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For the modified wheel hub, the friend of the performance fan may be scorned, because in most cases, the modification of the large-sized wheel, in addition to slower acceleration, poorer comfort, greater noise, fuel consumption is also rising, and it is becoming more and more slow. Case. But must this be the case? Let's let Netease use the test data to talk about the performance of the first forged magnesium alloy wheel in China.

First of all, for the first-time conversion enthusiasts, we need to mention why the modification of large-size wheels will affect acceleration, comfort, noise and fuel consumption. First of all, the increase in the size of the hub will inevitably increase the weight, although for the whole vehicle, it is not a matter of reducing a few kilograms, but for the hub, this is the power output source. For example, if you let you walk with weight, are you willing to tie the sandbag to your back? Still tied to your feet? Obviously, every weight on the hub is far more important than the weight of the car.

In addition, the weight of the hub will greatly affect the output of the power, and will greatly affect the driving comfort. On the one hand, a larger wheel hub will inevitably increase the width of the tire, and the larger friction area of the tire will inevitably increase the resistance and noise. In addition, in terms of shock absorption performance, since the hub is connected to the suspension damping system, the weight of the hub also affects the shock absorption performance of the suspension. This is why trucks that are fully loaded are often smaller and more comfortable than empty trucks.

But will the modified wheel hub be heavier and heavier? It is necessary to briefly introduce the types and characteristics of the hub.

The current mainstream wheel hubs on the market can be divided into steel wheels and alloy wheels according to the material, but in special fields, such as F1 racing, rally racing and Porsche 918Spyder, Pagani wind son Cinque and other super sports cars, there are also some carbons. High-end wheels made of brazing, titanium alloys and wrought magnesium alloys.

Steel wheel hub:

Advantages: simple manufacturing process, relatively low cost, and strong resistance to metal fatigue

Disadvantages: ugly appearance, heavy weight, large inertia resistance, poor heat dissipation, and easy to rust

Aluminum alloy wheels:

Advantages: light weight, low inertial resistance, beautiful appearance, reducing tire rolling resistance, thus reducing fuel consumption

Disadvantages: using casting process, the price is cheap, but it is difficult to ensure uniform density and moderate weight; forging process, the weight is relatively light, but the price is slightly expensive

Carbon brazing: The characteristic is that there is no shelf life! No material fatigue! Will not be corroded! The same intensity is the lightest! . The 2013 K?nigssee Agera is equipped with the world's first hollow, one-piece, ultra-lightweight carbon fiber hub. Although there are various advantages, because of the anisotropy of the carbon brazing itself (it is difficult to maintain a uniform density of the hub), the processing process is complicated and it is difficult to mass-produce. Germany's wheel manufacturing expert WHEELSANDMORE, the recently launched "Megalight-Forged-Series" two-piece wheel, only the outer ring is made of carbon fiber, the inner hub is a lightweight alloy, it has been lighter than the same size wheel. 40% or so; of course, the price is also considerable. Take 20-inch as an example, a group of wheels costs 20,000 euros, about 218,600 yuan!

Titanium alloy: It is mainly used to make aircraft engine compressor parts, followed by structural parts of rockets, missiles and high-speed aircraft. It has the characteristics of high strength, good corrosion resistance and high heat resistance. The advantage is that the working temperature of titanium alloy can reach 500 °C, and the aluminum alloy is below 200 °C. And working in humid atmospheres and seawater media, its corrosion resistance is much better than stainless steel. However, the disadvantages are also obvious. The process performance of the titanium alloy is poor, and the cutting process is difficult. In the hot working, impurities such as hydrogen, nitrogen, nitrogen and the like are easily absorbed. There is also poor wear resistance and complicated production processes. This property forces the titanium alloy to be different from conventional conventional refining, melting and casting techniques, and often causes damage to the mold; as a result, the price of the titanium alloy becomes very expensive.

Forged magnesium wheels: Metal materials that have received extensive attention in the automotive and electronics fields in recent years. Due to its light weight (specific gravity 1.74 g/cm3) and good mechanical properties, it has been used in batches in the field of vehicles and electronics. From Corvette's engine mounts to Cadillac's trunk inner panels, the lightweighting effect is also very significant, and the cost is about 10% higher than the traditional lightweight material aluminum alloy.

The magnesium-aluminum alloy, which seems to strike a balance between cost and weight, is also very disadvantageous. Because of its high chemical reactivity, it is corroded in acidic, neutral and weakly alkaline solutions. In the past, when everyone was in the middle school chemistry class, they saw that pure magnesium can burn in the air, so there may be some concerns about magnesium alloy. In fact, magnesium is difficult to burn after passing through the alloy, but it is easy to oxidize. Due to the easy oxidation characteristics, the surface of magnesium alloy parts is usually coated, and the processing is also carried out under closed conditions plus inert gas protection.

In addition, in the application of the hub, the magnesium alloy is further improved after the forging, and the special coating protection can ensure the use of more than 5 years. Even if the coating is smashed, the metal is exposed, and only the riders who are often used in wet and acidic environments need to repaint the paint as soon as possible (from January to March). If used in a dry environment, it is determined by the peeling of the coating around the wound.