Quintus Technologies
"This is not the simplest of topics,” starts Peter Henning, Director of Marketing & Sales at Quintus Technologies, a company that has been specialising in high pressure technologies for half a century.
Around a decade ago, the Swedish company underwent a rebrand, adopting the name ‘Quintus’ in a nod to a secret 1947 project, code named under the company’s founding ASEA moniker, which led to the invention of a heat and pressure process for the production of synthetic diamonds. It was around that same time in 2015 that the company also began to seriously turn its attention to another emerging industry where it felt its technology could offer a significant advantage: additive manufacturing (AM).
“We started to discuss with our customers what our technology could offer them in terms of value,” Henning told TCT. “We increased our awareness and competence and we started to build not only a very strong experienced team in machine building, but also a team of material scientists that could apply those features to a machine and bring real customer value.”
Up until that point, the company had supplied lab style equipment to the AM market, but as the demand for AM as an end-use production process grew, and conversations continued, Quintus decided to develop a high-pressure heat treatment technology that could be deployed by industrial AM users, and combine the benefits of high-speed cooling with temperature uniformity,
“Our equipment can do what you normally do in two different processes,” Henning explained. “So it has obvious advantages, not only financial or sustainable, but also speed.”
Ultimately, what Quintus was offering to the AM market, as Henning describes it, was a solution to go from “printed product to a functioning, real-life application."
While Quintus had established itself in Hot Isostatic Pressing (HIP), a process used to eliminate the porosity in metals and ceramics to improve their mechanical properties, AM's unique demands meant there was work to be done around how the traditional HIP process works for AM and how to apply it.
“HIPing is a known technology to many in the industry and it is applied very late in the process,” Henning explained. “But there are so many advantages to our technology that are not really incorporated in the setup.”
The unique, as printed, microstructures of metal AM parts require different treatment considerations. While printing can be optimised to maximise part density before a part even leaves the build plate, HIP uses very hot gas under very high isostatic pressure to act on all surfaces and internal structures on even the most complex AM parts.
“You can design a process for the final step of HIPing,” Henning explained. “Those products, in most cases, come out much better. You have to think what does your entire process look like? People are investing a lot of money in process steps that don’t necessarily contribute to the performance of the whole product.”
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Stresses, porosity, cracking; these are all challenges that HIP aims to remove from additive parts while improving ductility, fracture toughness, elongation and fatigue life. Nickel-based alloys can be difficult to print without cracking, and even if you were to print parts with a high level of density, there is still a risk that porosities will occur. But HIP can be used to remove those defects.
“For AM we tend to see a lot of high performing alloys put into challenging applications where there's a high degree of geometric complexity,” Henning said. “You need to do it right. Just because it is HIPed in one way for a cast product, doesn't mean that this is the right way to get the maximum out of a printed part.”
Quintus’ HIP technology is being applied to a range of high-performance applications, particularly in industries like aerospace, medical and space, the latter of which is becoming a “significant part” of the business and “really contributing volume of parts.” Demand from those verticals is mirroring that of the AM industry itself: bigger parts, made faster. As print build volumes get bigger, the capability of AM-ready HIP equipment needs to follow and Quintus is continuing to grow with the same performance but at a larger scale.
“We are engineering something for a higher performance rate but it should be used [correctly]," Henning said. "Everyone is trying to replace one part by making it a new way but the real benefit is when you use the flexibility of AM rather than trying to replace a forged or cast part.”
Bigger parts are one thing, the next frontier is new materials. Printing of aluminium is growing but its high cooling rates can be difficult to deliver within a traditional quenching environment. Quintus says it is already working on low temperature solutions and fine tuning its process to respond to those applications. The next step is to scale.
“I'm convinced the best is yet to come when it comes to AM,” Henning concludes. “We are very committed to this industry.”
Hiperbaric
Additive's best ally
For Hiperbaric, having kept a close eye on HIP for some time, it was the promise of AM, bolstered by the design and manufacturing synergies between its flagship High Pressure Processing (HPP) technology for the food industry and HIP, that encouraged the development of its own technology in 2018 with the AM market in mind.
“The most demanding industrial sectors – medical implants, aeronautics, nuclear, military – are already benefiting from the advantages of AM and HIP, and the synergy between the two concepts provides an answer to all the technical and productive requirements of these industries,” Rubén García, HIP Project Manager at Hiperbaric told TCT.
García offers up examples of automotive parts where HIP has provided another level of confidence in part properties and reliability, and customers like Aenium Engineering, for who Hiperbaric's HIP technology has become a “decisive tool” for certifying materials and parts with the strictest quality and safety controls for the space sector. While
Hiperbaric’s 1 metre HIP unit means part size is rarely a challenge – and it is currently developing an even bigger system – he notes that there are some limitations for HIPing AM.
“Parts with sandwich structure configuration are not eligible for HIP since the interior is a mesh structure and it will collapse during treatment as a consequence of high pressure,” García explained. “Advanced ceramics present a challenge not only for HIP but also for AM. These materials such as silicon carbide, silicon nitride or boron carbide push the HIP equipment to operation limit which is to 2000 °C / 2000 bar and at this range the furnace component suffer severe degradation.”
Yet García believes HIP offers “enormous potential” for new AM applications and materials. Hiperbaric is currently working on an R&D project, DioSiC, which uses HIP to improve polycrystalline silicon substrates from Spark Plasma Sintering. Treating silicon carbide (SiC) with HIP is said to significantly improve its properties by eliminating any possible defects in polycrystalline SiC wafers. Solidifying that belief in AM even further, Hiperbaric has also adopted AM in- house to improve the functionality of fan and heat exchangers for the Fast Cooling technology inside its HIP systems.
As AM adoption progresses, García believes HIP has an important role. The future integration of AM to reduce costs for solid state batteries, for example, could see HIP applied to densify and consolidate different components. Today, for printed components in satellites, rockets and their respective engines, turbomachines and burners, the impact of HIP is already being felt.
“There are strategic materials and components in the space sector that can only be manufactured by AM in a specific way,” García said. “The key to this is Hiperbaric's HIP technology, which allows materials to be cooled very quickly using Fast Cooling technology, especially in materials whose capabilities may be impaired if they are not cooled quickly.
“This is where HIP becomes AM's best ally.”
