METAL CASTING PROCESS: TYPES, ADVANTAGES, STAGES, USES
The metal casting process is the oldest and popular method of manufacturing means of designing the desired shapes. It is the first step in manufacturing most products.
Casting is made from any metal that can be melted and can have any shape the designer desires. The castings can produce in sizes ranging from a few mm to several meters. Casting can weigh from a few grams to tons.
Products with very complex shapes, hollow sections, complex internal cavities, and irregularly curved surfaces made of metals that are difficult to machine can be easily produced by the casting process.
Many casting processes are available and the choice of a process for producing particular parts depends on such factors as production cost, production rate, size, shape, and surface finish. The casting processes differ from each other basically in the type of material used for the preparation of the mould and the method of pouring the molten material.
The mould material is generally sand or metal and the pouring method may use gravity, vacuum, low or high pressure. Casting is most often used for making complex shapes that would be difficult or uneconomical to make by other methods.
The modern casting process is divided into two main categories:
In expendable casting, it includes sand casting, shell casting, plaster mould casting, investment casting, and evaporative-pattern casting.
In non-expendable casting, it includes permanent mould casting, dies casting, semi-solid metal casting, centrifugal casting, continuous casting.