China Sand Casting Foundry

Sand casting is to pour molten metal into a mold made of sand and a binder, and use the plasticity and good air permeability of the sand mold to form a casting. Sand casting is highly flexible and can cast castings with complex shapes and large sizes, with a relatively short production cycle.

The basic raw materials for sand casting are river sand, silica sand or fine sand. Sand needs to be mixed with binders (such as bentonite, resin, clay, etc.) and additives (such as water, oil or other chemical additives).

(The two common sand molds are resin sand casting and clay sand casting)

Fill the mixed sand into the mold to form a sand mold.

The core is used for the internal space of the sand casting. It is generally made by mixing fine sand and binder and pressing. For castings with complex structures, cores are needed to form internal cavities or complex structures.

The upper and lower mold boxes of the sand mold are closed to form a complete casting.

The core is installed in the appropriate position before mold closing to ensure that the core does not shift during the pouring process, affecting the quality of the sand casting.

The required metal material is melted at high temperature and enters the sand mold through the gate and riser. The molten metal flows into the mold cavity under the action of gravity, filling the entire space of the sand mold to form the initial shape of the sand casting.

After the molten metal enters the sand mold, it begins to gradually cool and solidify into a solid state. The time required for the casting to cool and solidify in the sand mold is related to the size, shape and properties of the metal material.

After the casting is completely cooled and solidified, disassemble the sand mold and take out the sand casting.

Remove sand particles, risers, gates, cores and other attachments on the surface of the casting.

The cleaned castings usually need to be inspected for quality, such as size inspection, surface inspection, mechanical property testing, etc.

Heat treatment: Heat treatment (such as annealing, normalizing, quenching, etc.) is performed to improve the mechanical properties of sand castings and eliminate internal stress.

Processing: According to the needs of the casting, post-processing such as drilling, tapping, machining, etc. is carried out to achieve the final precision requirements.