C.i.casting Part

1. Green Sand Process
A A A A A A A InA sand casting, the mold is formed around a pattern by ramming sand, mixed with the proper bonding agent, onto the pattern. Then the pattern is removed, leaving a cavity in the shape of the casting to be made. Molten metal is poured into the mold, and after it has solidified the mold is broken to remove the casting. In making molds and cores, various agents can be used for bonding the sand. The agent most often used is a mixture of clay and water.

2. Dry Sand Process
A A A A A large components are very difficult to cast to exact size and dimensions. Hence, some foundries use dry sand molds to produce such parts. Dry sand molding is the green sand process modified by baking the mold at prescribed temperature. Engine blocks, large gears, big housings, construction parts, are examples of dry sand process candidates. Ferrous and non-ferrous metals are cast in this method.

3. Co2 Process
A A A A A A process for hardening molds or cores in which carbon dioxide gas is blown through dry clay-free silica sand to precipitate silica in the form of a gel from the sodium silicate binder. See Silica Sand.

4. Shell Process
A A A A A Process in which clay-free silica sand coated with a thermosetting resin or mixed with resin is placed on a heated metal pattern for a short period of time to form a partially hardened shell. The bulk of the sand mixture inside the resulting shell is removed for further use. The pattern and shell are then heated further t