Good plasticity mold core molding sand and preparation method thereof

Abstract

The invention relates to good plasticity mold core molding sand, which is prepared from the following raw materials by weight: 20-30 parts of chromite sand, 10-14 parts of bauxite, 15-20 parts of brown corundum powder, 6-8 parts of alpha-Al2O3 micro-powder, 2-3 parts of sodium tripolyphosphate, 1-2 parts of dimethyl silicon oil, 4-5 parts of a furan resin, 14-18 parts of poly carbosilane powder, 220-240 parts of clay, 2-3 parts of fatty acid sodium, 4-5 parts of potassium methyl silicate, a proper amount of water, and 20-30 parts of an auxiliary agent. According to the good plasticity mold core molding sand, the clay is used, such that the matching cost is low, the chilling effect is good, and the gas permeability is good; the alpha-Al2O3 micro-powder is added, such that the plasticity is good, the thermal conductivity is good, the molding sand is suitable for mold core manufacturing, and the cast hole shrinkage and dispersed shrinkage solving effect can achieve more than 90, and the cast yield can be increased; the auxiliary agent of the present invention adopts alumina and other high temperature resistance materials, such that the auxiliary agent can not melt during casting, the adhesion of the clay particles can be prevented, and the recycling is easily performed; and the clay is wrapped on the surface, and the binding force with the clay particles is strong.

Description

technical field [0001] The invention relates to the field of casting, in particular to a core molding sand with good plasticity and a preparation method thereof. Background technique [0002] At present, molding sand is generally formed by mixing molding materials such as raw sand for casting, molding sand binder and auxiliary additives in a certain proportion. If the particle size of the molding sand is too large, although the air permeability is good, the surface of the casting is relatively rough and the finish is not good; if the particle size of the molding sand is too small, the air permeability of the sand mold is not good, and the aluminum casting has pores. Therefore, it is necessary to control the particle size of the molding sand. [0003] Natural clay-containing silica sand can also be used for molding sand. Coal powder clay green sand widely used at home and abroad is generally made of raw sand, binder, coal powder additives, etc. mixed with water, which has a ...

AI Technical Summary

Problems solved by technology

[0003] Natural clay-containing silica sand can also be used for molding sand. Coal powder clay green sand widely used at home and abroad is generally made of raw sand, binder, coal powder additives, etc. mixed with water, which has a certain anti-sticking sand effect and material The advantages of low cost and high production efficiency, but its consumption is large, the emission is serious, and the combustion and decomposition of pulverized coal in the casting process will produce toxic gas pollution

Traditional clay molding sand is not easy to recycle, and there are still some shortcomings such as easy sand bean, poor collapsibility, poor fluidity, and poor heat resistance, which need to be improved