o determine the difference between alloy and aluminum wheels is a bit difficult since aluminum in its pure “aluminum only” form is not very strong. A wheel frame needs to withstand a lot of pressure, weight, and environmental conditions. Pure aluminum could not withstand the weight of a car; it is a light metal, and when combined with another metal, it creates a strong aluminum alloy. The quick is answer is that there is no difference because many “aluminum alloys” are just called aluminum.
With that being said, there are several different methods of making a metal wheel that impacts its strength and purchase cost. The most costly and strongest wheels are produced from hot forging. The molten metal is poured into a hard cast and cools; the superior strength comes from the solid grain structure generated from forging.
A less expensive method to make a metal wheel is called billet machining. The shape is essentially cut out or machined from of a larger section of material. The grain is not as consistent as with forging; rolling a wheel refers to using forging to make the rim while other methods are used for the spokes and other parts.
The least expensive methods for making metal wheels involve what is called casting. The molten metal is poured into a mold. The force of gravity will pull the molten metal into all the spaces in the mold. Using gravity alone can leave pockets of air which reduces strength. Casting can also be done with the help of a vacuum - the suction will pull out air pockets and compress the metal for a stronger wheel. With metal wheel frames, know that “alloy” and “aluminum” both stand for a form of aluminum alloy; the difference is in the formation only.
If you have questions about aluminum wheel manufacturing technology, contact the experts at Superior Industries International today! We are a Michigan aluminum wheel manufacturer and one of the largest OEM suppliers for aluminum wheels in the automotive industry.