Autodesk’s collaborative research & innovation team manager, Kelvin Hamilton explains why directed energy deposition (DED) must become a basic tool in the aerospace manufacturing toolbox.

In 2017, over 4.1 billion passengers were carried by the world’s airlines and 10.2 million people worked directly in the aviation industry worldwide. To meet the crucial climate targets that have been set, the industry must improve fleet efficiency. The manufacturing industry plays a crucial role in helping achieve these targets, finding ways to build complex and robust parts, faster, cheaper and with reduced weights. So, what can be done?

Additive manufacturing (AM) is increasingly being used to build complex parts, waste less material and reduce the weight of parts. There are several types of AM as defined by ASTM. The two most commonly used for producing metal components in the aerospace industry are powder-bed fusion (PBF) and directed energy deposition (DED). PBF is a powder-based AM practice where metal particles are fused together by the application of heat typically with a laser or an electron beam to build a complicated and customised part.

Due to the technology’s higher build/deposition rate, DED methods are typically used for manufacturing larger components that will subsequently be machined to achieve the final component’s shape. However, though DED has been around for a few decades, the processes (electron beam + wire, arc + wire, laser + wire, laser + powder) are not yet widespread in manufacturing.

With industry now reaching the limit of what current technologies can do, DED offers the opportunity to respond faster, produce more efficiently, and produce parts locally with greater flexibility than would have been possible by traditional manufacturing techniques. Indeed, components can be produced faster and in small batches, with less waste and with more customisation.

Under the BeAM spotlight

While AM technology is not fully entrenched in the manufacturing industry, there are companies championing its use. One such organisation is BeAM – a global leader in the DED technology (laser + powder), which makes AM machines for the aerospace, defence, and energy sectors. The company recently joined forces with AddUp, a leader in the design, production, and marketing of metal 3D printing machines and production lines. Together, they offer a comprehensive range of metal AM solutions, including, training, consulting, 3D printing systems and the making of parts for proof of concept (POC).

BeAM’s machines enable the additive manufacturing of highly-complex metal parts, principally in titanium, Inconel and stainless steel. Having perfected its innovative repair of critical parts process, it has registered its technology at the highest qualification level for the repair of aeronautical parts in turbines. However, it wanted to challenge traditional aerospace manufacturing processes further.

Every small improvement in aircraft design and build can have a large impact on fuel efficiency and ultimately the environment. Today’s aircraft use roughly 80% less fuel per passenger-mile than the first jets of the 1950s, a testimony to the tremendous impact of aerospace engineering and emerging technologies.

With the use of powerful CAM software, BeAM has been able to make complex parts that are closer to the finished size and shape, requiring a minimal amount of finishing processes such as machining. This was achieved primarily through expert control of the hardware, as well as a stable and robust process.

One example is BeAM’s manufacturing of a 5.2kg gas turbine engine exhaust nozzle, additively manufactured on the Magic 800 machine using Inconel 625 powder. The part was built to near net shape in nine hours, bringing with it the benefits of shorter lead-times, lower costs and less material wastage when compared to traditional methods of machining, casting, forging and welding, etc.

The future of DED

The aerospace sector uses high value material such as titanium. When making large parts through traditional processes like machining from billet, often up to 90% of the material is being wasted as chips. This inefficient use of material, machine and personnel time has to change.

The demand for more complex and robust parts, made faster, cheaper and at reduced weights requires a corresponding flexibility of process. This means that it is becoming more common to reconfigure production facilities, insert smart technologies, and upskill workforces as a way to meet this ever-changing and competitive landscape.

Though the cost of implementing DED has traditionally been expensive, driven mainly by high equipment cost, over the next five years we’ll see OEMs influence the supply chain and make the technologies more available off-the-shelf. Pilot programmes for the technology are already taking place globally, with early adopters such as BeAM and other end-users demonstrating that components can be built, tested and certified for use in aviation.

Making parts faster will help enable new design freedom to deliver greater fuel efficiencies and reduce the environmental impact of aircraft, so DED is certain to take off in the aerospace sector.

www.autodesk.co.uk