Advantages of Additive Manufacturing

Since the advent of additive manufacturing, 3D printing hardware and material suppliers have considered the aerospace industry as an important target for their products. The definition of additive processing is also simple, machining services tailored to the needs of the aerospace industry, also known as 3D printing.

Aircraft are highly complex systems with a variety of parts, so they will benefit from cutting-edge developments in production tools and materials, especially those that can reduce weight or increase the strength of parts. Some 3D printing processes claim to achieve both.

Unfortunately, this does not mean that the aerospace industry is adopting additive manufacturing faster than other industries. In fact, since aircraft and their many components must undergo the most rigorous certification and testing procedures (for obvious reasons), 3D printed aerospace parts can take years or even decades to go from concept to implementation. The technology is there, but the knowledge gained from years of testing and observation is not. Therefore, it is much easier to implement additive manufacturing in lower-risk industries where fewer lives are involved.

While the implementation of 3D printed aerospace products may be slow, the parts that have been successful are already having a significant impact on the industry. From simple parts like 3D printed cabin walls to absolutely critical parts like additively manufactured metal engine components, AM is undoubtedly starting to take off in one of the most lucrative and fastest-growing industries in the world. This article outlines some of the ways AM is being used in the aerospace industry and how it could be used in the future.

1.Lightweighting vs. Strength Optimization

Additive and subtractive manufacturing differ in many ways, and the choice between 3D printing and traditional manufacturing is often a dilemma. However, one key difference between the two methods is their respective abilities to shape the internal geometry of a part.

3D printing is useful in industries like aerospace because it allows engineers to create parts that are partially hollow inside, which utilize complex geometric patterns to maximize internal strength without adding weight. Because 3D printers build parts from the “bottom up,” they can be used to create lattice-like structures inside parts like metal engine components or plastic cabin bulkheads. This is impossible using traditional processes like molding (because the liquid material fills the entire cavity) or machining (because the cutting tool cannot reach the inside without penetrating the outside).

The importance of these lattice structures cannot be overstated. When building aircraft, every gram counts against achieving maximum efficiency, but 3D printing can significantly reduce the weight of a part by using partially hollow lattice structures on the inside. The thin wires of the lattice weave can be arranged in a mathematically optimized way to maximize strength and reduce stress, ensuring that the lightweight part is just as strong (or even stronger) than a completely solid alternative. What’s more, the spaces between these wires are weightless, which means the overall weight of the part is reduced.

There are many examples of aerospace companies using 3D printing to create lightweight parts. In 2011, researchers at Boeing’s HRL Laboratories announced the development of a metal they believe is the “lightest material in the world,” with a density of just 0.9 mg/cc, about 100 times lighter than Styrofoam. “The trick is to create a lattice of interconnected hollow tubes with walls that are 100 nanometers thick, 1,000 times thinner than a human hair,” explained Tobias Schaedler, one of the researchers. As researchers continue to explore the possibilities of lightweight 3D printed lattice structures, aerospace companies will increasingly engage with additive manufacturing for both lightweighting and strength optimization.

2.Prototypes and Spare Parts

One of the biggest advantages of additive manufacturing (in any industry) is its ability to make parts in-house on demand. 3D printers can be installed anywhere and can operate largely autonomously, which means that lead times for 3D printed parts are very short. Aerospace companies are therefore able to quickly manufacture new versions of parts for immediate testing, ultimately shortening the R&D process and completing parts faster.

Faster prototyping is therefore one of the main uses of additive manufacturing in the aerospace sector, and the results are proven: according to additive manufacturing giant Stratasys, aerospace prototypes can be made using in-house 3D printing in about 43% less time than injection molding and CNC tooling, and about 75% less time than 2D laser cutting.

Another area where the aerospace industry has benefited from additive manufacturing is inventory maintenance. The average commercial aircraft is made up of about 4 million parts, but not all of them are made by the same manufacturer. This means that aircraft suppliers must stockpile a large number of spare parts in case the aircraft needs repairs. Purchasing these spare parts costs a lot of money, as does purchasing the real estate to store them all.

3D printers can provide a very useful solution in this area. By keeping a 3D printer on site, aerospace companies can simply keep a digital library of spare parts in a printable format (such as STL) instead of filling up giant warehouses with millions of expensive spare parts. In this way, companies can use 3D printed parts only when they are needed. This strategy of using digital spare parts libraries is slowly being adopted by many industries and will take decades to be implemented on a large scale, but the aerospace industry could be one of the biggest beneficiaries.