Casting: Molten liquid metal is filled with cavity and cooled. It is easy to produce air holes in the middle of the parts.

The difference between casting and forging:

1. Casting:

1, casting: It is the process of melting the metal into a liquid that meets certain requirements and pouring it into the cast, and getting a casting (part or blank) with a predetermined shape, size and performance after cooling and solidification and cleaning treatment. The basic technology of modern machinery manufacturing industry.

2, the casting production of blank cost is low, for complex shape, especially with complex cavity parts, more can show its economy; At the same time, it has wide adaptability and good comprehensive mechanical properties.

3, but the materials required for casting production (such as metal, wood, fuel, modeling materials, etc.) and equipment (such as metallurgical furnace, sand mixer, molding machine, core making machine, shakeout machine, shot blasting machine, cast iron plate, etc.) more, and will produce dust, harmful gases and noise and pollute the environment.

4, casting is an early human grasp of a metal hot working process, has a history of about 6,000 years. Bronze frog castings appeared in Mesopotamia in 3200 BC. Between the 13th and 10th centuries BC, China has entered the heyday of bronze castings, and the process has reached a very high level, such as the 875 kg Simu Wu square tripod of the Shang Dynasty, the Zeng Hou Yi plate of the Warring States and the light mirror of the Western Han Dynasty are representative products of ancient casting. The early casting was greatly influenced by pottery, and the castings were mostly tools or utensils for agricultural production, religion, life and other aspects, and the artistic color was strong. In 513 BC, China cast the recorded... Cast iron - Jin State cast tripod (about 270 kg). Around the 8th century, Europe began to produce cast iron. After the industrial Revolution in the 18th century, castings entered a new period of service for large industries. Into the 20th century, the development of casting speed is very fast, has developed ductile iron, malleable iron, ultra-low carbon stainless steel and aluminum copper, aluminum silicon, aluminum magnesium alloy, titanium base, nickel base alloy and other casting metal materials, and invented a new process for gray cast iron inoculation treatment. After the 1950s, there were new processes such as wet sand high-pressure modeling, chemical hardening sand modeling and core making, negative pressure modeling, and other special casting and shot blasting.

5, there are many kinds of casting, according to the modeling method is customarily divided into: ① ordinary sand casting, including wet sand, dry sand and chemical hardening sand 3 categories. ② Special casting, according to the modeling materials can be divided into natural mineral sand as the main modeling materials of special casting (such as investment casting, mud casting, casting workshop shell casting, negative pressure casting, solid casting, ceramic casting, etc.) and metal as the main casting materials of special casting (such as metal casting, pressure casting, continuous casting, low pressure casting, centrifugal casting, etc.) two categories.

Two, forging:

1, forging: is the use of forging machinery to exert pressure on the metal blank, so that it produces plastic deformation to obtain a certain mechanical properties, a certain shape and size of the forging processing method.

2, one of the two components of forging. Through forging can eliminate the metal as cast loose, welded holes, the mechanical properties of forgings are generally better than the same material castings. For important parts with high load and severe working conditions in machinery, forgings are mostly used in addition to the simple plates, profiles or welding parts that can be rolled.

3, forging according to the forming method can be divided into: ① open forging (free forging). Use impact force or pressure to deform the metal between the upper and lower iron (anvil block) to obtain the required forgings, mainly manual forging and mechanical forging two kinds. ② Closed mode forging. The metal blank is compressed and deformed in the forging die with a certain shape to obtain forging, which can be divided into die forging, cold heading, rotary forging, extrusion and so on. Forging according to deformation temperature can be divided into hot forging (processing temperature is higher than the recrystallization temperature of the billet metal), warm forging (lower than the recrystallization temperature) and cold forging (normal temperature).

4, forging materials are mainly carbon steel and alloy steel of various components, followed by aluminum, magnesium, titanium, copper and their alloys. The original state of the material includes bars, ingots, metal powder and liquid metal. The ratio of the transverse area of the metal before deformation to the die area after deformation is called the forging ratio. The correct choice of forging ratio has a great relationship with improving product quality and reducing cost.