An expandable aggregate mixture for a mold, which contains an aggregate, a water-soluble binder, a water-soluble foaming agent, water, and spherical metal oxide particles.

An expandable aggregate mixture for a mold, which contains an aggregate, a water-soluble binder, a water-soluble foaming agent, water, and spherical metal oxide particles.

A casting green sand mold comprising at least a pair of green sand mold parts each having a cavity portion, which are stacked with their cavity portions aligned to form a metal-melt-receiving cavity; each of the green sand mold parts being formed by casting sand containing a binder and water; a hardening-resin-based coating layer being formed on at least the cavity portion of each green sand mold part; the coating layer having gas-permeable pores having sufficient permeability to permit a gas generated by pouring a metal melt to escape; and a water content in a surface layer including the coating layer in a range from the cavity surface to the depth of 5 mm being smaller than that in the inner portion of the green sand mold.

Compositions useful for foundry processes such as green sandcasting are discussed. The compositions may include ball clay, bentonite, and a carbonaceous material. The ball clay may include leonardite and/or causticized lignite, e.g., as a portion of the natural ball clay deposit. The composition may further include sand, such that the resulting mixture may be formed into a green sand mold for use in casting molded articles. Incorporation of ball clay materials in the compositions may help to improve the quality of the casted article.

A composition which comprises a soluble or partially soluble phosphate, a refractory material and less than 1% of an oxide or hydroxide of magnesium or calcium. The composition may be mixed with water to form an investment casting slurry into which a wax pattern may be dipped. Slurry coated onto the pattern may be set by applying a stucco composition which comprises an oxide or hydroxide of magnesium or calcium. Coats of set slurry may be built up on the pattern to form an investment casting shell.

A structure for manufacturing a cast article includes an organic component, at least a portion thereof being an organic fiber. The structure has a mass reduction rate of 1 mass % or greater to less than 20 mass % when heated under nitrogen atmosphere at 1000 C. for 30 minutes. The cast-article-manufacturing structure includes an inorganic particle. The cast-article-manufacturing structure includes, as the inorganic particle, a first inorganic particle having a predetermined shape and/or physical property, and a second inorganic particle having a predetermined shape and/or physical property different from the first inorganic particle. In addition thereto or instead thereof, the cast-article-manufacturing structure has a maximum bending stress of 9 MPa or greater measured in conformity with JIS K7017, and a bending strain of 0.6% or greater at the maximum bending stress.

A method of forming a dry molding sand additive may include recovering a non-sand fraction from a foundry waste material and adding the non-sand fraction to a dry molding sand additive formulation to form a dry molding sand additive. Adding the non-sand fraction to the dry molding sand additive formulation may reduce the amount of fresh clay and carbon to produce the dry molding sand additive. A method of forming a molding sand additive may include recovering a waste molding sand additive composition having a clay or carbon content differing from a desired clay and carbon content, recycling the waste molding sand additive as a raw material in production of a fresh molding sand additive, and adjusting the amount of fresh clay or carbon added during production of the fresh molding sand additive to achieve the desired clay and carbon content.

The present invention relates to a casting core for casting moulds, 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. The present invention also relates to a method for producing the casting core according to the invention and to the use of the casting core according to the invention.

Compositions useful for green sandcasting are discussed, as well as methods of preparing and using such compositions. Binder compositions may comprise a carbonaceous material, an inorganic binding agent, and a high aspect ratio silicate, wherein at least one of the carbonaceous material or the inorganic material in the binder composition may be oxidized. For example, the inorganic binding agent may be oxidized with a ratio of ferrous iron (Fe.sup.2+) to ferric iron (Fe.sup.3+) less than 1.2. or less than 1. Green sand prepared from such binder compositions may exhibit a reduction in emissions during sandcasting.

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.