Moulding sand for aluminum casting and preparation method of moulding sand

Abstract

The invention discloses moulding sand for aluminum casting. The moulding sand is prepared from, by weight, 240-260 parts of fresh sand, 50-60 parts of bentonite, 5-8 parts of xylogen, 1-2 parts of sodium benzoate, 9-12 parts of nanoscale ceramic powder, 3-6 parts of sodium alga acid, 1-2 parts of ethyl silicate, 70-80 parts of titanium dioxide, 3-5 parts of sodium hexametaphosphate, 2-3 parts of polyvinyl alcohol, 1-2 parts of tributyl phosphate and a proper amount of water. According to the moulding sand, the fresh sand and the bentonite are subjected to roasting, dispersed grinding and thenhigh-temperature roasting, and the moulding sand is smooth and has excellent air permeability, cohesiveness, toughness and plasticity; meanwhile, the nanoscale ceramic powder and the titanium dioxideare adopted, the degree of finish and smoothness are improved, the shrinkage rate of the moulding sand is low, the moulding sand is not prone to cracking, and high-temperature collapsibility is good;and the moulding sand is suitable for casting of an aluminum product, shrinkage holes, shrinkage porosity, peeling and under-peel slag holes are reduced, the surface is smooth, and the size is standard.

Description

technical field [0001] The invention relates to the field of casting, in particular to a molding sand used for casting aluminum 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 raw sa...

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.