Abstract: Lightweight can not only save energy, reduce emissions, but also improve the performance of heavy vehicles. In order to promote lightweight process of heavy duty automobile, the forming technology of the aluminum alloy wheel rim originally made in steel are studied. Investigation on influence of deformation temperature and deformation passes on microstructures and mechanical properties of 7A04 alloy, multiple deformations technology to achieve strength-toughness controlling is developed. The good comprehensive mechanical properties are achieved after 4 passes deformation at 480 ℃ for 7A04 alloy. The anti-extrusion from hollow billet to reduce the forming force is developed. The analytical results by slab method show that the forming force decreases enormously with the decrease of contact area and normal stress on the interface. The 20 inch one-piece aluminium alloy wheel rim is manufactured on 12.5 MN vertical hydraulic press. Over 55% structure weight loss can be achieved by replacing steel. The aluminum alloy wheels have been applied in heavy vehicles and provided a new method for reducing weight of equipments.

Key words: Aluminum alloy, Extrusion, Lightweight, Wheel rim, coatings, fatigue life, Ni60A, optimization, rolling contact fatigue, Weibull distribution