77 results about "Residual magnetization" patented technology

The invention belongs to the technical field of geophysics, and particularly discloses a magnetization intensity vector sparse inversion method under a strong residual magnetism condition. The method comprises the following steps: firstly, subdividing an underground space, and simulating an underground magnetic anomalous body; obtaining a sensitivity matrix according to partial derivatives of observed magnetic anomaly values of the magnetic anomaly body in each unit magnetization direction, and constructing a total objective function of magnetization intensity vector inversion based on the sensitivity matrix; taking magnetization intensity amplitude as a parameter to introduce sparse constraint for the total objective function; converting the total target function into a standard L2 regularization form, and calculating a sensitivity matrix by using a singular value analysis method so as to obtain target parameters of the total target function; and finally, obtaining three components of the magnetization intensity vector from the target parameters, and further solving the magnetization intensity amplitude and the total magnetization direction. According to the scheme, the magnetization intensity inversion precision under the influence of strong residual magnetization is effectively improved.

The invention discloses auxiliary alloy nano powder, modified magnetic powder, a sintered neodymium-iron-boron magnet and a preparation method. According to the preparation method of the auxiliary alloy nanopowder for modifying the magnetic powder, the chemical component of the auxiliary alloy nanopowder is Re100-m-n (Cu, X) mQn, Re is a light rare earth element, X is selected from at least one of Al, Ga, Co, Mg, Sn, Te and Sb, and Q is selected from at least one of Ti, Zr, Hf, V, Nb, Ta, W and Mo; m and n are atomic numbers respectively, m is greater than or equal to 24 and less than or equal to 72.4, n is greater than or equal to 12.5 and less than or equal to 76, and 100-m-n is greater than or equal to 0; the auxiliary alloy nano powder does not contain Fe and B; the preparation method comprises the following steps: (1) providing an auxiliary alloy sheet; and (2) mixing the auxiliary alloy sheet, a modified substance and an organic solvent, and carrying out primary crushing and fine crushing to obtain the auxiliary alloy nano powder. The coercive force and the squareness of the sintered neodymium-iron-boron magnet can be improved, and the absolute value of the residual magnetism temperature coefficient and the absolute value of the coercive force temperature coefficient of the sintered neodymium-iron-boron magnet are reduced.

The invention discloses a magnetizing inrush current suppression method and system during closing of a distribution transformer. The method comprises the following steps: acquiring three-phase voltage and current waveform data before and after tripping of a primary side circuit breaker of the distribution transformer; measuring and calculating the residual magnetism of the primary side winding according to the voltage and current data, and determining a closing phase sequence by the minimum residual magnetism in order to avoid dispersive errors of the circuit breaker; determining the specific closing time of the transformer according to the residual magnetism information; only the voltage and current waveform data before and after the primary side circuit breaker is switched on need to be collected, the residual magnetism is measured and calculated, and the switching-on phase sequence and the switching-on time of the circuit breaker are determined, so that the magnetizing inrush current during switching-on of the distribution transformer is inhibited. According to the method, the actual condition of the power distribution network is fully considered, parameters are easy to obtain, the operation is completed within a period after the inherent closing time of the circuit breaker, the speed is high, the principle is deeper, the closing phase sequence and strategy are clear, operability is high, and the method is suitable for various scenes of the power distribution network.

The invention discloses a method for preparing (SmxY1-x) Co5 rare earth magnetic particles with high magnetic properties by a chemical method, and belongs to the field of rare earth magnetic materials. The invention particularly relates to a novel technology for preparing (SmxY1-x) Co5 ternary alloy magnetic powder with high magnetic properties by combining chemical liquid phase synthesis with calcium reduction reaction. A Sm (OH) 3 / Y (OH) 3 / Co (OH) 2 (at) Ca (OH) 2 crystalline state mixed precursor prepared by chemical coprecipitation and a hydrothermal reaction is uniformly subjected to a complete calcium reduction reaction with a certain amount of metal calcium particles, KCl and CaCl2 diffusion media in an argon atmosphere, and the magnetic powder is prepared. The saturation magnetization intensity and the residual magnetization intensity of the magnetic powder are improved by doping the yttrium element, but the coercive force of the magnetic powder is slightly reduced, and the method provides a new thought for preparing high-performance rare earth magnetic particles.

The invention belongs to the field of magnetic materials, particularly relates to a high-power garnet ferrite and a preparation method thereof, and provides a high-power garnet ferrite and a preparation method thereof aiming at the defects that high residual magnetism ratio, low resonance line width, high spin wave line width and high Curie temperature of the garnet ferrite in the prior art are difficult to consider at the same time, and the high-power garnet ferrite is obtained through Co < 2 + >-Ge < 4 + > or Co < 2 + >-Si < 4 + > ion combined substitution. The garnet ferrite with high remanence ratio, low resonance line width, high spin wave line width and high Curie temperature can be obtained by reasonably designing the doping amount of Co < 2 + > ions and Mn < 3 + > ions and matching with proper Dy < 3 + > doping. Aiming at the defect that low resonance line width, high spin wave line width and high Curie temperature of garnet ferrite are difficult to consider at the same time, the invention provides a Co < 2 + > ion and Dy < 3 + > ion combined substitution method, so that the garnet ferrite can have low resonance line width, high spin wave line width and high Curie temperature at the same time.

[Object] To provide a Peltier element with an ultra-low thermal resistance heat flux sensor that is capable of detecting heat flow passing through the Peltier element at high speed and has negligible thermal resistance.[Solving Means] It has a structure in which an anomalous Nernst heat flux sensor 20 is formed directly on one or both of an upper part and a lower part of an insulating board that forms a Peltier element 10. The present invention is favorably characterized in that each fine line (22a) of a thermoelectric generator is formed of a magnetic material having residual magnetization even in absence of an external magnetic field and is magnetized in a direction orthogonal to a length direction of the fine line, and each fine line (23a) of a connector is formed of a ferromagnetic material that is magnetized in a direction opposite to a direction in which each fine line (22a) is magnetized, a magnetic material having a Nernst coefficient with an opposite sign to that of each fine line (22a), or a non-magnetic material.

The utility model discloses a pipeline stress internal detection probe which is characterized in that the pipeline stress internal detection probe comprises a pair of L-shaped magnetic cores, two excitation coils are respectively wound on the pair of L-shaped magnetic cores along the same direction, the excitation coils are connected with a driving circuit, and when current i in the same direction is conducted in the excitation coils through the driving circuit, the excitation coils are connected with the driving circuit. A uniform magnetic field area is formed near the distance l between the two magnet exciting coils, and a plurality of magnetic sensors are arranged in the uniform magnetic field area. According to the utility model, the pulse excitation coil is used as a low-frequency pulse magnetic field generating device to magnetize the ferromagnetic pipeline. After the pipeline is magnetized, if an external magnetic field disappears (is reduced to zero), the pipe wall still shows magnetism, and the residual magnetization intensity of the pipe wall at the moment is called residual magnetism. The stress can change the residual magnetization intensity of the ferromagnetic material, so that the internal magnetic conductivity of the material can be changed. Therefore, the residual magnetization is measured through the magnetic sensor integrated in the probe, the stress is represented, and stress detection and analysis are realized.

This application relates to the field of LNG cryogenic pressure vessel welding technology, specifically disclosing a multi-level collaborative control method for magnetic blow in 7Ni steel welding based on a quantified remanent magnetization threshold. Addressing the problems of severe magnetic blow and poor all-position welding stability caused by the high permeability, high coercivity, and difficulty in demagnetizing 7Ni steel, the method uses a remanent magnetization threshold of ≤50Gs to construct a collaborative control system encompassing pre-welding quantitative management, welding polarity and ground wire optimization, welding parameter and sequence constraints, real-time monitoring and automatic demagnetization closed-loop during welding, and post-weld quality verification. This application can effectively suppress all-position magnetic blow, avoiding defects such as arc deviation, incomplete penetration, slag inclusion, and porosity; achieving a first-pass yield of ≥97.5% for the main weld of the LNG storage tank, with a joint impact energy of ≥80J at -196℃ and a hardness of ≤300HV10, meeting cryogenic service specifications and applicable to the industrial welding production of large 7Ni steel LNG storage tanks.

A passive magnetic bearing assembly (10) for a vacuum pump and a vacuum pump having such a bearing are disclosed. The invention relates to a passive magnetic bearing assembly having a plurality of pairs of ring magnets (20, 30) arranged in a stack, one of the ring magnet pairs being arranged on a stator side (4) of the bearing and the other of the ring magnet pairs being arranged on a rotor side (2). The ring magnets are radially magnetized and each rotor ring magnet comprises at least a first harmonic of magnetic inhomogeneity, where the magnetic inhomogeneity is measured as a ratio between a 0-peak variation of remanence [Delta] Bi and an average remanence BR0, the first harmonic of magnetic inhomogeneity being less than 3%.

To provide magnetic powder having a narrow particle size distribution and having high residual magnetization, and a method for producing the same.SOLUTION: A method for producing anisotropic magnetic powder comprises: a pretreatment step in which an oxide comprising Sm and Fe is heat-treated in a reducing gas-containing atmosphere to obtain a partial oxide; a step in which the partial oxide is heat-treated in the presence of a reducer to obtain alloy particles; and a step in which the alloy particles are heat-treated at a first temperature of 400°C or more to 470°C or less in a nitrogen or ammonia-containing atmosphere and is thereafter heat-treated at a second temperature of 480°C or more to 610°C or less to obtain a nitride.SELECTED DRAWING: None

The invention discloses an oil and gas pipeline internal detection device and method based on the coupling effect of residual magnetism and eddy current, and relates to the technical field of pipeline internal detection. A magnetization node is used to perform saturation magnetization on the pipeline to be detected. When the magnetization node stops magnetizing, the magnetization intensity of the pipeline to be detected decreases from the saturation magnetization intensity to the residual magnetization intensity, and is in a residual magnetization state. An induced eddy current field is generated in the pipeline to be detected by the detection node. The defects of the pipeline to be detected are detected based on the coupled magnetic field formed by the residual magnetization intensity and the induced eddy current field. By magnetizing the pipeline to be detected to the magnetic saturation state, the uneven distribution of the relative magnetic permeability of the pipeline can be eliminated, and the probability of missed detection and false detection of pipeline defects caused by the uneven relative magnetic permeability can be reduced. At the same time, the skin effect of the eddy current detection technology can be suppressed, and the effective detection of internal and external surface defects can be realized. The detection node can obtain the composite signal of residual magnetism and eddy current, and the sensitivity of defect perception is improved, thereby improving the eddy current perception ability based on the residual magnetism effect.

The present application provides a magnetic layer having a coercive force Hc of 2.00 kOe or more and a residual magnetization Mrt per unit area of 2.00 memu / cm2 or more, which is achieved without using a non-magnetic underlayer for promoting in-plane orientation of the magnetic layer and without performing heat deposition 2 The above in-plane magnetization film, in-plane magnetization film multilayer structure, hard bias layer, magnetoresistance effect element, and sputtering target. The in-plane magnetization film has: a preliminary magnetic layer (12A) containing Co, Pt, and a non-magnetic grain boundary material and having a thickness of 1 to 32 nm; and a magnetic layer main portion (12B) formed on the preliminary magnetic layer (12A) and containing Co, Pt, and a non-magnetic oxide, the above non-magnetic grain boundary material of the preliminary magnetic layer (12A) containing at least one of a Zn oxide and a Ta oxide.

The invention discloses a magnetic stripe lightning current recording card analysis system and analysis method, the system comprises an upper computer and a computer end which are in electric signal connection, the upper computer comprises an upper computer control module, a card reader, a residual magnetism acquisition module and an AD acquisition module, and the computer end comprises an AD analysis module. The method comprises the following steps: inserting a magnetic strip lightning current recording card into a card reader, collecting and processing residual magnetism in the recording card, outputting a residual magnetism voltage waveform, processing and converting the residual magnetism voltage waveform into an AD waveform, and uploading the AD waveform to an AD analysis module for calculation to obtain an integral area; and calibrating the magnetic strip lightning current recording card to obtain a calibration function, and substituting the integral area into the calibration function to obtain a peak current. According to the invention, through combination of the upper computer system and the computer end system, reading of the magnetic stripe type thunder peak current recording card installed under any cable or structure is realized, the application scenarios of the magnetic stripe type thunder peak current recording card are greatly increased, and the peak current of lightning stroke under different scenarios can be accurately analyzed.

A method of producing a SmFeN-based anisotropic magnetic powder is provided, the method including preparing a SmFeN-based anisotropic magnetic powder before dispersing comprising Sm, Fe, W, and N, and dispersing the SmFeN-based anisotropic magnetic powder before dispersing using a resin-coated metal media or a resin-coated ceramic media to obtain a SmFeN-based anisotropic magnetic powder. Also provided is a SmFeN-based anisotropic magnetic powder comprising Sm, Fe, W, and N and having an average particle size of less than 2.5 μm, a residual magnetization or of not less than 130 emu / g, and an oxygen content of not higher than 0.75% by mass.

A method of producing a SmFeN-based anisotropic magnetic powder is provided, the method including preparing a SmFeN-based anisotropic magnetic powder before dispersing comprising Sm, Fe, W, and N, and dispersing the SmFeN-based anisotropic magnetic powder before dispersing using a resin-coated metal media or a resin-coated ceramic media to obtain a SmFeN-based anisotropic magnetic powder. Also provided is a SmFeN-based anisotropic magnetic powder comprising Sm, Fe, W, and N and having an average particle size of less than 2.5 μm, a residual magnetization σr of not less than 130 emu / g, and an oxygen content of not higher than 0.75% by mass.

The present invention discloses a method and device for charging and demagnetizing a magnetic latching relay with a built-in three-pole magnetic steel. The method performs aging of the three-pole magnetic steel at high temperature, thereby ensuring the residual magnetism stability of the three-pole magnetic steel under high temperature conditions and reducing the possible magnetic pole deviation of the middle magnetic pole of the three-pole magnetic steel under high temperature conditions. The three-pole magnetic steel changes the originally disordered magnetic domain direction in the three-pole magnetic steel under the instantaneous strong magnetic field of the three-pole magnetic field (magnetic poles in opposite directions) so that the residual magnetism is arranged bidirectionally and symmetrically from the central plane of the magnetizing magnetic field and is permanently magnetized, so that the three-pole magnetic steel exhibits three-pole characteristics. Under the condition that the center line of the three-pole magnetic steel is located at the central symmetric plane of the magnetizing and demagnetizing magnetic field and the magnetizing magnetic field strengths on both sides are the same, the middle magnetic pole of the charging and demagnetizing effect is located at the exact center plane of the three-pole magnetic steel and the magnetic induction strengths of the end magnetic poles are the same or the difference is very small.

The invention relates to a pressure sensor using a magnetic field. A pressure sensor using a magnetic field according to the present invention comprises: an elastic part containing a magnetic material having a residual magnetization value; and a circuit unit that generates a Hall voltage when a magnetic field changes, and that senses the magnitude of the Hall voltage corresponding to the change in the magnetic field when the magnetic field applied to the circuit unit changes due to the deformation of at least a portion of the elastic unit based on an external pressure.

To provide an R-T-B-based rare earth magnet achieving both residual magnetization and coercive force.SOLUTION: The present invention relates to an R-T-B-based rare earth magnet in which R is a rare earth element, T is Fe and / or Co, and B is boron. R includes Nd. The R-T-B-based rare earth magnet includes a main phase having an R2T14B-type crystal structure and a grain boundary phase present around the main phase. The average grain size of the main phase is 0.1-1.0 μm. The main phase has a core portion and a shell portion present around the core portion. The ratio (concentration of Nd in shell portion / concentration of Nd in core portion) of the concentration of Nd (atom%) in the shell portion and in the core portion of the main phase is 1.654-1.714.SELECTED DRAWING: Figure 2

The application relates to a residual residual magnetism detection method and a detection device, and belongs to an automatic detection method and equipment. The residual residual magnetism detection method comprises the following steps: placing a detection sample on a conveying mechanism, conveying the detection sample to a detection mechanism through the conveying mechanism; under a zero magnetic environment, the detection mechanism detects the residual residual magnetization of the detection sample; after the detection is completed, the detection sample moves to a belt of a sorting mechanism; and according to the detection result of the detection mechanism, the detection sample is classified through the sorting mechanism. The detection method can detect the residual residual magnetization of parts in a production process and / or after processing is completed, can timely monitor and sort, and is high in detection efficiency and accuracy.

The invention provides an online evaluation method and system for the magnetizing inrush current suppression capability of a transformer, and relates to the technical field of power system operation evaluation, and the method comprises the steps: collecting the fracture voltage data of a primary winding of the transformer, and calculating the initial residual magnetism amount of an iron core through a magnetic flux reconstruction algorithm; an improved harmonic superposition method is adopted to decompose a transformer input transient primary side current waveform, a harmonic component is obtained through screening, and a distortion coefficient of the harmonic component is calculated; substituting the distortion degree coefficient and the initial residual magnetism quantity of the iron core into the established hysteresis loop model to obtain a working point track of the transformer iron core at the moment of input; and based on the dynamic change characteristic of the working point track, the working point track is corrected by combining the micro magnetic conductivity parameter of the iron core material, and an evaluation index of the magnetizing inrush current suppression capability of the transformer is obtained. According to the method, the dynamic characteristics and the nonlinear loss characteristics of the inrush current harmonic waves are quantified, the inrush current risk when the transformer is put into operation is effectively reduced, and the safety and the stability of power system operation are enhanced.

Provided is a magnetic recording medium that is capable of increasing the reproduction output.A magnetic recording medium is a tape-shaped magnetic recording medium and includes a recording layer. A nucleation magnetic field Hn of the magnetic recording medium satisfies a relationship of Hn≥0 [Oe], and the magnetic recording medium satisfies a relationship of the following formula (1).(Mrt)0.5×f⁡(Hs)≥0.7(1)(wherein, in the formula (1), Mrt represents a product of a residual magnetization amount Mr of the magnetic recording medium and a thickness t of the recording layer. Hs represents a saturation magnetic field of the magnetic recording medium. In a case where Hs≤8500 [Oe], f(Hs)=1.00, and in a case where Hs>8500 [Oe], f(Hs)=1 / (1+(Hs−8500) / 8500).).

The present invention discloses a system and method for measuring the remanent magnetism of ferromagnetic materials, belonging to the field of electromagnetic parameter measurement technology. The system includes a fluxgate sensor array, a data integrator, and a host computer; the fluxgate sensor is used to measure the magnetic induction intensity and transmit it to the host computer; the host computer is used to obtain the residual magnetization intensity matrix and the magnetic induction intensity matrix, thereby calculating the conversion matrix, and combining the uniqueness of the conversion matrix to verify the uniqueness of the remanent magnetization intensity of the desired ferromagnetic material; under the premise that the geomagnetic field can be ignored, according to the constitutive relationship B=μ0(H+M), the magnitude and direction of the remanent magnetization component of the material can be obtained and displayed in real time from the remanent magnetization intensity. The measurement system and measurement method proposed in the present invention measure the remanent magnetism of ferromagnetic materials by combining a magnetic field sensor with a COMSOL Multiphysics model, and have the advantages of simple operation, real-time display, reliable results, applicability to measuring the remanent magnetism of ferromagnetic materials with irregular shapes or uneven remanent magnetism distribution, and clear and novel principles.

The application discloses a device and a method for rapidly measuring residual magnetism of a tooth surface, and belongs to the technical field of residual magnetism measurement. The device comprises a probe gear module and a signal processing module. The probe gear module comprises a probe gear for driving a meshing rotation of a detected gear, and a Hall sensor array uniformly arranged on each tooth surface of the probe gear. The Hall sensor array is uniformly arranged on each tooth surface of the probe gear. The probe gear is meshed with the detected gear and drives the detected gear to synchronously rotate. During the rotation, each tooth surface of the probe gear is sequentially meshed with a tooth surface of the detected gear. Meanwhile, three-axis Hall sensor array elements located at the meshing point position collect residual magnetism signals of corresponding positions of the detected tooth surface of the detected gear. Point-by-point collection and measurement of residual magnetism of all tooth surfaces of the detected gear are realized. The application does not need a complex scanning mechanism, and can complete rapid measurement of multiple tooth surfaces and multiple points through gear meshing rotation. The application has the advantages of high measurement efficiency, full direction information, easy industrial integration and the like.

Disclosed is an AlNiCo-based hard magnetic particle containing Al, Ni, Co, Cu, Ti, and the balance of Fe. The AlNiCo-based hard magnetic particle contains Co in an amount of 10 to 17 wt %, has a coercive force of 250-450 Oe, and has a residual magnetization / coercive force rate of 0.06 or more. The AlNiCo-based hard magnetic particle according to the present invention can advantageously guarantee magnetic properties suitable for being detected by a magnetic reluctance device due to a low content of Co.

A system for operating at least one magneto-rheological fluid clutch device can change the amount of torque transfer between a driving member and a driven member in the at least one magneto-rheological fluid clutch device in a first mode by actuating at least one coil in the at least one magneto-rheological fluid clutch device. In a second mode, the system can set a desired residual magnetization level in a magnetic component of the at least one magneto-rheological fluid clutch device by actuating at least one coil in the at least one magneto-rheological fluid clutch device, thereby transmitting torque between the driven member and the driving member.

This sintered magnet comprises a first phase having a main phase of Sm-Fe-N-based crystal grains with a Th2Zn17-type structure and a second phase consisting of an alloy containing at least one or more elements selected from Group 2 elements and rare earth elements, the alloy having a temperature range of 180-620°C, wherein a residual magnetization is 10.0 kG or more.

Provided are an R-Fe-B rare earth magnet having excellent squareness and magnetic properties at high temperatures, especially excellent residual magnetization at high temperatures, and a method for manufacturing the same. The present invention discloses a rare earth magnet and a method for manufacturing the same, wherein the rare earth magnet comprises a main phase (10) and a grain boundary phase (20) existing around the main phase (10). The rare earth magnet disclosed in the present invention has an overall composition in terms of molar ratio represented by the formula (R 1 (1－x) La x ) y (Fe (1－z) Co z ) (100－y－w－v) B w M 1 v Indicates that, R 1 is the specified rare earth element, M 1 is a specified element, and 0≤x≤0.1, 12.0≤y≤20.0, 0.1≤z≤0.3, 5.0≤w≤20.0, 0≤v≤2.0. The main phase (10) has R2Fe 14 In the B-type crystal structure, the average grain size of the main phase (10) is less than 1 μm, and in the grain boundary phase (20), the volume ratio of the phase having the RFe2 type crystal structure relative to the grain boundary phase (20) is less than 0.40.

The application discloses a kind of self-adapting gyro wheel probe based on magnetic hysteresis phase change, boiler detection system and method, probe includes flexible wheel shell, granular filling cavity in wheel shell, hard magnetic granular material filled in cavity, excitation coil assembly fixed in gyro wheel axis of rotation and control circuit.Control circuit applies positive pulse current in detection position, so that hard magnetic granular material is magnetized and forms chain-shaped obstruction structure, and gyro wheel is switched from flexible state to rigid state;After positive pulse stops, particle relies on self remanence and intergranular mechanical friction force to keep obstruction state, and applies reverse pulse current to remove obstruction after detection is completed.The application utilizes the remanence effect of hard magnetic particles to realize rigid self-retention after power failure, shortens the coil energization time to the order of pulse width, reduces the heat output, and can work stably in a 300-450℃ boiler environment without active cooling, while avoiding the interference of continuous electromagnetic field on detection signal.

To suppress temperature variations on the substrate while improving adhesion between the substrate and the metal mask. [Solution] The substrate holder comprises a main body having residual magnetization and generating a temperature gradient when current is supplied, and a main surface provided on one side of the temperature gradient in the main body, which attracts the metal mask on the substrate with the magnetic force of the residual magnetization.

The present invention relates to the field of filter element detection technology, and in particular to a silver-based composite filter element detection method and system. The present invention draws a magnetization curve according to an initial magnetic induction intensity value, a plurality of first magnetic induction intensity values, and a second magnetic induction intensity value. By analyzing the magnetization curve, the magnetic response data of the silver-based fiber under different external magnetic field intensities can be quickly obtained. The external magnetic permeability of the silver-based fiber is calculated according to the plurality of second magnetic induction intensity values ​​and the first magnetic induction intensity value. Compared with traditional chemical analysis methods such as atomic absorption spectroscopy, the calculation of the external magnetic permeability can usually be completed more quickly, making the evaluation of the silver content of the silver-based fiber more accurate. The magnetic susceptibility of the silver-based fiber is obtained according to the magnetization curve. The relative amount of the silver content can be indirectly inferred by calculating the magnetic susceptibility. The silver content is calculated according to the magnetic susceptibility, the external magnetic permeability, the residual magnetization intensity, and the plurality of saturation magnetization intensities, so that the silver content can be calculated in more detail and accurately.