Metal-bonded, carbon fiber-reinforced composites

A method of bonding metals to one-dimensional carbon-carbon composites, which consist of a carbon matrix binder material reinforced with carbon fibers, said method comprising the steps of reactive ion etching to provide a carbon-carbon composite which is substantially free of said binder material in a zone extending to a depth below the surface thereof effective to provide a binding site for a metal and infiltrating said metal therein to fill a substantial portion of said matrix-free zone and provide a surface layer of the metal, whereby to form a strong bond between said carbon-carbon composite and said metal.

A method of bonding metals to carbon-carbon composites, which consist of a carbon matrix binder material reinforced with carbon fibers, said method comprising the steps of providing a carbon-carbon composite which is substantially free of said binder material in a zone extending to a depth below the surface thereof effective to provide a binding site for a metal, said matrix-free zone being provided by the selective thermal oxidation of said carbon matrix binder material without substantial oxidation of said carbon fibers, said oxidation being carried out at an oxygen partial pressure from about 0.02 to about 0.2 atmospheres, temperature from about 500.degree. C. to about 750.degree. C., and for a time from about 5 to about 120 minutes;

• and infiltrating said metal therein to fill a substantial portion of said matrix-free zone and provide a surface layer of the metal, whereby to form a strong bond between said carbon-carbon composite and said metal.

A method of bonding metals to carbon-carbon composites, which consist of a carbon matrix binder material reinforced with carbon fibers, said method comprising the steps of providing a carbon-carbon composite which is substantially free of said binder material in a zone extending to a depth below the surface thereof effective to provide a binding site for a metal and infiltrating said metal therein to fill a substantial portion of said matrix-free zone and provide a surface layer of the metal, said metal infiltration being accomplished by electrodeposition utilizing alternating forward (plating) current and reverse current cycles, said forward current cycles comprising a plurality of pulses separated by current-off intervals, said reverse current cycles comprising at least one reverse current pulse, said forward current pulses having substantially higher current density and shorter duration than said reverse current pulses, the time-averaged current densities for both the forward and reverse current cycles being in the range of direct current plating for the applicable plating medium, whereby to form a strong bond between said carbon-carbon composite and said metal.

A carbon-carbon composite, which consists of a carbon matrix binding material reinforced with carbon fibers,, a surface portion of which is substantially free of said matrix material to a depth effective to provide a zone for infiltration of a metal selected from the class consisting of rhodium, iridium, and alloys thereof, said metal filling a substantial portion of, and forming a surface layer over, said matrix-free zone, whereby said carbon-carbon composite and said metal are strongly bound, and further comprising an oxidation-stable, high-temperature resistant, low-vaporization-rate coating of lanthanum hafnate adherent over said metal.