Save time on assemblies with fewer parts
Additive manufacturing allows designers and engineers to design highly complex components, including rocket and jet engines, with fewer manufactured parts. An example was the 3D printing of a jet engine fuel nozzle in 2012 where engineers reduced the number of parts from 20 to one. Not only did the component weigh 25 percent less, as a result, it reduced the need for parts assembly. In another design involving a new turboprop engine, multiple manufacturers were required to produce 855 components. 3D printing replaced these with just 12 parts, saving assembly time and cost at the same time.
Due to the efficiency and advanced capability of additive manufacturing, engineers are no longer constrained by cost increases associated with a more complex design. Indeed, aviation and aerospace often require sophisticated components consisting of many parts, each having to be manufactured separately and then welded together. Fewer joint welding reduces the risk of faults, making the component more reliable.
Build more with less
As AM technologies improve their production speed and size allowance, aircraft engineers and manufacturers will find it increasingly worthwhile to embrace 3D printing as the solution to increasing productivity and saving costs.
Virgin Orbit wants to have its thrust chamber assemblies fully fabricated using AM while Boeing’s progress into using 3D-printed parts for its 787s is expected to save them an estimated $2 million to $3 million per plane.
The annual growth in revenue for AM is expected to reach $8.7 billion by 2020, driven primarily by technologies like electron beam melting (EBM) and direct metal laser melting (DMLM). These processes are highly valued in the aviation and aerospace industry.
Better jet engines for airplanes
3D-printed fuel nozzles are making their way into the next generation of jet engines. An example is the GE9X which will feature 3D-printed fuel nozzles. As the largest and most powerful jet engine ever built, the GE9X is able to generate 100,000 pounds of thrust to propel wide-bodied jets at take-off. It is also about 10 percent more fuel-efficient. 3D-printed fuel nozzles will also feature in the LEAP-1A engines for the next generation of Airbus’ A320 passenger planes. Already, more than 12,000 LEAP engines and their 3D-printed fuel nozzles have been ordered and are in line for production.
Further to the successful development of the LEAP engine, two other engines, the Future Affordable Turbine Engine (FATE) and the ITEP, have also undergone prototype testing that incorporated the use of 3D-printed parts. AM processes were used to produce FATE’s turbine rig. Test results showed fuel consumption reduced by an unprecedented 35 percent while production and maintenance costs dropped 45 percent.
The ITEP engine, proposed for Apache and Black Hawk helicopters, had its T901 prototype tested using functional 3D-printed prototype parts. The new engine is expected to save 25 percent on fuel and 35 percent in production costs.
On-demand printing is making a major contribution to jet engine development and the production of end-use parts. It is cheaper and faster to produce engine prototypes using 3D-printed parts. End-use and prototype parts are also lightweight and highly durable, resulting in more efficient engines at a lower production cost.
Durable and lightweight airplane parts
In 2015, the Federal Aviation Administration (FAA) approved the first 3D-printed part for use in a commercial jet engine. This was a sensor housing designed by GE Aviation for a compressor inlet temperature sensor. Using cobalt-chrome alloy as the build material allows the housing to protect sensitive electronics from extreme airflow and icing conditions inside the engine. The part is to be used in more than 400 engines on Boeing 777 jets and manufactured using selective laser sintering (SLS).
Additive manufacturing simplifies the otherwise difficult process of manufacturing jet engine combustors. Other aircraft parts, such as those used in ducting systems, are also being 3D-printed. One key advantage is their reduced weight leading to energy-efficiency and lower carbon emissions.
Besides engines and parts, 3D printing is also used to produce special tools often required for aircraft manufacturing. In 2016, a 17.5 ft. x 5.5 ft. x 1.5 ft. (LxWxH) trim-and-drill tool was 3D printed in 30 hours from carbon fiber and composite plastics. It was subsequently certified by the Guinness Book of World Records as the largest 3D-printed solid object ever made. The tool was created to help construct the wings of Boeing’s 777X aircraft.
3D printing missions in space
In order to produce parts for space applications, manufacturing needs to be highly precise. This can be attained by using AM processes like EBM and DMLM that generate layers as thin as 20 or 40 microns––much thinner than the width of human hair––to build parts to close tolerances.
Additive manufacturing in aerospace applications is becoming commonplace as it offers engineers more flexibility in design and speed of production. An example is the 3D printing of a functional prototype of a rocket injector designed by NASA researchers at the Marshall Space Flight Center (MSFC). The two-piece injector was not only simpler than its 163-part predecessor, it performed comparably well, meeting rigid mechanical properties and hot fire standards.
In November 2017, the first 3D-printed satellite, the Tubesat-POD (TuPOD), completed its launch mission from the International Space Station (ISS). TuPOD is a 3U CubeSat deployment satellite produced straight from its CAD model without tooling required. AM offered the opportunities for designers to meet various challenges while building this unique mothership, including material selection, where traditional technologies would have limited them.
In 2014, astronauts aboard the ISS tested the feasibility of AM in space when they printed their first plastic part. 3D-printed objects from the ISS were returned to earth to test for mechanical and other characteristic impacts that may be caused by microgravity.
With its capacity to print parts millions of miles from Earth, on-demand printing could play a major role in man’s quest to explore Mars. It could lead to better risk management and cost control during these space missions. It could even be possible, in the future, to mine build materials from the red planet itself for use in 3D printing.