The aluminium alloys developed by Hydro – they were two years in the making – are considered advanced alloys for superplastic forming. They boast higher elongation or forming properties, achieve higher post- forming strength and enable lower cycle times than today’s alternatives. The three are:

• Next-generation 5083 alloy
• New 5456 alloy
• New 7020 alloy

Automotive OEMs are interested in superplastic forming because the process enables aluminium manufacturers to produce thin-walled aluminium sheet components. It is a cost-effective process that can stretch the sheet at least 200 percent above its original size. Large parts can be formed out of one sheet and thereby replace more complex constructions consisting of a high number of small parts.

Other advantages include part consolidation and low forming stresses.

“Automakers are developing increasingly advanced components, and this drives the use of superplastic forming. We worked with some of them, as well as several tier suppliers, in developing our new alloys,” says Jonas Bjuhr, head of strategy, R&D and innovation for Hydro’s Rolled Products business area.

High interest in automotive industry

The aerospace segment has been utilizing superplastic forming for specialty products for more than 25 years, and the process is also being used to manufacture aluminium sheet components for buses and railways.

In automotive, the process offers carmakers the ability to lightweight their vehicles with aluminium rather than more exotic materials such as carbon fiber and composites.

Bentley as is using superplastic-formed aluminium sheet for the door/side panel of its new grand tourer, the Continental GT.

“With our new alloys, we can now offer the right material for components that the automakers need,” says Reinhard Pritzlaff, technical specialist for Hydro’s business area Rolled Products.