Field operator base permanent magnet preparation process

Abstract

This invention discloses a process for preparing a reference permanent magnet for a field arithmetic unit, belonging to the field of precision magnetic material preparation technology. This process involves precise raw material proportioning, vacuum induction melting, ultra-high-speed cooling casting, protective single-domain ultrafine powder preparation, precise pressing with a directional magnetic field, multi-stage vacuum sintering and two-stage tempering aging, and high-precision pulse magnetization and shaping. It utilizes rare-earth magnetic elements and iron-based transition metal elements as the main components, combined with lattice-setting and high-temperature domain-stabilizing modification elements, to achieve atomic-level lattice-oriented control of the permanent magnet. The reference permanent magnet prepared by this invention possesses extremely low stray magnetic field, ultra-high magnetic performance uniformity, excellent thermal stability, and structural stability, fully meeting the stringent precision requirements of field arithmetic units for the reference magnetic field source. The process is quantifiable and suitable for large-scale production, filling the gap in the preparation process of precision permanent magnets for field arithmetic units and applicable to the manufacturing of core reference components for various high-end precision field-effect computing devices.

Description

Technical Field

[0001] This invention belongs to the field of precision magnetic material preparation technology, specifically relating to a preparation process for a reference permanent magnet for field arithmetic units, which is particularly suitable for the large-scale manufacturing of high-precision field arithmetic core reference components. Background Technology

[0002] As the core device for precision field signal control and field effect calculation, the field arithmetic unit places extremely high performance requirements on the internal reference permanent magnet: it must have ultra-high magnetic property uniformity, extremely low stray magnetic field, ultra-high magnetocrystalline anisotropy, excellent thermal stability and structural stability to ensure the accuracy, consistency and reliability of field calculation. Existing conventional permanent magnet fabrication processes are mostly designed for general industrial applications. The permanent magnets produced have defects such as insufficient lattice orientation regularity, disordered microscopic magnetic domain arrangement, poor magnetic property uniformity, easy demagnetization at high temperatures, and large stray field interference, which cannot meet the stringent requirements of field arithmetic units for the reference magnetic field source. On the other hand, existing precision magnetic material processes do not perform atomic-level lattice orientation control for the specialized needs of field arithmetic units, making it difficult to achieve high-performance, low-defect, and high-consistency fabrication of reference permanent magnets, thus restricting the performance improvement of field arithmetic unit devices. Therefore, there is an urgent need to develop a dedicated fabrication process for reference permanent magnets for field arithmetic units, to address the shortcomings of existing technologies and meet the application requirements of high-end field arithmetic devices. Summary of the Invention

[0003] Purpose of the invention To address the shortcomings of existing technologies, this invention provides a process for preparing a reference permanent magnet for a field arithmetic unit. Through specific raw material ratios, multi-level directional lattice control, refined heat treatment, and precise magnetization processes, a special reference permanent magnet for a field arithmetic unit with high regularity, low stray field, high magnetic performance uniformity, and high thermal stability is prepared, solving the technical problem that existing processes cannot meet the high-precision reference magnetic field requirements of field arithmetic units. Technical solution A process for fabricating a reference permanent magnet for a field arithmetic unit includes the following steps: Precise proportioning and mixing of raw materials Based on atomic percentage, select 11.5%-12.5% ​​of rare earth main magnetic elements, 82%-84% of high saturation magnetization iron-based transition metal elements, 3.5%-5.5% of lattice orientation and shaping doping elements, and 0.5%-1.0% of high-temperature domain stabilizing modifying elements. Place all raw materials in a vacuum mixer and mix at a rate of 300r / min-500r / min for 40min-60min to obtain a uniformly mixed raw material. Among them, the main rare earth magnetic elements are a mixture of neodymium and dysprosium in a mass ratio of 7:1 to 9:1, the iron-based transition metal elements are a mixture of pure iron and cobalt in a mass ratio of 20:1, the lattice orientation and shaping doping elements are a mixture of boron and carbon, and the high-temperature domain stabilizing modifying elements are a mixture of niobium and copper. Vacuum induction melting and rapid solidification Transfer the mixed raw materials to a vacuum induction melting furnace, evacuate the furnace to a vacuum degree of ≤5×10⁻³Pa, heat to 1480℃-1520℃, and hold the temperature for 45min-55min to ensure that the raw materials are completely melted and alloyed. The molten alloy liquid is fed at a rate of 8×10³℃ / s-1.2×10 4 Rapid solidification casting at an ultra-high rate of ℃ / s yields alloy rapidly solidified sheets with a thickness of 0.2mm-0.4mm. The formation of pre-oriented oriented preforms within the alloy sheets is controlled, with grain size controlled between 30μm and 60μm. Preparation of single-domain ultrafine powder The alloy rapid solidification sheets were subjected to coarse crushing and air jet milling to prepare single magnetic domain level alloy ultrafine powder. The powder particle size distribution was controlled to be 2.5μm-4.0μm and the powder oxygen content was ≤300ppm. The entire ultrafine grinding process is conducted under a protective argon atmosphere to prevent powder oxidation and ensure the integrity of the powder lattice. Precision molding using directional magnetic field Single-domain alloy ultrafine powder is placed into a special mold, and a pulsed directional strong magnetic field is applied for orientation pressing. The magnetic field strength is set to 4T-6T, and the pressing direction is completely matched with the direction required by the reference magnetic field of the field calculator. The forming pressure is 200MPa-280MPa, and the holding time is 10s-15s, to obtain a high-orientation permanent magnet green blank. Maintaining a constant magnetic field during the pressing process ensures that the magnetic domains inside the powder are precisely arranged along a single crystal orientation. Multi-stage vacuum sintering and aging treatment The permanent magnet green blank is transferred to a vacuum sintering furnace and evacuated to a vacuum level ≤8×10⁻. 4 Pa, using a three-stage heating and sintering method: First stage: Increase the temperature to 650℃-700℃ at a rate of 5℃ / min, and hold for 1h-1.5h; Second stage: Increase the temperature to 1070℃-1090℃ at a rate of 10℃ / min, and hold for 2.5h-3.5h; Third stage: Cool to room temperature with the furnace; After sintering, a two-stage tempering and aging treatment is carried out. The first stage tempering temperature is 920℃-940℃, and the holding temperature is 1.5h-2h. The second stage tempering temperature is 570℃-590℃, and the holding temperature is 2.5h-3h. This process eliminates lattice stress and improves lattice regularity and structural stability. High-precision pulse magnetization shaping The heat-treated permanent magnet blank is placed in a special magnetization fixture, and a strong pulsed magnetic field of 5T-7T in the same direction as the directional pressing is applied for precise magnetization. The magnetization time is controlled within 5ms-10ms to ensure that the internal lattice magnetic domains are completely oriented and regular, thus obtaining the reference permanent magnet for the field arithmetic unit. Beneficial effects This invention addresses the specific reference magnetic field requirements of field arithmetic units by achieving atomically ordered arrangement of permanent magnets through precise raw material ratios and multi-level lattice orientation control. The prepared reference permanent magnets possess extremely low stray magnetic fields, ultra-high magnetic performance uniformity, and ultra-high magnetocrystalline anisotropy, fully meeting the stringent precision requirements of field arithmetic units for reference magnetic field sources. By employing ultra-high-speed condensation, protective ultra-fine powder preparation, and a three-stage sintering process, the oxidation of raw materials and lattice distortion are effectively avoided, significantly improving the thermal and structural stability of the permanent magnet and ensuring the reliability and consistency of the field arithmetic unit during long-term operation. The entire process is quantifiable and can be mass-produced without any special or demanding procedures. The prepared reference permanent magnets are compatible with the core reference components of various field arithmetic units, filling the gap in the domestic process for preparing precision permanent magnets for field arithmetic units. They can be directly applied to the field of high-end precision field-effect computing devices.

Claims

1. A process for fabricating a reference permanent magnet for a field arithmetic unit, characterized in that, Includes the following steps: (1) Select 11.5%-12.5% ​​of rare earth main magnetic elements, 82%-84% of iron-based transition metal elements, 3.5%-5.5% of lattice orientation and shaping doping elements, and 0.5%-1.0% of high-temperature domain stabilizing modification elements according to atomic percentage, and mix them to obtain a uniform mixed raw material; (2) The mixed raw materials are vacuum melted and held at 1480℃-1520℃ for 45min-55min, then melted at 8×10³℃ / s-1.2×10 4 Rapid solidification at a rate of ℃ / s yields rapidly solidifying alloy flakes. (3) The alloy rapid solidification sheets were pulverized by protective air jet mill to obtain single-domain alloy ultrafine powder with a particle size of 2.5μm-4.0μm; (4) The alloy ultrafine powder is placed in a 4T-6T directional pulsed magnetic field and pressed with a pressure of 200MPa-280MPa to obtain a permanent magnet green blank; (5) After the permanent magnet green blank is subjected to multi-stage vacuum sintering and two-stage tempering and aging treatment, a 5T-7T unidirectional pulse magnetic field is applied to magnetize it to obtain the reference permanent magnet of the field arithmetic unit.

2. The preparation process according to claim 1, characterized in that, In step (1), the rare earth main magnetic elements are neodymium and dysprosium mixed in a mass ratio of 7:1 to 9:1, the iron-based transition metal elements are pure iron and cobalt mixed in a mass ratio of 20:1, the lattice orientation and shaping doping elements are a mixture of boron and carbon, and the high-temperature domain stabilizing modification elements are a mixture of niobium and copper.

3. The preparation process according to claim 1, characterized in that, In step (2), the vacuum degree of vacuum melting is ≤5×10⁻³Pa, and the thickness of the alloy quick-solidification sheet is 0.2mm-0.4mm.

4. The preparation process according to claim 1, characterized in that, In step (3), the ultrafine grinding process is carried out under an argon protective atmosphere, and the oxygen content of the powder is ≤300ppm.

5. The preparation process according to claim 1, characterized in that, In step (5), the vacuum degree of multi-stage vacuum sintering is ≤8×10⁻ 4 Pa adopts a three-stage heating sintering process, with secondary tempering temperatures of 920℃-940℃ and 570℃-590℃ respectively.