Casting is a process by which a metal or other alloy substance is melted, poured into a specific mold, cooled, and solidified to form a part or product of the desired shape. Casting is a common processing technique in the manufacturing industry that can produce products of various sizes and shapes from small components to significant industrial components, such as vehicle engine parts, building components, machine parts, etc. According to the different molding methods, casting can be divided into 8 types.
Sand casting
Sand casting is a standard method of metal casting, typically used to produce small to medium-sized castings. The basic principle of this method is to pour molten metal into a single-use, reusable mold (usually made of sand), wait for it to cool and take shape, and then remove the casting from the mold.
The process of making a mold usually involves adding wet sand, clay, or other material to the mold, then filling it completely and smoothing it out. Next, you need to make holes in the mold or place a model of the casting, which will determine the shape of the final casting. The molten metal is then poured into a mold, which is allowed to cool and form after being held long enough to ensure the metal fills the entire mold. Once formed, the casting is removed from the mold, cut, ground, and cleaned for different applications.
Sand casting features:
- Low precision: Due to the mold's inaccuracy and the sand mold's deformation, the precision of conventional sand castings is low, and the accuracy can reach up to 0.05mm.
- The wide applicability of materials: The sand casting method is suitable for the casting of various metals and alloys, including iron, steel, copper, aluminum, and their alloys.
- Flexible modeling: Since the mold is made of sand, workpieces of various shapes can be produced, and the mold can be modified quickly.
- Low cost: Compared with other processes, the cost of sand casting is lower, especially when casting a large number of workpieces.
Sand casting application:
- Sand casting is widely used in automobiles, aerospace, machine tools, rail transit, electronic equipment, construction, and other fields to produce various simple or complex castings.
- Sand casting is also widely used in the manufacture of heavy machinery such as pressure vessels, boilers, fans, cement machinery, mining equipment, and agricultural machinery.
- Sand casting is also suitable for making artwork, statues, casting models and handicrafts, etc.
Investment casting
Investment casting is a time-consuming and complicated metal casting process suitable for high precision, high surface quality, and complex shapes. It first puts the model in a solution of high temperature and inorganic compounds to form a high temperature-resistant, pressure-resistant, and wear-resistant ceramic shell, and then dries and hardens it, then melts the casting material, injects it into the shell, waits for the casting to cool. , the shell is crushed chemically or mechanically, and the final casting is obtained. This process can produce parts with high dimensional accuracy, high surface finish, complex internal structures, and thin walls that are difficult to process and is especially suitable for the production of high-end parts in aviation, aerospace, automobile, machinery, and other industries.
Investment casting (investment casting) is a high-precision, high-complexity casting process. Its characteristics include the following points:
- High precision: obtain high-precision castings, the dimensional accuracy can reach 0.05mm/cm, and the surface finish is high.
- High complexity: parts of various shapes, precision, and complexity can be manufactured.
- High cost: Compared with other casting processes, the investment cost is high, but in the long run, better performance and lower net cost can be obtained.
Investment casting is widely used, mainly in aviation, aerospace, nuclear energy, medical treatment, rail transit, automobile, shipbuilding, metallurgy, chemical industry, etc. Among them, high-end fields such as aviation, aerospace, and nuclear energy have high requirements for precision, strength, high-temperature resistance, corrosion resistance, and light weight of parts, so investment casting is the preferred process. At the same time, medical, automotive, chemical, and other fields have high requirements for materials, and investment in casting can provide high material purity, reliability, and safety.
Die casting
Die casting is an efficient metal-forming process that enables the rapid manufacture of complex metal parts by pressing molten metal into molds. Common metal materials include zinc alloy, aluminum alloy, magnesium alloy, etc.
feature:
- Die casting can quickly manufacture complex metal parts with high precision and high consistency.
- The production efficiency is high, and the manufacture of large quantities of parts can be completed in a short time.
- Die casting can achieve design flexibility through mold technology to adapt to different production requirements and application fields.
application:
The main applications of die casting include automotive, aerospace, electronics, medical equipment, and other fields. For example, automotive engine parts, aerospace components, electronic equipment housings, etc. In these fields, die casting is widely used in the manufacture of complex parts with high-tech content.
Centrifugal casting
Centrifugal casting is a centrifugal process characterized by casting molten metal or other material in rapidly rotating molds. Since this process can form high-speed eddy currents in the mold, it can make the surface quality of the castings higher, and at the same time, it can effectively avoid the internal defects of the castings. Centrifugal casting has a wide range of applications, and common fields include aviation, automobile, construction, petrochemical, and textile industries. Castings of complex shapes such as pipes, gears, hubs, bearings, etc. can be produced through this process. Compared with other casting processes, Centrifugal casting has higher production efficiency, can produce larger castings, and the quality is more reliable.
Continuous casting
Continuous casting is a casting process in which molten metal is directly cast into a continuous strip billet. This technology can make steel production more automated, and can also improve production efficiency and product quality.
The main feature of Continuous casting is that by continuously injecting molten metal, the caster can continuously produce high-quality metal billets. During the casting process, molten metal passes through a series of continuous cooling zones, and different control and heating techniques are used to control the temperature and shape of the billet.
Continuous casting is widely used in popular and precision manufacturing. For example, it can be used to produce billets of materials such as steel, aluminum, and copper, and is used to manufacture products such as automobiles, electronic equipment, and construction materials.
In addition, Continuous casting also brings some other advantages. For example, this process can save a lot of materials and energy, and reduce pollution and waste. At the same time, it can also improve the quality and uniformity of the product, thereby reducing the occurrence rate of substandard products, and can also meet various customer needs.
Shell molding casting
Shell molding casting is a precision casting process that applies the chemical unit method of hardened mortar on the surface of a heated metal mold to form a shell with a thickness of about 10 mm, and then injects molten metal from the top or side and waits for the metal to solidify, and the shell is released from the mold to obtain the final casting.
feature:
- High precision: the formation of the shell and the solidification process of the casting are very precise, the surface finish of the casting is high, there are no pores, and there are very few defects.
- High quality: The chemical composition of leather castings is uniform, and can achieve the same mechanical performance indicators as forgings.
- Wide adaptability: It is suitable for casting aluminum alloy, copper alloy, iron alloy, and other materials, and can manufacture high-quality and complex castings.
application:
Shell mold casting can be used to manufacture parts of automobiles and aero engines, turbine impellers, water pump and compressor parts, motor housings, textile machinery, medical equipment, and military and other industrial fields that require high-precision and high-quality castings.
Lost foam casting
Lost foam casting is a new type of casting process. Its working principle is to mold the foam plastic into the shell of the casting, and then pour the cast metal into the mold to fill the cavity of the mold, and finally form the required casting.
The characteristic of Lost foam casting is that it can quickly produce high-precision complex shape parts, avoiding the process of mold making and cleaning in traditional casting, saving cost and time. At the same time, this process can also realize the one-time casting of multiple assemblies and improve work efficiency.
Lost foam casting is mainly used in the casting process of automobiles, machine tools, ships, electric power, and other fields. In the manufacture of auto parts, the use of this process can effectively solve the problems of low part precision, material waste, and low production efficiency, and improve the quality and production efficiency of parts; Precision, and large castings, greatly saving manufacturing costs and time.
Permanent mold casting
Permanent mold casting is a metal casting process that uses metal molds for casting. Commonly used mold materials include cast iron, steel, etc. In this process, the mold is not single-use like traditional casting, "permanent" means that the mold can continue to be used, with frequent cleaning and reconditioning to maintain its precision and surface smoothness.
feature:
- High production efficiency - the mold can be reused, which improves production efficiency.
- High precision - due to the use of metal molds, the accuracy of its surface topology, roughness, etc. will be higher, and there will be almost no residual substances from the mold surface to pollute the casting surface.
- Low scrap rate - compared to other casting methods such as sand casting or lost wax casting, the scrap rate is very low.
- Can cast high melting point alloys and superalloys - permanent type casting is suitable for various types of alloys and superalloys.
application:
- Manufacturing of auto parts - permanent mold casting is widely used in the manufacture of various auto parts, such as steering gears, transmission housings, cylinder blocks, etc.
- Tools, Construction Parts - Permanent mold casting is also suitable for the manufacture of various tools and construction parts.
- Aerospace parts - Since permanent mold casting can produce superalloy, high-impact derivative parts, it is very suitable for manufacturing aerospace components.
- Other Mechanical Parts – Titanium alloys are of a higher grade than other alloys. Permanent type casting is suitable for the manufacture of various mechanical parts such as engine components, pumps, weapon parts, etc.