SOFC Protection Coatings Based on a Cost-Effective Aluminization Process
Nexceris has developed an aluminization coating tailored for the SOFC market. Our AlumiLokTM coating technology uses simple slurry coating and heat-treatment processes to create coatings with strong corrosion resistance. These coatings produce the same microstructure and show similar results compared to other costly vapor and pack-aluminization processes. The AlumiLokTM coating can provide benefits to several different applications in the SOFC market, such as:
- Interconnect Seal Area coating, which integrates with active area coatings for complete IC coating solution
- Balance of Plant (BoP) coating, amenable to non-planar and complex BoP geometries
- Electrical Isolation, which when combined with overlay coatings to provide insulating interfaces
- Catalyzed supports, where the roughened AlumiLok surface is an ideal support for a range of catalysts
AlumiLokTM Coating Development
Our current work at Nexceris is focused on improving the uniformity of the diffusion coating to further enhance the applications and benefits of the AlumiLokTM technology. By improving the microstructure of the uniformity of the coating result in better performance for the coated part, including enhanced coking resistance which leads to SOFC performance validation. By using the AlumiLokTM coating, we have successfully increased coking resistance by greater than 10X over a baseline coating. Our AlumiLok coated BoP improves cell degradation, as demonstrated with experiments we have done using our 28cm2 NextCells and manifold set. The results show a marked improvement in the output resulting from the AlumiLokTM coated BoP tube after 100 hours of running, with greater improvement after 200 and 300 hours.
Nexceris is working to strengthen the production readiness of the AlumiLokTM technology. The AlumiLokTM coating works well on many steel alloys, along with Inconel and Incoloy. One of the great benefits of this technology as well is that it can coat parts of various geometries, such as planar sheets, expanded metals, foams, as well as tubular geometries and monoliths. It is very robust in being able to coat welded parts, and indeed stands up to being welded itself.
AlumiLokTM can be combined with other coatings to create unique capabilities. For example, when combined with insulating ceramic layers, AlumiLokTM can be used to electrically isolate portions of a component. This can be co-deposited with Nexceris’ ChromLokTM product to create insulating and conducting regions on the same metallic component. Similarly, Nexceris has successfully deposited conducting anode protective layers on planar interconnects with localized internal reforming regions enabled by AlumiLokTM pretreatment, creating multi-function devices and simplifying stack design.