TWI229018B - Iron-based powder - Google Patents

Abstract

The present invention concerns a new ferromagnetic powder composition comprising soft magnetic iron-based core particles wherein the surface of the core particles are surrounded by an insulating inorganic coating, and a lubricating amount of a compound selected from the group consisting of silanes, titanates, aluminates, zirconates, or mixtures thereof. The invention also concerns a process for the preparation of soft magnetic composite materials using the new powder composition.

Description

1229018 Rose, description of the invention: [Technical field to which Ming belongs] The present invention relates to a novel metal generation " To be more specific, this month is about a novel iron-based ^ y-based scroll end, which is useful in the preparation of soft magnetic materials that have right- and good-quality characteristics when used on both low and low frequencies. . The invention also relates to a method for gasifying soft magnetic composite materials prepared with water. [Previous technology] Soft magnetic materials are used in applications, such as core materials, actuators, and sensors in electrical machinery, inductors, stators and rotors And the transformer ㈣Μ. · :) Nuclear. Traditionally, soft magnetic cores, such as rotors and stators in electrical machinery, are made of stacked steel laminates. The soft magnetic composite, SMc, is based on soft magnetic particles, usually iron-based, with an electrically insulating coating on each particle. These components can be obtained by selectively compacting these insulating particles with a lubricant and / or adhesive by conventional powder metallurgy methods. Using this powder metallurgy technology, it is possible to manufacture a material with a higher degree of freedom in the SMC composition design than using such steel laminates as the SMC material, which can contain three-dimensional magnetic flux and can be obtained using the compaction method Three-dimensional shape. The key characteristics of an iron core composition are its magnetic permeability (magneUc permeability) and core loss (core 〇ss) characteristics. The permeability of a material is an indication of its ability to become magnetized or its ability to carry a magnetic flux. Permeability is defined as the ratio of induced magnetic flux to magnetizing force or field strength. O: \ 90 \ 90403.DOC -6- 1229018 When a magnetic material is exposed to a changing field, energy loss can occur due to both hysteresis losses and eddy current losses. Hysteresis loss is caused by the energy consumption required to overcome the magnetic force held in the iron core composition. Eddy current losses are caused by a change in magnetic flux caused by alternating current (AC) conditions, which generates a current in the iron core composition. A high resistivity of this composition is expected to minimize eddy currents. Research on metallurgical manufacturing of powdered magnetic core composition using coated iron-based powder cores has been directed towards the development of iron powder composition, which strengthens the physical and magnetic properties of the alloy and does not adversely affect the final composition Other special features. Expected compositional characteristics include, for example, low core loss at s / z over a wide frequency range, high residual and saturation mduction, and high strength. Generally increasing the composition density will strengthen all k-two characteristics, if the right can maintain sufficient resistivity. The expected applicability of the powder to the compression molding technology, which means that the powder can be easily formed into a high-density composition, which can be easily ejected from the molding equipment without damaging the composition surface . [Summary of the Invention] The present invention relates to a kind of ferromagnetic powder composition which is compacted to a density of more than eight. combination. More specifically, the present invention is | a powder composition, # 冬 包 3 soft magnetic iron or iron-based core granules ^ its surface is surrounded by _ 雷 纟 Yue Wu two insulating inorganic coatings, and its composition It is also included that it is sufficient to produce a lubricating effect, such as sinter, acetic acid, acetic acid, or acetic acid. The present invention also includes a method for preparing high-density raw embryos by selectively applying various components to selectively heat treatment, Kidney ^ μ method. This method includes providing the 矣

O: \ 90 \ 90403 D0C 1229018 The combination of materials and additives, such as Xi (that is, Tehejiao, and flow wenhai: in agents), under high waste ^^… in-single-axis tightening The green body is ejected from the house, which can be subjected to steps such as heat treatment. [Embodiment] The ferromagnetic powder used here is composed of iron or an alloy containing iron selected from the group consisting of Nm element and iron, which is selectively or in combination with a weight percentage f to 2G%. Preferably, the novel powder is soil; a base powder mainly composed of pure iron. This powder may be, for example, a commercially available hydrated (gas-atmised) or gas_atmised iron powder or reduced iron powder, such as sea_powder. The powder particle shape may be round, irregular, or flat. A preferred electrically insulating coating, which can be used in accordance with the present invention, is a thin scaly coating of the type described in U.S. Patent No. 6,348,265, which is incorporated herein by reference. Among other things, preferably inorganic coatings can be used, such as coatings based on chromium, ballast, zinc, zinc, or indium. The lubricants used in accordance with the present invention are of the organic_shiyaki, organic_titanate, organic-aluminate, or organic-gallate type. Such substances are often called interface modifiers, binders, or crosslinkers, depending on the chemical function of the functional group. The specific types of organic alkanes, organic-titanates, organic-aluminates, or organic-acetates used in accordance with the present invention and which may be referred to as organic-metal compounds are composed of at least one hydrolyzable functional group and at least The presence of lubricating organic parts is identified. This type of compound can be defined by the general formula: M (Rl) n (R2) m

O: \ 90 \ 90403.DOC 1229018 where M is a central atom selected from silicon, titanium, aluminum, and rhenium; R1 is a hydrolyzable functional group; R2 is a functional group composed of a lubricating organic portion; where m The sum of + n must be equal to the coordination number of the central atom, and η is an integer of -1 and m is an integer of g 1. Specifically, 1 ^ is an alkoxy group having less than 12 carbon atoms. Alkoxy groups having less than 6 carbon atoms are preferred, and more preferred are alkoxy groups having 1 to 3 carbon atoms. Ri may also be a sweetened group, such as a residue of hydroxyacetic acid (-OC (0))-CH20) or a residue of ethylene glycol (-OCH2CH20-). R2 is an organic group containing 6-30, preferably 10-24 carbon atoms, and optionally one or more hetero atoms selected from nitrogen, oxygen, sulfur, and phosphorus. R2 is a functional group consisting of an organic moiety, which is not easily hydrolyzed and is usually lipophilic, and may be a calcined group, scale, ester, phosphorus-alkyl, phosphorus-lipid, or phosphorus-amine chain. Phosphorus may exist in the form of a phosphatoto, a pyrophosphato, or a phosphito group. In addition, R2 may be linear, branched, cyclic, di- or aromatic. According to the present invention, the preferred lubricating silane groups are alky 1-alkoxy silanes and polyether-alkoxy silanes. In addition, hexadecyl-trimethoxy silane, isopropyl-triisostearyl titanate, and isopropyl-tri (dioctyl) linoleic acid were used. Isopropyl-tri (dioctyl) phosphato titanate, neopentyl (dipropyl) oxy-tris (dioctyl) scale acid oxalate O: \ 90 \ 90403 D0C -9- 1229018 (neopentyl (diallyl) oxy-tri (dioctyl) phosphato zirconate), neopentyl (diallyl) oxy-trineodecanylyl ester (neopentyl (diallyl) oxy-trineodecanoyl zirconate) ^ and Diisobutyl-acetoacetyl aluminate | Diisobutyl-acetoacetyl aluminate has obtained promising results. The amount of the compound is preferably present in an amount greater than 0.05% by weight of the composition, such as 0.05-0.5%, preferably 0.07-0.45%, and most preferably 0.08-0.4%. Too low a quantity of lubricant will result in high density, but will result in a poor injection state and may therefore result in a poor surface state of the tool and / or SMC component. However, if the amount is too large, an excellent injection state is produced ', but it may become a low composition density. Further, it is preferable that the compound exists in the form of a lubricating layer on the insulating particles. However, it should be noted that the composition, the material configuration and the quality of the tool have a great influence on the surface state of the SMC part after injection. The use of organic stone yakigan organic " Qin acid s purpose, or organic " Ming acid g purpose compounds is known in US Patent Nos. 4,820,338 and 6,537,389. According to U.S. Patent No. 4,820,338, the use of gadolinium, titanic acid, or sodium vinegar is to accelerate the coupling between such magnetic powder particles and an electrically insulating organic binder polymer. These powder particles do not have an inorganic coating. U.S. Patent No. 6,537,389 discloses a wide range of cutting, chain-containing, or rotten compounds used as molecular precursors for the manufacture of electrical insulating ceramics on soft magnetic powders. These precursor compounds are converted to Taurman, metal or intermetallic end products by heat treatment to enhance temperature and solvent resistance. U.S. Patent No. 6,537’389 is using this organometallic compound as a manufacturing chemical and

O: \ 90 \ 90403.DOC -10- 1229018 The thermally resistant coating precursor can be distinguished from the present invention in that it is not a key component that facilitates the manufacture of high density parts. In addition, the precursor compounds described in the U.S. Patent: No. 7,389 do not include a lubricating part. The lubricating compound used in accordance with the present invention may be used to dissolve or disperse it in a suitable solvent, such as , An organic solvent, such as propylene: or ethanol. The resulting solution or dispersant is then added to the iron-based powder during mixing and selective heating. The solvent will eventually evaporate, optionally under vacuum. According to an embodiment of the present invention, the powder has coarse particles', that is, the powder is substantially free of fine particles. The phrase "substantially free of fine particles" is intended to indicate that the iron or iron-based powder particle size is less than about 5%, as measured by the method described in SS_EN 24 497. By far the most interesting results have been obtained with powders consisting essentially of particles larger than about 106 micrometers' and especially larger than about 212 micrometers. The wording "consisting essentially of" is intended to mean 40% less, preferably at least 60% of these particle sizes are larger than ⑽ and 212 nm, respectively. The best results up to the moment M were obtained by making powders with an average particle size of about megameters and less than 3% and less than 1 (6) microns. The largest particle size is about 5 mm. Iron-based powder particle size cloths used in PM manufacturing have a Gaussian distribution with an average particle diameter in the range of 30 to 100 microns and about 10-30% below 45 microns. An iron-based powder having substantially no fine powder can be obtained by removing a finer portion of the powder or by manufacturing a powder having a desired particle size distribution.

O: \ 90 \ 90403.DOC -11-1229018 According to the preferred embodiment of the present invention and contrary to the general practice of powder metallurgy, the conventional PM lubricant is used in iron powder mixing, or the lubricant and Adhesives and / or surface treatments are used in combination. The iron or ^ -based powder must not be separated from the separated (special slide sword, ei,) before being transferred to the die. It is also not necessary to use an external lubricant (die wall lubricant), in which the die wall is supplied with lubricant before compaction is performed. However, the present invention does not exclude the possibility of using conventional internal lubricants (up to 0 to 5% by weight), external lubricants, or a mixture of the two when needed. The powder to be compacted may also contain additives selected from the group consisting of adhesives, lubricants, and flow aids. Examples of the inorganic lubricant, which can be used in addition to the organic PM lubricant, are hexagonal boron nitride and molybdenum disulfide. According to the present invention, a soft magnetic composite material having a density of at least 7 45 grams per cubic centimeter can be prepared by the novel powder composition in a uniaxial compaction die under high compaction pressure and without die wall lubrication. When the green embryo body has been ejected from the compacting tool, it can be as high as about 700. 〇 to perform heat treatment. The expression "β is pressed tightly" is intended to mean under a pressure of at least about 8005 ^^^). More interesting results are obtained at higher pressures, e.g. about 900, more preferably about 1000, and optimally about 1 million megapascals. Conventional compaction under high pressure, that is, a pressure greater than about 800 million Pascals, is generally considered unsuitable for use in powders containing finer particles used because the compacted entity is to be ejected from the die. Very high forces are required, the southness of the die attached to the die 'and the fact that the surface of these compositions tends to be less shiny or degraded. Although high compaction pressure is used to achieve high density, high resistivity is still obtained. By using the powder according to the invention, it was unexpectedly found

O: \ 90 \ 90403.DOC • 12-1229018 The injection force has a composition with acceptable or even perfect surface under the pressure of 1_mpa. And it can be made that the compact dust can be performed using standard equipment without expensive investment. The compact plant is shown in single and two, and the Ying method can be performed in a single step at ambient or elevated temperatures. : PerCUSSioma maChine (Hyd ^-^ ^ ΗΥTP :: type side-assisted implementation, such as in Patent Publication 1: Ordering in different types of gas plants or under reduced pressure and selective presence It is performed at a temperature generally used, for example, as high as a gift. Prior to the heat treatment, the compacted composition can optionally be greened or cleaned. The main purpose of the present invention is to obtain a high-density product. The coarse powder as described above is preferably used. However, it has also been found that these lubricating effects can also be obtained by using a powder containing a relatively large amount of fine particles, that is, the type of powder generally used in the current PM industry. Example 3 below And 5 illustrate the lubricating effect of the organic-metal compound according to the present invention on both conventional powders and coarse powders. As can be observed, high density is also obtained on the use of conventional powders containing relatively large amounts of fine particles. Particle size The distribution is currently-used and has a lubricant according to the invention. Iron-containing or iron-based powder compositions may be of particular interest for specific applications. Within the scope of the invention. "咼 density" of the term is intended to mean density of at least about the tight entity "g / cc's." High density "is not an absolute value. According to the status of art, of

O: \ 90 \ 90403.DOC • 13-1229018 For a single heat treatment and a single compacting composition, it can generally reach a density of 7.2 grams per cubic centimeter. By using warm compaction, an increase of about 0.2 g / cm3 can be achieved. In this context, the term "high fork" is intended to mean a compact with a density of about 7 45_7 65 g / cm3 or more, 'depending on the type and amount of additives used and the type of iron-based powder used . Of course it is also possible to make lower density compositions ' but Xianxin is less interesting. Jian Luzhi 'advantage obtained by using the powder and method according to the present invention is that high-density SMC parts can be manufactured cost-effectively. SMC parts with very high magnetic induction levels and low core losses can be made. Other advantages are that the mechanical strength after heat treatment can be increased, and in addition to very high density, compacted parts with high resistivity can be successfully ejected from the die without negatively affecting the polishing of the die wall and / or the Squeeze the surface of the SMC part. It is therefore possible to obtain parts with excellent surface finishes. These results can be obtained with a single compaction step. Examples of novel powder compact solid products that are of particular interest are inductors, stators and rotors, actuators, inductors, and transformers of electrical machinery (Transformer) core. The invention is further illustrated by the following examples. It should be understood that the present invention is not limited thereto. Example 1 An iron-based hydration powder (Somaloy 55TM, available from H ^ ganas AB, Sweden) was used. The average particle size of this powder is between 212 and 425 microns, and particles below 5% have particles below 粒 microns. O: \ 90 \ 90403.DOC -14-1229018 sub-size. This powder, which is pure iron powder, whose particles are electrically insulated by a thin layer containing scale barriers, is used as a lubricant with a hexadecyl-trimethoxystone sintering content of 0.2% by weight. h⑽deCyl-trimethoxy siiane)-starting treatment. The addition of the lubricant was performed as follows: The hexadecyl-trimethoxysilane was diluted in ethanol to a solution of 20% by weight, and the solution was stirred for 6 G minutes. When mixed with the iron powder, this solution was added in an amount corresponding to 0.2% by weight, which had been previously heated to 75 ° C in a mixer. Thorough stirring was performed in the same mixer for 3 minutes, followed by mixing at a lower speed for 30 minutes, and the solvent was evaporated under vacuum. A corresponding powder mixed with a conventional lubricant was used for comparison. Mix this powder with KenuolubeTM before compacting. The amount of lubricant used is 0.5% of the composition, which is generally considered a low amount of lubricant for a composition compacted under high pressure. A single step of pressing a ring with an inner diameter of 47 mm, an outer diameter of 55 mm, and a height of 4¾ meters under different pressing pressures of 800, 100, and 1,200 MPa, respectively. . Except for low amounts of organic-metal lubricants and high compaction pressure, the surface of this composition shows no signs of degradation. After pressing, the parts are placed at 500. Heat treatment in air at 30 ° C for 30 minutes. The obtained heat-treated ring was wound with 25 senses and 112 drive revolutions. Magnetic properties are measured in HySteresigraph LDJ 3500. Table 1 summarizes the maximum relative permeability and magnetic induction at 1500 and 6900 amps / meter (A / m), respectively, measured under DC conditions. Core loss / cycle is also measured at 50 Hz and 400 Hz at atmospheric pressure. O: \ 90 \ 90403.DOC -15- 1229018 Table 1 Sample port r Ια »Compression pressure MPa Density g / cm3 // Maximum Bl500 (T) B6900 (T) Core loss / cycle at IT and 50Hz (J / kg) Core loss / cycle at IT and 400Hz (J / kg) According to the present invention 800 7.45 720 1.08 1.53 0.134 0.178 1000-7.59 790 1.15 1.59 0.126 〇163 1200 7.64 820 11.18 1.62 0.124 \ J, X \ J 0 165 Comparative Example 800 7.39 620 0.95 1.46 Factory 0.142 vy · x \ j 0.200 1000 17.47 590 0.95 1.49 0.140 〇 〇 〇 1200 7.49 550 0.92 1.48 0.140 0.193 As can be seen in Table 1, for those according to the present invention, In terms of powder, the greenness of the raw embryo is relatively south, so magnetic properties are improved compared with the materials used in the comparative examples. This comparative example also shows that by increasing the compression pressure to 1000 MPa and 1200 MPa, only a little or even no improvement in magnetic properties can be obtained. In addition to the high density of the samples produced, the core loss is maintained at a low level, even at 400 Hz, which means that the electrical insulation is maintained. According to, the sample manufactured in Example 1 was subjected to a flexural strength (TRS) after heat treatment in air at 50 ° C for% minutes. The flexural strength (plus darkening system root, SQ 3995_ test. Figure 丨 shows in Flexural strength at different density levels. Note that I, even at the same extrusion density, the strength of the material according to the invention may be unexpectedly higher. Example 2 Iron-based powders with particles It has an average particle size of more than 212 micrometers. A highly pure hydration solution is provided with a thin insulating coating and O: \ 90 \ 90403.DOC -16-1229018 meters' are respectively G.1% and G. 2% of hexadecyl hexamethyl silane (hexadecyl seven ismethoxyl silane)-starting treatment, according to the procedure of Example 1. Use the same iron-based powder without any lubricant as a reference. A cylindrical sample with a diameter of 25 mm and a height of 4 mm was compacted with a uniaxial compression action under a compression pressure of 100 MPa. Table 2 shows the injection energy required to inject these compositions and the obtained Embryo Density 1 output energy is used for injection on samples without lubricant The percentage of the amount expressed.

Is 48 Surface moving light ----- --Seizure Good good density (g / cm3)-7M T67 Ύμ 2 Table 2 shows that by adding a small amount of organic_metal haze d 'according to the present invention, the energy required for emission Lowered a lot and the surface finish was improved. It can also be observed that an increase in the weight percentage of the lubricant from Qi% to New Zealand has a positive effect on the injected energy. Example 3 This example shows the effect on the lubricating properties when the bond length of an unhydrolyzed group or an organic-metal compound group is ㈣ μ㈣. In this example, Lao Ao uses a variety of types and quantities of sulphur-methyloxy (Central atomic stone) as a slip agent. Use two types of high-purity, hydrated, iron-based powders that are provided with a thin insulating coating and have two sub-size distributions. The influence of the sub-size ° S powder has about ㈣ particles less than 45 calories and weight The average particle size is about _ microns. There is obviously a coarser particle size distribution at 0: ^ 0 \ 9〇4〇3 D〇c -17-1229018, with a weight average size of about 250 microns and less than 3% and less than 106 microns. Five different types (AE) of organic-silane are used: A methyl-trimethoxy silane B propyl-trimethoxy silane C octyl-trimethyl Octyl-trimethoxy silane D hexadecyl-trimethoxy silane E polyethylene scale-trimethoxy silane, poiyethyleneether-trimethoxy silane, with 10 polyethylene Add five different alkyl-alkoxysilanes with an ether group in the range of 0.05 to 3% to the insulating iron-based powder, and extrude the obtained mixture under uniaxial compression at 1 00 million Pa The action squeezes into a small piece of metal with a diameter of 25 mm and a height of 12 mm. At the time of injection, the dynamic injection force 'per unit of moving area is measured' and after injection, the surface of the green embryo is evaluated for polishing and the density is measured, as shown in Table 3 below. O: \ 90 \ 90403 DOC -18- 1229018 Table 3 Powder C Powder C Powder C Powder C Powder S Powder c Powder S Powder C Powder C Silane 0.05% 0.1% 0.2% 0.2% 0.4% 0.4% 1.0% 3.0% A Seizure B seizure C seizure 58 N / mm2 Poor 7.60g / cm3 D 89 N / mm2 Poor 7.70 g / cm3 69 N / mm2 OK 7.70 g / cm3 38 N / mm2 OK 7.68 g / cm3 63 N / mm2 Poor 7.65 g / cm3 47 N / mm2 OK 7.57 g / cm3 54 N / mm2 OK 7.54 g / cm3 E 80 N / mm2 poor 7.70 g / cm3 35 N / mm2 OK 7.69 g / cm3 75 N / mm2 poor 7.64 g / cm3 32 N / mm2 OK 7.59 g / cm3 49 N / mm2 OK 7.60 g / cm3 As can be seen from Table 3, a chain length of less than 8 carbon atoms in the alkyl chain will not bring satisfactory results, even if The amount added is high. Therefore, at least 8 atoms are required in the lubricant (alkyl, or polyvinyl ether) chain group or plural groups to successfully eject the composition. The amount of salt added more than 5% is less interesting because it will negatively affect the density of raw embryo composition. The table also shows that when the organic-silane content is less than 0.05%, it is impossible for the silane "D" containing 16 atoms in the lubricating alkyl group to be injected without damaging the composition and the die surface. of. However, the configuration of the composition and the quality of the tool have a considerable influence on the surface state after the composition is ejected. Therefore, the amount of lubricant below 0.05%, optionally mixed with conventionally used, i.e., specific lubricants, may be of interest for some applications. Example 4 O: \ 90 \ 90403 DOC -19-1229018 This example shows the lubricating effect of organic-metal compounds with different central atoms. In this example, the lubrication effects of four different reagents, namely silane, titanate, zirconate, and aluminate, were tested with silicon, titanium, zirconium, and shoals as the central atoms, respectively. Various atomic atoms have different coordination numbers and chemical properties. However, 'the chemical structure of the organic-metal compound is selected so that the bond length of the (specific) / slip group or group (R2) exhibits comparable characteristics, which can be compared with the use of hexadecyl-trimethoxylithium Compared with those obtained by burning (hexadecyMrimethoxy silane) (D). A high-purity moisture-containing iron-based powder having a thin insulating coating is treated with each organic-metal compound of 0.2% by weight as a lubricant. The obtained mixture was compacted into a small piece of metal having a diameter of 25 mm and a height of 12 mm under a pressure of 1 100 million Pa by a uniaxial pressing operation. At the time of injection ', the measurement of the dynamic injection force per unit of moving area is performed, and after the injection', the surface of the green embryo is polished and the density is measured, as shown in Table 4 below. Testing of four different types of organic-metal reagents (AD): A isopropyl-triisostearyl titanate (iS〇pr〇pyl_triis〇stear〇yi titanate) B neopentyl (dipropyl) Neopentyl (diallyl) oxy-trineodecanoyl zircon ate C diisobutyl (oleyl) aceto-acetyl aluminate D hexadecyl-trimethoxy silane O: \ 90 \ 90403.DOC -20- 1229018 Table 4

OK ^ Quality :: It can be seen in Table 4 that the properties are all good _ + The type of central atom has only a small influence on the turbidity characteristics. ^ Wind = chain length of hydrolysable group or multiple groups, and to some extent < The structure provides lubricating characteristics according to the present invention. Example 5-The effect of average particle size and particle size distribution was studied in one step. Phases 5 and 3 are used to prepare three different high-purity nr powders with different particle size distributions, all of which are made of thin electrical materials mainly based on ㈣s. All samples were processed according to the present invention, with the same weight percentage of 0.2% hexadecyl-trimethoxylithium, according to the procedure described in the example. . Under the compaction pressure of megapascals, a cylindrical sample with a diameter of 25 micrometers and a weight of 50 grams was compacted under a uniaxial pressing action. The density of the raw embryos of all the samples obtained was higher than 7.6 grams per cubic centimeter.

: Higher lubricant quantity improves surface polishing

O: \ 90 \ 90403.DOC -21-1229018 Obviously, the surface polishing of sample C is better than that of samples A and B, respectively. Example 6 This male example shows the importance of inorganic insulators. A high-purity iron powder whose particles are electrically insulated with a thin phosphate-containing barrier is compared with a powder that is the same but does not have the phosphate-containing inorganic insulator. Both types of powders were then processed according to the present invention with hexadecyl-tdmethoxy Siiane as a lubricant in a weight percentage of 0.2%. In a single step, a ring with an inner diameter of 45 mm and an outer diameter of 55 mm and a height of 5 * m was pressed uniaxially under a compression pressure of π megapascal. After pressing, the parts are placed at 500. Heat treatment in air for 30 minutes. The resistivity was measured using a four-point method. Table 6 below shows the resistivity and density of the composite composition with and without insulating particles prepared. Table 6 Resistivity (// ohm * m) Density (g / cm3) According to the present invention 150 7.68 than the car parent's example 0.5 7.68 [Simplified description of the figure] Figure 1 shows the flexural resistance at different density levels.

O: \ 90 \ 90403.DOC -22-

Claims (1)

1229018 The scope of patent application: 1. A ferromagnetic powder composition containing soft magnetic iron-based core particles, wherein the surface of these core particles is surrounded by an insulating inorganic coating, and a number of systems are sufficient to produce a lubricating effect. A group of compounds consisting of silanes, titanates, aluminaies, hammer esters, and mixtures thereof. 2. The composition according to item 丄 of the patent application scope, wherein the compound has at least one hydrolyzable group and at least one lubricating organic molecular group. 3. For example, the composition in the 15th and the 2nd of the scope of application for a patent, wherein the compound exists as a lubricating layer on the insulating particles. 4. The composition of item _ in the scope of patent application, wherein the compound has the following general formula: and the wrong central atom; M (Ri) n (R2) m, where M is a series selected from silicon, titanium, and aluminum R1 series A hydrolyzable group; R 2-a functional group consisting of a lubricating organic molecular group, where the sum of m + η is the coordination number of the # 11 central atom; η is an integer of -1, and m is an integer of -1. 5. Where R! Is an alkoxy group having less than 12 and less than 3 carbon atoms, wherein I is a clamp group such as the composition in the scope of patent application No. 4, preferably less than 6, and most preferably foundation. 6 · If you apply for the composition in the scope of the fourth item (chelate group) ° O: \ 90 \ 90403.DOC 1229018 7. If you apply for the composition in the scope of the 6th aspect of the patent, the sweetener is hydroxyacetic acid (hydr 〇Xacetic acid) (— 〇 (〇 = 〇) — cH2〇) or ethylene glycol (-OHCH2CH2〇-) residues. 8. If the composition of the scope of application for item 4 of the patent application, the medium contains 10-24 carbon atoms of 6-30 carbon atoms, and optionally contains one or more nitrogen atoms selected from the group consisting of nitrogen , Oxygen, sulfur, and heteroatoms in groups. 9. The composition according to item 8 of the application, wherein the chemical group is linear, branched, cyclic, or aromatic. 10. The composition according to item 8 of the scope of patent application, wherein the & 2 group is selected from the group consisting of alkyl, ether, ester, phospho-alkyl, Chains of a group consisting of scales, phosph-lipid, and phospho-amine. 11. The composition as claimed in claim 10, wherein the 1 is selected from the group consisting of phosphato, pyrophosphate Sphat〇, and phosphito . 1 2 · The composition according to item 1 or 2 of the scope of patent application, wherein the compound is selected from the group consisting of alky l-aikoxy silanes and polyether-alkoxy silanes). 1 3 · The composition according to item 1 or 2 of the scope of patent application, wherein the compound is selected from the group consisting of octyl-trimethoxy silane, hexadecyl-hexadecyl -trimethoxy silane), polyethylene-trimethoxy silane, isopropyl-triisostearyl titanate, isopropyl-tri (dioctyl) Titanate O: \ 90 \ 90403.DOC -2- 1229018 (isopropyl-tri (dioctyl) phosphato titanate), neopentyl (dipropenyl) oxy-trineodecanylglycerate g purpose ( neopentyl (diallyl) oxy-trineodecanoyl zirconate), neopentyl (dipropenyl) oxy-tris (dioctyl) phosphate ester (neopentyl (diallyl) oxy-tri (dioctyl) phosphato zirconate) Diisobutyl-acetoacetyl aluminate 〇14. The composition as claimed in claim 1 or 2, wherein the iron-based particles of the inorganic inorganic coating are based on Scale-based. 15 · The composition according to item 1 or 2 of the scope of patent application, wherein the iron-based core particles are basically composed of pure iron. 16. If the composition according to item 1 or 2 of the scope of patent application, wherein the iron-based core particles have a size of less than 5%, the size is less than 45 microns. 17. The composition according to item 1 of the Shen-Ken patent, wherein at least 60% and preferably at least 60% of the iron-based core particles are composed of particles having a particle size greater than about 106 microns. 1 8. The powder composition according to item i or 2 of the scope of patent application, wherein at least preferably at least 40% 'and more preferably at least 6. % Of the iron-based: core particles are composed of particles with a particle size greater than about 212 microns. K-type composition, which comprises the compound as described in item _ of the scope of the patent application, the compound is in a percentage by weight of 0.05_0%, preferably 0.07-0.45%, and most preferably 804% was present. The composition of the patent application No. lsiU is selectively mixed with an oral agent, such as a specific lubricant, adhesive, or flow enhancement. O: \ 90 \ 90403.DOC 1229018 (flow-enhancing agents). 21. 22. 23. A method for preparing a soft magnetic composite material having a density of at least 7.45 g / cm3, comprising the steps of:-providing an iron or iron-based material such as the scope of patent application item 1 or 2 Powder composition;-a soft magnetic powder composition obtained by uniaxial compaction in a die at a compaction pressure of at least about 800 million Pascals (MPa); and-ejecting the green body from the compaction tool ; And-selectively heat treating the compacting body. For example, the method of claim 21 in the patent scope, wherein the compaction is performed under a pressure of at least about 900 million Pascals, more preferably at least 1,000 million Pascals, and preferably higher than 1100 million Pascals. . Leiyue Patent | (L method of item 21 or 22, wherein the particle size of the iron core powder is the size as defined in item 16 of the scope of the patent application. O: \ 90 \ 90403.DOC