56 results about "Sendust" patented technology

The anti electromagnetic interference material is composed of several layers: the impedance matching layer is made of absorbing type sendust powder, manganese-zinc ferrite and resin; the absorbing layer is made of absorbing type sendust powder, nickel zinc ferrite and resin; the reflecting layer is made of reflection type sendust powder, iron powder and resin.

The invention belongs to the preparation field of a magnetic material, and particularly relates to composite magnetic powder and a preparation method therefor. The preparation method comprises the following steps of a), preparing an iron-silicon-aluminum alloy (which also can be called as sendust in the specification) thin belt by a melt rapid quenching method; in the preparation process, applying a directional magnetic field in belt-spinning; and performing crushing on the prepared iron-silicon-aluminum alloy thin belt to obtain an iron-silicon-aluminum alloy fragment; b), enabling the iron-silicon-aluminum alloy fragment and ferrite powder to be mixed and ball grinded to obtain composite magnetic powder; and c), enabling a binder, a lubricating agent and the composite magnetic powder to be mixed and pressed in sequence to obtain a composite magnetic powder core. Experiment results prove that the effective magnetic conductivity of the magnetic powder core prepared by the method can be higher than 40 at the test frequency of 100kHz; and the loss is lower than 83W/kg in the test conditions of 100kHz when Bm is equal to 300mT.

The invention discloses a preparation method of a sendust core with a high direct current bias characteristic. The preparation method comprises the following steps of (1) core powder preparation, (2) passivating treatment, (3) compression moulding and (4) heat treatment, wherein low-hardness plastic metal powder is mixed into sendust in Step (1); a passivant is added to the prepared core powder for the passivating treatment in Step (2); an adhesive agent, an insulating agent and a lubricant are successively added to the mixed metal powder subjected to the passivating treatment, and then the compression moulding is conducted in Step (3); and annealing treatment is conducted on the sendust core subjected to compression moulding at 600-700 DEGC for 0.5-2h in Step (4). The preparation method has the benefits that the core powder formula is improved, the density of the sendust core is increased and the uniformity of air gap distribution is improved, so that the direct current bias characteristic of the sendust core is improved, and the problem that the conventional sendust core cannot work under the condition of low loss and high direct current bias characteristics is solved.

A metallic magnetic material for magnetic element for magnetic element of a choke coil and an SMD choke power coil for accommodating low voltage and high current in a personal computer, graphic card, high frequency power supply, etc, is prepared by baking a powder of Fe—Si—Al alloy sendust, obtained by an atomization process and having an average particle diameter of 10 to 70 μm, at 600° C. to 1000° C. in air or in an oxidizing atmosphere and mixing the baked sendust with 3 to 45 wt % of a carbonyl iron powder with an average particle diameter of 1 to 10 μm. The metallic magnetic material for magnetic element according to the present invention is used in a coil-embedded SMD power choke coil having a square or rectangular shape with a height of 1 mm to 7 mm and with a length of one side being 3 mm to 13 mm.

The invention provides a method for manufacturing mu-90 sendust magnetic powder cores, which comprises the steps of smelting, coarse crushing, heat treatment, fine crushing, annealing treatment, powder grading, powder insulation, compression molding, secondary heat treatment and coating treatment. The mu-90 sendust magnetic powder cores comprise binary iron-silicon alloy with added aluminum, wherein the silicon content accounts for 9-10%, the aluminum content accounts for 5-6%, and the balance is iron. The smelting temperature is 1600 DEG C. The compression molding pressure is 1900 MPa. The heat treatment temperature is 600-800 DEG C, the holding time is 1 hour, and the nitrogen-oxygen mixed atmosphere is adopted. When f=10 kHz and B=1 mT, mu=90+/-7.2; when f=50 kHz and B=50 mT, the volume ratio loss Pcv<=100mW/cm3. When an additional direct current bias magnetic field is 100 Oe, the change rate of the magnetic conductivity is not greater than 75%. The method for manufacturing the mu-90 sendust cores has the advantages that an added bonding agent is a solid inorganic bonding agent, the heat treatment after the molding is performed in the nitrogen-oxygen mixed atmosphere environment and subjected to heat preservation for 1 hour. Prepared magnetic powder cores are not prone to pulverize, high in strength and stable in performance and have good direct current biasing characteristic, frequency stabilization characteristic and low loss.

The invention discloses a method for manufacturing a sendust material and a mu173 sendust magnetic powder core. The specific method includes the steps of a, conducting alloy smelting, wherein the smelting temperature is more than 1400 DEG C, and the time for alloy smelting is more than 50 minutes; b, preparing powder, namely, directly conducting nitrogen spraying to manufacture powder after the alloy smelting is conducted; c, conducting powder reduction, namely, conducting reduction through nitrogen; d, conducting power material inactivation, namely, adding an analysis pure grade phosphoric acid solution to the sendust powder, and conducting uniform mixing, wherein the analysis pure grade phosphoric acid solution accounts for, by weight, 3% to 5% of the sendust powder; e, conducting annealing, namely, placing powder into a nitrogen protection furnace at the temperature of 360+/-30 DEG C; f, conducting insulation coating, namely, adding silicon resin adhesives and powder lubricants, wherein the silicon resin adhesives account for, by weight, 1.5% to 3.5% of the powder, and the powder lubricants account for, by weight, 0.5% to 1% of the powder; g, conducting die pressing forming; h, conducting thermal treatment, namely, placing a formed product into the nitrogen protection furnace at the temperature of 700+/-30 DEG C, and conducting annealing for about one hour; i, conducting surface coating, namely, evenly spray painting a layer of epoxy resin paint on the outer surface of the product.

The invention discloses a preparation method of a low-loss high-superposition sendust material with magnetic conductivity mu equal to 26. The method comprises the steps of performing batching, phosphatization and primary annealing, adding an appropriate high-temperature resistant insulating material, performing compression molding and secondary annealing, and then performing appropriate insulating coating. According to the method, the loss of a magnetic core prepared from the sendust material with the magnetic conductivity mu equal to 26 is 500mW/cm3 at 100K/100mT; and the superposition property is 100Oe:85% and 50Oe:95%. The method has the benefits that the loss of the sendust material is reduced by 100-300mW/cm3 compared with that of other sendust materials of the same kind; and the superposition property is improved by 10% compared with that of the sendust materials of the same kind, reaches an iron silicon level and is approximate to the level of high-flux iron nickel.

The invention discloses a method for manufacturing a [mu]26 composite magnetic powder core. The technical scheme is as follows: after two or more alloy powders from mechanically crushed sendust, aerosolized sendust, aerosolized iron-silicon, aerosolized iron-nickel and aerosolized iron-nickel-molybdenum are selected and are fully mixed, phosphoric acid passivation treatment and drying are performed, then one or more from silicon oxide, aluminum oxide, calcium oxide and magnesia calcinata, sodium silicate, and deionized water are successively added to the alloy powders subjected to the passivation processing and drying for insulation coating, and afterwards, the [mu]26 composite magnetic powder core is prepared after press molding, heat treatment and surface coating. The alloy powders used in the method have the advantages of mature technology, stable performance and relatively low cost so that the prepared magnetic powder core has quite high cost performance and stability. Such oxides as the silicon oxide, the aluminum oxide, the magnesia calcinata and the like and such inorganic materials as the sodium silicate and the like are used for coating adhesion so that the obtained composite magnetic powder core has the advantages of high stability, high reliability, low cost, high safety and facilitated production.

The invention relates to a method for manufacturing mu 125 sendust cores. The method comprises the steps of alloy smelting, coarse crushing, heat treatment, fine crushing, annealing treatment, powder classification, powder insulation, compression moulding, secondary heat treatment and coating treatment. The mu 125 sendust cores comprise the following compositions: 9.10 percent of silicon, 5.95 percent of aluminum and the balance of iron; the sendust cores are smelted at 1,600DEG C, molded under the pressure of between 1,950 and 2,150MPa, subjected to heat treatment at the temperature of between 600 and 800DEG C, kept at the temperature for 30min, and subjected to heat treatment under the protection of nitrogen. The magnetic permeability mu of the sendust cores is equal to 125+/-10 (10kHz/1mT); the mu change rate in 1 MHz is less than 5%; Pcv is less than or equal to 190 mW/cm<3> (100kHz/50mT); and the applied direct current bias field H is not less than 390e when the mu is 50%. A passivating solution does not contain chromium ions, which is environment-friendly; and an insulation layer between powder of the sendust cores has a glass phase structure containing P, which has high temperature for heat treatment and contributes to eliminating internal stress and reducing iron loss. A solid inorganic binder is adopted, so the adhesive strength is high, the performance is stable, and the process is simplified.

The invention provides a sendust alloy magnetic powder core preparation method. The method includes: step one, preparing alloy powder, to be more specific, subjecting metal raw materials including aluminum, silicon, nickel and iron to metal smelting to obtain alloy melt, and preparing the alloy melt into alloy powder according to a gas atomization method; step two, insulation coating treatment ofthe alloy powder; step three, magnetic powder core spraying insulating treatment. By direct preparation of the super sendust alloy powder according to the gas atomization method, production proceduresare reduced, stress caused by shaping processes including crushing, ball milling and the like is eliminated, the oxygen content of a prepared sendust alloy magnetic powder core is reduced, and magnetic performances of the sendust alloy magnetic powder core are improved. In addition, by insulation coating treatment of the alloy powder, a super sendust alloy powder core appropriate in magnetic conductivity and low in loss can be obtained.

The invention relates to an electromagnetic screen mobile phone and a soft magnetic material piece applied to the same. The soft magnetic material piece is made of Sendust magnetic powders. The Sendust magnetic powders comprise components of, by weight, 9.2%-9.8% of silicon, 5.3%-5.9% of aluminum, less than 0.02% of carbon, less than 0.8% of manganese, less than 0.006% of sulphur, less than 0.01% of phosphorus and less than 1.15% of oxygen, with the balance being iron. The thickness of the soft magnetic material piece is 0.9-1.5 mm. A user can apply the soft magnetic material piece to the electromagnetic screen mobile phone to solve the problem of soft magnetic compatibility in the prior art and to ensure that an electromagnetic screen causes no interference in neighboring magneto-sensitive elements such as an electronic compass, namely, a geomagnetic sensor, and meanwhile to guarantee that the radio frequency index of the electromagnetic screen cannot reduce. Besides, a GSM (Global System for Mobile Communications) interference problem can be solved, the electromagnetic screen is free from influences of GSM radiant power and movement track signals of an electromagnetic pen can be sensitively and accurately received.

The present invention provides a novel complex thermal insulation and heat preservation structure, the structure has from inside to outside a subbase, a thermal insulation and heat preservation layer, a strengthening and crack-resistant layer, a thermal reflecting decorative layer. The thermal insulation and heat preservation layer is formed with complex powder material A and polystyrene bubble particle B, the complex powder material A has 50-80% concrete, 10-40% sendust glass hollow ball material having specific surface area of 400-5000 m[2]/kg, air entraining agent 0.005-0.05%, modifying agent 1-5%, water reducing agent 0.2-1.2%, fiber 0.1-5%, tackifier 0.5-2%, the strengthening and crack-resistant layer is coagulated with thermal galvanization steel wire net and modifying crack-resistant base body of fiber strengthening polymer, the wire net is hung and fixed on the thermal insulation and heat preservation layer with plastic expanding bolt, the thermal reflecting decorative layer is made of tint glazed ceramic wall tile or glass, aluminium alloy, stainless steel curtain wall material. The structure apparently improves the thermal insulation and heat preservation ability, and effectively resolves the problem of crack, gaul, and drop of the tile, also greatly improves the wear ability and construction efficiency.

The invention relates to a sendust powder integrated pressing inductor and a production process thereof and belongs to the technical field of the production of inductors. According to the sendust powder integrated suppression inductor and the production process thereof, a red copper band is used as a coil, the middle portion of the red copper band is wrapped in a sendust block, the exposed portions at both ends are bent downwards along the side of the sendust block and bent inwards at the bottom of the sendust block, and a cover sheet is connected with the upper surface of the sendust block through gelatinous materials. The production process includes the steps of forming a blank through pressing, sintering heat treatment, electro plating nickel and tin, cutting and bending, adhering cover sheet and obtaining sendust powder integrated pressing inductor. The sendust powder integrated pressing inductor and the production process thereof have the advantages of being less in iron loss and good in formability, saving space, reducing noise and having stable and reliable electromagnetic performance, and meanwhile improve the production efficiency and reduce the production costs.

The invention relates to the technical field of electromagnetic wave absorption, and provides a preparation method of a sendust electromagnetic wave absorbent. The preparation method comprises the steps: manganese zinc ferrite and sendust alloy powder are mixed to be ball-milled, wherein the ratio of milled materials to milling media is 1:(14 to 16), and ball milling is conducted for 5-50 h; and then drying is conducted to obtain the sendust electromagnetic wave absorbent, wherein the manganese zinc ferrite accounts for 0.5-5at% of the sendust electromagnetic wave absorbent, and the manganesezinc ferrite is prepared from the components in percentage by atom: 52-55% of Fe2O3, 33-36% of MnO and 10-14% of ZnO. According to the preparation method, the manganese zinc ferrite is doped in the sendust alloy powder with the reasonable content, and the reasonable ball milling time is selected in the mixed ball milling process of the manganese zinc ferrite and the sendust alloy powder, so that the prepared sendust electromagnetic wave absorbent has a good absorption effect on electromagnetic waves. The invention further provides the sendust electromagnetic wave absorbent prepared through thepreparation method. The sendust electromagnetic wave absorbent has good absorption performance on the electromagnetic waves.

The invention provides a magnetic metal powder with high forming density, low molding pressure and surface insulation. The powder manufactured through the method has three layers of structures from inside to outside. An innermost material is magnetic metal or an alloy powder with Vickers hardness which is greater than or equal to 800 and is a source of a magnetic property of a metal powder core; asecond layer material is a relatively soft metal or an alloy film with the Vickers hardness which is less than or equal to 400 and achieves the effect of reducing a stress during a powder molding process; and an outermost layer material is an insulating layer formed by an inorganic non-metal material. In addition, the metal powder core manufactured through using the powder has a small residual stress, high powder core density and small molding pressure so that the metal powder core has low losses and high magnetic permeability. The composite structure magnetic powder is suitable for manufacturing the metal powder of the magnetic metal powder which has high hardness and is difficult to deform, such as a Sendust alloy powder, an amorphous soft magnetic metal powder, a nanocrystalline alloypowder and the like. The molding pressure and the residual stress can be significantly reduced during a molding process. Powder core density is increased and finally the performance of the metal powder core is improved.

The invention discloses a method for producing ferrosilicon alloy by carbon reduction from aluminum-silicon-iron mixed ore. The method utilizes the continuous supply of powdery raw materials and the continuous supply of reducing gas to reduce the need for multiple equipment to cooperate in industrial production. To complete the production, while reducing production costs. The present invention adopts the combination of pulverizer and flash suspension furnace on production equipment, and the whole processing time from raw material entering to ferrosilicon alloy production is 20 minutes to 40 minutes, which improves production efficiency and recovery rate.