Advantages of vacuum casting process

Vacuum casting is also called negative pressure seal casting, reduced pressure casting or V-method casting. Vacuum pressure casting requires the use of air extraction equipment to extract the air inside the casting mold, and then uses the pressure difference between the inside and outside of the mold to cover the model and template with the heated plastic film. The mold will become strong enough to withstand the molten metal during the casting process. After obtaining the vacuum mold, fill the sand box with dry sand without binder, then seal the top surface of the sand mold with plastic film, and then vacuum to make the sand solid and tight. Afterwards, the vacuum foundry takes out the mold, puts in the sand core, closes the mold, and prepares it for pouring. Finally, the molten metal cools and solidifies to obtain the casting.

Advantages of vacuum casting process

1) Vacuum castings have high dimensional accuracy, clear outlines and smooth surfaces.

The surface roughness of V process castings can reach Ra=25~2.5μm. The dimensional tolerance level of castings can reach CT5~CT7. Negative pressure castings have good appearance quality and reliable internal quality.

2) Vacuum castings can be used in a wide range of industries. It can be used for both single-piece small batch production and large-scale production. Especially large and medium-sized castings and thin-walled castings are more suitable for vacuum casting.

3) The molding sand does not contain binders, water and additives, making molding sand processing simple.

4) Vacuum castings are easy to clean. Less harmful gases are produced during the casting process.

5) The hardness of the sand mold is high and uniform, and the mold cavity is not easily deformed.

Since the surface of the model is covered with plastic film, there is no need to vibrate or knock when drawing the mold. The air suction and negative pressure make the molding sand dense, and the sand hardness is high and uniform. Under the heat of molten metal, the mold cavity is not easily deformed. Moreover, the existence of negative pressure is conducive to fully filling the model with molten metal.