Direct Chill

casting Casting is a manufacturing process in which a liquid material is usually poured into a mold, which contains a hollow cavity of the desired shape, and then allowed to solidify. The solidified part is also known as a ''casting'', which is ejected ...

is a method for the fabrication of cylindrical or rectangular solid ingots from non-ferrous metals, especially

Aluminum Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. It has ...

Copper Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkis ...

Magnesium Magnesium is a chemical element with the symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 of the periodic ta ...

and their

alloys An alloy is a mixture of chemical elements of which at least one is a metal. Unlike chemical compounds with metallic bases, an alloy will retain all the properties of a metal in the resulting material, such as electrical conductivity, ductility, ...

. The original ingots are usually further processed by other methods (

rolling Rolling is a type of motion that combines rotation (commonly, of an axially symmetric object) and translation of that object with respect to a surface (either one or the other moves), such that, if ideal conditions exist, the two are in contact ...

forging Forging is a manufacturing process involving the shaping of metal using localized compressive forces. The blows are delivered with a hammer (often a power hammer) or a die. Forging is often classified according to the temperature at which i ...

, etc.). More than half of global aluminum production uses the Direct Chill casting process.Dr. Dmitri Kopeliovich, Direct Chill (DC) casting, http://www.substech.com/dokuwiki/doku.php?id=direct_chill_dc_casting Direct Chill casting operates by pouring liquid metal continuously into a short mold (7.5–15 cm deep) that is open at the bottom. Only an outer layer of metal solidifies within the water-cooled mold. After leaving the closed mold at its bottom (e.g. with 5–15 cm/min), water is directly sprayed on the new ingot, continuing the solidification until complete. Only about 20% of the heat of the molten metal is removed through the mold wall, the secondary cooling (Direct Chill) contributing the majority of cooling. Typically the process is started with a starter-dummy block at the bottom of the mold, and runs until the maximum length possible in the machine is reached (up to 10 m). The casting method reduces the internal stress in the cooled material by allowing contractions on all sides, as opposed to only on the top of the ingot in a traditional trough mold.

References

{{reflist, 30em Casting (manufacturing)