US3310433A - Ceramic article coated with silver containing oxygen and method of making same - Google Patents

Ceramic article coated with silver containing oxygen and method of making same Download PDF

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US3310433A
US3310433A US309716A US30971663A US3310433A US 3310433 A US3310433 A US 3310433A US 309716 A US309716 A US 309716A US 30971663 A US30971663 A US 30971663A US 3310433 A US3310433 A US 3310433A
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silver
molten
oxygen
electrical conductor
roughened
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US309716A
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William E Tragert
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General Electric Co
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General Electric Co
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    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
    • C04B41/009—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone characterised by the material treated
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
    • C04B41/45—Coating or impregnating, e.g. injection in masonry, partial coating of green or fired ceramics, organic coating compositions for adhering together two concrete elements
    • C04B41/50—Coating or impregnating, e.g. injection in masonry, partial coating of green or fired ceramics, organic coating compositions for adhering together two concrete elements with inorganic materials
    • C04B41/51—Metallising, e.g. infiltration of sintered ceramic preforms with molten metal
    • C04B41/5116—Ag or Au
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
    • C04B41/80—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone of only ceramics
    • C04B41/81—Coating or impregnation
    • C04B41/85—Coating or impregnation with inorganic materials
    • C04B41/88—Metals
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/04—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the coating material

Definitions

  • an electrical conductor comprises a ceramic member, a roughened exterior surface on the member, and a layer of silver with dissolved oxygen therein adhering firmly to the exterior surface of the member.
  • FIGURE 1 is a sectional view through an electrical conductor embodying my invention
  • FIGURE 2 is a sectional view of a modified electrical conductor
  • FIGURE 3 is a sectional view of a molten silver bath employed in my method of forming an electrical conductor.
  • an electrical conductor is shown generally at which comprises a ceramic member 11, a roughened exterior surface 12 on member 11, and a thin layer of silver 13 with dissolved oxygen therein adhering firmly to the exterior roughened surface 12.
  • Member 11 is composed of a ceramic material such as alumina or zirconia.
  • a roughened surface 12 is provided on member 11 by sandblasting the member.
  • a member with a roughened surface can also be produced by forming a green ceramic core, slip coating the core with a ceramic layer having larger grain size, and firing the coated core to provide a member 11 with a roughened exterior surface 12.
  • FIGURE 2 of the drawing a modified electrical conductor is shown which comprises a hollow ceramic member 14, a roughened exterior surface 12, and a thin layer of silver 13 with dissolved oxygen therein adhering firmly to the exterior roughened surface 12.
  • a bore 15 extends through member 14 which bore can be employed to bubble oxygen therethrough to a liquid silver electrode in a high temperature fuel cell.
  • FIGURE 3 of the drawing there is shown a container 16 in which silver 17 is positioned to form a molten silver bath.
  • Container 16 is made of a suitable material which withstands the temperature and effects of molten silver.
  • a non-porous ceramic such as stabili'zed zirconia is formed into and employed as container 16.
  • stabilized zirconia is a compound with a cubic crystal structure consisting of zirconiato which is added an oxide such as calcium oxide.
  • a specific stabilized zirconia for container 16 consists of zirconia to which is added 15 molecular percent of calcium oxide.
  • Silver 17 is heated to a molten condition to form a molten silver bath by means of an induction coil 18 surrounding container d6.
  • a tube 19 of a suitable material such as zinconia, alumina or stainless steel, is inserted into silver 17 when it is in molten condition.
  • Tube 19 is connected to a source 20 of a gaseous oxidant containing molecular oxygen, such as air.
  • a valve 21 is provided in tube 19 to regulate the flow of gaseous oxidants to molten silver 17.
  • a ceramic member 11 such as alumina or zirconia has its exterior surface roughened by sandblasting to provide an exterior roughened surface 12 thereon.
  • Member 11 with roughened exterior surface 12 is then dipped into the molten silver bath saturated with oxygen within container 16.
  • molten silver with dissolved oxygen therein is applied to roughened exterior surface 12.
  • Member 11 is wetted by silver 17 with dissolved oxygen therein and silver 17 with dissolved oxygen therein is retained on roughened surface 12.
  • Coated member 11 is then removed from the molten silver bath whereupon cooling a thin silver layer 13 with dissolved oxygen therein adheres firmly to surface 12. If desired, molten silver with dissolved oxygen therein can also be applied to member 11 by spraying or painting surface 12 thereof.
  • one end of the silver-coated ceramic member is inserted in a liquid silver electrode.
  • the other end of the conductor is connected to apparatus to be operated by the cell.
  • a separate conductor is connected between the cell anode and the apparatus to complete the circuit;
  • the portion of the conductor which is immersed in the electrode will have its associated silver layer portion in liquid state.
  • a portion of the silver layer adjacent to the immersed portion will also be in liquid state but will adhere to its associated portion of the conductor because of surface tension.
  • the subject conductor provides good contact with the liquid silver electrode and good electrical conduction.
  • a portion of the silver layer spaced from the electrode remains in solid state whereby contact can easily be made to an apparaus to be operated by the cell.
  • An example of an electrical conductor made in accordance with the present invention is as follows:
  • a method of forming an electrical conductor which comprises providing a ceramic member, roughening the exterior surface of the member, and applying molten silver saturated with oxygen to the roughened exterior surface of said member whereby a thin silver layer with dissolved oxygen therein is formed thereon.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Ceramic Engineering (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Structural Engineering (AREA)
  • Inorganic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Fuel Cell (AREA)

Description

In ve r7 to P: ill/fin: E. Tr-fier-t, His Attorney.
W. E. TRAGERT CERAMIC ARTICLE COATED WITH SILVER CONTAINING OXYGEN AND METHOD OF MAKING SAME Filed Sept. 18, 1965 7 4?! (CERAM/C MEMBER II/l/ 1 \xxx\ m\m v S/LVER-OXYGE/V LAYER March 21, 1967 United States Patent 3,310,433 CERAMIC ARTICLE COATED WITH SILVER CON- TAINING OXYGEN AND METHOD OF MAKING SAME William E. Tragert, Scotia, N.Y., assignor to General Electric Company, a corporation of New York Filed Sept. 18, 1963, Ser. No. 309,716 1 Claim. (Cl. 117-213) This invention relates to electrical conductors andmore particularly to electrical conductors for contacting molten metals.
This application is a continua-tion-in-part of my co v pending application filed Mar. 8, 1961, as Ser. No. 94,240, now abandoned, and assigned to the same assignee as the present application.
The maintenance of electrical contact with a molten metal poses a serious problem. For example, such a problem exists in a high temperature fuel cell employing an oxygen saturated liquid silver cathode. Noble metals are extensively soluble in silver while most refractory metals are subjected to rapid oxidation in an oxygen rich environment. This problem has been partially solved by a stainless steel conductor which provides a satisfactory contact. However, this conductor is only moderately good at cell operating temperature. Thus, it would be desirable to provide an improved electrical conductor for contacting a liquid metal electrode, particularly a silver electrode.
It is an object of my invention to provide an electrical conductor.
It is another object of my invention to provide an electrical conductor which is not subject to rapid oxidation in an oxygen rich environment.
It is another object of my invention to provide an electrical conductor which is not soluble in liquid silver.
It is a :further object of my invention to provide an electrical conductor which contacts satisfactorily .a liquid metallic electrode.
In carrying out my invention in one form, an electrical conductor comprises a ceramic member, a roughened exterior surface on the member, and a layer of silver with dissolved oxygen therein adhering firmly to the exterior surface of the member.
These :and various other objects, features, and advantages of the invention will be better understood from the following description taken in connection with accompanying drawing in which:
FIGURE 1 is a sectional view through an electrical conductor embodying my invention;
FIGURE 2 is a sectional view of a modified electrical conductor; and
FIGURE 3 is a sectional view of a molten silver bath employed in my method of forming an electrical conductor.
In FIGURE 1 of the drawing, an electrical conductor is shown generally at which comprises a ceramic member 11, a roughened exterior surface 12 on member 11, and a thin layer of silver 13 with dissolved oxygen therein adhering firmly to the exterior roughened surface 12. Member 11 is composed of a ceramic material such as alumina or zirconia. A roughened surface 12 is provided on member 11 by sandblasting the member. A member with a roughened surface can also be produced by forming a green ceramic core, slip coating the core with a ceramic layer having larger grain size, and firing the coated core to provide a member 11 with a roughened exterior surface 12.
In FIGURE 2 of the drawing, a modified electrical conductor is shown which comprises a hollow ceramic member 14, a roughened exterior surface 12, and a thin layer of silver 13 with dissolved oxygen therein adhering firmly to the exterior roughened surface 12. A bore 15 extends through member 14 which bore can be employed to bubble oxygen therethrough to a liquid silver electrode in a high temperature fuel cell.
In FIGURE 3 of the drawing, there is shown a container 16 in which silver 17 is positioned to form a molten silver bath. Container 16 is made of a suitable material which withstands the temperature and effects of molten silver. For example, a non-porous ceramic such as stabili'zed zirconia is formed into and employed as container 16. As it is known, stabilized zirconia is a compound with a cubic crystal structure consisting of zirconiato which is added an oxide such as calcium oxide. A specific stabilized zirconia for container 16 consists of zirconia to which is added 15 molecular percent of calcium oxide.
Silver 17 is heated to a molten condition to form a molten silver bath by means of an induction coil 18 surrounding container d6. A tube 19 of a suitable material such as zinconia, alumina or stainless steel, is inserted into silver 17 when it is in molten condition. Tube 19 is connected to a source 20 of a gaseous oxidant containing molecular oxygen, such as air. A valve 21 is provided in tube 19 to regulate the flow of gaseous oxidants to molten silver 17.
In accordance with the method of my invention to form an electrical conductor as shown in FIGURES 1 and 2 of the drawing, power from a power source (not shown) is supplied to induction coil 18 to heat silver 17 in container 16 to form a molten silver bath. Valve 21 is opened and supplies air which contains molecular oxygen to the molten silver bath. The oxygen is dissolved in the silver to saturate the silver with oxygen by bubbling the air into the molten silver bath.
A ceramic member 11 such as alumina or zirconia has its exterior surface roughened by sandblasting to provide an exterior roughened surface 12 thereon. Member 11 with roughened exterior surface 12 is then dipped into the molten silver bath saturated with oxygen within container 16. In dipping member '11 in the molten silver bath, molten silver with dissolved oxygen therein is applied to roughened exterior surface 12. Member 11 is wetted by silver 17 with dissolved oxygen therein and silver 17 with dissolved oxygen therein is retained on roughened surface 12. Coated member 11 is then removed from the molten silver bath whereupon cooling a thin silver layer 13 with dissolved oxygen therein adheres firmly to surface 12. If desired, molten silver with dissolved oxygen therein can also be applied to member 11 by spraying or painting surface 12 thereof.
I found that silver will not adhere to a ceramic member, such as alumina or zirconia, by dipping the ceramic members in a molten silver bath. However, I discovered that such a ceramic member with a roughened surface is wetted by molten silver with dissolved oxygen therein. Roughened surface 12 and the application of molten silver with dissolved oxygen therein produces upon cooling a thin silver layer with dissolved oxygen therein which layer adheres firmly to member 11.
In the operation of the conductors shown in FIGURES 1 and 2, one end of the silver-coated ceramic member is inserted in a liquid silver electrode. The other end of the conductor is connected to apparatus to be operated by the cell. A separate conductor is connected between the cell anode and the apparatus to complete the circuit; The portion of the conductor which is immersed in the electrode will have its associated silver layer portion in liquid state. A portion of the silver layer adjacent to the immersed portion will also be in liquid state but will adhere to its associated portion of the conductor because of surface tension. Thus, the subject conductor provides good contact with the liquid silver electrode and good electrical conduction. A portion of the silver layer spaced from the electrode remains in solid state whereby contact can easily be made to an apparaus to be operated by the cell.
An example of an electrical conductor made in accordance with the present invention is as follows:
The exterior surface of an alumina rod, which was one-eighth inch in diameter, wa roughened exteriorly by sandblasting. The rod was then dipped into a molten bath 0f liquid silver saturated with oxygen to produce a thin layer of silver with dissolvedoxygen therein on its exterior surface. Subsequently, this electrical conductor was immersed partially in the liquid silver electrode of a fuel. cell and connected to a simple decade resistor. A separate conductor connected the cell anode to the resistor. The cell was operated at a temperature of 1100" C. for a period of 40 hours during which the cell had a load voltage of 0.7 volt and a current density of 30.0 milli-amperes per square centimeter. The electrical conductor operated satisfactorily throughout the operation of the cell.
While othermodifications of this invention and variations thereof which may be employed within the scope of the invention have not been described, the invention is intended to include such that may be embraced Within the following claim:
What I claim as new and desire to secure by Letters Patent of the United States is:
A method of forming an electrical conductor which comprises providing a ceramic member, roughening the exterior surface of the member, and applying molten silver saturated with oxygen to the roughened exterior surface of said member whereby a thin silver layer with dissolved oxygen therein is formed thereon.
References Cited by the Examiner UNITED STATES PATENTS 1,536,749 5/1925 Austin 174-140 2,440,691 5/1948 Jir-a 11 7227 X 3,010,850 11/1961 Colbert et a1. 117-227 X 3,020,156 2/196'2 Rowe 117-227 X 3,021,233 2/1962 Fenity 11'7-227 3,124,478 3/1964 Cirkler et al 117227 X OTHER REFERENCES LEWIS H. MEYERS, Primary Examiner.
L. E. ASKIN, I F. BURNS, D. A. KETTLESTRINGS,
H. HUBERFELD, Assistant Examiner.
US309716A 1963-09-18 1963-09-18 Ceramic article coated with silver containing oxygen and method of making same Expired - Lifetime US3310433A (en)

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Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4050956A (en) * 1970-02-20 1977-09-27 Commonwealth Scientific And Industrial Research Organization Chemical bonding of metals to ceramic materials
US4908740A (en) * 1989-02-09 1990-03-13 Hudgins Richard D Integral composite structure with predetermined electrically conductive networks and method for producing same
US5044406A (en) * 1987-03-18 1991-09-03 Semiconductor Energy Laboratory Co., Ltd. Pipe made from a superconducting ceramic material
US5435889A (en) * 1988-11-29 1995-07-25 Chromalloy Gas Turbine Corporation Preparation and coating of composite surfaces
US5474975A (en) * 1987-04-01 1995-12-12 Semiconductor Energy Laboratory Co., Ltd. Method for manufacturing an elongated member from a superconducting ceramic material
US20080233403A1 (en) * 2007-02-07 2008-09-25 Timothy Dyer Method of Making Ceramic Reactor Components and Ceramic Reactor Component Made Therefrom
US20090242271A1 (en) * 2008-03-28 2009-10-01 Jan Vetrovec Lightweight electric conductor assembly
US20110220285A1 (en) * 2010-02-12 2011-09-15 Morgan Advanced Ceramics, Inc. Methods and systems for texturing ceramic components

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1536749A (en) * 1919-12-03 1925-05-05 Ohio Brass Co Insulator
US2440691A (en) * 1945-03-07 1948-05-04 Continental Carbon Inc Alloy metal film resistor
US3010850A (en) * 1952-10-29 1961-11-28 Libbey Owens Ford Glass Co Electrically conducting coated glass or ceramic article suitable for use as a lens, a window or a windshield, or the like
US3020156A (en) * 1957-05-10 1962-02-06 Mycalex Corp Of America Method of coating metal on dielectric material
US3021233A (en) * 1959-05-22 1962-02-13 Honeywell Regulator Co Method of applying an electrically conductive contact material and resulting coated article
US3124478A (en) * 1959-07-21 1964-03-10 Ceramic

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1536749A (en) * 1919-12-03 1925-05-05 Ohio Brass Co Insulator
US2440691A (en) * 1945-03-07 1948-05-04 Continental Carbon Inc Alloy metal film resistor
US3010850A (en) * 1952-10-29 1961-11-28 Libbey Owens Ford Glass Co Electrically conducting coated glass or ceramic article suitable for use as a lens, a window or a windshield, or the like
US3020156A (en) * 1957-05-10 1962-02-06 Mycalex Corp Of America Method of coating metal on dielectric material
US3021233A (en) * 1959-05-22 1962-02-13 Honeywell Regulator Co Method of applying an electrically conductive contact material and resulting coated article
US3124478A (en) * 1959-07-21 1964-03-10 Ceramic

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4050956A (en) * 1970-02-20 1977-09-27 Commonwealth Scientific And Industrial Research Organization Chemical bonding of metals to ceramic materials
US5044406A (en) * 1987-03-18 1991-09-03 Semiconductor Energy Laboratory Co., Ltd. Pipe made from a superconducting ceramic material
US5474975A (en) * 1987-04-01 1995-12-12 Semiconductor Energy Laboratory Co., Ltd. Method for manufacturing an elongated member from a superconducting ceramic material
US5987731A (en) * 1987-04-01 1999-11-23 Semiconductor Energy Laboratory Co., Ltd. Elongated superconductive member
US5435889A (en) * 1988-11-29 1995-07-25 Chromalloy Gas Turbine Corporation Preparation and coating of composite surfaces
US4908740A (en) * 1989-02-09 1990-03-13 Hudgins Richard D Integral composite structure with predetermined electrically conductive networks and method for producing same
US20080233403A1 (en) * 2007-02-07 2008-09-25 Timothy Dyer Method of Making Ceramic Reactor Components and Ceramic Reactor Component Made Therefrom
US20090242271A1 (en) * 2008-03-28 2009-10-01 Jan Vetrovec Lightweight electric conductor assembly
US20110220285A1 (en) * 2010-02-12 2011-09-15 Morgan Advanced Ceramics, Inc. Methods and systems for texturing ceramic components

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