3D Printing and the Aerospace Industry

The aerospace industry is a main market for additive manufacturing. This is not only because this sector has a long history of an early adopter of this technology inventions, but also because it needs these kinds of inventions. Environmental performance restrictions, competitive market conditions and high manufacturing cost are just some of the challenges that aerospace faces today. And this is exactly where the benefits of additive manufacturing come to the core: shorter production time, no required additional tooling, material savings and cost-efficiency are just some of the good reasons why aerospace companies should integrate 3D printing in their production strategies.

The aerospace and defense (A&D) industry was an early adopter of 3D printing technology. The history of 3DP traces back to 1983 with some A&D companies beginning experimentation with the technology as early as 1988 (Newsela, 2013). Over the years, 3DP’s adoption has increased across industries, with the A&D industry contributing about 10.2 percent of AM’s $2.2 billion global revenues in 2012 (Terry Wohlers, 2013). Several reasons underlie 3DP’s relatively widespread adoption in A&D. 3DP provides the flexibility to create complex part geometries that is difficult to build using traditional manufacturing. It can build parts with designs such as internal cavities and lattice structures that help reduce parts’ weight without compromising their mechanical performance. 3DP machines produce less scrap than traditional machines, a critical attribute when using expensive aerospace materials such as titanium. Finally, 3DP’s impact on economies of scale and scope make it a natural fit for A&D, which, in contrast to other mass production industries, is largely geared toward customized production.

3DP’s current applications in the A&D industry range from manufacturing simple objects such as armrests to complex parts such as engine components. Applications such as printing aircraft wings and parts in micro-gravity are foreseeable in the future (Mark Betancourt, 2012). Figure shows the current and potential applications of AM in the Aerospace industry; this list is not exhaustive, as 3DP technologies and their applications are constantly evolving.

Currently, Aerospace companies are at different stages in adopting 3DP, and there is some debate about how real 3DP’s impact on traditional processes will be. On the one hand, Aerospace executives who are skeptical of 3DP’s potential may miss the opportunities the technology can offer. On the other hand, companies keen on benefiting from 3DP adoption may make hasty moves that do not align with their strategic imperatives. As the 3DP technology evolves, its applications are bound to change; however, the larger dynamics that we have identified related to products and supply chains will not. This assignment will help readers appreciate how 3DP can aid their companies in achieving performance, growth, and innovation goals and help leaders choose the paths that best suit their organizations’ value drivers.

3-D PRINTING PATHS TO A&D COMPANIES’ STRATEGIC IMPERATIVES AND VALUE DRIVERS

3-D printing is an important technology innovation whose roots go back nearly three decades. Its importance is derived from its ability to break existing performance trade-offs in two fundamental ways. First, 3DP reduces the capital required to achieve economies of scale. Second, it increases flexibility and reduces the capital required to achieve scope.

Capital versus scale: Considerations of minimum efficient scale shape the supply chain. 3DP has the potential to reduce the capital required to reach minimum efficient scale for production, thus lowering the barriers to entry into manufacturing for a given location.

Capital versus scope: Economies of scope influence how and what products can be made. The flexibility of 3DP facilitates an increase in the variety of products a unit of capital can produce, reducing the costs associated with production changeovers and customization and the overall amount of capital required.

Changing the capital versus scale relationship has the potential to impact how supply chains are configured, while changing the capital versus scope relationship has the potential to impact product designs. These impacts present companies with choices on how to deploy AM across their businesses. The four tactical paths that companies can take are outlined below.

Path I: Companies do not seek radical alterations in either supply chains or products, but may explore 3DP technologies to improve value delivery for current products within existing supply chains.

Path II: Companies take advantage of scale economics offered by 3DP as a potential enabler of supply chain transformation for the products they offer.

Path III: Companies take advantage of the scope economics offered by 3DP technologies to achieve new levels of performance or innovation in the products they offer.

Path IV: Companies alter both supply chains and products in the pursuit of new business models.

Traditionally, Aerospace companies have deployed 3DP to create value through path 1 by leveraging 3DP primarily for concept modeling, prototyping, tooling, and production of select end parts. Companies on this path are at different stages of 3DP adoption. While a few are using 3DP only for prototyping, others are using 3DP for short-run production.

In the medium term, with advances in 3DP and materials, Aerospace companies are likely to move from path I to path III in order to develop complex products with improved functionality, even new products altogether, without any major changes in their existing supply chain structures. A few leading Aerospace companies are already pursuing path III, and we expect increased momentum in the medium term.

Companies might also benefit in the area of maintenance, repair, and overhaul through the possibilities for cost-effective distributed production enabled by 3DP. Demand-driven production of spares through 3DP could be relevant for low-volume, complex parts; spares for out-of-production legacy aircraft; or spares required at remote locations.

In the long term, Aerospace companies are likely to deploy path IV—that is, they could pursue product customization along with on-demand 3DP that will likely lead to supply chain disintermediation and the evolution of new business models.

Path I: The path currently pursued by most A&D companies

Reduced time to market: 3DP helps companies quickly build prototypes with the required fit, form, and functionality, thereby accelerating design cycles, reducing time to market, and giving organizations a competitive advantage (Deloitte University Press, 2014) Research has shown that when Aerospace companies switch from traditional manufacturing to 3DP, they could benefit from time savings in prototyping ranging from 43 percent to 75 percent, depending on the conventional techniques used (Stratasys Inc.,2014)

For example, when the Defense Advanced Research Projects Agency (DARPA) asked for proposals to improve the design of vertical takeoff and landing (VTOL) aircraft in 2013, Boeing made prototype by using 3DP, whose construction would have otherwise taken several months, in less than 30 days (Chris Haddox, 2013)

Complex-design tools: 3DP’s ability to create free-form designs helps in building tooling fixtures that are difficult or impossible to produce with traditional machining techniques. For example, traditional machining can create cooling channels only in straight lines, thus making it difficult to optimize fluid flow in corners. 3DP can create cooling channels that conform to the curvature of a part, a feature that is especially important for engine parts.

Flexibility of design iterations: 3DP offers the flexibility to design and test products as many times as required, helping Aerospace companies reduce risks and uncertainties and improve product functionality at lower costs. With changes in software design files, companies can undertake multiple design iterations without expensive retooling. For example, NASA used 70 3D printed parts (such as flame-retardant vents, camera mounts, and housings) for the Mars Rover test vehicles (Richard E. Crandall, 2013)

Tooling at lower costs: 3DP not only enables companies to quickly design and test products, but also helps bring down the cost of manufacturing tooling and fixtures (Mark Cotteleer, 2014). A case in point is offered by the repair company Advanced Composite Structures (ACS). ACS produces the majority of its tools using 3DP, leading to overall cost savings of 79 percent and lead time reduction of 96 percent compared with traditional tooling (Stratasys Inc., 2013). Tooling using 3DP is particularly relevant for short-volume applications in the Aerospace industry.

Overall, path I, a starting point for 3DP adoption, leads to improved performance by reducing design and development costs and accelerating the speed at which cash flow can be realized without requiring significant changes in companies’ products and supply chain structures.

Path II: Supply chain evolution - Limited 3DP impact expected in the medium term

The Aerospace industry structure involves the manufacture and assembly of complex systems and sub-systems at select locations; the storage of parts in centralized warehouses; and maintenance, repair, and overhaul by skilled labor at relatively few locations. Boeing and Airbus aircraft typically consist of some 4 million parts sourced from across the globe. To avoid having an aircraft grounded, airlines commonly maintain an inventory of spares, some of which remain unused, and sometimes become obsolete with new aircraft designs. 3DP addresses the issue of warehousing and inventory obsolescence costs by enabling on-demand manufacturing where required. In line with Pareto’s 20/80 rule, 3DP can co-exist with conventional manufacturing to make Aerospace companies’ inventories leaner and save warehouse space (S. Hasan, 2008)

In the medium term, as 3DP machines become less expensive, aircraft maintenance, repair, and overhaul processes could benefit from cost-effective distributed production. Demand-driven production of spares through 3DP is relevant for low-volume, complex parts; spares for out-of-production legacy aircraft; or spares required at remote locations.

Path III: Product evolution – 3DP raising the bar for product performance in the medium term

Currently, a few leading companies are looking for ways to integrate 3DP into their mainstream applications to produce end parts with the required fit, form, and functionality. 3DP applications in the Aerospace industry range from manufacturing engine components to food trays. In the medium term, with improvements in 3DP technologies and materials sciences, an increasing number of companies are likely to adopt path III and leverage 3DP to improve product performance without making significant changes to their supply chains.

Complex-design parts: 3DP enables product designs and dimensions that are hard to create through traditional manufacturing, thus transcending existing design and manufacturing limitations (Mark Cotteleer, 2014). In traditional manufacturing, some designs that are optimized for topology are not feasible to manufacture due to their complex shape and design. However, with 3D printed parts can be designed not to accommodate manufacturing capabilities but to deliver maximum performance (D. Brackett, 2011)

Intricate geometries: Parts with designs such as internal cavities and lattice structures can be fabricated using 3DP. The 3DP process, while maintaining the parts’ strength by providing support only where required, can keep the parts’ weight low. For example, while producing Airbus A320 nacelle hinge brackets, EADS used direct metal laser sintering (DMLS) to build an optimized design that brought down the part’s weight by 64 percent while maintaining its strength and performance (Michael Molitch, 2013)

Waste reduction: Aerospace parts are built using expensive materials such as titanium, and it takes cost and effort to recycle scrap produced during machining (Abhiram Mokasdar,2012) Conventional machining can entail a scrap rate as high as 80–90 percent of the original billet; 3DP can bring the scrap rate down to 10–20 percent.

Part simplification: 3DP’s ability to manufacture multiple Aerospace parts as a single component, thereby reducing assembly effort, is another product-enhancement attribute. Typically, it is easier to modify a single-component product than a system built out of multiple components; hence, uncertainty in demand becomes more manageable. A classic example is GE’s additively manufactured fuel nozzles, which are additively manufactured as a single part; they formerly involved the assembly of 20 different parts (Kevin Michaels, 2013)

Improved functionality with embedded electronics: Ongoing advances in additively manufactured electronics embedded in parts offer product innovation opportunities. The field of embedded electronics, particularly for unmanned aerial vehicle (UAV) applications, is gaining momentum.

Ease of product customization: The scope economies enabled by 3DP can allow companies to customize products to customer requirements in much lower volumes than possible with traditional manufacturing. Companies that seek to develop customized versions of existing products, or develop new products altogether, need not change their production machinery.

Overall, improved product functionality as well as the development of new products using 3DP will offer opportunities for product innovation as well as revenue growth in existing and new market segments. Progress down path III can improve companies’ market responsiveness, thus enhancing their performance and prospects for growth.

Path IV: Combined supply chain and product evolution – 3DP’s long-term role in business model changes

In the last 30 years, 3DP applications have expanded from rapid prototyping to rapid tooling to end-part production as well as to the production of replacement parts. Path IV, “business model evolution,” foreseeable in the long term, is the most significant path in terms of its impact on Aerospace companies’ products and supply chain structures.

Collaboration with suppliers to create new products using 3DP: Currently, companies are using 3DP to improve the functionality of existing products or to build customized products. Going forward, this will continue. Additionally, in the long run, as 3DP technology improves, companies will likely take a step forward and leverage 3DP for designing new products altogether that are difficult to design and manufacture through conventional techniques. Aerospace companies are likely to collaborate with their suppliers and 3DP providers to build improved or new products using 3DP.

Acquisition of niche 3DP providers to build in-house AM capabilities: On path IV, Aerospace companies may also choose to acquire select 3DP players to improve their in-house 3D capabilities for critical applications, thus leading to some degree of supply chain disintermediation. For example, in early 2013, GE Aviation acquired Morris Technologies and Rapid Quality Manufacturing (RQM); both companies had earlier supplied additively manufactured parts to GE. GE Aviation also plans to triple its AM staff over the next five years from a headcount of 70 in 2013.

INCREASING AM ADOPTION: CHALLENGES AND POTENTIAL SOLUTIONS

3DP’s ability to manage small volumes, create complex designs, and fabricate lightweight but strong structures makes it a natural fit for the Aerospace industry, which is not a mass-production industry in the typical sense of the term. In its current state, the technology faces some challenges associated with size and scalability, high material costs, narrow range of materials, limited multi-material printing capabilities, and consistency of quality. Continuing advances in 3DP technology and materials science are likely to address these limitations and are expected to drive wider adoption of 3DP in the Aerospace industry.

Size limitations: 3DP underperforms traditional manufacturing when it comes to the production of large Aerospace components (Richard Hague, 2014). 3DP providers are focusing their R&D efforts on addressing the size limitations of existing 3D printers. Lockheed Martin is working with Oak Ridge National Laboratory (ORNL) on a big-area additive manufacturing (BAAM) system in which multiple deposition heads work in coordination to build large parts in an open environment, unconstrained by the typical envelope size (Christopher Holshouser, 2013).

Scalability limitations: Aerospace companies that use traditional manufacturing and sourcing methods face the challenge of stocking large inventories, a majority of which may be unused. On the other hand, 3D printers may not be able to scale up production when required. 3DP service providers are working to improve the build speed of existing systems to support the industry’s bulk-production needs.

Narrow range of materials and high material cost: 3DP predominantly uses a narrow range of polymers and metal powder to manufacture Aerospace parts, and the costs of these materials are much higher than that of the materials used in traditional manufacturing methods. In 2013, AM thermoplastics cost about $200 per kilogram, while those used in injection molding cost only $2. similarly, the stainless steel used in AM costs about $8 per square centimeter, which is more than 100 times the commercial-grade stainless steel used in traditional manufacturing methods.

Limited multilateral printing capability: 3DP systems that can print with multiple materials at a time offer huge design flexibility. Currently, only a few such systems are available. Advances in multi material printing capabilities will help designers make a part using different materials with varying properties. For example, one section of an aerospace part can be built from a material with flame-retardant properties, while other sections can be made of an extremely lightweight material (Hod Lipson, 2012)

Quality consistency: Quality consistency issues, especially in producing fully dense metal parts, result from excess heat that leads to stress and voids, particularly on layer boundaries. Repeatability can be improved by embedding controls within the machines so that in-situ dimensional accuracy is ensured, as well as by subsequently conducting automated inspections.