“We want to be ready for the next generation of aircraft.”
A two-hour tour of GKN Aerospace’s (GKNA) Global Technology Centre (GTC) in Bristol, UK can be summed up in those eleven words. Tim Hope, GKNA’s Chief Technologist, Metallics, utters them as we grab a coffee nearby a designated meeting spot. Mine’s a latte, Tim’s an americano, and Brad Hughes – Lead Technologist, Additive Manufacturing – goes without.
The GTC was funded by a 17 million GBP commitment from GKNA and a 15 million GBP commitment from the UK Government, with then Prime Minister Boris Johnson opening the site in October 2021. It has been designed to facilitate greater collaboration between GKNA’s internal departments and its external customer base and partners. Today, there are several customers onsite, while multiple groups of GKNA staff break out into collaborative workspaces that include closed-off meeting rooms, presentation areas and more relaxed seating arrangements. Everybody in the building is undertaking activity-based work, with no fixed desks and workers free to operate in whichever part of the building best suits their needs at the time. Metallographic art pieces adorn the walls, and each level of the building is named after a founding member of GKN: John Guest, Arthur Keen, and Joseph Henry Nettleford.
As we re-caffeinate, we’re towards the top of this multi-storey building, overlooking the car park below and discussing the move from one site in Filton to this one. The transition commenced during the COVID-19 pandemic as the facility was still being built, which meant the first movers were often required to don a hard hat and face mask while reinstalling and running manufacturing equipment – additive or otherwise. Unplugging, transiting and redeploying the additive machinery was, initially, a cause for concern for GKNA, who had never undertaken such a task. But when they set back up in their new home, they were pleased to not encounter any process instabilities.
That meant normal service resumed with great efficiency for the tier one supplier. In this capacity, GKNA is focused on serving its civil and defence customers with airframe and engine products. To do that, it has developed expertise across metals and composites, with its additive manufacturing capability falling within the former. Much of that additive capacity is split between a proprietary metal deposition technology and a fleet of off-the-rail metal powder bed fusion machines.
GKN Aerospace
GKN Aerospace's proprietary Laser Metal Deposition by wire (LMD-w) technology developed through the AIRLIFT research programme.
The adoption of additive manufacturing aligns with GKNA’s pursuit of a ‘more sustainable future of aerospace.’ With AM, the company sees value in being able to optimise both weight and cost for engine and structural components while also acknowledging the present challenge in guaranteeing repeatability for its blue-chip clients.
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“Fundamentally, we need to generate trust,” Hope says as he places his coffee cup back down on the table. “[For additive,] that repeatability, reproducibility creates trust in the process and trust in us that when we deliver a part, we need to deliver it on time to cost with zero defects. That takes a lot of focus and the role of AM from a metallic standpoint is that we are de-risking technology here, such that we know that we can provide trust.”
At ground level, we began with a quick run through a deck of slides, presented by Hope in a quiet spot that overlooks the shop floor. As Hope detailed during his presentation, the shop floor behind us is used to build air structures – that a build is ongoing is the reason we can only look down on the factory from afar today – and is home to an extensive additive manufacturing capacity. In an enclosed space, there are multiple Direct Metal Laser Sintering systems procured from EOS and Renishaw running diligently, while out of sight exists a Laser Metal Deposition by wire (LMD-w) technology developed through a research programme called AIRLIFT. The LMD-w capability is currently being used within the company’s engines business, with a view to also harnessing it for aerostructures products. It has the potential to print up to three metres in its maximum dimensions.
Though GKNA currently prints parts that fly using this equipment, the company is still in the process of validating the technology – against its own standards, that of its customers and that of the authorities. Certification of new processes like AM remains one of GKNA’s biggest challenges, and while in-process monitoring and simulation are helping to address that, it is said that open systems are also a big help. GKNA can therefore more often guarantee quality for its LMD-w process, but for powder bed, excellent relations with vendors are needed.
“All parts of the additive supply chain, if you’re in aerospace, need to be cognisant that at the top of the tree for getting parts flying is the aviation authority,” Hughes notes. “They describe the information that they need [and] my entire value chain needs to be able to provide that. That’s down to heat treatment, powder suppliers, machine suppliers, and so on. If you’ve got blank bits in there that you can’t see into, that is a challenge. The more open that can be, the more opportunity you’ve got to draw them down the garden path saying, ‘yes, we’ve got all that data.’”
GKN Aeropsace
Inside GKN Aerospace's Global Technology Centre in Filton, Bristol.
Hughes joined us in a sizeable workshop adjacent to the shop floor. At the back of the room is a row of desktop and benchtop 3D printing platforms – from left to right, we have a Designjet machine co-developed by Stratasys and HP way back when, an Ultimaker S5, a Formlabs Form 2 and a Markforged Mark Two. These machines – including the Designjet – are often called upon to produce jigs, fixtures and design aids, but GKNA was never going to stop at desktop platforms. After the Designjet, GKNA’s next 3D printing system in Bristol was an Arcam A2.
A few feet from this row of 3D printing systems sat two trays of parts printing on its LMD-w and DMLS technologies.
Among the printed parts GKNA showcased were tanks demonstrators and other components produced to near net shape with LMD-w, and certified bracketry components built with DMLS. Engine components are the target for its powder bed capacity, while the LMD-w technology is likely to cater for larger structures not applicable to DMLS. Confidence is growing within GKNA relative to 3D printing technology. The company is active in a range of standards working groups, recognises the strides made in recent years by the likes of NASA, ASTM and SAE in developing such standards, and maintains good relations with both commercial and academic entities. But in working to these standards, GKNA is confronted not only with ensuring the technology is repeatable but also the cost of generating the dynamic properties required for aerospace parts.
“There are just two challenges in AM for aerospace,” Hope reckons. “The productivity challenge and the certification challenge. Can you make the right part every day the same way, which is a massive technical challenge, and then can you make it cost-effectively compared to other processes? Once you’ve nailed those two hygiene factors, you get to the real win criteria of additive manufacturing. This stuff’s awesome in terms of what the future could be, but to make this stuff happen, we have to be able to get it to buy itself onto the aircraft. And that’s about trust with the regulators and the end users about the cost performance.”
“AM is now at the business end of the hype curve,” Hughes adds. “You see lots of fun stuff [but] we need to make this happen in a real way on real applications, that unlocks the fun stuff for the future, but it’s about 'can we get real business benefit in the short to medium term for the long-term payoff?' We can all see through topology optimisation, functional integration, all that good stuff, but confidence with customers, confidence with certification bodies, that’s where the business side of it is now. And that’s where our focus is.”
GKN Aerospace
Parts printed with GKN Aerospace's LMD-w technology.
As they work towards achieving that level of confidence in Bristol, the company felt a new, more modern home was required to align with its ambitions. GKNA welcomed workplace consultants into the business to assess how work was carried out at the old facility to implement better workspaces in the new one. And as we dart from one collaborative workspace to another, via workshops and shop floors, it is clear that GKNA is intent on remaining a leader in its field. And the key to that, Hope believes, is ensuring the business is sustainable.
“There aren’t that many aerospace OEMs, so everything that we do in AM is focused on building supplier trust,” he says. “If you understand the needs of our customer and you deliver what you said you were going to deliver when you said you were going to deliver it then you’re a long way to having a sustainable business. The innovation comes from the market demand, the business and the technical viability, and those three need to mix. But you’re only successful if you can do that repeatedly and in a way that’s in a spirit of trust.”
And just like that, meetings are drawing to a close, vehicles are departing the car park, and our coffee cups are empty. We are heading down the stairs ready to say our farewells when we spot at the far end of the foyer Hughes’ first ever 3D print from around 2014. Hughes explains that the request for this part was something that GKNA had never considered before – producing a set of acoustic liners on a DMLS printer. He received a set of dimensions for the components on a Thursday morning, modelled the part in CAD that evening, did the nesting with the process team on Friday and it was on his desk by Monday morning. It ended up being used in an engine test.
“That’s pretty special,” Hughes says. “The first time you see how quickly you can go from idea to concept, in metal as well, that was really powerful.”
It was. But today, Hope shrugs: “We wouldn’t even make a big deal about it anymore.”
GKNA's Brad Hughes will be speaking on Day Three of the TCT Conference @ Formnext in November. The full conference agenda can be found here and tickets can be purchased here.
