WO1993011655A1 - Electromagnetic radiation susceptor material employing ferromagnetic amorphous alloy particles - Google Patents
Electromagnetic radiation susceptor material employing ferromagnetic amorphous alloy particles Download PDFInfo
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- WO1993011655A1 WO1993011655A1 PCT/US1992/006953 US9206953W WO9311655A1 WO 1993011655 A1 WO1993011655 A1 WO 1993011655A1 US 9206953 W US9206953 W US 9206953W WO 9311655 A1 WO9311655 A1 WO 9311655A1
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K9/00—Screening of apparatus or components against electric or magnetic fields
- H05K9/0073—Shielding materials
- H05K9/0081—Electromagnetic shielding materials, e.g. EMI, RFI shielding
- H05K9/0083—Electromagnetic shielding materials, e.g. EMI, RFI shielding comprising electro-conductive non-fibrous particles embedded in an electrically insulating supporting structure, e.g. powder, flakes, whiskers
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
- H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
- H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
- H01F1/12—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials
- H01F1/14—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys
- H01F1/147—Alloys characterised by their composition
- H01F1/153—Amorphous metallic alloys, e.g. glassy metals
- H01F1/15358—Making agglomerates therefrom, e.g. by pressing
- H01F1/15366—Making agglomerates therefrom, e.g. by pressing using a binder
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
- H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
- H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
- H01F1/12—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials
- H01F1/14—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys
- H01F1/147—Alloys characterised by their composition
- H01F1/153—Amorphous metallic alloys, e.g. glassy metals
- H01F1/15358—Making agglomerates therefrom, e.g. by pressing
- H01F1/15366—Making agglomerates therefrom, e.g. by pressing using a binder
- H01F1/15375—Making agglomerates therefrom, e.g. by pressing using a binder using polymers
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/25—Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
- Y10T428/256—Heavy metal or aluminum or compound thereof
Definitions
- This invention relates to electromagnetic radiation susceptor materials which comprise particles dispersed in dielectric binders.
- Electromagnetic radiation susceptor materials typically comprise one or more kinds of particles dispersed through a dielectric binder material. Incident radiation (typically in the GHz region of the spectrum) is converted into heat that is re-radiated by the susceptor to the surrounding environment. In this respect, susceptor materials differ from shielding materials, which reflect incident radiation with essentially no heating, and from absorbing materials, which attempt to completely frustrate the incident radiation by destructive interference.
- the invention is an electromagnetic radiation susceptor material, comprising at least one type of ferromagnetic amorphous alloy particle and a dielectric binder through which the particle(s) is (are) dispersed. Any of the dispersed particles comprises a ferromagnetic amorphous alloy having the composition F 100 . y .
- F is one or more magnetic element(s) selected from the group consisting of Fe, Co, and Ni
- M is one or more metaloid(s) selected from the group consisting of B, C, Al, Si, P, Ge and As
- TM is one or more transition metal(s) selected from columns IIIB (including the rare earths) to VIIB of the periodic table, especially Ti, V, Cr, Mn, Zr, Nb, and Ta; 0. ⁇ x ⁇ .20; and 10 y O.
- the transition metal component controls the Curie temperature of the alloy, and thus the magnetic response of the particles, providing self-regulation of temperature surrounding the susceptor material.
- the susceptor material of the invention comprises at least one species of ferromagnetic amorphous particle dispersed in a dielectric binder material. Typical volume loading factors range from one to 50 percent.
- any of the dispersed species of particles comprises ferromagnetic alloys having the composition F 100 . y . x M y TM x , where F is one or more magnetic elements selected from the group consisting of Fe, Co, and Ni; M is one or more metalo ⁇ ds selected from the group consisting of B, C, Al, Si, P, Ge and As; TM is one or more transition metal(s) selected from columns IIIB (including the rare earths) to VIIB of the periodic table, especially Ti, V, Cr, Mn, Zr, Nb, and Ta; 0- ⁇ x. ⁇ 20; and
- the transition metal component controls the Curie temperature of the alloy, typically permitting a choice of Curie temperature in the range of 50 to 400 C.
- the Curie temperature determines the temperature at which the magnetic susceptability of the ferromagnetic amorphous alloy particles goes to zero, thus ending the interaction with the incident electromagnetic radiation. This allows the susceptor to regulate temperature in a region adjacent the material as a function of time. This feature of the material is known as "self-regulation.”
- the Curie temperature should be chosen to be less than any temperature at which the properties of the dielectric binder change unacceptably, such as the melting point of the binder, or any temperature affecting the curing of polymeric components that may be present in the binder.
- the ferromagnetic amorphous alloys may be prepared by techniques involving rapid quenching, such as melt-spinning of a master alloy produced in an induction furnace.
- the preferred alloys contain at least 50% amorphous phase. Thermal annealing below the crystallization temperature improves the permeability, and thus the performance, of the alloys. Thirty minutes is a typical annealiing time.
- the ferromagnetic amorphous alloys are extremely resistant to oxidation and corrosion.
- the alloys may be reduced to smaller particles in any convenient manner, such as by grinding in an attritor or other high energy grinder, the preferred method uses a chromate treatment to prevent oxidation, as taught in European Patent Application 87307965.1.
- Other suitable methods include atomization, such as ultrasonic gas atomization or rotating disk, atomization.
- the particle size should be smaller than a fraction of the incident electromagnetic wavelength, but greater than several times the electromagnetic wave penetration depth (skin depth), which is also dependent upon incident radiation wavelength.
- skin depth For radiation in the range of 1-100 GHz (i.e., wavelengths on the order of centimeters), where penetration depths are typically on the order of ten to one-hundred micron, the typical particle size is 0.1 to 300 micron. Dispersion of the particles into the dielectric binder can be done by any convenient process, with mixing or extrusion being the most typical.
- the dielectric binder may be made from a ceramic, polymeric, or elastomeric material. Ceramic binders are preferred for applications requiring exposure to high temperatures, while polymeric binders are preferred for their flexibility and lightness. Many polymeric binders are suitable, including polyethylenes, polypropylenes, polymethyimethacrylates, urethanes, cellulose acetates, epoxies, and polytetrafluoroethylene (PTFE). Suitable elastomeric binders are natural rubbers and synthetic rubbers, such as the polychloroprene rubbers known by the tradename "NEOPRENE" and those based on ethylene propylene diene monomers (EPDM).
- NEOPRENE polychloroprene rubbers
- binders are silicone compounds available from General Electric Company under the designations RTV-1 1 and RTV-615.
- paper can serve as a suitable dielectric binder.
- the dielectric binder could be a made from thermosetting or thermoplastic material. Thermosetting materials, once heated, irreversibly cure and cannot be remelted non-destructively to be reformed. Thermoplastic materials can be repeatedly heated and reformed. In either case, the materials may be heated and set into a form by one or more forces external to the binder. Typically the force is due to heat conduction, or pressure, but it may be the influence of gravity or a vacuum.
- the binders suitable for the present invention differ from the "conformable" absorber materials taught in U.S.
- Patent 4,814,546 (Whitney et al.), which require molecular forces internal to the binder (such as a mechanical stress in a stretchable material) to be responsible for the change in shape of the absorber.
- Many types of adhesives have the required thermoplastic or thermosetting properties.
- An adhesive is a material which forms intimate contact with a surface such that mechanical force can be transferred across the contact interface.
- Suitable thermoplastic and thermosetting adhesives include (but are not limited to) polyamides, polyethylenes, polypropylenes, polymethyimethacrylates, urethanes, cellulose acetates, vinyl acetates, epoxies, and silicones.
- thermoplastic heat-shrinkable binder may be formed from cross-linked or oriented crystaliizable materials such as polyethylene, polypropylene, and polyvinyl chloride; or from amorphous materials such as silicones, polyacrylates, and polystyrenes.
- Solvent-shrinkable or mechanically stretchable binders may be elastomers such as natural rubbers or synthetic rubbers such as reactive diene polymers; suitable solvents are aromatic and aliphatic hydrocarbons. Specific examples of such materials are taught in U.S. Patent 4,814,546 (Whitney et al.).
- the binder may be homogenous, or a matrix of interentangled fibrils, such as the PTFE matrix taught in U.S. Patent 4,153,661 (Ree et al.).
- a susceptor in this embodiment is formed in a fibrillation process involving the formation of a water-logged paste of doubly layered particles and PTFE particles, intensive mixing at about 50° to about 100°C, biaxial calendering at about 50° to about 100°C, and drying at about 20° to about 100°C.
- the composite of PTFE fibrils and particles has the high tensile strength of the PTFE matrix.
- the invention is suitable for use in as broad an incident frequency range as possible in the radio frequency range (KHz to MHz) and the microwave region of approximately 2 to 40 GHz.
- the susceptor material should have a thickness in the direction of radiation propagation greater than about one-fourtieth (2.5 percent) of the incident wavelength.
- the 2-40 GHz range implies a thickness greater than the order of about 0.2 mm. Thicker layers generally provide improved performance, but the increased weight and reduced flexibility are not desired in many applications. Thus, while layers having thicknesses up to one-fourth (25 percent) of the incident wavelength are possible, they are not preferred. For example, in the same frequency region this upper thickness limit is on the order of about 37.5 mm, but sufficient absorption can be obtained with layers on the order of 2.0 mm or less in thickness.
- the susceptor material is non-electrically conductive, i.e., it has a high DC resistivity. If the resistivity is too low, the susceptor effectively becomes a conductive sheet, which reflects radiation instead of absorbing it.
- the resistivity of elemental iron for example, is about 10 "6 ohm-cm at room temperature.
- the resistivity of the ferromagnetic amorphous alloys used in this invention is not significantly higher, on the order of 1.5x10"* ohm-cm. Insulators typically have resistivities of tO 12 ohm-cm or more. However, the susceptor materials of the invention show measured resistivities greater than 10 B ohm-cm at room temperature, indicating that they are non-conductive.
- the susceptor material may be bound to any substrate, but especially to an electrically conductive material, by extruding the susceptor material onto the substrate and allowing the susceptor material to cure.
- Many thermoplastic binders are suitable for extrusion, especially polyvinylchlorides, polyamides, and polyurethanes.
- the substrate may be a wire or cable in iieu of a flat sheet.
- Alternatives to extrusion include the .use of adhesives, and processes involving in-place thermal casting.
- one lamina may be an susceptor comprising one species of ferromagnetic amorphous particle
- a second lamina may be a susceptor material comprising a second species
- a third lamina may be a susceptor material comprising yet a third species.
- Two to five layers are used in preferred embodiments.
- the total thickness of the laminated structure may be as great as 40 centimeters, although generally each lamina will meet the thickness limitations described above.
- Use of a laminated structure allows the absorption profile of the composite structure to be "tuned" to a particular frequency range and bandwidth of interest.
- the invention need not be in the form of a flat sheet.
- a pre-sized flexible cylindrical shell susceptor material is preferred to minimize possible stretching, cracking, or delamination of a flat laminated sheet.
- the pre-formed cylindrical shell could be slit along its length, wrapped around the conductor (or slid along the long axis of the conductor) with little distortion, and then adhered into place. The seam formed by the edges of the slit should be sealed.
- Example I Ferromagnetic amorphous alloys were manufactured in ribbon form with the composition Fe 73 B 10 Si ⁇ P 2 Cr 10 . They were tested for suitability for the invention by inductive heating, using a 10kW RF power supply (frequency 200-450 kHz) at three different power settings, 20%, 30% and 40%.
- the ribbon rapidly heated from room temperature (23 C) to about 45 C in 5 seconds, to about 53 C in 10 seconds, and to about 57 C in 15 seconds. However, after 25 seconds, the temperature was only about 60 C.
- 30% power the ribbon rapidly heated from room temperature to about 50 C in 5 seconds, to about 57 C in 10 seconds. However, after 15 seconds, the temperature was only about 60 C, and it increased only gradually to about 63 C in 35 seconds.
- Example II Two susceptor materials were constructed using RTV 615 silicon dielectric binders. Each susceptor material comprised ferromagnetic amorphous alloy particles of 325 mesh (44 micron) size manufactured as described above; one had the composition Fe 72 P 13 B 7 Cr 8 , the other had the composition Co ⁇ 7 B 16 Si ⁇ Mn ⁇ Nb 3 . The Curie temperatures of the particles were 190 C and 235 C respectively. The volume loading percentage in the RTV 615 binder was 20% for each susceptor material.
- a block of each material was heated in a common microwave oven.
- the iron-based alloy susceptor material showed rapid heating from room temperature to about 80 C in 50 seconds, and to about 125 C in 100 seconds; after that, to about 140 C in 50 seconds, and to about 150 C in 200 seconds; followed by slowly increasing heating to about 180 C after 550 seconds.
- the cobalt-based alloy susceptor material also showed rapid heating, to about 80 C after 50 seconds, and to about 140 C after 100 seconds; after that, slowly increasing heating to about 175 C at 225 seconds, and to about 200 C at 400 seconds.
- Example 111 A susceptor material comprising a ferromagentic amorphous alloy particles of 325 mesh (44 micron size) having a composition of Fe 72 P 13 B 7 Cr 8 dispersed into RTV 615 dielectric binder at a volume loading of 20% was subjected to standard microwave reflection and absorption measurements. The calculated imaginary part of the permeability as a function of frequency over the 0-10 GHz range agreed well with the theoretical model of absorption due to the gyromagnetic mechanism.
- Example IV Ferromagnetic amorphous alloy particles having the composition Fe 76 . 5 P 12 B ⁇ Cr B-E were produced by grinding an amorphous ribbon of the same composition to a powder of less than 325 mesh (44 micron) size. The particles had magnetization above 10 kG and Curie temperature of 215 C. The particles were dispersed in a PTFE membrane according to the process described above, at a particle loading of 20 volume percent. Three samples were made by calendering the membrane to thicknesses of 0.254 mm, 0.508 mm, and 0.559 mm. Microwave block heating tests showed rapid heating to about 120-160 C (depending on thickness) after 40 seconds, followed by constant heating at about 135-160 C in the 60-180 second period.
- Example V Ferromagnetic amorphous alloy particles of less than 200 mesh (70 micron) were dispersed into RTV 1 1 binder at a particle loading of 5 volume percent.
- Sample 1 had a composition of Fe 7 ⁇ . 6 P 12 B ⁇ Cr ⁇ 6 and a Curie temperature of about 215 C;
- Sample 2 had a composition of Fe 74 P.-B 8 Cr ⁇ and a Curie temperature of about 190 C;
- Sample 3 had a composition of Fe 7 ⁇ B 9 P ⁇ Si 3 Cr ⁇ and a Curie temperature of about 210 C.
- Block heating by RF induction (360 watts at 5-8 MHz) of Sample 1 showed rapid heating from room temperature to about 200 C in 10 seconds, and to about 225 C in 20 seconds, followed by constant heating at about 230 C from 30-90 seconds.
- Sample 2 showed rapid heating from room temperature to about 170 C in 10 seconds, and to about 180 C in 20 seconds, followed by slowly increasing heating to about 200 C at 55 seconds.
- Sample 3 showed rapid heating to about 180 C at 10 seconds, and to about 200 C at 20 seconds, followed by constant heating at about 200 C until 90 seconds.
- susceptors comprising stainless steel and mica particles heated at a rate of slightly less than 60 C per second, while those comprising nickel particles did so at about 55 C per second.
- susceptors comprising magnetite, at about 20 C per second; iron, about 15 C per second; stainless steel coated microbubbles at about 15 C per second; nickel-zinc ferrites at slightly less than 15 C per second; PM 3161 alloy at about 10 C per second; and carbonyl iron at about 2 C per second.
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Abstract
An electromagnetic radiation susceptor material comprises at least one species of particle dispersed in a dielectric binder material. Any dispersed species of particle comprises a ferromagnetic amorphous alloy having the composition F100-y-x?My?TMx?, where M is one or more magnetic elements selected from the group consisting of Fe, Co, and Ni; M is one or more metaloids selected from the group consisting of B, C, Al, Si, P and Ge; TM is one or more transition metal selected from the group consisting of columns IIIB (including the rare earths) to VIIB of the periodic table, and especially Ti, V, Cr, Mn, Zr, Nb, and Ta; 0x20; and 10y30. The transition metal controls the Curie temperature of the alloy to provide temperature self-regulation. Many types dielectric binder are suitable. The susceptor material may be applied to substrate, such as an electrically conductive material.
Description
ELECTROMAGNETIC RADIATION SUSCEPTOR MATERIAL EMPLOYING FERROMAGNETIC AMORPHOUS ALLOY PARTICLES
Technical Field This invention relates to electromagnetic radiation susceptor materials which comprise particles dispersed in dielectric binders.
Background
Electromagnetic radiation susceptor materials typically comprise one or more kinds of particles dispersed through a dielectric binder material. Incident radiation (typically in the GHz region of the spectrum) is converted into heat that is re-radiated by the susceptor to the surrounding environment. In this respect, susceptor materials differ from shielding materials, which reflect incident radiation with essentially no heating, and from absorbing materials, which attempt to completely frustrate the incident radiation by destructive interference.
Summary of Invention The invention is an electromagnetic radiation susceptor material, comprising at least one type of ferromagnetic amorphous alloy particle and a dielectric binder through which the particle(s) is (are) dispersed. Any of the dispersed particles comprises a ferromagnetic amorphous alloy having the composition F100.y.xMyTMx, where F is one or more magnetic element(s) selected from the group consisting of Fe, Co, and Ni; M is one or more metaloid(s) selected from the group consisting of B, C, Al, Si, P, Ge and As; TM is one or more transition metal(s) selected from columns IIIB (including the rare earths) to VIIB of the periodic table, especially Ti, V, Cr, Mn, Zr, Nb, and Ta; 0.<x <.20; and 10 y O.
The transition metal component controls the Curie temperature of the alloy, and thus the magnetic response of the particles, providing self-regulation of temperature surrounding the susceptor material.
Detailed Description The susceptor material of the invention comprises at least one species of ferromagnetic amorphous particle dispersed in a dielectric binder material. Typical volume loading factors range from one to 50 percent.
Any of the dispersed species of particles comprises ferromagnetic alloys having the composition F100.y.xMyTMx, where F is one or more magnetic
elements selected from the group consisting of Fe, Co, and Ni; M is one or more metaloϊds selected from the group consisting of B, C, Al, Si, P, Ge and As; TM is one or more transition metal(s) selected from columns IIIB (including the rare earths) to VIIB of the periodic table, especially Ti, V, Cr, Mn, Zr, Nb, and Ta; 0-<x.<20; and
The transition metal component controls the Curie temperature of the alloy, typically permitting a choice of Curie temperature in the range of 50 to 400 C. The Curie temperature determines the temperature at which the magnetic susceptability of the ferromagnetic amorphous alloy particles goes to zero, thus ending the interaction with the incident electromagnetic radiation. This allows the susceptor to regulate temperature in a region adjacent the material as a function of time. This feature of the material is known as "self-regulation." Of course, the Curie temperature should be chosen to be less than any temperature at which the properties of the dielectric binder change unacceptably, such as the melting point of the binder, or any temperature affecting the curing of polymeric components that may be present in the binder.
The ferromagnetic amorphous alloys may be prepared by techniques involving rapid quenching, such as melt-spinning of a master alloy produced in an induction furnace. The preferred alloys contain at least 50% amorphous phase. Thermal annealing below the crystallization temperature improves the permeability, and thus the performance, of the alloys. Thirty minutes is a typical annealiing time.
The ferromagnetic amorphous alloys are extremely resistant to oxidation and corrosion. However, while the alloys may be reduced to smaller particles in any convenient manner, such as by grinding in an attritor or other high energy grinder, the preferred method uses a chromate treatment to prevent oxidation, as taught in European Patent Application 87307965.1. Other suitable methods include atomization, such as ultrasonic gas atomization or rotating disk, atomization.
The particle size should be smaller than a fraction of the incident electromagnetic wavelength, but greater than several times the electromagnetic wave penetration depth (skin depth), which is also dependent upon incident radiation wavelength. For radiation in the range of 1-100 GHz (i.e., wavelengths on the order of centimeters), where penetration depths are typically on the order of ten to one-hundred micron, the typical particle size is 0.1 to 300 micron. Dispersion of the particles into the dielectric binder can be done by any convenient process, with mixing or extrusion being the most typical.
The dielectric binder may be made from a ceramic, polymeric, or elastomeric material. Ceramic binders are preferred for applications requiring
exposure to high temperatures, while polymeric binders are preferred for their flexibility and lightness. Many polymeric binders are suitable, including polyethylenes, polypropylenes, polymethyimethacrylates, urethanes, cellulose acetates, epoxies, and polytetrafluoroethylene (PTFE). Suitable elastomeric binders are natural rubbers and synthetic rubbers, such as the polychloroprene rubbers known by the tradename "NEOPRENE" and those based on ethylene propylene diene monomers (EPDM). Other preferred binders are silicone compounds available from General Electric Company under the designations RTV-1 1 and RTV-615. Also, paper can serve as a suitable dielectric binder. The dielectric binder could be a made from thermosetting or thermoplastic material. Thermosetting materials, once heated, irreversibly cure and cannot be remelted non-destructively to be reformed. Thermoplastic materials can be repeatedly heated and reformed. In either case, the materials may be heated and set into a form by one or more forces external to the binder. Typically the force is due to heat conduction, or pressure, but it may be the influence of gravity or a vacuum. In this respect the binders suitable for the present invention differ from the "conformable" absorber materials taught in U.S. Patent 4,814,546 (Whitney et al.), which require molecular forces internal to the binder (such as a mechanical stress in a stretchable material) to be responsible for the change in shape of the absorber. Many types of adhesives have the required thermoplastic or thermosetting properties. An adhesive is a material which forms intimate contact with a surface such that mechanical force can be transferred across the contact interface. Suitable thermoplastic and thermosetting adhesives include (but are not limited to) polyamides, polyethylenes, polypropylenes, polymethyimethacrylates, urethanes, cellulose acetates, vinyl acetates, epoxies, and silicones.
Alternatively, the conformable materials mentioned above are also suitable for other embodiments of the invention. For example, a thermoplastic heat-shrinkable binder may be formed from cross-linked or oriented crystaliizable materials such as polyethylene, polypropylene, and polyvinyl chloride; or from amorphous materials such as silicones, polyacrylates, and polystyrenes.
Solvent-shrinkable or mechanically stretchable binders may be elastomers such as natural rubbers or synthetic rubbers such as reactive diene polymers; suitable solvents are aromatic and aliphatic hydrocarbons. Specific examples of such materials are taught in U.S. Patent 4,814,546 (Whitney et al.). The binder may be homogenous, or a matrix of interentangled fibrils, such as the PTFE matrix taught in U.S. Patent 4,153,661 (Ree et al.). In general, a susceptor in this embodiment is formed in a fibrillation process involving the formation of a water-logged paste of doubly layered particles and PTFE particles,
intensive mixing at about 50° to about 100°C, biaxial calendering at about 50° to about 100°C, and drying at about 20° to about 100°C. The composite of PTFE fibrils and particles has the high tensile strength of the PTFE matrix.
The invention is suitable for use in as broad an incident frequency range as possible in the radio frequency range (KHz to MHz) and the microwave region of approximately 2 to 40 GHz.
To be effective in the microwave spectrum, the susceptor material should have a thickness in the direction of radiation propagation greater than about one-fourtieth (2.5 percent) of the incident wavelength. The 2-40 GHz range implies a thickness greater than the order of about 0.2 mm. Thicker layers generally provide improved performance, but the increased weight and reduced flexibility are not desired in many applications. Thus, while layers having thicknesses up to one-fourth (25 percent) of the incident wavelength are possible, they are not preferred. For example, in the same frequency region this upper thickness limit is on the order of about 37.5 mm, but sufficient absorption can be obtained with layers on the order of 2.0 mm or less in thickness.
The susceptor material is non-electrically conductive, i.e., it has a high DC resistivity. If the resistivity is too low, the susceptor effectively becomes a conductive sheet, which reflects radiation instead of absorbing it. The resistivity of elemental iron, for example, is about 10"6 ohm-cm at room temperature. The resistivity of the ferromagnetic amorphous alloys used in this invention is not significantly higher, on the order of 1.5x10"* ohm-cm. Insulators typically have resistivities of tO12 ohm-cm or more. However, the susceptor materials of the invention show measured resistivities greater than 10B ohm-cm at room temperature, indicating that they are non-conductive.
The susceptor material may be bound to any substrate, but especially to an electrically conductive material, by extruding the susceptor material onto the substrate and allowing the susceptor material to cure. Many thermoplastic binders are suitable for extrusion, especially polyvinylchlorides, polyamides, and polyurethanes. The substrate may be a wire or cable in iieu of a flat sheet. Alternatives to extrusion include the .use of adhesives, and processes involving in-place thermal casting.
Furthermore, a laminated structure, each lamina individually constructed according to the description above, is possible. For example, one lamina may be an susceptor comprising one species of ferromagnetic amorphous particle, a second lamina may be a susceptor material comprising a second species, and a third lamina may be a susceptor material comprising yet a third species. Two to five layers are used in preferred embodiments. The total thickness of the laminated
structure may be as great as 40 centimeters, although generally each lamina will meet the thickness limitations described above. Use of a laminated structure allows the absorption profile of the composite structure to be "tuned" to a particular frequency range and bandwidth of interest. The invention need not be in the form of a flat sheet. For a cylindrical conductor, for example, a pre-sized flexible cylindrical shell susceptor material is preferred to minimize possible stretching, cracking, or delamination of a flat laminated sheet. The pre-formed cylindrical shell could be slit along its length, wrapped around the conductor (or slid along the long axis of the conductor) with little distortion, and then adhered into place. The seam formed by the edges of the slit should be sealed.
Example I Ferromagnetic amorphous alloys were manufactured in ribbon form with the composition Fe73B10SiεP2Cr10. They were tested for suitability for the invention by inductive heating, using a 10kW RF power supply (frequency 200-450 kHz) at three different power settings, 20%, 30% and 40%. At 20% power, the ribbon rapidly heated from room temperature (23 C) to about 45 C in 5 seconds, to about 53 C in 10 seconds, and to about 57 C in 15 seconds. However, after 25 seconds, the temperature was only about 60 C. At 30% power, the ribbon rapidly heated from room temperature to about 50 C in 5 seconds, to about 57 C in 10 seconds. However, after 15 seconds, the temperature was only about 60 C, and it increased only gradually to about 63 C in 35 seconds. At 40% power, the ribbon heated at generally the same rate as at 30% power. The rapid heating followed by a constant temperature versus time profile indicates excellent temperature self-regulation of the ferromagnetic amorphous alloy.
Example II Two susceptor materials were constructed using RTV 615 silicon dielectric binders. Each susceptor material comprised ferromagnetic amorphous alloy particles of 325 mesh (44 micron) size manufactured as described above; one had the composition Fe72P13B7Cr8, the other had the composition Coβ7B16SiβMnβNb3. The Curie temperatures of the particles were 190 C and 235 C respectively. The volume loading percentage in the RTV 615 binder was 20% for each susceptor material.
A block of each material was heated in a common microwave oven. The iron-based alloy susceptor material showed rapid heating from room temperature to about 80 C in 50 seconds, and to about 125 C in 100 seconds; after that, to
about 140 C in 50 seconds, and to about 150 C in 200 seconds; followed by slowly increasing heating to about 180 C after 550 seconds. The cobalt-based alloy susceptor material also showed rapid heating, to about 80 C after 50 seconds, and to about 140 C after 100 seconds; after that, slowly increasing heating to about 175 C at 225 seconds, and to about 200 C at 400 seconds.
Example 111 A susceptor material comprising a ferromagentic amorphous alloy particles of 325 mesh (44 micron size) having a composition of Fe72P13B7Cr8 dispersed into RTV 615 dielectric binder at a volume loading of 20% was subjected to standard microwave reflection and absorption measurements. The calculated imaginary part of the permeability as a function of frequency over the 0-10 GHz range agreed well with the theoretical model of absorption due to the gyromagnetic mechanism.
Example IV Ferromagnetic amorphous alloy particles having the composition Fe76.5P12BβCrB-E were produced by grinding an amorphous ribbon of the same composition to a powder of less than 325 mesh (44 micron) size. The particles had magnetization above 10 kG and Curie temperature of 215 C. The particles were dispersed in a PTFE membrane according to the process described above, at a particle loading of 20 volume percent. Three samples were made by calendering the membrane to thicknesses of 0.254 mm, 0.508 mm, and 0.559 mm. Microwave block heating tests showed rapid heating to about 120-160 C (depending on thickness) after 40 seconds, followed by constant heating at about 135-160 C in the 60-180 second period.
Example V Ferromagnetic amorphous alloy particles of less than 200 mesh (70 micron) were dispersed into RTV 1 1 binder at a particle loading of 5 volume percent. Sample 1 had a composition of Fe7β.6P12BβCrε6 and a Curie temperature of about 215 C; Sample 2 had a composition of Fe74P.-B8Crβ and a Curie temperature of about 190 C; and Sample 3 had a composition of Fe7βB9PβSi3Crβ and a Curie temperature of about 210 C. Block heating by RF induction (360 watts at 5-8 MHz) of Sample 1 showed rapid heating from room temperature to about 200 C in 10 seconds, and to about 225 C in 20 seconds, followed by constant heating at about 230 C from 30-90 seconds. Sample 2 showed rapid heating from room temperature to about 170 C in 10 seconds, and to about 180 C in 20 seconds, followed by slowly
increasing heating to about 200 C at 55 seconds. Sample 3 showed rapid heating to about 180 C at 10 seconds, and to about 200 C at 20 seconds, followed by constant heating at about 200 C until 90 seconds.
These rapid heating rates, about 50 C per second, compare favorably to those of prior art materials at five volume percent loading in RTV 1 1 . For example, susceptors comprising stainless steel and mica particles heated at a rate of slightly less than 60 C per second, while those comprising nickel particles did so at about 55 C per second. Less suitable were susceptors comprising magnetite, at about 20 C per second; iron, about 15 C per second; stainless steel coated microbubbles at about 15 C per second; nickel-zinc ferrites at slightly less than 15 C per second; PM 3161 alloy at about 10 C per second; and carbonyl iron at about 2 C per second.
However, another sample of the invention comprising 40 micron particles at the same volume percentage showed a heating rate of about 90 C per second.
Claims
1. A electromagnetic radiation susceptor material, comprising at least one species of particle dispersed in a dielectric binder material, in which any dispersed species of particle comprises a ferromagnetic amorphous alloy having the composition F100.y.xMyTMx, where F is one or more magnetic elements selected from the group consisting of Fe, Co, and Ni; M is one or more metaloids selected from the group consisting of B, C, Al, Si, P, Ge and As; TM is one or more transition metal(s) selected from columns IIIB (including the rare earths) to VIIB of the periodic table; O. c.≤.20; and
10.<y<30.
2. The susceptor material of claim 1 in which TM is one or more transition metal(s) selected from the group consisting of Ti, V, Cr, Mn, Zr, Nb, and Ta.
3. The susceptor material of claim 1 in which the dielectric binder is ceramic.
4. The susceptor material of claim 1 in which the dielectric binder is polymeric.
5. The susceptor material of claim 4 in which the the polymeric binder comprises a polymer chosen from the group consisting of polyethylenes, polypropylenes, polymethyimethacrylates, urethanes, cellulose acetates, and polytetrafluoroethylene.
6. The susceptor material of claim 4 in which the polymeric binder comprises a polymer chosen from the group consisting of thermosetting polymeric adhesives and thermoplastic polymeric adhesives.
7. The susceptor material of claim 4 in which the polymeric binder comprises a polymer chosen from the group consisting of heat-shrinkable polymers, solvent-shrinkable polymers, and mechanically-stretchable polymers.
8. The susceptor material of claim 1 in which the dielectric binder is elastomeric.
9. The susceptor material of claim 1 in which any dispersed species of particle is dispersed in the dielectric binder at a volume loading between one and fifty percent.
10. The susceptor material of claim 1 as bound to a substrate.
*
5 1 1 . The susceptor material of claim 10 as bound to an electrically conductive substrate.
12. A laminated construction comprising two or more laminae of an electromagnetic radiation susceptor material, each lamina independentiy 10 meeting the limitations of claim 1 .
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP92918890A EP0614602A1 (en) | 1991-11-27 | 1992-08-21 | Electromagnetic radiation susceptor material employing ferromagnetic amorphous alloy particles |
JP5510074A JPH07501658A (en) | 1991-11-27 | 1992-08-21 | Electromagnetic radiation susceptor material using ferromagnetic amorphous alloy particles |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US800,632 | 1991-11-27 | ||
US07/800,632 US5278377A (en) | 1991-11-27 | 1991-11-27 | Electromagnetic radiation susceptor material employing ferromagnetic amorphous alloy particles |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1993011655A1 true WO1993011655A1 (en) | 1993-06-10 |
Family
ID=25178915
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US1992/006953 WO1993011655A1 (en) | 1991-11-27 | 1992-08-21 | Electromagnetic radiation susceptor material employing ferromagnetic amorphous alloy particles |
Country Status (6)
Country | Link |
---|---|
US (1) | US5278377A (en) |
EP (1) | EP0614602A1 (en) |
JP (1) | JPH07501658A (en) |
AU (1) | AU2514392A (en) |
TW (1) | TW273623B (en) |
WO (1) | WO1993011655A1 (en) |
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Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0239052A2 (en) * | 1986-03-24 | 1987-09-30 | Kabushiki Kaisha Riken | Magnetic-shielding material |
EP0301561A2 (en) * | 1987-07-31 | 1989-02-01 | TDK Corporation | Magnetic shield-forming magnetically soft powder, composition thereof, and process of making |
Family Cites Families (18)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2830162A (en) * | 1954-06-22 | 1958-04-08 | Raytheon Mfg Co | Heating method and apparatus |
GB1135803A (en) * | 1964-12-11 | 1968-12-04 | E M A Corp | Electromagnetic adhesive and method of joining materials thereby |
US3856513A (en) * | 1972-12-26 | 1974-12-24 | Allied Chem | Novel amorphous metals and amorphous metal articles |
US4144058A (en) * | 1974-09-12 | 1979-03-13 | Allied Chemical Corporation | Amorphous metal alloys composed of iron, nickel, phosphorus, boron and, optionally carbon |
US4153661A (en) * | 1977-08-25 | 1979-05-08 | Minnesota Mining And Manufacturing Company | Method of making polytetrafluoroethylene composite sheet |
US4371742A (en) * | 1977-12-20 | 1983-02-01 | Graham Magnetics, Inc. | EMI-Suppression from transmission lines |
JPS5644752A (en) * | 1979-09-21 | 1981-04-24 | Hitachi Ltd | Ferromagnetic amorphous alloy |
US4889568A (en) * | 1980-09-26 | 1989-12-26 | Allied-Signal Inc. | Amorphous alloys for electromagnetic devices cross reference to related applications |
US4409041A (en) * | 1980-09-26 | 1983-10-11 | Allied Corporation | Amorphous alloys for electromagnetic devices |
JPS6115941A (en) * | 1984-06-30 | 1986-01-24 | Res Dev Corp Of Japan | Ferromagnetic amorphous alloy containing oxygen and its manufacture |
US4719241A (en) * | 1985-12-20 | 1988-01-12 | Allied-Signal Inc. | Deionization sorbent comprised of ion exchange resin and polymer binder and ferromagnetic substance |
US4689163A (en) * | 1986-02-24 | 1987-08-25 | Matsushita Electric Industrial Co., Ltd. | Resin-bonded magnet comprising a specific type of ferromagnetic powder dispersed in a specific type of resin binder |
EP0260870A3 (en) * | 1986-09-12 | 1989-04-19 | Minnesota Mining And Manufacturing Company | Polymeric bonded metal magnet with corrosion resistant metal particles |
US4814546A (en) * | 1987-11-25 | 1989-03-21 | Minnesota Mining And Manufacturing Company | Electromagnetic radiation suppression cover |
WO1990003090A1 (en) * | 1988-09-09 | 1990-03-22 | Metcal, Inc. | Temperature auto-regulating, self-heating recoverable articles |
US5085931A (en) * | 1989-01-26 | 1992-02-04 | Minnesota Mining And Manufacturing Company | Microwave absorber employing acicular magnetic metallic filaments |
US5015993A (en) * | 1989-06-29 | 1991-05-14 | Pitney Bowes Inc. | Ferromagnetic alloys with high nickel content and high permeability |
US5032947A (en) * | 1989-07-12 | 1991-07-16 | James C. M. Li | Method of improving magnetic devices by applying AC or pulsed current |
-
1991
- 1991-11-27 US US07/800,632 patent/US5278377A/en not_active Expired - Fee Related
-
1992
- 1992-08-21 AU AU25143/92A patent/AU2514392A/en not_active Abandoned
- 1992-08-21 JP JP5510074A patent/JPH07501658A/en active Pending
- 1992-08-21 WO PCT/US1992/006953 patent/WO1993011655A1/en not_active Application Discontinuation
- 1992-08-21 EP EP92918890A patent/EP0614602A1/en not_active Withdrawn
- 1992-09-02 TW TW081106966A patent/TW273623B/zh active
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0239052A2 (en) * | 1986-03-24 | 1987-09-30 | Kabushiki Kaisha Riken | Magnetic-shielding material |
EP0301561A2 (en) * | 1987-07-31 | 1989-02-01 | TDK Corporation | Magnetic shield-forming magnetically soft powder, composition thereof, and process of making |
Non-Patent Citations (2)
Title |
---|
PATENT ABSTRACTS OF JAPAN vol. 11, no. 23 (E-473)(2470) 22 January 1987 * |
PATENT ABSTRACTS OF JAPAN vol. 9, no. 185 (E-332)(1908) 31 July 1985 * |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
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US5712044A (en) * | 1993-08-06 | 1998-01-27 | Minnesota Mining And Manufacturing Company | Medical device assemblies constructed from multilayered films |
US5766744A (en) * | 1993-08-06 | 1998-06-16 | Minnesota Mining And Manufacturing Company | Chlorine-free multilayered films |
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WO2001022464A1 (en) * | 1999-09-21 | 2001-03-29 | Sli Lichtsysteme Gmbh | Support material |
Also Published As
Publication number | Publication date |
---|---|
EP0614602A1 (en) | 1994-09-14 |
JPH07501658A (en) | 1995-02-16 |
AU2514392A (en) | 1993-06-28 |
US5278377A (en) | 1994-01-11 |
TW273623B (en) | 1996-04-01 |
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