While exploring additive manufacturing (AM) for electric vehicles (EVs), we came across the “Dauerpower” project. It brings together the Fraunhofer Institute for Reliability and Microintegration (IZM), Bosch, and Porsche. Together, they developed a high-performance power inverter designed to meet the demanding requirements of next-generation EVs. Delivering peak outputs of up to 720 kilowatts, the inverter leverages silicon carbide (SiC) semiconductor technology alongside 3D-printed cooling components. At its core, the use of SiC transistors enables long-term load stability while significantly reducing energy losses. This project and recent coverage from 3D ADEPT Media prompted questions about manufacturing silicon carbide parts. Their potential extends well beyond semiconductors.
Known for its high hardness, silicon carbide is a compound of silicon and carbon used in several ceramic forms. Johannes Homa, chief executive and founder of Lithoz, distinguishes two main families according to their manufacturing route.
SSiC and SiSiC: two manufacturing routes
Here are the main differences he describes.
- Manufacturers produce sintered silicon carbide, or SSiC, by densifying fine powder at very high temperatures. Homa highlights its hardness, chemical resistance, and suitability for demanding high-temperature mechanical applications. In this interview, he cites strength retention up to approximately 1,600 °C as an indicative figure. The value depends on the grade and operating conditions; it is not a guaranteed service limit for every part.
- Silicon-infiltrated silicon carbide, called SiSiC, follows a different route. Liquid silicon infiltrates a silicon carbide preform containing carbon. It reacts with the carbon to create additional silicon carbide, while residual silicon fills the pores. Homa describes a composite typically containing around 10 to 15% residual silicon by volume. This reactive infiltration enables complex shapes with limited shrinkage. It differs from SSiC sintering. Residual silicon limits high-temperature performance. He gives an indicative service temperature of around 1,350 °C for these parts. Users must check this figure for their specific grade and application. Examples include industrial furnace components and kiln furniture, where size and thermal-shock resistance can outweigh the need for maximum mechanical strength.
Sarah Diener, head of additive manufacturing at Kyocera, highlights SiSiC for rigid structural components with low thermal expansion. In her account, design optimization can reduce weight through complex geometries enabled by additive manufacturing.
AM approaches to silicon carbide parts
First, SSiC – Sintered Silicon Carbide
Conventional manufacturing often processes sintered silicon carbide through Cold Isostatic Pressing (CIP), injection molding or pressureless sintering.
SiC 3D printing can be challenging, mostly due to the high temperatures needed for densification. It also requires specialized equipment and techniques. Due to these sintering constraints, it’s fair to say that SSiC (Sintered Silicon Carbide) is not yet common in industrial AM production.
“The properties of silicon carbide are especially relevant to developments in the industry today, in terms of hardness, its durability in extreme conditions, its semiconductive properties, its toughness and its very low thermal expansion coefficient.
It is especially interesting for additive manufacturing because the traditional method of manufacturing involves milling the material which is both slow and, because of the materials’ hardness, very tough on the tooling used. With 3D printing many forms can be realised in a very quick manner with much less wear on the tooling,” Eric Geboers, founder of CONCR3DE adds.
Candidate processes and post-processing
Candidate AM processes include Lithography-based Ceramic Manufacturing (LCM), Binder Jetting, Direct Ink Writing (DIW), and Stereolithography (SLA). Each requires post-processing to achieve the desired part. However, most applications of these technologies remain at the research stage.
Emphasizing the challenges at the post-processing stage, CONCR3DE’s founder said it requires specialized knowledge and kilns. “If you already process silicon carbide taking up 3D printing will be easy as it is known technology, if you are a new service provider looking to produce silicon carbide parts there will be a more steep learning curve. This can be solved by working with known kiln providers who possess knowhow on post processing silicon carbide, but there are some peculiarities to the material that are different than dealing with metals or plastics,” he adds.
Thermal and optical constraints of SSiC
Homa also emphasizes the thermal demands of sintered silicon carbide, regardless of the shaping technology. Conventional processes have longer experience with the material but face these thermal constraints too.
In this interview, he puts silicon carbide sintering at around 2,200 °C and recalls SSiC’s high-temperature properties. These processing conditions require demanding equipment and substantial energy. He presents silicon infiltration as another densification route: molten silicon penetrates a preform and reacts with carbon to form the SiSiC composite. This limits shrinkage, but residual silicon reduces the usable temperature range compared with the SSiC discussed earlier. Material and processing choices must therefore suit the part’s service conditions.
Speaking of lithography-based printing processes, he explained the challenge of the material’s dark color. It absorbs the light necessary to expose the layers.
Second, SiSiC – Silicon-Infiltrated Silicon Carbide
Most AM SiC parts today are SiSiC due to easier processing.
Homa told 3D ADEPT Media there is a growing interest in slurry-based technologies and their ability to process SiSiC. These technologies include LIS (Laser-Induced Slip casting) and LSD-Print (Layerwise Slurry Deposition). BAM (Bundesanstalt für Materialforschung und -prüfung) develops them, and Lithoz commercializes them.
“These two technologies are still in the early stages. Nevertheless, the current trajectory is promising. Research, development, and investment are accelerating, and once the supply of the material, the reliability of the process, and the post-processing chains are more established, we can expect to see rapid growth in the industrial-scale adoption of these technologies,” Homa notes.
Why binder jetting suits SiSiC
However, all experts contributing to this dossier mention binder jetting as the AM process that has successfully achieved SiSiC parts.
“SiSiC is not a classical ceramic”, Sarah Diener said. “It is not sintered but infiltrated with liquid silicon. The liquid silicon reacts with carbon in the printed preform and forms secondary SiC. The not reacted silicon fills the pores of the material. Unlike in polymer or metal AM, in ceramic AM, a heat treatment, classically a sintering step, is needed to create the final ceramic part. The AM method is basically used for shaping the part.
[Binder Jetting] is the perfect AM process for that material, as the used particle size is comparably high and thus the flowability of the material is good for the powder deposition. Due to the infiltration process, instead of a classical sintering step the porosity that is left in the part after printing is not a drawback but even needed.
Moreover, many SiSiC are large ceramic parts and thus binder jetting is also more suited than, for example, material jetting. Other methods like VAT are difficult to realize due to the high absorption of the SiC.”
Density as a key SiSiC performance indicator
Geboers completes these statements by highlighting a key performance indicator of the manufacturing process with binder jetting:
“There is a good technology match between SiSiC (silicon infiltrated silicon carbide) and binder jetting. Binder jetting silicon carbide body typically results in a porous green body, which is highly suitable for silicon infiltration, which is already a known process in the ceramic industry. And, because you are infiltrating with silicon rather than sintering, there is absolutely minimal shrinkage in the post processing stages. This, in turn, allows the user to make very large forms with high tolerances.
Printing and post-processing choices
A typical important performance indicator of a SiSiC part is its density which is influenced both by how the green body is made in the printer and how the post processing is done. Typically, a higher final density requires a more complex printing and post-processing strategy. A fairly straightforward SiSiC with a density of 2,8 g/cm3 can be achieved purely by printing an aqueous binder and then debinding and infiltrating.
Higher densities can be achieved via the addition of carbon in the powder and the use of particle-filled inks, which greatly increase the green density. Carbon can also be added to the green body by dipping parts in resin and pyrolyzing them – this process, however, involves rather nasty chemicals, and we at CONCR3DE have a strong belief in sustainability.
Our preferred method that we work out with customers is therefore the use of particle-filled inks, which allow the density to be above 3,05 g/cm3 – making them useful for even the semiconductor industry.”
Keeping densification routes distinct
CONCR3DE offers silicon carbide printing followed by silicon infiltration, from laboratory to industrial applications. Its documentation separately describes a sintered silicon carbide route, still under development, using spark plasma sintering for small dense parts. This process differs from SiSiC infiltration.
Key applications of 3D printed SiSiC – Silicon-Infiltrated Silicon Carbide parts
Industry already uses 3D-printed SiSiC (silicon-infiltrated silicon carbide) parts. Large-format printers, originally developed for sand printing, enable the process to scale. All three experts identify the semiconductor industry as the main beneficiary of this material. While not directly tied to SiSiC, Homa recently highlighted it as a key enabler in semiconductor applications in this conversation with 3D ADEPT Media.
Beyond the semiconductor field, Homa explains that components that require high thermal conductivity, strength (even at elevated temperatures), light weight, and wear resistance could benefit from this material.
Applications outside the semiconductor field then include nonlinear conductors, atomic energy applications, and space technology.
“We’re seeing growing interest from the defense and aerospace sectors, where SiC-based components are used in applications such as gun silencers, optics, rocket nose cones, heat shields, and body armor. Another high-potential area is the nuclear industry, and even the automotive sector is exploring its use—for example, in high-performance brake discs,” Geboers concludes.
Concluding thoughts
SSiC still holds promise for its superior purity and mechanical strength. But sintering limitations still hinder its path to additive manufacturing.
As SiSiC gains traction in additive manufacturing, adoption in defense, semiconductors, and optics points to its technical relevance and scalability. Binder jetting currently leads the way. Slurry-based AM technologies—like those explored by Lithoz—could open new pathways for processing even more complex or performance-demanding parts. As materials and machine capabilities continue to evolve, we’ll be keeping a close eye on how these technologies and more could further process silicon carbide and integrate into the expanding world of ceramic 3D printing.
Editor’s notes
Known for its lithography-based printing processes, Lithoz is a global provider of high-performance ceramic materials and 3D printers, committed to breaking the boundaries of ceramic production. We invited the company to this dossier because of the potential of its LIS and LSD-print technologies for SSiC. Although they are still in stealth mode with these technologies, the company is currently looking for partners who require SSiC.
CONCR3DE first came onto our radar four years ago for its work in the construction industry. Today, the company is expanding its installed base while qualifying advanced technical ceramics, including alumina, zirconia, and silicon carbide. By fine-tuning raw materials, binder chemistry, and printing parameters, CONCR3DE can produce both small, intricate components and large, complex parts. The company tailors their material properties to each customer’s application.
KYOCERA Fineceramics Europe GmbH, a subsidiary of KYOCERA Europe GmbH, a supplier of advanced ceramic components for the technology industry, recently established a process for the additive manufacturing of components made of silicon carbide (SiSiC) at its Selb location in Germany. Sarah Diener has been working on the AM of SiSiC for more than 8 years and is the team leader of the R&D group on AM at KYOCERA Fineceramics Europe in Selb.
Source: Kyocera, silicon carbide material properties.
Source: Zocca and Günster, Open Ceramics, 2024.
Technical documentation: CONCR3DE — SiSiC / SSiC ; Schunk — kiln furniture.
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