From a single cast
The production of alloy wheels has a long history behind it. Humankind mastered the technique of casting metals around 5,000 years ago. During the era of industrialization, cast iron became a key construction material that could even be used to build entire bridges.
At the end of the 19th century, aluminum gained significance for casting – and is the material that is used for modern alloy wheels. Standard parts for the automotive industry were already being manufactured out of aluminum around the year 1900.
Today, low-pressure die casting is also the proven method that RIAL uses to cast alloy wheels from a single pour. The liquid aluminum is pressed into the hollow space of the wheel rim casting mold from below using gas pressure. While it gradually cools, the pressure is maintained. This ensures that fresh molten metal continues to flow and compensates for the shrinking volume during cooling. The result is an even material thickness.
As the molten aluminum is introduced from below, the new wheel should solidify from the top to the bottom. The wheel designers take this specification into account, for example by ensuring favorable cross section transitions. After casting, depending on the material used, a further heat treatment helps make the alloy even stronger. All wheel blanks are x-rayed to ensure that there are no inclusions or cavities in the material.