Additive manufacturing and its role within the Aerospace industry

The popularity of 3D printing has taken off in the aerospace industry ever since the last decade as the primary frontier of its applications. For too long, this industry has had countless barriers to entry due to tight regulatory standards set up for a good reason, even though it’s also been one of the early adopters of this enabling technology. Companies now use it to produce spares, parts that are needed in small quantities while requested on-demand.In fact, the aerospace 3D printing market is expected to climb at a compound annual growth rate of about 27 percent to more than $3 billion by 2022, according to Markets and Markets.

the benefits of 3D printing for this industry are surfacing in many different forms even outperforming traditional systems concerning likely production constraints and application hurdles with its end-to-end advanced 3D technology. Additive manufacturing techniques provide huge competitive advantages as they adapt so well to build any geometrical complexity and part design customization using vectorized 3D technologies. In fact, realistic achievements are possible with optimum use of raw-material, lighter weight products, multi-material inputs, ergonomic products, short production runs, mass customization, fewer assembly errors, lower tooling investment costs, all resulting in lower associated costs and more sustainable processes.

For instance, Emirates airlines explored 3D printing back in 2014 to produce interior components for their aircraft. It was found that such parts weigh 9-14% lighter than mostly used component parts. Spreading this weight savings over their whole fleet in consideration, it’s potentially saving millions every year just by employing 3D printed parts. This development is now fully approved with class 1 certification for commercial flight back in 2017. Meanwhile, NASA and SpaceX are also busy with their in house additive manufacturing programs on their rocket engines to launch in space. In 2018 NASA successfully hot fired its new 3D printed combustion chamber while SpaceX had tested its engine made with over 40% 3D printed parts. To analyze just how some of these solutions could be achieved, let’s consider how Additive manufacturing affects some of the stages within the product development progression: 

Design freedom 

A common phrase associated with additive manufacturing is that ‘Complexity is free’. It means designers are no more affected with any production constraints no matter how complex or intricate their design is. In fact, the more complex a design, the more designers should consider using additive manufacturing. Engineers at Boeing report they are now enjoying the new design possibilities 3D printing enables. “Design configurations that had once been un-producible were now possible,” wrote Richard Aston, senior technical fellow. “This new capability enabled engineers to ‘think additively’ and be creative in the development of structural solutions.”

Intricate parts with internal cooling channels or multiple passageways for various working fluids are some of the most difficult design features to produce using traditional systems. However, since additive builds in multiple axes simultaneously, internal channels be it for cooling, filtration or catalysts’ options in any unusual ways are much easier to build using layer by layer material synthesis till the final product is achieved as per the design model. 

Along with the same token, this process can be further extended to create internal voids or entrapped features that don’t require escape holes. one of the best ways additive manufacturing is flexing its perks happens to be such a critical design criterion throughout the product lifecycle. Using generative design and topology optimization programs, the part can be made with the minimum viable weight ratio by removing excess/unwanted material that is not required for its due performance. Depending on the design, this activity can save weight while adding strength and support to the design mimicking nature with varying porosity. Eg. Cellulose structures for well distributed stiffness.

Thanks to computational parametric design capabilities, aerospace engineers are simplifying systems’ components, experimenting with new, more effective structures and doing much more. Since additive manufacturing technology can handle any part geometry, this design freedom for engineers even allows them to learn from nature as a design guide. It's no exaggeration to say that3D printing in aerospace industry will be a key capability differentiator soon as it grants engineers a new enabling tool in their quest to develop designs and parts not usually obtainable by any other methods. 

Precession and reliability

As noted above, the aerospace industry is by far the most stringent and highly regulated sector for safety than any other mechanized industries. This is now especially true for the unmanned aerial vehicles like drones since they are also intended to fly fully autonomous. But in order to take off (no pun intended), drones need to meet the right qualifications list of design and manufacturing requirements to drive high confidence in an air vehicle's reliability sense which is considered a direct effect of design precision and material property.

One of the best performances of additive technology is its innate ability to build parts to the precise exactness of its 3D design model. We can almost consider the 3D model to be the soft-copy raw material input to the 3D printer and the good old saying could’ve never be proven more so valid than in this situation ‘what you get is what you put into it’. In fact, some of the industries where additive manufacturing can offer the greatest benefit are the industries that have the most extensive qualification and compliance requirements.

Although historically, most extrusion type 3D printers were not up to the task for precession due to rougher surface finish outputs, the additive technology has ultimately evolved to other types of printing systems like laser guided stereolithography and jetting technologies that come up with the most accurate builds well up to 8K resolution. 3D printing is now able to make products safe and compliant with inclusive regulations around the world.

Additive systems’ manufacturers are also providing high end raw material solutions censored for the specified design purpose, in order to answer the call on reliability. More and more composites and alloyed materials are being tested and proven to the end products task assigned to them being the most bespoke solution for the final product. Cyclic repeated tests also monitored to evaluate the reliability of individual components while at work. that's why many companies that deliver products and services within the aerospace sector strive to earn AS9100 certification. 

In 2012, Airbus decided to adopt the technology to help fill gaps in its production process. Teams installing systems on the first Airbus A350 XWB realized they did not have enough of the removable brackets that go between the aircraft’s systems and structure. So, engineers opted to 3D print the parts instead. Within two months, the engineers were able to propose the idea, create and manufacture prototypes, and evaluate them on a flight-test aircraft,Airbus representatives recount. In April 2014, one of Airbus’ 3D-printed parts took flight on a commercial Airbus aircraft for the first time. The part was a small panel installed behind the crew seat to keep the seat belt in place, but this was a significant step forward for Airbus’ 3D printing initiative.

Part consolidation

Most mechanical systems are comprised of numerous parts and sub-systems to help build up the final machine assembly. In a nutshell, a machine is a physical assembly of its internal and external components by means of systematic mechanism working towards its intended purpose. Although this has been the case for a long while, it often comes with an increased failure rate probability due to multiple linkages and mechanisms not to mention the long lead times taken to manufacture and/or repair them. 

Now that, industrial technologies are mature enough to produce any geometric part, the mechanical assembly that would normally have many parts fabricated as separate components and then brought together can be additively manufactured as a single unit with simpler design output, even if the product is quite complex.For instance, the 3D technology company VELO3D partnered with Sierra Turbines to develop next gen micro turbines whereby the original design went from 61 discrete parts to a single consolidated "uni-core" engine with significantly reduced production time. The final product was 40X more efficient, 50% lighter in weight with 10X more power to weight ratio due to its simpler design and eliminated weights of joints and fixtures. 

There's no telling what the future may hold so far regarding AM applications, but one thing is for sure: 3D printing is an already established production practice across industries to transform how companies manufacture their own custom products.Of course, as use cases increase and additional applications are discovered, even more benefits will be unlocked with improvised design and production approaches.