US20090143216A1 - Composition and method - Google Patents
Composition and method Download PDFInfo
- Publication number
- US20090143216A1 US20090143216A1 US12/175,799 US17579908A US2009143216A1 US 20090143216 A1 US20090143216 A1 US 20090143216A1 US 17579908 A US17579908 A US 17579908A US 2009143216 A1 US2009143216 A1 US 2009143216A1
- Authority
- US
- United States
- Prior art keywords
- composition
- additive
- less
- grain boundary
- degrees celsius
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01C—RESISTORS
- H01C7/00—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material
- H01C7/10—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material voltage responsive, i.e. varistors
- H01C7/1006—Thick film varistors
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B18/00—Layered products essentially comprising ceramics, e.g. refractory products
-
- 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
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
- C04B35/453—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on zinc, tin, or bismuth oxides or solid solutions thereof with other oxides, e.g. zincates, stannates or bismuthates
-
- 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
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/626—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B
- C04B35/62605—Treating the starting powders individually or as mixtures
- C04B35/62685—Treating the starting powders individually or as mixtures characterised by the order of addition of constituents or additives
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01C—RESISTORS
- H01C17/00—Apparatus or processes specially adapted for manufacturing resistors
- H01C17/06—Apparatus or processes specially adapted for manufacturing resistors adapted for coating resistive material on a base
- H01C17/065—Apparatus or processes specially adapted for manufacturing resistors adapted for coating resistive material on a base by thick film techniques, e.g. serigraphy
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01C—RESISTORS
- H01C7/00—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material
- H01C7/18—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material comprising a plurality of layers stacked between terminals
-
- 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
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/3201—Alkali metal oxides or oxide-forming salts thereof
- C04B2235/3203—Lithium oxide or oxide-forming salts thereof
-
- 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
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/3205—Alkaline earth oxides or oxide forming salts thereof, e.g. beryllium oxide
- C04B2235/3206—Magnesium oxides or oxide-forming salts thereof
-
- 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
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/3205—Alkaline earth oxides or oxide forming salts thereof, e.g. beryllium oxide
- C04B2235/3208—Calcium oxide or oxide-forming salts thereof, e.g. lime
-
- 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
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/3217—Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina
-
- 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
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/3231—Refractory metal oxides, their mixed metal oxides, or oxide-forming salts thereof
- C04B2235/3241—Chromium oxides, chromates, or oxide-forming salts thereof
-
- 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
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/3262—Manganese oxides, manganates, rhenium oxides or oxide-forming salts thereof, e.g. MnO
-
- 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
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/3262—Manganese oxides, manganates, rhenium oxides or oxide-forming salts thereof, e.g. MnO
- C04B2235/3265—Mn2O3
-
- 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
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/327—Iron group oxides, their mixed metal oxides, or oxide-forming salts thereof
- C04B2235/3272—Iron oxides or oxide forming salts thereof, e.g. hematite, magnetite
-
- 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
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/327—Iron group oxides, their mixed metal oxides, or oxide-forming salts thereof
- C04B2235/3275—Cobalt oxides, cobaltates or cobaltites or oxide forming salts thereof, e.g. bismuth cobaltate, zinc cobaltite
-
- 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
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/327—Iron group oxides, their mixed metal oxides, or oxide-forming salts thereof
- C04B2235/3275—Cobalt oxides, cobaltates or cobaltites or oxide forming salts thereof, e.g. bismuth cobaltate, zinc cobaltite
- C04B2235/3277—Co3O4
-
- 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
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/327—Iron group oxides, their mixed metal oxides, or oxide-forming salts thereof
- C04B2235/3279—Nickel oxides, nickalates, or oxide-forming salts thereof
-
- 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
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/3284—Zinc oxides, zincates, cadmium oxides, cadmiates, mercury oxides, mercurates or oxide forming salts thereof
-
- 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
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/3293—Tin oxides, stannates or oxide forming salts thereof, e.g. indium tin oxide [ITO]
-
- 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
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/3294—Antimony oxides, antimonates, antimonites or oxide forming salts thereof, indium antimonate
-
- 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
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/3298—Bismuth oxides, bismuthates or oxide forming salts thereof, e.g. zinc bismuthate
-
- 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
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/34—Non-metal oxides, non-metal mixed oxides, or salts thereof that form the non-metal oxides upon heating, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/3418—Silicon oxide, silicic acids, or oxide forming salts thereof, e.g. silica sol, fused silica, silica fume, cristobalite, quartz or flint
-
- 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
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/60—Aspects relating to the preparation, properties or mechanical treatment of green bodies or pre-forms
- C04B2235/602—Making the green bodies or pre-forms by moulding
- C04B2235/6025—Tape casting, e.g. with a doctor blade
-
- 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
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/60—Aspects relating to the preparation, properties or mechanical treatment of green bodies or pre-forms
- C04B2235/606—Drying
-
- 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
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/65—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes
- C04B2235/656—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes characterised by specific heating conditions during heat treatment
-
- 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
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/65—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes
- C04B2235/656—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes characterised by specific heating conditions during heat treatment
- C04B2235/6562—Heating rate
-
- 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
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/65—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes
- C04B2235/656—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes characterised by specific heating conditions during heat treatment
- C04B2235/6567—Treatment time
-
- 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
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/65—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes
- C04B2235/66—Specific sintering techniques, e.g. centrifugal sintering
- C04B2235/668—Pressureless sintering
-
- 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
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/70—Aspects relating to sintered or melt-casted ceramic products
- C04B2235/74—Physical characteristics
- C04B2235/77—Density
-
- 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
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/70—Aspects relating to sintered or melt-casted ceramic products
- C04B2235/74—Physical characteristics
- C04B2235/78—Grain sizes and shapes, product microstructures, e.g. acicular grains, equiaxed grains, platelet-structures
- C04B2235/785—Submicron sized grains, i.e. from 0,1 to 1 micron
-
- 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
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/70—Aspects relating to sintered or melt-casted ceramic products
- C04B2235/80—Phases present in the sintered or melt-cast ceramic products other than the main phase
- C04B2235/85—Intergranular or grain boundary phases
-
- 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
- C04B2237/00—Aspects relating to ceramic laminates or to joining of ceramic articles with other articles by heating
- C04B2237/30—Composition of layers of ceramic laminates or of ceramic or metallic articles to be joined by heating, e.g. Si substrates
- C04B2237/32—Ceramic
- C04B2237/34—Oxidic
-
- 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
- C04B2237/00—Aspects relating to ceramic laminates or to joining of ceramic articles with other articles by heating
- C04B2237/50—Processing aspects relating to ceramic laminates or to the joining of ceramic articles with other articles by heating
- C04B2237/62—Forming laminates or joined articles comprising holes, channels or other types of openings
-
- 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
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
- Y10T29/49082—Resistor making
-
- 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
-
- 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
- Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
- Y10T428/2982—Particulate matter [e.g., sphere, flake, etc.]
- Y10T428/2991—Coated
Abstract
A composition includes a sintered mass having a plurality of cores and a grain boundary layer disposed between each of the plurality of cores. The core includes a transition metal oxide, and grain boundary layer includes a sintering additive, a grain growth inhibitor additive and a grain boundary additive.
Description
- This application is a non-provisional application that claims priority to provisional U.S. Pat. application Ser. No. 60/991,871, filed Dec. 3, 2007; the disclosure of which is hereby incorporated by reference.
- 1. Technical Field
- The invention includes embodiments that relate to a composition for use as a surge protector and/or varistor. The invention includes embodiments that relate to a method of using the composition, or derived device.
- 2. Discussion of Art
- A varistor is an electronic component with a non-ohmic current-voltage characteristic. Varistors may protect circuits against excessive transient voltages by incorporating them into the circuit in such a way that, when triggered, they will shunt the current created by the high voltage away from the sensitive components. A varistor may be known as Voltage Dependent Resistor or VDR.
- A type of varistor is the Metal Oxide Varistor (MOV). This contains a ceramic mass of zinc oxide grains, in a matrix of other metal oxides (such as small amounts of bismuth, cobalt, manganese) sandwiched between two metal plates (the electrodes). The boundary between each grain and its neighbour forms a diode junction, which allows current to flow in only one direction. The mass of randomly oriented grains is electrically equivalent to a network of back-to-back diode pairs, each pair in parallel with many other pairs. When a small or moderate voltage is applied across the electrodes, only a tiny current flows, caused by reverse leakage through the diode junctions. When a large voltage is applied, the diode junctions break down because of the avalanche effect, and a large current flows. The result of this behaviour is a highly nonlinear current-voltage characteristic, in which the MOV has a high resistance at low voltages and a low resistance at high voltages.
- A varistor remains non-conductive as a shunt mode device during normal operation when voltage remains well below its “clamping voltage”. If a transient pulse (often measured in joules) is too high, the device may melt, burn, vaporize, or otherwise be damaged or destroyed. This unacceptable (catastrophic) failure occurs when “Absolute Maximum Ratings” are exceeded. Varistor degradation is defined using curves that relate current, time, and number of transient pulses. A varistor fully degrades when its “clamping voltage” has changed by 10 percent. A fully-degraded varistor may remain functional, having no catastrophic failure, and may not be visually damaged.
- It may be desirable to have a composition or article with properties and characteristics that differ from those properties of currently available compositions and articles.
- In one embodiment, a composition is provided that includes a sintered mass having a plurality of cores and a grain boundary layer disposed between each of the plurality of cores. The core includes a transition metal oxide, and grain boundary layer includes a sintering additive and a grain growth inhibitor additive.
- In one embodiment, a composition is provided that includes a sintered reaction product of transition metal oxide particles that may have an average diameter less than about 1 micrometer; and sintering additive particles that may have an average diameter less than about 1 micrometer; and the grain growth inhibitor additive particles may have an average diameter less than about 1 micrometer.
- In one embodiment, a composition is provided. The composition includes a sintered mass of particles comprising a transition metal oxide, a sintering additive, and a grain growth inhibitor additive. The sintered mass may have a density greater than about 98 percent of theoretical density for a composition comprising the transition metal oxide.
- In one embodiment, a composition includes sintered particles that include a transition metal oxide, a sintering additive, a grain growth inhibitor additive and defining grains. The grains may have grain boundaries that define the grains to have an average grain size of less than about 0.8 micrometers.
-
FIG. 1 shows the electric field versus the current density (current voltage graph) for the composition in accordance with one embodiment of the invention and the comparative sample. -
FIG. 2 shows the SEM micrographs of the composition of the control blank. -
FIG. 3 shows the SEM micrographs of the composition in accordance with one embodiment of the invention. - The invention includes embodiments that relate to a composition for use as a surge protector and/or varistor. The invention includes embodiments that relate to a method of using the composition, or the derived device.
- As used herein, the term sintering is a method for making objects from particles or powder, by heating the material (below its melting point) until its particles adhere to each other. Sintered refers to particles or powder that has undergone a sintering process. A sintered mass refers to the formed shape that is the result of the sintering of powders or particulate. In the sintered mass, formerly discrete particles or powder grains retain a core, and the interstitial area from one core to another core is at least partially filled with a grain boundary layer that separates the cores.
- In one embodiment, a composition includes a sintered mass. The sintered mass includes a plurality of particle cores and a grain boundary layer disposed between each of the plurality of particle cores. Each of the cores may include a transition metal oxide. The grain boundary layer includes a sintering additive, a grain boundary additive, and/or a breakdown voltage additive.
- In one embodiment, the particle core may include a transition metal. In one embodiment, the transition metal may be a transition metal oxide. Examples of transition metal oxides include but are not limited to zinc oxide, tin oxide, and titanium oxide. In one embodiment, the transition metal oxide includes a zinc oxide. The amount of the transition metal oxide, by weight, may be greater than about 80 percent based on the total weight of the sintered mass. In one embodiment, the amount may be in a range of from about 80 weight percent to about 85 weight percent, from about 85 weight percent to about 90 weight percent, or from about 90 weight percent to about 95 weight percent or from about 95 weight percent to about 98 weight percent based on the total weight of the sintered mass.
- In one embodiment, the grain boundary layer is disposed between each of the plurality of the cores. The grain boundary layer includes a sintering additive. In one embodiment, the sintering additive may include one or more of aluminum, lithium, antimony, bismuth, cobalt, chromium, manganese, nickel, magnesium, or silicon. In one embodiment, the sintering additive may include a combination of two or more of the foregoing. In one embodiment, the sintering additive includes one or more of SiO2, Mn2O3, NiO, MnO2, MnCO3, Li2CO3, or LiBiO3. In one embodiment, the sintering additive may include one or more of Li2CO3, or LiBiO3. In one embodiment, the sintering additive may include a combination of two or more of the foregoing. The selection of the sintering additive may be based on one or more factors as the sintering additives differ in efficacy and effect. Such factors may include the desired sintering temperature, the sintering pressure, the material performance, and the desired grain characteristics.
- The sintering additive may be present in an amount that is less than about 15 percent by weight, based on the total weight of the sintered mass. In one embodiment, the sintering additive amount may be in a range of from about 15 percent to about 12 percent, from about 12 percent to about 10 percent, from about 10 percent to about 8 percent, from about 8 percent to about 4 percent, from about 4 percent to about 2 percent, from about 2 percent to about 0.5 percent, from about 0.5 percent to about 0.3 percent, or from about 0.3 percent to about 0.1 percent, or from about 0.1 percent to about 0.03 percent.
- In one embodiment, the grain boundary includes a grain growth inhibitor additive. In one embodiment, the grain growth inhibitor additive may include one or more of Sb2O3, CaO, Al2O3, MgO, or Fe2O3. In one embodiment, the grain growth inhibitor may consist essentially of only one of the foregoing. The selection of the grain growth inhibitor additive may be based on one or more factors as the grain growth inhibitor additive differ in efficacy and effect. Such factors may include the desired sintering temperature, the sintering pressure, the material performance, and the desired grain characteristics. In one embodiment, the grain growth inhibitor additive may inhibit grain growth to maintain relatively smaller grains. The grain growth inhibitor additive may control the grain size distribution, as well. In one embodiment, the grain growth inhibitor additive may be present in an amount in a range of from about 0.1 weight percent to about 0.5 weight percent, from about 0.5 weight percent to about 1.5 weight percent, or from about 1.5 weight percent to about 3 weight percent.
- In one embodiment, the grain growth inhibitor additive may include a combination of two or more of the foregoing. In one embodiment, the grain growth inhibitor additive may be present in the sintered mass in an amount, by weight, that is less than about 10 percent based on the total weight of the sintered mass. In one embodiment, the grain growth inhibitor additive amount may be in a range of from about 10 weight percent to about 8 weight percent, from about 8 weight percent to about 6 weight percent, 6 weight percent to about 4 weight percent, from about 4 weight percent to about 2 weight percent, from about 2 weight percent to about 1 weight percent, from about 1 weight percent to about 0.5 weight percent, from about 0.5 weight percent to about 0.1 weight percent, or less than about 0.1 weight percent.
- In one embodiment, the composition may further include a grain boundary additive. In one embodiment, the grain boundary additive includes a breakdown voltage additive. In one embodiment, the grain boundary additive may enhance the grain boundary barrier. In one embodiment, the grain boundary additive may include one or more of CO3O4, CO2O3, Cr2O3, Bi2O3, Pr2O3, NiO, or SnO2. In one embodiment, the grain boundary additive consists essentially of only one of the foregoing. The selection of the grain boundary additive may be based on one or more factors as the grain boundary additive differ in efficacy and effect. Such factors may include the desired sintering temperature, the sintering pressure, the material performance, and the desired grain characteristics. The grain boundary additive may be present in an amount less than about 1 weight percent. In one embodiment, the grain boundary additive may be present in an amount in a range of from about 0.01 weight percent to about 0.5 weight percent, from about 0.5 weight percent to about 0.75 weight percent, or from about 0.75 weight percent to about 1 weight percent. In one embodiment, the composition is free of CO2O3. In another embodiment, the amount of CO2O3 is less than about 0.05 weight percent.
- In one embodiment, the additive may include a combination of two or more of the foregoing. In one embodiment, the grain boundary additive may be present in the sintered mass in an amount, by weight, that is less than about 10 percent based on the total weight of the sintered mass. In one embodiment, the grain boundary additive is present in an amount in a range of from about 10 weight percent to about 8 weight percent, from about 8 weight percent to about 6 weight percent, from about 6 weight percent to about 4 weight percent, from about 4 weight percent to about 2 weight percent, from about 2 weight percent to about 1 weight percent, from about 1 weight percent to about 0.5 weight percent, from about 0.5 weight percent to about 0.1 weight percent, or less than about 0.1 weight percent.
- In one embodiment, the average distance from one core to an adjacent core in the plurality of cores is less than about 1 micrometer. In one embodiment, the average distance may be in a range of from about 1 micrometer to about 0.8 micrometers, or from about 0.8 micrometers to about 0.5 micrometers. In another embodiment, the average distance may be in a range of from about 500 nanometers to about 400 nanometers, from about 400 nanometers to about 300 nanometers, from about 300 nanometers to about 250 nanometers, from about 250 nanometers to about 200 nanometers, from about 200 nanometers to about 150 nanometers, from about 150 nanometers to about 100 nanometers, from about 100 nanometers to about 50 nanometers, or less than about 50 nanometers.
- In one embodiment, the average diameter of the core in the plurality of cores is less than about 1 micrometer. In one embodiment, the average diameter may be in a range of from about 1 micrometer to about 0.8 micrometers, or from about 0.8 micrometers to about 0.5 micrometers. In another embodiment, the average diameter may be in a range of from about 500 nanometers to about 400 nanometers, from about 400 nanometers to about 300 nanometers, from about 300 nanometers to about 250 nanometers, from about 250 nanometers to about 200 nanometers, from about 200 nanometers to about 150 nanometers, from about 150 nanometers to about 100 nanometers, from about 100 nanometers to about 50 nanometers, or less than about 50 nanometers.
- The micro-structure or nano-structure of the composition may be expressed in terms of an average distance from one core to an adjacent core in the sintered mass. The average distance from one core to an adjacent core in the sintered mass may be less than 5 micrometers. In one embodiment, the average distance may be in a range of from about 1 micrometer to about 0.8 micrometers, or from about 0.8 micrometers to about 0.5 micrometers. In another embodiment, the average distance may be in a range of from about 500 nanometers to about 400 nanometers, from about 400 nanometers to about 300 nanometers, from about 300 nanometers to about 250 nanometers, from about 250 nanometers to about 200 nanometers, from about 200 nanometers to about 150 nanometers, from about 150 nanometers to about 100 nanometers, from about 100 nanometers to about 50 nanometers, or less than about 50 nanometers. An exemplary core-to-core average distance may be in a range of from about 35 nanometers to about 75 nanometers.
- The distance of one core to another core, coupled with the core size, may affect the average thickness of the grain boundary layer. In one embodiment, the average thickness of the grain boundary layer may be less than about 1 micrometer. In another embodiment, the average thickness may be in a range of from about 1 micrometer to about 0.8 micrometers, or from about 0.8 micrometers to about 0.5 micrometers. In yet another embodiment, the average thickness may be in a range of from about 500 nanometers to about 400 nanometers, from about 400 nanometers to about 300 nanometers, from about 300 nanometers to about 250 nanometers, from about 250 nanometers to about 100 nanometers, from about 100 nanometers to about 50 nanometers, from about 50 nanometers to about 35 nanometers, from about 35 nanometers to about 20 nanometers, or less than about 20 nanometers.
- The grain boundary layer thickness, may be expressed as a mean value in nanometers. The mean value for the grain boundary layer may be less than about 50 nanometers. In one embodiment, the mean value may be in a range of from about 50 nanometers to about 10 nanometers, from about 10 nanometers to about 1 nanometer, or from about 1 nanometer to about 0.1 nanometers.
- In addition to such factors as the uniformity of core diameters, the uniformity of distribution of materials, and the uniformity of the grain boundary layer, the average distance of the cores from one to another may affect the performance, properties and characteristics of the varistor device made therefrom. Particularly, the diode junction performance, and the number of diode junctions per unit volume, may flow directly from the core spacing parameter.
- In one embodiment, the sintered mass may have a dielectric strength or breakdown field of greater than about 0.5 kV/mm. In one embodiment, the dielectric strength or breakdown field is in a range of from about 0.5 kV/mm to about 1 kV/mm, from about 1 kV/mm to about 1.5 kV/mm, from about 1.5 kV/mm to about 2 kV/mm, from about 2 kV/mm to about 2.5 kV/mm, from about 2.5 kV/mm to about 2.8 kV/mm, or greater than about 2.8 kV/mm. In one embodiment, the sintered mass may have a non-linearity coefficient (α) of greater than 25. In one embodiment, the non-linearity coefficient (α) may be in a range of from about 25 to about 50, from about 50 to about 75, from about 75 to about 100, from about 100 to about 125, from about 125 to about 140, or greater than about 140.
- The thermal profile may play a role in the melt temperature of the electrode of the MOV device. If the thermal profile is higher than the electrode melt temperature, then the electrode may be melted, damaged or destroyed. A higher thermal excursion during manufacture or sinter may then require an electrode with a corresponding melt temperature suitable for use after exposure to that temperature. Lower temperature capable electrode materials may be economically desirable, if the other performance parameters are correct. In addition, if the thermal profile shows a temperature excursion too high, the micro-structure or nano-structure may change and the sintered particles may melt and flow together rather than remain as a sintered mass. This may need to be balanced, as at least some heat is needed to get the particles to sinter in the first instance.
- In one embodiment, a sintered mass may be produced by mixing a transition metal oxide, a sintering additive, and a grain boundary additive under defined conditions to form a mixture. The mixture can be treated to a determined temperature profile. In one embodiment, the temperature profile includes exposure to a sinter temperature of less than about 1050 degrees Celsius. The composition may have a thermal profile also known as thermal history that may include exposure to a sintering temperature of not greater than about 1050 degrees Celsius. In one embodiment, the thermal profile includes exposure to a sinter temperature in a range of from about 1050 degrees Celsius to about 1000 degrees Celsius, from about 1000 degrees Celsius to about 950 degrees Celsius, from about 950 degrees Celsius to about 900 degrees Celsius, from about 900 degrees Celsius to about 875 degrees Celsius, or from about 875 degrees Celsius to about 850 degrees Celsius.
- In one embodiment, the composition includes a sintered reaction product of transition metal oxide particles that have an average diameter that is less than about 1 micrometer; and sintering additive particles having an average diameter that is less than about 1 micrometer. The grain growth inhibitor additive particles may have an average diameter that is less than about 1 micrometer. Due to the change in available surface area, and packing tendencies, particles of different sizes may form sintered masses having differing properties and characteristics.
- In one embodiment, the composition includes a sintered mass of particles that may include a transition metal oxide, a sintering additive, and a grain growth inhibitor additive. The sintered mass may have a density that is greater than 98 percent of theoretical density for a composition comprising the transition metal oxide.
- In one embodiment, the composition includes sintered particles that include a transition metal oxide, a sintering additive, and a grain growth inhibitor additive and defining grains. The grains may have grain boundaries that define the grains to have an average grain size of less than about 0.8 micrometers. In one embodiment, the method includes contacting a transition metal oxide, a sintering additive, and a grain growth inhibitor additive to form a mixture. The mixture may be treated to a temperature profile. In one embodiment, the temperature profile includes exposure to a sinter temperature of less than about 1050 degrees Celsius.
- The following examples illustrate methods and embodiments in accordance with the invention, and as such do not limit the claims. Unless specified otherwise, all ingredients may be commercially available from such common chemical suppliers as Alpha Aesar, Inc. (Ward Hill, Mass.), Sigma Aldrich (St. Louis, Mo.), Spectrum Chemical Mfg. Corp. (Gardena, Calif.), and the like.
- Examples 1 through 3 are prepared by mixing, calcining, ball milling, and sintering. The sintering is performed in a Uniaxial Press to make a puck for each sample that is about 1 inch in diameter. The various components and the weight percent for each of the components for examples 1 to 3 are given in Table 1.
- A mixture is formed from zinc oxide, and additives selected from cobalt, antimony, nickel, and chromium oxide nanopowders with bismuth, silicon, manganese oxide nanopowders in a ratio given in Table 1. The zinc oxide is commercially obtainable from Horsehead Coporation, (Monaca, Pa.). The additives are commercially obtainable from Nanostructured and Amorphous Materials Inc. (Houston, Tex.).
-
TABLE 1 Composition (Weight Sample Sample Sample Comparative Comparative percent) 1 2 3 Sample 1Sample 2 ZnO 94 85.5 94.69 83.39 92.21 Bi2O3 0.5 2 3 2.12 1.40 Sb2O3 1 3 1.5 6.34 3.75 Al2O3 — 2 0.01 0.04 — SiO2 2 3 — 0.43 0.07 Cr2O3 0.5 — — — 1.02 MnO — — — 0.9 0.4 Mn2O3 0.5 — 0.1 — — MgO — 2 — — — Fe2O3 — — — 0.01 0.04 Co2O3 — — — 1.13 1.17 Co3O4 0.5 2.5 0.5 — — NiO 1 — 0.2 1.27 — SnO2 — — — — 0.93 - The materials form a mixture in a mixed oxide wet process. The mixture is milled in a ball mill for about 6 hours in a ratio materials:ball:isopropyl alcohol=1:5:2 to form a slurry. The slurry is dried at 100 degrees Celsius. The dried powder is sieved and calcined at 550 degrees Celsius for about 2 hours in a Thermolyne 1400 furnace. The calcined powder is then ball milled for about 4 hours. The slurry formed is dried at 100 degrees Celsius and the dried powder is sieved. The powder is then pressed into pellets (thickness of about 1.5 millimeters) with a force of about 10000 pounds for about 1 minute. The pellet is sintered at temperatures from about 1000 degrees Celsius and 1050 degrees Celsius. The sintering is done in two different profiles including one and two steps in a Uniaxial Press for about 2 hours. The first profile is carried out at about at 1050 degrees Celsius at a heating rate of about 5 degrees Celsius per minute for about 2 hours and is allowed to cool. The second profile is carried out at about at 1000 degrees Celsius at a rate of about 10 degrees Celsius per minute for about 0.1 hours. Following this a second step sintering at a temperature of about 925 degrees Celsius to 975 degrees Celsius at a heating rate of about 10 degrees Celsius per minute is carried out for about 2 hours. The resultant product is
Sample 1, which has the compositional distribution as indicated in Table 1. - A mixture is formed from zinc oxide, and additives selected from oxide nanopowders cobalt, and antimony, with nanopowder oxides of bismuth, silicon, aluminum and magnesium in a ratio given in Table 1.
- The materials are mixed using a mixed Oxide Wet Process. The mixture is milled in a ball mill for about 6 hours in a ratio materials:ball:isopropyl alcohol=1:5:2 to form a slurry. The slurry is dried at 100 degrees Celsius. The dried powder is sieved and calcined at 550 degrees Celsius for about 2 hours in a Thermolyne 1400 furnace. The calcined powder is then ball milled for about 4 hours. The slurry formed is dried at 100 degrees Celsius and the dried powder is sieved. The powder is then pressed into pellets (thickness of about 1.5 millimeters) with a force of about 10000 pounds for about 1 minute. The pellet is sintered in a Uniaxial Press at different temperatures for about 2 hours at about 950 degrees Celsius, about 1050 degrees Celsius at a rate of about 5 degrees Celsius per minute. The resultant product is Sample 2, which has the compositional distribution indicated in Table 1.
- A mixture is formed from zinc oxide (from Horsehead Coporation, Monaca, Pa.), and additives selected from powders of cobalt, nickel, and antimony-based materials (from Nanostructured and Amorphous Materials Inc, Houston, Tex.), and with powders of bismuth, aluminum and manganese-based materials in amounts as given in Table 1.
- The materials are mixed using a mixed oxide wet process. The mixture is milled in a ball mill for about 6 hours in a ratio of powder materials:ball:isopropyl alcohol=1:5:2 to form a slurry. The slurry is dried at 100 degrees Celsius. The dried powder is sieved and calcined at 550 degrees Celsius for about 2 hours in a Thermolyne 1400 furnace. The calcined powder is then ball milled for about 4 hours. The slurry formed is dried at 100 degrees Celsius and the dried powder is sieved. The powder is then pressed into pellets (thickness of about 1.5 millimeters) with a force of about 10000 pounds for about 1 minute. The pellet is sintered in a pressureless mode at different temperatures for about 2 hours at about 850 degrees Celsius, about 900 degrees Celsius, about 950 degrees Celsius, about 1000 degrees Celsius and about 1050 degrees Celsius at a rate of about 5 degrees Celsius per minute. The resultant product is Sample 3, which has the compositional distribution indicated in Table 1.
- A 10 kiloOhm or 100 MegaOhm resistor is connected in parallel to the varistor and a voltage is applied. V1, the total voltage on sample and varistor is measured using a high voltage probe. V2, the voltage on the resistor is measured by a multimeter. V2 is used to calculate the current flowing through the varistor. V1-V2 is the voltage on the Samples 1-6. To measure I-V curve, at low voltage, a 100 MOhm resistor is used until the voltage on it is higher than about 100 Volts. A 10 kilo Ohm resistor is used to measure the I-V curve under high voltage (higher than about 100 Volts).
-
FIG. 1 shows the results of metal oxide varistor materials of Samples 1-3 relative to a commercially available metal oxide varistor material. The materials of Samples 1-3 display relatively better breakdown strength and relatively better nonlinearity compared toComparative Sample 1. The breakdown fields (electric fields when current density is 1 milliAmp per square centimeter) and nonlinearity coefficient α calculated are summarized in Table 2. - Table 2 shows that the metal oxide varistor materials of Samples 1-3 perform better after low temperature firing. For example, Sample 3 gives a breakdown field of greater than about 1700 volts per millimeter and a good nonlinearity coefficient (α) of about 77, but still has a low sintering temperature of 850 degrees Celsius.
-
TABLE 2 Breakdown fields and nonlinearity of metal oxide varistor materials of Samples 1-3 and commercially available metal oxide varistor material Sintering Breakdown Temperature (° C.)/ Field Nonlinearity Composition Time (Hours) (V/mm) coefficient α Sample 1 1000/2 1343 63 1050/2 972 138 Sample 2 950/2 2800 40 1000/2 2216 18 Sample 3 850/2 1710 77 900/2 546 19 950/2 515 77 1000/2 400 42 1050/2 315 79 Comparative NA 125 22 Sample 1 - Microstructure formation may depend at least in part on the sintering profile. Grain size is found to increase at higher sintering temperature.
FIGS. 2-3 compare the microstructure of a commercially available metal oxide varistor material Comparative Sample 1 (FIG. 2 ) with a metal oxide varistor material of Example 3 (FIG. 3 ). The average grain size of the metal oxide varistor materials of Sample 3 (sintered at 850 degrees Celsius) is less than 1 micrometer; and, this is in comparison to the commercially available metal oxide varistormaterial Comparative Sample 1 that has a grain size that is greater than 10 micrometers. Several phases may coexist in the metal oxide varistor materials of Samples 1-3. These phases may include the major conductive phase of less than 1 micrometer in size and one or more secondary phases located at the grain boundaries and in the grain boundary layer, which itself may include various dopants and sintering additives. - A mixture is formed from zinc oxide, and additives selected from oxide powders cobalt, and antimony, with powder oxides of bismuth, silicon, aluminum and chromium in amounts as given in Table 3. Unless otherwise indicated, the powders are nanoscale and have a narrow size distribution.
- The materials are mixed using a mixed Oxide Wet Process. The mixture is milled in a ball mill for about 6 hours in a ratio of ingredients:ball:isopropyl alcohol of 1:5:2 to form a slurry. The slurry is dried at 100 degrees Celsius. The dried powder is sieved and calcined at 550 degrees Celsius for about 2 hours in a THERMOLYNE 1400 furnace. The calcined powder is then ball milled for about 4 hours. The slurry formed is dried at 100 degrees Celsius and the dried powder is sieved. The powder is then pressed into pellets (thickness of about 1.5 millimeters) with a force of about 10000 pounds for about 1 minute. The pellet is sintered in a Uniaxial Press at different temperatures for about 2 hours at about 950 degrees Celsius, about 1050 degrees Celsius at a rate of about 5 degrees Celsius per minute. The resultant product is Sample 4, which has the compositional distribution indicated in Table 3.
- A plurality of mixtures are formed from zinc oxide, and additives selected from cobalt, antimony, nickel, and chromium-based powders with bismuth, silicon, manganese-based powders, each in an amount as given in Table 3. The powders, unless context or language indicates otherwise, are nano-scale and have an average diameter that is less than 100 nanometers, and a relatively narrow and mono-modal size distribution.
- The materials form a mixture in a mixed oxide wet process. The mixture is milled in a ball mill for about 6 hours in a ratio ingredients:ball:isopropyl alcohol of 1:5:2 to form a slurry. The slurry is dried at 100 degrees Celsius. The dried powder is sieved and calcined at 550 degrees Celsius for about 2 hours in a Thermolyne 1400 furnace. The calcined powder is then ball milled for about 4 hours. The slurry formed is dried at 100 degrees Celsius and the dried powder is sieved. The powder is then pressed into pellets (thickness of about 1.5 millimeters) with a force of about 10,000 pounds for about 1 minute. The pellet is sintered at temperatures from about 1000 degrees Celsius and 1050 degrees Celsius. The sintering is done in two different profiles including one and two steps in a Uniaxial Press for about 2 hours. The first profile is carried out at about at 1050 degrees Celsius at a heating rate of about 5 degrees Celsius per minute for about 2 hours and is allowed to cool. The second profile is carried out at about at 1000 degrees Celsius at a rate of about 10 degrees Celsius per minute for about 0.1 hours. Following, a second step includes sintering at a temperature of about 925 degrees Celsius to 975 degrees Celsius. The sintering is at a heating ramp up rate of about 10 degrees Celsius per minute for about 2 hours. The resultant product is Sample 5, which has the compositional distribution as indicated in Table 3.
- A mixture is formed from zinc oxide, and additives selected from powders of cobalt, lithium, nickel, and antimony-based materials, with powders of bismuth, and aluminum-based materials in amounts as given in Table 3.
- The materials are mixed using a mixed oxide wet process. The mixture is milled in a ball mill for about 6 hours in a ratio of powder ingredients:ball:isopropyl alcohol of 1:5:2 to form a slurry. The slurry is dried at 100 degrees Celsius. The dried powder is sieved and calcined at 550 degrees Celsius for about 2 hours in a THERMOLYNE 1400 furnace. The calcined powder is then ball milled for about 4 hours. The slurry formed is dried at 100 degrees Celsius and the dried powder is sieved. The powder is then pressed into a plurality of pellets (thickness of about 1.5 millimeters) with a force of about 10000 pounds for about 1 minute.
- The pellets are sintered in a pressureless mode at different temperatures for about 2 hours. The temperatures are: about 800 degrees Celsius (sample 6), about 850 degrees Celsius (sample 7), about 900 degrees Celsius (sample 8), about 950 degrees Celsius (sample 9), about 1000 degrees Celsius (sample 10), and about 1050 degrees Celsius (sample 11), each at a rate of about 5 degrees Celsius per minute. Sample 6 is subsequently subjected to each of the other temperature profiles. The resultant product pellets are represented in Samples 6-11, which have the compositional distribution indicated in Table 3. Additional samples 12 et seq. have the compositional makeup as indicated in Table 3, and are subject to the temperature profile of Sample 7 (850 degrees Celsius) and are prepared in the same manner as the rest of the Samples in the this example.
- Table 3 shows that the metal oxide varistor materials may perform relatively well, displaying a breakdown field of greater than about 1700 volts per millimeter and a good nonlinearity coefficient (α) of greater than about 75, but still having a relatively low sintering temperature.
-
TABLE 3 Composition Samples Sample Sample Sample (Wt percent) Sample 4 Sample 5 Sample 6 7-11 12 13 14 ZnO 85.5 94 94.69 94.69 95.0 84.0 94.0 Bi2O3 2 0.5 3 3 3.5 3 3 Sb2O3 3 1.4 1.5 1.5 0.2 3 0.1 Al2O3 3 — 0.01 0.01 0.1 — — SiO2 3 2 — — 0.1 0.5 1.0 Cr2O3 0.95 0.04 — — 0.1 — — MnO — — — — 0.1 0.5 — Mn2O3 — 0.6 — — 0.1 — — MgO 0.05 — — — 0.1 1 — Fe2O3 — — — — 0.1 0.5 — Co2O3 — — — — 0.1 2.5 — Co3O4 2.5 0.5 0.5 0.5 0.1 — — NiO — 0.96 0.2 0.2 0.1 3 — SnO2 — — — — 0.1 — — Li2CO3 — — 0.1 0.1 0.1 1.5 0.9 LiBiO3 — — — — 0.1 — 1 CaO — — — — 0.1 0.5 — Breakdown Field >1800 >1800 >1850 — — — — (V/mm) Nonlinearity >75 >80 >75 — — — — coefficient (α) - In the specification and claims, reference will be made to a number of terms have the following meanings. The singular forms “a”, “an” and “the” include plural referents unless the context clearly dictates otherwise. Approximating language, as used herein throughout the specification and claims, may be applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term such as “about” is not to be limited to the precise value specified. In some instances, the approximating language may correspond to the precision of an instrument for measuring the value. Similarly, “free” may be used in combination with a term, and may include an insubstantial number, or trace amounts, while still being considered free of the modified term.
- As used herein, the terms “may” and “may be” indicate a possibility of an occurrence within a set of circumstances; a possession of a specified property, characteristic or function; and/or qualify another verb by expressing one or more of an ability, capability, or possibility associated with the qualified verb. Accordingly, usage of “may” and “may be” indicates that a modified term is apparently appropriate, capable, or suitable for an indicated capacity, function, or usage, while taking into account that in some circumstances the modified term may sometimes not be appropriate, capable, or suitable. For example, in some circumstances an event or capacity can be expected, while in other circumstances the event or capacity cannot occur—this distinction is captured by the terms “may” and “may be”.
- Reactants and components referred to by chemical name or formula in the specification or claims hereof, whether referred to in the singular or plural, may be identified as they exist prior to coming into contact with another substance referred to by chemical name or chemical type (e.g., another reactant or a solvent). Preliminary and/or transitional chemical changes, transformations, or reactions, if any, that take place in the resulting mixture, solution, or reaction medium may be identified as intermediate species, master batches, and the like, and may have utility distinct from the utility of the reaction product or final material. Other subsequent changes, transformations, or reactions may result from bringing the specified reactants and/or components together under the conditions called for pursuant to this disclosure. In these, other subsequent changes, transformations, or reactions the reactants, ingredients, or the components to be brought together may identify or indicate the reaction product or final material.
- The embodiments described herein are examples of articles, compositions, and methods having elements corresponding to the elements of the invention recited in the claims. This written description may enable those of ordinary skill in the art to make and use embodiments having alternative elements that likewise correspond to the elements of the invention recited in the claims. The scope of the invention thus includes articles, compositions and methods that do not differ from the literal language of the claims, and further includes other articles, compositions and methods with insubstantial differences from the literal language of the claims. While only certain features and embodiments have been illustrated and described herein, many modifications and changes may occur to one of ordinary skill in the relevant art. The appended claims cover all such modifications and changes.
Claims (23)
1. A composition, comprising:
a sintered mass having a plurality of cores;
a grain boundary layer disposed between each of the plurality of cores; and
wherein the core comprises a transition metal oxide, and the grain boundary layer comprises a sintering additive and a grain growth inhibitor additive.
2. The composition as defined in claim 1 , wherein the transition metal oxide is zinc oxide.
3. The composition as defined in claim 1 , wherein the sintering additive comprises one or more material comprising lithium, antimony, bismuth, cobalt, manganese, or silicon.
4. The composition as defined in claim 3 , wherein the sintering additive is LiBiO3, Li2CO3, Mn2O3, MnO2, MnCO3, Sb2O5, or SiO2.
5. The composition as defined in claim 1 , wherein the amount of the transition metal oxide is greater than about 80 percent by weight, based on the total weight of the sintered mass.
6. The composition as defined in claim 1 , wherein the amount of the sintering additive is less than about 15 percent by weight, based on the total weight of the sintered mass.
7. The composition as defined in claim 1 , wherein the grain growth inhibitor additive comprises one or more of SiO2, Sb2O3, CaO, Al2O3, MgO, or Fe2O3.
8. The composition as defined in claim 1 , wherein the amount of the grain growth inhibitor additive is less than about 10 percent by weight, based on the total weight of the sintered mass.
9. The composition as defined in claim 1 , further comprising a grain boundary additive.
10. The composition as defined in claim 8 , wherein the grain boundary additive comprises CO3O4, Cr2O3, Bi2O3, Pr2O3, NiO, or SnO2.
11. The composition as defined in claim 8 , wherein the amount of the grain boundary additive is less than about 10 percent by weight, based on the total weight of the sintered mass.
12. The composition as defined in claim 1 , wherein the composition is substantially free of CO2O3.
13. The composition as defined in claim 1 , wherein an average distance from one core to an adjacent core in the plurality of cores is less than about 1 micrometer.
14. The composition as defined in claim 1 , wherein the average diameter of the cores is less than about 1 micrometer.
15. The composition as defined in claim 1 , wherein a mean value for the grain boundary layer is less than 50 nanometers.
16. The composition as defined in claim 1 , wherein an average distance from a grain boundary of one core to a grain boundary of an adjacent core in the sintered mass is less than about 1 micrometer.
17. The composition as defined in claim 1 , wherein the average thickness of the grain boundary layer is less than about 400 nanometer.
18. The composition as defined in claim 1 , wherein the sintered mass has a dielectric strength or breakdown field of greater than about 0.5 kV/mm.
19. The composition as defined in claim 1 , wherein the sintered mass has a non-linearity coefficient (α) of greater than about 25.
20. The composition as defined in claim 1 , wherein the sintered mass has a thermal profile comprising exposure to a sinter temperature of less than about 1050 degrees Celsius.
21. A composition comprising a sintered reaction product of:
transition metal oxide particles having an average diameter less than about 1 micrometer;
sintering additive particles having an average diameter less than about 1 micrometer; and
grain growth inhibitor additive particles having an average diameter less than about 1 micrometer, wherein the sintered reaction product has a thermal history that is less than about 1050 degrees Celsius.
22. A composition, comprising:
a sintered mass of particles comprising the reaction product of a transition metal oxide, a sintering additive, and a grain growth inhibitor additive; and, wherein the sintered mass has a density greater than about 98 percent of theoretical density for a composition comprising the transition metal oxide.
23. A composition, comprising:
sintered particles comprising a transition metal oxide, a sintering additive, and a grain growth inhibitor additive and defining grains; and
the grains have grain boundaries that define the grains to have an average grain size of less than about 0.8 micrometers.
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US12/175,799 US20090143216A1 (en) | 2007-12-03 | 2008-07-18 | Composition and method |
US12/340,795 US20090142590A1 (en) | 2007-12-03 | 2008-12-22 | Composition and method |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US99187107P | 2007-12-03 | 2007-12-03 | |
US12/175,799 US20090143216A1 (en) | 2007-12-03 | 2008-07-18 | Composition and method |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/340,795 Continuation-In-Part US20090142590A1 (en) | 2007-12-03 | 2008-12-22 | Composition and method |
Publications (1)
Publication Number | Publication Date |
---|---|
US20090143216A1 true US20090143216A1 (en) | 2009-06-04 |
Family
ID=40675109
Family Applications (4)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/175,799 Abandoned US20090143216A1 (en) | 2007-12-03 | 2008-07-18 | Composition and method |
US12/186,552 Abandoned US20090142217A1 (en) | 2007-12-03 | 2008-08-06 | Composition and method |
US12/204,013 Active 2031-03-26 US8207813B2 (en) | 2007-12-03 | 2008-09-04 | Electronic device and method |
US12/240,200 Active 2031-03-27 US8217751B2 (en) | 2007-12-03 | 2008-09-29 | Electronic device and method |
Family Applications After (3)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/186,552 Abandoned US20090142217A1 (en) | 2007-12-03 | 2008-08-06 | Composition and method |
US12/204,013 Active 2031-03-26 US8207813B2 (en) | 2007-12-03 | 2008-09-04 | Electronic device and method |
US12/240,200 Active 2031-03-27 US8217751B2 (en) | 2007-12-03 | 2008-09-29 | Electronic device and method |
Country Status (1)
Country | Link |
---|---|
US (4) | US20090143216A1 (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20110079755A1 (en) * | 2009-10-01 | 2011-04-07 | Abb Technology Ag | High field strength varistor material |
CN108341662A (en) * | 2018-04-17 | 2018-07-31 | 南京大学 | A kind of preparation method of low dielectric constant and low loss high-frequency ceramic baseplate material |
US20190148042A1 (en) * | 2017-11-10 | 2019-05-16 | Samsung Electro-Mechanics Co., Ltd. | Multilayer capacitor |
Families Citing this family (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20090143216A1 (en) * | 2007-12-03 | 2009-06-04 | General Electric Company | Composition and method |
JP6081051B2 (en) * | 2011-01-20 | 2017-02-15 | 太陽誘電株式会社 | Coil parts |
JP4906972B1 (en) | 2011-04-27 | 2012-03-28 | 太陽誘電株式会社 | Magnetic material and coil component using the same |
JP2012238841A (en) | 2011-04-27 | 2012-12-06 | Taiyo Yuden Co Ltd | Magnetic material and coil component |
JP5048155B1 (en) | 2011-08-05 | 2012-10-17 | 太陽誘電株式会社 | Multilayer inductor |
JP6012960B2 (en) | 2011-12-15 | 2016-10-25 | 太陽誘電株式会社 | Coil type electronic components |
CN111718192B (en) * | 2012-12-27 | 2023-07-21 | 东莞令特电子有限公司 | Varistor based on zinc oxide and method for manufacturing same |
RU2568444C1 (en) * | 2014-11-27 | 2015-11-20 | Федеральное государственное бюджетное учреждение науки Институт химии и технологии редких элементов и минерального сырья им. И.В. Тананаева Кольского научного центра Российской академии наук (ИХТРЭМС КНЦ РАН) | Zinc-oxide varistor ceramics |
JP6756484B2 (en) * | 2016-01-20 | 2020-09-16 | 株式会社日立製作所 | Voltage non-linear resistor |
CN105921744B (en) * | 2016-05-03 | 2018-05-11 | 广东智维立体成型科技有限公司 | A kind of metallic print inhibitor |
US10333374B2 (en) | 2017-05-08 | 2019-06-25 | General Electric Company | Resistively graded insulation for stators |
CN111386582A (en) * | 2018-10-12 | 2020-07-07 | 东莞令特电子有限公司 | Polymer piezoresistor |
Citations (26)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4495482A (en) * | 1981-08-24 | 1985-01-22 | General Electric Company | Metal oxide varistor with controllable breakdown voltage and capacitance and method of making |
US4681717A (en) * | 1986-02-19 | 1987-07-21 | The United States Of America As Represented By The United States Department Of Energy | Process for the chemical preparation of high-field ZnO varistors |
US4992333A (en) * | 1988-11-18 | 1991-02-12 | G&H Technology, Inc. | Electrical overstress pulse protection |
US4996510A (en) * | 1989-12-08 | 1991-02-26 | Raychem Corporation | Metal oxide varistors and methods therefor |
US5039452A (en) * | 1986-10-16 | 1991-08-13 | Raychem Corporation | Metal oxide varistors, precursor powder compositions and methods for preparing same |
US5268006A (en) * | 1989-03-15 | 1993-12-07 | Matsushita Electric Industrial Co., Ltd. | Ceramic capacitor with a grain boundary-insulated structure |
US5271969A (en) * | 1985-10-29 | 1993-12-21 | Atsushi Ogura | Method of manufacturing metal oxide ceramic composite powder |
US5369390A (en) * | 1993-03-23 | 1994-11-29 | Industrial Technology Research Institute | Multilayer ZnO varistor |
US5484766A (en) * | 1994-02-14 | 1996-01-16 | Electric Power Research Institute, Inc. | Preparation of Bi-Pb-Sr-Ca-Cu-O (2223) superconductors |
US5594406A (en) * | 1992-02-25 | 1997-01-14 | Matsushita Electric Industrial Co., Ltd. | Zinc oxide varistor and process for the production thereof |
US5952040A (en) * | 1996-10-11 | 1999-09-14 | Nanomaterials Research Corporation | Passive electronic components from nano-precision engineered materials |
US5973589A (en) * | 1997-06-23 | 1999-10-26 | National Science Council | Zno varistor of low-temperature sintering ability |
US6146552A (en) * | 1995-03-06 | 2000-11-14 | Matsushita Electric Industrial Co., Ltd. | Zinc oxide ceramics and method for producing the same |
US6184770B1 (en) * | 1998-04-07 | 2001-02-06 | Murata Manufacturing Co., Ltd. | Monolithic varistor |
US6373372B1 (en) * | 1997-11-24 | 2002-04-16 | General Electric Company | Current limiting device with conductive composite material and method of manufacturing the conductive composite material and the current limiting device |
US6444504B1 (en) * | 1997-11-10 | 2002-09-03 | Zoran Zivic | Multilayer ZnO polycrystallin diode |
US6620346B1 (en) * | 1997-08-13 | 2003-09-16 | Hydro-Quebec | Varistors based on nanocrystalline powders produced by mechanical grinding |
US6627100B2 (en) * | 2000-04-25 | 2003-09-30 | Kabushiki Kaisha Toshiba | Current/voltage non-linear resistor and sintered body therefor |
US20040015983A1 (en) * | 2002-04-22 | 2004-01-22 | Thomas Lemmons | Method and apparatus for a data receiver and controller for the facilitation of an enhanced television viewing environment |
US6913827B2 (en) * | 2000-06-21 | 2005-07-05 | The Regents Of The University Of Colorado | Nanocoated primary particles and method for their manufacture |
US7075404B2 (en) * | 2002-08-20 | 2006-07-11 | Murata Manufacturing Co., Ltd. | Porcelain composition for varistor and varistor |
US7085118B2 (en) * | 2003-04-10 | 2006-08-01 | Matsushita Electric Industrial Co., Ltd. | Electrostatic discharge protection component |
US7372357B2 (en) * | 2006-03-31 | 2008-05-13 | Tdk Corporation | Varistor body and varistor |
US7528088B2 (en) * | 2005-04-01 | 2009-05-05 | Tdk Corporation | Electronic device |
US20090142217A1 (en) * | 2007-12-03 | 2009-06-04 | General Electric Company | Composition and method |
US7649436B2 (en) * | 2006-03-31 | 2010-01-19 | Tdk Corporation | Varistor body and varistor |
Family Cites Families (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB9005990D0 (en) | 1990-03-16 | 1990-05-09 | Ecco Ltd | Varistor powder compositions |
US5973588A (en) | 1990-06-26 | 1999-10-26 | Ecco Limited | Multilayer varistor with pin receiving apertures |
US5153554A (en) | 1990-05-08 | 1992-10-06 | Raychem Corp. | Low voltage varistor array |
DE69529677T2 (en) | 1994-07-14 | 2004-03-25 | Surgx Corp., Fremont | PROTECTIVE STRUCTURES AGAINST CHANGEABLE VOLTAGE AND METHOD FOR PRODUCING THEM |
JP3251134B2 (en) | 1994-08-29 | 2002-01-28 | 松下電器産業株式会社 | Method for producing sintered zinc oxide |
US6290879B1 (en) | 1998-05-20 | 2001-09-18 | General Electric Company | Current limiting device and materials for a current limiting device |
US6351011B1 (en) | 1998-12-08 | 2002-02-26 | Littlefuse, Inc. | Protection of an integrated circuit with voltage variable materials |
DE60136243D1 (en) | 2000-04-26 | 2008-12-04 | Littlefuse Ireland Dev Company | Thermally protected varistor based on a metal oxide |
US7258819B2 (en) | 2001-10-11 | 2007-08-21 | Littelfuse, Inc. | Voltage variable substrate material |
US7132922B2 (en) | 2002-04-08 | 2006-11-07 | Littelfuse, Inc. | Direct application voltage variable material, components thereof and devices employing same |
JP2005203479A (en) | 2004-01-14 | 2005-07-28 | Matsushita Electric Ind Co Ltd | Static electricity countermeasure component |
US7279724B2 (en) | 2004-02-25 | 2007-10-09 | Philips Lumileds Lighting Company, Llc | Ceramic substrate for a light emitting diode where the substrate incorporates ESD protection |
US7167352B2 (en) | 2004-06-10 | 2007-01-23 | Tdk Corporation | Multilayer chip varistor |
KR100579136B1 (en) | 2004-12-16 | 2006-05-12 | 한국전자통신연구원 | Transformer for varying the inductance value |
-
2008
- 2008-07-18 US US12/175,799 patent/US20090143216A1/en not_active Abandoned
- 2008-08-06 US US12/186,552 patent/US20090142217A1/en not_active Abandoned
- 2008-09-04 US US12/204,013 patent/US8207813B2/en active Active
- 2008-09-29 US US12/240,200 patent/US8217751B2/en active Active
Patent Citations (27)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4495482A (en) * | 1981-08-24 | 1985-01-22 | General Electric Company | Metal oxide varistor with controllable breakdown voltage and capacitance and method of making |
US5271969A (en) * | 1985-10-29 | 1993-12-21 | Atsushi Ogura | Method of manufacturing metal oxide ceramic composite powder |
US4681717A (en) * | 1986-02-19 | 1987-07-21 | The United States Of America As Represented By The United States Department Of Energy | Process for the chemical preparation of high-field ZnO varistors |
US5039452A (en) * | 1986-10-16 | 1991-08-13 | Raychem Corporation | Metal oxide varistors, precursor powder compositions and methods for preparing same |
US4992333A (en) * | 1988-11-18 | 1991-02-12 | G&H Technology, Inc. | Electrical overstress pulse protection |
US5268006A (en) * | 1989-03-15 | 1993-12-07 | Matsushita Electric Industrial Co., Ltd. | Ceramic capacitor with a grain boundary-insulated structure |
US4996510A (en) * | 1989-12-08 | 1991-02-26 | Raychem Corporation | Metal oxide varistors and methods therefor |
US5594406A (en) * | 1992-02-25 | 1997-01-14 | Matsushita Electric Industrial Co., Ltd. | Zinc oxide varistor and process for the production thereof |
US5369390A (en) * | 1993-03-23 | 1994-11-29 | Industrial Technology Research Institute | Multilayer ZnO varistor |
US5484766A (en) * | 1994-02-14 | 1996-01-16 | Electric Power Research Institute, Inc. | Preparation of Bi-Pb-Sr-Ca-Cu-O (2223) superconductors |
US6146552A (en) * | 1995-03-06 | 2000-11-14 | Matsushita Electric Industrial Co., Ltd. | Zinc oxide ceramics and method for producing the same |
US5952040A (en) * | 1996-10-11 | 1999-09-14 | Nanomaterials Research Corporation | Passive electronic components from nano-precision engineered materials |
US5973589A (en) * | 1997-06-23 | 1999-10-26 | National Science Council | Zno varistor of low-temperature sintering ability |
US6620346B1 (en) * | 1997-08-13 | 2003-09-16 | Hydro-Quebec | Varistors based on nanocrystalline powders produced by mechanical grinding |
US6444504B1 (en) * | 1997-11-10 | 2002-09-03 | Zoran Zivic | Multilayer ZnO polycrystallin diode |
US6373372B1 (en) * | 1997-11-24 | 2002-04-16 | General Electric Company | Current limiting device with conductive composite material and method of manufacturing the conductive composite material and the current limiting device |
US6184770B1 (en) * | 1998-04-07 | 2001-02-06 | Murata Manufacturing Co., Ltd. | Monolithic varistor |
US6627100B2 (en) * | 2000-04-25 | 2003-09-30 | Kabushiki Kaisha Toshiba | Current/voltage non-linear resistor and sintered body therefor |
US6913827B2 (en) * | 2000-06-21 | 2005-07-05 | The Regents Of The University Of Colorado | Nanocoated primary particles and method for their manufacture |
US20040015983A1 (en) * | 2002-04-22 | 2004-01-22 | Thomas Lemmons | Method and apparatus for a data receiver and controller for the facilitation of an enhanced television viewing environment |
US7075404B2 (en) * | 2002-08-20 | 2006-07-11 | Murata Manufacturing Co., Ltd. | Porcelain composition for varistor and varistor |
US7085118B2 (en) * | 2003-04-10 | 2006-08-01 | Matsushita Electric Industrial Co., Ltd. | Electrostatic discharge protection component |
US7528088B2 (en) * | 2005-04-01 | 2009-05-05 | Tdk Corporation | Electronic device |
US7372357B2 (en) * | 2006-03-31 | 2008-05-13 | Tdk Corporation | Varistor body and varistor |
US7649436B2 (en) * | 2006-03-31 | 2010-01-19 | Tdk Corporation | Varistor body and varistor |
US20090142217A1 (en) * | 2007-12-03 | 2009-06-04 | General Electric Company | Composition and method |
US20090142580A1 (en) * | 2007-12-03 | 2009-06-04 | General Electric Company | Electronic device and method |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20110079755A1 (en) * | 2009-10-01 | 2011-04-07 | Abb Technology Ag | High field strength varistor material |
US9672964B2 (en) * | 2009-10-01 | 2017-06-06 | Abb Schweiz Ag | High field strength varistor material |
US20190148042A1 (en) * | 2017-11-10 | 2019-05-16 | Samsung Electro-Mechanics Co., Ltd. | Multilayer capacitor |
CN109767917A (en) * | 2017-11-10 | 2019-05-17 | 三星电机株式会社 | Multi-layer capacitor and dielectric combination |
KR20190053480A (en) * | 2017-11-10 | 2019-05-20 | 삼성전기주식회사 | Multi-layered capacitor |
US10854363B2 (en) * | 2017-11-10 | 2020-12-01 | Samsung Electro-Mechanics Co., Ltd. | Multilayer capacitor |
KR102579634B1 (en) * | 2017-11-10 | 2023-09-18 | 삼성전기주식회사 | Multi-layered capacitor |
CN108341662A (en) * | 2018-04-17 | 2018-07-31 | 南京大学 | A kind of preparation method of low dielectric constant and low loss high-frequency ceramic baseplate material |
Also Published As
Publication number | Publication date |
---|---|
US20090140833A1 (en) | 2009-06-04 |
US8217751B2 (en) | 2012-07-10 |
US8207813B2 (en) | 2012-06-26 |
US20090142580A1 (en) | 2009-06-04 |
US20090142217A1 (en) | 2009-06-04 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US20090143216A1 (en) | Composition and method | |
TWI512024B (en) | Composition having non-linear current-voltage characteristics | |
Nahm | The electrical properties and dc degradation characteristics of Dy2O3 doped Pr6O11-based ZnO varistors | |
KR20010022821A (en) | Varistors based on nanocrystalline powders produced by mechanical grinding | |
CN111718192B (en) | Varistor based on zinc oxide and method for manufacturing same | |
He et al. | ZnO varistors with high voltage gradient and low leakage current by doping rare-earth oxide | |
US20090142590A1 (en) | Composition and method | |
JP2023179653A (en) | Varistor for high-temperature applications | |
Bouchekhlal et al. | Effect of sintering temperature on microstructure and nonlinear electrical characteristics of ZnO varistor | |
JP6628812B2 (en) | Manufacturing method of large capacity ZnO varistor | |
Nahm | The effect of sintering temperature on electrical properties and accelerated aging behavior of PCCL-doped ZnO varistors | |
Nahm | Preparation and varistor properties of new quaternary Zn–V–Mn–(La, Dy) ceramics | |
EP3819921B1 (en) | Zinc oxide varistor ceramics | |
JP4184172B2 (en) | Voltage nonlinear resistor ceramic composition, electronic component and multilayer chip varistor | |
US20100157492A1 (en) | Electronic device and associated method | |
CN106946564B (en) | Linear resistance material and preparation method thereof | |
JP2546726B2 (en) | Voltage nonlinear resistor | |
JP2006245111A (en) | Bismuth-based zinc oxide varistor | |
JP2001093705A (en) | Nonlinear resistor and method for manufacture thereof | |
KR20200074879A (en) | ZnO-BASED VARISTOR COMPOSITION AND METHOD OF MANUFACTURING THE SAME AND VARISTOR USING THE SAME | |
KR20200074882A (en) | ZnO-BASED VARISTOR COMPOSITION AND METHOD OF MANUFACTURING THE SAME AND VARISTOR USING THE SAME | |
de Melo Furtado et al. | MICROSTRUCTURAL ASPECTS AND ELECTROTHERMAL BEHAVIOR OF VARISTOR CERAMICS | |
JP2003264104A (en) | Manufacturing method of voltage non-linear resistor, voltage non-linear resistor element using this voltage non-linear resistor manufactured by this method, and lightning arrester using this voltage non-linear resistor element | |
JPH03195003A (en) | Voltage-dependent nonlinear resistor | |
JPH0128483B2 (en) |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: GENERAL ELECTRIC COMPANY, NEW YORK Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:TAN, DANIEL QI;IRWIN, PATRICIA CHAPMAN;YOUNSI, ABDELKRIM;AND OTHERS;REEL/FRAME:021258/0627;SIGNING DATES FROM 20080701 TO 20080715 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |