Casting is the act or process of shaping of metal made from a molten material poured into a mold wherein the finished product is similarly called castings. It is used as an alternative to other shaping processes such as machining, forging, welding, rolling, sculpting, boring, carving or other means. Many industries prefer metal casting because of its ability to create complex shapes, both internal and external, and cast repeated copies of mass produced parts.
Metal casting has different types. Sand casting involves making a mold out of a sand mixture and then pouring the liquid metal into the sand hollow of your desired shape. This is suitable for industries looking for large production of products at low cost. There are three variants of sand used in molding. Green sand is composed of silica or olivine sand, bentonite clay, water and other additives blended together. These ingredients are compacted by either squeezing or jolting the mold packed around a wood or metal pattern. Bake mold casting happens when chemical binders are mixed with sand and placed in a mold creating a shape. Another type of sand casting is chemically bonded sands or resin-bonded silica sand. It forms shell-like mold halves after being placed onto a heated pattern. This shell process is used both in mold-making and core making.
Die casting is a type of metal casting wherein molten metal are forced into cavities under high pressure. This process is used for producing large volumes of small or medium sized pieces in which the parts’ details need to be accurate. This involves the use of aluminum, zinc, magnesium and copper.
Permanent mold involves a process that is widely known. A liquid metal is poured into a hole at the top of two halves of mold joined together.
There are many other types of castings aside from sand, die and permanent mold. This shaping process is taken advantage by a lot of industries because of its flexible and low cost production process.