Casting is a technical process to melt the metal into liquid which reaches certain requirements and to grout it into the casting mould to get casting parts with predetermined shape, size and properties after cooling, clotting and cleaning processes, and it is the basic process in modern manufacturing industries.
 
Actually casting is a kind of metal hot working process managed by people long ago, and it already has a history over 6000 years. At the very beginning, casting was influenced greatly by pottery, so most of casting parts were used as tools or appliances for agricultural production, religion and lives and so on, and it also had thick art color.
 
There are many kinds of casting types. For example, according to different casting methods, casting can be divided into common sand casting, special casting. Currently aluminum sand casting is widely used at industries since aluminum has good strength properties and excellent casting properties to gain sand casting parts with excellent performance.
 
The casting's blank is cheap in cost, and it can highlight its economical efficiency for those casting parts with complicated shapes and especially with complicated cavity, and at the same time it has wide adaptability with good comprehensive mechanical properties.
 
Forging is a processing method to use metal forming machinery to put pressure on metal blank, making it have permanent deformation in order to gain forging parts with certain mechanical properties, certain shape and size. With the help of forging technology, the loosen cast condition of metal material can be eliminated, and the mechanical properties of forging parts are usually better than casting parts in the same material. Therefore, important parts with high load and rigorous working condition in the machinery will choose forging mostly.
 
According to the forming method, forging is usually divided into open die forging and closed die forging, and it will also be divided into hot forging, warm forging and cold forging based on the deformation temperature.
 
The materials for forging are usually carbon steel, alloy steel and aluminum, magnesium and so on. Therefore, forging is also called metal forging, but forging ration which refers to the ratio between the areas of cross section before and after metal deformation is very important in forging process since the ratio has something to do with improving the quality and reducing the cost.
 
Both casting and forging are widely used in industries, and different parts require different processes, and if we want to get parts with high mechanical properties, maybe forging will be a better choice.