378 results about "Magnetic domain" patented technology

The invention provides an intelligent material damage diagnosis method and system based on magnetic characteristic data fusion, and relates to the technical field of nondestructive testing, and the method comprises the following steps: collecting magnetic characteristic data by using a magnetic stress detection robot; performing multi-scale decomposition on the data to construct a magnetic domain evolution characteristic spectrum; inputting the characteristic spectrum into a composite neural network to extract a material damage characteristic matrix; constructing a fusion feature vector by using tensor dimensionality reduction and a multilayer belief transfer network; and realizing damage calculation through temperature field modulation and self-adaptive weight distribution to obtain the damage grade and the residual life. According to the invention, accurate diagnosis of the material damage in the welding seam area of the pressure vessel is realized.

The invention relates to the technical field of control and adjustment, in particular to a steam turbine fault diagnosis system based on multi-parameter fusion monitoring, which is characterized in that a quantum hybrid sensing module is used for establishing a picosecond-level space-time reference through entangled photon pair distribution, and unifying a time sequence label of multi-source heterogeneous data; the hypergraph feature extraction module loads the coefficient to a vibration measurement point vertex attribute channel, dynamically calculates a heat conduction hyperedge weight according to a rotor eccentricity inversion value, aggregates temperature field, vibration spectrum and magnetic domain features in a space-time hypergraph which retains physical topology, outputs a cross-scale aligned fusion feature tensor, and outputs a vibration measurement point vertex attribute channel; generating a diagnosis feature vector to drive a multi-scale twin experience certificate; and the federation decision module triggers a load reduction instruction according to the microscopic crack cloud picture to inhibit thermal stress sudden change, and meanwhile, the feature representation precision is improved through cloud federation optimization hyperedge weight parameters. According to the method, the problem of characterization distortion caused by time sequence asynchronization and scale mismatch of heat and machine coupling data is solved.

The invention discloses a method and a device for controlling magnetizing uniformity of a permanent magnet rotor, relates to the technical field of permanent magnet rotors, and aims to evaluate the risk of uniformity during magnetizing of the permanent magnet rotor in advance and provide effective early warning for magnetizing operation by analyzing temperature change data, shape data and surface defect data and constructing a magnetic field response capability coefficient. Based on monitoring of the internal magnetic domain data and the magnetic data of the permanent magnet rotor in the step S3, the magnetic field stability of the rotor can be dynamically analyzed in combination with the influence of an external magnetic field generated by a magnetizing source on magnetic domain alignment. The comprehensive magnetic performance stability index is generated by comprehensively considering the magnetic field response capability coefficient and the magnetizing state prediction model, and a scientific basis is provided for control and optimization in the subsequent magnetizing process. Intelligent control and optimization are carried out, grade scoring is carried out by setting a risk threshold value R and combining the comprehensive magnetic performance stability index, the magnetizing operation effect can be accurately evaluated, and corresponding control measures are taken under different grades.

According to the displacement modulation and optical assistance-based SERF atom magnetometer magnetic imaging method, an SERF atom magnetometer integrated with a magnetic flux guider is used as a magnetic sensor, and low-frequency magnetic field modulation is introduced to the magnetic sensor by controlling a to-be-tested sample to perform periodic infinitesimal displacement in the sensitive direction of the magnetic sensor; the modulation signal is demodulated by combining a phase-locked amplification technology, and a magnetic response signal subjected to phase-locked demodulation at each spatial position is extracted; constructing a magnetic response matrix through two-dimensional track scanning of micron-order step pitch; an image acquisition module and a reflection optical assembly are introduced for spatial registration so as to monitor the relative position in real time, and the visibility and controllability of the magnetic imaging process are guaranteed; the point-by-point detection of fT-level weak magnetic signals can be realized on the premise that an array structure is not needed; the low-frequency noise interference can be effectively inhibited, the stability and definition of direct-current and low-frequency magnetic field imaging are improved, and the method is suitable for high-resolution space imaging application of weak magnetic sources such as magnetic domain structures, nervous tissue slices and ancient rock samples.

The invention discloses a production method of a high-performance sintered neodymium-iron-boron magnet. The production method comprises the steps of rapid quenching flaking, hydrogen decrepitation mixing, magnetic field forming, multi-stage treatment and composite coating. A nanocrystalline sheet is prepared through a rapid quenching technology, and uniform distribution of a grain boundary phase and rare earth elements is achieved through hydrogen decrepitation and material mixing; forming in a strong magnetic field and applying high pressure to improve the orientation degree; through high-temperature sintering, medium-temperature annealing and low-temperature aging treatment, magnet densification, grain boundary phase reconstruction and a magnetic domain structure are optimized; and finally, the corrosion resistance is improved by adopting a composite coating. The high-performance sintered neodymium-iron-boron magnet produced by the method comprises a main phase alloy, a grain boundary phase additive and a rare earth supplementary phase. Through low-oxygen nanocrystal preparation, grain boundary coordinated regulation and green process integration, compatibility of high performance, low cost and environmental protection is realized, and sustainable development of the rare earth permanent magnet material is promoted.

The invention discloses an AMR magnetic resistance unit, an AMR magnetic resistance module, an angle sensor and a chip wherein the AMR magnetic resistance unit comprises: a first AMR magnetic resistance unit; the first AMR magnetic resistance unit comprises a plurality of first AMR magnetic resistance strips, the plurality of first AMR magnetic resistance strips surround a circle center and are distributed in the radial direction, and each first AMR magnetic resistance strip is of a 60-degree arc-shaped strip-shaped structure. According to the AMR magnetic resistance unit, the AMR magnetic resistance module, the angle sensor and the chip, harmonic waves, especially sixth harmonic waves, can be better eliminated, magnetic domain collective hysteresis and noise are reduced, and the anti-eccentricity capacity is improved.

The invention discloses a low-power-consumption winch sensor based on a tunneling magnetoresistance effect. The low-power-consumption winch sensor comprises a measurement module, a signal conversion unit, a shell, a mandrel, a magnetic rotary disc and a detection assembly. The magnetic turntable and the mandrel are connected and rotate synchronously, the detection assembly comprises a TMR sensing element and N magnets, and the magnetic turntable is provided with mounting blind holes for embedding the magnets; the TMR sensing element is arranged on the shell and comprises a mounting plate and two sensing units, the magnetic domain directions of the two sensing units are perpendicular to the rotation axis, magnetic resistance signals of the two sensing units are converted through the signal conversion unit and input into the measuring module, the horizontal distance between the centers of the two sensing units and the magnet and the rotation axis is R, and the center distance L of the two sensing units is smaller than R * sin (180 degrees / N); the sensor is based on the TMR tunneling magnetoresistance effect, is high in detection sensitivity and low in energy consumption, outputs square wave signals with phase differences, can be used for a measurement module to accurately analyze and calculate the rotating speed and the rotating direction of a winch roller, is simple in overall structure, small in radial size and easy to install, and the installation precision is controlled.

The invention discloses an amorphous wire stress-electromagnetic coupling effect modeling method based on a micro-magnetism theory, and belongs to the technical field of magnetic materials and electromagnetic property regulation and control. According to the method, an amorphous wire micro-magnetic three-dimensional simulation model is constructed, solving is conducted through a finite element method, cross-scale simulation of magnetic domain structure evolution of the amorphous wire under the action of external stress is achieved, the change of effective magnetic conductivity of the amorphous wire under the action of different stress fields is further calculated, the skin effect and the magneto-impedance theory are fused, and the magnetic conductivity of the amorphous wire is calculated. And establishing an amorphous wire electromagnetic impedance spectrum model. According to the method, a quantitative mapping relation among the effective magnetic conductivity, the electromagnetic impedance characteristic and the external stress is established, a magnetic domain structure under the action of different stress fields can be deduced, and key parameters such as the effective magnetic conductivity and the electromagnetic impedance spectrum are output; theoretical guidance is provided for wide application of the amorphous wire in the fields of high-sensitivity stress sensing device design, broadband adjustable electromagnetic wave absorption / shielding, self-sensing composite material structure health monitoring and the like.

The invention relates to a method for dynamically eliminating residual magnetism of an iron core of a converter transformer, and belongs to the field of transformer demagnetization. According to the method, a capacitance energy storage and release device is connected to the two ends of a transformer winding, capacitance energy storage causes RLC oscillation of the transformer, a magnetic field is generated through current caused by the RLC oscillation, and magnetic domains of iron core ferromagnetic materials are rearranged through the changed magnetic field, so that the demagnetization effect on residual magnetism of the transformer is achieved. The method comprises the following steps: drawing a hysteresis loop in the demagnetization process of a transformer by collecting voltage and current data in the demagnetization process, translating an end point of the hysteresis loop to an original point, and judging the residual magnetism direction and size of initial demagnetization according to the area of each quadrant of the hysteresis loop; and then transformer demagnetization is carried out again, the residual magnetism direction and size of the first demagnetization are evaluated according to the hysteresis loop of the second demagnetization, and whether the residual magnetism is smaller than a threshold value is judged. According to the method, the direction and size of residual magnetism in the demagnetization process can be evaluated in real time, the demagnetization energy is dynamically adjusted, and sufficient demagnetization of the converter transformer is ensured.

The invention provides a magnetic code disc film material and a preparation method and application thereof. By introducing the TiN layer, a proper amount of nitrogen atoms can enter lattice gaps of iron, electron cloud distribution of iron atoms is changed, and the magnetic moment of the iron atoms is changed; the magnetic moment of Fe atoms can be influenced by N atoms and crystal structures, an alpha-Fe8N phase is formed in FeCoCr through introduction of N ions, the average magnetic moment of each Fe atom in the alpha-Fe8N phase is 2.4 mu B, alpha-Fe8N is a metastable phase, a sample can finally form stable gamma '-Fe4N through annealing, and the magnetic moment of the stable gamma'-Fe4N is generally about 2.5 mu B-2. 7 mu B and is higher than the magnetic moment 2.2 mu B of the Fe atoms in metal Fe; besides, Ti forms a Ti-Fe weak magnetic phase pinning magnetic domain wall in the FeCoCr thin film, and the coercive force and residual magnetism of the FeCoCr layer can be effectively improved at the same time through the method.

Aa superconducting computing apparatus includes: frequency tunable devices connected to each other and arranged in a shape; a ferromagnetic film disposed adjacent to the frequency tunable devices and having an up magnetic domain or a down magnetic domain; and a control circuit configured to adjust a position of a magnetic domain wall in the ferromagnetic film by applying a current to the ferromagnetic film, wherein the position of the magnetic domain wall controls a resonant frequency of the frequency tunable devices.

The invention relates to the technical field of magnet materials, and discloses a high-temperature-resistant neodymium-iron-boron magnet and a preparation method of the high-temperature-resistant neodymium-iron-boron magnet. The high-temperature-resistant neodymium-iron-boron magnet comprises the following components in parts by weight: 25-30 parts of neodymium, 60-65 parts of iron, 1.0-2.0 parts of boron, 3.0-5.0 parts of lanthanum, 0.5-2.0 parts of zirconium, 0.5-1.0 part of molybdenum and 0.1-0.5 part of nano ceramic particles, and the invention further provides a preparation method of the high-temperature-resistant neodymium-iron-boron magnet. S1, preparing and mixing alloy raw materials; s2, nano ceramic coating treatment is carried out; s3, magnetic field assisted pressing forming; and S4, rapid induction sintering. Through the magnetic field assisted directional pressing process, effective control over grain orientation in the pressing forming stage is achieved, magnetic domain arrangement is more ordered, and the residual magnetism and the energy product are improved. Different from a forming mode with disordered grain directions and poor magnetic anisotropy in an existing common cold pressing process, the technical defect that the utilization rate of magnetic performance is low due to poor orientation is overcome.

The invention discloses an energy-saving control method for a new-energy high-low-voltage direct-current relay. The energy-saving control method comprises the steps of analyzing a mapping relation between a silicon steel sheet stacking angle and a magnetic flux path deviation, calculating magnetic domain wall moving resistance according to magnetic domain boundary stress, determining a magnetic domain overturning speed by combining a magnetic field change rate, and measuring a hysteresis loop width parameter. Adjusting the width and frequency of the excitation current pulse according to the magnetic domain overturning frequency and the hysteresis loop offset and width to obtain an optimized excitation current pulse sequence, and determining the hysteresis loop expansion speed according to the hysteresis loop area change rate; the local high-temperature area temperature is analyzed through the iron core temperature rise rate, the local high-temperature area distribution and the magnetic domain energy dissipation data, if the local high-temperature area temperature exceeds the preset threshold value, the excitation current pulse is adjusted, stable iron core temperature rise control data is obtained, the coercive force change amplitude is determined, the magnetic hysteresis loss and the temperature rise are reduced, the stability of the relay under high-frequency switching is improved, and the reliability of the relay is improved. And the operation efficiency and reliability of the system are greatly improved.

The present invention belongs to the technical field of magnetic materials, and particularly relates to a high-frequency magnetic composite material, a high-frequency magnetic device and a processing method thereof. Among them, the processing method of the high-frequency magnetic composite material includes: mixing magnetic metal particles with a magnetic vortex structure, a solvent and a non-magnetic ceramic phase material and grinding them into a slurry; placing the slurry in a mold and forming it under a low-temperature and low-pressure process; wherein, the conditions of the low-temperature and low-pressure process are that the temperature is lower than 300 °C and the pressure is less than 500 MPa. By using magnetic particles with a magnetic vortex structure, there are no magnetic domain walls in the present invention. At high frequencies, magnetization mainly occurs through magnetization rotation, rather than the traditional domain wall displacement mechanism, which can significantly increase the working frequency of the material to above 100 MHz; in addition, the low-temperature and low-pressure process is adopted to avoid various defects of extreme conditions such as high temperature and high pressure in the traditional process.

The invention provides a permanent magnet magnetizing control method based on magnetic domain dynamics and a magnetizer, and particularly relates to the technical field of permanent magnet magnetizing. Obtaining a three-dimensional model of the permanent magnet to be magnetized, and dividing the three-dimensional model into a plurality of magnetic domain units; obtaining a magnetic moment kinetic equation of each magnetic domain unit; magnetic moment directions of the magnetic domain units are randomly distributed when magnetizing is not carried out, the magnetic moments of the magnetic domains do spin precession under the action of an effective magnetic field, and the magnetic moment directions approach to the direction of the effective magnetic field; the magnetic moment direction of each magnetic domain unit at different moments is subjected to numerical solution, and the change track of the magnetic moment direction of the magnetic domain unit from the initial magnetic moment direction is determined according to the instantaneous magnetic moment direction of the magnetic domain unit at different moments; and determining the consistency degree of the magnetic moment direction of each magnetic domain unit according to the change track, and generating a relation graph of the magnetizing saturation, the pulse magnetic field intensity and the pulse duration. According to the method, the magnetizing precision and efficiency can be improved.

A position measuring device including a first component group and a second component group. The first and second component groups are arranged so as to be movable relative to one another in a measurement direction. The first component group has a domain-wall memory including a domain-wall conductor running in a face. The second component group includes a first magnet and a second magnet. The first and second magnets are arranged end to end in the measurement direction, magnetized such that their magnetization directions run with an orthogonal directional component with respect to the face, and arranged such that they have opposite magnetization directions. The magnets are arranged and configured such that a distance in the measurement direction between the first magnet and the second magnet varies in size along a second direction that is oriented orthogonally to the measurement direction.

The invention provides a method for manufacturing a terbium-dysprosium-iron giant magnetostrictive alloy based on three-dimensional photocuring molding, which comprises the following steps of: firstly, preparing three-dimensional photocuring molding slurry, adopting photosensitive resin as a matrix, and matching with a metal organic chelating agent containing terbium-dysprosium-iron giant magnetostrictive alloy component to enhance the uniform distribution of metal powder so as to ensure the printing precision and the material stability; secondly, the resin and the chelating agent are removed through heat treatment degreasing, the degreasing process is controlled by controlling the heating rate, and structural collapse is avoided; decarburization is carried out in a low-oxygen atmosphere, so that the purity of the alloy is improved, and the structural integrity before sintering is ensured; then reduction treatment is performed to improve the structural stability and purity; and finally, high-temperature sintering is carried out under the assistance of a magnetic field, grain orientation and magnetic domain arrangement are optimized, and the magnetostrictive effect and the force-magnetic energy conversion efficiency are improved. According to the method, three-dimensional light curing forming and magnetic field auxiliary heat treatment are combined, and the risk of structural damage in the printing process of the terbium dysprosium iron giant magnetostrictive alloy is practically and effectively avoided.

The invention relates to the technical field of precoated sand casting, and discloses a precoated sand casting production line based on an intelligent casting island, the precoated sand casting production line comprises a machine body, a sand feeding pipe, a negative pressure sand suction pipe, a distance adjusting piece and a rotatable transmission shaft are respectively mounted in the machine body, and the distance adjusting piece is in transmission connection with two mold frames which are symmetrically arranged and have an adjustable distance; casting systems are arranged on the two mold frames, and each casting system comprises a toothed plate mounted on the machine body, a magnetic field generator mounted on the machine body, a casting frame capable of synchronously moving back and forth and left and right on the mold frames in a reciprocating manner, and a synchronous shaft capable of periodically and alternately rotating forwards and backwards. Technical breakthrough is achieved through the synergistic effect of the magnetic vibration coating and multi-mode vibration, Fe70Ga30 alloy nano-particles of the functional layer generate magnetic domain periodic orientation in an alternating magnetic field, micron-sized multi-axial vibration is excited, the surface of molding sand and a mold interface is deepened, intermolecular acting force is destroyed, deep-layer adhesive sand is stripped in a non-contact mode, and the surface of the mold is stripped in a non-contact mode. The problem that energy penetration of traditional impact type cleaning is insufficient is solved.

Disclosed is an operation method of a neural network element using a Hall voltage. The neural network element has a hole pattern portion, and the hole pattern portion has a cross shape. When a pulse current is applied, horizontal magnetic anisotropy is formed in a ferromagnetic layer by means of spin-orbit torque, and when an external magnetic field in a direction perpendicular to the pulse current is applied, the inversion of magnetization occurs by means of additional torque. The movement of a magnetic domain wall is performed by the inversion of magnetization, spin electrons applied thereby are scattered, and a Hall voltage is generated according to the anomalous Hall effect. The generated Hall voltage increases according to the number of applications of the pulse current or pulse voltage.

To provide a non-heat-resistant magnetic domain refining treatment method capable of predicting a leakage magnetic flux value of a grain-oriented electromagnetic steel sheet after applying magnetic domain refining treatment before applying the magnetic domain refining treatment to the grain-oriented electromagnetic steel sheet.SOLUTION: A non-heat-resistant magnetic domain refining method in which a grain-oriented electrical steel sheet is irradiated with an energy beam to perform non-heat-resistant magnetic domain refining treatment on the grain-oriented electrical steel sheet, the non-heat-resistant magnetic domain refining method comprising: A magnetic flux leakage value prediction step of predicting a magnetic flux leakage value of the grain-oriented electrical steel sheet after being subjected to the magnetic domain refining treatment using a magnetic flux leakage value prediction model learned by machine learning including one or more of surface state parameters of the grain-oriented electrical steel sheet before being subjected to the magnetic domain refining treatment, one or more of environmental condition parameters when being subjected to the magnetic domain refining treatment, and one or more of control parameters of an energy beam when being subjected to the magnetic domain refining treatment, and using the magnetic flux leakage value of the grain-oriented electrical steel sheet after being subjected to the magnetic domain refining treatment as output data.SELECTED DRAWING: Figure 2

The invention provides a cantilever beam probe of an atomic force microscope, a preparation method and an imaging method, and relates to the technical field of semiconductor testing. The method comprises the following steps: fixing a cantilever beam of a first type of atomic force microscope probe with a nanoscale needle tip at the head end on a needle tip of a second type of atomic force microscope probe in a curing connection mode, the cantilever beam probe of the second type of atomic force microscope takes the nanoscale needle tip of the first type of atomic force microscope probe as the needle tip of the cantilever beam probe of the second type of atomic force microscope; wherein the second type of atomic force microscope probe is a micron-sized needle tip, and the micron-sized metal needle tip is formed on a cantilever beam of the quartz tuning fork; one surface, back to the nano-scale needle tip, of the cantilever beam of the first-type atomic force microscope probe is fixedly connected with the micron-scale needle tip, and the fixedly connected position is close to the tail end of the cantilever beam of the first-type atomic force microscope probe; the problem that when a traditional qPlus probe is used for magnetic domain imaging of a magnetic material, enough resolution is difficult to achieve can be solved.

The invention discloses a method for reducing critical current density in SOT driving magnetization overturning, and relates to the technical field of spintronics, and the method comprises the following steps: building a structure model of a magnetic film which is of a double-layer structure, symmetrically arranging two defect areas on the magnetic layer along the x-axis direction, the physical parameter value of the defect area is smaller than that of the magnetic layer; the junction of the magnetic layer and the defect region is a domain wall; the structure model is subjected to micro-magnetic simulation, a magnetic domain and domain wall evolution process is obtained, the critical current density in SOT driving magnetization overturning is determined based on the evolution process, the critical current density is the minimum current density for driving domain wall movement, and the maximum current density is the minimum current density for driving domain wall movement. And the SOT effective field generated by the critical current density is the minimum SOT effective field required for unpinning the domain wall from the defect area. The method can be compatible with the existing micro-nano electronic process and material system.

The invention provides a magnetically soft alloy-based wave-absorbing composite material as well as a preparation method and application thereof, and belongs to the technical field of electromagnetic wave absorbing materials. The wave-absorbing composite material provided by the invention comprises various magnetically soft alloy substrates prepared from elements such as iron, cobalt, nickel and the like and nitrogen-doped carbon coating the surfaces of the magnetically soft alloy substrates. The coercive force of the soft magnetic alloy is relatively low, so that the magnetic domain wall movement and magnetic moment rotation resistance in the material are reduced, the magnetic conductivity is relatively high, and the nitrogen-doped carbon with high dielectricity is combined to construct a magnetic-dielectric structure, so that the impedance matching between the composite material and the space is improved, and the efficient absorption of electromagnetic waves is promoted. The magnetically soft alloy-based wave-absorbing composite material has the characteristics of strong electromagnetic wave absorption performance and wide absorption frequency band, and is simple in preparation technology and easy for large-scale production.

The stretching linkage equipment comprises a traction machine and the tension machine, the traction machine comprises a traction machine frame, a traction winding drum and a guide mechanism, the traction winding drum is installed on the traction machine frame, and the guide mechanism is arranged on the traction machine frame; the tension machine comprises a tension machine frame, an output shaft and a tension winding drum, the tension winding drum is rotationally arranged on the tension machine frame, and the output shaft is fixedly connected to the tension winding drum; a hydraulic resistance braking mechanism is fixedly arranged on the tension rack, and the hydraulic resistance braking mechanism is arranged on the output shaft in a sleeving manner; the tension machine further comprises a gear motor, and the gear motor is arranged on the tension machine frame. The hydraulic resistance braking mechanism comprises a liquid disc, a closed liquid cavity filled with magnetorheological fluid is arranged in the liquid disc, a resistance wheel set is arranged in the liquid cavity, and the resistance wheel set comprises a rotatable resistance blade and a motor; and a magnetic field regulation and control mechanism is arranged outside the liquid disc. The technical problem that hydraulic braking of existing stretching equipment fails is solved by integrating the hydraulic resistance braking mechanism and the magnetic domain regulation and control mechanism through the tensioner.

A superconducting computing apparatus includes: frequency tunable devices connected to each other and arranged in a shape; a ferromagnetic film disposed adjacent to the frequency tunable devices and having an up magnetic domain or a down magnetic domain; and a control circuit configured to adjust a position of a magnetic domain wall in the ferromagnetic film by applying a current to the ferromagnetic film, wherein the position of the magnetic domain wall controls a resonant frequency of the frequency tunable devices.

A spin device is disclosed in which a magnetic domain wall is moved to the center region of a magnetic free layer. The magnetic domain wall is moved and the perpendicular magnetic anisotropy is changed by avoiding a number of defects distributed at the edge or edge region of the magnetic free layer. So, stable operation of the spin device is secured.

The invention discloses a regulation and control method for a magnetic domain structure of an iron-based amorphous alloy strip, which comprises the following steps of: (1) moving a to-be-nicked area of the alloy strip to a workbench through a transmission mechanism, pressing a cutter head on the strip through a six-axis robot arm, and driving a blade to move along the width direction of the strip through the six-axis robot arm, nicks which are arranged at equal intervals and are perpendicular to the length direction of the strip are carved on the free surface of the strip; and (2) the alloy strip subjected to mechanical nicking is subjected to longitudinal magnetic field heat treatment in an inert atmosphere, the magnetic field direction is the length direction of the strip, and water quenching is conducted after treatment. The mechanical nicking device is used for nicking the nicking lines with specific structures at equal intervals on the surface of the amorphous alloy strip, so that various periodic stresses including tensile stress and compressive stress are introduced into the surface of the amorphous alloy strip, and longitudinal magnetic field heat treatment with specific temperature and specific magnetic field intensity is cooperated; and the effects of greatly refining the magnetic domain width and reducing the loss are achieved.

According to the preparation method of the non-oriented silicon steel base, a trace rare earth element Nd is added into molten steel components, nano SiO particles are introduced, continuous casting and rolling processes are improved, a separant formula is optimized, and a mixed separant of AlO and the nano SiO particles is adopted, so that the anti-oxidation, anti-bonding and lubricating properties of the surface of a steel strip are remarkably improved; the surface defects are reduced, the performance of the non-oriented silicon steel is remarkably improved, the microstructure of the non-oriented silicon steel is optimized, and the moving resistance of a magnetic domain wall is effectively reduced, so that the iron loss P17 / 50 is remarkably reduced to 0.7-1.0 W / kg, and the magnetic induction B8 reaches 1.90 T or above and is remarkably higher than the level of a traditional process.

The invention discloses a nonlinear permanent magnet hysteresis loop description method based on magnetic domain energy minimization. The method comprises the following steps: step 1, forming a state equation by using total energy obtained by adding magnetic domain energy of six magnetic domains along easy axis directions of different crystals in permanent magnet crystal grains; 2, the minimum value of magnetic domain energy is solved, and then the optimal direction of each magnetic domain unit magnetization vector in the crystal grains is obtained; and step 3, describing a magnetic domain occurrence probability by using a Boltzmann function, and determining a Preisach model distribution function by using a probability density function so as to obtain a macroscopic hysteresis characteristic. According to the method, micro-magnetic microcosmic characterization and macroscopic magnetic performance are associated from a micromechanism, a magnetization curve of a nonlinear permanent magnet can be accurately established, and the method has an important supporting effect on research work such as electromagnetic multi-physics field simulation and the like.

The invention discloses a method and system for detecting the magnetization direction of an unmagnetized magnet, and belongs to the technical field of magnetic material detection. The method comprises the following steps: applying an external guide magnetic field to a to-be-detected non-magnetized magnet; detecting a signal related to the physical state of the non-magnetized magnet under the action of the guide magnetic field as a response signal; and judging the magnetization direction of the non-magnetized magnet based on the corresponding relation between the response signal and the preset magnetization direction. The corresponding system comprises a guide magnetic field generation unit, a detection unit and a discrimination unit. The modulation effect of magnetocrystalline anisotropy of a non-magnetized magnet on an external magnetic field is utilized, invisible magnetic domain orientation information is converted into externally observable physical field difference, efficient, visual and lossless recognition of the preset magnetization direction is achieved, and the method is suitable for production quality control of magnetic assemblies such as a Halbach magnetic circuit and the like.