Centrifugal casting (industrial)

Centrifugal casting or rotocasting is a casting technique that is typically used to cast thin-walled cylinders. It is used to cast such materials as metal, glass, and concrete. It is noted for the high quality of the results attainable, particularly for precise control of their metallurgy and crystal structure. Unlike most other casting techniques, centrifugal casting is chiefly used to manufacture stock materials in standard sizes for further machining, rather than shaped parts tailored to a particular end-use.

Typical materials that can be cast with this process are iron, steel, stainless steels, glass, and alloys of aluminum, copper and nickel.

Two materials can be cast together by introducing a second material during the process.

Typical parts made by this process are pipes, flywheels, cylinder liners and other parts that are axi-symmetric. It is notably used to cast cylinder liners and sleeve valves for piston engines, parts which could not be reliably manufactured otherwise.

Cylinders and shapes with rotational symmetry are most commonly cast by this technique. "Tall" castings (in the direction of the settling force acting, usually gravity) are always more difficult than short castings. In the centrifugal casting technique the radius of the rotation, along which the centrifugal force acts, replaces the vertical axis. The casting machine may be rotated to place this in any convenient orientation, relative to gravity's vertical. Horizontal and vertical axis machines are both used, simply to place the casting's longest dimension conveniently horizontal.

Thin-walled cylinders are difficult to cast by other means, but centrifugal casting is particularly suited to them. To the rotation radius, these are effectively shallow flat castings and are thus simple.

Centrifugal casting is also applied to the casting of disk and cylindrical shaped objects such as railway carriage wheels or machine fittings where the grain, flow, and balance are important to the durability and utility of the finished product.

Providing that the shape is relatively constant in radius, noncircular shapes may also be cast.

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