US2831242A - Sintered electric resistance heating element - Google Patents

Sintered electric resistance heating element Download PDF

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Publication number
US2831242A
US2831242A US344666A US34466653A US2831242A US 2831242 A US2831242 A US 2831242A US 344666 A US344666 A US 344666A US 34466653 A US34466653 A US 34466653A US 2831242 A US2831242 A US 2831242A
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Prior art keywords
molybdenum
oxide
silicon
aluminum
heating element
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US344666A
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Richard A Kieffer
Benesovsky Friedrich
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Schwarzkopf Technologies Corp
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Schwarzkopf Technologies Corp
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Priority to US344666A priority Critical patent/US2831242A/en
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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B3/00—Ohmic-resistance heating
    • H05B3/10—Heater elements characterised by the composition or nature of the materials or by the arrangement of the conductor
    • H05B3/12—Heater elements characterised by the composition or nature of the materials or by the arrangement of the conductor characterised by the composition or nature of the conductive material
    • H05B3/14—Heater elements characterised by the composition or nature of the materials or by the arrangement of the conductor characterised by the composition or nature of the conductive material the material being non-metallic
    • H05B3/148—Silicon, e.g. silicon carbide, magnesium silicide, heating transistors or diodes
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B2203/00—Aspects relating to Ohmic resistive heating covered by group H05B3/00
    • H05B2203/018—Heaters using heating elements comprising mosi2

Definitions

  • This invention relates to materials which exhibit strength and oxidation resistance at high temperatures and are particularly suited for resistor heating elements that can be operated without protective atmosphere and have a surprisingly high service life also in oxidizing atmospheres.
  • materials consisting of molybdenum, silicon and, if desired, further additions, meet these requirements.
  • a heating element ofthe outlined requirements may consist, for instance, of molybdenum silicides; and particularly advantageous are compositions of the ternary system, molybdenum-silicon-aluminum.
  • the heating element may be composed, for instance, of molybdenum silicides and molybdenum aluminides; or of molybdenum-silicon and molybdenum-aluminum alloys; or of a molybdenum, molybdenum-silicon or molybdenum-aluminum skeleton infiltrated with an aluminum-silicon alloy; or of molybdenum aluminide and silicon.
  • porous bodies of molybdenum or molybdenum-silicon or molybdenum-aluminum pre-alloys and to infiltrate these bodies with aluminum-silicon alloys.
  • Molybdenum-silicide of the composition MoSi is prepared, either by melting or by hot-pressing, and pulverized. After addition of a plasticizer, the silicide is extruded to form rods or tubes. The plasticizer is volatilized by heating and the compacts are then annealed (sintered) in a high-frequency furnace for 1-2 hours.
  • the sintered materials thus prepared have metallic conductivity, satisfactory strength and very high oxidation resistance.
  • a material on molybdenum silicide-molybdenum aluminide basis is prepared in the following manner: About 5% of molybdenum aluminide is added to molybdenum silicide. The mixture is compacted in the presence of a plasticizer. After volatilization of the plasticizer at red heat, the compact is presintered at 1100 C. and then subjected'to a final sintering process by direct passage of current through the compact in vacuum or in reducing or oxidizing atmosphere.
  • protective layers containing aluminum oxide is seen in the formation of compositions of mullite or sillimanite character.
  • the following example refers to the production of heating elements having a protective layer of this type.
  • the ends of the tube-shaped heating elements Prior to the final sintering operation, the ends of the tube-shaped heating elements are suitably inserted in terminal tubes of increased thickness; sintering then provides bonding between the terminals and the ends of the heatides which become conducting at high temperatures, such as zirconium oxide and thorium oxide, as well as with additions which are practically non-coductive at high temperatures, such as aluminum oxide, beryllium oxide and silicon oxide.
  • high temperatures such as zirconium oxide and thorium oxide
  • additions which are practically non-coductive at high temperatures such as aluminum oxide, beryllium oxide and silicon oxide.
  • the choice of the oxide to be added is dictated by the intended use of the elements.
  • a mixture of parts of molybdenum silicides, 10 parts of molybdenum aluminide and 30 parts of zirconium oxide is filled in a graphite die of cylindrical cross-section, the die than being introduced into a hot press where the charge is heated to 1400 C. under application of a pressure of l50200 kg./cm.
  • the die may be heated by a high-frequency field or by utilizing the graphite punches of the press for resistance heating.
  • the scope of the invention is not limited to molybdenum alloys;
  • the molybdenum may be partly replaced by other refractory metals such as tungsten, tantalum,
  • an elongated heater resistance body formed by sintering at an elevated temperature particles of its constituents, which constituents consist essentially of 60 to 70 parts by weight of molybdenum and silicon in proportions present in molybdenum disilicide, and 10 to 30 parts by weight of molybdenum and aluminum in proportions present in molybdenum aluminide (MoAl said constituents containing also up to 30% by weight of a refractory oxide selected from the group consisting of zirconium oxide, thorium oxide, aluminum oxide, beryllium oxide, silicon oxide, and mixtures of said oxides.
  • a heater device as claimed in claim 1 having a resistance body which consists essentially of about 70% of molybdenum and silicon in the proportions present in molybdenum disilicide and about 30% of aluminum and additional molybdenum in the proportions present in molybdenum aluminide (MoAl 3.

Description

SINTERED ELECTRIC RESISTANCE HEATING ELEMENT Richard A. Kielfer, Camillo Konopicky, and Friedrich Benesovsky, Reutte, Tirol, Austria, assignors to Schwarzkopf Development Corporation, a corporation of Maryland No Drawing. Application March 25, 1953 Serial No. 344,666
4 Claims. (Cl; 29-1825) This invention relates to materials which exhibit strength and oxidation resistance at high temperatures and are particularly suited for resistor heating elements that can be operated without protective atmosphere and have a surprisingly high service life also in oxidizing atmospheres.
According to the invention, materials consisting of molybdenum, silicon and, if desired, further additions, meet these requirements.
According to the invention, a heating element ofthe outlined requirements may consist, for instance, of molybdenum silicides; and particularly advantageous are compositions of the ternary system, molybdenum-silicon-aluminum. Accordingly, the heating element may be composed, for instance, of molybdenum silicides and molybdenum aluminides; or of molybdenum-silicon and molybdenum-aluminum alloys; or of a molybdenum, molybdenum-silicon or molybdenum-aluminum skeleton infiltrated with an aluminum-silicon alloy; or of molybdenum aluminide and silicon.
Heating elements, according to the invention, may be fabricated by any of the methods known to the art. It is thus possible to prepare heating elements in the form of tubes or loops by casting. It appears, however, preferable to prepare the elements by techniques of powder metallurgy; for instance, by extrusion followed by sintering and, if desired, under application of pressure during sintering.
It is also possible to prepare porous bodies of molybdenum or molybdenum-silicon or molybdenum-aluminum pre-alloys and to infiltrate these bodies with aluminum-silicon alloys.
The following examples will clarify the principle of the invention:
Molybdenum-silicide of the composition MoSi is prepared, either by melting or by hot-pressing, and pulverized. After addition of a plasticizer, the silicide is extruded to form rods or tubes. The plasticizer is volatilized by heating and the compacts are then annealed (sintered) in a high-frequency furnace for 1-2 hours. The sintered materials thus prepared have metallic conductivity, satisfactory strength and very high oxidation resistance.
A material on molybdenum silicide-molybdenum aluminide basis is prepared in the following manner: About 5% of molybdenum aluminide is added to molybdenum silicide. The mixture is compacted in the presence of a plasticizer. After volatilization of the plasticizer at red heat, the compact is presintered at 1100 C. and then subjected'to a final sintering process by direct passage of current through the compact in vacuum or in reducing or oxidizing atmosphere.
It is recommended to subject the heating element, prior to service, to a short-time treatment in an oxidizing at mosphere in order to form an adherent and gas-impervious protective layer. This is particularly recommended when the final sintering operation has been performed in a non-oxidizing atmosphere. After an insignificant volatilization of small amounts of molybdenum trioxide, this 2,831,242 Patented Apr. 22, 1958 V "ice ing from the aluminides as well as lower molybdenum oxides take part in the formation of the adherent protective layer.
The advantage of protective layers containing aluminum oxide is seen in the formation of compositions of mullite or sillimanite character. The following example refers to the production of heating elements having a protective layer of this type.
70 parts of molybdenum silicide and 30 parts of molybdenum aluminide of the approximate composition MoAl are mixed and hydrostatically compacted to the shape of tubes. The compacts are pre-heated, in carbon dioxide, at 1200 C., and finally sintered by direct passage of current at about 1600 C. (Throughout the specification and claims, all proportions are by weight, unless otherwise specifically stated.)
Prior to the final sintering operation, the ends of the tube-shaped heating elements are suitably inserted in terminal tubes of increased thickness; sintering then provides bonding between the terminals and the ends of the heatides which become conducting at high temperatures, such as zirconium oxide and thorium oxide, as well as with additions which are practically non-coductive at high temperatures, such as aluminum oxide, beryllium oxide and silicon oxide. The choice of the oxide to be added is dictated by the intended use of the elements.
The use of oxide additions is illustrated by the following example:
A mixture of parts of molybdenum silicides, 10 parts of molybdenum aluminide and 30 parts of zirconium oxide is filled in a graphite die of cylindrical cross-section, the die than being introduced into a hot press where the charge is heated to 1400 C. under application of a pressure of l50200 kg./cm. The die may be heated by a high-frequency field or by utilizing the graphite punches of the press for resistance heating. v
The scope of the invention is not limited to molybdenum alloys; The molybdenum may be partly replaced by other refractory metals such as tungsten, tantalum,
. niobium or chromium.
We claim:
1. In an electric heater device, an elongated heater resistance body formed by sintering at an elevated temperature particles of its constituents, which constituents consist essentially of 60 to 70 parts by weight of molybdenum and silicon in proportions present in molybdenum disilicide, and 10 to 30 parts by weight of molybdenum and aluminum in proportions present in molybdenum aluminide (MoAl said constituents containing also up to 30% by weight of a refractory oxide selected from the group consisting of zirconium oxide, thorium oxide, aluminum oxide, beryllium oxide, silicon oxide, and mixtures of said oxides.
2. In a heater device as claimed in claim 1, having a resistance body which consists essentially of about 70% of molybdenum and silicon in the proportions present in molybdenum disilicide and about 30% of aluminum and additional molybdenum in the proportions present in molybdenum aluminide (MoAl 3. Ina heater device as claimed in claim 1, having a resistance body which consists essentially of about 60% of molybdenum and silicon in the proportions found in Heany -2 Jan. 29, 1907 4 Linz July 21, Linz May 7, Stern Sept. 4, Goetzel et a1 Jan. 1, Briney Nov. 25, Beidler Jan. 12,
FOREIGN PATENTS Australia Aug. 10,
OTHER REFERENCES Mellor: Comprehensive Treatise on Inorganic and Theoretical Chemistry, vol. 11, page 523; pub. by Longmans, Green and Co., N. Y.

Claims (1)

1. IN AN ELECTRIC HEATER DEVICE, AN ELONGATED HEATER RESISTANCE BODY FORMED BY SINTERING AT AN ELEVATED TEMPERATURE PARTICLES OF ITS CONSTITUENTS, WHICH CONSTITUENTS CONSIST ESSENTIALLY OF 60 TO 70 PARTS BY WEIGHT OF MOLYBDENUM AND SILICON IN PROPORTIONS PRESENT IN MOLYBDENUM DISILICIDE, AND 10 TO 30 PARTS BY WEIGHT OF MOLYBEDENUM AND ALUMINUM IN PROPORTIONS PRESENT IN MOLYBEDENUM ALUMINIDE (MOAL5), SAID CONSTITUENTS CONTAINING ALSO UP TO 30% BY WEIGHT OF A REFRACTORY OXIDE SELECTED FROM THE GROUP CONSISTING OF ZIRCONIUM OXIDE, THORIUM OXIDE, ALUMINUM OXIDE, BERYLLIUM OXIDE, SILICON OXIDE, AND MIXTURES OF SAID OXIDES.
US344666A 1953-03-25 1953-03-25 Sintered electric resistance heating element Expired - Lifetime US2831242A (en)

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Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3297487A (en) * 1964-10-16 1967-01-10 Du Pont Fuel cell
US20100268206A1 (en) * 2009-04-17 2010-10-21 Kim Manwaring Method of treatment with multi-mode surgical tool
US8617151B2 (en) 2009-04-17 2013-12-31 Domain Surgical, Inc. System and method of controlling power delivery to a surgical instrument
US8858544B2 (en) 2011-05-16 2014-10-14 Domain Surgical, Inc. Surgical instrument guide
US8915909B2 (en) 2011-04-08 2014-12-23 Domain Surgical, Inc. Impedance matching circuit
US8932279B2 (en) 2011-04-08 2015-01-13 Domain Surgical, Inc. System and method for cooling of a heated surgical instrument and/or surgical site and treating tissue
US9078655B2 (en) 2009-04-17 2015-07-14 Domain Surgical, Inc. Heated balloon catheter
US9107666B2 (en) 2009-04-17 2015-08-18 Domain Surgical, Inc. Thermal resecting loop
US9131977B2 (en) 2009-04-17 2015-09-15 Domain Surgical, Inc. Layered ferromagnetic coated conductor thermal surgical tool
US9265556B2 (en) 2009-04-17 2016-02-23 Domain Surgical, Inc. Thermally adjustable surgical tool, balloon catheters and sculpting of biologic materials
US9526558B2 (en) 2011-09-13 2016-12-27 Domain Surgical, Inc. Sealing and/or cutting instrument
US10357306B2 (en) 2014-05-14 2019-07-23 Domain Surgical, Inc. Planar ferromagnetic coated surgical tip and method for making

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US842546A (en) * 1904-12-29 1907-01-29 John Allen Heany Manufacture of luminant for electric lamps.
US2290194A (en) * 1940-08-13 1942-07-21 Climax Molybdenum Co Process of producing molybdenum containing alloys
US2399747A (en) * 1943-10-11 1946-05-07 Climax Molybdenum Co Metallurgy
US2566752A (en) * 1948-10-14 1951-09-04 American Electro Metal Corp Method of producing a ferrous metal article infiltrated with a cuprous infiltrant
US2581252A (en) * 1947-12-31 1952-01-01 Sintercast Corp America Powder metallurgy articles
US2619406A (en) * 1949-04-27 1952-11-25 Union Carbide & Carbon Corp Method for the solid phase production of a disilicide
US2665474A (en) * 1950-03-18 1954-01-12 Fansteel Metallurgical Corp Highly refractory molybdenum alloys

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US842546A (en) * 1904-12-29 1907-01-29 John Allen Heany Manufacture of luminant for electric lamps.
US2290194A (en) * 1940-08-13 1942-07-21 Climax Molybdenum Co Process of producing molybdenum containing alloys
US2399747A (en) * 1943-10-11 1946-05-07 Climax Molybdenum Co Metallurgy
US2581252A (en) * 1947-12-31 1952-01-01 Sintercast Corp America Powder metallurgy articles
US2566752A (en) * 1948-10-14 1951-09-04 American Electro Metal Corp Method of producing a ferrous metal article infiltrated with a cuprous infiltrant
US2619406A (en) * 1949-04-27 1952-11-25 Union Carbide & Carbon Corp Method for the solid phase production of a disilicide
US2665474A (en) * 1950-03-18 1954-01-12 Fansteel Metallurgical Corp Highly refractory molybdenum alloys

Cited By (49)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3297487A (en) * 1964-10-16 1967-01-10 Du Pont Fuel cell
US9320560B2 (en) 2009-04-17 2016-04-26 Domain Surgical, Inc. Method for treating tissue with a ferromagnetic thermal surgical tool
US10405914B2 (en) 2009-04-17 2019-09-10 Domain Surgical, Inc. Thermally adjustable surgical system and method
US20100268216A1 (en) * 2009-04-17 2010-10-21 Kim Manwaring Inductively heated multi-mode ultrasonic surgical tool
US20100268209A1 (en) * 2009-04-17 2010-10-21 Kim Manwaring Inductively heated snare
US20100268212A1 (en) * 2009-04-17 2010-10-21 Kim Manwaring Method for inductively heating a surgical implement
US20100268213A1 (en) * 2009-04-17 2010-10-21 Kim Manwaring Inductively heated multi-mode surgical tool
US20100268208A1 (en) * 2009-04-17 2010-10-21 Kim Manwaring Surgical scalpel with inductively heated regions
US20100268214A1 (en) * 2009-04-17 2010-10-21 Kim Manwaring Surgical tool with inductively heated regions
US20100268205A1 (en) * 2009-04-17 2010-10-21 Kim Manwaring Method of treatment with adjustable ferromagnetic coated conductor thermal surgical tool
US20100268207A1 (en) * 2009-04-17 2010-10-21 Kim Manwaring Adjustable ferromagnetic coated conductor thermal surgical tool
US8292879B2 (en) 2009-04-17 2012-10-23 Domain Surgical, Inc. Method of treatment with adjustable ferromagnetic coated conductor thermal surgical tool
US8372066B2 (en) 2009-04-17 2013-02-12 Domain Surgical, Inc. Inductively heated multi-mode surgical tool
US8377052B2 (en) 2009-04-17 2013-02-19 Domain Surgical, Inc. Surgical tool with inductively heated regions
US8414569B2 (en) 2009-04-17 2013-04-09 Domain Surgical, Inc. Method of treatment with multi-mode surgical tool
US8617151B2 (en) 2009-04-17 2013-12-31 Domain Surgical, Inc. System and method of controlling power delivery to a surgical instrument
US8425503B2 (en) 2009-04-17 2013-04-23 Domain Surgical, Inc. Adjustable ferromagnetic coated conductor thermal surgical tool
US8430870B2 (en) 2009-04-17 2013-04-30 Domain Surgical, Inc. Inductively heated snare
US8491578B2 (en) 2009-04-17 2013-07-23 Domain Surgical, Inc. Inductively heated multi-mode bipolar surgical tool
US8506561B2 (en) 2009-04-17 2013-08-13 Domain Surgical, Inc. Catheter with inductively heated regions
US8523852B2 (en) 2009-04-17 2013-09-03 Domain Surgical, Inc. Thermally adjustable surgical tool system
US8523850B2 (en) 2009-04-17 2013-09-03 Domain Surgical, Inc. Method for heating a surgical implement
US8523851B2 (en) 2009-04-17 2013-09-03 Domain Surgical, Inc. Inductively heated multi-mode ultrasonic surgical tool
US8419724B2 (en) 2009-04-17 2013-04-16 Domain Surgical, Inc. Adjustable ferromagnetic coated conductor thermal surgical tool
US20100268210A1 (en) * 2009-04-17 2010-10-21 Kim Manwaring Inductively heated surgical implement driver
US9265553B2 (en) 2009-04-17 2016-02-23 Domain Surgical, Inc. Inductively heated multi-mode surgical tool
US11123127B2 (en) 2009-04-17 2021-09-21 Domain Surgical, Inc. System and method of controlling power delivery to a surgical instrument
US9078655B2 (en) 2009-04-17 2015-07-14 Domain Surgical, Inc. Heated balloon catheter
US9107666B2 (en) 2009-04-17 2015-08-18 Domain Surgical, Inc. Thermal resecting loop
US9131977B2 (en) 2009-04-17 2015-09-15 Domain Surgical, Inc. Layered ferromagnetic coated conductor thermal surgical tool
US10639089B2 (en) 2009-04-17 2020-05-05 Domain Surgical, Inc. Thermal surgical tool
US9220557B2 (en) 2009-04-17 2015-12-29 Domain Surgical, Inc. Thermal surgical tool
US9265555B2 (en) 2009-04-17 2016-02-23 Domain Surgical, Inc. Multi-mode surgical tool
US10441342B2 (en) 2009-04-17 2019-10-15 Domain Surgical, Inc. Multi-mode surgical tool
US9265554B2 (en) 2009-04-17 2016-02-23 Domain Surgical, Inc. Thermally adjustable surgical system and method
US9265556B2 (en) 2009-04-17 2016-02-23 Domain Surgical, Inc. Thermally adjustable surgical tool, balloon catheters and sculpting of biologic materials
US20100268206A1 (en) * 2009-04-17 2010-10-21 Kim Manwaring Method of treatment with multi-mode surgical tool
US10213247B2 (en) 2009-04-17 2019-02-26 Domain Surgical, Inc. Thermal resecting loop
US9549774B2 (en) 2009-04-17 2017-01-24 Domain Surgical, Inc. System and method of controlling power delivery to a surgical instrument
US9730749B2 (en) 2009-04-17 2017-08-15 Domain Surgical, Inc. Surgical scalpel with inductively heated regions
US10149712B2 (en) 2009-04-17 2018-12-11 Domain Surgical, Inc. Layered ferromagnetic coated conductor thermal surgical tool
US8915909B2 (en) 2011-04-08 2014-12-23 Domain Surgical, Inc. Impedance matching circuit
US9149321B2 (en) 2011-04-08 2015-10-06 Domain Surgical, Inc. System and method for cooling of a heated surgical instrument and/or surgical site and treating tissue
US8932279B2 (en) 2011-04-08 2015-01-13 Domain Surgical, Inc. System and method for cooling of a heated surgical instrument and/or surgical site and treating tissue
US8858544B2 (en) 2011-05-16 2014-10-14 Domain Surgical, Inc. Surgical instrument guide
US9526558B2 (en) 2011-09-13 2016-12-27 Domain Surgical, Inc. Sealing and/or cutting instrument
US11266459B2 (en) 2011-09-13 2022-03-08 Domain Surgical, Inc. Sealing and/or cutting instrument
US10357306B2 (en) 2014-05-14 2019-07-23 Domain Surgical, Inc. Planar ferromagnetic coated surgical tip and method for making
US11701160B2 (en) 2014-05-14 2023-07-18 Domain Surgical, Inc. Planar ferromagnetic coated surgical tip and method for making

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