There are two main categories: sand casting and special casting.
1 Ordinary sand casting uses sand as the mold material, also known as sand casting and sand casting, including 3 types of green sand, dry sand and chemically hardened sand, but not all sand can be used for casting. The advantage is that the cost is lower, because the sand used in the mold can be reused; the disadvantage is that the production of the mold is time-consuming, the mold itself cannot be reused, and the finished product can only be obtained after being destroyed.
1.1 Sand casting method: green sand machine modeling method, self-hardening resin sand modeling core, sodium silicate sand modeling core, dry and surface dry, solid casting, negative pressure modeling, manual modeling.
1.2 Sand core manufacturing method: It is selected according to the size, shape, production batch and specific production conditions of the sand core. In production, it can be divided into manual core making and machine core making as a whole.
2 Special casting, according to the modeling material, can be divided into special casting with natural mineral sand and gravel as the main modeling material (such as investment casting, clay casting, shell casting, negative pressure casting, solid casting, ceramic casting, disappearing) Mold casting, etc.) and special casting with metal as the main mold material (such as metal mold casting, pressure casting, continuous casting, low pressure casting, centrifugal casting, etc.).
2.1 Metal mold casting method
Use a metal with a higher melting point than the raw material to make a mold. Among them, it is subdivided into gravity casting method, low pressure casting method and high pressure casting method. Subject to the melting point of the mold, the metal that can be cast is also limited.
2.2 Dewaxing casting method
This method can be the outer film casting method and the solid casting method.
Copy the object to be cast with wax first, then immerse it in a ceramic-containing bath and wait to dry, so that the wax replica is covered with a ceramic outer film, and the steps are repeated until the outer film is sufficient to support the casting process (about 1/ 4 inch to 1/8 inch), then melt the wax in the mold and pull out of the mold. After that, the mold needs to be heated many times to increase the hardness before it can be used for casting.
This method has good accuracy and can be used for casting of high melting point metals (such as titanium). However, due to the high price of ceramics, and the need for multiple heating and complicated production, the cost is quite expensive.
