What is sand casting, casting steps and sand casting purpose?

What is sand casting?

The process of sand casting is a manufacturing process in which liquid metal is poured into a sand mold that contains a hollow cavity containing the desired shape and is allowed to solidify after it has been poured into the mold.

During casting, a liquid material is usually poured into a mold, which contains a hollow cavity that is shaped as desired, and then solidified. A variety of casting materials are available, including metal, concrete, epoxy, plaster, and clay. In this article, sand casting will be discussed.

What are the steps involved in sand casting?

Molding with sand includes several steps. The sand casting process begins with the creation of a mold pattern and the gate system. Each pattern requires a mold customized to the exact size and shape of the part to be cast. Additionally, the setup requires a two-part casting flask, known as a cope and drag flask.

After placing the mold pattern in sand, a series of tunnels and a pouring cup are used to set up a gate system. Once the pattern has been covered with sand, it is removed from the mold cavity. When the metal is heated to a high temperature, it becomes liquid. The temperature at which it melts depends on the alloy. Some metals take longer to melt.

Once the molten metal is poured into the mold, it begins to cool and solidify. The sand mold needs to be separated along a parting line to remove the part. The mold cavities are destroyed during this process, but the mold pattern is usually reused.

What is the purpose of sand casting?

Using sand casting, metal parts can be made in any size – from small to large. With its dimensional accuracy and low cost, sand casting is an excellent solution for a wide range of products and assemblies. In addition, sand moulding is capable of producing castings with excellent exteriors and inner cores. It is possible to cast almost anything that is metal. Taking moist sand mixed with molten metal and cooling it can create hollows.

The following products are typically manufactured using sand casting service:

  • Engine blocks
  • Axles
  • Gearboxes
  • Exhaust manifolds
  • Pistons
  • Impellers 
  • Turbine housings
  • Pumps

What type of sand is used for sand casting?

Resin sand

When resin sand is heated and mixed, it becomes a solid mold with a smooth surface. Solid molds mean fewer defective castings, but they are more costly and take longer to produce. It takes longer to make resin sand molds than it does to make green sand molds since each must be mixed and burned to make the perfect mold. Resin sand is more expensive, and even though it can be reused, it has to be replenished constantly, which results in a more expensive process.

Sodium silicate or water glass

By passing carbon dioxide through sodium silicate, it can quickly go from a liquid to a solid. This results in sodium silicate dehydrating. When a cavity is required within a casting, this process is very useful. It is possible to use sodium silicate to create a solid core for castings, but it must be mixed with other materials to facilitate the breakdown of the core after casting. When the mixture is incorrect, the core will become lodged within the casting, making it useless.

Green sand

This type of sand mold is made from wet sand and is sometimes referred to as clay. The mold is still in an uncured state when the metal is poured. Sand casting with green sand is fast and inexpensive, since it can be reused. However, the downside is that the sand is a soft mold and can collapse or shift during casting, leaving an unusable cast. It has, however, been in use for centuries and is still used today, despite its shortcomings.

Interesting Related Article: ” 5 Crucial SEO Components for Manufacturing Companies