Rio Tinto received the first order for its Revolution-Al™, a new high strength aluminum alloy developed to make lighter weight car wheels. The development of the new alloy was five years in the making, representing the company’s commitment to innovation. The project was carried out in cooperation with the company’s customers, who helped trial and test the new alloy.
“The current wheel alloy has been around for a long time and now we’re coming to the market with a new way of doing things,”said Jean-Francois Laplante, industrial product and investment director for Rio Tinto. “We were super excited when we saw the result.”
Alloy Development
The project was initiated when researchers at Arvida Research and Development Centre (ARDC) in Saguenay–Lac-Saint-Jean, Canada were presented with the challenge of developing a stronger alloy for die cast car wheels, which would enable vehicle manufacturers to cut fuel consumption, improve safety and handling, and meet strict industry standards.
“We wanted to offer automakers a new, innovative alloy that allowed them, through styling and design, to reduce the weight of the wheels, which is very important to improving fuel efficiency – because, in the end, people want to drive not just the safest but also the greenest and most innovative cars,” explained Jerome Fourmann, technical director for Rio Tinto.
Researchers at the ARDC considered the most commonly used aluminum alloys in the foundry industry — A356.2, which has good mechanical properties and is widely used is cast aluminum wheels), and 357.1, which is used for higher strength applications, such as suspension parts and aerospace. Both alloys provide medium- to high-strength properties with excellent fluidity and corrosion resistance.
The new Revolution-Al improved on A356.2 and even 357.1 by adjusting the chemical composition of current aluminum alloys (i.e., controlling inherent detrimental phases in the alloys), thus improving the final mechanical properties. Specific alloying additions were made to eliminate the β and π phase formation, which resulted in a better strength/ductility ratio. The team also considered the castability of the alloy and how to avoid foundry operational changes (i.e., no need for additional investments).
Following the initial research, industrial and OEM trials of the new alloy were performed using an optimized automotive wheel design. Due to the improved mechanical properties, the alloy is 15-20% stronger than the traditional A356.2. The increased strength, in turn, enables a 7% weight reduction that can help achieve better fuel efficiency or battery range in the vehicle. The lighter, stronger wheels also mean better performance and handling and reduced tire wear.
In addition to car wheels, Revolution-Al could be implemented for other important automotive parts, including chassis components (such as the suspension), brakes, etc.