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US4420352A Expired / Lapsed US ⏱️ 0.0 years remaining

Absorbable-susceptor joining of ceramic surfaces

Assignee: National Aeronautics and Space Administration
•
Filing: 1983-02-10
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Granted: 1983-12-13
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Expires: 2003-02-10
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Abstract

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.

Inventors

  • 👤 James E. Schroeder
  • 👤 Paul J. Shlichta

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-25 03:18
CPC Classifications
H; H05; H05B; H05B6/00; H05B6/02; H05B6/10; H05B6/105; C; C04; C04B; C04B35/00; C04B35/622; C04B35/653; C04B37/00; C04B37/003; C04B37/006; C04B2235/00; C04B2235/65; C04B2235/658; C04B2235/6583; C04B2235/66; C04B2235/667; C04B2237/00; C04B2237/02; C04B2237/12; C04B2237/122; C04B2237/30; C04B2237/32; C04B2237/34; C04B2237/343; C04B2237/345; C04B2237/348; C04B2237/36; C04B2237/50; C04B2237/59; C04B2237/597; C04B2237/70; C04B2237/708; C04B2237/76; C04B2237/765

Claims Analysis

Total Claims: 16
Claim 1
Independent Claim 77 words
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.
Claim 2
Independent Claim 77 words
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.
Claim 3
Dependent Claim 20 words
A method according to claim 1 in which the film is heated by applying radio frequency radiation to the assembly.
Claim 4
Dependent Claim 24 words
A method according to claim 2 in which the radiator has a low frequency below 1000 khz and only the susceptor film initially melts.
Claim 5
Dependent Claim 26 words
A method according to claim 2 in which the radiation has a high frequency above 1 mhz and the susceptor film and adjacent zones initially melt.
Claim 6
Dependent Claim 29 words
A method according to claim 2 in which the ceramic is an oxide or carbide of a metal of Groups II, III, IV and VIII of the Periodic Table.
Claim 7
Dependent Claim 31 words
A method according to claim 5 in which the ceramic is an oxide or carbide of beryllum, magnesium, calcium, barium, aluminum, cerium, thorium, zirconium, titanium, tantalum, iron, cobalt, nickel and ruthenium.
Claim 8
Dependent Claim 21 words
A method according to claim 6 in which the reactive gas is selected from an oxidizing, carbonizing, nitriding or sulfiding gas.
Claim 9
Dependent Claim 15 words
A method according to claim 2 in which the compound is identical to the ceramic.
Claim 10
Dependent Claim 19 words
A method according to claim 8 in which the ceramic is a metal oxide and the gas is oxygen.
Claim 11
Dependent Claim 21 words
A method according to claim 8 in which the ceramic is a metal carbide and the gas is a carbonizing gas.
Claim 12
Dependent Claim 21 words
A method according to claim 8 in which the ceramic is a metal nitride and the gas is a nitriding gas.
Claim 13
Dependent Claim 21 words
A method according to claim 8 in which the ceramic is a metal sulfide and the gas is a sulfiding gas.
Claim 14
Dependent Claim 13 words
A method according to claim 1 in which the susceptor film is perforated.
Claim 15
Independent Claim 60 words
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.
Claim 16
Independent Claim 60 words
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.

References Cited (Backward Citations)

US4347089A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1986-12-12 1987-06-13 1987-12-13 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1990-12-12 1991-06-13 1991-12-13 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1994-12-12 1995-06-13 1995-12-13 $7700.00 Window Closed / Lapsed

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