Casting process

Casting technology is the theory and system knowledge relevant to the application of casting production casting techniques and methods. Including the molding materials preparation, modelling, core making, metal melting, pouring and solidification control.
The paper
Casting is poured through melting metal liquid injection mould, the cooling and solidification obtain the required shape and properties of components of the production process. Casting is a common manufacturing methods,
Advantages are: low manufacturing cost and process flexibility, can get complicated shape and large castings, occupies a large proportion in the machinery manufacturing, such as machine tool accounts for 60 to 80%, cars accounted for 25%, tractor accounts for 50 ~ 60%.
Casting is an ancient methods, can be traced back to 6000 years ago in our country. With the development of industrial technology, the quality of the casting of large castings directly affects the quality of the product, as a result, the casting occupies an important position in the mechanical manufacturing industry. Casting technology development is also very rapidly, especially in the late 19th century and the first half of the 20th century, there are many new casting method, such as low pressure casting, ceramic casting, continuous casting, etc., in the second half of the 20th century was perfected and practical application.
Since today the quality of casting, precision casting, casting cost and the improvement of casting automation, etc, casting technology to motors, large-scale, high quality, the direction of automation and clean production, for example our country in recent years in the precision casting, continuous casting, special casting technology, casting automation and casting forming simulation technology has been developing rapidly.
process
Casting the main process includes: metal smelting, model manufacturing, casting solidification and demoulding cleaning, etc. The main material is cast steel, cast iron foundry, casting non-ferrous alloy (copper, aluminum, zinc, lead, etc.), etc.
Gravity casting
Gravity casting is refers to the liquid metal in the earth's gravity injection mold process, also known as casting. Generalized gravity casting sand mold casting, metal mold casting, investment casting, mud casting, etc.; The narrow meaning of gravity casting specifically to metal mold casting.
Pressure casting
Pressure casting is refers to the liquid metal in other external forces (including gravity) under the action of injection mold process. Generalized pressure casting including die casting machine pressure casting and vacuum casting, low pressure casting, centrifugal casting, etc.; Narrow casting are specifically to die casting machine of the metal mold casting, die casting for short. These casting process is the most commonly used in non-ferrous metal casting, is also relative to the lowest price.
Sand casting
Sand casting is a kind of modeling a sand as the main materials, make traditional mould casting process.
Commonly used sand mould gravity casting, when have special requirements, also can use low pressure casting, centrifugal casting, etc. The adaptability of sand mold casting is very wide, small, big, simple and complex parts, single, large quantities of all can use. Sand casting mold, multi-purpose wood before production, known as wood pattern. Block defect is easy to deformation, easy to damage; In addition to the single production of sand mold casting, you can use the dimensional accuracy is higher, and longer service life of aluminum alloy mold or resin mold. Although prices have improved, but still far cheaper than metal mold casting mould, in small batch and bulk production, the price advantage is particularly prominent. In addition, the sand mould is higher than metal mold refractoriness, therefore such as high melting point materials such as copper alloys and ferrous metals also use this technology more. Sand mold casting, however, there are also some disadvantages: because each sand pouring time, can only get after casting mould is damaged, must make a new model, so the production efficiency of sand mold casting is low; And because overall properties of the sand soft and porous, so the casting dimension precision of sand mold casting is low, the surface is rough.