Apply online to license this technology
Scientists at the Army Research Laboratory have invented a new multicomponent barrier coating to protect engines from heat and water vapor.
The patented technology is available via license agreement to companies that would make, use, or sell it commercially.
In gas turbines and other heat engines, high-temperature oxidation resistant coatings are necessary to protect engine components and thereby improve reliability. Alloyed metallic coatings that form protective, slow-growing oxide scales such as alumina (Al2O3) and chromia (Cr2O3) have been designed and used as oxidation and corrosion resistant coatings, resulting in longer component service lives. However, metallic coatings typically have a useful temperature capability of less than 1,000° C., and may melt above 1,350° C.
Lightweight and high temperature capable silicon-base ceramics are desirable and can be used for improving gas turbine engine performance. However, thermal and environmental barrier coatings are critical when employing ceramic technology. Current environmental barrier coatings for silicon-based ceramics are based on barium strontium aluminosilicate (BSAS), with a mullite+BSAS intermediate layer, and a silicon bond coat adjacent to the silicon-based ceramics. One major problem with these coatings is their limited high-temperature stability of 1350° C. and below due to the poor water vapor corrosion resistance and low melting eutectic glass phases resulting from silicon interdiffusion and interface reactions in the mullite+BSAS/silicon system. Therefore, an environmental barrier coating with high water vapor stability and high-temperature capability is needed.
In response to this need, ARL researchers have developed a new multilayered coating system comprised of a multicomponent zirconia-base or hafnia-base oxide top layer, multiple sublayers and a bond coat layer that provides a protective coating solution for silicon-based ceramic components exposed to very high temperatures and high gas flow velocity water vapor. The system aids in phonon scattering, reduces thermal conductivity, and provides a buffer between the oxide top layer and silicon-based ceramic substrate. This, in turn, accommodates the thermal expansion mismatch and thermal strains between both layers.
- Improves component service life and reliability
- Protects from heat and moisture related damage
- Businesses can commercialize the technology by licensing U.S. Patent 7,740,960 from the Army
- TechLink guides businesses through evaluation and licensing; services provided at no cost