524 results about "Remanence" patented technology

The invention discloses an efficient and high-precision compensation system and method of an intelligent mutual inductor, and particularly relates to the technical field of mutual inductors. The method comprises the following steps: acquiring magnetic flux density and magnetic field intensity data of a mutual inductor under different current and voltage change rates, generating a hysteresis loop diagram, extracting hysteresis loop width, residual magnetism and coercive force characteristics, and establishing a hysteresis effect error model; the harmonic distortion is identified in combination with spectrum analysis, the harmonic distortion degree in a high-frequency environment is predicted, the hysteresis of the hysteresis effect and the harmonic distortion are comprehensively analyzed, and the accuracy of a compensation algorithm for processing nonlinear errors is evaluated; and finally, the compensation signals are divided into high-accuracy signals and low-accuracy signals, the high-accuracy signals are directly output, and the low-accuracy signals are output after error correction, so that the problem that a conventional compensation algorithm cannot correct non-linear errors is effectively solved, and the measurement precision of the mutual inductor in an extreme environment and the operation stability of a system are improved.

The invention discloses a neodymium-iron-boron magnet, which comprises main phase crystal grains, a thin layer crystal boundary phase and a triangular region crystal boundary phase, and is characterized in that the neodymium-iron-boron magnet comprises 28 to 33 weight percent of R, 0.84 to 0.94 weight percent of B, 0.05 to 1 weight percent of Co, 0.05 to 0.55 weight percent of Cu, 0.3 to 0.6 weight percent of Ga, 0 to 0.55 weight percent of M2, 0.1 to 0.6 weight percent of M3, 66 to 70 weight percent of Fe and the balance of Fe, wherein R is a rare earth element and at least comprises PrNd; the triangular region grain boundary phase comprises an R6T13M1 phase, the element M in the R6T13M1 phase is selected from any two or more elements of Al, Cu, Ga, Ti, Sn and / or Zr, and the element T comprises Fe and / or Co; the sum of the areas of the R6T13M1 phases in the microscopic structure cross section of the neodymium-iron-boron magnet accounts for 5.2%-8.4% of the area of the microscopic structure cross section. The rare earth permanent magnet with high residual magnetism, high coercive force and good squareness consistency is obtained under the condition that no heavy rare earth is added or a small amount of heavy rare earth is added.

The invention discloses an external magnetic field active-disturbance-rejection control method and system based on Kalman filtering, and the method comprises the steps: firstly, building an external coil control system to compensate a residual magnetic field in a magnetic shielding cabin measured by a three-axis fluxgate sensor, and enabling the residual magnetic field to be reduced to a normal working range of Quspin; then starting a Quspin sensor, performing data filtering and fusion on the fluxgate sensor and the Quspin sensor through a Kalman filter, and inputting a fusion value and a control quantity into an extended state observer to realize online estimation of a state and total disturbance; and performing feedback control of related linear state errors on the total disturbance estimator so as to compensate a residual magnetic field and magnetic field disturbance in the magnetic shielding cabin. The magnetic field interference resistance of the active magnetic compensation device can be enhanced, the control precision of an external coil control system on the magnetic field in the cabin is effectively improved, and the cost of the magnetic shielding cabin is reduced.

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 relates to the technical field of magnetic materials, in particular to a grain boundary diffusion method of a neodymium-iron-boron rare earth permanent magnet material, which comprises the following steps: preparing a sintered neodymium-iron-boron diffusion matrix, a diffusion source being turbid liquid slurry consisting of a mixture of rare earth fluoride and rare earth oxide and a proper amount of organic solvent; the method comprises the following steps: processing a diffusion substrate into a required size, carrying out grain boundary diffusion treatment after oil removal and acid pickling treatment, coating the surface of the diffusion substrate with a diffusion source, drying the coated magnet, carrying out primary diffusion treatment, and carrying out secondary low-temperature tempering treatment. The diffusion method provided by the invention is simple in process, can effectively improve the coercive force of the neodymium-iron-boron magnet, especially the coercive force of a Ce-containing magnet, and is embodied in the following aspects: improving the anisotropic field of the surface of a crystal grain, improving the microstructure of a crystal boundary, effectively increasing the diffusion depth, obviously improving the coercive force of the magnet, and improving the coercive force of the neodymium-iron-boron magnet. And the original residual magnetism and the maximum magnetic energy product of the magnet are not obviously reduced.

The invention discloses a neodymium-iron-boron magnet with double main phases and light rare earth diffusion based on asymmetric cerium distribution and a preparation method, and relates to the technical field of neodymium-iron-boron magnets. The method comprises the steps that a diffusion matrix is prepared through a double-main-phase technology, in the double-main-phase technology, the components of a main-phase alloy and an auxiliary-phase alloy are RaCebFe100-a-b-c-dMcBd, R is PrNd alloy or Nd metal, M is at least one of Cu, Al, Zr, Co and Ga, the content of Ce in the main-phase alloy is larger than that of Ce in the auxiliary-phase alloy, then the upper surface and the lower surface of the diffusion matrix are coated with a diffusion source solution, and the diffusion matrix is obtained through heat treatment. Carrying out heat treatment and aging treatment to obtain a neodymium-iron-boron magnet; the diffusion source solution is formed by mixing a diffusion source and a solvent, and the diffusion source is (PrmNdn) aAlbCucZrdCoeMgf. The neodymium-iron-boron magnet obtained through the method has high residual magnetism and high coercive force at the same time, the diffusion efficiency of the diffusion source is high, and the rare earth utilization rate is increased.

The invention discloses a reweighted inversion method and system for a magnetic anomaly modulus under a residual magnetism condition and a storage medium, and belongs to the technical field of magnetic exploration, and the method comprises the following steps: converting the magnetic anomaly modulus to obtain the magnetic anomaly modulus; carrying out nonlinear forward modeling on the magnetic anomaly modulus; and linearizing a forward modeling formula of the magnetic anomaly modulus, constructing a reweighted minimum model objective function, solving the reweighted minimum model objective function, finally obtaining the magnetization intensity of an inversion space, and delineating a target geologic body. According to the scheme, the nonlinear forward modeling formula of the magnetic anomaly modulus is subjected to linear representation, and the sensitivity matrix serving as depth weighting is further updated by utilizing the magnetic anomaly modulus kernel function matrix updated along with iteration, so that the reweighting minimum model objective function is constructed, the precision of magnetic anomaly modulus inversion under the residual magnetism condition is improved, and the accuracy of the magnetic anomaly modulus inversion under the residual magnetism condition is improved. And a more reliable inversion result is provided for more accurate depiction of a deep magnetic structure, mineral resource exploration and the like.

The invention discloses a neodymium iron boron magnet with a protective film and a manufacturing method thereof, and the manufacturing method specifically comprises the following steps: S1, pretreating a plurality of raw materials to ensure the purity and cleanliness of the raw materials; s2, the pretreated materials are mixed in proportion and smelted to prepare uniform neodymium-iron-boron alloy; s3, the smelted alloy is crushed, and particle powder meeting the requirement is prepared through jet mill equipment; s4, the powder is put into a mold, forming orientation is conducted through a magnetic field press, and the maximum residual magnetism is obtained; s5, performing high-temperature sintering on the molded magnet to improve the density and the magnetic performance of the molded magnet; s6, the sintered magnet is machined, and the needed size and shape are obtained; s7, carrying out pretreatment on the surface of the magnet, and carrying out aftertreatment after chemical nickel plating to ensure the quality of a plating layer; according to the method, the surface of the neodymium-iron-boron magnet is coated with a high-phosphorus chemical nickel layer in a plating mode, the magnet can be effectively prevented from being corroded by the external environment, and the service life of the magnet is prolonged.

The invention provides a cement-based material residual magnetism intensity detection device, a detection method and an evaluation method. The cement-based material residual magnetism intensity detection device comprises a magnetic shielding cylinder, a fluxgate magnetometer and a test tool, the magnetic shielding cylinder is used for shielding a magnetic field to ensure stable test environment magnetic field; the fluxgate magnetometer comprises a fluxgate probe and a fluxgate digital display meter, the fluxgate probe is used for measuring a vector value of space magnetic induction intensity at a position corresponding to the fluxgate probe, and the fluxgate digital display meter is used for displaying a residual magnetism intensity measured value measured by the fluxgate probe; the test tool is arranged in the magnetic shielding cylinder and is used for placing a sample to be tested and fixing a fluxgate probe; according to the invention, a fluxgate magnetometer and a magnetic shielding cylinder are adopted to detect the residual magnetism intensity of the cement-based material, a standardized detection process and a test method are provided for solid components, a liquid mixture and a molded test block, and quantitative characterization of the distribution rule of the residual magnetism intensity of the cement-based material is realized through fewer detection points.

Disclosed are a neodymium-iron-boron magnet material, a preparation method, use thereof and a motor. The neodymium-iron-boron magnet material has an amorphous RE-rich phase located in a grain boundary phase. The amorphous RE-rich phase, containing elements TM, RE, Cu and Ga at an atom ratio of TM:RE:Cu:Ga=(15-30):(40-60):(10-25):(10-30), accounts for 3-8% by volume of the grain boundary phase. TM is Fe and Co. RE is a rare earth element. The neodymium-iron-boron magnet material increases the coercivity using none or a small amount of heavy rare earth elements, while maintaining high remanence and magnetic energy.

The invention relates to the technical field of neodymium-iron-boron magnets, in particular to a neodymium-iron-boron rare earth magnet and a preparation method thereof.The neodymium-iron-boron rare earth magnet is a sintered neodymium-iron-boron permanent magnet and comprises a main phase, a two-particle grain boundary phase and a triangular area grain boundary phase; the main phase comprises an R2T14B phase, R refers to at least one of Nd and Pr, T refers to Fe, and Co at least contains Fe; the two-particle grain boundary phase comprises a grain boundary copper-rich phase, and / or a needle-shaped ZrBx phase with the width of 10-50 nm, and / or a needle-shaped TiBx phase with the width of 10-50 nm; the triangular region grain boundary phase comprises an FCC type NdOx phase, an RCu phase, an RGa phase, an R-rich phase, a 6: 14 phase and / or a needle-shaped ZrBx phase with the width of 10-50 nm and / or a needle-shaped TiBx phase with the width of 10-50 nm, the neodymium-iron-boron rare earth magnet does not contain heavy rare earth and is good in uniformity, and the coercive force and residual magnetism can be regulated and controlled through the design of the grain boundary phase.

The invention belongs to the technical field of magnetic materials and sensing, and particularly discloses a magnetic code disc material, an angular displacement magnetic sensor, a high-speed motorized spindle of a numerical control machine tool and a preparation method.The magnetic code disc material comprises a metal substrate, a Ta buffer layer, a FeCoCr-clamped TaN low-dimensional magnetic film and a Ta protective layer, the invention also discloses an angular displacement magnetic sensor made of the magnetic code disc material, the angular displacement magnetic sensor has 512 phase-AB magnetizing magnetic poles, and the distance between the phase-AB magnetizing magnetic poles is 0.4 mm; and one Z-phase magnetizing magnetic pole is arranged, the width is 0.4 mm, and the Z phase is not diffused. The magnetic code disc material disclosed by the invention has more excellent magnetic domain size, excellent coercive force and residual magnetism performance, so that more excellent magnetic pole density can be provided when the magnetic code disc material is applied to an angular displacement magnetic sensor, the signal density is higher, and the magnetic code disc material can be applied to the angular displacement magnetic sensor through the AB-phase and Z-phase matching structure of the magnetic sensor. Therefore, when the angular displacement magnetic sensor is applied to a high-speed motorized spindle of a numerical control machine tool, the precision of the numerical control machine tool can be improved.

The invention provides a method for preparing a high-coercivity sintered neodymium-iron-boron magnet, and belongs to the technical field of rare earth permanent magnet material preparation, and the method comprises the following steps: 1, taking the sintered neodymium-iron-boron magnet as a base material, and removing an oxide layer through alkali washing deoiling, ultrasonic water washing and acid pickling cleaning; 2, taking the Pr-Dy-Cu-Ga quaternary alloy as a diffusion source, and cutting the Pr-Dy-Cu-Ga quaternary alloy into slices; 3, attaching the thin sheet to the surface of a base material for diffusion heat treatment; fourthly, low-temperature tempering is conducted; 5, testing a room temperature demagnetization curve of the sample; light rare earth Pr replaces a part of heavy rare earth Dy and is matched with Cu and Ga elements in a certain proportion to be smelted to obtain quaternary alloy, the quaternary alloy with low heavy rare earth serves as a diffusion source, the microscopic characteristics of the magnet are improved, grain boundary phase distribution is optimized, and under the condition that residual magnetism and the maximum magnetic energy product are slightly reduced, the coercive force of the sintered neodymium-iron-boron magnet is improved; and terbium and dysprosium are not used, so that the use amount of heavy rare earth elements and the production cost are reduced.

The present invention discloses a demagnetization method based on a weak magnetic environment. A three-axis geomagnetic compensation coil is built outside a passive shielding device. Current is injected into the coil to generate a reverse magnetic field to offset the geomagnetism, thereby providing a weak magnetic environment for the shielding device. Based on the weak magnetic environment, a demagnetization power supply control system and a demagnetization coil are used to demagnetize the passive shielding layer of the magnetic shielding device, thereby further improving the demagnetization performance. This method can not only reduce the cost of using high-performance shielding materials when the magnetic shielding device adopts multi-layer shielding, but also effectively reduce the residual magnetism inside the shielding space, thereby constructing an extremely weak magnetic environment.

The invention discloses a ferromagnetic cavity physical and magnetic coupling modeling method, and relates to the technical field of electromagnetic property analysis, the method adopts a COMSOL Multiphysics finite element simulation technology, and combines hysteresis loop measurement of a ferromagnetic material, a Jiles-Atherton parameter recognition algorithm, a tensile test, residual magnetism measurement and a force and magnetic coupling test, so that the ferromagnetic cavity physical and magnetic coupling modeling method is realized. According to the method, the magnetization behaviors of the ferromagnetic cavity under the action of different stresses and magnetic fields are accurately simulated, the high-precision force-magnetic coupling simulation model is established by automatically identifying five Jiles-Atherton parameters of the ferromagnetic material and combining mechanics and residual magnetism data, space magnetic field distribution under the specified working condition is rapidly calculated, and the method has the advantages of being high in modeling efficiency and high in calculation precision.

The invention belongs to the technical field of neodymium iron boron rare earth permanent magnets, and relates to a cerium-containing neodymium iron boron magnet with high coercivity and high stability and a preparation method thereof. According to the preparation method, the cerium-containing copper auxiliary alloy and the neodymium iron boron magnetic powder are ingeniously combined, the whole preparation process is optimized, and remarkable technical progress and economic benefits are achieved. Firstly, in the aspect of magnetic performance, Ce in a specific proportion is added into the cerium-containing copper auxiliary alloy, the cerium-containing copper auxiliary alloy is used, the coercive force of a magnet is effectively improved, high residual magnetism is kept to a certain degree, and introduction of Cu is beneficial to refining of grains and improvement of a grain boundary phase structure; therefore, the reverse magnetization resistance in the magnet is enhanced, and the magnet can maintain stable performance in a wider temperature range.

The present invention relates to the technical field of powder metallurgy, and in particular to a sintered NdFeB and a preparation method thereof, wherein the heat treatment temperature and time are adjusted to promote the RE6Fe 13 The M phase is generated or disappears, thereby increasing or decreasing the remanence and coercivity of the magnet; specifically, by composition design or adding RE6Fe to the grain boundary 13 The M phase alloy composition is then adjusted to 420‑700°C heat treatment temperature to promote RE6Fe 13 The M phase is formed or disappears. This method can regulate the changes in remanence and coercivity within a certain range to improve the redundancy of the formulation process, and at the same time can better adapt to the different performance requirements of customers, with excellent economic benefits.

The invention discloses a fault signal dual-mode output method of a magnetic latching relay, particularly relates to the technical field of relay control, and is used for solving the problem of low mode switching efficiency caused by an existing physical jumper mechanism. The current mechanical state of the relay is detected by receiving a remote dual-mode switching instruction; applying a driving voltage sequence corresponding to the target mode according to the state; based on the iron core residual magnetism intensity and the dynamic margin of a target mode nominal value, judging and generating a driving enabling or degaussing trigger signal; when a driving enable signal is responded, the lag time difference between the voltage rising edge and the magnetic flux jump starting point is captured in real time, and the eddy current loss characterization quantity is generated by combining the product integration of the current differential and the temperature rise; adjusting the rising slope and the duty ratio of the driving voltage sequence according to the lag time difference and the over-limit condition of the eddy-current loss characterization quantity; and finally, the matching between an execution result and a target mode identifier is verified by controlling a coil current response waveform, and the continuous holding mode and the instantaneous pulse mode are remotely and reliably switched.

The invention discloses a method and a system for detecting shielding performance of a shipborne paleomagnetic laboratory, and relates to the technical field of paleomagnetic laboratory detection. According to the invention, a plurality of measurement points are arranged in the shipborne paleomagnetic laboratory, so that the magnetic induction intensity data in the shipborne paleomagnetic laboratory can be accurately and fully measured, and the accuracy of subsequent calculation of the internal average residual magnetism and the shielding coefficient of the shipborne paleomagnetic laboratory is improved; the detection accuracy of the shielding performance of the shipborne paleomagnetic laboratory is further improved; the ship navigation state of the ship is continuously adjusted, the operation environment of the shipborne paleomagnetic laboratory is fully considered, and the situation that the shielding performance of the shipborne paleomagnetic laboratory is detected inaccurately due to the navigation uncertainty of the ship and the complex magnetic environment of the ship navigating in the ocean is avoided in a multi-ship navigation state and multi-measurement-point mode. The accuracy of the internal average residual magnetism and the shielding coefficient is improved through the dynamic characteristics of the ship, and the detection accuracy of the shielding performance of the shipborne paleomagnetic laboratory is ensured.

The invention discloses a method for simultaneously optimizing the squareness and the remanence temperature coefficient of a 2: 17 type samarium-cobalt sintered magnet, and belongs to the technical field of rare earth permanent magnet material preparation. A component Sm < 1-x > RE < x > (CobalFeaCubZrc) z is designed, RE is one or more of Dy, Er, Gd, Tm and other heavy rare earth elements, and a, b, c and x meet the following relations: 0 < = x < = 0.6, 0.1 < = a < = 0.2, 0.06 < = b < = 0.12, 0.02 < = c < = 0.03, and 6.9 < = z < = 7.9. On the basis of a conventional smelting and ingot casting-isothermal annealing-powder preparation-oriented profiling-sintering-solid solution-aging process, an isothermal annealing process is added after smelting and ingot casting: the temperature is raised to 1190-1210 DEG C in a tubular furnace, isothermal annealing is performed for 5-20 hours, heavy rare earth elements are eliminated, and the influence of the stability of a 2: 17H phase on the component uniformity and magnetic performance of a magnet is improved; and substitution sites of heavy rare earth can be increased, and the residual magnetism temperature coefficient is optimized.

The present invention provides a flywheel energy storage flux adjustable induction motor and its magnetic adjustment method, wherein the motor comprises two permanent magnets with different coercive forces and a DC magnetic adjustment winding. A square wave pulse is input into the DC magnetic adjustment winding to generate a magnetic adjustment magnetic field, so that the residual magnetism of the low-coercive force permanent magnet changes in magnitude or direction, thereby realizing rapid adjustment of the motor air gap flux. When the motor is working, the DC magnetic adjustment winding is disconnected, and the residual magnetic flux generated by the high-coercive force permanent magnet and the low-coercive force permanent magnet enters the air gap in parallel to provide excitation flux for the motor; when the motor is on standby, a negative square wave pulse is input into the DC magnetic adjustment winding to generate a magnetic adjustment magnetic field that can reversely saturate magnetize the low-coercive force permanent magnet, so that the low-coercive force permanent magnet is reversely magnetized, and the residual magnetic flux of the high-coercive force and low-coercive force permanent magnets is equal in magnitude and opposite in direction, so that the air gap flux is reduced to 0, thereby eliminating standby iron loss. In addition, the DC magnetic adjustment winding can also be used as a backup excitation source to prevent the risk of permanent magnet demagnetization.

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 discloses a zero magnetic shielding device and a use method thereof, and the device comprises a magnetic shielding cylinder which is composed of a shielding cylinder body and a shielding cover detachably connected with the shielding cylinder body. And the non-magnetic multifunctional test frame is arranged in the magnetic shielding cylinder and consists of an arc-shaped seat, a lifting mechanism, a test bedplate, a track, a storage rack, a Helmholtz coil and a folding nylon magnetic sensing assembly. When the magnetic flux and residual magnetism switching test is carried out on the object to be tested in the magnetic shielding cylinder, the non-magnetic multifunctional test frame does not need to be replaced, the efficiency of the magnetic flux and residual magnetism switching test on the object to be tested in the magnetic shielding cylinder is improved, and the advantage of convenient switching test is achieved. And the method has the advantages of high measurement precision and wide application range.

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.

The invention discloses a rare earth reduction regulation and recovery method for high-cerium-content sintered neodymium-iron-boron waste, and belongs to the field of neodymium-iron-boron waste recovery. Performing hydrogen explosion on the magnet subjected to surface treatment to obtain hydrogen explosion coarse powder; carrying out jet milling on the hydrogen explosion powder to obtain jet milled powder; fully mixing the airflow fine powder with a small amount of light rare earth element supplements, and carrying out orientation compression, sintering and tempering to obtain a single-phase sintered regenerated magnet; and carrying out grain boundary diffusion on the obtained regenerated sintered magnet by using a diffusion source containing a small amount of medium rare earth Nd, Pr or alloy thereof to obtain the high-performance regenerated magnet. According to the method, a small amount of light rare earth is added to inhibit the second phase, and then high-performance regeneration of the magnet waste is achieved through grain boundary diffusion of reduced rare earth elements such as Nd and Pr and alloy. The regenerated magnet prepared by the method is lower in total rare earth content, higher in light rare earth content, and better in residual magnetism, coercive force and comprehensive magnetic energy product.

The invention relates to the technical field of magnetic shielding, and discloses a self-adaptive active adjustment type magnetic shielding device demagnetization circuit and device, and a control acquisition system, which are used for comparing a residual magnetism state with a preset expected value and generating a control instruction; the energy output identification system is used for outputting an alternating current degaussing signal according to the control instruction to perform degaussing, outputting an excitation pulse signal to perform residual magnetism detection, identifying a zero crossing point of the alternating current degaussing signal and realizing mode switching of degaussing and residual magnetism detection; and the magnetic shielding device is used for demagnetizing under the action of the alternating current demagnetizing signal and feeding back the residual magnetism state of the preset feature point under the action of the excitation pulse signal. The demagnetization is interrupted at the preset feature points in the demagnetization process, the real-time residual magnetism state is collected, and the demagnetization parameter at the next moment is adjusted after the real-time residual magnetism state is compared with the preset residual magnetism expected value, so that the problem of low efficiency due to the fact that the demagnetization parameter needs to be reset after the process is finished is solved, and the demagnetization efficiency and accuracy are greatly improved.

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 a method for measuring and analyzing residual magnetism characteristics of an iron core. According to the method, a to-be-detected iron core is demagnetized, preset residual magnetism is set, direct-current voltage excitation with opposite polarities, the same amplitude and the same duration is applied to a primary winding of the to-be-detected iron core, and transient current response signals are synchronously collected; two groups of current under positive / negative polarity excitation are extracted, and the residual magnetism direction is judged by comparing the change rate of the current; a curve of equivalent resistance changing along with time is calculated based on forward current and voltage, a resistance value corresponding to a characteristic inflection point moment is selected, the resistance value is substituted into a pre-established residual magnetism-equivalent resistance empirical formula to deduce the magnitude of residual magnetism, and a matched iron core residual magnetism detection and demagnetization integrated system integrates information management, residual magnetism detection, demagnetization and display modules. And closed-loop automation of detection, analysis and demagnetization is realized. According to the method, a magnetic field sensor is not needed, the residual magnetism direction and size can be synchronously obtained in a high-precision and robust mode only through port electric signals, and the method is suitable for on-site off-line or live detection.

The invention discloses a circuit breaker contact structure integrated with a permanent magnet and a vacuum circuit breaker, and relates to the technical field of vacuum circuit breakers, the circuit breaker contact structure integrated with the permanent magnet comprises a contact piece, a contact cup, an insulation sleeve, a permanent magnet ring and a conducting rod, the contact piece and the conducting rod are arranged at the two ends of the contact cup respectively, the insulation sleeve is sleeved outside the contact cup, the permanent magnet ring is sleeved outside the insulation sleeve, and the contact cup is provided with a spiral slot. The vacuum circuit breaker adopts a circuit breaker contact structure integrated with a permanent magnet. Through innovative structural design and material application, the problems that in an existing vacuum circuit breaker contact structure, magnetic field phase lag and residual magnetism affect arc extinguishing are effectively solved, the longitudinal magnetic field control effect is enhanced at the current peak value, the residual magnetism is restrained at the current zero passage, coordination and cooperation of the two are achieved, and the service life of the vacuum circuit breaker is prolonged. The breaking performance and reliability of the vacuum circuit breaker are improved, and the breaking reliability of the vacuum circuit breaker is improved.

The invention provides a Y-rich rare earth permanent magnet and a preparation method and a magnetic performance improving method thereof, and the performance improving method comprises the steps: uniformly mixing to-be-diffused metal powder containing Dy and / or Tb elements with an organic solvent to obtain to-be-diffused alloy liquid; the alloy liquid to be diffused is attached to the surface of the Y-rich rare earth permanent magnet, and the Y-rich rare earth permanent magnet is placed in a vacuum sintering furnace; the Y-rich rare earth permanent magnet is subjected to grain boundary diffusion heat treatment through the vacuum sintering furnace, so that Dy and / or Tb elements are diffused into the surface layer of a main phase lattice of the Y-rich rare earth permanent magnet; and carrying out tempering treatment on the Y-rich rare earth permanent magnet. The problems that the coercive force of an existing Y-containing magnet is difficult to effectively improve, and residual magnetism is easily reduced can be effectively solved.