The aerospace industry was an early adopter of additive technology, followed by the automotive industry. Where do these industries stand in relation to additive technology today? In a recent interview, David Giebenhain, global product director at Protolabs, shares his thoughts.

The aerospace industry has been working with additive technology probably longer than other industries. A key reason is that aerospace is a near perfect fit for extracting the value that additive manufacturing can provide. Additive technology is well suited to applications involving light-weighting, or optimizing heat exchanger performance, part consolidation, and building complex parts using materials like super alloys such as Inconel that can withstand extreme heat. For aerospace, every single one of these applications is a value-add to the performance of aircrafts and spacecrafts. Plus, the other primary driver is that the aerospace industry tends to produce products in low volumes, an area where additive is more cost competitive relative to traditional manufacturing processes. From that perspective, it’s logical that aerospace adopted 3D printing/additive technology early.

One trend in the aerospace industry is a shift to higher volume requests as well as requests for larger parts. Protolabs purchased two X Line platforms from GE Additive that has a large build volume, about 800 by 500 by 400 millimeters to accommodate exactly those types of requests. One uses mainly Inconel material, while the other works with aluminum.

The ability to build large parts also enables the ability to build many small parts in a single run, which really helps to reduce costs and maybe reduce cost barriers in other industries like automotive.

The aerospace industry started working to develop quality standards and validation processes for additive production parts early on, much earlier than most other industries. Today, despite still having a lack of widely recognized standards for additive production parts, most companies in the aerospace industry have developed their own criteria and requirements to qualify additive production parts. They still include FAA regulations in these requirements but they also tend to bring in other areas like casting requirements that they’ve used for decades.

The automotive market is a few years behind aerospace in the adoption of additive technology, although it has a lot of potential. Many applications in the auto sector still tend to be dominated by prototyping-use cases with activity coming from electric vehicle and autonomous driving system companies that are in a race to get their products to market fast.

Giebenhain sees several reasons for the limited activity with this market segment. With the consumer segments of automotive, like passenger vehicles, production volumes tend to be high, which makes additive technology less useful in terms of cost effectiveness. Processes like injection molding and casting suit this segment of automotive very well.

The other component is that although the complexity available in additive can still add a lot of value to automotive applications, it’s generally not quite to the same level as the value that it brings to the aerospace industry. For example, weight reduction saves the aerospace industry considerable money, but automotive weight savings is not at that same level. Thus, combined with higher production volumes, additive has a larger barrier to get over.

For now, additive suits the needs of automotive for custom looks and parts or personalization options.

The automotive industry explores binder jetting
An additive technology the automotive industry is most recently exploring is binder jetting. Giebenhain sees binder jetting technology as promising. The cost of parts made in this process is going down relative to laser sintering, particularly as production volumes go up.

There are some challenges with it. The binder jetting process requires a de-bind and sintering stage to get the parts fully dense. Throughout the sintering process, the parts can shrink and warp, so it takes a few iterations to perfect the pre-design that goes into the 3D printer to get the actual geometry desired.

Software is being developed to help predict the shrink and warp. Giebenhain sees a lot of investment here. As the software matures, Giebenhain thinks it will drive a lot of adoption in many industries, such as automotive.

Designing parts for additive manufacturing for aerospace and automotive
Engineers in the aerospace industry are clearly designing parts specifically for additive, leveraging the ability to handle complexity. They are eliminating manufacturability concerns, which do crop up from time to time, particularly on the metal side. As they eliminate potential manufacturing issues, it makes it easier for service providers to go straight into the printing process without having to iterate further to eliminate those manufacturability constraints.

Even so, there’s still some room for improvement, notes Giebenhain. “It’s still rare, at least at Protolabs, to see customers sending in parts designed with topology optimization or generative design for the purpose of a specific performance goal, such as exchanging heat or light-weighting. But I think as those software capabilities mature and become more widely available, we’ll start to see more parts targeted to take advantage of additively technology.

Design software
Topology optimization and generative design software can do a great deal to enhance a designer’s capabilities in using additive technology. Traditional manufacturing is limited in its ability to cope with the organic looking designs possible with topology optimization and generative design software.

“If you’re milling something, you have to slow down the speeds quite a bit to get those nice surface finishes out on a curve,” notes Giebenhain.

Beyond Topology optimization and generative design software, another form of software appears to be an obstacle to greater adoption of additive technology. For years, people blamed hardware as the obstacle. But that has changed as the technology develops better build speed.

“There will always be work to do on the hardware side,” notes Giebenhain. “For example, binder jetting is still in the early stages and will continue to be refined before it’s more widely used. Today, the issue is more about software. A lot of software capabilities on a standalone basis are fantastic. There’s great generative design software. There’s great build prep software. There’s great build simulation software to predict things like internal stresses that develop during the build process. There’s software to model the shrink and warp during a sintering stage. But what I think we’re missing is for all those capabilities to be integrated together so that the design software is also checking the build process for potential internal stresses.

“Because right now there’s a break between those two points. Customers can send us a part, and from a design perspective it would be great if we could produce it that way. But the way it’s designed, it’s simply challenging to build. Additions must be made to accommodate the design, such as support structures. How do you optimize those to get a good build the first time while also minimizing cost and reducing build times? I think there would be a ton of value in integrating all of those software capabilities. It’s hard to do, which I think is why it hasn’t happened yet. Different companies are developing different software and then of course they have to integrate into the hardware, which is another set of companies. It’s a big problem but it’s one I’m looking forward to see develop.”

Skill crossover
Additive technology suits a number of industries, each learning specific techniques for optimal design. In some cases, these techniques cross over and benefit designers in other industries. The medical industry, for example, is ahead of the curve relative to other industries.

“It’s about on par with aerospace,” says Giebenhain. “There’s a lot of value in terms of personalized medicine, implants, things like that. Such needs pushed engineers to move into additive early. But in general, most industries are still in their infancy with additive and there’s a lot to learn there. I think if we could get the aerospace, medical, automotive customers talking more openly about their additive strategies and additive processes, that would go a long way to giving these other industries a head start. Thinking about things like how do they determine when to use additive? How do they train their engineers to be so effective at designing for additive? How do they manage quality and validation for production?

“Those types of questions being answered at the start would give other folks who may not be as familiar with additive a big head start. And I think another aspect to this would be for these more advanced companies to describe their journey in getting to the point where they are now and going into detail on all the challenges they faced along the way, just in an effort to eliminate those same hurdles and barriers for these other industries as they begin their journey. There’s potentially even more value in knowing those pitfalls ahead of time, rather than just giving them the solution because the solution may differ for different industries but a lot of the barriers will be the same.

“I think it’s a tough ask to ask aerospace and automotive industries to share their special sauce, particularly if they believe that’s giving them a competitive advantage. One thing I’m hoping for is that as this additive expertise in aerospace and automotive and other industries becomes more commonplace and less of a differentiator within their industry, that hesitancy will fade and they’ll be more willing to share to industries like consumer electronics.

“Getting those cross-industry learnings can be difficult but now that the additive space is getting bigger and we’re having events like AMUG and RAPID, they’re catalyzing these types of conversations. Other organizations like America Makes are trying to foster these discussions and we’ve participated in some of those and with good results.”

Service providers like Protolabs help promote cross-industry learning as well. Many of these providers have large teams of application engineers who work with designers on the phone with advise of optimizing a design for a specific production process. And sometimes, those application engineers learn from customers who are advanced in applying additive techniques.

Leslie Langnau
Editor