GB2430670A - Method for preparing insulated particulate metals - Google Patents
Method for preparing insulated particulate metals Download PDFInfo
- Publication number
- GB2430670A GB2430670A GB0519942A GB0519942A GB2430670A GB 2430670 A GB2430670 A GB 2430670A GB 0519942 A GB0519942 A GB 0519942A GB 0519942 A GB0519942 A GB 0519942A GB 2430670 A GB2430670 A GB 2430670A
- Authority
- GB
- United Kingdom
- Prior art keywords
- particulate
- reactive material
- metal
- particulate metal
- agitating
- 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.)
- Withdrawn
Links
- 229910052751 metal Inorganic materials 0.000 title claims abstract description 94
- 239000002184 metal Substances 0.000 title claims abstract description 94
- 238000000034 method Methods 0.000 title claims abstract description 39
- 150000002739 metals Chemical class 0.000 title description 11
- 239000000463 material Substances 0.000 claims abstract description 87
- 150000001875 compounds Chemical class 0.000 claims abstract description 27
- 238000010438 heat treatment Methods 0.000 claims abstract description 24
- 239000000843 powder Substances 0.000 claims description 40
- 238000006243 chemical reaction Methods 0.000 claims description 17
- 239000002253 acid Substances 0.000 claims description 10
- 238000010521 absorption reaction Methods 0.000 claims description 7
- 150000003839 salts Chemical class 0.000 claims description 4
- 239000000203 mixture Substances 0.000 claims description 3
- 239000012080 ambient air Substances 0.000 claims description 2
- 150000007513 acids Chemical class 0.000 claims 1
- 230000005294 ferromagnetic effect Effects 0.000 abstract description 43
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 abstract description 10
- 229910052742 iron Inorganic materials 0.000 abstract description 5
- 150000003016 phosphoric acids Chemical class 0.000 abstract description 3
- VLAPMBHFAWRUQP-UHFFFAOYSA-L molybdic acid Chemical compound O[Mo](O)(=O)=O VLAPMBHFAWRUQP-UHFFFAOYSA-L 0.000 abstract description 2
- CMPGARWFYBADJI-UHFFFAOYSA-L tungstic acid Chemical compound O[W](O)(=O)=O CMPGARWFYBADJI-UHFFFAOYSA-L 0.000 abstract description 2
- WQEVDHBJGNOKKO-UHFFFAOYSA-K vanadic acid Chemical compound O[V](O)(O)=O WQEVDHBJGNOKKO-UHFFFAOYSA-K 0.000 abstract description 2
- 239000002245 particle Substances 0.000 description 51
- 230000005291 magnetic effect Effects 0.000 description 9
- 239000008358 core component Substances 0.000 description 5
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 4
- 239000003570 air Substances 0.000 description 3
- 239000011248 coating agent Substances 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- 239000002904 solvent Substances 0.000 description 3
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 239000002131 composite material Substances 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 239000011261 inert gas Substances 0.000 description 2
- WBJZTOZJJYAKHQ-UHFFFAOYSA-K iron(3+) phosphate Chemical class [Fe+3].[O-]P([O-])([O-])=O WBJZTOZJJYAKHQ-UHFFFAOYSA-K 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 238000003672 processing method Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 238000013019 agitation Methods 0.000 description 1
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 1
- 238000010292 electrical insulation Methods 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- 229910000398 iron phosphate Inorganic materials 0.000 description 1
- UOGMEBQRZBEZQT-UHFFFAOYSA-L manganese(2+);diacetate Chemical compound [Mn+2].CC([O-])=O.CC([O-])=O UOGMEBQRZBEZQT-UHFFFAOYSA-L 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G49/00—Compounds of iron
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
- B22F1/16—Metallic particles coated with a non-metal
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C24/00—Coating starting from inorganic powder
-
- 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
- H01F1/032—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 hard-magnetic materials
- H01F1/04—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 hard-magnetic materials metals or alloys
- H01F1/06—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 hard-magnetic materials metals or alloys in the form of particles, e.g. powder
- H01F1/061—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 hard-magnetic materials metals or alloys in the form of particles, e.g. powder with a protective layer
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Inorganic Chemistry (AREA)
- Powder Metallurgy (AREA)
- Soft Magnetic Materials (AREA)
Abstract
A method for preparing insulated particulate metal comprises providing a metal in particulate form, providing a reactive material in particulate form, and processing the particulate metal and the particulate reactive material in a manner such that the particulate reactive material reacts with the particulate metal to form a compound therewith capable of electrically insulating the particulate metal. The processing step may comprise mixing the particulate metal and the particulate reactive material and may comprise heating the particulate metal and the particulate reactive material. The metal may be iron or ferromagnetic, the reactive material may be dehydrated phosphoric acid, molybdic acid, tungstic acid or vanadic acid.
Description
I
Method for Preparing Insulated Particulate Metals The present invention relates to a method for preparing insulated particulate metals, and in particular to a method for preparing inorganically insulated particulate metals. The invention also relates to insulated particulate metals prepared in accordance with said method.
Insulated particulate metals, in which the particulate metal is magnetic, are well known and are used to fabricate magnetic core components for electrical converters and electrical machines such as motors.
Magnetic core components fabricated using insulated particulate : ** metals are required to demonstrate a number of characteristics in use, including low eddy current losses and low hysteresis losses, together known as core losses, and high magnetic permeability. Such fabricated magnetic * core components should also demonstrate good strength properties. S. S * .
Insulated particulate metals of this type are commonly known as dielectromagnetic materials or soft magnetic composites, and are prepared by e...20 wet processing methods in which the particulate metal is dispersed in a solution of a reactive material and a solvent. The solvent is subsequently evaporated resulting in a reaction between the particulate metal and the reactive material, and an electrically insulating compound is formed as a product of the reaction.
It would be desirable to provide an improved method for preparing insulated particulate metals.
According to a first aspect of the present invention, there is provided a method for preparing insulated particulate metal, the method comprising providing a metal in particulate form, providing a reactive material in particulate form, and processing the particulate metal and the particulate reactive material in a manner such that the particulate reactive material reacts with the particulate metal to form a compound therewith capable of electrically insulating the particulate metal.
The processing step may comprise agitating the particulate metal and the particulate reactive material. The agitating step preferably comprises mixing the particulate metal and the particulate reactive material.
Mixing of the particulate metal and the particulate reactive material ensures that the particulate reactive material may mix homogenously with the particulate metal and adhere to the surface of the particulate metal by forming a compound as a product of a reaction between the particulate metal and the * : particulate reactive material. SI.* * * **.*
Depending on the nature of the particulate reactive material and the reaction conditions, the reaction between the particulate metal and the particulate reactive material as a result of the agitating step may be insufficient to form a compound which provides a continuous insulating layer on the particles of the particulate metal. * 20
Under these circumstances, where substantial reaction does not occur between the particulate reactive material and the particulate metal as a result of the agitation step, the processing step may comprise heating the particulate metal and the particulate reactive material. The processing step may desirably comprise mixing the particulate metal and the particulate reactive material and thereafter heating the particulate metal and the particulate reactive material.
The heating step may result in the formation of a compound as a product of a reaction between the particulate metal and the particulate reactive material, said compound providing electrical insulation to the particulate metal. The compound may provide a substantially continuous electrically insulating layer on individual particles of the particulate metal.
The heating step may comprise heating the particulate reactive material and the particulate metal to a temperature up to approximately 300 C and may comprise maintaining the particulate reactive material and the particulate metal at this temperature for a predetermined time. The heating step may comprise heating the particulate reactive material and the particulate metal to a temperature of between approximately 175 C and approximately 300 C and may comprise heating to this temperature for a predetermined time of between 10 minutes and 120 minutes. The heating step may typically comprise heating the particulate reactive material and the particulate metal to a temperature of approximately 250 C for a predetermined time of approximately 30 minutes. * I. * . *
The step of agitating the particulate metal and particulate reactive material may cause friction therebetween which may grind and/or comminute * : the particulate reactive material.
S
S..... * .
The particulate metal may have a greater robustness than the particulate reactive material, and the step of agitating the particulate metal and particulate reactive material may grind and/or comminute the particulate reactive material.
The step of agitating the particulate metal and the particulate reactive material may be carried out at a temperature up to approximately 200 C and may be carried out at ambient temperature.
The particulate reactive material may be a hygroscopic material. The step of agitating the particulate metal and the particulate reactive material may promote the absorption of moisture by the particulate reactive material.
The absorption of moisture by the particulate reactive material may facilitate the reaction between the particulate reactive material and the particulate metal to form said compound.
The step of agitating the particulate metal and the particulate reactive material may promote the absorption of moisture by the particulate reactive material from atmosphere and/or from hydrated compounds, such as hydrated oxide compounds, on the particulate metal.
The reaction of the particulate reactive material with the particulate metal to form a compound may create an electrically insulating layer on individual particles of the particulate metal, the chemical nature of which may depend on the nature of the particulate reactive material and the particulate metal. Typically, the electrically insulating layer may comprise hydrated iron phosphates or hydrated iron molybdates or hydrated iron tungstates. * I* * * *
The step of agitating the particulate metal and the particulate reactive S...
material may be carried out in the presence of ambient air. The step of S. ..:. agitating the particulate metal and the particulate reactive material may : : alternatively be carried out in a substantially inert atmosphere, for example in the presence nitrogen or another substantially inert gas.
The particulate reactive material may comprise dehydrated acid powders such as phosphoric acid, molybdic acid, tungstic acid, vanadic acid, or their mixtures, compounds or salts. The particulate reactive material may comprise reactive acid salts of other metals, such as acetic acid manganese salt.
According to a second aspect of the present invention, there is provided insulated particulate metal prepared in accordance with the method of the first aspect of the present invention.
Embodiments of the present invention will now be described by way of
example only.
Particulate metal comprising a plurality of ferromagnetic particles is located in mixing apparatus which is capable of agitating the particles by mixing. Any suitable mixing apparatus, such as a cone blender, may be used.
The ferromagnetic particles may comprise pure iron or iron alloyed with other elements.
Particulate reactive material is also located in the mixing apparatus with the ferromagnetic particles. The particulate reactive material may comprise any suitable reactive material and is preferably in the form of a dehydrated acid powder such as acid crystals or their salts or compounds.
The reactive powder is a hygroscopic material capable of absorbing moisture. * I* * . S
After the ferromagnetic particles and the reactive powder have been 5..
located in the mixing apparatus, the mixing apparatus is activated to process S...
the ferromagnetic particles and the reactive powder by agitating and mixing them together. Desirably, the ferromagnetic particles and the reactive powder :. * are mixed together at normal ambient temperature using the mixing :...:. apparatus.
Due to the fact that the ferromagnetic particles have a greater robustness than individual particles of the reactive powder, friction and impact between the ferromagnetic particles and the reactive powder during mixing causes the particles of reactive powder to be comminuted by the ferromagnetic particles.
Comminution of the dry reactive powder in the mixing apparatus creates a significantly finer reactive powder in which the individual particles together present a much greater surface area. The individual finer particles of the reactive powder which are provided by the communiton step can, therefore, absorb moisture much more readily and to an extent which is sufficient to activate the reactive powder so that it reacts with the ferromagnetic particles to form a compound therewith, as a product of the reaction, which is capable of electrically insulating the ferromagnetic particles.
In one embodiment of the invention, the ferromagnetic particles and the reactive powder are mixed in the presence of air. In this case, the reactive powder is able to absorb moisture from the air and also from hydrated oxide compounds which may be present on the surface of the ferromagnetic particles. Mixing in the presence of air is preferred where the reactive powder has a low reactiveness with the ferromagnetic particles.
In an alternative embodiment of the invention, when a reactive powder which has a high reactiveness with the ferromagnetic particles is used, such * as dehydrated phosphoric acid powder, the mixing is desirably carried out in a substantially inert atmosphere, for example inside a chamber which has been I.,.
purged with nitrogen or an another substantially inert gas. In this case, the
I IS
reactive powder is only able to absorb moisture from hydrated oxide compounds on the surface of the ferromagnetic particles. The reaction between the reactive powder and the ferromagnetic particles therefore takes place more slowly.
When the dry reactive powder comprises dehydrated phosphoric acid powder, the acid powder, after absorbing moisture from the atmosphere and/or hydrated compounds on the surface of the ferromagnetic particles, reacts with individual ferromagnetic particles to form hydrated iron phosphate on the surfaces of the individual ferromagnetic particles. It will, however, be understood that the type of compound formed on the surfaces of the ferromagnetic particles will depend upon the form of the dry acid powder which is employed.
Depending upon the level of reactiveness of the reactive powder with the ferromagnetic particles, when it absorbs moisture as a result of mixing and contacts the surfaces of the ferromagnetic powder particles, it may adhere to and form a substantially continuous insulating layer on the individual ferromagnetic particles to electrically insulate those particles as a result of the reaction between the reactive powder and the ferromagnetic particles.
However, in cases where a less reactive powder is used, it is possible that the reactive powder may initially undergo very limited reaction with the individual ferromagnetic particles, resulting only in some adhesion between the reactive powder and the ferromagnetic particles at discrete locations on the surfaces of the ferromagnetic particles. Under these circumstances, the reaction may not be sufficient to form a continuous insulating layer on the surface of the individual ferromagnetic particles.
Accordingly, in order to provide a substantially continuous electrically insulating layer, which is necessary for the insulated particulate metal to function correctly when used to form a magnetic core component, it may be desirable to process the ferromagnetic particles and the reactive powder by heating them to a predetermined temperature and maintaining them at that predetermined temperature for a predetermined period of time. Heating to a
1 temperature of approximately 250 C for a period of approximately 30 minutes has been found to typically provide adequate results, although this depends on the nature of the reactive compound and of the ferromagnetic powder. ..DTD: During the heating step, it is believed that the semi-continuous coating of reactive compound formed on the surfaces of the ferromagnetic particles as a product of the reaction between the ferromagnetic particles and the reactive powder undergoes further, and more complete, reaction with the surfaces of the ferromagnetic particles, resulting in the formation of a continuous coating or layer of an electrically insulating compound on the surfaces of the ferromagnetic particles.
In addition, the reactive powder will typically comprise an amount of water chemically bound into the crystals thereof. Heating of the reactive powder is believed to liberate this chemically bound water and this is also believed to promote coating of substantially the entire surfaces of the ferromagnetic particles.
When the temperature is reduced at the end of the heating step, the resultant compound forms a substantially continuous electrically insulating layer on the surfaces of the individual ferromagnetic particles such that the individual ferromagnetic particles are each fully encapsulated by the electrically insulating layer.
Magnetic core components for electrical converters and machines may be fabricated by subjecting insulated particulate metals formed using the above method to appropriate compacting techniques usually carried out at :.: elevated temperatures. Suitable techniques are well known in the art. * SII
There is thus provided a method for preparing insulated particulate * metal which is offers advantages over known wet processing methods in which the particulate metal is dispersed in a solution of a reactive material and a solvent. As the method may be performed by simply agitating the * 20 ferromagnetic particles and the reactive powder, the method of the present invention makes it feasible for the end users of dielectromagnetic or soft magnetic composite materials to prepare the materials themselves in small quantities without the need for complex and expensive manufacturing equipment.
Although embodiments of the invention have been described in the preceding paragraphs with reference to various examples, it should be appreciated that various modifications to the examples given may be made without departing from the scope of the present invention, as claimed. For example, the particulate reactive material may comprise any suitable material which is capable of reacting with the ferromagnetic particles to form a compound therewith to electrically insulate the particles.
The ferromagnetic particles and the dry acid powder may be mixed together at a temperature of up to about 200 C in the mixing apparatus.
Any suitable apparatus capable of agitating the ferromagnetic particles and the dry acid powder to cause grinding and/or comminution of the dry acid powder may be employed.
Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance, it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings, whether or not particular emphasis has been placed thereon. I... S * S..,
S..... * . S. S
S S S * S... 5..
Claims (22)
- Claims 1. A method for preparing insulated particulate metal, the methodcomprising providing a metal in particulate form, providing a reactive material in particulate form, and processing the particulate metal and the particulate reactive material in a manner such that the particulate reactive material reacts with the particulate metal to form a compound therewith capable of electrically insulating the particulate metal.
- 2. A method according to claim 1, wherein the step of processing the particulate metal and the particulate reactive material comprises agitating the particulate metal and the particulate reactive material. * S..
- 3. A method according to claim 2, wherein the step of agitating the * ::: :115 particulate metal and the particulate reactive material comprises mixing the * : *** particulate metal and the particulate reactive material. ** S*
- 4. A method according to any of the preceding claims, wherein the step of I.e.processing the particulate metal and the particulate reactive material comprises heating the particulate metal and the particulate reactive material.
- 5. A method according to any of the preceding claims, wherein the step of processing the particulate metal and the particulate reactive material comprises mixing the particulate metal and the particulate reactive material and thereafter heating the particulate metal and the particulate reactive material.
- 6. A method according to claim 4 or claim 5, wherein the heating step comprises heating the particulate reactive material and the particulate metal to a temperature up to approximately 300 C and maintaining the particulate metal at this temperature for a predetermined time.
- 7. A method according to claim 6, wherein the heating step comprises heating the particulate reactive material and the particulate metal to a temperature of between approximately 175 C and approximately 300 C for a predetermined time of between 10 minutes and 120 minutes.
- 8. A method according to claim 7, wherein the heating step comprises heating the particulate reactive material and the particulate metal to a temperature of approximately 250 C for a predetermined time of approximately 30 minutes.
- 9. A method according to any of claims 2 to 8, wherein the step of agitating the particulate metal and the particulate reactive material : comminutes the particulate reactive material. S S*I*15
- 10. A method according to any of claims 2 to 9, wherein the step of * : * agitating the particulate metal and the particulate reactive material is carried out at ambient temperature. S...*
- 11. A method according to any of the preceding claims, wherein the particulate reactive material is a hygroscopic material.
- 12. A method according to any of claims 2 to 11, wherein the step of agitating the particulate metal and the particulate reactive material promotes the absorption of moisture by the particulate reactive material.
- 13. A method according to claim 12, wherein the absorption of moisture by the particulate reactive material facilitates a reaction between the particulate reactive material and the particulate metal.
- 14. A method according to claim 12 or claim 13, wherein the step of agitating the particulate metal and the particulate reactive material promotes the absorption of moisture by the particulate reactive material from atmosphere.
- 15. A method according to any of claims 12 to 14, wherein the step of agitating the particulate metal and the particulate reactive material promotes the absorption of moisture by the particulate reactive material from hydrated compounds on the particulate metal.
- 16. A method according to any of claims 2 to 15, wherein the step of agitating the particulate metal and the particulate reactive material is carried out in the presence of ambient air. * S.
- 17. A method according to any of claims 2 to 15, wherein the step of agitating the particulate metal and the particulate reactive material is carried 15 out in a substantially inert atmosphere.I..... * .
- 18. A method according to any of the preceding claims, wherein the * :.: particulate reactive material comprises powders of dehydrated acids or their * S.. mixtures, salts or compounds.
- 19. A method for preparing insulated particulate metal substantially as hereinbefore described.
- 20. Insulated particulate metal prepared in accordance with the method of any of the preceding claims.
- 21. Insulated particulate metal substantially as hereinbefore described.
- 22. Any novel subject matter or combination including novel subject matter disclosed herein, whether or not within the scope of or relating to the same invention as any of the preceding claims.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB0519942A GB2430670A (en) | 2005-09-30 | 2005-09-30 | Method for preparing insulated particulate metals |
| PCT/GB2005/003762 WO2007036679A1 (en) | 2005-09-30 | 2005-09-30 | Method for preparing insulated particulate metals |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB0519942A GB2430670A (en) | 2005-09-30 | 2005-09-30 | Method for preparing insulated particulate metals |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB0519942D0 GB0519942D0 (en) | 2005-11-09 |
| GB2430670A true GB2430670A (en) | 2007-04-04 |
Family
ID=35395055
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB0519942A Withdrawn GB2430670A (en) | 2005-09-30 | 2005-09-30 | Method for preparing insulated particulate metals |
Country Status (2)
| Country | Link |
|---|---|
| GB (1) | GB2430670A (en) |
| WO (1) | WO2007036679A1 (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB811935A (en) * | 1955-06-01 | 1959-04-15 | Gen Electric Co Ltd | Improvements in or relating to the manufacture of magnetizable powder cores |
| US5354488A (en) * | 1992-10-07 | 1994-10-11 | Trw Inc. | Fluid responsive to a magnetic field |
| EP0644253A2 (en) * | 1993-09-21 | 1995-03-22 | NIPPON OIL Co. Ltd. | Dispersion particles for fluid having magnetic and electrorheological effects simultaneously and fluid using the same |
| US6348265B1 (en) * | 1996-02-23 | 2002-02-19 | Höganäs Ab | Phosphate coated iron powder and method for the manufacturing thereof |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2602883B2 (en) * | 1988-03-11 | 1997-04-23 | 株式会社メイト | Surface treatment method for metal fine powder |
| US6372348B1 (en) * | 1998-11-23 | 2002-04-16 | Hoeganaes Corporation | Annealable insulated metal-based powder particles |
| US6713177B2 (en) * | 2000-06-21 | 2004-03-30 | Regents Of The University Of Colorado | Insulating and functionalizing fine metal-containing particles with conformal ultra-thin films |
| CA2452234A1 (en) * | 2002-12-26 | 2004-06-26 | Jfe Steel Corporation | Metal powder and powder magnetic core using the same |
-
2005
- 2005-09-30 GB GB0519942A patent/GB2430670A/en not_active Withdrawn
- 2005-09-30 WO PCT/GB2005/003762 patent/WO2007036679A1/en active Application Filing
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB811935A (en) * | 1955-06-01 | 1959-04-15 | Gen Electric Co Ltd | Improvements in or relating to the manufacture of magnetizable powder cores |
| US5354488A (en) * | 1992-10-07 | 1994-10-11 | Trw Inc. | Fluid responsive to a magnetic field |
| EP0644253A2 (en) * | 1993-09-21 | 1995-03-22 | NIPPON OIL Co. Ltd. | Dispersion particles for fluid having magnetic and electrorheological effects simultaneously and fluid using the same |
| US6348265B1 (en) * | 1996-02-23 | 2002-02-19 | Höganäs Ab | Phosphate coated iron powder and method for the manufacturing thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2007036679A1 (en) | 2007-04-05 |
| GB0519942D0 (en) | 2005-11-09 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |