Molding sand used for special casting mould surface and preparation method thereof

Abstract

The invention discloses molding sand used for a special casting mould surface. The molding sand is prepared from the following raw materials in parts by weight: 300-330 parts of zircon sand, 55-65 parts of fused magnesite, 12-18 parts of aluminum-magnesium spinel, 20-25 parts of kyanite, 3-5 parts of tributyl citrate, 3-4 parts of copper oxide, 10-15 parts of wood fibers, 2-4 parts of carboxymethyl cellulose, 12-20 parts of graphite powder, 6-9 parts of sodium metasilicate and an appropriate amount of water. According to the molding sand disclosed by the invention, the zircon sand is selected as a main molding material aiming at the characteristics of high casting strength requirements and good fire resistance degree; the quality of the casting mould surface can be obviously improved by the added fused magnesite, aluminum-magnesium spinel and kyanite through processes of roasting, grinding, dispersing and the like; meanwhile, the carboxymethyl cellulose, the graphite powder and the sodium metasilicate are added, so that mobility of the molding sand is increased, mould charging capacity is improved, fire resistance performance is ensured, and molding sand fineness is strengthened. Besides, the molding sand disclosed by the invention is suitable for casting a product with a fine process, high in yield and precise in dimension.

Description

technical field [0001] The invention relates to the casting field, in particular to a molding sand used for a special casting surface and a preparation method thereof. Background technique [0002] Molding sand is a material used for molding in casting. Molding sand is generally made by mixing molding materials such as raw sand for casting, molding sand binder and auxiliary additives in a certain proportion. Natural silica sand containing clay can also be used. In the usual molding sand formula for aluminum casting, the particle size of the molding sand is too large or If it is too small, the diameter of the molding sand is too large. Although the air permeability is good, the surface of the aluminum sand parts is rough and the finish is not good. If the diameter of the molding sand is too small, the air permeability of the sand mold is not good, and the aluminum castings have pores. Coal powder clay green sand, which is widely used at home and abroad, is generally made of ...

AI Technical Summary

Problems solved by technology

Molding sand is generally made by mixing molding materials such as raw sand for casting, molding sand binder and auxiliary additives in a certain proportion. Natural silica sand containing clay can also be used. In the usual molding sand formula for aluminum casting, the particle size of the molding sand is too large or If it is too small, the diameter of the sand material is too large. Although the air permeability is good, the surface of the aluminum sand parts is rough and the finish is not good. The diameter of the sand material is too small, resulting in poor air permeability of the sand mold and air holes in the aluminum casting

Coal powder clay green sand, which is widely used at home and abroad, is generally made of raw sand, binders, coal powder additives, etc. and water. It has a certain anti-sticking sand effect, low material cost, and high production efficiency. However, its consumption is large, the emission is serious, and the coal powder is burned and decomposed in the casting process to produce toxic gas pollution.