A New Wheel Design for Reducing Weight
Reducing weight is one of the most important challenges in the automotive industry. A wheel design which enables to reduce weight from 13.5 kg to 10 kg is presented. This achievement is possible thanks to the use of a wide variety of technical processes. The disc is manufactured by CobapressTM, a casting/forging process which combines the advantages of a high design freedom, good mechanical properties and the absence of porosities. The alloy used is an A356 aluminum alloy modified with strontium. The rim is made of an AA6082 aluminum alloy which is extruded and flow-formed with a thickness from 3.3 down to 2.2 mm. Finally, the FSW (Friction Stir Welding) allows us to weld the two parts with a cavity to minimize the weight. With this technique the welding of the two different alloys is possible with good mechanical properties, the fracture happens outside of the weld during tensile tests. The final wheels passed bending and radial fatigue tests as well as radial impact tests with success.