WO2021244312A1

WO2021244312A1 - Neodymium-iron-boron magnet material, raw material composition, and preparation method and application of neodymium-iron-boron magnet material

Info

Publication number: WO2021244312A1
Application number: PCT/CN2021/095076
Authority: WO
Inventors: 王金磊; 黄佳莹; 黎国妃; 汤志辉; 黄清芳
Original assignee: 厦门钨业股份有限公司; 福建省长汀金龙稀土有限公司
Priority date: 2020-06-01
Filing date: 2021-05-21
Publication date: 2021-12-09
Also published as: CN111613403B; CN111613403A

Abstract

A neodymium-iron-boron magnet material, a raw material composition, and a preparation method and application of the neodymium-iron-boron magnet material. The raw material composition of the neodymium-iron-boron magnet material comprises: a first component: LR comprising Nd, 0 to 10 mass percent but not equal to 0 of Ho, 0.12 to 0.45 mass percent of C, 0.12 to 0.6 mass percent of Cu, 0 to 0.42 mass percent but not equal to 0 of Ga, 0 to 0.5 mass percent of Co, 0 to 0.5 mass percent of Al, 0.05 to 0.45 mass percent of X, 0.9 to 1.05 mass percent of B, and the balance of Fe, wherein the first component does not comprise other heavy rare earth elements except Ho; and a second component: 0.2 to 1 mass percent of Dy and/or Tb. The neodymium-iron-boron magnet material is good in grain boundary continuity, high in residual magnetism, high in coercive force, good in high-temperature performance, and good in corrosion resistance.

Description

Neodymium iron boron magnet material, raw material composition and preparation method and application thereof

Technical field

The invention relates to a neodymium iron boron magnet material, a raw material composition, and a preparation method and application thereof.

Background technique

Nd-Fe-B permanent magnet material is based on Nd2Fel4B compound, which has the advantages of high magnetic performance, low thermal expansion coefficient, easy processing and low price. Since its introduction, it has grown at an average annual rate of 20-30% and has become the most widely used Of permanent magnet materials. According to the preparation method, Nd-Fe-B permanent magnets can be divided into three types: sintering, bonding and hot pressing. Among them, sintered magnets account for more than 80% of the total output and are the most widely used.

With the continuous optimization of the preparation process and magnet composition, the maximum magnetic energy product of sintered Nd-Fe-B magnets has approached the theoretical value. With the vigorous development of emerging industries such as wind power generation, hybrid electric vehicles and inverter air conditioners in recent years, the demand for high-performance Nd-Fe-B magnets has increased. The high temperature performance of the magnet puts forward higher requirements.

In the prior art, when making heat-resistant and corrosion-resistant sintered Nd-Fe-B magnets, Co is the most used and most effective element. This is because the addition of Co can reduce the reversible temperature coefficient of magnetic induction, effectively increase the Curie temperature, and can improve the corrosion resistance of the NdFeB magnet. However, the addition of Co easily causes the coercivity to decrease, and the cost of Co is higher. The Al element can reduce the infiltration angle between the main phase and the surrounding liquid phase during the sintering process, and improve the coercivity by improving the microstructure between the main phase and the Nd-rich phase. Therefore, in the prior art, the addition of Al is usually used to increase the coercivity. Compensate the decrease in coercivity caused by the addition of Co. However, excessive addition of Al will deteriorate the remanence and Curie temperature.

Summary of the invention

In order to overcome the prior art NdFeB magnets by adding Co to increase the Curie temperature and corrosion resistance, and Co easily causes a sharp drop in coercive force and expensive defects, and excessive addition of Al worsens the remanence and residence. The defect of internal temperature provides a neodymium iron boron magnet material, raw material composition, and preparation method and application thereof. The neodymium iron boron magnet material of the present invention has good grain boundary continuity, high remanence, high coercivity, good high temperature performance, and good corrosion resistance.

In order to achieve the above objectives, the present invention adopts the following technical solutions:

A raw material composition of neodymium iron boron magnet material, comprising a first component and a second component, the first component is an element added during smelting, and the second component is an element added during grain boundary diffusion element;

The first component includes:

Light rare earth element LR, said LR includes Nd;

Ho, 0～10mas%, and not 0;

C, 0.12～0.45mas%;

Cu, 0.12～0.6mas%;

Ga, 0～0.42mas%, and not 0;

Co, 0～0.5mas%;

Al, 0～0.5mas%;

X, 0.05～0.45mas%; said X includes one or more of Ti, Nb, Zr, Hf, V, Mo, W, Ta and Cr;

B, 0.9～1.05mas%;

The balance is Fe;

The first component does not include other heavy rare earth elements except Ho;

The second component includes: Dy and/or Tb, 0.2-1mas%;

mas% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material.

In the present invention, the total rare earth content in the raw material composition of the neodymium iron boron magnet material is generally 29.5-32.5mas%; for example, 30.3mas%, 30.4mas%, 30.5mas%, 30.6mas%, 30.7mas% or 31.5mas %.

In the present invention, the Nd content is preferably 14.5-28.6 mas%, such as 18.5 mas%, 19.2 mas%, 22.8 mas%, 23.5 mas%, 24 mas% or 25 mas%.

In the present invention, the LR may also include other conventional light rare earth elements in the art, such as Pr and/or Sm. Wherein, when the LR contains Pr, the content of Pr may be 0-16 mas%, and not 0 mas%; preferably 3-8 mas%, such as 4.8 mas% or 6.4 mas%. The added form of Pr may be pure Pr and/or PrNd, preferably PrNd. The PrNd is an alloy of Pr and Nd, and the mass ratio of Pr to Nd in PrNd is generally 25:75 or 20:80. When the LR contains Sm, the content of Sm may be 0-5 mas%, and not 0; for example, 4.5 mas%.

In the present invention, the Ho content is preferably 1-8mas%, such as 4mas%, 6mas%, 7mas% or 7.5mas%.

In the present invention, the content of C is preferably in the range of 0.13 to 0.32 mas%, such as 0.16 mas% or 0.25 mas%.

In the present invention, the Cu content is preferably in the range of 0.13 to 0.55 mas%, such as 0.2 mas%, 0.25 mas%, 0.36 mas% or 0.45 mas%.

In the present invention, the quality of the C and Cu is preferably 1: (0.8-1).

In the present invention, the Ga content range is preferably 0.02-0.35 mas%, such as 0.06 mas%, 0.15 mas%, 0.2 mas%, 0.25 mas% or 0.3 mas%.

In the present invention, the content of Co is preferably 0-0.2 mas%, such as 0.1 mas%.

In the present invention, the content of Al is preferably 0-0.3mas%, more preferably 0-0.1mas%, such as 0.01mas%, 0.02mas%, 0.04mas%, 0.05mas% or 0.07mas% . When the content of Al is 0-0.1 mas%, Al may be impurity Al introduced during the preparation of the neodymium iron boron magnet and/or additional Al added. When the content of Al is 0-0.04mas%, Al is generally the impurity Al introduced in the process of preparing the neodymium iron boron magnet material.

In the present invention, the content of X is preferably 0.2 to 0.41 mas%, for example, 0.25 mas%, 0.26 mas%, 0.35 mas% or 0.4 mas%.

In the present invention, the type of X is preferably one or more of Ti, Nb, Zr and Hf, more preferably Ti and Nb, or Nb and Zr, or Ti, Nb and Zr.

When the X includes Zr, the content of the Zr preferably ranges from 0.1 to 0.3 mas%, such as 0.2 mas%, 0.25 mas% or 0.28 mas%.

When the X includes Ti, the content of Ti preferably ranges from 0.1 to 0.3 mas%, for example, 0.15 mas% or 0.16 mas%.

When the X includes Nb, the content of Nb is preferably in the range of 0.05 to 0.3 mas%, such as 0.1 mas%, 0.2 mas% or 0.24 mas%.

When X includes Ti and Nb, the mass ratio of Ti and Nb can be conventional in the art, generally (0.01-100):1, preferably (0.1-10):1, such as 1:1, 5:4 , 2:3 or 3:2.

When X includes Nb and Zr, the mass ratio of Nb and Zr can be conventional in the art, generally 1: (0.01-100), preferably 1: (0.1-10), for example, 1: 2 or 1: 4.

When X includes Ti, Nb and Zr, the mass ratio of Ti, Nb and Zr can be conventional in the art, generally (0.01-100): 1: (0.01-100), preferably (0.1-10): 1: (0.1-10), for example, 1:1:2.

In the present invention, the X may also include Mn, and the content of Mn may range from 0 to 0.04 mas%, such as 0.01 mas% or 0.02 mas%.

In the present invention, the content of B is preferably in the range of 0.94 to 1.02 mas%, such as 0.96 mas%, 0.964 mas%, 0.97 mas% or 0.98 mas%.

In the present invention, the content of Dy and/or Tb in the second component preferably ranges from 0.5 to 0.8 mas%.

When the second component includes Dy, the content of Dy preferably ranges from 0.2 to 1 mas%, such as 0.5 mas% or 0.8 mas%. The addition form of Dy in the second component may be one or more of pure Dy, Dy alloy and Dy fluoride. Wherein, the Dy alloy is preferably DyGaCu; in the DyGaCu alloy, the Dy content is preferably ≥75mas%, more preferably ≥95mas%, and the above percentage is the percentage of Dy content in the total mass of the DyGaCu alloy.

When the second component includes Tb, the content of Tb preferably ranges from 0.2 to 1 mas%, such as 0.5 mas%. The addition form of Tb in the second component may be one or more of pure Tb, Tb alloy and Tb fluoride. The Tb alloy is preferably a TbGaCu alloy; in the TbGaCu alloy, the Tb content is preferably ≥75mas%, more preferably ≥95mas%, and the above percentage is the percentage of the amount of Tb in the total mass of the TbGaCu alloy.

When the second component includes a mixture of Dy and Tb, the mass ratio of Dy and Tb can be any value, generally 1: (0.01-100), preferably 1: (0.3-3), for example, 1. :1 or 3:2.

In a preferred embodiment of the present invention, the raw material composition of the neodymium iron boron magnet material includes: the first component: Nd, 25mas%; Ho, 6mas%; Cu, 0.55mas%; C, 0.16mas %; Ga, 0.25mas%; Al, 0.07mas%; Ti, 0.25mas%; Nb, 0.2mas%; B, 0.97mas%; the second component: Tb, 0.5mas%; the balance is Fe.

In a preferred embodiment of the present invention, the raw material composition of the neodymium iron boron magnet material includes: the first component: Nd, 28.6 mas%; Ho, 1 mas%; Cu, 0.2 mas%; C, 0.16 mas%; Ga, 0.2mas%; Zr, 0.25mas%; B, 0.96mas%; the second component: Dy, 1mas%; the balance is Fe.

In a preferred embodiment of the present invention, the raw material composition of the neodymium iron boron magnet material includes: the first component: PrNd, 25.6 mas%; Ho, 4 mas%; Cu, 0.13 mas%; C, 0.13 mas%; Ga, 0.06mas%; Ti, 0.16mas%; Nb, 0.24mas%; Mn, 0.01mas%; B, 0.98mas%; The second component: Dy, 0.8mas%; the balance is Fe .

In a preferred embodiment of the present invention, the raw material composition of the neodymium iron boron magnet material includes: the first component: Nd, 18.5 mas%; Sm, 4.5 mas%; Ho, 7.5 mas%; Cu, 0.45mas%; C, 0.13mas%; Ga, 0.2mas%; Al, 0.05mas%; Ti, 0.15mas%; Nb, 0.1mas%; B, 0.964mas%; The second component: Tb, 0.2 mas%; the balance is Fe.

In a preferred embodiment of the present invention, the raw material composition of the neodymium iron boron magnet material includes: the first component: Nd, 14.5 mas%; Pr, 4.8 mas%; Ho, 10 mas%; Cu, 0.25 mas%; C, 0.25mas%; Ga, 0.02mas%; Zr, 0.25mas%; B, 0.98mas%; the second component: Dy, 0.2mas%; the balance is Fe.

In a preferred embodiment of the present invention, the raw material composition of the neodymium iron boron magnet material includes: the first component: Nd, 23.5 mas%; Ho, 8 mas%; Cu, 0.45 mas%; C, 0.25 mas%; Ga, 0.42mas%; Co, 0.1mas%; Nb, 0.05mas%; Zr, 0.2mas%; Mn, 0.01mas%; B, 0.98mas%; The second component: Tb, 1mas% ; The balance is Fe.

In a preferred embodiment of the present invention, the raw material composition of the neodymium iron boron magnet material includes: the first component: Nd, 24mas%; Ho, 6mas%; Cu, 0.36mas%; C, 0.45mas %; Ga, 0.06mas%; Al, 0.04mas%; Ti, 0.1mas%; Nb, 0.1mas%; Zr, 0.2mas%; B, 0.97mas%; The second component: Tb, 0.5mas% ; The balance is Fe.

In a preferred embodiment of the present invention, the raw material composition of the neodymium iron boron magnet material includes: the first component: Nd, 22.8mas%; Ho, 7mas%; Cu, 0.6mas%; C, 0.45 mas%; Ga, 0.15mas%; Al, 0.02mas%; Co, 0.2mas%; Nb, 0.1mas%; Zr, 0.28mas%; Mn, 0.02mas%; B, 0.964mas%; the second group Points: Dy, 0.5mas%; the balance is Fe.

In the present invention, the raw material composition of the neodymium iron boron magnet material may contain inevitable impurities.

In the present invention, "the balance is Fe" does not exclude that the raw material composition of the neodymium iron boron magnet material also includes other elements in addition to the elements mentioned in the present invention. When the raw material composition of the neodymium iron boron magnet material also includes other elements in addition to the elements mentioned in the present invention, the amount of Fe is adjusted accordingly, so that the raw material composition of the neodymium iron boron magnet material The mass percentage content of elements other than Fe is within the range defined by the present invention.

The present invention also provides a preparation method of neodymium iron boron magnet material, which adopts the raw material composition of the neodymium iron boron magnet material as described above, and the preparation method includes the following steps:

S1. Melting, pulverizing, molding, and sintering the first component to obtain a neodymium iron boron sintered body;

S2, using the second component to perform grain boundary diffusion on the neodymium iron boron sintered body obtained in step S1;

S3. Heat treatment to obtain neodymium iron boron magnet material.

In the present invention, in step S1, the smelting operation and conditions can be a conventional smelting process in the field, generally, each element of the first component is smelted and casted by an ingot process or a quick-setting sheet process to obtain Alloy flakes.

In the present invention, in step S1, the smelting temperature may be 1300-1700°C, for example 1500°C.

In the present invention, in step S1, the melting equipment is generally a high frequency vacuum melting furnace and/or an intermediate frequency vacuum melting furnace. The intermediate frequency vacuum smelting furnace may be an intermediate frequency vacuum induction rapid solidification belt spinning furnace.

Those skilled in the art know that because rare earth elements are usually lost in the smelting and sintering process, in order to ensure the quality of the final product, an additional 0-0.3mas% rare earth element ( Generally Nd element), the percentage is the mass percentage of the content of the additional rare earth element to the total content of the raw material composition; in addition, the content of this part of the additional rare earth element is not included in the category of the raw material composition.

In the present invention, in step S1, the operation and conditions of the powder milling can be conventional milling processes in the art, and generally include hydrogen crushing powder milling and/or jet milling powder milling.

The hydrogen crushing and pulverizing generally includes hydrogen absorption, dehydrogenation and cooling treatment. The temperature of the hydrogen absorption is generally 20 to 200°C, preferably 20 to 40°C (ie, room temperature). The pressure of the hydrogen absorption is generally 50 to 600 kPa, such as 90 kPa. The temperature of the dehydrogenation is generally 400-650°C, such as 550°C.

The gas stream in the gas stream milling powder can be, for example, nitrogen gas and/or argon gas. The pressure of the air jet milling powder is generally 0.1-2 MPa, preferably 0.5-0.7 MPa, for example 0.65 MPa. The efficiency of the jet milling powder may vary according to different equipment, for example, it may be 30-400 kg/h, preferably 200 kg/h.

In the present invention, in step S1, the molding operation and conditions can be a conventional molding process in the field, such as a magnetic field molding method. The magnetic field strength of the magnetic field forming method is generally above 1.5T.

In the present invention, in step S1, the sintering operation and conditions can be a conventional sintering process in the art, such as a vacuum sintering process and/or an inert atmosphere sintering process. The vacuum sintering process or the inert atmosphere sintering process are conventional operations in the art. When an inert atmosphere sintering process is used, the initial stage of the sintering can be performed under the condition of a vacuum degree of less than 0.5 Pa. The inert atmosphere may be an atmosphere containing inert gas conventional in the art, such as helium or argon.

In the present invention, in step S1, the sintering temperature may be 1000-1200°C, preferably 1030-1090°C.

In the present invention, in step S1, the sintering time may be 0.5-10h, preferably 2-8h.

In the present invention, in step S2, the operation and conditions of the grain boundary diffusion can be a conventional grain boundary diffusion process in the art, and generally the second component is applied to the neodymium iron boron sintered body for heat preservation. . Wherein, the application method can be coating, magnetron plasma sputtering or evaporation.

The coating operation and conditions can be conventional in the art. Generally, the second component is coated on the neodymium iron boron sintered body in the form of a fluoride or a low melting point alloy. When the second component includes Tb, preferably, Tb is coated in the form of a fluoride or a low melting point alloy of Tb. When the second component contains Dy, preferably, Dy is coated in the form of Dy fluoride or a low melting point alloy.

The operation and conditions of the magnetron plasma sputtering can be conventional in the art. Generally, the target material of the second component is bombarded by an inert gas to generate Dy and/or Tb ions, which are uniformly attached to the target through the control of a magnetic field. The surface of the neodymium iron boron sintered body.

The operating conditions and the conventional art can be deposited, typically by a metal of the second component is made of a shaped evacuated to a set value (e.g., 5 × 10 5Pa to diffusion in a vacuum oven ^{- 2} Pa) and heating to a set temperature (such as 500-900° C.) to generate Dy and/or Tb vapor, thereby enriching the surface of the neodymium iron boron sintered body.

In the present invention, in step S2, the temperature of the grain boundary diffusion may be 800-1000°C, preferably 850-950°C, more preferably 900°C. The time for the grain boundary diffusion may be 12 to 90 hours, such as 24 hours.

In the present invention, in step S3, the temperature of the heat treatment may be 480°C to 510°C. The heat treatment time may be 2 to 4 hours.

The present invention also provides a neodymium iron boron magnet material, which is prepared by the above-mentioned preparation method of neodymium iron boron magnet material.

The present invention also provides a neodymium iron boron magnet material, which includes:

Light rare earth element LR, said LR includes Nd;

Ho, 0～10mas%, and not 0;

Dy and/or Tb, 0.2～1mas%;

C, 0.12～0.45mas%;

Cu, 0.12～0.6mas%;

Ga, 0～0.42mas%, and not 0;

Co, 0～0.5mas%;

Al, 0～0.5mas%;

B, 0.9～1.05mas%;

The balance is Fe;

mas% is the mass percentage of each element in the neodymium iron boron magnet material;

The microstructure of the neodymium iron boron magnet material includes a main phase, a grain boundary epitaxial layer and a neodymium rich phase; the main phase and the grain boundary epitaxial layer are distributed with Ho and C, and the main phase has no Dy or Tb distribution, The neodymium-rich phase is distributed with Cu and Dy and/or Tb, and the continuity of the grain boundary of the neodymium-iron-boron magnet material is above 96.5%.

In the present invention, more than 95% of the total mass of the Ho element is preferably distributed in the main phase and the grain boundary epitaxial layer. In other words, only a small part of the Ho element is distributed in the neodymium-rich phase.

In the present invention, more than 95% of the total mass of C element is preferably distributed in the main phase.

In the present invention, more than 70% of the total mass of Cu element is preferably distributed in the neodymium-rich phase.

In the present invention, the calculation method of the grain boundary continuity refers to the ratio of the length occupied by phases other than voids in the grain boundary (for example, the neodymium-rich phase, the same in the grain boundary epitaxial layer) to the total grain boundary length. The grain boundary continuity is preferably 96.7%-97.6%, such as 96.8%, 97.2% or 97.3%.

In the present invention, the total rare earth content in the neodymium iron boron magnet material is generally 29.5-32.5mas%; for example, 30.3mas%, 30.4mas%, 30.5mas%, 30.6mas%, 30.7mas% or 31.5mas%.

In the present invention, the LR may also include other conventional light rare earth elements in the art, such as Pr and/or Sm. Wherein, when the LR contains Pr, the content of Pr may be 0-16 mas%, and not 0 mas%; preferably 3-8 mas%, such as 4.8 mas% or 6.4 mas%. When the LR contains Sm, the content of Sm may be 0-5 mas%, and not 0; for example, 4.5 mas%.

In the present invention, the content of Dy and/or Tb is preferably 0.5-0.8 mas%.

When the neodymium iron boron magnet material includes Dy, the content of the Dy preferably ranges from 0.2 to 1 mas%, such as 0.5 mas% or 0.8 mas%.

When the neodymium iron boron magnet material includes Tb, the content of Tb preferably ranges from 0.2 to 1 mas%, such as 0.5 mas%.

When the neodymium iron boron magnet material includes a mixture of Dy and Tb, the mass ratio of Dy and Tb can be any value, generally 1: (0.01-100), preferably 1: (0.3-3), for example 1:1 or 3:2.

In the present invention, the quality of the C and Cu is preferably 1: (0.8-1).

When the X includes Nb, the content of Nb is preferably in the range of 0.05 to 0.3 mas%, for example, 0.1 mas%, 0.2 mas% or 0.24 mas%.

In a preferred embodiment of the present invention, the neodymium iron boron magnet material includes: Nd, 25mas%; Ho, 6mas%; Cu, 0.55mas%; C, 0.16mas%; Ga, 0.25mas%; Al, 0.07 mas%; Ti, 0.25mas%; Nb, 0.2mas%; B, 0.97mas%; Tb, 0.5mas%; the balance is Fe.

In a preferred embodiment of the present invention, the neodymium iron boron magnet material includes: Nd, 28.6mas%; Ho, 1mas%; Cu, 0.2mas%; C, 0.16mas%; Ga, 0.2mas%; Zr, 0.25mas%; B, 0.96mas%; Dy, 1mas%; the balance is Fe.

In a preferred embodiment of the present invention, the neodymium iron boron magnet material includes: Nd, 19.2mas%; Pr, 6.4mas%; Ho, 4mas%; Cu, 0.13mas%; C, 0.13mas%; Ga, 0.06mas%; Ti, 0.16mas%; Nb, 0.24mas%; Mn, 0.01mas%; B, 0.98mas%; Dy, 0.8mas%; the balance is Fe.

In a preferred embodiment of the present invention, the neodymium iron boron magnet material includes: Nd, 18.5mas%; Sm, 4.5mas%; Ho, 7.5mas%; Cu, 0.45mas%; C, 0.13mas%; Ga , 0.2mas%; Al, 0.05mas%; Ti, 0.15mas%; Nb, 0.1mas%; B, 0.964mas%; Tb, 0.2mas%; the balance is Fe.

In a preferred embodiment of the present invention, the neodymium iron boron magnet material includes: Nd, 14.5mas%; Pr, 4.8mas%; Ho, 10mas%; Cu, 0.25mas%; C, 0.25mas%; Ga, 0.02mas%; Zr, 0.25mas%; B, 0.98mas%; Dy, 0.2mas%; the balance is Fe.

In a preferred embodiment of the present invention, the neodymium iron boron magnet material includes: Nd, 23.5mas%; Ho, 8mas%; Cu, 0.45mas%; C, 0.25mas%; Ga, 0.42mas%; Co, 0.1mas%; Nb, 0.05mas%; Zr, 0.2mas%; Mn, 0.01mas%; B, 0.98mas%; Tb, 1mas%; the balance is Fe.

In a preferred embodiment of the present invention, the neodymium iron boron magnet material includes: Nd, 24mas%; Ho, 6mas%; Cu, 0.36mas%; C, 0.45mas%; Ga, 0.06mas%; Al, 0.04 mas%; Ti, 0.1mas%; Nb, 0.1mas%; Zr, 0.2mas%; B, 0.97mas%; Tb, 0.5mas%; the balance is Fe.

In a preferred embodiment of the present invention, the neodymium iron boron magnet material includes: Nd, 22.8mas%; Ho, 7mas%; Cu, 0.6mas%; C, 0.45mas%; Ga, 0.15mas%; Al, 0.02mas%; Co, 0.2mas%; Nb, 0.1mas%; Zr, 0.28mas%; Mn, 0.02mas%; B, 0.964mas%; Dy, 0.5mas%; the balance is Fe.

In the present invention, the neodymium iron boron magnet material may contain inevitable impurities.

In the present invention, "the balance is Fe" does not exclude that the neodymium iron boron magnet material also includes other elements in addition to the elements mentioned in the present invention. When the neodymium iron boron magnet material also includes other elements besides the elements mentioned in the present invention, the amount of Fe should be adjusted accordingly, so that the mass of the elements other than Fe in the neodymium iron boron magnet material is 100%. The component content is within the range defined by the present invention.

The present invention also provides a raw material composition of the neodymium iron boron sintered body, which includes:

Light rare earth element LR, said LR includes Nd;

Ho, 0～10mas%, and not 0;

C, 0.12～0.45mas%;

Cu, 0.12～0.6mas%;

Ga, 0～0.42mas%, and not 0;

Co, 0～0.5mas%;

Al, 0～0.5mas%;

B, 0.9～1.05mas%;

The raw material composition of the neodymium iron boron sintered body does not include other heavy rare earth elements except Ho;

The balance is Fe;

mas% is the mass percentage of each element in the raw material composition of the neodymium iron boron sintered body.

In the present invention, the total rare earth content in the raw material composition of the neodymium iron boron sintered body is generally 28.5-32.3mas%; for example, 29.3mas%, 29.6mas%, 29.8mas%, 30mas%, 30.5mas%, 31mas% or 31.5mas%.

In the present invention, the quality of the C and Cu is preferably 1: (0.8-1).

In the present invention, the content of Al is preferably 0-0.3mas%, more preferably 0-0.1mas%, such as 0.01mas%, 0.02mas%, 0.04mas%, 0.05mas% or 0.07mas% . Wherein, when the content of Al is 0-0.1 mas%, Al may be impurity Al introduced in the process of preparing the neodymium iron boron sintered body and/or additional Al added. When the content of Al is 0-0.04mas%, Al is generally the impurity Al introduced in the process of preparing the neodymium iron boron sintered body.

In a preferred embodiment of the present invention, the raw material composition of the neodymium iron boron sintered body includes: Nd, 25mas%; Ho, 6mas%; Cu, 0.55mas%; C, 0.16mas%; Ga, 0.25mas% ; Al, 0.07mas%; Ti, 0.25mas%; Nb, 0.2mas%; B, 0.97mas%; the balance is Fe.

In a preferred embodiment of the present invention, the raw material composition of the neodymium iron boron sintered body includes: Nd, 28.6mas%; Ho, 1mas%; Cu, 0.2mas%; C, 0.16mas%; Ga, 0.2mas %; Zr, 0.25mas%; B, 0.96mas%; the balance is Fe.

In a preferred embodiment of the present invention, the raw material composition of the neodymium iron boron sintered body includes: PrNd, 25.6 mas%; Ho, 4 mas%; Cu, 0.13 mas%; C, 0.13 mas%; Ga, 0.06 mas %; Ti, 0.16mas%; Nb, 0.24mas%; Mn, 0.01mas%; B, 0.98mas%; the balance is Fe.

In a preferred embodiment of the present invention, the raw material composition of the neodymium iron boron sintered body includes: Nd, 18.5 mas%; Sm, 4.5 mas%; Ho, 7.5 mas%; Cu, 0.45 mas%; C, 0.13 mas%; Ga, 0.2mas%; Al, 0.05mas%; Ti, 0.15mas%; Nb, 0.1mas%; B, 0.964mas%; the balance is Fe.

In a preferred embodiment of the present invention, the raw material composition of the neodymium iron boron sintered body includes: Nd, 14.5mas%; Pr, 4.8mas%; Ho, 10mas%; Cu, 0.25mas%; C, 0.25mas %; Ga, 0.02mas%; Zr, 0.25mas%; B, 0.98mas%; the balance is Fe.

In a preferred embodiment of the present invention, the raw material composition of the neodymium iron boron sintered body includes: Nd, 23.5mas%; Ho, 8mas%; Cu, 0.45mas%; C, 0.25mas%; Ga, 0.42mas %; Co, 0.1mas%; Nb, 0.05mas%; Zr, 0.2mas%; Mn, 0.01mas%; B, 0.98mas%; the balance is Fe.

In a preferred embodiment of the present invention, the raw material composition of the neodymium iron boron sintered body includes: Nd, 24mas%; Ho, 6mas%; Cu, 0.36mas%; C, 0.45mas%; Ga, 0.06mas% ; Al, 0.04mas%; Ti, 0.1mas%; Nb, 0.1mas%; Zr, 0.2mas%; B, 0.97mas%; the balance is Fe.

In a preferred embodiment of the present invention, the raw material composition of the neodymium iron boron sintered body includes: Nd, 22.8mas%; Ho, 7mas%; Cu, 0.6mas%; C, 0.45mas%; Ga, 0.15mas %; Al, 0.02mas%; Co, 0.2mas%; Nb, 0.1mas%; Zr, 0.28mas%; Mn, 0.02mas%; B, 0.964mas%; the balance is Fe.

In the present invention, the raw material composition of the neodymium iron boron sintered body may contain inevitable impurities.

In the present invention, "the balance is Fe" does not exclude that the raw material composition of the neodymium iron boron sintered body also includes other elements in addition to the elements mentioned in the present invention. When the raw material composition of the neodymium iron boron sintered body also includes other elements in addition to the elements mentioned in the present invention, the amount of Fe is adjusted accordingly so that the raw material composition of the neodymium iron boron sintered body The mass percentage content of elements other than Fe is within the range defined by the present invention.

The present invention also provides a method for preparing the neodymium iron boron sintered body, which includes smelting, powdering, molding, and sintering the raw material composition of the neodymium iron boron sintered body. Wherein, the processes of the smelting, the powder making, the forming and the sintering are the same as the above.

The present invention also provides a neodymium iron boron sintered body, which is prepared by the above-mentioned method for preparing the neodymium iron boron sintered body.

The present invention also provides a neodymium iron boron sintered body, which comprises:

Light rare earth element LR, said LR includes Nd;

Ho, 0～10mas%, and not 0;

C, 0.12～0.45mas%;

Cu, 0.12～0.6mas%;

Ga, 0～0.42mas%, and not 0;

Co, 0～0.5mas%;

Al, 0～0.5mas%;

B, 0.9～1.05mas%;

The NdFeB sintered body does not include other heavy rare earth elements except Ho;

The balance is Fe;

mas% is the mass percentage of each element in the neodymium iron boron sintered body;

The microstructure of the neodymium iron boron sintered body includes a main phase, a grain boundary epitaxial layer and a neodymium-rich phase; the main phase and the grain boundary epitaxial layer are distributed with Ho and C, and the neodymium-rich phase is distributed with Cu, so The continuity of the grain boundary of the neodymium iron boron sintered body is 96% or more.

Wherein, the definition and description of the main phase, the grain boundary epitaxial layer, the neodymium-rich phase and the grain boundary continuity are as described above.

In the present invention, the total rare earth content in the NdFeB sintered body is generally 28.5-32.3mas%; for example, 29.3mas%, 29.6mas%, 29.8mas%, 30mas%, 30.5mas%, 31mas% or 31.5mas%.

In the present invention, the quality of the C and Cu is preferably 1: (0.8-1).

When the X includes Ti, the content of Ti is preferably in the range of 0.1 to 0.3 mas%, for example, 0.15 mas% or 0.16 mas%.

In a preferred embodiment of the present invention, the neodymium iron boron sintered body includes: Nd, 25mas%; Ho, 6mas%; Cu, 0.55mas%; C, 0.16mas%; Ga, 0.25mas%; Al, 0.07 mas%; Ti, 0.25mas%; Nb, 0.2mas%; B, 0.97mas%; the balance is Fe.

In a preferred embodiment of the present invention, the neodymium iron boron sintered body includes: Nd, 28.6mas%; Ho, 1mas%; Cu, 0.2mas%; C, 0.16mas%; Ga, 0.2mas%; Zr, 0.25mas%; B, 0.96mas%; the balance is Fe.

In a preferred embodiment of the present invention, the neodymium iron boron sintered body includes: Nd, 19.2mas%; Pr, 6.4mas%; Ho, 4mas%; Cu, 0.13mas%; C, 0.13mas%; Ga, 0.06mas%; Ti, 0.16mas%; Nb, 0.24mas%; Mn, 0.01mas%; B, 0.98mas%; the balance is Fe.

In a preferred embodiment of the present invention, the neodymium iron boron sintered body includes: Nd, 18.5mas%; Sm, 4.5mas%; Ho, 7.5mas%; Cu, 0.45mas%; C, 0.13mas%; Ga , 0.2mas%; Al, 0.05mas%; Ti, 0.15mas%; Nb, 0.1mas%; B, 0.964mas%; the balance is Fe.

In a preferred embodiment of the present invention, the neodymium iron boron sintered body includes: Nd, 14.5mas%; Pr, 4.8mas%; Ho, 10mas%; Cu, 0.25mas%; C, 0.25mas%; Ga, 0.02mas%; Zr, 0.25mas%; B, 0.98mas%; the balance is Fe.

In a preferred embodiment of the present invention, the neodymium iron boron sintered body includes: Nd, 23.5mas%; Ho, 8mas%; Cu, 0.45mas%; C, 0.25mas%; Ga, 0.42mas%; Co, 0.1mas%; Nb, 0.05mas%; Zr, 0.2mas%; Mn, 0.01mas%; B, 0.98mas%; the balance is Fe.

In a preferred embodiment of the present invention, the neodymium iron boron sintered body includes: Nd, 24mas%; Ho, 6mas%; Cu, 0.36mas%; C, 0.45mas%; Ga, 0.06mas%; Al, 0.04 mas%; Ti, 0.1mas%; Nb, 0.1mas%; Zr, 0.2mas%; B, 0.97mas%; the balance is Fe.

In a preferred embodiment of the present invention, the neodymium iron boron sintered body includes: Nd, 22.8mas%; Ho, 7mas%; Cu, 0.6mas%; C, 0.45mas%; Ga, 0.15mas%; Al, 0.02mas%; Co, 0.2mas%; Nb, 0.1mas%; Zr, 0.28mas%; Mn, 0.02mas%; B, 0.964mas%; the balance is Fe.

In the present invention, the neodymium iron boron sintered body may contain inevitable impurities.

In the present invention, "the balance is Fe" does not exclude that the neodymium iron boron sintered body also includes other elements in addition to the elements mentioned in the present invention. When the NdFeB sintered body also includes other elements besides the elements mentioned in the present invention, the amount of Fe should be adjusted accordingly so that the quality of the elements other than Fe in the NdFeB sintered body is 100%. The component content is within the range defined by the present invention.

The invention also provides the application of the neodymium iron boron magnet material or the neodymium iron boron sintered body in the preparation of magnetic steel.

On the basis of conforming to common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain preferred embodiments of the present invention.

The reagents and raw materials used in the present invention are all commercially available.

The positive and progressive effects of the present invention are:

1. In the present invention, by adding appropriate amounts of C and Cu during smelting, and adding appropriate amounts of heavy rare earth elements Ho, when there is no or low Co and no or low Al, the remanence and coercivity of the material are adjusted to a specific range At the same time, improve the high temperature stability, specifically:

1) At normal temperature, the remanence Br of the neodymium iron boron magnet material of the present invention can be 11.73-13.9kGs, and the magnetic polarization coercivity Hcj is 26.1-33.4kOe; at high temperature (140°C), Br is 10.4-12.32kGs, Hcj is 11.8～17.2kOe.

2) At normal temperature, the Br of the neodymium iron boron sintered body of the present invention is 11.81-14 kGs, Hcj is 17.5-22.5 kOe; the increase of Hcj after diffusion is 7.1-11.9 kOe.

3) Based on the formulation components of the application, the elements are matched, and the high temperature resistance is good: the absolute value of the Br temperature coefficient α of the neodymium iron boron magnet material is 0.089～0.0965%, and the absolute value of the Hcj temperature coefficient β is 0.4%～0.48% , The magnetic loss of full open circuit is 0.03%～1.02%.

2. The neodymium iron boron magnet material of the present invention also has good corrosion resistance.

Description of the drawings

Fig. 1 is an SEM image of a neodymium iron boron sintered body in Example 1 of the present invention;

Among them, 1. Main phase, 2. Grain boundary epitaxial layer, 3. Neodymium-rich phase.

Fig. 2 is an EPMA chart of the neodymium iron boron magnet material prepared in Example 1 of the present invention.

detailed description

The present invention will be further explained in the following examples, but the present invention is not limited to the scope of the described examples. In the following examples, the experimental methods without specific conditions are selected according to conventional methods and conditions, or according to the product specification.

Preparation Examples

The neodymium iron boron magnet materials in Examples 1-19 and Comparative Examples 1-8 were prepared according to the following preparation process:

S1. The first component is smelted, powdered, formed, and sintered, as follows:

(1) Melting and casting: Put each element of the first component in Table 1 (that is, each element in Table 2) into an alumina crucible, and in a high-frequency vacuum melting furnace with a vacuum of 0.05 Pa and 1500°C Under the conditions of vacuum melting; transfer to the intermediate frequency vacuum induction quick-solidification belt spinning furnace, pass argon gas, cast, quench, and obtain alloy flakes.

(2) Hydrogen breaking powder: place the alloy flakes in a hydrogen breaking furnace, vacuum the hydrogen breaking furnace at room temperature, and then pass 99.9% hydrogen into the hydrogen breaking furnace to maintain the hydrogen pressure At 90kPa, the alloy flakes fully absorb hydrogen; then, the temperature is raised to 550°C while vacuuming, and the alloy flakes are fully dehydrogenated; then the alloy flakes are cooled to obtain powder.

(3) Jet milling powder: under the condition of a nitrogen atmosphere and a pressure of 0.65 MPa, the powder obtained by hydrogen crushing is pulverized by jet milling (the efficiency of jet milling powder can be different according to the equipment, for example, it can be: 200kg/h) to obtain fine powder.

(4) Magnetic field molding: the fine powder obtained by airflow milling is compressed and molded in a magnetic field strength above 1.5T to obtain a molded body.

(5) Inert atmosphere sintering: transfer the molded body to a sintering furnace, and sinter it at a temperature of 1030 to 1090°C for 2 to 8 hours under a helium atmosphere under the condition of a vacuum degree of less than 0.5 Pa to obtain neodymium iron boron Sintered body.

S2. Use the second component in Table 1 to perform grain boundary diffusion on the neodymium iron boron sintered body, which is specifically as follows:

The surface of the neodymium iron boron sintered body obtained in step S1 is purified, the second component is coated on the surface of the neodymium iron boron sintered body, and diffused at a temperature of 900° C. for 24 hours, and then cooled to room temperature.

S3. Heat treatment: heat treatment at a temperature of 480 to 510°C for 3 hours to obtain a neodymium iron boron magnet material.

Table 1 The formula and content of the raw material composition of the neodymium iron boron magnet material (mas%)

*The mass ratio of Pr to Nd in PrNd alloy is 25:75.

Table 2 The formula and content of the raw material composition of the neodymium iron boron sintered body (mas%)

*The mass ratio of Pr to Nd in PrNd alloy is 25:75.

Effect Example 1: Material composition measurement

Using a conventional method in the art, a high-frequency inductively coupled plasma emission spectrometer (ICP-OES) was used to compare the neodymium iron boron magnet material (after diffusion) and the neodymium iron boron sintered body (before diffusion) in the examples and comparative examples. The components were measured, and the measurement results are shown in Table 3 and Table 4, respectively.

Table 3 Composition and content of neodymium iron boron magnet materials (mas%)

Table 4 Composition and content of neodymium iron boron sintered body (mas%)

Effect Example 2: Microstructure measurement

1. SEM analysis

The SEM images of the neodymium iron boron sintered body and the neodymium iron boron magnet materials in Examples 1-8 and Comparative Examples 1-5 were measured using a SEM-EDS backscattering instrument (instrument model: Hitachi S-3400N). The SEM image of the neodymium iron boron sintered body prepared in Example 1 is shown in FIG. 1.

Figure 1 is an SEM image of the NdFeB sintered body prepared in Example 1. The NdFeB sintered body contains C (0.16mas%), Cu (0.55mas%) and does not contain Al and Co, and contains heavy rare earths. The element is Ho. It can be seen from Figure 1 that the NdFeB sintered body contains main phase 1 (dark gray area), grain boundary epitaxial layer 2 (light gray area) and neodymium-rich phase 3 (white area). The neodymium-rich phase is more evenly distributed in the main phase. Between the phase particles, and the neodymium-rich phase occupies a relatively large proportion. The neodymium-rich phase uniformly distributed along the grain boundary can reduce the ferromagnetism of the main phase boundary phase, which is more conducive to the magnetic isolation of the main phase and effectively prevents the expansion of the reverse magnetic domain on the main phase, and promotes the subsequent diffusion element Dy or/ And the diffusion of Tb enhances the coercivity of the product.

2. SEM-EDS analysis

On the basis of Fig. 1, through the EDS test in the SEM electron microscope, the element composition of the neodymium iron boron sintered body prepared in Example 1 within the sampling range was calculated, and the results are shown in Table 5.

table 5

Note: Taking sampling point 1 as an example, it belongs to the main phase. Within this sampling range, the Nd content is 24.67 mas%, the Ho content is 6.12 mas%, the Cu content is 0.36 mas%, and the C content is 0.18 mas%. In order to be within the sampling range, the mass of each element accounts for the mass percentage of the total mass of all elements.

It can be seen from Table 5 that the Ho element mainly enters the main phase, and Ho can improve the anisotropy field of the main phase to a certain extent, which can increase Hcj. Since the formation energy of HoFeB is lower than that of NdFeB, the excess Nd element after the addition of Ho element preferentially forms the grain boundary Nd-rich phase, increasing the proportion of neodymium-rich phase, and providing more diffusion channels for subsequent Dy or/and Tb diffusion. Ho element also has a certain distribution in the grain boundary epitaxial layer and the neodymium-rich phase.

The C element is mainly distributed in the main phase, which can accelerate _{the transformation reaction process of the main phase Nd 2} Fe ₁₄ B, making the boundary neodymium-rich phase more thin and uniform, which is beneficial to improve the coercivity of the product and make the material less susceptible to corrosion.

The Cu element is mainly distributed in the neodymium-rich phase. The addition of Cu avoids the formation of harmful Nd-rich carbides, but forms NdCu ₂ compounds, which are enriched in the grain boundary to reduce the temperature of the grain boundary phase, and have better wetting with the main phase It can improve the distribution of the neodymium-rich phase, reduce the impact on the magnetic properties of the product, improve the high temperature performance, and also increase the corrosion resistance of the material.

3. EPMA analysis

The EPMA spectrum of the neodymium iron boron magnet material prepared in Example 1 was measured with a micro-area X-ray spectrum analyzer (instrument model: EPMA-1720), as shown in Figure 2. Figure 2 shows the distribution of Tb in the NdFeB magnet material. It can be seen from Figure 2 that after the NdFeB sintered body of Example 1 is diffused by Tb, the Tb element does not enter the main phase, but is mainly concentrated in the rich neodymium In phase. After Tb diffuses, the grain boundary neodymium-rich phase is clearly clear, and the proportion of neodymium-rich phase and grain boundary epitaxial layer is increased. The replaced Nd is more distributed around the main phase, which increases the continuity of the grain boundary and hinders the main phase. Direct exchange coupling improves the coercivity significantly.

4. Grain boundary continuity

Grain boundary continuity refers to the ratio of the length occupied by phases (such as neodymium-rich phase, grain boundary epitaxial layer) in the grain boundary other than voids to the total grain boundary length. Grain boundary continuity exceeding 96% can be called continuous channel. Based on the SEM images of the neodymium iron boron magnet materials of the respective examples and comparative examples, the grain boundary continuity was calculated. The grain boundary continuity of the neodymium iron boron magnet materials in Examples 1 to 8 and Comparative Examples 1 to 5 are shown in Table 6. The grain boundary continuity of the neodymium iron boron magnet materials of Examples 1 to 8 is all above 96.5%, and the grain boundary continuity of the neodymium iron boron magnet materials of Comparative Examples 1 to 5 are all below 96%.

Table 6 Grain boundary continuity of neodymium iron boron magnet materials

Effect embodiment 3: Magnetic performance test

Using the PFM-14 magnetic performance measuring instrument of British Hirst Company, the magnetic performance test was performed on each sample in the embodiment and the comparative example (the test sample is a disc with diameter D10mm*thickness 1.8mm), and the test results are shown in Table 7.

Table 7 Magnetic performance test results

The data in Table 7 are explained as follows:

1. Br (kGs): Residual magnetism, that is, the magnetism that the permanent magnet material can maintain after the external magnetic field is removed after saturation magnetization.

2. Hcj (kOe): Magnetic polarization intensity coercive force, also known as intrinsic coercive force.

3. ΔHcj (kOe): refers to the increase in the coercive force of the magnetic polarization strength Hcj of the NdFeB magnet material after diffusion relative to the coercive force of the magnetic polarization strength of the NdFeB sintered body before diffusion at room temperature (20°C) value.

4. The absolute value of the Br temperature coefficient α (%): refers to the temperature coefficient calculated based on the remanence Br of the neodymium iron boron magnet material at room temperature (20°C) and high temperature (140°C). The calculation formula is:

5. The absolute value of Hcj temperature coefficient β (%): refers to the temperature coefficient calculated based on the magnetic polarization coercivity Hcj of the neodymium iron boron magnet material at room temperature (20°C) and high temperature (140°C). The calculation formula is:

6. Full open circuit magnetic loss (%): refers to the full open circuit magnetism calculated on the basis of the change of the magnetic flux of the neodymium iron boron magnet material before and after baking after the NdFeB magnet material is baked for a certain period of time (such as 120min) at high temperature (140℃) Loss, the calculation formula is:

Among them, the magnetic flux of the neodymium iron boron magnet material is measured at normal temperature (20°C), which is recorded as M1; then the neodymium iron boron magnet material is heated in an oven to the set temperature of 140°C, kept for 120 minutes, and then cooled to room temperature to measure the magnetic flux , Marked as M2.

Analysis of the magnetic performance test results in Table 7:

1) Comparative Example 1: Based on Example 7, the content of C was increased to make it excessive, and other conditions remained unchanged.

At room temperature, compared with Example 7, the Br and Hcj of the NdFeB sintered body and the NdFeB magnet material in Comparative Example 1 are slightly reduced, and the coercive force increase (ΔHcj) after diffusion is small (approximately 0.6 times of Example 7). At high temperature, compared with Example 7, the Hcj of the NdFeB magnet material in Comparative Example 1 is smaller, the absolute value of the Br temperature coefficient α and the absolute value of the Hcj temperature coefficient β are larger, and the full open circuit magnetic loss is larger (approximately 27 times of Example 7), the high temperature performance is poor.

2) Comparative Example 2: Based on Example 8, the content of Cu is increased to make it excessive, and other conditions remain unchanged.

At room temperature, compared to Example 8, the Br and Hcj of the NdFeB sintered body and NdFeB magnet material in Comparative Example 2 are slightly reduced, and the coercivity increase (ΔHcj) after diffusion is small (approximately 0.6 times of Example 8). At high temperature, compared to Example 8, the Hcj of the NdFeB magnet material in Comparative Example 2 is smaller, the absolute value of the Br temperature coefficient α and the absolute value of the Hcj temperature coefficient β are larger, and the full open circuit magnetic loss is larger (approximately 28 times of Example 8), the high temperature performance is poor.

3) Comparative Example 3: Based on Example 3, the content of Cu is reduced, and other conditions remain unchanged.

At room temperature, compared with Example 3, the Br and Hcj of the NdFeB sintered body and NdFeB magnet material in Comparative Example 2 are slightly reduced, and the coercive force increase (ΔHcj) after diffusion is small (approximately 0.67 times of Example 3). At high temperatures, compared to Example 3, the Hcj of the NdFeB magnet material in Comparative Example 2 is smaller, the absolute value of the Br temperature coefficient α and the absolute value of the Hcj temperature coefficient β are larger, and the full open circuit magnetic loss is larger (approximately 22 times of Example 3), the high temperature performance is poor.

4) Comparative Example 4: Based on Example 6, the content of Ga is increased to make it excessive, and other conditions remain unchanged.

At room temperature, compared with Example 6, the Br and Hcj of the NdFeB sintered body and NdFeB magnet material in Comparative Example 3 are slightly reduced, and the coercive force increase (ΔHcj) after diffusion is small (approximately 0.5 times of Example 6). At high temperature, compared with Example 6, the Hcj of the NdFeB magnet material in Comparative Example 3 is smaller, the absolute value of the Br temperature coefficient α and the absolute value of the Hcj temperature coefficient β are larger, and the full open circuit magnetic loss is larger (approximately 34 times of Example 6), the high temperature performance is poor.

5) Comparative Example 5: Based on Example 2, without the X element, other conditions remain unchanged.

At room temperature, compared with Example 6, the Br and Hcj of the NdFeB sintered body and NdFeB magnet material in Comparative Example 4 are slightly reduced, and the coercive force increase (ΔHcj) after diffusion is small (approximately 0.78 times of Example 3). At high temperature, compared with Example 6, the Hcj of the NdFeB magnet material in Comparative Example 4 is smaller, the absolute value of the Br temperature coefficient α and the absolute value of the Hcj temperature coefficient β are larger, and the full open circuit magnetic loss is larger (approximately 8 times of Example 4), the high temperature performance is poor.

Claims

A raw material composition of neodymium iron boron magnet material, comprising a first component and a second component, the first component is an element added during smelting, and the second component is an element added during grain boundary diffusion element;

The first component includes:

Light rare earth element LR, said LR includes Nd;

Ho, 0～10mas%, and not 0;

C, 0.12～0.45mas%;

Cu, 0.12～0.6mas%;

Ga, 0～0.42mas%, and not 0;

Co, 0～0.5mas%;

Al, 0～0.5mas%;

X, 0.05～0.45mas%; said X includes one or more of Ti, Nb, Zr, Hf, V, Mo, W, Ta and Cr;

B, 0.9～1.05mas%;

The balance is Fe;

The first component does not include other heavy rare earth elements except Ho;

The second component includes: Dy and/or Tb, 0.2-1mas%;

mas% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material.
The raw material composition of neodymium iron boron magnet material according to claim 1, characterized in that:

The total rare earth content in the raw material composition of the neodymium iron boron magnet material is 29.5-32.5mas%; for example, 30.3mas%, 30.4mas%, 30.5mas%, 30.6mas%, 30.7mas% or 31.5mas%;

And/or, the Nd content is 14.5-28.6 mas%, such as 18.5 mas%, 19.2 mas%, 22.8 mas%, 23.5 mas%, 24 mas% or 25 mas%;

And/or, the LR further includes Pr and/or Sm; wherein, when the LR includes Pr, the content of Pr is 0-16 mas%, and not 0 mas%; preferably 3-8 mas% , For example, 4.8mas% or 6.4mas%; the added form of Pr is Pr and/or PrNd, preferably PrNd; when the LR contains Sm, the content of Sm is 0-5mas%, and no Is 0; for example, 4.5mas%;

And/or, the Ho content is 1-8mas%, such as 4mas%, 6mas%, 7mas% or 7.5mas%;

And/or, the content of C ranges from 0.13 to 0.32 mas%, such as 0.16 mas% or 0.25 mas%;

And/or, the Cu content ranges from 0.13 to 0.55 mas%, such as 0.2 mas%, 0.25 mas%, 0.36 mas% or 0.45 mas%; the quality of the C and Cu is preferably 1: (0.8 to 1);

And/or, the Ga content ranges from 0.02 to 0.35 mas%, such as 0.06 mas%, 0.15 mas%, 0.2 mas%, 0.25 mas% or 0.3 mas%;

And/or, the content of Co is 0-0.2 mas%, for example, 0.1 mas%;

And/or, the Al content ranges from 0 to 0.3 mas%, more preferably 0 to 0.1 mas%, such as 0.01 mas%, 0.02 mas%, 0.04 mas%, 0.05 mas% or 0.07 mas%;

And/or, the content of X is 0.2-0.41 mas%, for example, 0.25 mas%, 0.26 mas%, 0.35 mas% or 0.4 mas%;

And/or, the type of X is one or more of Ti, Nb, Zr and Hf, preferably Ti and Nb, or Nb and Zr, or Ti, Nb and Zr;

When the X includes Zr, the content of the Zr preferably ranges from 0.1 to 0.3 mas%, such as 0.2 mas%, 0.25 mas% or 0.28 mas%;

When the X includes Ti, the content of Ti is preferably in the range of 0.1 to 0.3 mas%, such as 0.15 mas% or 0.16 mas%;

When the X includes Nb, the content of Nb is preferably in the range of 0.05 to 0.3 mas%, such as 0.1 mas%, 0.2 mas% or 0.24 mas%;

When X includes Ti and Nb, the mass ratio of Ti and Nb is (0.01-100):1, preferably (0.1-10):1, such as 1:1, 5:4, 2:3 or 3: 2;

When X includes Nb and Zr, the mass ratio of Nb and Zr is 1: (0.01-100), preferably 1: (0.1-10), for example, 1:2 or 1:4;

When X includes Ti, Nb and Zr, the mass ratio of Ti, Nb and Zr is (0.01-100):1:(0.01-100), preferably (0.1-10):1:(0.1-10) , Such as 1:1:2;

And/or, the X further includes Mn, and the content of Mn ranges from 0 to 0.04 mas%, such as 0.01 mas% or 0.02 mas%;

And/or, the content of B ranges from 0.94 to 1.02 mas%, such as 0.96 mas%, 0.964 mas%, 0.97 mas% or 0.98 mas%;

And/or, the content of Dy and/or Tb in the second component ranges from 0.5 to 0.8 mas%;

When the second component includes Dy, the content of Dy ranges from 0.2 to 1 mas%, such as 0.5 mas% or 0.8 mas%; the addition form of Dy in the second component is Dy, Dy alloy, and Dy One or more of fluorides; among them, the Dy alloy is preferably DyGaCu; in the DyGaCu alloy, the Dy content is preferably ≥75mas%, more preferably ≥95mas%, and the above percentage is the amount of Dy accounting for The percentage of the total mass of the DyGaCu alloy;

When the second component includes Tb, the content of Tb ranges from 0.2 to 1 mas%, such as 0.5 mas%; the addition form of Tb in the second component is Tb, Tb alloy and Tb fluoride One or more; the Tb alloy is preferably a TbGaCu alloy; in the TbGaCu alloy, the Tb content is preferably ≥75mas%, more preferably ≥95mas%, and the above percentage is that the amount of Tb accounts for the total TbGaCu alloy Percentage of mass

When the second component includes a mixture of Dy and Tb, the mass ratio of Dy and Tb is 1: (0.01-100), preferably 1: (0.3-3), for example, 1:1 or 3:2 ；

Preferably, the raw material composition of the neodymium iron boron magnet material includes: the first component: Nd, 25mas%; Ho, 6mas%; Cu, 0.55mas%; C, 0.16mas%; Ga, 0.25mas %; Al, 0.07mas%; Ti, 0.25mas%; Nb, 0.2mas%; B, 0.97mas%; The second component: Tb, 0.5mas%; the balance is Fe;

Preferably, the raw material composition of the neodymium iron boron magnet material includes: the first component: Nd, 28.6 mas%; Ho, 1 mas%; Cu, 0.2 mas%; C, 0.16 mas%; Ga, 0.2 mas%; Zr, 0.25mas%; B, 0.96mas%; the second component: Dy, 1mas%; the balance is Fe;

Preferably, the raw material composition of the neodymium iron boron magnet material includes: the first component: PrNd, 25.6 mas%; Ho, 4 mas%; Cu, 0.13 mas%; C, 0.13 mas%; Ga, 0.06 mas%; Ti, 0.16mas%; Nb, 0.24mas%; Mn, 0.01mas%; B, 0.98mas%; the second component: Dy, 0.8mas%; the balance is Fe;

Preferably, the raw material composition of the neodymium iron boron magnet material includes: the first component: Nd, 18.5 mas%; Sm, 4.5 mas%; Ho, 7.5 mas%; Cu, 0.45 mas%; C, 0.13mas%; Ga, 0.2mas%; Al, 0.05mas%; Ti, 0.15mas%; Nb, 0.1mas%; B, 0.964mas%; The second component: Tb, 0.2mas%; the balance is Fe;

Preferably, the raw material composition of the neodymium iron boron magnet material includes: the first component: Nd, 14.5 mas%; Pr, 4.8 mas%; Ho, 10 mas%; Cu, 0.25 mas%; C, 0.25 mas%; Ga, 0.02mas%; Zr, 0.25mas%; B, 0.98mas%; the second component: Dy, 0.2mas%; the balance is Fe;

Preferably, the raw material composition of the neodymium iron boron magnet material includes: the first component: Nd, 23.5 mas%; Ho, 8 mas%; Cu, 0.45 mas%; C, 0.25 mas%; Ga, 0.42 mas%; Co, 0.1mas%; Nb, 0.05mas%; Zr, 0.2mas%; Mn, 0.01mas%; B, 0.98mas%; the second component: Tb, 1mas%; the balance is Fe;

Preferably, the raw material composition of the neodymium iron boron magnet material includes: the first component: Nd, 24mas%; Ho, 6mas%; Cu, 0.36mas%; C, 0.45mas%; Ga, 0.06mas %; Al, 0.04mas%; Ti, 0.1mas%; Nb, 0.1mas%; Zr, 0.2mas%; B, 0.97mas%; the second component: Tb, 0.5mas%; the balance is Fe;

Preferably, the raw material composition of the neodymium iron boron magnet material includes: the first component: Nd, 22.8 mas%; Ho, 7 mas%; Cu, 0.6 mas%; C, 0.45 mas%; Ga, 0.15 mas%; Al, 0.02mas%; Co, 0.2mas%; Nb, 0.1mas%; Zr, 0.28mas%; Mn, 0.02mas%; B, 0.964mas%; the second component: Dy, 0.5mas %; the balance is Fe.
A preparation method of neodymium iron boron magnet material, which adopts the raw material composition of the neodymium iron boron magnet material according to claim 1 or 2, and the preparation method comprises the following steps:

S1. Melting, pulverizing, molding, and sintering the first component to obtain a neodymium iron boron sintered body;

S2, using the second component to perform grain boundary diffusion on the neodymium iron boron sintered body obtained in step S1;

S3. Heat treatment to obtain neodymium iron boron magnet material;

In step S1, the smelting operation and conditions are preferably that each element of the first component is smelted and casted using an ingot process or a rapid-setting flake process to obtain alloy flakes;

In step S1, the smelting temperature is preferably 1300 to 1700°C, for example, 1500°C;

In step S1, the smelting equipment is preferably a high frequency vacuum melting furnace and/or an intermediate frequency vacuum melting furnace; the intermediate frequency vacuum melting furnace is preferably an intermediate frequency vacuum induction rapid solidification belt spinning furnace;

In step S1, the operation and conditions of the pulverizing preferably include hydrogen crushing pulverizing and/or jet milling pulverizing; wherein,

The hydrogen pulverization preferably includes hydrogen absorption, dehydrogenation and cooling; the temperature of the hydrogen absorption is preferably 20 to 200°C, more preferably 20 to 40°C; the pressure of the hydrogen absorption is relatively high. Preferably it is 50-600kPa, such as 90kPa; the temperature of the dehydrogenation is preferably 400-650°C, such as 550°C;

The gas flow in the air-flow milling powder is preferably nitrogen and/or argon; the pressure of the air-flow milling powder is preferably 0.1-2 MPa, more preferably 0.5-0.7 MPa, such as 0.65 MPa; The efficiency of the jet milling powder is preferably 30-400kg/h, such as 200kg/h;

In step S1, the molding operation and conditions are preferably a magnetic field molding method, and the magnetic field strength of the magnetic field molding method is preferably above 1.5T;

In step S1, the sintering operation and conditions are preferably a vacuum sintering process and/or an inert atmosphere sintering process;

In step S1, the sintering temperature is preferably 1000 to 1200°C, more preferably 1030 to 1090°C;

In step S1, the sintering time is preferably 0.5-10h, more preferably 2-8h;

In step S2, the operation and conditions of the grain boundary diffusion are preferably to apply the second component to the neodymium iron boron sintered body for heat preservation, wherein the application method is preferably coating , Magnetron plasma sputtering or evaporation; the temperature of the grain boundary diffusion is preferably 800-1000°C, more preferably 850-950°C, more preferably 900°C;

In step S2, the time for the grain boundary diffusion is preferably 12 to 90 hours, such as 24 hours;

In step S3, the temperature of the heat treatment is preferably 480°C to 510°C; the time of the heat treatment is preferably 2 to 4 hours.
A neodymium iron boron magnet material, which is prepared according to the method for preparing a neodymium iron boron magnet material according to claim 3.
A neodymium iron boron magnet material, which comprises:

Light rare earth element LR, said LR includes Nd;

Ho, 0～10mas%, and not 0;

Dy and/or Tb, 0.2～1mas%;

C, 0.12～0.45mas%;

Cu, 0.12～0.6mas%;

Ga, 0～0.42mas%, and not 0;

Co, 0～0.5mas%;

Al, 0～0.5mas%;

X, 0.05～0.45mas%; said X includes one or more of Ti, Nb, Zr, Hf, V, Mo, W, Ta and Cr;

B, 0.9～1.05mas%;

The balance is Fe;

mas% is the mass percentage of each element in the neodymium iron boron magnet material;

The microstructure of the neodymium iron boron magnet material includes a main phase, a grain boundary epitaxial layer and a neodymium-rich phase; the main phase and the grain boundary epitaxial layer are distributed with Ho and C, and the main phase has no Dy or Tb distribution, The neodymium-rich phase is distributed with Cu and Dy and/or Tb, and the continuity of the grain boundary of the neodymium-iron-boron magnet material is above 96.5%;

Preferably, the total rare earth content in the neodymium iron boron magnet material is 29.5-32.5mas%; for example, 30.3mas%, 30.4mas%, 30.5mas%, 30.6mas%, 30.7mas% or 31.5mas%;

Preferably, the Nd content is 14.5-28.6 mas%, such as 18.5 mas%, 19.2 mas%, 22.8 mas%, 23.5 mas%, 24 mas% or 25 mas%;

Optionally, the LR further includes Pr and/or Sm; wherein, when the LR includes Pr, the content of Pr is 0-16 mas% and not 0 mas%; preferably 3-8 mas% , For example, 4.8 mas% or 6.4 mas%; when the LR contains Sm, the content of Sm is 0-5 mas%, and is not 0; for example, 4.5 mas%;

Preferably, the Ho content is 1-8mas%, such as 4mas%, 6mas%, 7mas% or 7.5mas%;

Preferably, the content of Dy and/or Tb ranges from 0.5 to 0.8 mas%;

When the neodymium iron boron magnet material includes Dy, the content of Dy ranges from 0.2 to 1 mas%, such as 0.5 mas% or 0.8 mas%;

When the neodymium iron boron magnet material includes Tb, the content of Tb ranges from 0.2 to 1 mas%, such as 0.5 mas%;

When the neodymium iron boron magnet material includes a mixture of Dy and Tb, the mass ratio of Dy and Tb is 1: (0.01-100), preferably 1: (0.3-3), for example, 1:1 or 3: 2;

Preferably, the content of C ranges from 0.13 to 0.32 mas%, such as 0.16 mas% or 0.25 mas%;

Preferably, the Cu content ranges from 0.13 to 0.55 mas%, such as 0.2 mas%, 0.25 mas%, 0.36 mas% or 0.45 mas%; the quality of the C and Cu is preferably 1: (0.8 to 1);

Preferably, the Ga content ranges from 0.02 to 0.35 mas%, such as 0.06 mas%, 0.15 mas%, 0.2 mas%, 0.25 mas% or 0.3 mas%;

Preferably, the content of Co is 0-0.2mas%, such as 0.1mas%;

Preferably, the Al content ranges from 0 to 0.3 mas%, more preferably 0 to 0.1 mas%, such as 0.01 mas%, 0.02 mas%, 0.04 mas%, 0.05 mas% or 0.07 mas%;

Preferably, the content of X is 0.2-0.41 mas%, for example, 0.25 mas%, 0.26 mas%, 0.35 mas% or 0.4 mas%;

Preferably, the type of X is one or more of Ti, Nb, Zr and Hf, preferably Ti and Nb, or Nb and Zr, or Ti, Nb and Zr;

When the X includes Zr, the content of the Zr preferably ranges from 0.1 to 0.3 mas%, such as 0.2 mas%, 0.25 mas% or 0.28 mas%;

When the X includes Ti, the content of Ti is preferably in the range of 0.1 to 0.3 mas%, such as 0.15 mas% or 0.16 mas%;

When the X includes Nb, the content of Nb is preferably in the range of 0.05 to 0.3 mas%, such as 0.1 mas%, 0.2 mas% or 0.24 mas%;

When X includes Ti and Nb, the mass ratio of Ti and Nb is (0.01-100):1, preferably (0.1-10):1, such as 1:1, 5:4, 2:3 or 3: 2;

When X includes Nb and Zr, the mass ratio of Nb and Zr is 1: (0.01-100), preferably 1: (0.1-10), for example, 1:2 or 1:4;

When X includes Ti, Nb and Zr, the mass ratio of Ti, Nb and Zr is (0.01-100):1:(0.01-100), preferably (0.1-10):1:(0.1-10) , Such as 1:1:2;

Optionally, the X further includes Mn, and the content of the Mn ranges from 0 to 0.04 mas%, for example, 0.01 mas% or 0.02 mas%;

Preferably, the content of B ranges from 0.94 to 1.02 mas%, such as 0.96 mas%, 0.964 mas%, 0.97 mas% or 0.98 mas%;

Preferably, the neodymium iron boron magnet material includes: Nd, 25mas%; Ho, 6mas%; Cu, 0.55mas%; C, 0.16mas%; Ga, 0.25mas%; Al, 0.07mas%; Ti, 0.25 mas%; Nb, 0.2mas%; B, 0.97mas%; Tb, 0.5mas%; the balance is Fe;

Preferably, the neodymium iron boron magnet material includes: Nd, 28.6mas%; Ho, 1mas%; Cu, 0.2mas%; C, 0.16mas%; Ga, 0.2mas%; Zr, 0.25mas%; B, 0.96mas%; Dy, 1mas%; the balance is Fe;

Preferably, the neodymium iron boron magnet material includes: Nd, 19.2mas%; Pr, 6.4mas%; Ho, 4mas%; Cu, 0.13mas%; C, 0.13mas%; Ga, 0.06mas%; Ti, 0.16mas%; Nb, 0.24mas%; Mn, 0.01mas%; B, 0.98mas%; Dy, 0.8mas%; the balance is Fe;

Preferably, the neodymium iron boron magnet material includes: Nd, 18.5 mas%; Sm, 4.5 mas%; Ho, 7.5 mas%; Cu, 0.45 mas%; C, 0.13 mas%; Ga, 0.2 mas%; Al , 0.05mas%; Ti, 0.15mas%; Nb, 0.1mas%; B, 0.964mas%; Tb, 0.2mas%; the balance is Fe;

Preferably, the neodymium iron boron magnet material includes: Nd, 14.5mas%; Pr, 4.8mas%; Ho, 10mas%; Cu, 0.25mas%; C, 0.25mas%; Ga, 0.02mas%; Zr, 0.25mas%; B, 0.98mas%; Dy, 0.2mas%; the balance is Fe;

Preferably, the neodymium iron boron magnet material includes: Nd, 23.5mas%; Ho, 8mas%; Cu, 0.45mas%; C, 0.25mas%; Ga, 0.42mas%; Co, 0.1mas%; Nb, 0.05mas%; Zr, 0.2mas%; Mn, 0.01mas%; B, 0.98mas%; Tb, 1mas%; the balance is Fe;

Preferably, the neodymium iron boron magnet material includes: Nd, 24mas%; Ho, 6mas%; Cu, 0.36mas%; C, 0.45mas%; Ga, 0.06mas%; Al, 0.04mas%; Ti, 0.1 mas%; Nb, 0.1mas%; Zr, 0.2mas%; B, 0.97mas%; Tb, 0.5mas%; the balance is Fe;

Preferably, the neodymium iron boron magnet material includes: Nd, 22.8mas%; Ho, 7mas%; Cu, 0.6mas%; C, 0.45mas%; Ga, 0.15mas%; Al, 0.02mas%; Co, 0.2mas%; Nb, 0.1mas%; Zr, 0.28mas%; Mn, 0.02mas%; B, 0.964mas%; Dy, 0.5mas%; the balance is Fe.
A raw material composition of a neodymium iron boron sintered body, which comprises:

Light rare earth element LR, said LR includes Nd;

Ho, 0～10mas%, and not 0;

C, 0.12～0.45mas%;

Cu, 0.12～0.6mas%;

Ga, 0～0.42mas%, and not 0;

Co, 0～0.5mas%;

Al, 0～0.5mas%;

X, 0.05～0.45mas%; said X includes one or more of Ti, Nb, Zr, Hf, V, Mo, W, Ta and Cr;

B, 0.9～1.05mas%;

The raw material composition of the neodymium iron boron sintered body does not include other heavy rare earth elements except Ho;

The balance is Fe;

mas% is the mass percentage of each element in the raw material composition of the neodymium iron boron sintered body;

Preferably, the total rare earth content in the raw material composition of the neodymium iron boron sintered body is 28.5-32.3mas%; for example, 29.3mas%, 29.6mas%, 29.8mas%, 30mas%, 30.5mas%, 31mas% or 31.5% mas%;

Preferably, the Nd content is 14.5-28.6 mas%, such as 18.5 mas%, 19.2 mas%, 22.8 mas%, 23.5 mas%, 24 mas% or 25 mas%;

Optionally, the LR further includes Pr and/or Sm; wherein, when the LR includes Pr, the content of Pr is 0-16 mas%, and not 0 mas%; preferably 3-8 mas% , For example, 4.8mas% or 6.4mas%; the added form of Pr is Pr and/or PrNd, preferably PrNd; when the LR contains Sm, the content of Sm is 0-5mas%, and no Is 0; for example, 4.5mas%;

Preferably, the Ho content is 1-8mas%, such as 4mas%, 6mas%, 7mas% or 7.5mas%;

Preferably, the content of C ranges from 0.13 to 0.32 mas%, such as 0.16 mas% or 0.25 mas%;

Preferably, the Cu content ranges from 0.13 to 0.55 mas%, such as 0.2 mas%, 0.25 mas%, 0.36 mas% or 0.45 mas%; the quality of the C and Cu is preferably 1: (0.8 to 1);

Preferably, the Ga content ranges from 0.02 to 0.35 mas%, such as 0.06 mas%, 0.15 mas%, 0.2 mas%, 0.25 mas% or 0.3 mas%;

Preferably, the content of Co is 0-0.2mas%, such as 0.1mas%;

Preferably, the Al content ranges from 0 to 0.3 mas%, more preferably 0 to 0.1 mas%, such as 0.01 mas%, 0.02 mas%, 0.04 mas%, 0.05 mas% or 0.07 mas%;

Preferably, the content of X is 0.2-0.41 mas%, for example, 0.25 mas%, 0.26 mas%, 0.35 mas% or 0.4 mas%;

Preferably, the type of X is one or more of Ti, Nb, Zr and Hf, preferably Ti and Nb, or Nb and Zr, or Ti, Nb and Zr;

When the X includes Zr, the content of the Zr preferably ranges from 0.1 to 0.3 mas%, such as 0.2 mas%, 0.25 mas% or 0.28 mas%;

When the X includes Ti, the content of Ti is preferably in the range of 0.1 to 0.3 mas%, such as 0.15 mas% or 0.16 mas%;

When the X includes Nb, the content of Nb is preferably in the range of 0.05 to 0.3 mas%, such as 0.1 mas%, 0.2 mas% or 0.24 mas%;

When X includes Ti and Nb, the mass ratio of Ti and Nb is (0.01-100):1, preferably (0.1-10):1, such as 1:1, 5:4, 2:3 or 3: 2;

When X includes Nb and Zr, the mass ratio of Nb and Zr is 1: (0.01-100), preferably 1: (0.1-10), for example, 1:2 or 1:4;

When X includes Ti, Nb and Zr, the mass ratio of Ti, Nb and Zr is (0.01-100):1:(0.01-100), preferably (0.1-10):1:(0.1-10) , Such as 1:1:2;

Optionally, the X further includes Mn, and the content of the Mn ranges from 0 to 0.04 mas%, for example, 0.01 mas% or 0.02 mas%;

Preferably, the content of B ranges from 0.94 to 1.02 mas%, such as 0.96 mas%, 0.964 mas%, 0.97 mas% or 0.98 mas%;

Preferably, the raw material composition of the neodymium iron boron sintered body includes: Nd, 25mas%; Ho, 6mas%; Cu, 0.55mas%; C, 0.16mas%; Ga, 0.25mas%; Al, 0.07mas% ; Ti, 0.25mas%; Nb, 0.2mas%; B, 0.97mas%; the balance is Fe;

Preferably, the raw material composition of the neodymium iron boron sintered body includes: Nd, 28.6mas%; Ho, 1mas%; Cu, 0.2mas%; C, 0.16mas%; Ga, 0.2mas%; Zr, 0.25mas %; B, 0.96mas%; the balance is Fe;

Preferably, the raw material composition of the neodymium iron boron sintered body includes: PrNd, 25.6mas%; Ho, 4mas%; Cu, 0.13mas%; C, 0.13mas%; Ga, 0.06mas%; Ti, 0.16mas% %; Nb, 0.24mas%; Mn, 0.01mas%; B, 0.98mas%; the balance is Fe;

Preferably, the raw material composition of the neodymium iron boron sintered body includes: Nd, 18.5 mas%; Sm, 4.5 mas%; Ho, 7.5 mas%; Cu, 0.45 mas%; C, 0.13 mas%; Ga, 0.2 mas%; Al, 0.05mas%; Ti, 0.15mas%; Nb, 0.1mas%; B, 0.964mas%; the balance is Fe;

Preferably, the raw material composition of the neodymium iron boron sintered body includes: Nd, 14.5mas%; Pr, 4.8mas%; Ho, 10mas%; Cu, 0.25mas%; C, 0.25mas%; Ga, 0.02mas %; Zr, 0.25mas%; B, 0.98mas%; the balance is Fe;

Preferably, the raw material composition of the neodymium iron boron sintered body includes: Nd, 23.5mas%; Ho, 8mas%; Cu, 0.45mas%; C, 0.25mas%; Ga, 0.42mas%; Co, 0.1mas %; Nb, 0.05mas%; Zr, 0.2mas%; Mn, 0.01mas%; B, 0.98mas%; the balance is Fe;

Preferably, the raw material composition of the neodymium iron boron sintered body includes: Nd, 24mas%; Ho, 6mas%; Cu, 0.36mas%; C, 0.45mas%; Ga, 0.06mas%; Al, 0.04mas% ; Ti, 0.1mas%; Nb, 0.1mas%; Zr, 0.2mas%; B, 0.97mas%; the balance is Fe;

Preferably, the raw material composition of the neodymium iron boron sintered body includes: Nd, 22.8mas%; Ho, 7mas%; Cu, 0.6mas%; C, 0.45mas%; Ga, 0.15mas%; Al, 0.02mas %; Co, 0.2mas%; Nb, 0.1mas%; Zr, 0.28mas%; Mn, 0.02mas%; B, 0.964mas%; the balance is Fe.
A method for preparing a neodymium iron boron sintered body, comprising: smelting, powdering, molding, and sintering the raw material composition of the neodymium iron boron sintered body according to claim 6; the smelting, powdering, Molding and sintering are according to claim 3.
A neodymium iron boron sintered body, which is prepared according to the method for preparing a neodymium iron boron sintered body according to claim 7.
A neodymium iron boron sintered body, which comprises:

Light rare earth element LR, said LR includes Nd;

Ho, 0～10mas%, and not 0;

C, 0.12～0.45mas%;

Cu, 0.12～0.6mas%;

Ga, 0～0.42mas%, and not 0;

Co, 0～0.5mas%;

Al, 0～0.5mas%;

X, 0.05～0.45mas%; said X includes one or more of Ti, Nb, Zr, Hf, V, Mo, W, Ta and Cr;

B, 0.9～1.05mas%;

The NdFeB sintered body does not include other heavy rare earth elements except Ho;

The balance is Fe;

mas% is the mass percentage of each element in the neodymium iron boron sintered body;

The microstructure of the neodymium iron boron sintered body includes a main phase, a grain boundary epitaxial layer and a neodymium-rich phase; the main phase and the grain boundary epitaxial layer are distributed with Ho and C, and the neodymium-rich phase is distributed with Cu, so The grain boundary continuity of the neodymium iron boron sintered body is more than 96%;

Preferably, the total rare earth content in the NdFeB sintered body is 28.5-32.3mas%; for example, 29.3mas%, 29.6mas%, 29.8mas%, 30mas%, 30.5mas%, 31mas% or 31.5mas%;

Preferably, the Nd content is 14.5-28.6 mas%, such as 18.5 mas%, 19.2 mas%, 22.8 mas%, 23.5 mas%, 24 mas% or 25 mas%;

Optionally, the LR further includes Pr and/or Sm; wherein, when the LR includes Pr, the content of Pr is 0-16 mas%, and not 0 mas%; preferably 3-8 mas% , For example, 4.8 mas% or 6.4 mas%; when the LR contains Sm, the content of Sm is 0-5 mas%, and is not 0; for example, 4.5 mas%;

Preferably, the Ho content is 1-8mas%, such as 4mas%, 6mas%, 7mas% or 7.5mas%;

Preferably, the content of C ranges from 0.13 to 0.32 mas%, such as 0.16 mas% or 0.25 mas%;

Preferably, the Cu content ranges from 0.13 to 0.55 mas%, such as 0.2 mas%, 0.25 mas%, 0.36 mas% or 0.45 mas%; the quality of the C and Cu is preferably 1: (0.8 to 1);

Preferably, the Ga content ranges from 0.02 to 0.35 mas%, such as 0.06 mas%, 0.15 mas%, 0.2 mas%, 0.25 mas% or 0.3 mas%;

Preferably, the content of Co is 0-0.2mas%, such as 0.1mas%;

Preferably, the Al content ranges from 0 to 0.3 mas%, more preferably 0 to 0.1 mas%, such as 0.01 mas%, 0.02 mas%, 0.04 mas%, 0.05 mas% or 0.07 mas%;

Preferably, the content of X is 0.2-0.41 mas%, for example, 0.25 mas%, 0.26 mas%, 0.35 mas% or 0.4 mas%;

Preferably, the type of X is one or more of Ti, Nb, Zr and Hf, preferably Ti and Nb, or Nb and Zr, or Ti, Nb and Zr;

When the X includes Zr, the content of the Zr preferably ranges from 0.1 to 0.3 mas%, such as 0.2 mas%, 0.25 mas% or 0.28 mas%;

When the X includes Ti, the content of Ti is preferably in the range of 0.1 to 0.3 mas%, such as 0.15 mas% or 0.16 mas%;

When the X includes Nb, the content of Nb is preferably in the range of 0.05 to 0.3 mas%, such as 0.1 mas%, 0.2 mas% or 0.24 mas%;

When X includes Ti and Nb, the mass ratio of Ti and Nb is (0.01-100):1, preferably (0.1-10):1, such as 1:1, 5:4, 2:3 or 3: 2;

When X includes Nb and Zr, the mass ratio of Nb and Zr is 1: (0.01-100), preferably 1: (0.1-10), for example, 1:2 or 1:4;

When X includes Ti, Nb and Zr, the mass ratio of Ti, Nb and Zr is (0.01-100):1:(0.01-100), preferably (0.1-10):1:(0.1-10) , Such as 1:1:2;

Optionally, the X further includes Mn, and the content of the Mn ranges from 0 to 0.04 mas%, for example, 0.01 mas% or 0.02 mas%;

Preferably, the content of B ranges from 0.94 to 1.02 mas%, such as 0.96 mas%, 0.964 mas%, 0.97 mas% or 0.98 mas%;

Preferably, the neodymium iron boron sintered body comprises: Nd, 25mas%; Ho, 6mas%; Cu, 0.55mas%; C, 0.16mas%; Ga, 0.25mas%; Al, 0.07mas%; Ti, 0.25 mas%; Nb, 0.2mas%; B, 0.97mas%; the balance is Fe;

Preferably, the neodymium iron boron sintered body comprises: Nd, 28.6mas%; Ho, 1mas%; Cu, 0.2mas%; C, 0.16mas%; Ga, 0.2mas%; Zr, 0.25mas%; B, 0.96mas%; the balance is Fe;

Preferably, the neodymium iron boron sintered body comprises: Nd, 19.2mas%; Pr, 6.4mas%; Ho, 4mas%; Cu, 0.13mas%; C, 0.13mas%; Ga, 0.06mas%; Ti, 0.16mas%; Nb, 0.24mas%; Mn, 0.01mas%; B, 0.98mas%; the balance is Fe;

Preferably, the neodymium iron boron sintered body includes: Nd, 18.5mas%; Sm, 4.5mas%; Ho, 7.5mas%; Cu, 0.45mas%; C, 0.13mas%; Ga, 0.2mas%; Al , 0.05mas%; Ti, 0.15mas%; Nb, 0.1mas%; B, 0.964mas%; the balance is Fe;

Preferably, the neodymium iron boron sintered body includes: Nd, 14.5mas%; Pr, 4.8mas%; Ho, 10mas%; Cu, 0.25mas%; C, 0.25mas%; Ga, 0.02mas%; Zr, 0.25mas%; B, 0.98mas%; the balance is Fe;

Preferably, the neodymium iron boron sintered body comprises: Nd, 23.5mas%; Ho, 8mas%; Cu, 0.45mas%; C, 0.25mas%; Ga, 0.42mas%; Co, 0.1mas%; Nb, 0.05mas%; Zr, 0.2mas%; Mn, 0.01mas%; B, 0.98mas%; the balance is Fe;

Preferably, the neodymium iron boron sintered body comprises: Nd, 24mas%; Ho, 6mas%; Cu, 0.36mas%; C, 0.45mas%; Ga, 0.06mas%; Al, 0.04mas%; Ti, 0.1 mas%; Nb, 0.1mas%; Zr, 0.2mas%; B, 0.97mas%; the balance is Fe;

Preferably, the neodymium iron boron sintered body comprises: Nd, 22.8mas%; Ho, 7mas%; Cu, 0.6mas%; C, 0.45mas%; Ga, 0.15mas%; Al, 0.02mas%; Co, 0.2mas%; Nb, 0.1mas%; Zr, 0.28mas%; Mn, 0.02mas%; B, 0.964mas%; the balance is Fe.
An application of the neodymium iron boron magnet material according to claim 4 or 5 or the neodymium iron boron sintered body according to claim 8 or 9 in the preparation of magnetic steel.