Sand casting is a common casting process

Sand casting is a common casting process, also known as sand casting. It is a method of making castings by using sand in a casting mold.

The sand casting process includes the following steps:

1. Mold preparation: Make two molds with positive and negative concavities according to the shape and size of the part. The positive mold is called the core, and the negative mold is called the sandbox. These molds are usually made of refractory materials.

2. Sand mold preparation: Place the core in the sand box and fill it with foundry sand around the core. Foundry sand is usually a special blend of fine sand, clay and water. After filling is completed, the sand mold is compacted using pressure or vibration.

3. Melting metal: Melting the desired metal into a liquid state, usually using a furnace to heat the metal material. Once the metal reaches the appropriate melting point, the next step can begin.

4. Pouring: Liquid metal is slowly poured into a sand mold, filling the entire shape. The pouring process requires controlled temperature and speed to avoid bubbles, shrinkage cavities or other defects.

5. Solidification and Cooling: Once the liquid metal in the casting has cooled and solidified, the mold can be opened and the solidified casting removed from the sand mold.

6. Cleaning and post-processing: The removed castings may have some sand or grit attached to the surface and need to be cleaned and trimmed. Mechanical or chemical methods can be used to remove grit and perform necessary trimming and treatment.

Sand casting is a flexible and economical casting method suitable for producing metal parts of various sizes and shapes. It is widely used in industries such as automotive, machinery, aerospace and energy.

The sand casting process can be summarized simply as the following steps: mold preparation, sand preparation, melting metal, pouring, solidification and cooling, cleaning and post-processing.

Sand casting can be classified into the following types according to different sand molds:

1. Mixed Sand Casting: This is the most common type of sand casting. In mixed sand casting, a composite sand containing sand, binder and water is used. This sand mold has high strength and durability and is suitable for producing small, medium and large castings.

2. Binder sand casting: This type of sand casting uses a sand mold with a special binder. Binders enhance the strength and durability of sand molds while also improving the surface quality and accuracy of castings.

3. Hard sand casting: Hard sand casting uses a hard sand mold with high fire resistance and durability. This sand mold is suitable for producing large and high-load castings, such as engine blocks and bases.

4. Sand casting by demoulding method: In this type of sand casting, different demoulding methods are used to make the preparation and mold taking of the sand mold more convenient. Common release methods include green sand casting, dry sand casting and release agent sand casting.

5. Moving model sand casting: Moving model sand casting is a sand casting method that uses a moving mold. This method is suitable for producing castings with complex shapes and internal cavity structures, such as gears and turbines.

The above is the general process and common classification of sand casting. The specific process and classification may change according to different casting requirements and materials.