Casting Manufacturing Processes
Casting Manufacturing Processes
Brief Description of Casting
Casting is a manufacturing process in which a liquid material is filled into a mould, 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 or broken out of the mould to complete the process. Casting materials are usually metals or various time setting materials that vary depending on which casting process. Casting is most often used for making complex shapes that would be otherwise difficult or uneconomical to make by other manufacturing methods.
Centrifugal Casting
Centrifugal casting is generally used to manufacture pipes by pouring molten metal in to a rotating mould using centrifugal force to move the molten metal to outer of the mould. It can be used for other castings using semi-centrifugal casting.
Continuous Casting
Continuous casting also known as strand casting, is a process where molten metal is poured into chilled moulds and solidified into a semi-finished state such as a billet, bloom or slab. These billets, blooms or slabs are send to the finishing mills for rolling.
Die Casting
Die casting is a casting process that is characterised by forcing molten metal under high pressure into a mould cavity. The mould cavity is created using two hardened tool steel dies which have been machined into shape and work.
Investment Casting
Investment casting is an industrial process based on lost was casting, one of the oldest known metal forming techniques. The term "lost-wax casting" can also refer to modern investment casting processes.
Permanent Mould Casting
During permanent mould casting, raw material is placed into the cavity of
a permanent mould. After the raw material has cooled and hardened, the
casting is removed from the mould cavity and the mould is then reused.
Resin Casting
Resin casting is a method of resin casting where a a mould typically a silicone mould is filled with a a liquid synthetic resin which hardens. It is primarily used for small-scale production like industrial prototypes, dentistry and jewellery.
Sand Casting
Sand casting, also known as sand moulding, is a metal casting process characterised by using sand as the mould material. Over 60% of all metal castings are produced via sand casting process.
Evaporative Pattern Casting
Evaporative pattern casting is a sand casting process that uses foam to form a replica of an item in order to evaporate in a sand mould in replacement of molten metal. This casting process is also known as consumable, it is similar to investment casting.
Casting History - Timelines
Early Metal Casting
- 9000 B.C.-Earliest metal objects of wrought native copper are produced in the Near East.
- 3000-2500 B.C.-Small objects are cast via lost wax (investment casting) process in the Near East.
- 3200 B.C.-The oldest casting in existence, a copper frog, is cast in Mesopotamia.
- 3000 B.C.-Early foundrymen cast bronze tools and weapons in permanent stone moulds.
- 1500 B.C.-Wrought iron is discovered in the Near East.
- 600 B.C.-The first cast iron object, a 600-lb tripod, is cast by the Chinese.
- 233 B.C- Iron plowshares are cast.
- 200 B.C.-Oldest iron castings still in existence are produced during the Han Dynasty.
The Middle Ages
- 1455 - The inaugural cast iron pipe is made in Dillenburg Castle in Germany. It was used to transport water from one place to the next.
- 1480 - Vannoccio Biringuccio, known as the father of the foundry industry by many, is the first person to record his methodology in writing.
- 1642 - Saugus Iron Works is established in Lynn, MA. The United States’ first iron foundry was home of the very first American iron casting, the Saugus pot.
- Early 1700s - The Brit Abraham Darby makes the original foundry flask for san and loam molding. Darby also was the first person to use coke, a coal derivative that occurs from the distillation of bituminous coal without the presence of air, at his metal furnace in Coalbrookdale, England.
- 1750 - Benjamin Huntsman duplicates the process of cast crucible steel. This process involves melting steel, which results in a uniform composition of the molten steel. This affords the ability to produce alloy steel because the necessary elements for casting an alloy can be included in the crucible while the steel is molten. Previously, steel had never reached a molten state.
- 1794 - The Cupola is used for the first time in iron founding, a process invested by John Wilkinson.