Aerostructures and engine component supplier GKN Aerospace is working to perfect future production methods that would save weight and improve fuel economy on current and future generations of airliners.
The company sees new techniques such as additive manufacturing, better known as 3-D printing, and the use of microwaves to speed the production of composite components as disruptive technologies, which could radically influence the speed and cost at which components and spares could be made in the future.
One of the areas the company is exploring is the ability to mass-produce a low-cost laminar flow wing. The work, on behalf of the European Union’s Clean Sky II initiative, will see the wing take flight attached to the outboard wing of ansome time in 2015. In conjunction with , the companies are using a composite skin and a metal leading edge, while the internal ribs are also metallic, and could be produced using additive manufacturing, to reduce the reliance on forging and molding.
The company wants to achieve weight savings of around 5% relative to existing composite wings, while reducing overall cost by 25% but maintain a production rate of around 50 wings per month.
Additive manufacturing processes are an area in which the company has already built a large infrastructure, having opened four technology centers dedicated to the subject.
The company is experimenting producing smaller components using the powder-bed technique or larger ones using laser wire deposition.
Speaking in London in early May, GKN technology officer Rich Oldfield demonstrated a small bracket that had been produced wholly using the powder-bed technique. He said it was already flying on an undisclosed aircraft and that the company was hoping to achieve approvals for such items produced through this method during the next 12-18 months. Meanwhile, additive manufacturing is also being used on elements of the Intermediate Compressor Case (ICC) for theengine. While the case itself is molded and forged, elements on the outside edge of the case are added using additive manufacturing.
“With the powder-bed process you are limited to small parts, but with the laser wire capability you are able to build fairly large parts,” says Oldfield.
Additive engineering is able to reduce the manufacturing costs of components by 30% by eliminating the need to produce molds. Furthermore, fabrication time can be reduced from weeks to days or even hours, but Oldfield believes greater savings are going to be possible as designers change their philosophy and design components that are designed to be produced through additive manufacturing, rather than over-engineering them, as many components are produced today.
“At the moment we are simply producing components using additive manufacturing, using designs developed as if we were going to forge or mold them,” says Oldfield.
“If we think about making these parts with the additive manufacturing methods in mind, we may be able to reduce the weight of these components even further.”
Waste could also be significantly reduced. Although most companies like GKN recycle their waste metal, some techniques such as forging can waste 90% of the material. Additive manufacturing can cut this down to as little 10%, making better and more efficient use of expensive and sometimes rare materials.