Casting may be defined as the production of a desired shape by introducing a molten material into a previously prepared cavity and allowing it to solidity. The metals most frequently cast are iron, steel, aluminum, magnesium, some copper alloys, and certain zinc alloys.
Although the craft is an one, modern casting methods frequently involve precise science and highly skilled engineering. An example is the one V8 engine block cast from aluminum or gray iron, with cylinder chambers and water jackets formed by the many intricate cores set in the mold and holding wall thicknesses within close dimensional accuracy.
Casting is the fastest method for producing complex shapes from raw materials that can be temporarily liquefied by heat or chemical means. Sand casting accounts for some 95% by weight of all metal cast. The fluid material is poured or forced into a shaped cavity called a mold or die. After it has solidified, the casting is removed from the mold. In sand casting the mold is destroyed after one use, but molds for many materials are reuable.
The materials to be cast, the volume of production, and the requirements of the functional design all affect the selection of the mold material an design, and largely determine the other tooling required. For nonmetallic castings, the moet.lds are usually made from gray iron or steel, cast, machined from blocks, or formed from sheet.
Good casting design dictates the use of as uniform a wall thickness as possible, or one that tapers slightly from the thinnest section remote from the gate to the heaviest section at gate. In addition, alloy fluidity dictates the minimum practial wall thickness for each die castable metal.
Minimum Wall Thickness For Die Casting
Surface are in2 : Up to 3.9
Tin, Lead, Zinc : 0.0236-0.0394
Aluminum, Magnesium : 0.0315-0.0471
Copper : 0.0589-0.0787
Surface area in2 : 4.0-15.5
Tin, Lead, Zinc : 0.0395-0.0589
Aluminum, Magnesium : 0.0472-0.0707
Copper : 0.0788-0.0982
Surface area in2 : 15.6-77.5
Tin, Lead, Zinc : 0.0590-0.0787
Aluminum, Magnesium : 0.0708-0.0982
Copper : 0.0983-0.118
Surface area in2 : Over 77.6
Tin, Lead, Zinc : 0.0788-00982
Aluminum, Magnesium : 0.0983-0.118
Copper : 0.119-0.157
No comments:
Post a Comment