Fast technology that adds up

Additive advocate and CEO of Harlow-FasTech, Alan Pearce, discusses with Ed Hill his company’s development and investment in metal additive technology.

Although in its early days in manufacturing generally, additive manufacturing (AM) has been keenly employed by the aerospace industry where its benefits of potentially lower cost production, design flexibility and rapid prototyping offer significant advantages over some traditional subtractive metal cutting processes.

One company that has already made significant advances in AM – or 3D printing as it’s often labelled – is FasTech, part of the Harlow Group of companies. Its CEO, Alan Pearce, was so convinced of the potential advantages of the technology he set up a new US based company dedicated to this disruptive manufacturing technology.

“My main experience has been machining aerospace materials such as titanium alloys, Inconel’s and other difficult to machine alloys,” he begins. “All have difficulties when it comes to mass material removal using a block of metal. Forgings and castings are possible alternatives but they can have very long lead-times and variable machineability that can cause costly, catastrophic tool failure and scrapped parts, alongside metal inclusions that can all make productivity and the final component quality challenging. With these problems in mind and the demand for an improved buy to fly ratio, I could see there was potential for near net shape printing technologies.”

Going to the wire

Initially, Pearce investigated various powder-based additive technologies such as selective laser melting (SLM) for larger components, but it soon became clear these would just take too long and not be economical to make bigger parts.

“I then discovered wire arc additive manufacturing (WAAM) a direct energy deposition technology,” he says. “Although I was first wary of the process – which is actually based on arc welding methods that were first developed incredibly in the late part of the 19th century – I soon found my concerns were put aside when we made test parts and then machined them in comparison to cast titanium processes.”

“It resulted in lead-time, cost of material and machining savings, so we decided to take a huge leap of faith and invest over £1.5 million in capital additive technology, even though we didn’t have an active potential customer.”

This was when the Harlow-FasTech division of the Harlow Group was set up in the US, offering both additive and machining services to customers, along with rapid delivery. The plant was set-up in the already high-tech and aerospace manufacturing-friendly location of Danville, Virginia and included investment in a Gefertec WAAM machine.

“I’d already had experience setting up a manufacturing plant there due to forward-thinking aerospace companies, such as Rolls-Royce and HondaJet moving to the region,” Pearce continues. “As well as offering attractive grants and a world-class talent pool of trained manufacturing engineers in the area, the US has a quick-to-try culture, and a customer base that we had identified as hungry for savings.”

Making a play for UK R&D

However, the Harlow Group still has strong connections with the UK and this is why it was keen to get involved in the Aerospace Technology Institute’s DRAMA programme headed by the Manufacturing Technology Centre (MTC) aimed at promoting additive technology in the UK aerospace supply chain.

“Our background with the UK-based Harlow Group and the manufacturing of copper and aluminium busbars for aero power systems led me to believe these types of parts, now also used widely in the electric car manufacturing industry, could be 3D printed rather than using typical fabrication and machining techniques. We met with the DRAMA team and they were soon able to offer grant funding with the MTC to create a project to investigate the feasibility of printing such parts.

“In principal, we discovered we could reduce the amount of time and number of operations from typically 12 to just 3, reducing lead-times from months to weeks and costs by as much as 30%.”

So what does Pearce think are the prospects for additive manufacturing in aerospace?

“When you consider that BAE Systems has just confirmed over 400 components for the new Tempest fighter aircraft will be additively manufactured, it’s clear there is an exponential growth market for manufacturers. Another good example is Airbus who have created their own internal WAAM approved manufacturing standard, AIMS03-29-001 that suppliers like FasTech can follow.”

There may still be hurdles, such as certification requirements, safety and traceability standards for additive processes to address for aerospace applications, but Pearce is sure the benefits mean these are worth overcoming because of the wide range of material, manufacturing and performance benefits it brings.

“Many companies are considering the advantages of components made by processes, such as WAAM. With WAAM, by redesign or simple tweaking, you can even create a hybrid material composition or matrix layered components that will easily achieve safety factor levels and be highly cost and lead-time attractive.”

He also believes that the major benefits from metal 3D printing come with the flexibility of newly designed parts that can fully utilise its potential as opposed to like-for-like replacement.

“If you can redesign, you should. For example, we can produce parts with multilayers of material with our technology. This could include titanium on Inconel or stainless steel with layers of heat resistant alloys such at Hastelloy. The choices we hope to develop are endless. With a completely new design, lighter, potentially better and more cost-effective parts can be made. With the flexibility of a new design, you can remove so much of the waste material; this is one of the biggest savings.”

At a time when the demand for ever greener and more sustainable flying solutions is being necessitated not only by OEMs but also legislation, additive processes could have a significant role in enabling this transformation, not just for aircraft but also the aerospace manufacturing industry.

“These technologies will lighten aircraft as well as reducing the buy-to-fly ratio. This in turn will reduce fuel costs. Furthermore, manufacturing will take less time and less power to make parts. Reduced machining could mean major electricity savings and therefore a better climate for all of us.”

The way forward

Pearce is adamant that metal AM will play a significant role in future aerospace part development and manufacturing. However, in the near future at least, there is still a significant role for both additive and traditional subtractive metal cutting methods to play a part to achieve the demanding tolerances and surface finishes required.

This is what Pearce terms as FasTech’s ‘Grow and Go’ process which involves parts being built layer-by-layer using WAAM and then milled for completion.

“There’s no doubt hybrid machines like 5-axis milling machines in the 1990s will become standard,” he predicts. “Both hybrid printing and machining technologies combined will become the norm and our own ‘Grow and Go’ manufacturing approach will just be part of everyday manufacturing.”

And he’s keen to point out that the currently struggling aerospace industry can’t afford to delay when it comes to the wider adoption of metal additive technology.

“I believe further investment should be considered to fast-track the huge benefits we’ve seen,” Pearce concludes. “Big savings can be made by printing aerospace parts. OEMs partnering with Tier 1 suppliers to advance it is critical. Considering the current economic climate in the aero industry, the huge cost savings must be considered now and in the near future. We are certainly ready!”

www.harlowgroup.co.uk/fastech