Knowledge

Definition Of Casting

Casting is the process of melting metal into liquid that meets specific requirements and pouring it into the casting mold. After cooling, solidification, and cleaning treatment, the casting with a predetermined shape, size, and performance is obtained. As the rough casting part is almost formed, it can achieve the purpose of no machining or small machining, which reduces the cost and the production time to a certain extent. Casting is one of the basic technologies of the modern device manufacturing industry.

Common Casting Metal

1. Gray cast iron

2. Ductile iron

3. Malleable cast iron

4. The cast steel

Common Used Non-Ferrous Metals For Casting:

1. The brass

2. Tin bronze

3. Wuxi Bronze

4. Aluminum alloy

Casting Classification:

1. Ordinary sand casting, which uses sand as a mold material, includes three categories: wet sand, dry sand, and chemically hardened sand, but not all sands can be used for casting. The advantage is that the cost is lower because the sand used in the casting mold can be reused; the disadvantage is that the casting mold is time-consuming, the casting mold itself cannot be reused, and the finished product can only be obtained after the casting mold is destroyed.

2. The metal mold casting method uses metal with a higher melting point than the raw material to make a mold. It is subdivided into gravity casting method, low-pressure casting method, and high-pressure casting method. The disadvantage is that it is limited by the melting point of the mold, and the metal that can be cast is also limited.

3. Lost wax casting method, first use wax to replicate the object to be cast, then immerse it in a pool containing ceramic (or silica sol) and wait for it to solidify, so that the wax replica is covered with a ceramic outer film. Repeat this step until the outer film is large enough to support the casting process (about 1/4" to 1/8"), then melt the wax in the mold and pull it away from the mold. After that, the mold needs to be subjected to high-temperature many times, and the hardness can be increased before it can be used for casting. High accuracy, but high cost.

Process Classification

1. Sand casting, which is also divided into tidal sand casting (mechanized modeling), resin self-hardening sand casting, sodium silicate self-hardening sand casting, and sand covering modeling casting.

2. Precision casting, also known as lost wax casting, investment casting

3. Lost mold casting

4. Die casting, also known as pressure casting

5. Centrifugal casting

6. Gypsum casting

7. Continuous casting