Absorbable-susceptor joining of ceramic surfaces
AssigneeThe United States of America as represented by the Administrator of the National Aeronautics and Space Administration
InventorsJames E. Schroeder, Paul J. Shlichta
Life of this patent
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Abstract
An assembly (28) of ceramic surfaces (21, 23), particularly refractory metal oxides and carbides, abutting a thin sheet (22) of metal susceptor material are placed in a chamber (10) of an enclosure (14) containing inert gas (36). An r.f. coil (24) is activated by power supply (26) to melt the susceptor (22) and adjacent zones (40, 42) of the ceramic. Reactive gas such as oxygen or a carbonizing gas (38) is then fed to the chamber (10) and reacts with the susceptor (22) to form compounds (47) which disperse and dissolve in the zones (40, 42). On cooling, a strong joint is formed. The susceptor may contain inner perforations (58) and outer perforations (56) to aid in distribution of heat.
Claims14
A method of joining ceramic surfaces comprising the steps of:
- placing a thin film of metal susceptor material at the interface between the surfaces to form an abutting assembly, said metal being reactive with a gas to form a compound soluble in the ceramic;
- melting the film and adjacent zones of ceramic;
- reacting the susceptor with a gas to form said compound;
- dissolving said compound in the molten ceramic;
- and
- cooling the assembly to form a joint.
An apparatus for joining ceramic surfaces comprising:
- enclosure means for forming a gas-tight chamber;
- clamping means disposed within said chambers for holding an assembly of ceramic surfaces with a sheet of metal susceptor therebetween;
- first inert gas supply means connected to the chamber;
- second reactive gas supply means connected to the chamber;
- and
- induction heating means for heating said assembly.
Dependencies are inferred from the claim text.