Metal additive manufacturing (AM) is still a technology that, for all intents and purposes, could still be considered in its infancy.
Great strides have been made over the last 10 to 15 years in this arena, and Wayland Additive is building on this technology with its own unique innovations.
Wayland’s team of engineers and physicists has developed and built a metal AM system from the ground up and is rewriting the rulebook on what a metal AM machine is capable of, according to Peter Hansford, director of business development for Wayland Additive.
The Wayland process is an electron-beam (e-beam) powder-bed fusion process, which offers significant advantages over laser-based processes to create
components. Wayland has dubbed that process NeuBeam.
“Because we come from an e-beam background — meaning the core of the technology is e-beam — we decided to build everything in house,” Hansford said. “We are not buying off-the-shelf components; we designed our own electron-beam column; we designed our own feed system. We designed our own in-process monitoring equipment. Because we started with a blank piece of paper, we needed to build a system from scratch, and we needed to decide what was going in there. We looked at it from a customer’s perspective. We built the system based around that, which included solving the problems of existing e-beam AM systems.”
Traditionally, one of the biggest problems with existing electron-beam processes is the charge from the beam can attach itself to all the particles in the powder bed, causing them to repel each other, so they scatter, according to Hansford.
“The traditional way of resolving that would be to sinter those particles together and to conduct the charge away,” he said. “The problem with doing that is you’re working at an elevated temperature, and you end up with this cake of sintered powder, and the parts get stuck inside the cake, which is hard — and time-consuming — to remove with the necessary and arduous post-processing requirement. What we’ve done is develop a system where we are able to fully neutralize the charge — hence the name NeuBeam or neutral beam.”
Keeping temperatures down
The NeuBeam process has the advantage of being able to keep the powder loose while also keeping part temperatures high, according to Hansford.
“We can work at the right temperature for the part/material,” he said. “Fundamentally, I guess in a nutshell, we sit between a laser-based system and a traditional e-beam AM system. We’re in the middle. We have advantages of both. We have all the power of e-beam and its ability to move the beam around fast and to melt material with a lot of power. But you have the usability of the laser system. The parts are not stressed; they’re never under stress, because they’re always above that temperature. And then on the other side, we have loose powder, but we have no support structures to remove, and we don’t have to heat-treat the parts afterwards; they’re already stable; they’re already above the temperature they need to be.”
The problem with laser AM systems is the laser beam can create a plasma effect on the powder, according to Hansford.
“That plasma effect is very, very hot, but it’s immediately cold, because it’s in a cold process,” he said. “So, the parts are going hot, cold, hot, cold, hot, cold, all the time.”
This causes the parts to be unnecessarily stressed during the manufacturing process, so they have to be nailed down with supports to a build platform, and, the bigger the parts, the greater the risk of stresses, according to Hansford.
“And, obviously, the bigger the part, the bigger the start plates needed, the stronger the supports needed, and it’s just a difficult thing to do,” he said. “When the plasma’s on top of the powder, you’ll see it’s like a little mini volcano, and it creates ejections. They call it spatter. Then, you need a gas flow going across the top to get rid of the spatter, or else it’ll drop back down into your powder bed and contaminate it.”
Wayland’s NeuBeam process works under a vacuum, which avoids spatter issues, according to Hansford.
Wayland originally worked on an aerospace project based on titanium gear blanks.
“What they were looking at was production processes and trying to increase the lifetime of the gears,” Hansford said. “And that’s all about microstructure, and it’s also about weight savings, too. These two criteria are what we were working on. We found that we could print parts in a certain orientation, and it gave us much stronger parts, but you need to design for AM, too.”
Once Wayland developed the NeuBeam technology, the next challenge was making it marketable, according to Hansford.
“The technology is applicable when using original materials,” he said. “What’s happened in AM, in a lot of cases, and certainly with laser-based processes, is that there are so many compromises made on material choices. Because of the nature of the processes, they can’t process what would be the natural material to use for certain applications. You find people trying to find ways around that, and that invariably means: Let’s try and make an alloy of whatever. Let’s try this, so we can still process it. And what we’re finding, because an e-beam has so much power, we can process the original material. And then, for the end user, the only quandary is: Is a new process but a familiar material much better than a new process and a new material? It really takes that question away from the materials side.”
Since the technology is brand new, Wayland is continually discovering ways in which it is applicable, according to Hansford.
“Our technology really gives us an advantage when we’re talking about large parts, about bulky parts, and that’s exactly where we are effective,” he said. “And then in terms of materials — like tungsten, for instance — we can process tungsten and give you good, fully dense, crack-free tungsten parts that you couldn’t easily produce on a laser system. Then with materials like CM247, materials that are notoriously difficult to weld, or to connect; NeuBeam has enough power to be able to do that. So that’s really where we’re seeing the technology today; that’s where it’s got an advantage. Also, materials like copper. Copper on a laser system typically has to change the laser from a red laser to a green laser, but if you really need a pure copper, we can do pure copper.”
For industries that include aerospace and automotive, the process would be particularly useful in making gear blanks, according to Hansford.
“NeuBeam is a great way to create gear blanks. Because of the geometry — one axis is long, and one is short — they get stressed via a laser system,” he said. “We found that with the laser parts, they continued to move even after heat treating them, so trying to machine them was very difficult and a waste of time. Having NeuBeam, which is different to traditional electron beam AM, you’ve just got a very stable process. And that means you can control the temperature. If you are looking at microstructure and strength, for instance, we can tailor that to what you want to get or to the maximum you can get from the material. And that’s the difference. You’ve just got a lot more control.”
Another advantage to the technology is it includes scanning technology — for in-process monitoring — allowing a look at the topology of a build, according to Hansford.
“That can tell us things like porosity and swelling,” he said. “It can tell us about the amount of material we’re dispensing. The high-speed infrared cameras can give us very accurate temperature measurements, allowing us to witness the process and see far more detail during the build. And then we have back-scatter detection from the electron beam, so we’ve got three monitoring systems in there giving us an awful lot of information. And what that gives us is three things: One is rapid development of material properties, so if we’re dealing with a new material, we can develop the parameters rapidly, because we can see exactly what’s going on. Two, it gives us traceability, and a history of the complete build. And three, it gives us a chance to alter the cooling curve. If we alter the cooling curve of the parts, we can change the microstructure of the metal. If we cool fast, we get smaller dendrites, smaller crystals. If we slow the cooling cycle, we get larger dendrites. Therefore, we can change the properties of the parts through that cooling cycle.”
The technology is also useful for prototyping, according to Hansford.
“If you want to do something quickly, and you want to test a theory out, then it’s perfect for that,” he said. “But invariably, we designed this system as a production system, rather than a prototyping system.”
Hansford and the experts at Wayland Additive hope to present the NeuBeam technology as simply another tool in a manufacturer’s potential arsenal.
“It’s just different to subtractive; it’s just a different way of getting there,” he said. “And it’s only applicable where the cost makes sense, where the speed is correct, and the volume of parts are correct. You have to choose the right technology for the right job. And that’s no different with AM.”
Four-year history, decades of experience
Wayland is made up of people who have decades of combined experience, but the company itself has only been around since 2016.
“Wayland started in 2016, under the radar, within a high precision engineering firm in the U.K.,” Hansford said. “The company had been in operation for around a hundred years, and it was working within numerous sectors, including the semi-conductor, medical, and aerospace industries. When considering a metal AM system, the team was looking at laser systems and e-beam systems that were on the market. And they got some gear blanks built on a laser system. They’d been heat treated, and despite the laser parts being heat treated, they continually moved. Every time they attempted to do something, there was some slight movement in the blanks on the laser-based systems because they were still stressed.”
Wayland’s now CTO — Ian Laidler — decided e-beam was the way to go, but while looking at systems on the market, he found fundamental flaws within the system that he thought he could resolve, according to Hansford.
“Initially they undertook an internal project,” he said. “This was able to generate some government funding, which enabled Laidler to bring his team of people — experts in e-beam and hardware development — back together who had the capability to build a machine from scratch. That’s how they started, and they started with a project to build gear blanks.”
By using e-beam technology, the team was able to create stress-free blanks that not only started out as light weight, but Wayland was able to change some of the features to make them even lighter, according to Hansford.
Ready for challenges
From those origins, the NeuBeam process was developed, and Hansford stressed that Wayland stands ready to use the technology to solve any challenge thrown at them.
“If they’re coming to us with a challenge, it means they have a problem,” he said. “And it means that they haven’t found a solution. If we can help, and if we think we’ve got a solution to that, then we would explore it together, and work on a project, or we’d work on finding the right materials.”
With that in mind, Hansford hopes to have the NeuBeam technology launched to the market by January.
“The NeuBeam system, with electron beam, means you can move it around very fast, so you can produce parts very quickly,” he said. “But I think there are a number of things that have to happen before it’s applicable to multiple industries. And that will come down to material costs, surface finish, and accuracy. But the biggest advantage with the technology is the freedom you have; you can adapt the parameters, and you can change the geometry, and stop thinking about old methods of production.”
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