34 results about "Residual magnetization" patented technology

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%.

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 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 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.

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.

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 application provides a method for simultaneously improving the remanence and coercivity of a micrometer-scale NdFeB-based permanent thick film. The method is to introduce a combined layer during the growth of the NdFeB-based thick film, and the combined layer is arranged between hard magnetic layers, and the arrangement structure of the combined layer is: isolation layer / soft magnetic layer / isolation layer. The non-magnetic layer in the combined layer acts as an isolation layer to increase the coercivity to a certain extent, and the soft magnetic layer improves the remanence through long-range interaction between the hard magnetic layer and the thick film. The isolation layer is preferably Ta, and the soft magnetic layer is preferably Fe. When the combined layer is inserted into 7 layers, and the thickness of the soft magnetic layer is 80 nm, the remanence of the permanent thick film reaches 1.2 T, and the coercivity is maintained at above 1.5 T. The method provides performance guarantee for the use of the NdFeB-based permanent thick film in MEMS and micro permanent magnet motors.

Provided is a rare earth magnet capable of improving both residual magnetization and coercive force. The rare earth magnet of the present disclosure includes: a main phase; and a grain boundary phase present around the main phase. A total composition in atomic ratio is represented by the formula R1xT(100−x−y−z)(B(1−s)Cs)yMz, R1 is one or more elements selected from the group consisting of Nd, Ce, La, Pr, Gd, Tb, Dy, and Ho, T is one or more elements selected from the group consisting of Fe, Co, and Ni, M is one or more elements selected from the group consisting of Ga, Al, Cu, Au, Ag, Zn, In, and Mn and unavoidable impurity elements, and 12.0≤x≤20.0, 5.00≤y≤20.0, 0≤z≤2.0, and 0.07≤s≤0.17 are satisfied. The main phase has a crystal structure of R2Fe14B type, and R is a rare earth element.

The present application provides a film that can achieve a coercive force Hc of 2.00 kOe or more and a residual magnetization Mrt per unit area of 2.00 memu / cm 2 The in-plane magnetization film has a thickness of 20 nm or more and 80 nm or less, contains 45 at% or more and 80 at% or less of the metal Co, contains 20 at% or more and 55 at% or less of the metal Pt, contains 3 vol% or more and 25 vol% or less of the oxide with respect to the entirety of the in-plane magnetization film, and has an average particle diameter in the in-plane direction of the magnetic crystal grains of 15 nm or more and 30 nm or less.

Provided is a rare earth magnet obtained by subjecting an R—Fe—B-based alloy containing R, wherein R represents a rare earth element containing Nd, Fe, and B to hot plastic processing. The rare earth magnet has a structure of a main phase containing an R2Fe14B compound, an axis of easy magnetization is oriented in a minor axis direction of a crystal grain of the main phase, a thickness dimension in a direction of the axis of easy magnetization is from 0.07 mm to 0.2 mm, and a decrease rate of residual magnetization is 5% or less, wherein the decrease rate (%) of residual magnetization is a rate of decrease in residual magnetization with respect to when residual magnetization of the rare earth magnet having the thickness dimension of 0.5 mm is defined as 100%.

A method for preparing high magnetic performance (Sm x Y 1‑x )Co5 rare earth magnetic particles by chemical method belongs to the field of rare earth magnetic materials. Specifically relates to a kind of new technology using chemical liquid phase synthesis combined with calcium reduction reaction, preparation of high magnetic performance (Sm x Y 1‑x )Co5 ternary alloy magnetic powder. Through chemical coprecipitation combined with hydrothermal reaction, Sm(OH)3 / Y(OH)3 / Co(OH)2@Ca(OH)2 crystalline state mixed precursor is prepared, and a certain amount of metal calcium particles, KCl and CaCl2 diffusion medium are uniformly mixed in argon atmosphere to occur complete calcium reduction reaction, and the magnetic powder is prepared. The incorporation of yttrium element improves the saturation magnetization and remanence of the magnetic powder, but the coercivity of the magnetic powder is slightly reduced. This method provides a new idea for preparing high-performance rare earth magnetic particles.

The invention provides a neodymium-iron-boron material recycling process, and belongs to the field of neodymium-iron-boron waste material recycling. The preparation process comprises the following steps: preparing a mixed leaching solution; carrying out ball-milling roasting, stirring and leaching; preparing a composite extracting agent; adding a composite extraction agent for extraction and separation; and carrying out heating reaction with metal calcium and regenerating the neodymium-iron-boron magnet. Metal elements in the neodymium iron boron material are leached out through the mixed leaching solution, then rare earth ions are extracted out through the composite extraction agent, rare earth elements are separated from non-rare earth elements, all the metal elements are recycled in a precipitation mode, and the recovery rate of the neodymium iron boron material is increased. The neodymium-iron-boron magnet is obtained through regeneration such as calcination, mixing and heating reaction with metal calcium particles, mixing and smelting with ferroboron, crushing and grinding, compression molding and vacuum sintering, the oxygen content is extremely low, and non-ferromagnetic rare earth metal or alloy is not added, so that the residual magnetization intensity and the saturation magnetization intensity of the regenerated neodymium-iron-boron magnet can be effectively improved; and the effect of improving the practicability of the regenerated neodymium-iron-boron magnet is achieved.

The invention discloses a zinc-doped manganese cobaltate-based magnetic refrigeration material and a preparation method and an isothermal residual magnetization measurement method thereof, the chemical general formula of the magnetic refrigeration material is as follows: x is more than or equal to 0.1 and less than or equal to 0.4, and when the magnetic field is 5T, the RCP value of the material is up to 82.13 J / kg. The preparation method comprises the following steps: oscillating, ball-milling, drying and grinding the raw materials prepared according to the stoichiometric ratio; pre-sintering the product twice, naturally cooling and grinding; mixing and grinding polyvinyl alcohol and the pre-sintered product, and tabletting and molding; calcining to remove polyvinyl alcohol; and sintering for 10-30 hours at the temperature of 980-1150 DEG C to obtain the zinc-doped manganese cobaltate-based magnetic refrigeration material.

Provided are a magnetic recording medium including a non-magnetic support and a magnetic layer containing a ferromagnetic powder, a magnetic tape cartridge including the magnetic recording medium, and a magnetic recording reproduction device. The magnetic field 0.3 of the magnetic recording medium is between 4.0 kOe and 8.0 kOe (both inclusive). The magnetic recording medium is a magnetic tape or a magnetic disk. The magnetic field 0.3 is a value on the high magnetic field side of the two values on the horizontal axis at which the value on the vertical axis is 0.3, in a graph in which the residual magnetization obtained by measurement with a vibrating sample magnetometer as the vertical axis value is plotted against the value of the applied magnetic field in the longitudinal direction of the magnetic tape or in the radial direction of the magnetic disk on the horizontal axis, and the differential curve obtained by differentiating these plots is normalized to a maximum value of 1 on the vertical axis.

To provide a method for manufacturing a magnetoplumbite-type hexagonal ferrite magnetic powder capable of making a ferrite-based bond magnet exhibit excellent residual magnetization.SOLUTION: A first embodiment of the invention is a method of producing a magnetoplumbite-type hexagonal ferrite magnetic powder, including a firing step of firing a mixture containing a raw material powder and a metal chloride to obtain a fired product, and a pulverizing step of pulverizing the fired product to obtain a powder, in which a molar ratio of an amount of Cl contained in the metal chloride to an amount of Fe contained in the raw material powder is 0.002 or more and 0.020 or less.SELECTED DRAWING: None

This invention provides a technology to improve the coercivity and remanent magnetization of Sm-Fe-N based magnetic powders. [Solution] The Sm-Fe-N magnetic powder has a particle size distribution D50 of 2 μm or more and 3 μm or less, and the full width at half maximum of the diffraction intensity peak in the (220) plane obtained from X-ray diffraction of the Sm-Fe-N magnetic powder is 0.1 degrees or more and 0.2 degrees or less.

We will improve the magnetic circuit that incorporates multiple types of magnets. [Solution] The device includes a first magnet 102 having a first remanent magnetization value and a first coercivity value, the first magnet having a first cross-sectional area substantially perpendicular to the magnetization direction of the first magnet, and a second magnet 104 arranged in series with the first magnet, the second magnet having a second remanent magnetization value and a second coercivity value smaller than the first coercivity value, and having a second cross-sectional area substantially perpendicular to the magnetization direction of the second magnet. The ratio of the first cross-sectional area to the second cross-sectional area is equal to or greater than the ratio of the second remanent magnetization value to the first remanent magnetization value.

The invention relates to a sintered magnet, a method for producing a powder for a sintered magnet, and a method for producing a sintered magnet. [Problem] To provide a technique for improving residual magnetization in an Sm-Fe-N sintered magnet. [Solution] Provided is a sintered magnet which contains a first phase that is mainly composed of Sm-Fe-N-based crystal grains having a Th2Zn17-type structure. The density of the sintered magnet is 6.5 g / cm3 or more, and the full width at half maximum of the peak of the diffraction intensity of the (220) plane obtained by X-ray diffraction is 0.2-0.3 degrees (inclusive).

The invention relates to a rare earth magnet and a manufacturing method thereof. Provided is a rare earth magnet capable of improving both remanent magnetization and coercive force. A rare earth magnet according to the present invention is characterized by comprising a main phase and a grain boundary phase present around the main phase, the overall composition of the rare earth magnet in terms of atomic ratio being represented by the formula R1xT (100-x-y-z) (B (1-s) Cs) yMz (wherein R1 is one or more elements selected from Nd, Ce, La, Pr, Gd, Tb, Dy, and Ho, T is one or more elements selected from Fe, Co, and Ni, y is one or more elements selected from Fe, Co, and Ni, y is one or more elements selected from Fe, Co, and Ni, y is one or more elements selected from Fe, Co, and Ni, and y is one or more elements selected from Fe, Co, and Ni, and y is one or more elements selected from Fe, Co, and Ni. M is one or more elements selected from Ga, Al, Cu, Au, Ag, Zn, In, and Mn, and unavoidable impurity elements, and 12.0 < = x < = 20.0, 5.00 < = y < = 20.0, 0 < = z < = 2.0, and 0.07 < = s < = 0.17. ), and the main phase has an R2Fe14B type (wherein R is a rare earth element. ).

[Object] To provide a thermoelectric body that can be deposited on any substrate, which is not limited to a single crystal bulk material or an epitaxially grown thin film, and is capable of exhibiting high coercive force and residual magnetization with respect to in-plane magnetization.[Solving Means] A thermoelectric body that is a magnetic film for use in a thermoelectric generation element utilizing an anomalous Nernst effect, characterized by having an easy axis of magnetization in an in-plane direction and an amorphous structure. Favorably, the thermoelectric body is characterized in that SmpCo100-p (0<p≤50) or Smp(FeqCo100-q)100-p (0<p≤50, 0≤q≤100) is included.

The invention discloses a method and device for extracting residual magnetization information of rock, and belongs to the field of geophysics. Compared with the prior art, according to the method for extracting the residual magnetization information of the rock, the difference between the vector magnetic anomaly and the scalar magnetic anomaly containing the residual magnetization information is analyzed on the basis of the aeromagnetic three-component data collected through measurement, so that the residual magnetization information of the rock is represented, and the method is more accurate; and a more reliable basis is provided for geological interpretation of magnetic method data.

The application relates to a magnetic shielding dynamic degaussing simulation analysis method, an optimization method and a medium, wherein the simulation analysis method comprises the following steps: constructing a three-dimensional finite element model of a magnetic shielding structure, an internal air domain and an external infinite air domain; applying a magnetic insulation boundary condition to the outer surface of the external infinite air domain, and applying a constant geomagnetic bias field as a global static background field; applying a periodic alternating and exponentially decaying degaussing excitation to the magnetic shielding structure; under the degaussing excitation, based on a dynamic magnetization model, a multi-cycle step iteration and transient separation solving strategy is adopted to solve the dynamic evolution process of the magnetization intensity of the magnetic shielding material; after the degaussing excitation ends, the residual magnetization intensity distribution of the magnetic shielding material is determined, and the residual magnetic field distribution of the internal air domain is obtained based on the residual magnetization intensity distribution, so that the prediction accuracy and efficiency of the residual magnetic field are improved.

The present invention provides a method for manufacturing a ring magnet that can increase the magnetic force of the ring magnet, as well as a rotor, motor, blower, and refrigeration apparatus. [Solution] The method for manufacturing a ring magnet includes an installation step of installing a first magnet 51 in a first region 72 of a cavity 71 of a mold body 70, and a molding step of forming a second magnet by injecting a bonded magnet material containing magnetically anisotropic magnetic powder into a second region 73 of the cavity 71. A magnetic field generating unit 80 that generates a magnetic field in the cavity 71 has magnetic poles arranged in the circumferential direction A2 of the cavity 71. The second region 73 is a region aligned with the first region 72 in the circumferential direction A2. In the installation step, the first magnet 51 is installed so that the direction of its residual magnetization is aligned with the direction of the magnetic flux of the magnetic field generating unit 80. The molding step is performed after the installation step.

The application provides a high-precision inversion method for the crustal interior based on aeromagnetic data, which comprises the following steps: preprocessing the aeromagnetic data of a target area, eliminating noise and interference, and extracting regional magnetic anomaly information related to the deep crustal interior; constructing a residual magnetization strength model based on a depth attenuation function, and obtaining the residual magnetization strength of each grid point in the target area according to the target area and the residual magnetization strength model; establishing a nonlinear decay model of the residual magnetization strength with depth based on the residual magnetization strength model, and obtaining the magnetic anomaly strength generated on the ground by each depth layer in the target area by using the nonlinear decay model; and inputting the regional magnetic anomaly information, residual magnetization probability parameters, geological constraints and magnetic anomaly strength into a crustal interior inversion model to obtain the depth prediction value of the target area. The application considers the influence of residual magnetization on the magnetization direction, and improves the inversion precision of the crustal interior.

The invention provides a method for enhancing the magnetic performance of an anisotropic NdFeB thick film through soft and hard magnetic compounding and grain boundary diffusion, and belongs to the technical field of permanent magnet material preparation. According to the method, a plurality of functional units are alternately deposited on a substrate, each unit sequentially comprises a diffusion layer, a hard magnetic layer and a soft magnetic combination layer, and the soft magnetic combination layer is of an isolation layer / soft magnetic layer / isolation layer structure; and performing heat treatment on the multi-layer structure, so that diffusion layer elements are migrated to a hard magnetic layer grain boundary. The permanent magnet thick film is formed by periodically stacking a plurality of such functional units. The hard magnetic layer is made of an NdFeB-based rare earth permanent magnet material; the isolating layer is one or more of Ta, Mo, W and Ti; the soft magnetic layer is one or more of Fe, Co and Ni and alloy of the Fe, the Co and the Ni; the diffusion layer is selected from one or more of Dy, Tb, Gd, Ho, Nd, Cu, Al and Ga. According to the anisotropic NdFeB thick film, the synergistic effect of soft and hard magnetic compounding and grain boundary diffusion is achieved through the structural design, and the residual magnetization and coercive force of the anisotropic NdFeB thick film are effectively and synergistically improved.

The invention discloses a magnetic shielding simulation method and system based on magnetic equivalent current and electronic equipment, and relates to the technical field of magnetic shielding. The method comprises the following steps: establishing a first finite element model of a shielding layer material with non-linear magnetic characteristics of a hysteresis-free magnetization curve; acquiring a parameter of the shielding layer material in a residual magnetization state after demagnetization, wherein the parameter is a difference value between the residual magnetic flux density and the non-hysteresis magnetic flux density in the same environment magnetic field; calculating a magnetic equivalent current value representing the residual magnetization state based on the difference parameter; the magnetic equivalent current value serves as an excitation source to be loaded to a geometric position, corresponding to the actual degaussing coil, in the first finite element model, and a second finite element model is obtained; and solving the second finite element model to obtain the internal residual magnetic field distribution of the magnetic shielding device. The residual magnetism of the material is accurately represented through the magnetic equivalent current, efficient and accurate prediction of the residual magnetic field of the magnetic shielding device is achieved, and the contradiction between traditional simulation accuracy and efficiency is solved.