Cost-effective and environmentally friendly: The new lightweight aluminium is being formed by using creep forming in a package at 325°C.
The new high-strength alloy AlMgSc with magnesium and scandium is five percent lighter compared to standard aluminium and has at the same creep limit also an enhanced corrosion resistance. At the same time the production process with cutting, milling and surface treatment remains almost the same. Differing from standard aluminium 2024 the skins aren’t separately stretch-formed – instead they are 3D formed in a packet for two hours at a temperature of 325° Celsius.
Further development provides the heating with mats which only deliver direct heat to the underlying formed stack of sheets. Basis of this application was the development and production of a completely new 3D vacuuming tool system. This device features only half of its usual mass. The moulding has a honey-comb like grid structure with encasing and sealing panelling as well as thin and furthermore isolating shaped plates.
The successful use could also be verified for 2×2 m section demonstrators in a package. This way the heating time could be shortened from 2 to 1 hours under the compliance of the sufficiently exact temperature distribution – and that’s by only 5% of the oven energy! The result is an even ecological as well as an economical advancement.
For the rear section of the pressure cell of an airplane – the front end measuring 3 m spherical segment was joined from 2 parts using friction stir welding and transformed by creep forming.
Further sampling using heating mats are in packages and for original 10 x 2 Meter in size complex formed skins with hold-down clamps planned and are taking place at the technology center in Nordenham.
AlMgSc is a superior aluminium alloy which through proven innovative technology and clearly cheaper forming costs is compensating a significant part of the material costs, a specific implementation option for a clearly more lightweight metal plane.