Alcoa Invests in Adaptable OE Wheel Forging Technology

Cleveland, Ohio-based wheel manufacturer, Alcoa believes it has solved the problem of how to launch multiple new wheel programmes quickly without repeat capital investment. The company says that it has refined a process that generates “an infinite variety of styles from a single forged tool” through variations in design, machining and finishing. Using this process, Alcoa believes it can produce products that are amongst the strongest, lightest wheels available, but with the structural integrity to meet the toughest fatigue requirements. In terms of finishing too, Alcoa’s patented Dura-Bright surface treatment technology allows a wheel to be further differentiated not only by design and structure but also appearance and performance.

The company explains that in the current market crisis, OEMs need to revitalise the appeal of their cars and prompt new car sales, but with minimal or no investment to help reduce costs. Adding new wheel programmes to a model range can often help improve the desirability of a car through cosmetic enhancements. Alcoa’s flexible manufacturing process can now offer car makers the opportunity to launch these new wheels quickly and at low cost.

The base forging blanks are produced from billets of 6061-T6 aluminium, using the same metallurgy as the wheels Alcoa produces for the Boeing 747. An optimised forged wheel can be half the weight of a typical cast alloy wheel of the same diameter due to their superior material properties. “We can vary the wheel style and finish options widely, within a given forging envelope, without changing the base forging, resulting in many different styles with a single forged tool investment” says David Yates, commercial manager for Alcoa Auto Wheels Europe. “We are now using this principle widely for OEM customers in Europe and USA. Chrysler, for example, adopted this for the SRT family; wheels for the various models look quite distinctive yet share the same tooling. GM launched a range of wheels for limited edition models quickly, from a single tool investment and they have been very successful.”

As well as styling freedom, forged wheels provide a fast-to-market, cost-effective weight reduction; in particular, the lightweight rim sections reduce the rotational inertia of the wheel which improves the fuel efficiency of the car and reduces CO2 emissions. Lower wheel mass also means less work for the suspension; tyres remain in better contact with the road surface as lighter wheel assemblies are easier to control when hitting bumps; particularly important when cornering. This translates into improved grip, traction and braking, better vehicle control and a smoother ride.

Manufacturing also benefits, becoming leaner; apart from commonality of tooling, Alcoa’s approach results in reduced inventory and offers shorter lead times since the final machining is able to draw from a common stock of forged blanks. The machining process is cost-effective, requiring only three-axis machines for most applications, though five-axis capability is used for exotic designs such as the Lamborghini SV.

“Prestige brands such as Ferrari and Lamborghini already use our products, as do higher volume customers such as Audi and Chrysler,” concludes Yates. “The volume of enquiries is increasing rapidly because stylists like the design freedom; engineers like the light weight and accountants like the control of tooling costs.”