Why Additive Manufacturing Works for the Aerospace Industry

By Catherine
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By Catherine Bolgar

The aerospace industry is leading innovation in additive manufacturing on several fronts, including applications, materials, processes and design.

Additive manufacturing (AM), also known as 3D printing, may be well-suited to the aerospace industry, as long as the technology is certified and the cost comes down. This industry needs to make complex parts in low volumes from high-performance materials, while constantly seeking new ways to lower costs. While AM can cost more than traditional machining methods, it provides savings on materials—which can be substantial when using expensive metals such as titanium.

“There has recently been a real tectonic shift in the way large aerospace companies are investing in additive manufacturing,” says Kamran Mumtaz, lecturer in additive manufacturing at the Centre for Advanced Additive Manufacturing at the University of Sheffield, U.K.

Here are some areas of innovation:

NEW APPLICATIONS

AM originally was used to make plastic models and prototypes for basic form and fitting applications, but not for functional testing. Then AM was used to make plastic parts for functional applications. “More recently, it has been used for brackets, ventilation ducts and parts to hold wires and cables in place,” says Terry Wohlers, president of Wohlers Associates, a Fort Collins, Colorado, AM consulting firm. “Now, more parts are being made of metal AM, and I have seen no fewer than 25 new and innovative designs from one major aerospace company, alone,” he says.

Aircraft Turbine“With traditional manufacturing, many parts must be assembled from smaller pieces, because of the limits on what shapes can be cast, milled or molded,” Mr. Wohlers explains. “The technique of building in layers allows for parts to be combined digitally that could include 20, 50 or 100 parts into one, two or three parts,” he says. Fewer parts means big savings in expensive manufacturing processes, assembly, labor, inventory and maintenance, he says, adding that companies also are seeing a reduction in certification paperwork, because each part must conform to the strict requirements of regulatory agencies.

IMPROVED MATERIALS

Polymers, or plastics, are the most mature technology, but titanium 6-4, which can be difficult to grind or weld, is the most popular because of how well it works in AM, along with aluminum, nickel, stainless steel, and cobalt chrome.

New materials would require going through a qualification process, which takes several years. However, researchers are looking at feed stocks, optimal particle sizes and recyclability of leftover powder, says Bill Peter, director of the Manufacturing Demonstration Facility at Oak Ridge National Laboratory in Oak Ridge, Tennessee.

The laboratory recently made the largest 3D-printed component, which wasn’t a plane part but a trim tool to make the extended wing section of the new Boeing 777X. Traditionally made of metal, the AM tool was made of a composite of polymers with chopped carbon fiber. The AM tool is faster and cheaper to make than a metal one, Dr. Peter says.

Work is being done on AM composites that can withstand high pressures and temperatures as high as 176°C (350°F). “It would have tremendous savings for tooling in the composite industry for air applications,” he says. “Eventually, we want to understand how to bring the best materials to a problem set and come up with hybrid solutions,” using metals, polymers and ceramics.

AM makes it possible to alter microstructures as the materials are processed, which can affect their strength and flexibility. For example, one AM company “can blend two or more polymers and, consequently, can make one location of a part rigid and gradually transition to soft and elastic in another location,” Mr. Wohlers says.

IMPROVED PROCESSES

jet engineThe most common AM method for making metal parts is to lay a bed of powder and to melt it, layer by layer, with a laser or an electron beam, following a programmed design. However, the AM machines remain limited in size, so most of the parts made are small and in limited volumes.

“At Sheffield, we’re developing new manufacturing processes that improve on efficiency, build speed and enhance the properties of the components,” Dr. Mumtaz says. “We have a metallic-powder-bed manufacturing process, called diode-area melting, or DAM, that has the potential to be 10 times faster than conventional selective laser melting.”

Selective laser melting uses a single laser. Increasing speed requires a more powerful laser or integration of multiple lasers. “DAM replaces a single-point laser with up to 20 laser diodes. You can scan an entire powder bed faster,” he says.

The University of Sheffield also is building a 3D printer that uses high-speed sintering of polymers, with an infrared lamp on an inkjet printer, that’s about 100 times faster than laser sintering.

IMPROVED DESIGNS

Topology optimization is the mathematical technique employed to find the best way to “use minimal materials and minimal weight, but fulfill the needs of the part,” Mr. Wohlers says.

When grinding a part, 80% to 90% can be scrap. Additive Manufacturing is the opposite of that: you can do a highly convoluted, complex shape that can reduce materials and weight by 40% to 50% sometimes.”

INTERNET OF THINGS

AM machines are equipped with cameras and sensors to track the fabrication, point by point, including in the middle of a part as it’s being formed. “We’re capturing the information and using data analytics to see what’s going on,” Dr. Peter says.

Eventually, manufacturers would like to incorporate sensors into the parts, to monitor them for temperature, humidity, vibration or other data. However, sensors and metal or polymers are “dissimilar materials—and that makes things complicated,” Dr. Peter says. “While research activities are stepping up in the area of embedded sensors, there is a need for continued research to commercialize.”

 

Catherine Bolgar is a former managing editor of The Wall Street Journal Europe, now working as a freelance writer and editor with WSJ. Custom Studios in EMEA. For more from Catherine Bolgar, along with other industry experts, join the Future Realities discussion on LinkedIn.

Photos courtesy of iStock

Hey partner, can you keep a secret?

By Catherine
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By Catherine Bolgar


Original equipment manufacturers (OEMs) in aerospace and defense depend more than ever on suppliers to deliver innovation. That means sharing information and collaborating closely with third parties.

How can companies protect their intellectual property (IP) in such a fluid environment? The stakes are especially high in aerospace and defense, where technology is key to being competitive and is costly to develop. In addition, the nature of these sectors makes it difficult to apply some of the best practices used elsewhere to protect trade secrets.

“Aerospace and defense companies are somewhat unique in a couple of ways,” says Pamela Passman, president and chief executive officer of the Center for Responsible Enterprise And Trade, or CREATe, a Washington-based nongovernmental organization that helps companies around the world prevent piracy, counterfeiting, trade-secret theft and corruption. “There is the importance of collaboration and sharing across the supply chain” in general, she says. In addition, “there are incentives, at least in the U.S., in Department of Defense procurement to involve small and medium-size enterprises. Increasingly, it’s a highly regulated procurement space. That includes regulations around cyber risk.”

SMEs often are too small and unsophisticated to have adequate cyber and management controls to protect IP, Ms. Passman notes. If they are growing very fast they may not be as rigorous in vetting or training new hires as are some other institutions.

Larger institutions often have someone in charge of protecting IP. “Usually it’s part of the legal or research and development function,” she says. “We recommend having a cross-functional team that includes IP, R&D, cyber security, procurement and supply chain and human resources.”

Human resources’ involvement is important because insiders—who might be direct employees or contractors of either the OEM itself or suppliers—commit a lot of IP theft. A Feb. 2014 report by CREATe and PwC estimated that trade-secret theft amounts to 1%-3% of U.S. gross domestic product. “It’s significant,” Ms. Passman says. The U.S. Federal Bureau of Investigation made a film, “Company Man,” to educate companies about protecting trade secrets.

New hires usually sign agreements not to divulge IP, but those requirements need to be reinforced throughout their employment as well as when they leave the company, she says. That goes not only for employees of OEMs, but also for those of suppliers.

Companies need to be clear about what is protected IP:

It’s only a secret under the law if a company takes reasonable steps to keep it secret,” Ms. Passman points out.

Employees, especially scientists and authors of software, frequently look at their work the way artists do, assembling portfolios of their output to show to prospective employers. The problem is, under most [U.S.] state laws, when the employee creates their work in the course of their employment, the employer owns that work and it sometimes contains trade secrets, says Claude M. Stern, co-chair of the intellectual property litigation practice in the San Francisco office of at Quinn Emanuel Urquhart & Sullivan LLP, an international litigation-only law firm.

Employees might not be acting maliciously or with willful intent, but they would still be subject to a suit, Mr. Stern says, adding, “Companies are relatively rigorous about looking at their markets and who’s doing what. When a company comes up with something out of the blue that’s similar to my secret, I’m going to look at who’s working there.”

One way to protect IP is to be careful about who is privy to it and not to provide all the critical IP to one key supplier. However, companies in specialized sectors like aerospace and defense might not have a multitude of supplier choices. “In the global supply chain, sourcing is very challenging,” Ms. Passman says. “Certain materials or components may only be available in certain parts of the world.”

Companies also have conflicting priorities. While having multiple suppliers might better protect IP, many companies are reducing the number of suppliers in order to cut costs, according to a report by consulting firm Oliver Wymans. Aerospace and defense OEMs are pushing more responsibility and risk onto suppliers, and entrusting them with complete modules and systems, as well as R&D and innovation.

“In order to develop technology, it’s almost inevitable that the developer will disclose trade secrets to its vendor,” Mr. Stern says. “The question is, under what conditions? The protections are, or should be, in the contract.”

Patents help protect IP, but companies also need to protect evolving R&D that isn’t yet ready for patent application, or IP they don’t want to share at all.

Recourse for trade-secret theft can be difficult. The U.S. Defend Trade Secrets Act of 2016 took effect in May, giving companies greater ability to fight IP theft. The law lets companies file civil lawsuits in federal court; previously they had to sue in state courts, where laws varied. The federal government can file criminal charges for trade-secret theft.

The European Council adopted a directive on trade secrets in May to harmonize laws across the EU. Member states have two years to adopt legislation in line with the directive.

Some industries, such as those in mobile phones and business software, sue more frequently than others to protect trade secrets. Defense companies, by contrast, “are frequently, but not always, loath to sue their contractors,” Mr. Stern says. “They’re so close to their partners, they feel it would be mutually assured destruction. But in the appropriate case, we do see lawsuits, even among business partners.”

 

Catherine Bolgar is a former managing editor of The Wall Street Journal Europe. For more from Catherine Bolgar, contributors from the Economist Intelligence Unit along with industry experts, join the Future Realities discussion.

Photos courtesy of iStock