Powdered ferromagnetic composition and method for production thereof

FIELD: chemistry.

SUBSTANCE: invention relates to powder metallurgy, particularly to production of a ferromagnetic powered composition. The composition can be used as a core in inductance coils, stators and rotors of electrical machines, drives, sensors and transformer cores. The composition contains a lubricant in form of solid particles and magnetically soft basic particles based on iron, the surface of which is coated with a first inorganic insulating layer based on phosphorus and at least one organometallic layer outside the first layer. The organometallic compound has the following general formula: R₁[(R₁)×(R₂)_y(MO_n-1)]_nR₁, where M is a central atom selected from Si, Ti, Al or Zr; O is oxygen; R₁ is a hydrolysable group; R₂ is an organic part in which at least one R₂ contains at least one amino group; n is the number of repeating structural units ranging from 1 to 20; x is an integer from 0 to 1; y is an integer from 1 to 2. The organometallic layer is strongly bound to a metal or semi-metal compound in form of solid particles, having Mohs hardness of less than 3.5.

EFFECT: obtaining material having high strength, maximum magnetic permittivity and inductance while minimising hysteresis loss and reducing eddy-current loss.

15 cl, 5 tbl, 5 ex

The technical FIELD of the INVENTION

The present invention relates to powder compositions comprising insulating powder based on iron, and to a method for producing these compositions. The invention additionally relates to a method for producing a soft-magnetic composite components prepared from the composition, and the obtained component.

The prior art INVENTIONS

Soft-magnetic materials are used for such practical applications as materials for cores in inductance coils, stators and rotors of electric machines, power actuators, the sensors and the cores of transformers. Traditionally soft-magnetic cores, such as rotors and stators of electrical machines, made from assembled into packets steel plates. The basis of the soft-magnetic composite (SMC) materials are magnetically soft particles, usually based on iron with insulating coating on each particle. Soft-magnetic composite components get by pressing the isolated particles with the use of traditional ways of pressing the powder metallurgy (PM), not necessarily with the lubricant and/or binder. Using the methods of powder metallurgy, it is possible to obtain materials with a higher degree of freedom in the structure of soft-magnetic to potichnyj (SMC) materials, than when using steel plates as soft-magnetic composite (SMC) materials can carry out three-dimensional magnetic flux and because methods of compaction can be obtained three-dimensional shape.

Two key characteristics of a component of the iron core is its magnetic permeability and core loss. Magnetic permeability material is a pointer to its ability to be magnetized or its ability to conduct magnetic flux. Permeability is defined as the ratio of the magnitude of the induced magnetic flux to magnetic field strength. If the magnetic material is exposed to an alternating magnetic field, energy losses occur because of the losses associated with hysteresis, and eddy current losses. Losses due to hysteresis (DC-losses), which constitute a major portion of the total losses of the core in most applications of electric motors, entail the need of the expenditure of energy to overcome the residual magnetic forces in the iron core component. These forces can be minimized by improving the purity and quality of the base powder, but most effectively by increasing the temperature and/or time of heat treatment (i.e. removal of the stress component. The eddy-current loss (AC-p is Teri) caused by the emergence of electric currents in the iron core of a component due to the change of magnetic flux, caused by alternating current (AC). In order to minimize eddy currents, requires a high electrical resistivity component. The level of electrical resistivity, which is required to minimize AC losses, depends on the type of practical applications (operating frequency) and the size of the component.

Research in the field of manufacturing components of magnetic cores by powder metallurgy methods using powder coated iron-based aimed at developing powder compositions of iron, which improve certain physical and magnetic properties without harmful effects on other properties of the final component. The required component properties include, for example, a high magnetic permeability in a broad frequency range, low core loss, high saturation magnetic flux density and high mechanical strength. The required properties of the powder include suitability for methods of compression molding, which means that the powder can be easily molded to a component with high density, which can be easily removed from the molding equipment without damaging the surface of the component.

Examples of published patents described below.

Patent US 6309748 (author Lashmore) describes ferromag any powder, having a size in diameter from approximately 40 to approximately 600 microns and a coating of inorganic oxides each particle.

Patent US 6348265 (author Jansson) announces the iron powder coated with a thin coating containing phosphorus and oxygen, powder coated, perfect for pressing into the soft-magnetic cores, which can be termoobrabotannyj.

Patent US 4601765 (author Soileau) announces pressed iron cores, which use iron powder, which is first coated with a film of silicate of alkali metal, and then overlapping the silicon polymer resin.

Patent US 6149704 (author Moro) describes ferromagnetic powder with an electrically insulating coating of phenolic resin and/or a silicon resin and necessarily from the Sol of titanium oxide or zirconium oxide. The resulting powder was mixed with the lubrication of metal stearate and pressed into the ferrite core.

Patent US 7235208 (author Moro) reports ferrite cores made of ferromagnetic powder with a binder, in which the dispersed ferromagnetic powder, where the insulating binder includes trifunctionally alkylpolyglycoside resin and optional inorganic oxide, carbide or nitride.

Additional documents in the field of soft magnets are Japanese patent application JP 2005-32489, having the publication number JP 2007-129154, author Yuuichi; Japanese patent application JP 2005-274124, having the publication number JP 2007-088156, author Maeda; Japanese patent application JP 2004-203969, having the publication number JP 2006-0244869, author Masaki; Japanese patent application 2005-051149,having the publication number 2006-233295, author Ueda and Japanese patent application 2005-057193, having the publication number 2006-245183, author Watanabe.

TASKS INVENTIONS

One object of the invention is the provision of a powder composition of iron-based, including insulating powder based on iron, pressed in the soft-magnetic components, high strength component which can be heat-treated at the optimum temperature without destroying the insulating coating powder based on iron.

Also object of the invention is the provision of a powder composition of iron-based, including insulating powder based on iron, pressed in the soft-magnetic components with high strength, high maximum magnetic permeability and high inductance while minimizing hysteresis loss and maintain low eddy current losses.

Also object of the invention is the provision of a method of producing a powder composition based on iron, without having the COI is whether any toxic or adverse environmental solvents or drying processes.

Also object of the invention is the provision of a method of producing extruded and optionally heat-treated soft-magnetic composite component based on iron having a low core loss, in combination with sufficient mechanical strength and acceptable magnetic flux density (induction) and the maximum magnetic permeability.

DISCLOSURE of INVENTIONS

To achieve at least one of the aforementioned objectives of the invention for other objectives of the invention that will be understood from the following description, the present invention relates to a ferromagnetic powder composition comprising soft-magnetic base particles based on iron, in which the surface of base particles provided the first inorganic insulating layer on the basis of phosphorus and at least one ORGANOMETALLIC layer located outside the first layer, ORGANOMETALLIC compounds having the following General formula:

R₁[(R₁)×(R₂)_y(MO_n-1)]_nR_1,

in which M is a Central atom selected from Si, Ti, Al or Zr;

O - oxygen;

R₁- hydrolyzable group;

R₂- organic part , in which at least one R₂contains at least one aminor the foam;

in which n is the number of repeated structural units, which is an integer in the range from 1 to 20;

in which x is an integer from 0 to 1;

in which y is an integer from 1 to 2;

in which metallic or semimetallic compound in the form of solid particles having a Mohs hardness of less than 3.5, firmly attached, at least one ORGANOMETALLIC layer;

and in which the powder composition further includes a lubricant in the form of solid particles.

The invention additionally relates to a method of making ferromagnetic powder composition comprising (a) mixing soft-magnetic base particles based on iron, the surface of which is electrically isolated inorganic insulating layer on the basis of phosphorus, with the ORGANOMETALLIC compound, as mentioned above; (b) optionally mixing the obtained particles with additional ORGANOMETALLIC compound, as mentioned above; (c) mixing the powder with solid particles of a metal or semimetal compounds having a Mohs hardness of less than 3.5; and (d) mixing the powder with solid particles in the lubricant.

Stage (C) may, but need not necessarily, be performed before stage b) in addition to performing after stage b) or instead of running after stage b) can be performed before stage b).

The invention additionally relates to a method of making magnetically soft composite materials, comprising: coaxial extrusion compositions in accordance with the invention, in the mold at a pressure of at least about 600 MPa; optional preheating the mold to a temperature below the melting temperature was added solid particles lubricants; removing the resulting crude material; and an optional heat treatment of the raw material. Composite component in accordance with the invention will typically have a content of P between 0.01 and 0.1% by weight of the component, the content of Si to the base powder of between 0.02 and 0.12% by weight of the component and the content of Bi between 0,05-0,35% by weight of the component.

A DETAILED DESCRIPTION of the INVENTION

The base powder

The particles of the soft-magnetic core iron-based can be ground with water, gas, or may be a sponge iron powder, although ground water powder is more preferred.

The particles of the soft-magnetic core iron-based can be selected from a group consisting mainly of pure iron, iron alloy Fe-Si, with up to 7% by weight, preferably up to 3% by weight of silicon, iron alloy selected from the group of Fe-Al, Fe-Si-Al, Fe-Ni, Fe-Ni-Co or combinations thereof. Basically, preferably pure iron, nab is emer, iron with constant impurities.

The particles may be spherical or irregular in shape, particles of irregular shape is more preferable. The average density may be between 2.8 and 4.0 g/cm³preferably between 3.1 and 3.7 g/cm³.

The average particle size in the core on the basis of iron is between 25 and 600 μm, preferably between 45 and 400 μm, most preferably between 60 and 300 μm.

The first coating layer (inorganic)

Particles of the core provide the first inorganic insulating layer, which is preferably based on phosphorus. This first coating layer may be performed using powder based on iron phosphoric acid, dissolved in water, or in organic solvent. In the solvents water-based optional add corrosion inhibitors and surfactants. The preferred method of coating powder particles based on iron described in the patent US 6348265. Treatment for phosphating may be repeated. Insulating inorganic coating on the basis of phosphorus to the core particles based on iron, preferably without any additives, such as dopant, corrosion inhibitors or surfactants.

The phosphate content in the layer 1 may be between 0.01 and 0.1 wt.% song.

Metallo the organic layer (second coating layer)

At least one metal-organic layer outside the first layer on the basis of phosphorus. ORGANOMETALLIC layer is an ORGANOMETALLIC compound of General formula

R₁[(R₁)×(R₂)_y(MO_n-1)]_nR_1,

in which M is a Central atom selected from Si, Ti, Al or Zr;

O - oxygen;

R₁-hydrolyzable group;

R₂is an integral part , in which at least one R₂contains at least one amino group;

in which n is the number of repeated structural units, which is an integer from 1 to 20 (between 1 and 20);

in which x is an integer from 0 to 1;

in which y is an integer from 1 to 2 (x can be 0 or 1, and y can be 1 or 2).

The ORGANOMETALLIC compound may be selected from the following groups: surface modifiers, binding agents or crosslinking agents.

R₁in the ORGANOMETALLIC compound may be alkoxygroup having less than 4, preferably less than 3 carbon atoms.

R₂is the organic part, which means that the group R₂contains organic part or share. R₂may include 1-6, preferably 1-3 carbon atoms. R₂may optionally include one or more heteroatom is in, selected from the group consisting of N, O, S and P. the Group R₂may be linear, branched, cyclic or aromatic.

R₂may include one or more of the following functional groups: amino, diamino, amido, imido, epoxy, hydroxyl, ethylenoxide, ureido, urethane, isocyanate, acrylate, glyceryltrinitrate, benzylamino, universalbinary. The group R₂may vary between any of the aforementioned functional groups R₂and a hydrophobic alkyl group with repeated structural units.

ORGANOMETALLIC compound may be selected from derivatives, intermediates or oligomers silanes, siloxanes and silsesquioxanes or relevant titanates, aluminates or zirconates.

In accordance with one embodiment, at least one ORGANOMETALLIC compound in one ORGANOMETALLIC layer is a monomer (n=1).

In accordance with another embodiment, at least one ORGANOMETALLIC compound in one ORGANOMETALLIC layer is an oligomer (n=20).

In accordance with another embodiment of ORGANOMETALLIC layer located outside the first layer is a monomer ORGANOMETALLIC compound, and where the extreme ORGANOMETALLIC layer is oligose the om ORGANOMETALLIC compound. It is necessary that the chemical functionality of the monomer and oligomer were not the same. The weight ratio of the layer monomer ORGANOMETALLIC compound and a layer of oligomer ORGANOMETALLIC compounds may be between 1:0 and 1:2, preferably between 2:1-1:2.

If the ORGANOMETALLIC compound is a monomer, it can be selected from the group dialkoxy and dialkoxybenzene, titanates, aluminates or zirconates. The monomer ORGANOMETALLIC compound may, therefore, be selected from 3-aminopropyl-trimethoxysilane, 3-aminopropyl-triethoxysilane, 3-aminopropyl-diethoxyethane, N-amino-ethyl-3-aminopropyl-trimethoxysilane, N-amino-ethyl-3-aminopropyl-methyl-dimethoxysilane, 1,7-bis(triethoxysilyl)-4-usahatani, treatmentonline propyl-trimethoxysilane, 3 ureido-propyl-triethoxysilane, 3-isocyanatopropyl-triethoxysilane, Tris(3-triethoxysilylpropyl)-isocyanurate, 0-(propargyloxy)-N-(triethoxysilylpropyl)-urethane, 1-aminomethyl-triethoxysilane, 1-amino-ethyl-methyl-dimethoxysilane or mixtures thereof.

Oligomer ORGANOMETALLIC compound may be selected from alkyl-alkoxysilanes silane-terminated alkoxygroup, titanates, aluminates or zirconates. Oligomer ORGANOMETALLIC compound may, therefore, be selected from aminosilicones, Zack is nelaudis methoxy-, ethoxy or acetoxypropionyl, aminosilicones, oligomeric 3-aminopropyl-ethoxysilane, 3-aminopropyl/propyl-alkoxysilanes, N-amino-ethyl-3-aminopropyl-alkoxysilanes or N-amino-ethyl-3-aminopropyl/methyl-alkoxysilanes or mixtures thereof.

The total number of ORGANOMETALLIC compounds may be from 0.05 to 0.6%, preferably of 0.05-0.5%, more preferably 0.1 to 0.4%, and most preferably of 0.2-0.3 % by weight of the composition. These types of ORGANOMETALLIC compounds may be commercially available from companies such as Evonik Ind., Wacker Chemie AG, Dow Corning, etc.

ORGANOMETALLIC compound is alkaline in nature, and may also include binding properties, for example, the so-called binding agent to attach the powder based on iron to the first inorganic layer. The substance should neutralize excess acids and acidic by-products from the first layer. If you are using binding agents group aminoalkylsilanes, titanates, aluminates or zirconates, the substance is hydrolysed and partially polymerized (some alkoxygroup will be hydrolyzed with the formation of, respectively, alcohols). Great value for joining metallic or semimetallic compound in the form of solid particles also provide a binding or cross-linking properties of ORGANOMETALLIC from the of dinani, which can improve the mechanical strength of the molded composite connection.

Metallic or semimetallic compound in the form of solid particles

Soft-magnetic powder based on iron coated must also contain at least one compound of a metal or semimetal, in the form of solid particles. Metallic or semimetallic compound in the form of solid particles should be soft, with a Mohs hardness of less than 3.5, and should represent small particles or colloidal material. Preferably, the connection could have an average particle size less than 5 microns, preferably less than 3 microns and most preferably below 1 μm. Metallic or semimetallic compound in the form of solid particles may have a purity of more than 95%, preferably more than 98% and most preferably more than 99% by weight. The Mohs hardness of the metal or semimetal compounds in the form of solid particles is preferably less than 3, more preferably less than 2.5 or less. SIO, SIS₂, Al₂O₃, MgO and TiO₂are abrasive and have a Mohs hardness is much higher than the 3.5 and are outside the scope of the invention. Abrasive compounds, even in the form of particles having nano, cause irreversible defects in insulating p. the closure, leading to poor recovery and the worst of magnetic and/or mechanical properties of the component subjected to the heat treatment.

Metallic or semimetallic compound in the form of solid particles may be at least one selected from the group of lead, indium, bismuth, selenium, boron, molybdenum, manganese, tungsten, vanadium, antimony, tin, zinc, cerium.

Metallic or semimetallic compound in the form of solid particles may be an oxide, hydroxide, carbonate, phosphate, fluoride, sulfide, sulfate, sulfite, oxychloride or mixtures thereof.

In accordance with a preferred embodiment of a metal or semimetal compound in the form of solid particles is bismuth or more preferably the oxide of bismuth (III). Metallic or semimetallic material in the form of solid particles may be mixed with a second compound selected from alkaline or alkaline-earth metals, in which compounds may be carbonates, preferably the carbonates of calcium, strontium, barium, lithium, potassium or sodium.

Metallic or semimetallic compound in the form of solid particles may be present in an amount of 0.05-0.5%, preferably in an amount of 0.1-0.4% and most preferably in the amount of 0.15 to 0.3 % by weight of the composition.

Metal or semimetal with the Association in the form of solid particles interlock at least one ORGANOMETALLIC layer. In one embodiment of the invention the metallic or semimetallic compound in the form of solid particles bonded with extreme ORGANOMETALLIC layer.

Grease

Powder composition in accordance with the invention includes a lubricating substance in the form of solid particles. The lubricating substance is in the form of solid particles plays an important role and allows you to perform extrusion without lubrication on the walls of the mold. The lubricating substance is in the form of solid particles may be selected from the group consisting of primary and secondary amides of fatty acids, TRANS-amides (bis-amides or alcohols of fatty acids. Lubricating the proportion of lubricant in the form of solid particles may be saturated or unsaturated chain containing 12-22 carbon atoms. The lubricating substance is in the form of solid particles may preferably be selected from stearamide, erucamide, stearinerie, erucyl-stearamide, BeginInvoke alcohol, erollover alcohol, ethylene-bis-stearamide (e.g., ELS or amide wax). The lubricating substance is in the form of solid particles may be present in an amount of 0.15-0,55%, preferably in quantities of 0.2-0.4% by weight of the composition.

The method of preparation of the composition

Method of preparation of ferromagnetic powder with the composition in accordance with the invention includes: (a)mixing soft-magnetic core particles based on iron, in which the surface of the particle core is electrically isolated inorganic insulating layer on the basis of phosphorus, with the ORGANOMETALLIC compound, as described above; (b) optional mixing the obtained particles with additional ORGANOMETALLIC compound as described above; (c) mixing the powder with solid particles of a metal or semimetal compounds having a Mohs hardness of less than 3.5; and (d) mixing the powder with solid particles of the lubricant with the lubricant in the form of solid particles). Stage (C) may, but need not necessarily, be performed before stage b) in addition to performing after stage b) or instead of running after stage b) can be performed before stage b).

Solid particles of the core, provided the first inorganic insulating layer may be pretreated with an alkaline compound before they mix with the ORGANOMETALLIC compound. Pre-processing can create good conditions for binding between the first and second layers, which can improve electrical resistivity and mechanical strength of the magnetic composite component. The alkaline compound may be selected from ammonia, hydroxylamine, tetraallylsilane ammonia, alkylamines followed, alkylamides. Preliminary about abode can be carried out using any of the above chemicals, preferably diluted with an appropriate solvent, mixed with the powder and optionally dried.

The method of obtaining soft-magnetic components

The method of preparation of the soft-magnetic composite material in accordance with the invention includes: coaxial extrusion compositions in accordance with the invention in the mold at a pressure of at least about 600 MPa; optionally pre-heating the mold to a temperature below the melting temperature was added solid particles lubricants; removing the resulting crude material; and optional heat treatment of the raw material.

Pressing can be cold, hot or high speed, it is preferable to use an adjustable temperature mold (50-120°C) for unheated powder.

The heat treatment may be carried out in a vacuum, not reducing, inert or slabokislami atmosphere, for example, from 0.01 to 3% oxygen or in an atmosphere of steam, which may promote the formation of inorganic lattice, but without increasing the coercive force pressed powder blanks. The optional heat treatment is performed in an inert atmosphere, and then perform a fast shutter speed in an oxidizing atmosphere such as steam, to build a solid surface the CSOs layer of higher strength. The temperature can be up to 700°C.

Heat treatment conditions should allow lubricating substance to evaporate as fully as possible. This exercise usually during the first part of the cycle of heat treatment at a temperature higher than approximately 300 to 500°C. At higher temperatures the metal or semimetal compound may react with the ORGANOMETALLIC compound and partially to form a glassy lattice. This further enhances the mechanical strength, but also increases the electrical resistivity of the component. When the maximum temperature (600-700°C), it is possible to achieve complete relief in powder injection molded workpiece at which the coercive force and, consequently, the hysteresis loss of the composite material will be minimized.

Pressed and heat treated soft-magnetic composite material prepared in accordance with the invention preferably has a content of P between 0.01 and 0.1% by weight of the component, the content of Si to the base powder of between 0.02 and 0.12% by weight of the component and the content of Bi between 0,05-0,35% by weight of the component.

The invention is additionally illustrated by the following examples.

EXAMPLE 1

As source material used ground water to the powder core is ve iron, having an average particle size of about 220 μm and having less than 5% of particles with size less than 45 μm (powder 40 mesh). This powder, which is a pure iron powder was first covered with a thin insulating layer on the basis of phosphorus (phosphorus content in which approximately 0,045% by weight of powder coated). Then it was mixed with the oligomer aminoalkyl-alkoxysilane (Dynasylan^®1146, Evonik Ind.) in the amount of 0.2% by weight. The composition was further mixed with fine particles of oxide powder of bismuth (III) in an amount of 0.2% by weight. Were used for comparison the corresponding powders without surface modification using silane and bismuth, respectively. The powder prior to pressing finally mixed with the lubricant ELS (EBS) in the form of solid particles. The number of used lubricants was 0.3% by weight of the composition.

Ring cores with an inner diameter of 45 mm and an outer diameter of 55 mm and a height of 5 mm were aligned compressed in a single stage with two different pressing pressures of 800 and 1100 MPa, respectively; the temperature of the mold 60°C. After pressing, the items were subjected to heat treatment at 650°C for 30 min in nitrogen. The standards were treated at 530°C for 30 min air (A6, A8) and (water) steam (A7). The obtained subjected t is Samoobrona ring cores were wound 100 turns of the measuring coil and 100 turns of coil excitation. Magnetic measurements were carried out on samples of ring cores for 100 turns of coil excitation and 100 turns of the measuring coil using hysteresisgraph from Brockhaus. Overall, the core losses were measured at 1 Tesla, 400 Hz and 1000 Hz respectively. The resistance of the transverse rupture was measured according to ISO 3995. Specific electrical resistivity was measured on all samples coils using a four-point measuring method.

The following table 1 shows the results:

On magnetic and mechanical properties adversely affected by the exclusion of one or more layers of the coating. The exclusion layer based on phosphate will result in unacceptable resistivity, which will increase, thus, the eddy-current loss (A3). The exception ORGANOMETALLIC compound will result in unacceptable resistivity and unacceptable mechanical strength (A4, A5).

Compared with existing industry standards, such as Somaloy^®Somaloy 700 or^®3P, available from Hëganäs AB, Sweden (A6-A8), composite materials of the present invention may be subjected to heat treatment at a higher temperature, which reduces the hysteresis loss (DC-loss/cycle).

NOTE THE R 2

As source material used crushed water-based powder of iron, having an average particle size of 95 μm and 10-30% of particles having a size less than 45 μm (powder 100 mesh), with the observed density of about 3.3 kg/cm³the particles of iron, surrounded by the electrically insulating layer on the basis of phosphates. Powder coated was further mixed with 0.2% by weight of aminoalkyl-trichlorsilane ((Dynasylan^®Ameo), and then mixed with 0.2% by weight of the oligomer, aminoalkyl/alkyl-alkoxysilane (Dynasylan^®1146), both manufactured by Evonik Ind. The composition was further mixed with 0.2% by weight of fine powder of oxide of bismuth (III). Finally, before pressing, the powder was mixed with the lubricant ELS (EBS) in the form of solid particles. The number of used lubricants amounted to 0.4% by weight of the composition. Powder compositions were further processed as described in example 1, but using 600 and 800 MPa, respectively. Table 2 shows the results.

SAMPLE 3

Was used the same base powder as in example 1, with the same insulating layer on the basis of phosphorus. This powder was mixed with various amounts of the first main aminoalkyl-alkoxysilane ((Dynasylan^®Ameo), and then with Oleg the mayor of aminoalkyl/alkyl-alkoxysilane (Dynasylan ^®1146), in the ratio of 1:1, both manufactured by Evonik Ind. Composition in conclusion, mixed with varying amounts of fine powder of bismuth oxide (III)(>99 wt.%; D50 of~0.3 µm). Sample C5 is stirred with Bi₂O₃a lower degree of purity and large particles (>98 wt.%; D50~5 µm). In conclusion, the powder composition was mixed before pressing at 1100 MPa with different amounts of amide wax (ELS). Advanced powder compositions were processed as described in example 1. The results shown in table 3 and show the effect on the magnetic properties and mechanical strength (resistance to transverse tear-TRS).

Samples C1 through C4 illustrate the effect of using various amounts of ORGANOMETALLIC compounds, bismuth oxide or lubricants. Sample C5 has a lower electrical resistivity, but TRS is slightly improved as compared with sample C6.

EXAMPLE 4

Was used the same base powder as in example 1, with the same insulating layer on the basis of phosphorus, except for samples D10 (0.06 wt.% P) and D11 (0.015 wt.% P). Samples of powders with D1 through D11 were additionally processed in accordance with table 4. In conclusion, all samples were mixed with 0.3 wt.% ELS (EBS) and compacted at 800 MPa. MAGN the IDT-soft components were then additionally subjected to heat treatment at 650°C for 30 min in nitrogen.

Samples D1 through D3 illustrate that layer, or 2-1, or 2-2 can be excluded, but the best results will be obtained when the combination of both layers. Samples D4 and D5 illustrate the powders subjected to pretreatment using dilute ammonia, followed by drying at 120°C for 1 h in air. Pre-treated powders were additionally mixed with amidofunctional oligomeric silanes having acceptable properties.

Samples D10 and D11 illustrate the effect of phosphorus content in the layer 1. Depending on the properties of the base powder, such as the distribution of the solid particle size and morphology of particles, there is an optimal concentration of phosphorus (between 0.01 and 0.1 wt.%) in order to obtain all of the required properties.

EXAMPLE 5

Was used the same base powder as in example 1, with the same insulating layer on the basis of phosphorus. All three samples were subjected to the same treatment as the sample D1, except that the metal connection was different. Sample E1 shows that the electrical resistivity is improved, if the oxide of bismuth (III) in a small amount of added calcium carbonate. Sample E2 shows the influence of another soft metal compounds MoS2.

Unlike adding abrasive and solid soy is ineni with Mohs hardness below 3.5 adding abrasive and solid connections with Mohs hardness of significantly higher 3,5, such as corundum (Al₂O₃) or quartz (SiO₂), will lead to the fact that the properties of soft magnets will be unacceptable due to insufficient electrical resistivity and mechanical strength, despite the fact that the particles are nanosized.

1. The ferromagnetic powder composition comprising soft-magnetic base particles based on iron, in which the surface of base particles provided with the first inorganic insulating layer on the basis of phosphorus and at least one ORGANOMETALLIC layer located outside the first layer, ORGANOMETALLIC compounds having the following General formula:
R₁[(R₁)x(R₂)_y(MO_n-1)]_nR_1,
in which M is a Central atom selected from Si, Ti, Al or Zr;
O - oxygen;
R₁- hydrolyzable group;
R₂- organic part and in which at least one R₂contains at least one amino group;
in which n is the number of repeated structural units, which is an integer in the range from 1 to 20;
in which x is an integer from 0 to 1;
in which y is an integer from 1 to 2;
in which metallic or semimetallic compound in the form of a solid the particles, having a Mohs hardness of less than 3.5, firmly attached, at least one ORGANOMETALLIC layer;
when this powder composition further includes a lubricant in the form of solid particles.

2. The composition according to claim 1, in which the aforementioned ORGANOMETALLIC compound in one ORGANOMETALLIC layer is a monomer (n=1).

3. The composition according to claim 1 or 2, in which the aforementioned ORGANOMETALLIC compound in one ORGANOMETALLIC layer is an oligomer (n=2-20).

4. The composition according to claim 1 or 2, in which R₁in the ORGANOMETALLIC compound is alkoxygroup having less than 4, preferably less than 3 carbon atoms.

5. The composition according to claim 1 or 2, in which R₂includes 1-6, preferably 1-3 carbon atoms.

6. The composition according to claim 1 or 2, in which R₂group ORGANOMETALLIC compound includes one or more heteroatoms selected from the group consisting of N, O, S and P.

7. The composition according to claim 1 or 2, in which R₂includes one or more of the following functional groups: amino, diamino, amido, imido, epoxy, mercapto, disulfide, chloralkali, hydroxyl, ethylenoxide, ureido, urethane, isocyanate, acrylate, glyceryltrinitrate group.

8. The composition according to claim 1 or 2, in which the ORGANOMETALLIC compound is a monomer that is selected from trialconsistent and dialkoxybenzene, the titanates, aluminates or zirconates.

9. The composition according to claim 1 or 2, in which the ORGANOMETALLIC compound is an oligomer selected from the ending alkoxygroup of alkyl/alkoxylation silane, titanate, aluminate or lead zirconate.

10. The composition according to claim 3, in which the oligomer ORGANOMETALLIC compound selected from ending alkoxygroup of aminosilicones, amino-siloxanes, oligomeric 3-aminopropyl-alkoxysilane, 3-aminopropyl/propyl-alkoxysilane, N-amino-ethyl-3-aminopropyl-alkoxysilane or N-amino-ethyl-3-aminopropyl/methyl-alkoxysilane or mixtures thereof.

11. The composition according to claim 1 or 2, in which the metal or semimetal compound in the form of solid particles or bismuth is preferably an oxide of bismuth (III).

12. A method of obtaining a ferromagnetic powder composition according to any one of paragraphs. 1-11, including:
a) mixing of the soft-magnetic base particles based on iron, the surface of which elektrosokirani inorganic insulating layer on the basis of phosphorus, with ORGANOMETALLIC compounds;
b) optionally mixing the obtained particles with additional ORGANOMETALLIC compound;
c) mixing the powder with solid particles of a metal or semimetal compounds having a Mohs hardness of less than 3.5; and
d) mixing orosco solid particulate lubricant,
when carrying out the mixing of the particles with additional ORGANOMETALLIC compound mixing of the powder with solid particles of metal or polymetallics compounds having a Mohs hardness of less than 3.5, carried out before and/or after it.

13. Method of preparation of magnetically soft composite materials, including:
(a) axial pressing of the ferromagnetic powder composition according to any one of claims 1 to 11 in the mold at a pressure of at least about 600 MPa;
b) optionally pre-heating the mold to a temperature below the melting temperature was added solid particles lubricants;
c) removing the obtained green material; and
d) optional heat treatment of green material.

15. Pressed and heat treated soft-magnetic composite material prepared in accordance with 14 having a P content between 0.01 and 0.1% by weight of the component, the content of Si to the base powder of between 0.02 and 0.12% by weight of the component and the content of Bi between 0,05-0,35% by weight of the component.