Casting classification

There are mainly two types of sand casting and special casting.

Ordinary sand mold casting uses sand as mold material, also known as sand casting and sand turning, including three types: wet sand mold, dry sand mold and chemically hardened sand mold, but not all sand can be used for casting. The advantage is that the cost is low, because the sand used in the mold can be reused; The disadvantage is that the manufacturing of the mold is time-consuming, and the mold itself cannot be reused, and the finished product can only be obtained after being destroyed.

1.1 sand mold (core) casting method: wet sand mold, resin self hardening sand mold, water glass sand mold, dry mold and surface dry mold, full mold casting, negative pressure molding.

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, generally speaking, it can be divided into manual core making and machine core making.

2 special casting, according to molding materials, can be divided into two types: special casting with natural mineral sands as the main molding materials (such as investment casting, mud mold casting, shell mold casting, negative pressure casting, full mold casting, ceramic mold casting, etc.) and special casting with metals as the main molding materials (such as metal mold casting, pressure casting, continuous casting, low-pressure casting, centrifugal casting, etc.).

2.1 metal mold casting method

A mold is made of a metal having a higher melting point than the raw material. It is subdivided into gravity casting, low-pressure casting and high-pressure casting.

The metal that can be cast is also limited by the melting point of the mold.

2.2 dewaxing casting method

This method can be divided into outer film casting method and solid casting method.

First copy the object to be cast with wax, then immerse it in a pool containing ceramic (or silica sol) and let it dry, so that the copy made with wax is covered with a ceramic outer film, and repeat the steps 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 it out of the mold. After that, the mold needs to be heated for many times to enhance the hardness before it can be cast.

This method has good accuracy and can be used for casting high melting point metals such as titanium. However, due to the high price of ceramics, and the need for multiple heating and complex production, the cost is quite expensive.