| abstract |
A method for sealing and protecting the surface of advanced composite materials against moisture and other contaminants. Advanced composite materials, which comprise high strength fibers such as graphite or boron fibers in a resin matrix such as epoxy or polyimide resins, suffer a performance loss when subjected to moisture. In high vacuum environments, such as in many outer space applications, resin binder outgassing may cause contamination of the overall device. Significant dimensional changes occur when these composite structures are used in environments with widely varying humidity levels. The disclosed method of preventing such degradation basically comprises the steps of undercoating the surface with a metal coating, fluxing the undercoat, forming a layer of molten metal on the undercoat then solidifying the metal topcoating. A seal coating substantially impervious to water and highly resistant to dimensional changes and corrosion results. |