Disclosed herein is a casting core for casting molds, the casting core comprising an inner core and an outer core arranged around the inner core. The outer core contains or consists of ceramic particles bound with a binder. The inner core contains ceramic particles bound with a binder and additionally one or more placeholder elements. The placeholder element(s) is/are at least partially thermally decomposable. Also disclosed is a method for producing the casting core and use of the casting core.

A structure for manufacturing castings, containing an inorganic fiber, a layered clay mineral, and an inorganic particle other than the layered clay mineral and having an organic content of 5 mass % or lower or having a mass loss of 5 mass % or lower when heated at 1000° C. for 30 minutes. The inorganic particle preferably contains one or more selected from obsidian, graphite, and mullite. The inorganic fiber preferably contains carbon fiber. The inorganic fiber preferably has an average length of 0.5 to 15 mm. The layered clay mineral preferably contains one or more selected from bentonite and montmorillonite.

What are described are the use of a refractory coating composition for production of cores for diecasting, a kit for production of cores for use in diecasting, a method of producing cores for use in diecasting, cores for use in diecasting, and the use of such cores in diecasting, especially of lightweight metals

The additive composition of the present invention is one blended in a sand composition which is subjected to foaming to mold a sand mold, and includes (A) an alkylsulfonate metal salt having an alkyl group with 9 to 22 carbon atoms. The additive composition may further include at least one component selected from a group consisting of (B) an alkylsulfate metal salt, (C) a polyoxyalkylene alkyl ether sulfate metal salt, and (D) an alkylbenzene sulfonate metal salt.

The invention relates to a binder, which contains water glass and further a phosphate or a borate or both. The invention further relates to a method for constructing molds and cores layer by layer, the molds and cores comprising a construction material mixture, which at least comprises a refractory molding base material, and the binder. In order to produce the molds and cores layer by layer in 3-D printing, the refractory molding base material is applied layer by layer and is selectively printed with the binder layer by layer, and consequently a body corresponding to the molds or cores is constructed and the molds or cores are released after the unbonded construction material mixture has been removed.

A description is given of the use of an additive mixture (A) for combination with a solution or dispersion (B) comprising waterglass, for producing a moulding material mixture for producing articles from the group consisting of foundry moulds and foundry cores; a multi-component binder system comprising (A) an additive mixture and (B) a solution or dispersion comprising waterglass; a moulding material mixture comprising a mould base material (C) and also components (A) and (B) of such a multi-component binder system; a method for producing an article from the group consisting of foundry moulds and foundry cores; articles from the group consisting of foundry moulds and foundry cores; and the use of such an article for metal casting, preferably for light metal casting, more particularly for aluminium casting.

Sized molds for metal casting are obtained from molding material mixtures on the basis of inorganic bonding agents containing at least one phosphatic compound and at least one oxidic boron compound, especially sized, water glass-bound forms and cores, having at least one refractory base molding material, water glass as inorganic bonding agent and amorphous particulate silicon dioxide and one or more powdery oxidic boron compounds and one or more phosphatic compounds. The invention furthermore relates to a method for producing sized foundry mold bodies and use thereof, in particular for producing cast parts from iron alloys. The sizing is a water-based sizing.

Foundry casting elements and methods of forming the same, the methods including: forming an aqueous slurry including an inorganic binder precursor, shaping the slurry using a pattern, curing the shaped slurry using a low temperature solidification process to form a casting element, and removing the pattern from the casting element.

A method for manufacturing a structure from a granular material, called sand, in particular a mold. A layer of sand is deposited. The layer of sand is selectively agglomerated by spraying, using a spray nozzle, an inorganic binder having an M2SiO3 type (meta)silicate dissolved in a solvent. Prior to the spraying, the inorganic binder is heated to a temperature to confer on it a viscosity less than 0.2 Pa.Math.s. A device for implementing the method is provided.

The present invention describes a coating composition for the foundry industry, for use in the foundry, in particular comprising certain organic ester compounds of a formula (I) and particulate, amorphous silicon dioxide (SiO.sub.2); and also coated foundry molding elements, especially foundry molds and/or foundry cores, which each comprise a coating composition of the invention. The invention further describes the use of a coating composition of the invention for producing a coating on a foundry molding element and a method for producing a foundry molding element coated with a water-containing refractory coating. The invention likewise describes a kit whose contents include a coating composition of the invention.