British engineers at EADS Innovation Works have been using some of the company's most exotic equipment to build a bicycle, but they will not be accused of diverting valuable resources to a personal hobby. The "Airbike" will not be ridden in the Tour de France any time soon, but as a vehicle for demonstrating the game-changing potential of additive layer manufacturing (ALM) it was a huge triumph for the team at Filton.
EADS's ALM process, developed from the rapid prototyping technology sometimes described as 3-D printing, promises to replace forged or cast parts with components built from resin or metallic powder that is sintered into thousands of layers by laser, with no special tooling. EADS UK chief executive Robin Southwell says the Airbike, built from nylon-resin powder, hints at "a paradigm shift".
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© EADS Innovation WorksOnly the tyres and drive belt did not come out of the ALM machine |
He may not be exaggerating. According to Innovation Work's ALM team leader Jonathan Meyers, mastery of this technology could bring several important weight, cost, design and speed advantages to EADS. Traditional forged or cast and machined parts feature large volumes of material that is not load-bearing because it is either too difficult or too costly to machine it away. As much as 90% of the material in a forging is machined away to reach a final shape compared with as little as 5% with ALM.
That key difference is becoming increasingly attractive, says Meyers, as more and more aircraft components are made from titanium alloys to save weight and to avoid galvanic corrosion when in contact with composites. Traditionally made titanium parts get more expensive as they get lighter because the material is expensive and costly to machine, but ALM parts are cheaper as they get lighter, in what Meyers calls "a virtuous circle" of high performance.
Innovation Works has already demonstrated the potential of metallic ALM parts, with some "significant structural parts" having featured on Force India's 2010 Formula 1 cars. Meyers reckons EADS could be as little as three to five years from using ALM parts on civil airliners. EADS Astrium hopes to fly a spacecraft this year featuring some ALM parts.
In 10 years, he says, structural components up to about 5m (16.4ft) in size could go to ALM.
Another ALM advantage is its speed in moving from design to production. The Airbike was realised in just six weeks.
Cycle time in production is relatively slow, so for now production runs measured in 1,000s of units are not candidates for ALM, but Innovation Works research is promising, says Meyers.
Another key to successful ALM will be to teach engineers to think creatively about the use of what Meyers calls a "disruptive technology". Working with university students, he notes, is a key to building a generation of "ALM-savvy engineers".
Source: Flight International
