Casting Function and Air Permeability of Aluminum Castings

The advantage of aluminum casting is that it has been widely used in the automobile industry since its lightweight quantification. The density of aluminum casting is smaller than that of cast iron and cast steel, but its specific strength is higher. Therefore, aluminum alloy castings can reduce the weight of the layout under the same loading condition. Therefore, aluminum alloy castings are widely used in aviation industry, power machinery and transportation machinery production.

Aluminum casting has outstanding casting function in the process of operation, mainly because of the low melting point of its products, so it can be widely used in casting methods such as metal mold and pressure casting. In this way, it can improve the connotation quality, scale precision, surface smoothness and production power of the aluminum die casting.

Due to the high latent heat of solidification, the solidification process of aluminum casting liquid is much longer than that of cast steel and cast iron continuously at the same time under the condition of the same component.

When the high temperature metal liquid in the aluminum alloy die casting is poured into the casting mold, the product will be filled with a large amount of gas. The gas must be discharged directly from the casting mold. Otherwise, it will lead to defects such as porosity and insufficient casting. The permeability of the mold is affected by the size of sand, the content of clay, the content of water and the compactness of sand.

The strength of the molding sand of aluminum casting is called strength. The molding sand must be strong enough to avoid collapse during molding, handling and case closing, and the casting surface will not be damaged during pouring. The strength of molding sand should not be too high; otherwise, it will cause the decrease of air permeability and concession, which will lead to defects in the aluminum die casting.