What is the process flow of sand casting?

Sand casting production consists of fine sand in a mold, which is usually hollowed out in the middle, and the molten metal liquid is poured into the mold, waiting for the liquid to cool, remove the mold and complete the casting.

• What is the process flow of sand casting?

• What is the role of sand casting cleaning?

• What are the production characteristics of sand casting?

What is the process flow of sand casting?

Mapping

The traditional method is to obtain casting drawings and send them to the foundry. This process can be done in the quotation. Today, more and more customers and foundries are relying on computer aided design instead.

Mold

In sand casting, molds are made from wood or other metallic materials. In this process, we ask our engineers to make the mold size slightly larger than the finished product, the difference is called shrinkage allowance. The purpose of this is to ensure that the molten metal acts on the mold to solidify and shrink, preventing voids during casting.

Core making

Core making is simply done by placing resin grains in a mold to form a cast of the inner surface. The void between the core and the mold thus becomes the casting.

Formation

During the melting and molding process, the mold must be prepared. Molding generally includes supporting frame of the mold, pulling the mold to separate it during casting, melting the previously placed core in the mold, and closing the mouth of the mold.

What is the role of sand casting cleaning?

The purpose of sand casting is to remove grit, sand and excess metal from the casting. Welding, sand removal can improve the appearance of the casting surface.

The burnt sand and scale removed to improve the appearance of the surface of the casting. Excess metal and other risers are removed. Move one step closer to welding and grinding and other steps. Finally, check the defects and overall quality.

The choice of casting location in sand casting.

(1) The important machining surface of the casting should face downward or to the side.

(2) The wide plane of the casting should face downward.

(3) The thin-walled part with larger area should be placed in the lower part of the mold or in vertical inclined position.

(4) For castings prone to shrinkage, the thicker part should be placed at the top or side.

(5) The number of cores should be minimized and it is easy to place, fix and vent.

What are the production characteristics of sand casting?

1. permeability

When the metal solution is poured into the sand mold, the high temperature of the melt evaporates the water in the molding sand into gas. If the air permeability of the molding sand is good, these gases can easily escape and the casting can avoid the occurrence of defects such as pores.

2. Strength

When the molten metal flows into the sand mold, the sand mold will be heated and become dry, and the bond strength of the sand particles at this time must also be able to resist the slight erosion and pressure of gold metal.

3. refractoriness

Molding sand must retain its original physical and chemical properties at high temperatures and not deform or melt.

4. fineness

In order to obtain castings with better surface smoothness, the sand casting must have adequate fineness to prevent molten metal from penetrating between the casting sands and forming poor casting surfaces.

5. collapsibility

Collapsibility of the molding sand is good, which facilitates cleaning of the castings and recovery and reprocessing of the molding sand.

FHZL will continue its efforts to refine and innovate 3D printing technology to accelerate the transformation and modernization of traditional foundries.