Navy

High-performance composite material

Fiber-reinforced composite material uniquely resistant to both corrosion and fire

Materials

Galvanic corrosion

Bismaleimides (BMIs) are commercially available resins often used in structural parts for military vehicles because they process similarly to epoxy resins, while providing higher glass transition temperatures important for high-performance structural composites. However, cured BMI matrix materials are hydrophilic and when used in humid environments, such as in naval environments, result in galvanic corrosion to adjacent metal parts – especially when BMI composites are reinforced with electrically conductive carbon-based fibers and/or graphite fibers. Despite these issues, BMIs are widely utilized as a prepreg matrix in manufacturing electrical circuit boards and structural composites. They are also used as a coating material and as the matrix in glass-reinforced pipes, particularly for use in high-temperature and chemical environments.

Navy researchers have laminated BMI-carbon fiber composites with an outermost layer made of a self-extinguishing cyanate-ester (CE) matrix material and electrically/non-electrically conductive fibers (specifically excluding graphite and carbon fibers), to alleviate galvanic corrosion at the interface with adjacent metal parts. At the same time, the self-extinguishing CE layer reduces the composite’s vulnerability to fire. The self-extinguishing property of the CE matrix material is due to the crosslinked network and the high-char yield obtained at high-temperatures. The resistance to galvanic corrosion is attributable to the electrically non-conductive, non-carbon-based fibers used to reinforce this polycyanurate layer.

Do you have questions or need more information on a specific technology? Let's talk.

Contact Us