The UK is leading the world in a game-changing new manufacturing technique that has the potential to usher in a new industrial revolution, with aerospace and other hi-tech sectors blazing the way. TIM ROBINSON reports from EADS Innovation Works in Filton, Bristol.
This is a full article published in Aerospace International: July 2010
Imagine entering an empty factory space with a gantry inside and an iPad workstation. Imagine touching a button on this iPad marked ‘grow wing’. Imagine coming back in 12 hours and finding a fully sized wing, complete with internal fuel tanks, flaps and other moving parts all ready for installation. Though this vision seems like science fiction or a Star Trek-style ‘replicator’ this concept is not as far-fetched as it looks, thanks to breakthrough work in additive layer manufacturing (ALM) now being carried out in the UK.
The advantages of ALM do not stop and end with time saved, which may be up to one quarter or one-eighth of the usual time. ALM promises stronger, lighter and cheaper parts which use less energy to make and require up to 26 times less raw material dug up out of the ground to make the finished part.
Rapid prototyping breaks out of the lab
So what is ALM? The concept behind it is not new and has been previously known as ‘rapid prototyping’ or ‘3D printing’ to provide fast physical models directly from a CAD/CAM ‘virtual’ computer design. Essentially how it works is the computer, much as a MRI scanner takes ‘slices’ of a patient, breaks down a 3D model into 2D layers. In an ALM machine a laser or electron beam then scans this layer into the powdered material, whether it be plastics, composites or now metals, burning the part into existence layer by layer, with a central ‘table’ dropping to expose the next ‘slice’ and fresh powder put in position. After the part is complete, the residual powder can be blasted off and used again. In this way ALM uses 90% less raw material than traditional methods, where waste can be up to 95% to make a finished machined component.
Using this method all sorts of shapes can be created, with internal spaces, tubes, ducts and moving parts. Even a flexible component such as a ball of chainmail can be created, which once removed, flattens out.
However, up until recently it has always been thought of as a niche capability — a ‘party trick’ useful for industrial designers but not suitable for larger hi-tech high-value components that demand extreme precision such as aerospace. The size of the machine, too, has limited the components to those which can fit in the ‘box’ — but that may just be about to change…
EADS Innovation Works
But thinking ‘out of the box’ is the mission of EADS Innovation Works in Filton, Bristol, which is now researching this technology and one of the leading centres in the UK for ALM, under its Centre for Additive Layer Manufacturing (CALM). Headed by Dan Johns, a veteran with experience in engine turbofan blades and motorsport, it is a hothouse of creatively thinking engineers and specialists who, in Dan’s words, ‘tend to navigate themselves here’, and include the UK table-tennis champion, a sculptor and a DJ. Indeed, the relaxed informal atmosphere brings to mind Google rather than a leading aerospace company. The people here implicitly believe they are creating the future — a cleaner, greener, more efficient way of manufacturing.
The Google reference is also true in another respect — as Johns believes this disruptive technology may one day invade the home — rather than ordering something from a factory, each house may have a home ‘replicator’ a truly profound change to society.
But nearer to the present is equally exciting. The much abused management phrase ‘thinking out of the box’ is literally true in this case, as Innovation Works’ researchers believe they are on the cusp of industrialising the technology with an ALM laser-deposition ‘nozzle’ that, like an inkjet printer head, could be mounted outside the traditional box. This concept, first developed by the NRC (National Research Council) of Canada, is now being refined by Innovation Works with the intention that gantries or jigs, with multiple nozzles and motion control, could now produce larger, more complex parts. Under CALM’s technology roadmap, the plan is to ‘grow’ a 38m leading edge wing spar demonstrator — to show that larger structures are possible and drive innovation.
Current ALM applications
But Innovation Works is also using its existing capabilities in ALM to design, optimise and create parts for a number of hi-tech industries. Indeed, it has an innovative approach to IP sharing and rather than hoarding knowledge — is determined to get the message out by picking niche problems and solving them with ALM. Says Johns: “We are looking at the long term. For example, it’s taken us 50 years to get where we are with composites, so we need to get going with ALM.”
Probably the key project that ‘put them on the map’ according to Johns was a rush requirement to develop a cooling duct for the Airbus A380 certification. Told by contractors that it would take 12 months to make, Johns and his ALM team did it in three months, saving time, money and high-level embarrassment.
Since then they have solved other tricky problems in engineering. The Red Bull Air Race aircraft, for example, all now use an air intake grill that, while being lighter, also increases power to the engine by 10% , by carefully optimised aerodynamic profiling. A satellite wave channel guide component for Astrium, usually costing £15,000, now can be produced for ‘a fraction of the cost’ using traditional methods.
Some idea of the aerospace efficiencies are that airlines could save some $300bn in the next 20 years thanks to ALM. CALM identified some 1,000 parts of Airbus products that could be built using ALM, and using Airbus’s global market forecast for 25,000 new aircraft, it estimates that ALM parts would save some 3,000 tonnes in weight — on the assumption that 1kg reduces fuel consumption by $100,000.
It is not just in aerospace where CALM is spreading the ALM gospel. The Force India F1 team uses components made through ALM. An EADS-sponsored sailing team has adopted an ALM mast socket. CALM is also involved with the Bloodhound supersonic car project, where driver Andy Green will design his own personalised steering wheel using ALM.
Finally, in advanced medicine (like aerospace and motorsport another area where the UK is leading the world), too, there are applications such as joints, hearing aids and titanium skull patches for patients that can be custom made to fit holes exactly — drastically improving survival rates.
Bio-mimicry and Hyper joints
Even more impressive is that the $300bn in savings noted above are only for existing aircraft when ALM replaces a component like-for-like. When second generation ALM components become available and aircraft are designed from the outset for ALM, then really amazing advances appear. Take a stainless steel A380 landing gear part. Engineered in ALM it is cheaper and faster to produce. However, if it is ALM ‘topology optimised’, than great chunks of metal can be taken out, making the piece 50% lighter while keeping the same strength and physical dimensions. The result looks something organic and natural, like a bird’s bone. This bio-mimicry can be taken even further because, as Johns points out, bones are hollow. With ALM, components can be created with hollow interiors resembling honeycombs, lattice work, or organic-like geometric shapes, drastically reducing the weight of the component. It is difficult to estimate how much saving in weight this might bring but Johns says a typical spar could be, with an optimised ALM design and this hollow bone structure, some 70-80% lighter.
As ALM develops then, expect to see bio-mimicry become more visible and into the design of the outside shape of the aircraft, as designers exploit nature to create components, and even perhaps entire aircraft, based on insects and birds.
In another ALM development, Innovation Works is close to solving the tricky issue of metal-to-composite bonds with a technology it calls ‘Hyper joints’. This uses a flat surface of hooked pins to ‘grip’ the composite material tightly, much like a carpet gripper - making the connection some three times stronger than a conventional solution. The composite and metal part is ‘grown’ as a single component, creating a link that is immensely strong. Furthermore it is possible to incorporate longer pins or angle them to take specific loads in certain directions — making the joint even stronger. Hyper joints would also be useful instead of traditional fasteners in fuel tanks, making leaks impossible.
The geeks shall inherit the Earth
Other applications are being thought up by Dan Johns and his team of polymath Google-geeks almost, it seems, on a daily basis. Using ALM, worn turbine blades, for example, could be re-lifed, by adding material to the tips. The MRO sector, thus would be a natural fit for ALM. The nozzle technology which takes ALM out of the lab, could also be used to repair composite materials. An airliner damaged by ‘ramp rash’ could be repaired in the field. ALM could also be used to keep historic aircraft flying, including ones with no original drawings, by scanning the physical part needed, inputting it into the ALM CAD/CAM computer, which would then ‘reverse engineer’ the part to provide a perfect carbon copy.
In UAVs, too, the need for rapid spiral development, where composite components can be quickly produced in small batches, then the next model upgraded and delivered to the warfighter, is an ideal fit for ALM, and the Innovation Works is working on an unnamed UAV project.
There are also applications in full-size stress testing. Innovation Works has already built a full-size replica landing gear out of resin to pose the question — will a cheap, quickly-made physical model provide the same sort of results as the real thing? The answer is yes, and this technique bridges the gap between virtual CAD/CAM engineering and expensive full size demonstrators.
ALM may also have a part to play in composite structures with embedded electrics, sensors, or even ‘self-repairing’ composites. This concept would see a composite component embedded with another material that reacts when exposed to air. Should the aircraft suffer battle damage, for example, the composite would ‘bleed’ and the ‘wound’ solidify. The part would be repaired enough to get the aircraft home.
Finally — there is the promise of engineering on the nano and atomic scale — effectively creating materials and then components with unique properties. During the tour of CALM, Johns demonstrated a plastic model of a flexible cube that was a scale model of a possible nano material. When compressed on one axis, it compressed itself on all axes thanks to its geometric structure. According to Johns, this sort of nano material could be the replacement for Kevlar as body armour.
At the atomic level, the idea of using atoms to create material directly is the stuff of Star Trek’s ‘replicators’. It is early days yet but the seeds are being sown here at CALM.
A new green manufacturing industry
Another advantage to ALM is its green credentials. It uses less raw materials and less energy to ‘grow’ components than traditional methods. With sustainability a major issue and the world facing resource shortages in the future, ALM may become one of the saviours that allows us to continue our hi-tech industrialised lifestyles. In fact, Innovation Works employs an environment engineer to try and pick holes in the process and expose any problems. So far he has not succeeded. The Innovation Works facility at Filton includes CALM which is a reclaimed building just across from the original Concorde wind tunnels. Here three ALM machines are based but, because of the clean, quiet environment Johns intends to develop this further as a model ‘factory of the future’ with office space above the quiet ‘factory floor’. He envisages that ALM factories in the future will be clean, green and lean, with possibly wind — turbines on the roof to provide electricity — a truly post-industrial revolution.
So what are the challenges?
So far, so good — and if only a fraction of ALM’s potential above is realised then it destined to be a game-changer. But what are the obstacles? One issue is that the CAD/CAM software is yet to catch up with the capabilities of ALM. Designed for rigid, solid components, the new possibilities that ALM gives means that it currently requires a lot of tweaking and modification to interpret it into a readable format for the production machines.
This leads into a second point that if, as predicted, ALM does take off in a big way, there needs to be an ALM qualified workforce in the future. Innovation Works is aware of this and partnering with academic institutions but it is clear that awareness of the potential career opportunities in ALM is fairly low at the moment.
A third point is the supply chain. Already under pressure from the OEMs to cut costs, time and battered by the recession, the last thing they need is someone saying that their production method is obsolete and they need to invest in new machines and capabilities. It has taken composites, for example, 50 years to make their way from niche products, to defence applications, to the wings of commercial airliners. So it will take time to convert the supply chain to this new method of manufacturing.
Finally, there is outside competition. The UK, says Johns, is some “three to five” years ahead of the rest of the world in this technology. However, as before, in jet airliners, these early leads can easily be thrown away once the competition grasps the almost unlimited potential of ALM.
Conclusion
In summary, engineers at EADS Innovation Works in Filton, (along with others in the UK, such as at Loughborough University) are on the cusp of unleashing an industrial revolution that may be as profound as the first one that propelled the British Empire to the forefront in the past. Clean, green and with the potential to save aircraft manufacturers time and money, and shave weight off aircraft, ALM looks to be too good to be true. But what is certain is the first countries and companies to exploit this will lead the way in the new post-industrial manufacturing landscape of tomorrow. And, uniquely, this method for high-value parts fits exactly the UK’s national excellence in aerospace, medicine and motor racing.
The UK, having been the country that began the industrial revolution, now could have a second chance to kick-start another industrial revolution in ultra-green, ultra-fast and ultra-lean manufacturing with aerospace blazing a trail for the rest to follow. The immense potential of ALM is simply too big to ignore.
This is a full article published in Aerospace International: July 2010. As a member, you recieve two new Royal Aeronautical Society publications each month - find out more about membership.
