Sintered high-abundance rare earth Ce magnet and preparation method thereof

Abstract

The invention relates to the technical field of rare earth permanent magnets, in particular to a sintered high-abundance rare earth Ce magnet and a preparation method thereof. The invention provides a sintered high-abundance rare earth Ce magnet. The magnet is prepared by mixing and sintering RE1-Fe-M1-B hard magnetic phase alloy powder, RE2-Fe-M2-B hard magnetic phase alloy powder and PN alloy powder, the particle size ratio of the RE1-Fe-M1-B hard magnetic phase alloy powder to the RE2-Fe-M2-B hard magnetic phase alloy powder ranges from 0.1 to 0.9; and the particle size ratio of the PN alloy powder to the RE1-Fe-M1-B hard magnetic phase alloy powder is 0.1 to 1. According to the sintered high-abundance rare earth Ce magnet, the proportion of Ce in the total adding amount of rare earth elements is high, and the raw material cost is remarkably reduced; the microstructure is obviously optimized, the rare earth-rich phase is continuously distributed along the grain boundary, the magnetic exchange coupling effect between main phase grains is effectively isolated, meanwhile, the magnetocrystalline anisotropy field intensity of the surface layer of the main phase grains is improved, and the magnetic performance is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of rare earth permanent magnets, and particularly to a sintered high-abundance rare earth Ce magnet and a preparation method thereof. Background Art

[0002] Clean energy industries such as new energy vehicles, wind power generation, and variable-frequency air conditioners are continuously expanding, greatly driving the increasing demand for neodymium iron boron permanent magnets. As the rare earth functional material with the largest rare earth consumption, the neodymium iron boron permanent magnet material industry will drive the continuous increase in the demand for rare earths in the future, exacerbating the continuous rise in the demand for rare earth metal raw materials such as Pr, Nd, Dy, and Tb. This will not only increase the production cost of magnets and reduce the product profit margin, but also lead to the backlog of the co-associated highest natural abundance rare earth Ce element with rich reserves and limited applications.

[0003] Ce is the rare earth element with the highest abundance in nature. Among the world's proven rare earth minerals, Ce has the highest reserves, accounting for up to 50% in rare earth minerals. The market supply is greater than the demand, the price is low, and the added value of the corresponding rare earth products is low. Using the highest natural abundance rare earth element Ce to replace part of the rare earth raw materials Pr and Nd can not only significantly reduce the magnet cost and improve the competitiveness of permanent magnet products, but also reduce the backlog of the highest natural abundance rare earth and realize the high-quality utilization of rare earth elements.

[0004] However, due to Ce 2 Fe 14 The saturation magnetization, magnetocrystalline anisotropy field, and Curie temperature (4πM s = 11.7 kGs, H a = 26 kOe, T c = 424 K) of the Ce 2 Fe 14 B phase are significantly lower than those of the Pr s = 15.6 kGs, H a = 75 kOe, T c = 565 K) and Nd 2 Fe 14 B phase (4πM s = 16.0 kGs, H a = 73 kOe, T c = 585 K). This means that replacing Pr / Nd with Ce element will not only reduce the main intrinsic magnetic properties of the hard magnetic phase, but also weaken the temperature stability of the high-abundance RE-Fe-B permanent magnet material. In addition, the increase in the Ce content or proportion in the magnet will lead to a decrease in the volume fraction of the hard magnetic phase, and at the same time make the grain boundary phase distributed in a lump shape, deteriorating the microstructure and seriously reducing the magnetic properties.

[0005] Therefore, existing sintered high-abundance Ce magnets with a high Ce content / ratio generally have poor microstructures and inferior magnetic properties. Summary of the Invention

[0006] In view of the above analysis, embodiments of the present invention aim to provide a sintered high-abundance rare earth Ce magnet and a preparation method thereof, so as to alleviate at least one of the problems such as the imbalance in the utilization of existing rare earth resources, the oversupply of raw material Ce, the high cost of sintered NdFeB permanent magnets, the lack of continuous grain boundary phases in the magnet due to a high Ce content or ratio, the deterioration of the microstructure, and the decline in magnetic properties.

[0007] The present invention provides a sintered high-abundance rare earth Ce magnet, which is prepared by mixing and sintering RE 1 -Fe-M 1 -B hard magnetic phase alloy powder, RE 2 -Fe-M 2 -B hard magnetic phase alloy powder, and PN alloy powder; The particle size ratio of the RE 1 -Fe-M 1 -B hard magnetic phase alloy powder and the RE 2 -Fe-M 2 -B hard magnetic phase alloy powder is 0.1 to 0.9; The particle size ratio of the PN alloy powder and the RE 1 -Fe-M 1 -B hard magnetic phase alloy powder is 0.1 to 1; Preferably, each type of powder is prepared by a jet mill; Among them, RE 1 is neodymium element; Or RE 1 contains neodymium element and at least one of praseodymium, gadolinium, terbium, dysprosium, and holmium elements, preferably one or two of praseodymium and dysprosium; Furthermore, the mass ratio of neodymium element in RE 1 ≥50%; RE 2 is cerium element; Or RE 2 contains cerium element and at least one of lanthanum, praseodymium, neodymium, gadolinium, terbium, dysprosium, and holmium elements, preferably one or several of lanthanum, neodymium, and praseodymium; Furthermore, the mass ratio of cerium element in RE 2 ≥50%; PN includes at least one of praseodymium and neodymium elements; Among them, the ratio of cerium element to the total mass of rare earth elements is: Ce / (RE 1 +RE 2 +PN)=0.18 to 0.87; M 1 Including cobalt, copper, gallium; or M 1 including at least one of cobalt, copper, gallium, aluminum, titanium, and zirconium; M 2 Including cobalt, copper, gallium; or M 2 Includes at least one of cobalt, copper, gallium, aluminum, titanium and zirconium.

[0008] Preferably, M 1 and M 2 The composition is exactly the same; particularly preferably, the mass proportion of each element in the corresponding alloy is the same within the error range, illustratively, the error floating range is ±10%, for example, the mass content of a certain element X in the corresponding alloy is 1±0.1%.

[0009] Preferably, the RE 1 -Fe-M 1 -B hard magnetic phase alloy powder and RE 2 -Fe-M 2 -B hard magnetic phase alloy powder particle size ratio is 0.2 to 0.8; the PN alloy powder and the RE 1 -Fe-M 1 -B hard magnetic phase alloy powder particle size ratio is 0.2 to 0.8.

[0010] Furthermore, the RE 1 -Fe-M 1 -B Hard Magnetic Phase Alloy Powder Quality and RE 2 -Fe-M 2 -B hard magnetic phase alloy powder mass ratio is 1~9:1~9; The PN alloy powder accounts for the RE 1 -Fe-M 1 -B hard magnetic phase alloy powder, RE 2 -Fe-M 2 -0.1 to 5% of the sum of the mass of B hard magnetic phase alloy powder and PN alloy powder.

[0011] Preferably, it is characterized in that the RE 1 -Fe-M 1 -B Hard Magnetic Phase Alloy Powder Quality and RE 2 -Fe-M 2 -B hard magnetic phase alloy powder mass ratio is 2 to 4.5:5.5 to 8; The PN alloy powder accounts for the RE 1 -Fe-M 1 -B hard magnetic phase alloy powder, RE 2 -Fe-M 2 -0.5~2% of the sum of the mass of B hard magnetic phase alloy powder and PN alloy powder.

[0012] Preferably, the PN alloy is PN-M 3 alloy, where M 3 is at least one of cobalt, copper, and gallium; and the proportion of PN is 60-100 wt.%, and M 3 has a proportion of 0-40 wt.%.

[0013] Preferably, the specific composition of the RE 1 -Fe-M 1 -B hard magnetic phase alloy is: RE 1 : 25-35 wt.%, Al: 0.0-1.5 wt.%, Ti: 0.0-1.5 wt.%, Co: 0.1 - 1.1 wt.%, Cu: 0.1-1.1 wt.%, Ga: 0.1-1.1 wt.%, Zr: 0.0-1.5 wt.%, B: 0.9-1.5 wt.%, and the balance is the transition metal Fe element and impurity elements, where Al, Ti, Co, Cu, Ga, Zr are elements within M 1 ; The RE 2 -Fe-M 2 -B hard magnetic phase alloy has a specific composition of: RE 2 : 25-35 wt.%, Al: 0.0-1.5 wt.%, Ti: 0.0-1.5 wt.%, Co: 0.1-1.1 wt.%, Cu: 0.1-1.1 wt.%, Ga: 0.1-1.1 wt.%, Zr: 0.0-1.5 wt.%, B: 0.9-1.5 wt.%, and the balance is the transition metal Fe element and impurity elements, where Al, Ti, Co, Cu, Ga, Zr are elements within M 2 ; Among them, the unaccurately measured La < 0.15 wt.% and Ce < 0.15 wt.% in the two types of hard magnetic alloys. The unaccurately measured La and Ce elements are regarded as impurity elements. It should be noted that the unaccurately measured La and Ce elements refer to extremely small amounts of La and Ce that cannot be included in the main components and are classified as impurity elements in the composition.

[0014] Furthermore, the specific composition of the magnet by mass percentage is: RE 1 +RE 2+PN: 25 - 38 wt.%; Al: 0.0 - 1.5 wt.%, Ti: 0.0 - 1.5 wt.%, Co: 0.1 - 6.75 wt.%, Cu: 0.1 - 3.05 wt.%, Ga: 0.1 - 3.05 wt.%, Zr: 0.0 - 1.5 wt.%, B: 0.9 - 1.5 wt.%, with the balance being the transition metal Fe element and impurity elements.

[0015] Preferably, the RE 1 -Fe-M 1 -B hard magnetic phase alloy powder, RE 2 -Fe-M 2 -B hard magnetic phase alloy powder and the PN alloy powder have an average particle size of 0.5 - 6.5 μm.

[0016] Preferably, the average particle size of the powder is 1 - 5 μm.

[0017] The present invention also provides a method for preparing the magnet, First, prepare RE 1 -Fe-M 1 -B hard magnetic phase alloy powder, RE 2 -Fe-M 2 -B hard magnetic phase alloy powder and the PN alloy powder according to a preset formula and particle size ratio; the average particle size of the powder is 0.5 - 6.5 μm; Mix the three powders in proportion and then perform pressing, sintering and aging heat treatment to finally obtain the sintered high-abundance rare earth Ce magnet.

[0018] Furthermore, the preparation method further includes a grain boundary diffusion treatment step. After the surface of the sintered high-abundance rare earth Ce magnet after sintering and aging heat treatment is ground and activated, a diffusion source containing heavy rare earth elements is attached, and after diffusion heat treatment, a grain boundary diffusion sintered high-abundance Ce magnet is obtained.

[0019] The present invention also discloses an application of the above magnet, and the magnet is applied to the manufacture of magnetic components in rare earth permanent magnet motors, intelligent consumer electronic products, and medical devices.

[0020] Compared with the prior art, the present invention can at least achieve one of the following beneficial effects: 1. In the sintered high-abundance rare earth Ce magnet provided by the present invention, the ratio of Ce in the added rare earth elements is high, the grain boundary phase can be continuously distributed between the grains, and at the same time, the distribution of rare earth elements in the main phase grains is regulated, the magnetic crystal anisotropy field strength in the surface layer region of the grains is improved, the coercivity is improved, and the magnet has excellent magnetic properties.

[0021] The present invention regulates RE 1 -Fe-M 1-B hard magnetic phase alloy powder, RE 2 -Fe-M 2 -B hard magnetic phase alloy powder, PN-M 3 The addition ratio and particle size ratio among the three alloy powders can, on the one hand, optimize the quantity ratio and grain volume ratio between the two different intrinsically magnetic property main phase grains of the RE main phase and the RE main phase in the dual-main-phase magnet, thereby constructing the magnetic energy potential difference between different main phase grains and hindering the expansion of reverse magnetization domains. 1 main phase and RE 2 On the other hand, it improves the local relative distribution amount of the PN (or PN-M

[0022] ) alloy powder and the RE-Fe-M-B hard magnetic phase alloy powder with high intrinsic magnetic properties in the green body, which is conducive to the uniform distribution of the RE-rich phase in the magnet and reduces the proportion of massive RE-rich phases in the magnet after sintering heat treatment; it is conducive to constructing a continuous and uniformly distributed thin layer of RE-rich grain boundary phase in the magnet, such as the white rare-earth-rich phase continuously distributed along the grain boundaries in 3 ), which can effectively isolate the magnetic exchange coupling effect between the main phase grains, reduce grain boundary defects, and inhibit the nucleation of reverse magnetization domains; it is conducive to simultaneously significantly increasing the concentration of rare-earth elements with high intrinsic magnetic properties in the RE-rich epitaxial layer and the RE-rich 1 -Fe-M 1 -B hard magnetic phase alloy powder, thereby increasing the magnetic anisotropy field strength of the RE-rich epitaxial layer and the RE-rich Figure 2 epitaxial layer on the surface of the main phase grains, inhibiting the nucleation of reverse magnetization domains, and then significantly improving the coercivity of the magnet, realizing the preparation of a dual-main-phase high-added-amount sintered high-abundance Ce magnet. 1 epitaxial layer and the RE-rich 2 epitaxial layer, so as to improve the magnetic anisotropy field strength of the RE-rich epitaxial layer and the RE-rich 1 epitaxial layer on the surface of the main phase grains, inhibit the nucleation of reverse magnetization domains, and then significantly improve the coercivity of the magnet, realizing the preparation of a dual-main-phase high-added-amount sintered high-abundance Ce magnet. 2 epitaxial layer, inhibit the nucleation of reverse magnetization domains, and then significantly improve the coercivity of the magnet, realizing the preparation of a dual-main-phase high-added-amount sintered high-abundance Ce magnet.

[0023] 2. The magnet preparation method provided by the present invention is relatively simple, and the microstructural characteristics of the prepared magnet are conducive to improving the effect of grain boundary diffusion.

[0024] During the preparation process of the sintered high-abundance Ce magnet of the present invention, by adding the low-melting-point PN-M 3 alloy powder, the wettability and fluidity of the grain boundary phase are improved, and a continuous and uniformly distributed grain boundary phase is constructed, such as the white rare-earth-rich phase continuously distributed along the grain edges in Figure 3 ), increasing the grain boundary diffusion channels in the high-added-amount high-abundance sintered magnet, thus promoting the depth and concentration of the heavy rare-earth element diffusion into the magnet interior, being conducive to increasing the heavy rare-earth content on the surface layer of the main phase grains inside the magnet, promoting the formation of a composite phase with a high magnetic anisotropy field, increasing the reverse magnetization domain nucleation field on the surface of the main phase grains, and thus further improving the coercivity of the magnet. In addition, a composite phase microstructure with consistent composition and structure is formed on the surface layer of the main phase grains throughout the magnet.

[0025] 3. Through the diffusion treatment of the sintered high-abundance Ce magnet, the present invention realizes the preparation of a sintered high-abundance Ce magnet with low HRE and high coercivity. Meanwhile, by using the highest natural-abundance rare-earth element Ce to replace Pr / Nd elements to prepare sintered Nd-Fe-B permanent magnets, the raw material cost pressure of rare-earth permanent magnets can be significantly reduced, the competitiveness of rare-earth permanent magnet products can be improved, the backlog of Ce can be reduced, the high-quality utilization of high-abundance rare-earth elements can be realized, the resource advantages of high-abundance rare-earth in China can be fully utilized, and the balance and sustainable development of rare-earth resources can be promoted.

[0026] In the present invention, the above technical solutions can also be combined with each other to achieve more preferred combination schemes. Other features and advantages of the present invention will be described in the subsequent specification, and some advantages can be made obvious from the specification or understood by implementing the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the content specifically pointed out in the specification and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The drawings are only for the purpose of showing specific embodiments and are not considered to be a limitation of the present invention. Throughout the drawings, the same reference signs represent the same components; Figure 1 It is a schematic diagram of the microscopic organizational structure of the sintered high-abundance Ce magnet; Figure 2 It is a microscopic electron microscope photograph (10μm level) of the sintered high-abundance Ce magnet in Example 1; Figure 3 It is a microscopic electron microscope photograph (5μm level) of the sintered high-abundance Ce magnet in Example 1. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] The following will specifically describe the preferred embodiments of the present invention in conjunction with the drawings. The drawings form a part of this application and are used together with the embodiments of the present invention to explain the principle of the present invention, rather than to limit the scope of the present invention.

[0029] Based on the current situation that an increase in the Ce content or proportion in existing Nd-Fe-B permanent magnets will cause negative impacts such as the lack of continuous grain boundary phase, deterioration of the microscopic structure, and decline in magnetic properties in permanent magnets, the R & D personnel of the present invention have conducted in-depth research and analysis, located the following defects, and proposed possible solutions: (1) As the addition amount of the Ce element increases, the proportion of the thin-layer grain boundary phase in the RE-Fe-B rare-earth permanent magnet decreases, the grain boundary defects increase, and the direct contact between the main-phase grains strengthens the magnetic exchange coupling effect between them, resulting in a significant reduction in the magnetic properties of the magnet. In addition, due to La 2 Fe 14 B and Ce 2 Fe 14 B have much lower intrinsic magnetic properties than Pr2 Fe 14 B and Nd 2 Fe 14 When the contents of B and Ce elements increase, the magnetocrystalline anisotropy field of the main phase grains of the magnet will be further reduced. For various reasons, the addition amount of the high-abundance rare earth Ce element in the magnet and the application range of the magnet are severely restricted.

[0030] (2) In the prior art, some technicians have tried to adopt the dual-main-phase or multi-main-phase process, and through technical means such as regulating the valence state of rare earth elements, assembling and compounding multi-permanent magnet main-phase magnets, adding and modifying the grain boundaries, and adding heavy rare earth components, in order to improve the magnetic properties. However, due to the fact that the microstructural organization of sintered rare earth permanent magnets and the intrinsic magnetic properties of the main phase deteriorate sharply with the increase of the Ce addition amount, it has become a key technical problem to be solved urgently to ensure that the permanent magnet has good microstructural organization and magnetic properties while increasing the Ce addition amount.

[0031] Therefore, based on the dual-main-phase process, the present invention designs a multi-element alloying system (selecting a suitable hard magnetic phase alloy and additionally adding a PN alloy), the particle size and addition ratio of the alloy powder, regulates the microstructure in the magnet, constructs the magnetic energy potential difference between different main phase grains, optimizes the grain boundary structure, and obtains a sintered high-abundance Ce magnet with high cost performance and high addition amount. The proportion of the high-abundance rare earth Ce content in the magnet to the total rare earth amount can reach more than 80% (up to 87% at most). The rare earth-rich phase can be continuously distributed along the grain boundaries, separating adjacent main phase grains, while reducing the proportion of the grain boundary phase with massive agglomeration distribution, enhancing the magnetocrystalline anisotropy field on the surface of the main phase, and significantly improving the magnetic properties compared with the magnets prepared by the traditional conventional process.

[0032] The present invention provides a sintered high-abundance rare earth Ce magnet, and the sintered high-abundance rare earth Ce magnet is prepared by mixing and sintering RE 1 -Fe-M 1 -B hard magnetic phase alloy powder, RE 2 -Fe-M 2 -B hard magnetic phase alloy powder and PN alloy powder; The RE 1 -Fe-M 1 -B hard magnetic phase alloy powder and the RE 2 -Fe-M 2 -B hard magnetic phase alloy powder have a particle size ratio of 0.1 to 0.9; The PN alloy powder and the RE 1 -Fe-M 1 -B hard magnetic phase alloy powder have a particle size ratio of 0.1 to 1; The present invention regulates the RE 1 -Fe-M 1 -B hard magnetic phase alloy powder, RE2 -Fe-M 2 -B hard magnetic phase alloy powder, PN-M 3 The addition ratio and particle size ratio among the three alloy powders are used to construct a continuously and uniformly distributed thin-layer RE-rich grain boundary phase in the magnet, isolating the magnetic exchange coupling effect between the main phase grains, reducing grain boundary defects, and at the same time promoting the uniform distribution of the RE-rich phase in the magnet, reducing the proportion of massive RE-rich phase in the magnet after sintering heat treatment, thereby effectively improving the remanence and coercivity of the high-addition and high-abundance Ce sintered magnet; Preferably, each type of powder is prepared by a jet mill; Among them, RE 1 is neodymium element; or RE 1 contains neodymium element and at least one of praseodymium, gadolinium, terbium, dysprosium, and holmium elements, preferably one or two of praseodymium and dysprosium; Furthermore, the mass ratio of neodymium element in RE 1 ≥50%; RE 2 is cerium element; or RE 2 contains cerium element and at least one of lanthanum, praseodymium, neodymium, gadolinium, terbium, dysprosium, and holmium elements, preferably one or several of lanthanum, neodymium, and praseodymium; Furthermore, the mass ratio of cerium element in RE 2 ≥50%; PN includes at least one of praseodymium and neodymium elements; M 1 includes cobalt, copper, and gallium; or M 1 includes cobalt, copper, gallium, and at least one of aluminum, titanium, and zirconium; M 2 includes cobalt, copper, and gallium; or M 2 includes cobalt, copper, gallium, and at least one of aluminum, titanium, and zirconium.

[0033] Among them, the functions of each element are as follows: Fe, B: The main components of the magnet, and are essential main elements for forming the hard magnetic main phase in the RE-Fe-B alloy.

[0034] RE 1 : Neodymium element is an essential main element for forming the hard magnetic main phase in the RE 1 -Fe-M 1 -B alloy, and has high intrinsic magnetic properties; the addition of other optional components such as praseodymium element can reduce the raw material cost, and the addition of elements such as gadolinium, terbium, dysprosium, and holmium can effectively improve the high-temperature resistance characteristics or coercivity of the magnet by enhancing the intrinsic magnetic characteristics of the hard magnetic phase.

[0035] M1 , M 2 : It can reduce the melting point of the grain boundary phase and effectively improve the wettability of the molten grain boundary phase during the heat treatment process, thereby contributing to optimizing the distribution of the grain boundary phase.

[0036] RE 2 : Cerium element is an essential main element for forming the hard magnetic main phase in the RE 2 -Fe-M 2 -B alloy; The addition of other optional components such as lanthanum element can reduce the raw material cost, and the addition of elements such as praseodymium, neodymium, gadolinium, terbium, dysprosium, holmium, etc. can effectively improve the high-temperature resistance or coercivity of the magnet by enhancing the intrinsic magnetic properties of the hard magnetic phase.

[0037] It is worth highlighting that: PN: The PN element aims to further increase the content of praseodymium and neodymium elements in the surface layer of the main phase grains, promote the magnetic hardening of the surface layer of the main phase grains, inhibit the nucleation of reverse magnetization domains, and thus improve the magnet performance.

[0038] M 3 Element: The addition of cobalt element can increase the content of Co element in the main phase grains, raise the Curie temperature of the main phase, and improve the high-temperature resistance of the magnet.

[0039] The copper and gallium elements in the PN alloy powder can directly act between the grains, significantly increase the content of Cu and Ga elements in the grain boundary, further improve the wettability of the molten grain boundary phase, promote the formation of a continuous and uniform thin RE-rich phase layer in the magnet, thereby improving the grain boundary phase distribution, optimizing the microstructure, and enhancing the coercivity of the magnet.

[0040] In short, since the PN-M 3 alloy powder is distributed between the hard magnetic phase grains and is the main source of the molten liquid grain boundary phase during the sintering process, adding Cu and Ga in this way enables these elements to preferentially concentrate and enrich in the grain boundary, obtaining better magnetic properties.

[0041] Preferably, M 1 and M 2 have exactly the same composition; Particularly preferably, the mass ratios of each element in the corresponding alloys are the same within the error range. Exemplarily, the error floating range is ±10%. For example, the mass content of a certain element X in the corresponding alloy is 1 ± 0.1%.

[0042] Preferably, the particle size ratio of the RE 1 -Fe-M 1 -B hard magnetic phase alloy powder and the RE 2 -Fe-M 2 -B hard magnetic phase alloy powder is 0.2 - 0.8; When RE1 -Fe-M 1 -B hard magnetic phase alloy powder and RE 2 -Fe-M 2 When the particle size ratio of the -Fe-M-B hard magnetic phase alloy powder is lower than 0.2, the powder is extremely easy to oxidize and difficult to prepare and transfer. It will not only reduce the magnet performance, but also increase the manufacturing cost. When it exceeds 0.8, the proportion of the low magnetic crystal anisotropy rich Ce epitaxial layer on the surface layer of the -Fe-M-B hard magnetic phase grains in the sintered magnet increases, weakening the hard magnetism of the main phase grains and resulting in poor magnet performance. 1 -Fe-M-B hard magnetic phase grain surface layer of the low magnetic crystal anisotropy rich Ce epitaxial layer ratio increases, weakening the hard magnetism of the main phase grains, poor magnet performance.

[0043] The PN alloy powder and the RE 1 -Fe-M 1 The particle size ratio of the -Fe-M-B hard magnetic phase alloy powder is 0.2 - 0.8; When the PN alloy powder and the RE 1 -Fe-M 1 When the particle size ratio of the -Fe-M-B hard magnetic phase alloy powder is lower than 0.2, the powder is extremely easy to oxidize and difficult to prepare and transfer. It will not only reduce the magnet performance, but also increase the manufacturing cost. When it exceeds 0.8, the proportion of the massive grain boundary phase in the sintered magnet increases, weakening the volume fraction of the hard magnetic phase and resulting in poor magnet performance.

[0044] Furthermore, the RE 1 -Fe-M 1 The mass ratio of the -Fe-M-B hard magnetic phase alloy powder to the RE 2 -Fe-M 2 -B hard magnetic phase alloy powder is 1 - 9:1 - 9; The PN alloy powder accounts for 0.1 - 5% of the sum of the masses of the -Fe-M-B hard magnetic phase alloy powder, RE 1 -Fe-M 1 -B hard magnetic phase alloy powder, RE 2 -Fe-M 2 -B hard magnetic phase alloy powder and the PN alloy powder, such as 0.1%, 0.5%, 1%, 1.5%, 2%, 3%, 4%, 5%.

[0045] Preferably, it is characterized in that the mass ratio of the -Fe-M-B hard magnetic phase alloy powder to the RE 1 -Fe-M 1 -B hard magnetic phase alloy powder is 2 - 4.5:5.5 - 8; 2 -Fe-M 2 -B hard magnetic phase alloy powder is 2 - 4.5:5.5 - 8; The PN alloy powder accounts for the -Fe-M-B hard magnetic phase alloy powder, RE 1 -Fe-M 1 -B hard magnetic phase alloy powder, RE 2 -Fe-M 20.5 to 2% of the sum of the masses of the -B hard magnetic phase alloy powder and the PN alloy powder.

[0046] Preferably, the PN alloy is PN-M 3 alloy, where M 3 is at least one of cobalt, copper, and gallium; and the proportion of PN is 60 to 100 wt.%, and M 3 has a proportion of 0 to 40 wt.%.

[0047] Preferably, the specific composition of the RE 1 -Fe-M 1 -B hard magnetic phase alloy is: RE 1 : 25 to 35 wt.%, Al: 0.0 to 1.5 wt.%, Ti: 0.0 to 1.5 wt.%, Co: 0.1 to 1.1 wt.%, Cu: 0.1 to 1.1 wt.%, Ga: 0.1 to 1.1 wt.%, Zr: 0.0 to 1.5 wt.%, B: 0.9 to 1.5 wt.%, and the balance is the transition metal Fe element and impurity elements, where Al, Ti, Co, Cu, Ga, Zr are elements within M 1 within; The RE 2 -Fe-M 2 -B hard magnetic phase alloy has a specific composition of: RE 2 : 25 to 35 wt.%, Al: 0.0 to 1.5 wt.%, Ti: 0.0 to 1.5 wt.%, Co: 0.1 to 1.1 wt.%, Cu: 0.1 to 1.1 wt.%, Ga: 0.1 to 1.1 wt.%, Zr: 0.0 to 1.5 wt.%, B: 0.9 to 1.5 wt.%, and the balance is the transition metal Fe element and impurity elements, where Al, Ti, Co, Cu, Ga, Zr are elements within M 2 within; Among them, in the two types of hard magnetic alloys, La < 0.15 wt.%, Ce < 0.15 wt.%, and both La and Ce elements are regarded as impurity elements.

[0048] Furthermore, the specific composition of the magnet by mass percentage is: RE 1 +RE 2 +PN: 25 to 38 wt.%, where Ce / (RE 1 +RE 2+PN)=0.18~0.87; Al: 0.0~1.5wt.%, Ti: 0.0~1.5wt.%, Co: 0.1~6.75wt.%, Cu: 0.1~3.05wt.%, Ga: 0.1~3.05wt.%, Zr: 0.0~1.5wt.%, B: 0.9~1.5wt.%, and the remainder is transition metal Fe element and impurity elements.

[0049] Preferably, the RE 1 -Fe-M 1 -B hard magnetic phase alloy powder, RE 2 -Fe-M 2 The average particle size of the -B hard magnetic phase alloy powder and the PN alloy powder is 0.5 to 6.5 μm.

[0050] Preferably, the average particle size of the powder is 1 to 5 μm.

[0051] The present invention also provides a method for preparing the magnet. First, prepare RE according to the preset formula and particle size ratio 1 -Fe-M 1 -B hard magnetic phase alloy powder, RE 2 -Fe-M 2 -B hard magnetic phase alloy powder and PN alloy powder, the average particle size of the powder is 0.5 to 6.5 μm; The three powders are mixed in proportion, pressed and molded, and sintered and subjected to aging heat treatment to finally obtain the sintered high-abundance rare earth Ce magnet.

[0052] Specifically, the various alloy powders can be directly purchased, customized or prepared by oneself. When preparing the above powders by oneself, various powders with more uniform texture and better performance can be obtained by preparing according to the following preparation method.

[0053] A method for preparing various alloy powders, specifically comprising the following steps: (1) Prepare RE separately 1 -Fe-M 1 -B hard magnetic phase alloy sheet, RE 2 -Fe-M 2 -B hard magnetic phase alloy sheet and PN-M 3 Alloy sheet; Among them, RE 1 -Fe-M 1 -B hard magnetic phase alloy is a kind of alloy containing Nd, Fe, M 1 The raw materials of element B and element B are prepared into alloy sheets through batching, smelting, rapid solidification and cooling; RE 2 -Fe-M 2The -B hard magnetic phase alloy sheet is prepared by weighing and proportioning raw materials containing Ce element, Fe element, M 2 element, and B element, followed by melting, rapid solidification, and cooling to form the alloy sheet; Optionally, the preparation process of the above two hard magnetic phase alloy sheets is as follows: Weigh and proportion the raw materials according to the ratio, melt them under the protection of an inert gas, and at a certain casting temperature, pour the molten alloy liquid onto a rapidly rotating chill roll to prepare the alloy sheet after cooling; Furthermore, the inert gas is nitrogen or argon, preferably argon; the casting temperature is 1050 - 1550 °C, preferably 1150 - 1500 °C; the rotational speed of the chill roll is 15 - 70 rpm, preferably 25 - 55 rpm; the average thickness of the alloy sheet is 80 - 450 μm; Preferably, the raw materials are pure metals / substances or alloys containing RE 1 , RE 2 , Fe, M 1 , M 2 , and B. More preferably, the raw material of the B element is an alloy containing B.

[0054] It should be noted that the preparation processes of the RE 1 -Fe-M 1 -B hard magnetic phase alloy sheet and the RE 2 -Fe-M 2 -B hard magnetic phase alloy sheet can be the same or different.

[0055] Exemplarily, the RE 1 -Fe-M 1 -B hard magnetic phase alloy sheet and the RE 2 -Fe-M 2 -B hard magnetic phase alloy sheet are prepared by a vacuum induction melting and rapid solidification spin casting furnace.

[0056] The PN-M 3 alloy sheet is prepared by weighing and proportioning raw materials, melting, rapid solidification, and cooling to form the alloy sheet; More specifically, weigh and proportion the raw materials according to the ratio, melt them under the protection of an inert gas, and at a certain casting temperature, pour the molten alloy liquid onto a rapidly rotating chill roll to prepare the alloy sheet after cooling; Furthermore, the inert gas is nitrogen or argon, preferably argon; the casting temperature is 600 - 1200 °C, preferably 650 - 1100 °C; the linear speed of the chill roll is 0.5 - 50 m / s, preferably 1 - 40 m / s; the average thickness of the alloy sheet is 50 - 800 μm; Exemplarily, the PN-M 3 alloy sheet is prepared by a vacuum induction melting and rapid solidification furnace; Or after being prepared into an ingot through batching, smelting, casting, and cooling, it is processed into an alloy sheet with a thickness ≤ 2 mm by machining; Preferably, the raw material is a pure metal or alloy containing PN, M 3 More preferably, the raw material is a pure metal containing PN, M 3 (2)The RE

[0057] -Fe-M 1 -B hard magnetic phase alloy sheets, RE 1 -B hard magnetic phase alloy sheets, and PN-M 2 -Fe-M 2 -B hard magnetic phase alloy sheets and PN-M 3 alloy sheets are respectively hydrogenated and crushed, ground by a jet mill to form alloy powders, and then mixed in proportion.

[0058] Specifically, the pressing and forming step includes magnetic field orientation pressing and forming; further, it also includes isostatic pressing and forming. According to experimental verification, the isostatic pressing and forming step has little influence on the magnet performance. Considering the cost comprehensively, preferably, the pressing and forming only undergoes magnetic field orientation pressing and forming to obtain a green compact.

[0059] Among them, the specific parameters of the magnetic field orientation pressing and forming are: the magnetic field strength is 1.0 - 6.0 T, preferably 2.0 - 5.0 T; the isostatic pressing and forming pressure is 120 - 270 MPa, preferably 150 - 240 MPa.

[0060] Specifically, the sintering and aging heat treatment includes: vacuum liquid phase sintering and aging treatment.

[0061] Among them, the sintering temperature of the vacuum liquid phase sintering is 900 - 1170 °C, preferably 925 - 1120 °C; the sintering time of the vacuum liquid phase sintering is 0.5 - 9 h, preferably 1 - 8.5 h.

[0062] Among them, the aging treatment includes primary aging treatment, and optionally includes or does not include secondary aging treatment. Preferably, the aging treatment includes secondary aging treatment.

[0063] The aging temperature of the primary aging treatment is 600 - 1000 °C, preferably 650 - 980 °C; the aging time is 0.5 - 8 h, preferably 0.5 - 7.5 h.

[0064] The aging temperature of the secondary aging treatment is 400 - 650 °C, preferably 410 - 640 °C; the aging time is 0.5 - 15 h, preferably 0.5 - 10 h.

[0065] After the vacuum liquid phase sintering and aging treatment are completed with heat preservation, they are cooled to room temperature by at least one of water cooling, air cooling, and air blast cooling.

[0066] Further, the preparation method further includes a grain boundary diffusion treatment step. After the surface of the sintered high-abundance rare earth Ce magnet after sintering aging heat treatment is ground and activated, a diffusion source containing heavy rare earth elements is attached. After diffusion heat treatment, a grain boundary diffusion sintered high-abundance Ce magnet is obtained.

[0067] Preferably, the diffusion treatment includes applying a diffusion source material on the surface of the magnet, and performing vacuum heating diffusion heat treatment, diffusion cooling, and diffusion aging treatment. By using the said diffusion treatment method, the diffusion efficiency during the grain boundary diffusion of the sintered magnet can be improved, thereby further improving the magnet performance.

[0068] Specifically, one or more of pure metals, alloys, and compounds containing heavy rare earth elements (Dy, Tb) can be attached to the surface of the high-abundance neodymium-iron-boron permanent magnet by means such as spraying, sputtering, and evaporation. Exemplarily, at least one of an alloy composed of Dy and / or Tb and optionally containing at least one of Al, Co, Cu, and Ga, pure metals of Dy and / or Tb, hydrides of Dy and / or Tb, oxides of Dy and / or Tb, fluorides of Dy and / or Tb, etc.; for example, dysprosium fluoride.

[0069] Specifically, the diffusion treatment can be carried out in a vacuum heat treatment furnace.

[0070] Preferably, the temperature of the vacuum heating diffusion treatment is 750 - 1000 °C, and the time of the vacuum heating diffusion treatment is 2 - 40 h.

[0071] Preferably, the temperature of the diffusion cooling is below 100 °C.

[0072] Preferably, the temperature of the diffusion aging treatment is 400 - 650 °C, such as 400, 450, 500, 550, 600, 650 °C, and the time of the diffusion aging treatment is 2 - 15 h, such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 h.

[0073] Preferably, before the diffusion treatment after the sintering process, the magnet can also be processed into the target finished product size.

[0074] Specifically, the above-mentioned sintered high-abundance Ce magnet can be used in the manufacture of magnetic components in fields such as rare earth permanent magnet motors, intelligent consumer electronic products, and medical devices.

[0075] Unless otherwise specified, the raw materials and reagents used in the following examples are all commercially available products, or can be prepared by known methods.

[0076] In the following embodiments of the present invention, PrNd is added in the form of an alloy, and the remaining metals are added in the form of simple substances. B is provided by a B-Fe alloy.

[0077] Example 1 (1) According to the designed composition ratio: PrNd: 30.5 wt.%, Co: 0.5 wt.%, Ga: 0.1 wt.%, Al: 0.1 wt.%, Cu: 0.1 wt.%, Zr: 0.1 wt.%, B: 0.95 wt.%, with the balance being Fe, weigh RE 1 -Fe-M 1 -B hard magnetic phase alloy raw materials, and carry out melting in a vacuum induction melting furnace under the protection of an Ar gas atmosphere. Pour the molten steel liquid onto a water-cooled copper roller with a rotation speed of 32 rpm. The pouring temperature of the steel liquid is 1380 °C to obtain RE 1 -Fe-M 1 -B hard magnetic phase alloy sheets; (2) According to the designed composition ratio PrNd: 6.10 wt.%, Ce: 24.40 wt.%, Co: 0.5 wt.%, Ga: 0.1 wt.%, Al: 0.1 wt.%, Cu: 0.1 wt.%, Zr: 0.1 wt.%, B: 0.95 wt.%, with the balance being Fe, weigh RE 2 -Fe-M 2 -B hard magnetic phase alloy raw materials, and carry out melting in a vacuum induction melting furnace under the protection of an Ar gas atmosphere. Pour the molten liquid onto a water-cooled copper roller with a rotation speed of 36 rpm. The pouring temperature of the liquid is 1320 °C to obtain RE 2 -Fe-M 2 -B hard magnetic phase alloy sheets; (3) According to the designed composition ratio PrNd: 75 wt.%, Cu: 10 wt.%, Ga: 15 wt.%, weigh PN-M 3 alloy raw materials, and carry out melting in a vacuum induction melting furnace under the protection of an Ar gas atmosphere. Pour the molten liquid onto a water-cooled copper roller with a rotation speed of 30 rpm. The pouring temperature of the liquid is 1100 °C to obtain PN-M 3 alloy sheets; (4) Subject the RE 1 -Fe-M 1 -B, RE 2 -Fe-M 2 -B hard magnetic phase alloys and PN-M 3 alloy sheets to hydrogen crushing, dehydrogenation, and jet milling respectively to obtain alloy powders with an average particle size of 2.8 μm, 3.5 μm, and 2.0 μm. Weigh 37.5 wt.% of RE 1-Fe-M 1 -B hard magnetic phase alloy powder and 62.5 wt.% of RE 2 -Fe-M 2 -B hard magnetic phase alloy powder are mixed in proportion; according to PN-M 3 alloy and RE 1 -Fe-M 1 -B hard magnetic phase alloy, RE 2 -Fe-M 2 The mixing mass percentage of the powder between -B hard magnetic phase alloy is 1.5:98.5 to weigh PN-M 3 alloy powder. In N 2 Under the protection of gas atmosphere, mix, add 0.1 wt% of antioxidant lubricant (conventional antioxidant lubricant known in the art), and stir and mix evenly; (5) Under the protection of N 2 gas atmosphere, fill the mixed powder into the mold cavity of the molding equipment mold, and perform orientation molding pressing with an orientation magnetic field strength of 2.5 T. Subsequently, perform isostatic pressing treatment at a pressure of 175 MPa in a cold isostatic press to obtain a green compact with a density of 4.5 g / cm 3 (calculated by weighing and dimension measurement of the green compact); (6) Under the protection of N 2 gas atmosphere, send the green compact into a vacuum sintering furnace, sinter at 1015°C for 3 h, and the sintering vacuum degree is below 1×10 -2 Pa. After the heat preservation is completed, fill with Ar gas and cool to below 65°C and then take out of the furnace to obtain a sintered blank with a density of 7.58 g / cm 3 .

[0078] Example 2 Example 2 is different from Example 1 only in that: in step (4), according to PN-M 3 alloy and RE 1 -Fe-M 1 -B hard magnetic phase alloy, RE 2 -Fe-M 2 The mixing mass percentage of the powder between -B hard magnetic phase alloy is 1.0:99.0 to weigh PN-M 3 alloy powder.

[0079] Example 3 Example 3 is different from Example 1 only in that: in step (4), RE 1 -Fe-M 1 -B, RE 2 -Fe-M 2 -B hard magnetic phase alloy and PN-M 3The alloy sheets are respectively made into alloy powders with average particle sizes of 3.2 μm, 4.0 μm and 2.2 μm through hydrogen crushing, dehydrogenation and jet milling.

[0080] Example 4 Compared with Example 1, Example 4 is only different in that: in step (3), according to the component design ratio PrNd: 75 wt.%, Cu: 10 wt.%, Ga: 15 wt.%, PN-M 3 alloy raw materials are weighed, melted in a vacuum induction melting furnace under the protection of an Ar gas atmosphere, and the molten liquid is made into PN-M alloy powder with an average particle size of 1.0 μm by gas atomization method. 3 (The PN-M alloy powder in this example 3 is directly purchased and can be customized from relevant manufacturers according to needs).

[0081] In step (4), 25 wt.% of RE 1 -Fe-M 1 -B hard magnetic phase alloy powder and 75 wt.% of RE 2 -Fe-M 2 -B hard magnetic phase alloy powder are mixed in proportion; according to the mixing mass percentage of the powder between PN-M alloy and RE 3 -Fe-M 1 -B hard magnetic phase alloy, RE 1 -B hard magnetic phase alloy is 1.0:99, PN-M 2 -Fe-M 2 -B hard magnetic phase alloy powder is weighed. 3 Alloy powder.

[0082] Example 5 Compared with Example 1, Example 5 is only different in that: in step (3), according to the component design ratio PrNd: 100 wt.%, PN-M 3 alloy raw materials are weighed.

[0083] Example 6 Compared with Example 1, Example 6 is only different in that: in step (4), according to the mixing mass percentage of the powder between PN-M alloy and RE 3 -Fe-M 1 -B hard magnetic phase alloy, RE 1 -B hard magnetic phase alloy is 3:97, PN-M 2 -Fe-M 2 -B hard magnetic phase alloy powder is weighed. 3 Alloy powder.

[0084] Comparative Example 1 Compared with Example 1, Comparative Example 1 is only different in that: in step (4), RE 1-Fe-M 1 -B, RE 2 -Fe-M 2 -B hard magnetic phase alloy and PN-M 3 The alloy flakes were respectively hydrogenated, dehydrogenated, and attrited to form alloy powders with an average particle size of 4 μm, 4 μm, and 4 μm.

[0085] Comparative Example 2 Comparative Example 2 is different from Example 1 only in that: in step (4), RE 1 -Fe-M 1 -B, RE 2 -Fe-M 2 -B hard magnetic phase alloy and PN-M 3 The alloy flakes were respectively hydrogenated, dehydrogenated, and attrited to form alloy powders with an average particle size of 2.8 μm, 3.5 μm, and 3.4 μm.

[0086] Comparative Example 3 Comparative Example 3 is different from Example 1 only in that: in step (4), PN-M 3 alloy powder is not added.

[0087] Comparative Example 4 Comparative Example 4 is different from Comparative Example 1 only in that: in step (3), according to the composition design ratio of Cu: 50 wt.%, Ga: 50 wt.% (i.e., without PN), PN-M 3 alloy raw materials were weighed.

[0088] The magnetic properties of the magnets prepared in Examples 1-6 and Comparative Examples 1-4 were respectively tested by a hysteresis loop measuring instrument, and the results are shown in Table 1.

[0089]

[0090] Comparing Example 1 and Example 2, it can be seen that due to the decrease in the addition amount of the PN alloy, although it can reduce the proportion of non-magnetic grain boundary phases in the magnet and improve the remanence and magnetic energy product of the magnet to some extent, it also inhibits the continuous distribution of the RE-rich phase in the magnet to a certain extent, resulting in a decrease in the coercivity of the magnet by about 16%.

[0091] Comparing Example 1 and Example 3, it can be seen that when the particle size ratio between the powders remains unchanged, due to RE 2 the increase in the average particle size of the powder particles causes the average grain size in the sintered magnet to increase accordingly, the number of grain boundaries decreases, and the magnetic properties of the magnet all decrease.

[0092] Due to Ce 2 Fe 14 the intrinsic magnetic properties of the B phase are lower than those of Nd 2 Fe 14For the B phase, when the Ce / RE content is increased to 60%, the remanence, maximum energy product and coercivity of the magnet will be significantly lower than those of the magnet with Ce / RE = 50%. However, the coercivity of the Ce / RE = 60% magnet prepared by the present invention can reach the level of the Ce / RE = 50% magnet, as can be seen from the comparison between Example 4 and Comparative Example 3.

[0093] As can be seen from the comparison between Example 1 and Example 5, due to the appropriate addition of metal element M in the PN alloy 3 the melting point of the grain boundary phase can be effectively reduced, the fluidity can be improved, which is beneficial to the further formation of a continuously distributed grain boundary phase, thereby reducing the proportion of massive non-magnetic rare-earth-rich phases. The prepared magnet can have relatively high remanence and coercivity. As can be seen from the comparison with Comparative Example 4, since the PN metal elements added in the PN alloy can be enriched in the surface layer of the main-phase grains through the grain boundaries, the intrinsic magnetic properties of the main phase in the surface layer region of the grains, such as the magnetocrystalline anisotropy field and the saturation magnetic polarization intensity, can be improved, and the nucleation of the demagnetizing field can be inhibited, so that relatively high magnetic properties can be obtained, with the remanence increased by 0.24 kGs and the coercivity increased by 32%.

[0094] As can be seen from the comparison between Example 1 and Comparative Example 1 and Comparative Example 3, for the magnet prepared by regulating the particle size of the alloy powder particles by the method of the present invention, since the rare-earth-rich phase can be distributed more continuously along the grain boundaries, the magnetocrystalline anisotropy field in the surface layer region of the main-phase grains is improved, and the grain sizes are relatively consistent after sintering, it has excellent magnetic properties.

[0095] As can be seen from the comparison between Example 1 and Comparative Example 2, since the particle size of the PN alloy powder is higher than that of the RE 2 main-phase alloy, the proportion of massive non-magnetic grain boundary phases in the magnet increases, resulting in a significant reduction in magnetic properties.

[0096] As can be seen from Example 6, when the addition amount of the PN alloy is too high, due to the sharp increase in the proportion of non-magnetic phases in the magnet, the remanence will be significantly reduced, and it is difficult for the magnet to obtain good magnetic properties. Therefore, the preferred range of the addition amount of the PN alloy in the present invention is 0.5 - 2 wt.%, and too high or too low will lead to a decrease in magnetic properties.

[0097] In summary, for the high-abundance Ce sintered magnet prepared by the present invention (taking the total amount of Ce / RE = 50 wt.% as an example), Br ≥ 12.47 kGs, Hcj ≥ 6.68 kOe, BH max ≥ 35.01 MGOe, having relatively good magnetic properties.

[0098] The above is only the preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A sintered high-abundance rare earth Ce magnet, characterized in that: The sintered high-abundance rare earth Ce magnet is prepared by mixing and sintering RE1-Fe-M1-B hard magnetic phase alloy powder, RE2-Fe-M2-B hard magnetic phase alloy powder and PN alloy powder; The particle size ratio of the RE1-Fe-M1-B hard magnetic phase alloy powder to the RE2-Fe-M2-B hard magnetic phase alloy powder is 0.1 to 0.9; The particle size ratio of the PN alloy powder to the RE1-Fe-M1-B hard magnetic phase alloy powder is 0.1 to 1; Wherein, RE1 is neodymium; or RE1 contains neodymium and at least one of praseodymium, gadolinium, terbium, dysprosium and holmium; RE2 is cerium; or RE2 contains cerium and at least one of lanthanum, praseodymium, neodymium, gadolinium, terbium, dysprosium, and holmium; PN includes at least one of praseodymium and neodymium; Among them, the ratio of cerium to the total mass of rare earth elements is: Ce / (RE1+RE2+PN)=0.18~0.87; M1 includes cobalt, copper, gallium; or M1 includes cobalt, copper, gallium and at least one of aluminum, titanium, and zirconium; M2 includes cobalt, copper, and gallium; or M2 includes cobalt, copper, gallium, and at least one of aluminum, titanium, and zirconium.

2. The magnet according to claim 1, characterized in that The particle size ratio of the RE1-Fe-M1-B hard magnetic phase alloy powder and the RE2-Fe-M2-B hard magnetic phase alloy powder is 0.2 to 0.8; The particle size ratio of the PN alloy powder to the RE1-Fe-M1-B hard magnetic phase alloy powder is 0.2-0.

8.

3. The magnet according to claim 1, characterized in that The mass ratio of the RE1-Fe-M1-B hard magnetic phase alloy powder to the RE2-Fe-M2-B hard magnetic phase alloy powder is 1-9:1-9; The PN alloy powder accounts for 0.1-5% of the total mass of the RE1-Fe-M1-B hard magnetic phase alloy powder, the RE2-Fe-M2-B hard magnetic phase alloy powder and the PN alloy powder.

4. The magnet according to claim 1, characterized in that The mass ratio of the RE1-Fe-M1-B hard magnetic phase alloy powder to the RE2-Fe-M2-B hard magnetic phase alloy powder is 2-4.5:5.5-8; The PN alloy powder accounts for 0.5-2% of the total mass of the RE1-Fe-M1-B hard magnetic phase alloy powder, the RE2-Fe-M2-B hard magnetic phase alloy powder and the PN alloy powder.

5. The magnet according to claim 1, characterized in that The PN alloy is a PN-M3 alloy, wherein M3 is at least one of cobalt, copper and gallium; and the proportion of PN is 60-100 wt.%, and the proportion of M3 is 0-40 wt.%.

6. The magnet according to claim 1, characterized in that: The specific composition of the RE1-Fe-M1-B hard magnetic phase alloy is: RE1: 25-35wt.%, Al: 0.0-1.5wt.%, Ti: 0.0-1.5wt.%, Co: 0.1-1.1wt.%, Cu: 0.1-1.1wt.%, Ga: 0.1-1.1wt.%, Zr: 0.0-1.5wt.%, B: 0.9-1.5wt.%, and the remainder is transition metal Fe element and impurity elements; The specific composition of the RE2-Fe-M2-B hard magnetic phase alloy is: RE2: 25-35 wt.%, Al: 0.0-1.5 wt.%, Ti: 0.0-1.5 wt.%, Co: 0.1-1.1 wt.%, Cu: 0.1-1.1 wt.%, Ga: 0.1-1.1 wt.%, Zr: 0.0-1.5 wt.%, B: 0.9-1.5 wt.%, and the remainder is transition metal Fe element and impurity elements; Among them, the La<0.15wt.% and Ce<0.15wt.% inaccurately measured elements in the two types of hard magnetic alloys are regarded as impurity elements.

7. The magnet according to claim 1, characterized in that The specific composition of the magnet is calculated by mass percentage: RE1+RE2+PN: 25~38wt.%; Al: 0.0~1.5wt.%, Ti: 0.0~1.5wt.%, Co: 0.1~6.75wt.%, Cu: 0.1~3.05wt.%, Ga: 0.1~3.05wt.%, Zr: 0.0~1.5wt.%, B: 0.9~1.5wt.%, and the remainder is transition metal Fe element and impurity elements.

8. The magnet according to claim 1, characterized in that The average particle size of the RE1-Fe-M1-B hard magnetic phase alloy powder, the RE2-Fe-M2-B hard magnetic phase alloy powder and the PN alloy powder is 0.5-6.5 μm.

9. A method for preparing a magnet according to any one of claims 1 to 8, characterized in that: First, RE1-Fe-M1-B hard magnetic phase alloy powder, RE2-Fe-M2-B hard magnetic phase alloy powder and PN alloy powder are prepared according to a preset formula and particle size ratio, and the average particle size of the powder is 0.5 to 6.5 μm; The three powders are mixed in proportion, pressed and molded, and sintered and subjected to aging heat treatment to finally obtain the sintered high-abundance rare earth Ce magnet.

10. Use of the magnet according to any one of claims 1 to 8 or the magnet prepared by the preparation method according to claim 9, characterized in that: The magnet is used in the manufacture of rare earth permanent magnet motors, smart consumer electronic products, and magnetic components in medical devices.

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