composition being a gypsum-based powdery embedding material composition for casting to be used for a rapid-heating type embedding material, the gypsum-based powdery embedding material composition being such that a set product is put into a high-temperature furnace, the set product obtained by adding a malaxation liquid into the composition to perform malaxation and then setting a resultant mixture, wherein the gypsum-based embedding material composition for casting contains as main components calcined gypsum, quartz, and cristobalite, and contains at least one co-pulverized material selected from a co-pulverized material of calcined gypsum and quartz, a co-pulverized material of calcined gypsum and cristobalite, or a co-pulverized material of calcined gypsum, quartz, and cristobalite, and a powdery moisture-retaining component or a liquid moisture-retaining component having a low water content, the composition having an average particle diameter of 30 m or less, and a method for producing the same.

The present invention intends to provide a gypsum-based embedding material composition for casting, the composition being useful as a rapid-heating type gypsum-based embedding material making it possible to provide a product with which leaving time is made short, which has never been realized in conventional products, and also intends to provide a method for producing the same. A gypsum-based embedding material composition for casting, the composition being a gypsum-based powdery embedding material composition for casting to be used for a rapid-heating type embedding material, the gypsum-based powdery embedding material composition being such that a set product is put into a high-temperature furnace, the set product obtained by adding a malaxation liquid into the composition to perform malaxation and then setting a resultant mixture, wherein the gypsum-based embedding material composition for casting contains as main components calcined gypsum, quartz, and cristobalite, and contains at least one co-pulverized material selected from a co-pulverized material of calcined gypsum and quartz, a co-pulverized material of calcined gypsum and cristobalite, or a co-pulverized material of calcined gypsum, quartz, and cristobalite, and a powdery moisture-retaining component or a liquid moisture-retaining component having a low water content, the composition having an average particle diameter of 30 m or less, and a method for producing the same.

A slurry composition includes, by volume, a ceramic composition in an amount of from about 60 to about 75 percent and a binder in an amount of from about 25 to about 40 percent, plus a platinum group metal catalyst and a dopant. The ceramic composition includes, by volume of the ceramic composition, fine fused silica particles having a particle size d.sub.50 of from about 4 m to about 7 m, in an amount of from about 7 to about 40 percent; coarse fused silica particles having a d.sub.50 of from about 25 m to about 33 m, in an amount of from about 29 to about 60 percent; inert filler particles having a d.sub.50 of from about 5 m to about 25 m, in an amount of from about 8 to about 40 percent; and fumed silica particles, in an amount of up to about 15 percent.

A slurry composition includes, by volume, a ceramic composition in an amount of from about 60 to about 75 percent and a binder in an amount of from about 25 to about 40 percent, plus a platinum group metal catalyst and a dopant. The ceramic composition includes, by volume of the ceramic composition, fine fused silica particles having a particle size d.sub.50 of from about 4 m to about 7 m, in an amount of from about 7 to about 40 percent; coarse fused silica particles having a d.sub.50 of from about 25 m to about 33 m, in an amount of from about 29 to about 60 percent; inert filler particles having a d.sub.50 of from about 5 m to about 25 m, in an amount of from about 8 to about 40 percent; and fumed silica particles, in an amount of up to about 15 percent.

Provided herein are a saltcore for casting with aluminum and a manufacturing method thereof, and more particularly, a saltcore and a manufacturing method thereof capable of reducing shrinkage while satisfying strength during die-casting by including at least one cation of K.sup.+, Na.sup.+ and Mg.sup.2+ and at least one anion of Cl.sup. and CO.sub.3.sup.2, wherein a saltcore for casting with aluminum may include at least one cation of K.sup.+, Na.sup.+ and Mg.sup.2+ and at least one anion of Cl.sup. and CO.sub.3.sup.2.

Provided herein are a saltcore for casting with aluminum and a manufacturing method thereof, and more particularly, a saltcore and a manufacturing method thereof capable of reducing shrinkage while satisfying strength during die-casting by including at least one cation of K.sup.+, Na.sup.+ and Mg.sup.2+ and at least one anion of Cl.sup. and CO.sub.3.sup.2, wherein a saltcore for casting with aluminum may include at least one cation of K.sup.+, Na.sup.+ and Mg.sup.2+ and at least one anion of Cl.sup. and CO.sub.3.sup.2.

The invention concerns a method of manufacturing a shell mould (1) with several layers (2, 3, 4, 5), including at least one contact layer (2), from a model (6) of wax or other similar material of a part to be manufactured, the method comprising a step of dipping the model (6) into a contact slip forming the contact layer (2) and comprising an inorganic or organic binder and a powder, wherein the powder is a mullite-zirconia composite.

The invention concerns a method of manufacturing a shell mould (1) with several layers (2, 3, 4, 5), including at least one contact layer (2), from a model (6) of wax or other similar material of a part to be manufactured, the method comprising a step of dipping the model (6) into a contact slip forming the contact layer (2) and comprising an inorganic or organic binder and a powder, wherein the powder is a mullite-zirconia composite.

A slurry composition includes, by volume, a ceramic composition in an amount of from about 60 to about 75 percent and a binder in an amount of from about 25 to about 40 percent, plus a platinum group metal catalyst and a dopant. The ceramic composition includes, by volume of the ceramic composition, fine fused silica particles having a particle size d.sub.50 of from about 4 m to about 7 m, in an amount of from about 7 to about 40 percent; coarse fused silica particles having a d.sub.50 of from about 25 m to about 33 m, in an amount of from about 29 to about 60 percent; inert filler particles having a d.sub.50 of from about 5 m to about 25 m, in an amount of from about 8 to about 40 percent; and fumed silica particles, in an amount of up to about 15 percent.

A slurry composition includes, by volume, a ceramic composition in an amount of from about 60 to about 75 percent and a binder in an amount of from about 25 to about 40 percent, plus a platinum group metal catalyst and a dopant. The ceramic composition includes, by volume of the ceramic composition, fine fused silica particles having a particle size d.sub.50 of from about 4 m to about 7 m, in an amount of from about 7 to about 40 percent; coarse fused silica particles having a d.sub.50 of from about 25 m to about 33 m, in an amount of from about 29 to about 60 percent; inert filler particles having a d.sub.50 of from about 5 m to about 25 m, in an amount of from about 8 to about 40 percent; and fumed silica particles, in an amount of up to about 15 percent.