Seven typical production processes for aluminum wheels
[China Aluminium Network] wheels, alias wheel, that is, the inner shape of the tire to support the tire barrel shape, the center of the assembly on the shaft. Common car wheels have steel wheels and aluminum alloy wheels. Steel hubs have high strength and are often used in large-sized trucks. However, steel hubs are heavy and have a single shape. They are not in line with today's low-carbon and fashionable concepts and are gradually being replaced by aluminum alloy wheels. The original wheels of passenger cars on the market are basically aluminum alloy wheels. Bolts available from TS Hardware include a comprehensive range of threaded bolts, screws, studs and other essential components used for construction and industrial applications. We manufacture and supply bolts in an extensive selection of sizes, types and materials, including TC Bolts, sheer studs, self drilling screws, and more. We can provide our customers with virtually any type of bolt they need and serve as a one-stop-shop for construction and building components. Carbon Steel Bolt,High Carbon Steel Bolts,Carbon Steel Nuts,Carbon Steel Wedge Anchor Taizhou TS HARDWARE Co., Ltd , https://www.shuwengroup.com
The production process of aluminum alloy hubs mainly includes the following types:
1. Gravity casting Metal gravity casting refers to a casting method in which a liquid metal is filled with a metal mold by gravity to obtain a casting under normal pressure, which is also an ancient casting method. Because the cooling rate of the metal liquid in the metal mold is faster, the casting is denser than the sand casting. This method has simple procedures, high production efficiency, low equipment investment, and low production cost, and is suitable for small and medium-scale production. However, the internal quality of the aluminum hub produced by this method is poor and shrinkage holes are loose and loose. In the casting process, inclusions such as oxide film and slag are easily involved in the casting, and sometimes they are entrained in gas to form porosity defects, and the liquid metal is collected. The yield is also low. Most of the OEMs have now rejected the wheels produced by this process and are gradually becoming marginalized in the aluminum wheel manufacturing industry.
2. Low-pressure casting The low-pressure casting is to place the mold on a closed furnace, and the lower part of the cavity is connected to a metal liquid phase in the furnace by a pipe (called a liquid riser). If pressurized air is added to the metal surface of the furnace, molten metal will flow from the riser into the cavity. After the molten metal solidifies, the compressed air in the furnace is released and the unsolidified metal flows back from the liquid riser to the furnace. By controlling the pressure and velocity of the air flowing into the furnace, it is possible to control the velocity and pressure of the metal flowing into the cavity, and to allow the metal to crystallize under pressure. This process is characterized by the crystallization of the casting under pressure, dense structure, good mechanical properties and high metal utilization.
The low-pressure casting process is currently quite mature in mainland China. It is suitable for low-person production management and has been recognized by all automakers as the mainstream process for manufacturing aluminum wheel hubs in mainland China. The products are mainly sold to OEMs and overseas retail markets.
Aluminum alloy wheels manufactured by low-pressure casting process have spokes that are cooled and solidified later. Therefore, the spokes of some special-shaped hubs are prone to shrinkage and other quality problems, while the rim parts have better strength due to earlier crystallization.
3. Squeeze Casting Method Squeeze casting, also known as liquid die forging, is a new process that integrates the characteristics of casting and forging. The process involves pouring a certain amount of metal liquid directly into an open metal mold and passing through. The head acts on the liquid metal with a certain pressure, so that it is filled, shaped and crystallized and solidified, and a certain amount of plastic deformation is generated during the crystallization process. Squeeze casting is stable, there is no turbulence and no wrapping gas, 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, grain refinement, mechanical properties. Higher than low pressure castings. The products have excellent mechanical properties close to the forgings, high efficiency and high precision with precision forming of the precision castings, and the investment is much lower than the low pressure casting method. The disadvantage is that liquid forging products, like traditional forged products, require milling to finish the spokes.
In Japan, a considerable number of automotive aluminum wheels are produced using the squeeze casting process. Toyota Motor Co., Ltd. has more than ten fully-automatic squeeze casting equipment. Each piece of equipment can produce an aluminum wheel in less than 2 minutes, from pouring the molten metal to removal. The entire process of castings is controlled by computers and the degree of automation is very high. China has also built a modern aluminum alloy wheel hub plant for squeeze-casting in Guangdong. It has produced aluminum wheels of various specifications and models, and the quality of its products has reached the advanced level of similar foreign products. At present, all countries in the world use squeeze casting as one of the directions for the production of automobile aluminum wheels.
4, casting spin-casting spin "low pressure casting + spinning" and "gravity casting + spinning" two processes. At present, the Korean automotive companies have adopted the trend of “low pressure casting + spinning†in the molding process of aluminum wheels. There are also other products in this series that are in demand for this process. This process is the mainstream process in the casting process and is used as an OEM product. Most of the companies are using this kind of process; at the same time, a small number of companies that do overseas retail markets adopt the "gravity casting + spinning" process, and in theory this process is straightforward and it really puts The strengths of gravity casting and spinning are combined and the product quality is improved. However, because the blank is produced by the gravity casting process, the economics of this process are very poor and the production cost is high. In a word, the product of casting screw, because the spoke part is cast out, it has the same advantages and disadvantages as the product produced by the casting process; and the rim part is spin out, so the airtightness is better. Casting rotary products can theoretically reduce weight, but the actual application of the effect is not obvious.
5. Conventional forging and forging is one of the earlier forming processes for aluminum wheels. Forged aluminum wheels have the advantages of high strength, good corrosion resistance, accurate dimensions, and small processing volume. In general, the weight of the forged aluminum hub is only equivalent to 1/2 or less of the same size steel wheel. The flow direction of the grain of the forged aluminum hub is consistent with the direction of the force, and the strength, toughness and fatigue strength of the forged aluminum hub are significantly better than those of the cast aluminum hub. At the same time, the performance is very reproducible and almost every hub has the same mechanical properties. The typical elongation of a forged aluminum hub is 12% to 17%, so it can absorb road vibration and stress. Casting hubs usually have a very strong ability to withstand compression, but they are far less able to withstand impact, shear and tensile loads than forged aluminum wheels. Forged wheels have a higher strength to weight ratio. In addition, the surface of the forged aluminum hub has no air holes, so it has a very good surface treatment capability, which not only guarantees uniform and consistent coating, but also has a solid combination and good color. The major disadvantage of forged aluminum wheels is the large number of production processes and the production costs are much higher than that of the cast.
6, casting forging method It is the casting used as a blank for the forging process, plastic processing methods. Because forging is used as a part of the final forming process, it can eliminate casting defects, improve the structure of the product, greatly improve the mechanical properties of the product than castings, and at the same time give full play to the advantage of the casting process in forming complex parts, so that The forging process of products with complex shapes is reduced, material utilization is greatly increased, and production costs are reduced. The production of aluminum hubs using cast forging technology can fully meet the mechanical properties of forgings, but the production cost can be reduced by 30% compared with that of ordinary forged parts. At present, since the process was successfully applied to mass production in September 1996, it has been adopted by many Japanese companies and has a good economic effect. At present, only a handful of enterprises in the mainland (mainly in the Liuhe system in Taiwan) use this technology, and their equipment and technology come from Bulgaria.
7. Semi-solid die forging process The so-called semi-solid die forging is a process in which a semi-solid billet is heated to a semi-solid state having a liquid volume of about 50% or so, and then a forging is performed to obtain a desired near-sized finished part. A new process between solid and liquid forming.
The advantages of semi-solid die forging: less shrinkage of the parts in the mold, easy near-end forming, reduced mechanical processing; semi-solid die forgings smooth surface, dense internal structure, fine grain, higher mechanical properties than die casting and extrusion Castings; forming is not easy to gas, macro pores and micro porosity are much less than in conventional castings; the forming temperature is low and the tool life is long.
In the past 10 years, semi-solid forming technology has been widely used abroad, and has gradually become a new area that all advanced industrial countries are competing to develop. It is called by the experts and scholars a new generation of emerging metal forming technology in the 21st century. It is expected that in a relatively long period of time, the main market for semi-solid forming will be the automotive industry, and the more successful and widely used automotive aluminum alloy parts will be applied. Several semi-solid aluminum alloy die forging plants have been established in the United States. The United States' AEMP (Alumax Engineredmetal Process) company and Superior Industries have established a global semi-solid die forged aluminum alloy automobile hub factory in Arkansas in 1992. Using semi-solid die forging instead of low-pressure casting to produce ZL101 aluminum wheel hubs can not only reduce the machining volume and increase the productivity, but also improve the mechanical performance and reduce the quality.