History and Types of Casting
– Metal casting has been used throughout history to make tools, weapons, and religious objects.
– Metal casting originated in Southern Asia (China, India, Pakistan).
– Southern Asia traditions relied on statue and relic castings made from a copper alloy laced with lead.
– Simple one to two piece molds were commonly used, but there is evidence of lost wax castings in ancient civilizations.
– The lost wax process originated in ancient Mesopotamia and can be traced back to 4000 BC.
– Casting is a manufacturing process that involves pouring liquid metal into a mold.
– Metal casting is the most common type of casting in metalworking.
– Plaster, concrete, and plastic resin can also be cast using molds.
– Resin casting is a common method for casting plaster, concrete, or plastic resin.
– Different materials and techniques can be used to alter the appearance of the casted objects.
Metal Casting
– Metal casting involves heating metal until it becomes liquid and pouring it into a mold.
– The mold includes the desired shape, runners, and risers.
– The metal solidifies in the mold and the casting is recovered.
– Excess material caused by the casting process is removed in subsequent operations.
– Metal casting has been used to create various objects, including cannons and coins.
Plaster, Concrete, or Plastic Resin Casting
– Plaster, concrete, and plastic resin can be cast using molds.
– Topical treatments like painting and etching can be applied to the surface to give the appearance of metal or stone.
– Colored sand can be added to the casting process to create an appearance of stone.
– Concrete casting allows for the creation of outdoor sculptures, fountains, and seating.
– Chemically-set plastic resins with powdered stone can simulate high-quality marble.
Fettling
– Fettling is the process of removing irregularities and access ports from raw castings.
– It involves cutting, grinding, shaving, or sanding unwanted bits.
– Historically, fettlers performed this work manually, often in dangerous conditions.
– Robotic processes have been developed to perform some parts of the fettling process.
– Designers of molds aim to minimize fettling through mold shape and material considerations.
Lost-Wax Casting
– Lost-wax casting has a long history dating back to ancient times.
– The early history of lost-wax casting can be traced back to South Asia.
– Adriaen de Vries, a sculptor in bronze, played a significant role in the development of lost-wax casting.
– Lost-wax casting was also practiced in Bronze Age China.
– The metallurgy of the earliest lost-wax cast object has been studied using high spatial dynamics-photoluminescence imaging.
– Lost-wax casting is a metalworking technique used to create intricate and detailed objects.
– The process involves creating a wax model, encasing it in a mold, and then melting the wax to leave a cavity.
– Molten metal is then poured into the cavity to create the final cast object.
– Different materials can be used for the mold, such as plaster or ceramic.
– Computer-aided design and analysis have been utilized to improve the precision and efficiency of the casting process. Source: https://en.wikipedia.org/wiki/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 or broken out of the mold to complete the process. Casting materials are usually metals or various time setting materials that cure after mixing two or more components together; examples are epoxy, concrete, plaster and clay. Casting is most often used for making complex shapes that would be otherwise difficult or uneconomical to make by other methods. Heavy equipment like machine tool beds, ships' propellers, etc. can be cast easily in the required size, rather than fabricating by joining several small pieces. Casting is a 7,000-year-old process. The oldest surviving casting is a copper frog from 3200 BC.
