With the passage of time, many advantages of aluminum alloy wheels have been recognized and accepted by more and more people, and the loading volume has also increased. Recently, some car friends asked why the price difference between forged aluminum alloy wheels and cast aluminum alloy wheels is so large. Both are aluminum alloy wheels. What is the difference between them?
Casting wheel technology is relatively simple, suitable for mass production and low cost
Casting is the most common process for producing aluminum wheels, and it is also relatively economical. The more common ones are gravity casting and low pressure casting. Gravity forging is to cast molten metal in a mold to form and harden, and then the cooled blank is subjected to precision machining, polishing, and painting on a lathe to obtain a finished product. Low-pressure casting is a relatively advanced casting process. The molten metal is sucked into the mold with vacuum suction. This is beneficial to control the temperature and eliminate impurities. There will be no pores in the casting and the density is uniform, and the strength is higher than that of low-pressure casting. But no matter what kind of casting, its technical process is relatively simple, suitable for mass production and beneficial to reduce costs.
Forged wheel technology is complex, high cost but very good performance
Forging is currently the most advanced production method under mass production of wheels. Forged wheels are used to repeatedly forge an aluminum ingot under a certain pressure with a large forging press to form a wheel blank. After forging, the blank is processed by spinning. The effect of this process is to stretch the width of the rim to reach the corresponding specifications. After spinning, the hub has been basically shaped, and then processed by machine tools, after polishing and painting. Get the finished wheel hub.
Because the forging technology is complex and the forging equipment is expensive, the cost of purchasing some large forging presses is tens of millions of yuan, so the cost of forging wheels is relatively high.
Metallographic analysis: Forged wheels perform very well
We can see that the cut surface of the forged wheel below is very lubricated, the metal molecules are placed tightly without roughness, while the metal molecular pendulum of the cast wheel is loosened, and the metal particles are larger and the cut surface has a strong sense of roughness.
The difference between forged wheels and cast wheels
Checking under a microscope, the metal molecular pendulum of the cast wheel hub on the right has looser particles, while the metal molecules of the forged aluminum alloy wheel hub on the left are placed very tightly. The tighter the metal molecules are placed, the higher the fatigue resistance of the wheel, and the stronger the impact resistance, the better the bearing capacity.
The appearance is difficult to distinguish, the weight is different
The appearance of some cast wheels imitates the characteristics of forging, so it is difficult for ordinary consumers to distinguish them, but the two are quite different in metal properties. The fatigue resistance, impact resistance, and strength of forged wheels are higher than those of cast wheels. There is not much difference in the heat dissipation function. However, cast wheels of qualified quality are generally about 20% heavier than forged wheels.
