We all know that the so-called high-end wheel hubs are very expensive. In fact, high-end cars are expensive. Take a car wheel as an example. The manufacturing process of high-end cars is completely different from that of ordinary cars. At present, the manufacturing process of aluminum alloy wheels on automobiles is mainly divided into two types: casting and forging. After everyone understands the difference between the two, you can understand why high-end models prefer to use forged wheels!

The casting process of the wheel hub: Let¡¯s talk about the casting process first. As everyone knows, most of the aluminum alloy wheels on the current models are all cast, but there are three different manufacturing processes for cast wheels, namely gravity casting, low pressure casting and spinning Casting.

Gravity casting:

A kind of china wheel manufacturer process that will be on the verge of extinction. It mainly fills the entire wheel mold with the weight of the melted liquid aluminum itself, and is formed after natural cooling. This kind of wheel has a higher yield and lower mold cost, but the disadvantages are also obvious¡ª ¡ªIt is difficult to control the flow time of the molten metal, because the slow flow of the molten metal will inevitably cause the temperature of the metal at the end farther from the casting port to be lower. At this time, the stable temperature control of the mold becomes very important, too high Or too low will affect the manufacturing quality of the hub; however, in order to prevent premature solidification, the temperature of the aluminum water needs to be increased, but it is easy to cause uneven molecular distribution and more sand holes. At this time, it is necessary to maintain the strength Pour more aluminum water, so the weight of the finished wheel hub of gravity casting will increase.

Low pressure casting:

Low-pressure casting is based on gravity casting. It uses low-pressure nitrogen to carry out the process of "accelerating the speed of filling the mold with liquid aluminum" on liquid aluminum. With fewer bubbles, the distribution is more uniform, and the metal structure is more compact. The performance is better. Although under the effect of low pressure, the density of the hub becomes higher, but the goal of lightening is only a few points away.

Spinning casting:

The spinning process, strictly speaking, is also a branch of "casting". The wheel hub produced by its process includes two different technologies: "spinning" and "casting". First, the disk surface shape and the rough rim blank are produced by the method of "low pressure casting". Before this step, it is the same as the general casting. The method is exactly the same. The rough embryo produced looks like a wheel with a shorter width, while the inner rim is thick and looks short and fat.

Next, the rough billet must be sent into a heating furnace and heated to a high temperature of about 400 degrees. Because it is not yet the melting point of the aluminum alloy, the aluminum alloy rough billet remains in a solid state, but is slightly softened to be processed. Temperature, and ¡°spinning¡± uses high-pressure rollers to pressurize and extend the side of the rough rim blank. In simple terms, the principle of ¡°spinning forming¡± is like a ¡°hand pull ceramic blank¡±. Applying pressure to elongate and thin the aluminum alloy billet. Due to the high pressure reshaping the aluminum alloy, the density of the aluminum alloy during processing can be increased, making the internal crystal structure of the aluminum alloy more compact. This is the same as "forging" The principle of high-pressure pressing and increasing metal density is the same. Since the metal material is stronger, the strength requirement can be met with a lighter and thinner rim body.

The forging process of the wheel hub: Let¡¯s talk about the forged wheel hub. The manufacturing process of the forged wheel hub is to first heat the aluminum block. After reaching a certain temperature, press it into a blank with a forging press and then spin the blank into a shape, which is equivalent to the strength of a cast wheel. Higher, and forged wheels are made of military-grade aluminum, which is lighter in weight. Forged wheels can also be subdivided into one-piece forging and multi-piece forging. One-piece forging means that the entire wheel is formed in one piece and is light in weight. The reliability is good, and the multi-piece end-to-end rim and the spoke type are separated. The advantage of this is that only the spokes can be replaced to have a new wheel style, but compared to the one-piece forging, the multi-piece forging will be heavier , The requirements for assembly are also compared.

To sum up

On the whole, because the production process of forged wheels is more precise, stronger, lighter, and several are very expensive, spin-casting wheels are more cost-effective than forged wheels, so there is no need to change the wheels. Pursue forging.