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Additive and Advanced Ceramics Design Guide

SiC Opportunities

Refractory ceramics exhibit unique high-temperature properties that enable high-performance energy and propulsion systems. Silicon carbide is such a representative refractory ceramic, as no degradation in strength is observed up to at least 1500°C, and there is a clear advantage in strength and fracture toughness at high temperatures. Thermal creep is essentially absent in silicon carbide until temperatures in excess of 1400°C are reached. Oxidation rates in air and steam or combustion environments are exceptionally low until the protective silica layer that forms in those environments melts at >1700°C.

While simple geometries (e.g., plate and pipe) from refractory ceramics can be produced today, components of higher complexity (e.g., heat exchangers, flanges, turbines) may not be readily produced using current technologies. The ability to use refractory ceramics for these components will greatly improve the thermal efficiency of these energy systems well beyond what is possible with conventional metal systems. High-temperature Ni-based superalloys are currently limited to ~800°C.

Silicon Carbide statue green body Laocoön and His Sons
Silicon Carbide green body of Laocoön and His Sons, a Greek statue.

Material Properties

Thermophysical Properties

For simple design and scoping, we recommend the following thermophysical properties roughly at room temperature. Click on the material tab to see the properties for that material.

Silicon Carbide

Maximum part size800×500×400mm
Part tolerance< 0.15mm
Density2.6 - 3.2g/cc
Coefficient of thermal expansion4.5ppm/K
Thermal conductivity35W/m-k
Strength> 200MPa

For more detailed design and prediction, we recommend utilizing past reports on our methods.


Our method does not introduce impurities to the feedstock. In fact, the process scrubs away almost all of the impurities present in the starting feedstock, except for a negligible increase in Cl and K impurities. It is clean enough to be used in nuclear fuels.

General Design Principles

Minimum Feature Size

We advise making the smallest feature size at least 1 mm.

SiC lattice
SiC lattice with very small internal features.

Minimum and Maximum Part Size

The printing beds have limited dimensions for different materials. See the above tables for details. Parts should fit inside the printing bed volume.

Very Large Parts

Larger parts can be produced by printing pieces and "welding" the pieces appropriately or by adding joining features.

Wall Thickness

  • Walls should be between 1-20 mm thick.
  • Thicker solid walls can be produced by creating walled cavities and embedding beads prior to the CVI process.
SiC shell.
SiC shell with thin walls.

Markers and Indicators

2D design features can be added to the surface of parts by using a modeled inset. Examples include logos, QR codes, or serial numbers. This avoids using stickers or other identifying features that are not as thermally or chemically tolerant as SiC.

SiC indicator dots
Indicators dots.

Cost Reduction

  • Cost is very roughly proportional to volume. Make your parts light and hollow. Use ribbing instead of solid parts.
  • Nesting lowers cost. If you need a lot of parts, it helps if they can fit snugly next to each other or inside each other.
  • Complex designs cost more than simple designs.

File Preparation

We will work with you to get your design into print-ready form. We prefer STEP and SLDPRT file formats, but also accept other 3D formats such as an STL. 2D drawings may also be used to create a custom 3D file for your review.


Our technology was born out of the US Department of Energy’s materials development for harsh environments. We are the only technology available for 3D printing highly pure, fully crystalline, and stoichiometric silicon carbide.

The method offers a high degree of freedom in geometric complexity without compromising on material properties. The method combines binder jet printing and chemical vapor infiltration (CVI) in a process capable of yielding a high-purity, fully crystalline ceramic — attributes essential for ideal performance in high-temperature and corrosive applications or in the presence of displacement damage.

The foundational R&D is documented in a series of papers and reports: