Bonding of carbon fibers to metal inserts for use in composites
Resin-impregnated carbon fiber composites containing metal inserts. Carbon fibers or a carbon fiber preform are bonded to a metal structural member. Once the carbon fiber-metal bond is established, the fiber-metal assembly or hybrid preform is impregnated with resin, to form an article in which bonding between the metal structural member and the composite remainder of the article is greatly enhanced. In a process embodiment, a metal insert, e.g. a steel insert, is provided in contact with particulate carbide-forming metal, e.g. titanium, and with carbon fiber segments. Then an electric current is passed through the carbide-forming metal particles and carbon fibers to heat them to a temperature above the melting point of the carbide-forming metal. This initiates an exothermic reaction, which forms liquid phase metal carbide. Subsequently the liquid phase metal carbide is cooled and solidified, thereby bonding the carbon fiber segments to the metal insert.