ã€China Aluminum Industry Network】 1. Introduction Wheels, also known as rims, are cylindrical, center-mounted metal parts that support the tire's inner profile. The parameters are as shown below: Second, according to material classification Hubs are mainly divided into steel hubs and light alloy wheels according to the materials, while the light alloy wheels are mainly aluminum alloy and magnesium alloy products. In today's automotive market, steel wheels are rare, and most models use aluminum alloy wheels, light alloy wheels. Aluminum alloy materials used in the manufacture of aluminum hubs include A356, 6061, and the like. Among them, A356 has been selected for a large number of cast aluminum wheels. A356 aluminum alloy has the characteristics of small specific gravity and good corrosion resistance, mainly composed of aluminum, silicon, magnesium, iron, manganese, zinc, copper, titanium and other metal elements. Aluminum accounts for about 92%, and is a mature aluminum alloy. material. Third, the production process of aluminum alloy wheels Aluminum alloy wheels are more suitable for passenger cars than steel wheels. At present, its manufacturing process can be basically divided into three types. The former is the casting. Most of the current automotive manufacturers have chosen to use the casting process. The second is forging, which is mostly used in high-end sports cars, high-performance cars and high-end conversion markets. The third kind is more special. It is the MAT spinning technology that was put into use earlier by Japanese Enkei Company. At present, the application of this technology in China is not as good as the first two. The method has low cost, simple process and high production efficiency. However, during the casting process, inclusions are easily entangled in the castings, and gas may sometimes be trapped to form porosity defects. Wheels produced by gravity casting are prone to shrinkage and shrinkage and have poor internal quality. In addition, restrictions on the fluidity of aluminum fluids may also result in low wheel yields for complex shapes. Therefore, automotive hub manufacturing has rarely used this technology. 3. Forging method Hot forging→RM forging→Cold spinning→Heat treatment→Machine work→Shot blast→Surface finishing Forging is a solid-to-solid change. The hub pattern is formed by means of slap, press, forge, etc. This process does not occur in the liquid phase but changes in solids. Therefore, its mechanical properties are higher than that of casting, and it has the advantages of high strength, good corrosion resistance, and accurate dimensions. Grain flow direction is consistent with the direction of force, so strength, toughness and fatigue strength are significantly better than cast aluminum wheels. At the same time, the typical elongation of a forged aluminum hub is 12% to 17%, so it can absorb road vibrations and stress well. In addition, the surface of the forged aluminum hub is non-porous, so it has a very good surface treatment capability. However, the major disadvantage of forged aluminum hubs is the large number of production processes and the production costs are much higher than that of the cast. Although the performance of forged wheels is better, automakers still use casting wheels in most vehicles. Only a few luxury cars are equipped with forged wheels. However, CITIC Decker, a leading domestic hub manufacturing company, has successfully entered the passenger car forged wheel hub production line and reduced the cost of forged wheels to RMB 1,000, and has begun to supply domestic joint ventures as the original hub. 4. Squeeze casting method Squeeze casting, also known as liquid forging, is a process that combines the characteristics of casting and forging - pouring a quantity of metal liquid directly into an open metal mold and applying a certain pressure on the liquid metal through the punch. , to make it filled, shaped and crystallized and solidified, and to produce a certain amount of plastic deformation during the crystallization process. Advantages: Smooth mold filling, the metal is crystallized and solidified directly under pressure, so the casting will not produce casting defects such as pores, shrinkage holes and shrinkage, etc., and the structure is dense, the mechanical performance is higher than that of the low pressure casting parts and the investment is much lower than the low pressure casting method. Disadvantages: As with traditional forged products, it requires milling to complete the spokes. In Japan, a considerable number of automotive aluminum wheels are produced using the squeeze casting process. The entire process from pouring the molten metal to removing the casting is controlled by a computer, and the degree of automation is very high. At present, all countries in the world use squeeze casting as one of the directions for the production of automobile aluminum wheels. Figure: Schematic diagram of hub extrusion casting process 5. Special molding: MAT spinning technology MAT spinning technology was put into use earlier by Japanese Enkei company. Strictly speaking, it should be considered as a kind of casting. It refers to the use of special equipment to rotate and pressurize the bearing after the wheel is cast. The internal molecular arrangement of the metal in the treated position is changed, and the specific split surface presents a denser fibrous structure than the general cast product, thereby changing the overall metal mechanics process method. The mass, strength and extensibility of the hub manufactured by MAT spinning technology are close to those of forged wheels, and are now easier for forged wheels. In general, the MAT spinning technology can relatively ensure the manufacturing cost of the hub, and at the same time, it can also make the cast hub create similar weight and strength to the forged hub. Only the domestic technology is immature and the cost is high, so the application is not much. Picture: Enkei Racing Revolution Series RS05RR Wheels with MAT Spinning Technology Fourth, famous wheel brand 1.RAYS (Japan-Korea Department) Japan's famous hub manufacturers, the products produced are typical Japanese wheels, almost all Japanese models can find the corresponding parameters of the modified wheels. Japanese and Korean wheel hub brands are also abundant. Similar brands to RAYS include WORK, ADVAN, ENKEI, and BuddyClub. 2.BBS (Germany) Headquartered in Germany, original supplier of BMW, Audi, Porsche, Volkswagen, Mercedes-Benz, Land Rover and other auto brands; Ferrari and Maserati sports car hub suppliers. 3.OZ ​​(Europe and the United States) The famous wheel manufacturers in Italy provide a variety of wheel products to the major car brands including Volkswagen, Mercedes Benz, Jaguar, Alfa Romeo, Ford, Lotus, Suzuki, etc., making OZ a household name. It sponsors and supports a variety of international auto races such as the F1 Drivers Grand Prix. 4.TWG (The Wheel Group·Europe and the United States) One of the larger automotive dealerships in the United States, headquartered in Los Angeles, USA. Its 12 brands include the high-end luxury series Baccarat, Mazzi, Veloche, and Touren, as well as Ion, Akita, DIP, Sacchi, Detroit, MPW, Ridler, and Mayhem, which are positioned in the mid-market. The product sizes cover all passenger car needs. 5. CITIC Daica (Homemade) The leading brand of domestic wheels - the world's largest supplier of aluminum wheels and aluminum chassis parts; the domestic auto parts industry exports the front; aluminum wheel annual output reached 35 million, there is one aluminum wheel every second off the assembly line , The global supporting 8 million vehicles. GUANGDONG LAVIUS LIGHTING CO., LTD. , https://www.laviuslighting.com
1. Gravity Casting Gravity Casting Simply put, mainly by relying on the gravity of aluminum water to fill the mold, is an earlier method of casting. 
2. Low-pressure casting method Low-pressure casting is a process in which aluminum liquid is charged into a mold under pressure and solidification and crystallization is performed under pressure. In the same situation, compared with gravity casting, the internal structure of the low-pressure casting hub is denser and stronger. In addition, low-pressure casting utilizes pressure filling and replenishment, which greatly simplifies the structure of the tumbling system and enables the liquid metal recovery rate to reach 90%. At present, low-pressure casting has become the preferred process for the production of aluminum wheels. Most domestic aluminum wheel hub manufacturers use this process to produce. However, the low-pressure casting method also has its disadvantages: long casting time, long time for feeding, changing molds, and investment in equipment. 
