3 Tips on Additive Manufacturing from the European Space Agency

Lightweight 3D-printed metal structure manufactured by the UK-based Manufacturing Technology Centre, which recently established a new "one-stop shop" for 3D printing in space in a partnership with the ESA. (Image courtesy of Manufacturing Technology Centre.)

Additive manufacturing is poised to usher in sweeping changes across the manufacturing sector, the likes of which have not been seen since the advent of computer numerical control (CNC). Although the technology has been around for some time, the idea of using 3D printing as a production process is still novel. For that reason, it’s helpful to look for advice from those who’ve had considerable experience with additive manufacturing.

The European Space Agency (ESA) is one such organization. Adenit Makaya, advanced manufacturing engineer in the Materials and Processes Section TEC-MSP at the ESA’s Mechanical Engineering Department TEC-M recently presented some of his agency’s insights at this year’s IN(3D)USTRY – From Needs to Solutions.

Here are three specific pieces of advice taken from his presentation:

1. Don’t Think of Additive Manufacturing as a Process

“Through our studies, we realized that additive manufacturing is not a process,” said Makaya. “It’s actually part of an end-to-end chain of processes. It starts with the design, so you have to take design limitations into account: support structures, build volume and so on. This is where the experience lies, where a lot of your annual costs are, because it will pay off down the line in terms of manufacturing and qualification.”

(Image courtesy of the author.)

“After design, you have material supply,” Makaya continued, “which is very important because whatever defects you have in your powder will end up in your final part, which can affect its performance. You need to understand the properties of the powder and be able to trace it from the supplier to your final part.”

For the ESA, that means using powders that are already accepted for conventional processes, such as casting, rather than ones created specifically for additive manufacturing.

2. Use One Material Per Machine

The issue of powder qualification raised another useful insight, as Makaya explained:

“We were finding inconsistencies in mechanical tests [on titanium parts] and our powder screening processes couldn’t tell us what was wrong. Looking at the fracture surface, we noticed some small tungsten particles. Non-destructive testing of the samples also identified tungsten particles. It was all traced back to the machine which had been used just before our parts to produce tungsten parts. That’s something that we couldn’t screen for when we looked at the powder itself.”

(Image courtesy of the author.)

It’s for this reason that ESA recommends using one machine for each material.

3. Design for Post-Processing

There’s a lot of buzz about designing for additive manufacturing, but the ESA seems to be thinking farther ahead. Once again, this insight comes from the agency’s own struggles with additive manufacturing, as Makaya explained:

“You also have potential defects caused by blasting agents used for cleaning, which can get stuck in the cavities in your part,” he said. “In this case, you have ceramic balls and steel balls which were used to clean the surface of the part. So, you have to design your part thinking about the different steps that will be needed to arrive at the final part. If you have a cavity in your part, will it affect the possibility of trapping something?”

(Image courtesy of the author.)

If you’re just starting out with additive manufacturing, the above tips should help you avoid some of the more common mistakes for new users. If you’re thinking about adding metal additive manufacturing capabilities to your operation, here are 10 questions to help you get started.