Lithoz CEO Johannes Homa: "There are three things that are important for ceramics: quality, quality, quality."

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“It’s not a sprint, it’s a marathon,” Lithoz CEO Johannes Homa says mid-way through our conversation as the sun beams down on us through the southwest-facing window in Lithoz’s Vienna showroom.

But the week, inclusive of the AM Ceramics Conference, has flown by.

It is late Friday afternoon, the day after the 2023 AM Ceramics Conference came to a close and Homa is in a buoyant mood. Save for one late cancellation, which would only allow more time for networking, the event ran without a hitch.

Kicking off with a workshop morning at the company’s showroom, the remainder was dedicated to a succession of presentations delivered by manufacturers and academics at Kleines Haus der Kunst close to the city centre. Not all on stage used Lithoz 3D printers, or at least not exclusively, but all were working with ceramic 3D printing. Of the audience, not all were working with ceramic 3D printing, but all at least had a serious interest in the technology.

There were about 100 delegates at the venue – the former headquarters of the Austrian Traffic Office reimagined as a setting for meetings, exhibitions, and celebrations. The AM Ceramics Conference managed to be all of those things: a meeting of minds, an exhibition of what ceramic 3D printing can do, and a celebration of the progress being made.

“We want to engage the industry and the community – not only industry, the community – to talk frankly and honestly,” Homa begins. “Bringing the industry forward by networking and by getting each other engaged. Everybody brings something and together [we] make something bigger. This was the idea.”

It has always been the idea. The AM Ceramics Conference has been running for multiple years, with Homa and his team trying to work out exactly when and where they have held the event since its inception as we sit down to commence this interview. There have been at least seven in-person events, and at least four cities visited, but enough for nobody to be quite sure off the top of their head.  

Regardless, Lithoz has seen the event mature year by year. Stepping on stage to open conference proceedings on the first afternoon, Homa noted that the AM Ceramics Conference is getting more professional as the industry does. As a gathering of industry personnel, the event merely mirrors the goings-on in the real world, with Lithoz doing nothing to censor them: good or bad.

Across the line-up several organisations highlighted their aerospace and medical applications – including Safran, Rafael and KLS Martin – but there was also a myriad of academics presenting the findings of a range of research projects. Among the latter, there was more than one presentation showcasing the imperfections of ceramic 3D printing technology (such as surface defects), with INSA Lyon’s Prof. Dr. Jérôme Chevalier suggesting ceramic additive manufacturing ‘still leads to larger defects than conventional manufacturing.’

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“This hurts when you see it,” Homa concedes, “but at the end, this is what drives the industry because you’re not only having the beautiful and nice marketing stuff but ‘hey, here are some things which you have to take into account.’ This year was the first time where it paid off. Assessing this year’s event, it was – especially the first day – so much about application, so much about things which are already in industry. This vision of industrial production is now coming through.

“Standards, quality, applications, all that is now coming to a point where it really makes sense, and this is now what we see. The conference is just the tip of the iceberg, but this tip of the iceberg is coming more and more in the direction of serial production, quality assessment, and standards.”

Among the applications on show were ceramic pre-forms (Safran), investment casting tools (Access), space reactors (BAM Bundesanstalt für Materialprüfung und-forschung), dental prosthetics (Charité Berlin) and orthopaedic implants (Sinaptic), while Homa also proffers the semiconductor, electronics, and luxury goods industries as additional target markets.

Having speakers detail the successes in developing these applications, while also explaining where and why a process generated defects is ‘healthy’ and [makes us] better’, according to Homa. Undoubtedly, it encourages conversation, and just surveying the intensity within which people network between sessions suggested that kind of discussion was forthcoming. At the evening social after the first day of conferencing, some attendees stayed until the hours.

One subject bound to be on the lips of the attendees throughout these networking opportunities was the dynamic between process and materials, a recurring theme throughout the conference. It was highlighted by both TU Wien’s Prof. Dr Jürgen Stampfl and INSA Lyon’s Chevalier, who opined, respectively, that ‘process must follow materials’ and ‘process optimisation is key for rheological control’ in ceramic 3D printing processes.

“The ceramic industry has an innovation blocker.”

The ceramic processes concerning Lithoz are its Lithography-based Ceramic Manufacturing (LCM) process and Laser-Induced Slipcasting (LIS) process. LCM works by dispensing a ceramic-loaded slurry, which is applied to a transparent vat with the movable build platform dipped into the slurry from above and then selectively exposed to a blue light. The layered image is produced via a digital micromirror device in combination with a projection system. Post-print, parts are debinded and sintered. The company’s Laser-Induced Slipcasting (LIS) process, meanwhile, sees a layer of water-based slurry of up to 1,000µm applied on the platform, with a high-speed CO2 laser selectively drying the slurry according to the layer pattern specification. After the part has been built up layer by layer, the build platform is raised to allow the excess slurry to flow off, before the green part undergoes the typical sintering process. 

The task for a company like Lithoz, then, is to optimise these processes for the materials being demanded by its users. The company is making good progress on this front, with its ceramic 3D printing technologies able to process zirconia-toughened alumina, alumina-toughened zirconia, hydroxyapatite, and silica grades, among others.

“Our philosophy is we are adapting the technology to the powder and not vice versa,” Homa says after reinforcing that: “There are three things that are important for ceramics: quality, quality, quality. These are the most important because ceramics is used when other materials fail. So, you’re always working in harsh conditions, harsh environments, and the materials properties always have to deliver.

“As a general assessment, I can say that it is already proven that additive manufacturing ceramics can meet the same quality as conventionally shaped ceramics. What is, of course, different is that the choice of materials is not yet there. It’s the maturity stuff.”

The 'maturity stuff' is the challenge confronting Lithoz as it looks to grow the number of users benefitting from ceramic 3D printing technology. Not only does more need to be done to open up the materials options for manufacturers exploring ceramic 3D printing, but the ceramics market is notoriously conservative and so pick up of a nascent technology can be slow.

“The ceramic industry has an innovation blocker,” Homa explains. “The innovation blocker is that most OEMs do not manufacture the ceramics themselves, usually ceramic business is contract manufacturing. This means the OEM gives the contract manufacturer [the job], they get a specification, and they look for different technologies, but they don’t have any design freedom or control over design. They need to copy [the design] exactly, so it takes time to penetrate, even if it’s problematic. I don’t complain. It’s just a matter of fact.”

It means that Lithoz often has to consult both sides of that dynamic, conveying the design possibilities to the OEM and then the manufacturing proficiency to the contract manufacturer. But once a breakthrough is made, users can get to grip with the technology fairly easily.

“Again, ceramic is a difficult material, but on the other hand, ceramicists are used to working with powders, which [can] make the adoption super-fast. We are not bringing a new technology in that sense. We are just bringing a new shaping technology; everything else is the same. You start with powder, you process the powder into slurry, you shape it, and then you debind and sinter it. So, there’s only one step different, and that makes adoption and everything much easier.”

With all that considered, Homa suggests that Lithoz's approach to prospective customers is ‘honesty, openness, and education.’ It tallies with the spirit of the AM Ceramics Conference, where Lithoz didn’t enjoy seeing images of defects displayed, but knew that the aforementioned combination would serve it well. Many that presented at the conference were part-way through research projects or had follow-up experiments to make, or wanted to optimise their industrial application of the technology further. And more than one presenter noted how Lithoz has been supporting their efforts.

“Since we are the market leader, the innovation leader, quality leader, I think we should have a different approach,” Homa says. “We need to not only harvest, but we need to seed. This, sometimes, makes more work, but our aim is not to sell machines. Our aim is to bring applications into the industry or to enable the industry to get their applications done.

“It’s a marathon. And we are quite successful. If you asked me what success in sales is, it’s not the number of machines we have sold, but it’s the number of customers who have two or more machines. One-time revenue? Okay, so what? This is not what we want.”

Read more: A decade of Lithoz: From 3D printing start-up to ceramics mass production