Advantages of the Casting Process

List some of the inherent advantages of using the metal casting process.

Basic Steps of the Casting Process

Getting the Casting Geometry

Mold Making

Core Making

Molding

Melting and Pouring

Sweeping

Mold Making

The pattern is the physical model of the casting from which the mold is made.

The mold is made by wrapping some easily moldable aggregate, such as molding sand, around the pattern. When the pattern is removed, its impression forms the mold cavity, which is eventually filled with metal to form the casting.

If the casting is hollow, such as a pipe, additional patterns called cores are needed to form these

cavities.

Core Making

A core is a mold, usually made of sand, that is placed into the mold cavity to form the inner surface of the casting. Thus, the space between the core and the cavity surface eventually becomes the casting.

Molding

Molding includes all the operations required to prepare the mold to receive molten metal. Molding usually involves placing molding aggregate around the pattern held in place by a support frame, pulling the pattern out of the mold cavity, setting the core in the mold cavity, and then completing and closing the mold.

Melting and Pouring

The process of preparing molten metal for casting is simply called melting. Melting is usually done in a specially designated area of the foundry, and the molten metal is then transferred to the pouring area where the mold is filled.

Sweeping

Sweeping refers to all operations required to remove sand, scale, and excess metal from the casting. The casting is separated from the mold and transported to the sweeping department. Burnt sand and scale are removed to improve the surface appearance of the casting. Excess metal such as fins, wires, parting line fins, and gates are removed. Castings can be upgraded by welding or other procedures. Castings are inspected for defects and overall quality.