CN111524672B

CN111524672B - Neodymium-iron-boron magnet material, raw material composition, preparation method and application

Info

Publication number: CN111524672B
Application number: CN202010364133.2A
Authority: CN
Inventors: 王金磊; 黄清芳; 黎国妃; 汤志辉; 黄佳莹
Original assignee: Xiamen Tungsten Co Ltd; Fujian Changting Jinlong Rare Earth Co Ltd
Current assignee: Fujian Jinlong Rare Earth Co ltd
Priority date: 2020-04-30
Filing date: 2020-04-30
Publication date: 2021-11-26
Anticipated expiration: 2040-04-30
Also published as: CN111524672A; WO2021218699A1

Abstract

The invention discloses a neodymium iron boron magnet material, a raw material composition, a preparation method and application, wherein the raw material composition of the neodymium iron boron magnet material I comprises the following components: r: 29.5 to 32.5 wt%; r is a rare earth element and comprises rare earth metal R1 for smelting and rare earth metal R2 for grain boundary diffusion, wherein the content of R2 is 0.2-1 wt%; r1 includes Nd, Ho and Gd, and does not include Dy and/or Tb; r2 includes Dy and/or Tb; co: 0-0.5 wt%; b: 0.9-1.05 wt%; cu: 0 to 0.35 wt% and not 0; ga: 0 to 0.35 wt% and not 0; al: 0-0.5 wt%; x: 0.05-0.45 wt%; x comprises one or more of Ti, Nb, Zr, Hf, V, Mo, W, Ta and Cr; fe: 66 to 70 wt%. The magnetic material has high grain boundary continuity and good magnetic performance.

Description

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

Technical Field

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

Background

Nd-Fe-B permanent magnetic material₂Fe_l4The B compound is used as a matrix, has the advantages of high magnetic property, small thermal expansion coefficient, easy processing, low price and the like, is increased at the speed of 20-30 percent per year on average since the coming of the world, and becomes a permanent magnetic material with the most wide application. According to the preparation method, the Nd-Fe-B permanent magnet can be divided into three types of sintering, bonding and hot pressing, wherein the sintered magnet accounts for more than 80% of the total production and is most widely applied.

With the continuous optimization of the preparation process and the magnet components, the maximum magnetic energy product of the sintered Nd-Fe-B magnet is close to the theoretical value. With the rapid development of new industries such as wind power generation, hybrid electric vehicles, variable frequency air conditioners and the like in recent years, the demand of high-performance Nd-Fe-B magnets is more and more large, and meanwhile, the application in the high-temperature field also puts higher requirements on the performance, especially the coercive force, of sintered Nd-Fe-B magnets.

In the prior art, Co is the most used and effective element when manufacturing heat-resistant and corrosion-resistant sintered Nd-Fe-B magnets. This is because the addition of Co can reduce the temperature coefficient of the reversible temperature coefficient of magnetic induction, effectively increase the curie temperature, and can improve the corrosion resistance of NdFeB magnets. However, the addition of Co easily causes a sharp decrease in coercive force, and the cost of Co is high. Although Al is one of effective elements for improving the coercivity of a sintered Nd-Fe-B magnet, the addition of Al can reduce the wetting angle between a main phase and a surrounding liquid phase in the sintering process, so that the coercivity is improved by improving the microstructure between the main phase and the Nd-rich phase, and the Al addition can compensate for the coercivity reduction caused by the Co addition. However, excessive addition of Al deteriorates the remanence and Curie temperature.

Disclosure of Invention

The invention aims to overcome the defects that the Curie temperature and the corrosion resistance of the neodymium iron boron magnet in the prior art are improved by adding Co, the coercive force is easy to drop sharply and the price is high due to Co, and the residual magnetism and the Curie temperature are deteriorated due to Al, and provides a neodymium iron boron magnet material, a raw material composition, a preparation method and application. The magnet material of the invention has the advantages of high remanence and high coercivity.

The invention solves the technical problems through the following technical scheme:

a raw material composition of a neodymium iron boron magnet material I comprises:

R：29.5～32.5wt％；

the R is a rare earth element and comprises rare earth metal R1 for smelting and rare earth metal R2 for grain boundary diffusion, and the content of R2 is 0.2-1 wt%;

the R1 comprises Nd, Ho and Gd, and does not comprise Dy and/or Tb;

r2 includes Dy and/or Tb;

Co：0～0.5wt％；

B：0.9～1.05wt％；

cu: 0 to 0.35 wt% and not 0;

ga: 0 to 0.35 wt% and not 0;

Al：0～0.5wt％；

X：0.05～0.45wt％；

x comprises one or more of Ti, Nb, Zr, Hf, V, Mo, W, Ta and Cr;

Fe：66～70wt％；

and the weight percent is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material I.

In the invention, when other elements are added to the raw material composition of the neodymium iron boron magnet material I, the total weight of the raw material composition changes. In this case, the content of the existing elements other than Fe by weight is not changed for each element amount, and only the content of Fe is reduced. That is, when some element is newly added, only the percentage of the Fe element is adjusted, and the percentages of other existing elements are not changed, so as to realize that the total content of each element is 100%.

In the present invention, the content of R is preferably 29.9 to 32 wt%, for example, 29.95 wt%, 30.2 wt%, 30.5 wt%, 31.5 wt% or 31.8 wt%, where wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material i.

In the invention, the Nd content in the R1 is preferably 19.3 to 32 wt%, for example 31 wt%, 20 wt%, 21 wt% or 26 wt%, where wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material i.

In the invention, the content of Ho in the R1 is preferably 0-10 wt% and is not 0; for example, 7.5 wt%, 5.5 wt%, 4 wt%, 2.5 wt%, 0.5 wt%, 6.7 wt%, 1 wt%, 1.2 wt% or 8.4 wt%, and more preferably 0.5 to 4 wt% or 5.5 to 8.5 wt%, where wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material i.

In the invention, the content of Gd in the R1 is preferably 0-5 wt% and is not 0; for example, 1 wt%, 0.5 wt%, 0.4 wt%, 3 wt%, 0.2 wt% or 0.7 wt%, more preferably 0 to 3 wt%, and not 0, for example, 1 wt%, the wt% being the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material i.

Wherein the total mass of Gd and Ho added is preferably not more than 10 wt%.

In the present invention, the R1 preferably does not contain heavy rare earth metals other than Ho and Gd. The definition or class of heavy rare earth metals is conventional in the art and may include, for example, 9 elements such as terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, and yttrium after gadolinium.

In the present invention, the R1 may also include other rare earth elements conventional in the art, including, for example, Pr and/or Sm.

Wherein, when the R1 contains Pr, the addition form of Pr may be conventional in the art, for example, in the form of PrNd, or in the form of a pure mixture of Pr and Nd, or in combination of PrNd, pure mixture of Pr and Nd. When added as PrNd, the weight ratio of Pr to Nd in PrNd is 25:75 or 20: 80, e.g. 25: 75.

In the present invention, the addition form of Nd of R1 can be conventional in the art, for example, in the form of PrNd, or in the form of pure Nd, or in the form of a mixture of pure Pr and Nd, or in combination of PrNd, pure Pr and Nd. When added as PrNd, the weight ratio of Pr to Nd in PrNd is 25:75 or 20: 80, e.g. 25: 75.

In the present invention, when Nd and/or Pr in R1 is added as PrNd, the amount of PrNd is preferably 0.5 to 27.5 wt%, for example, 22.5 wt%, 24.5 wt%, 26 wt%, 27.5 wt%, 5.5 wt%, 1 wt%, or 0.5 wt%, and the wt% is the weight percentage of each element in the raw material composition of the neodymium iron boron magnet material i.

When R1 contains Pr, the content of Pr is preferably 0 to 16 wt%, and is not 0, and more preferably 0.2 to 7 wt%, where wt% is the mass percentage of each element in the raw material composition of the ndfeb magnet material i.

When the R1 contains Sm, the content of Sm is preferably 0 to 3 wt%, for example, 0.7 wt%, where wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material i.

In the invention, the content range of R2 is preferably 0.2 to 0.85 wt%, for example 0.5 wt% or 0.7 wt%, where wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material i.

When R2 includes Dy, the content of Dy is preferably in the range of 0.2 to 0.8 wt%, for example, 0.2 wt%, 0.4 wt% or 0.5 wt%, wt% being the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material i.

When R2 includes Tb, the content of Tb is preferably in the range of 0.05 to 0.7 wt%, such as 0.5 wt%, 0.3 wt% or 0.4 wt%, and wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material i.

In the present invention, when R2 is a mixture of Dy and Tb, the weight ratio of Dy and Tb may be conventional in the art, and is generally 1:99 to 99:1, such as 1:1, 3:2, 16:1 or 2: 3.

In the present invention, the content of Co is preferably 0 to 0.47 wt%, for example, 0.22 wt% or 0.35 wt%, where wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material i.

In the present invention, the content of B is preferably 0.94 to 1.02 wt%, for example, 0.99 wt% or 1 wt%, where wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material i.

In the present invention, the Cu content is preferably in the range of 0 to 0.3 wt%, for example, 0.02 wt%, 0.05 wt%, 0.11 wt%, 0.15 wt%, or 0.3 wt%; more preferably 0.02-0.15 wt%, wherein the wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material I.

In the present invention, the content of Ga is preferably in the range of 0 to 0.3 wt%, for example, 0.05 wt%, 0.15 wt%, 0.2 wt%, or 0.21 wt%; more preferably 0.05-0.15 wt%, wherein the wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material I.

In the present invention, the content of Al is in the range of 0 to 0.3 wt%, more preferably 0 to 0.1 wt%, such as 0.02 wt%, 0.04 wt% or 0.08 wt%; more preferably 0 to 0.04 wt%, wherein the wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material I. When the content of Al is 0-0.1 wt%, the content of Al can be in the range of impurity Al introduced in the process of preparing the neodymium iron boron material, or can be additionally added Al. When the content of Al is 0-0.04 wt%, the range is the content range of impurity Al introduced in the process of preparing the neodymium iron boron material.

In the present invention, preferably, the content of X is 0.05 to 0.3 wt% or 0.33 wt%, for example, 0.2 wt%, 0.3 wt% or 0.07 wt%.

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

When X includes Zr, the content of Zr is preferably in the range of 0.02 to 0.3 wt%, for example, 0.2 wt%, and wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material i.

When X includes Ti, the content range of Ti is preferably 0 to 0.2 wt%, and is not 0, for example, 0.02 wt%, where wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material i.

When X includes Nb, the content range of Nb is preferably 0 to 0.4 wt%, and is not 0, for example, 0.03 wt%, 0.1 wt%, and wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material i.

When X includes Hf, the content of Hf is preferably in the range of 0 to 0.1 wt%, and is not 0, for example, 0.03 wt% or 0.05 wt%, wt% being the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material i.

When X comprises Ti and Nb, the weight ratio of Ti to Nb can be conventional in the art, and is typically from 1:99 to 99:1, for example 2:1 or 2: 3.

When X comprises Hf and Zr, the weight ratio of Hf to Zr may be conventional in the art, and is typically 1:99 to 99:1, e.g., 1:10 or 5: 2.

When X comprises Hf and Nb, the weight ratio of Hf to Nb may be conventional in the art, and is typically 1:99 to 99:1, e.g., 1: 8.

In the invention, the raw material composition of the neodymium iron boron magnet material I can also comprise Mn. The content range of Mn is less than or equal to 0.035 wt%, and more preferably less than or equal to 0.0175 wt%.

In the present invention, preferably, the raw material composition of the neodymium iron boron magnet material i includes:

in R1: PrNd: 5.5-27.5 wt%; ho: 2.5-10 wt%; gd: 0 to 3 wt% and not 0; r2: 0.2-0.8 wt%; b: 0.94-1.02 wt%; cu: 0-0.3 wt%; ga: 0-0.3 wt%; al: 0 to 0.1 wt%; zr: 0.02-0.3 wt%; the balance of Fe and inevitable impurities;

in a preferred embodiment of the present invention, the raw material composition of the neodymium-iron-boron magnet material i includes:

in R1: PrNd: 22.5 wt%, Ho: 7.5 wt%, Gd: 1 wt%, in R2: dy: 0.5 wt%, B: 0.94 wt%, Cu: 0.15 wt%, Ga: 0.15 wt%, Al: 0.04 wt%, Zr: 0.2 wt%, and the balance of Fe and inevitable impurities.

in R1: PrNd: 24.5 wt%, Ho: 5.5 wt%, Gd: 1 wt%, in R2: dy: 0.5 wt%, B: 0.94 wt%, Cu: 0.15 wt%, Ga: 0.15 wt%, Al: 0.04 wt%, Zr: 0.2 wt%, and the balance of Fe and inevitable impurities.

in R1: PrNd: 26 wt%, Ho: 4 wt%, Gd: 1 wt%, in R2: dy: 0.5 wt%, B: 0.94 wt%, Cu: 0.15 wt%, Ga: 0.15 wt%, Al: 0.04 wt%, Zr: 0.2 wt%, and the balance of Fe and inevitable impurities.

in R1: PrNd: 27.5 wt%, Ho: 2.5 wt%, Gd: 1 wt%, in R2: dy: 0.5 wt%, B: 0.94 wt%, Cu: 0.15 wt%, Ga: 0.15 wt%, Al: 0.04 wt%, Zr: 0.2 wt%, and the balance of Fe and inevitable impurities.

in R1: PrNd: 22.5 wt%, Ho: 7.5 wt%, Gd: 1 wt%, in R2: dy: 0.5 wt%, Co: 0.22 wt%, B: 0.94 wt%, Cu: 0.15 wt%, Ga: 0.15 wt%, Al: 0.04 wt%, Zr: 0.2 wt%, and the balance of Fe and inevitable impurities.

in R1: PrNd: 24.5 wt%, Ho: 5.5 wt%, Gd: 1 wt%, in R2: dy: 0.5 wt%, Co: 0.47 wt%, B: 0.94 wt%, Cu: 0.15 wt%, Ga: 0.15 wt%, Al: 0.04 wt%, Zr: 0.2 wt%, and the balance of Fe and inevitable impurities.

in R1: nd: 19.3 to 32 wt%; ho: 0 to 10 wt% and not 0; gd: 0 to 5 wt% and not 0;

R2：0.2～0.8wt％；B：0.94～1.02wt％；Cu：0～0.3wt％；Ga：0～0.3wt％；Al：0～0.1wt％；

ti: 0 to 0.2 wt% and not 0; nb: 0 to 0.4 wt% and not 0;

the balance being Fe and unavoidable impurities.

in R1: nd: 31 wt%, Ho: 0.5 wt%, Gd: 0.5 wt%, in R2: tb: 0.5 wt%, B: 0.9 wt%, Cu: 0.05 wt%, Ga: 0.05 wt%, Al: 0.1 wt%, Ti: 0.2 wt%, Nb: 0.1 wt%, and the balance of Fe and inevitable impurities.

in R1: nd: 19.3 wt%, Pr: 3.3 wt%, Ho: 6.7 wt%, Gd: 0.4 wt%, in R2: dy: 0.2 wt%, Tb: 0.3 wt%, B: 0.99 wt%, Cu: 0.02 wt%, Ga: 0.2 wt%, Al: 0.5 wt%, Ti: 0.02 wt%, Nb: 0.03 wt%, and the balance of Fe and inevitable impurities.

in R1: nd: 19.3 to 32 wt%; ho: 0 to 10 wt% and not 0; gd: 0 to 5 wt% and not 0;

zr: 0.02-0.3 wt%; hf: 0 to 0.1 wt% and not 0;

the balance being Fe and unavoidable impurities.

in R1: nd: 20 wt%, PrNd: 5.5 wt%, Ho: 1.2 wt%, Gd: 3 wt%, in R2: dy: 0.4 wt%, Tb: 0.4 wt%, B: 1 wt%, Cu: 0.11 wt%, Ga: 0.3 wt%, Al: 0.3 wt%, Hf: 0.03 wt%, Zr: 0.3 wt%, and the balance of Fe and inevitable impurities.

in R1: nd: 26 wt%, Pr: 0.2 wt%, PrNd: 0.5 wt%, Ho: 1 wt%, Gd: 0.7 wt%, Sm: 0.7 wt%, in R2: dy: 0.8 wt%, Tb: 0.05 wt%, B: 1.02 wt%, Cu: 0.3 wt%, Ga: 0.21 wt%, Al: 0.02 wt%, Zr: 0.02 wt%, Hf: 0.05 wt%, and the balance of Fe and inevitable impurities.

in R1: nd: 19.3 to 32 wt%; ho: 0 to 10 wt% and not 0; gd: 0 to 5 wt% and not 0;

hf: 0 to 0.1 wt% and not 0; nb: 0 to 0.4 wt% and not 0;

the balance being Fe and unavoidable impurities.

in R1: nd: 21 wt%, Pr: 0.5 wt%, PrNd: 1 wt%, Ho: 8.4 wt%, Gd: 0.2 wt%, in R2: tb: 0.7 wt%, B: 1.02 wt%, Cu: 0.3 wt%, Ga: 0.21 wt%, Al: 0.08 wt%, Nb: 0.4 wt%, Hf: 0.05 wt%, and the balance of Fe and inevitable impurities.

The invention also provides a preparation method of the neodymium iron boron magnet material I, which is carried out by adopting the raw material composition, and the preparation method is a conventional diffusion preparation method in the field, wherein the R1 element is added in a smelting step, and the R2 element is added in a grain boundary diffusion step.

In the present invention, the preparation method preferably comprises the steps of: the elements except R2 in the raw material composition of the neodymium iron boron magnet material I are smelted, pulverized, molded and sintered to obtain a sintered body, and then the mixture of the sintered body and the R2 is diffused through a grain boundary.

In the invention, the smelting operation and conditions can be conventional smelting processes in the field, and elements except for R2 in the raw material composition of the neodymium iron boron magnet material i are generally smelted and cast by an ingot casting process and a rapid hardening sheet process to obtain an alloy sheet.

As known to those skilled in the art, since rare earth elements are usually lost in the melting and sintering processes, in order to ensure the quality of a final product, 0 to 0.3 wt% of a rare earth element (generally Nd element) is generally additionally added to the formula of a raw material composition in the melting process, wherein the percentage is the mass percentage of the additionally added rare earth element in the total content of the raw material composition; in addition, the content of the additionally added rare earth elements is not included in the category of the raw material composition.

In the invention, the smelting temperature can be 1300-1700 ℃.

In the invention, the smelting equipment is generally a medium-frequency vacuum smelting furnace, such as a medium-frequency vacuum induction rapid hardening melt-spun furnace.

The operation and conditions of the powder preparation can be conventional powder preparation process in the field, and generally comprise hydrogen powder preparation and/or airflow powder preparation.

The hydrogen pulverized powder generally comprises hydrogen absorption, dehydrogenation and cooling treatment. The temperature of the hydrogen absorption is generally 20-200 ℃. The dehydrogenation temperature is generally 400-650 ℃. The pressure of the hydrogen absorption is generally 50 to 600 kPa.

The jet milling powder is generally subjected to jet milling under the condition of 0.1-2 MPa, preferably 0.5-0.7 MPa. The gas flow in the gas flow milled powder can be, for example, nitrogen and/or argon. The efficiency of the airflow powder grinding can be different according to different equipment, such as 30-400 kg/h, and further such as 200 kg/h.

The molding operation and conditions may be those conventional in the art. Such as magnetic field molding. The magnetic field intensity of the magnetic field forming method is generally 1.5T or more.

In the present invention, the sintering operation and conditions may be sintering processes conventional 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 all conventional operations in the field. When an inert atmosphere sintering process is adopted, the sintering starting stage can be carried out at a vacuum degree of less than 5X 10^-1Pa, and the like.The inert gas atmosphere may be an atmosphere containing an inert gas, which is conventional in the art, and is not limited to helium, argon.

Wherein, the sintering temperature can be 1000-1200 ℃, and preferably is 1030-1090 ℃.

The sintering time can be 0.5-10 h, preferably 2-8 h.

The grain boundary diffusion treatment may be performed according to a conventional process in the art, for example, the grain boundary diffusion treatment may be performed by an R2 coating operation, a vapor physical deposition operation, or an evaporation operation. The R2 is typically coated in the form of a fluoride or low melting point alloy, such as an alloy of Tb or fluoride. When the R2 further contains Dy, it is preferable that Dy is coated in the form of an alloy or fluoride of Dy.

The gas-phase physical precipitation operation generally refers to magnetron plasma sputtering, heavy rare earth Dy and/or Tb target materials are bombarded by inert gas to generate heavy rare earth Dy and/or Tb ions, and the heavy rare earth Dy and/or Tb ions are uniformly attached to the surface of a base material under the control of a magnetic field. The vapor deposition method generally refers to that vapor of the heavy rare earth Dy and/or Tb is generated at a certain vacuum degree (such as 5-0.05 Pa) and a certain temperature (such as 500-.

Wherein the temperature of the grain boundary diffusion can be 800-1000 ℃, such as 900 ℃.

The time of the grain boundary diffusion can be 12-90 h, such as 24 h.

Wherein, after the grain boundary diffusion, heat treatment is also performed according to the conventional method in the field.

Wherein the temperature of the heat treatment can be 450-600 ℃, for example 480-510 ℃.

Wherein, the time of the heat treatment can be 2 to 4 hours, such as 3 hours.

The invention also provides the neodymium iron boron magnet material I prepared by the preparation method.

The invention also provides a neodymium iron boron magnet material I, which comprises the following components:

R：29.5～32.5wt％；

the R is a rare earth element and comprises a rare earth element R1 and a rare earth element R2, and the content of R2 is 0.2-1 wt%;

the R1 comprises Nd, Ho and Gd, and does not comprise Dy and/or Tb;

r2 includes Dy and/or Tb;

Co：0～0.5wt％；

B：0.9～1.05wt％；

cu: 0 to 0.35 wt% and not 0;

ga: 0 to 0.35 wt% and not 0;

Al：0～0.5wt％；

X：0.05～0.45wt％；

x comprises one or more of Ti, Nb, Zr, Hf, V, Mo, W, Ta and Cr;

fe: 66-70 wt%; the weight percent is the mass percentage of each element in the neodymium iron boron magnet material I;

the neodymium iron boron magnet material I comprises Nd₂Fe_l4B crystal grains and a shell layer thereof, a grain boundary epitaxial layer and a neodymium-rich phase;

ho in the R1 is mainly distributed in the Nd₂Fe_l4B crystal grains and the grain boundary epitaxial layer, wherein the R2 is mainly distributed in the shell layer and the neodymium-rich phase;

the grain boundary continuity of the neodymium iron boron magnet material is more than 96.5%.

In the invention, when other elements are added into the neodymium iron boron magnet material I, the total weight of the raw material composition changes. In this case, the content of the existing elements other than Fe by weight is not changed for each element amount, and only the content of Fe is reduced. That is, when some element is newly added, only the percentage of the Fe element is adjusted, and the percentages of other existing elements are not changed, so as to realize that the total content of each element is 100%.

In the present invention, "Ho in R1 is mainly distributed in the Nd₂Fe_l4The "main distribution" in the B grains and the grain boundary epitaxial layer generally means that 95% or more of the element is distributed in the neodymium-rich phase, and only a small portion is distributed. "R2 is distributed mainly in the shell layer and the neodymium-rich phase" can be understood as being caused by the grain boundary diffusion process which is conventional in the artR2 (R) is mainly distributed (generally, more than 95%) in the shell and grain boundaries of the main phase grains, and a small amount of R also diffuses into the main phase grains, for example, at the outer edges of the main phase grains.

In the present invention, the grain boundary epitaxial layer generally refers to a two-particle grain boundary adjacent to the neodymium-rich phase and the main phase particle, and may also be referred to as a "two-particle grain boundary" or a "grain boundary edge shell structure of the main phase and the neodymium-rich phase".

In the present invention, the neodymium-rich phase is a neodymium-rich phase conventionally understood in the art, and in the art, most of the phase structure in the grain boundary structure is a neodymium-rich phase.

In the present invention, the calculation method of grain boundary continuity refers to the ratio of the length occupied by phases other than voids (for example, neodymium-rich phase and the same phase in the grain boundary epitaxial layer) in the grain boundary to the total grain boundary length. If the continuity of the grain boundary exceeds 96%, the channel is called a continuous channel.

In the present invention, the grain boundary continuity is preferably 96.6% or more, for example, 96.8%, 96.9%, 96.66%, 97.1%, 97.2%, or 96.7%.

In the present invention, preferably, the grain boundary epitaxial layer contains R_40-85Ho_0.1-10Gd_0.1-5Cu_0.1-2.0X_3-7Wherein R, X is as defined above.

In the present invention, the content of R is preferably 29.9 to 31.8 wt%, for example, 29.95 wt%, 30.2 wt%, 30.5 wt% or 31.5 wt%, where wt% is the mass percentage of each element in the neodymium iron boron magnet material i.

In the invention, the Nd content in the R1 is preferably 19.3 to 32 wt%, for example 31 wt%, 20 wt%, 21 wt% or 26 wt%, where wt% is the mass percentage of each element in the neodymium iron boron magnet material i.

In the invention, the content of Ho in the R1 is preferably 0-10 wt% and is not 0; for example, 7.5 wt%, 5.5 wt%, 4 wt%, 2.5 wt%, 0.5 wt%, 6.7 wt%, 1 wt%, 1.2 wt% or 8.4 wt%, and more preferably 0.5 to 4 wt% or 5.5 to 8.5 wt%, where wt% is the mass percentage of each element in the neodymium iron boron magnet material i.

In the invention, the content of Gd in the R1 is preferably 0-5 wt% and is not 0; for example, 1 wt%, 0.5 wt%, 0.4 wt%, 3 wt%, 0.2 wt% or 0.7 wt%, more preferably 0 to 3 wt%, and not 0, for example, 1 wt%, wt% being the mass percentage of each element in the neodymium iron boron magnet material i.

Wherein the total mass of Gd and Ho added is preferably not more than 10 wt%.

When R1 contains Pr, the content of Pr is preferably 0 to 16 wt%, and is not 0, and more preferably 0.2 to 7 wt%, where wt% is the mass percentage of each element in the ndfeb magnet material i.

When the R1 contains Sm, the content of Sm is preferably 0 to 3 wt%, for example, 0.7 wt%, where wt% is the mass percentage of each element in the neodymium iron boron magnet material i.

In the invention, the content range of the R2 is preferably 0.2 to 0.85 wt%, for example, 0.5 wt%, 0.7 wt% or 0.8 wt%, where wt% is the mass percentage of each element in the neodymium iron boron magnet material i.

When R2 includes Dy, the content of Dy is preferably in the range of 0.2 to 0.8 wt%, for example 0.2 wt%, 0.4 wt% or 0.5 wt%, wt% being the mass percentage of each element in the neodymium iron boron magnet material i.

When R2 includes Tb, the content of Tb is preferably in the range of 0.05 to 0.7 wt%, such as 0.5 wt%, 0.3 wt% or 0.4 wt%, wt% being the mass percentage of each element in the neodymium iron boron magnet material i.

In the present invention, the content of Co is preferably 0 to 0.47 wt%, for example, 0.22 wt% or 0.35 wt%, where wt% is the mass percentage of each element in the neodymium iron boron magnet material i.

In the present invention, the content range of B is preferably 0.94 to 1.02 wt%, for example, 0.99 wt% or 1 wt%, where wt% is the mass percentage of each element in the neodymium iron boron magnet material i.

In the present invention, the Cu content is preferably in the range of 0 to 0.3 wt%, for example, 0.02 wt%, 0.05 wt%, 0.11 wt%, 0.15 wt%, or 0.3 wt%; more preferably 0.02-0.15 wt%, wherein wt% is the mass percentage of each element in the neodymium iron boron magnet material I.

In the present invention, the content of Ga is preferably in the range of 0 to 0.3 wt%, for example, 0.05 wt%, 0.15 wt%, 0.2 wt%, or 0.21 wt%; more preferably 0.05-0.15 wt%, wherein wt% is the mass percentage of each element in the neodymium iron boron magnet material I.

In the present invention, the content of Al is in the range of 0 to 0.3 wt%, more preferably 0 to 0.1 wt%, such as 0.02 wt%, 0.04 wt% or 0.08 wt%; more preferably 0-0.04 wt%, wherein wt% is the mass percentage of each element in the neodymium iron boron magnet material I. When the content of Al is 0-0.1 wt%, the content of Al can be in the content range of impurity Al introduced in the process of preparing the neodymium iron boron material, or can be additionally added Al. When the content of Al is 0-0.04 wt%, the range is the content range of impurity Al introduced in the process of preparing the neodymium iron boron material.

When X includes Zr, the content of Zr is preferably in the range of 0.02 to 0.3 wt%, for example, 0.2 wt%, and wt% is the mass percentage of each element in the neodymium iron boron magnet material i.

When X includes Ti, the content of Ti is preferably in a range of 0 to 0.2 wt%, for example, 0.02 wt%, where wt% is the mass percentage of each element in the neodymium iron boron magnet material i.

When X includes Nb, the content of Nb is preferably in the range of 0 to 0.4 wt%, for example, 0.03 wt%, 0.1 wt%, where wt% is the mass percentage of each element in the neodymium iron boron magnet material i.

When X includes Hf, the content of Hf is preferably in the range of 0 to 0.1 wt%, for example 0.03 wt% or 0.05 wt%, wt% being the mass percentage of each element in the neodymium iron boron magnet material i.

In the invention, the neodymium iron boron magnet material I can also comprise Mn. The content range of Mn is less than or equal to 0.035 wt%, and more preferably less than or equal to 0.0175 wt%.

In the present invention, preferably, the neodymium iron boron magnet material i includes:

in R1: PrNd: 5.5-27.5 wt%; ho: 2.5-10 wt%; gd: 0 to 3 wt% and not 0; r2: 0.2-0.8 wt%; b: 0.94-1.02 wt%; cu: 0-0.3 wt%; ga: 0-0.3 wt%; al: 0 to 0.1 wt%; zr: 0.02-0.3 wt%; the balance being Fe and unavoidable impurities.

In a preferred embodiment of the present invention, the ndfeb magnet material i includes:

in R1: PrNd: 22.5 wt%, Ho: 7.5 wt%, Gd: 1 wt%, in R2: dy: 0.5 wt%, B: 0.94 wt%, Cu: 0.15 wt%, Ga: 0.15 wt%, Al: 0.04 wt%, Zr: 0.2 wt%, grain boundary continuity of 96.8%, and the balance of Fe and inevitable impurities.

in R1: PrNd: 24.5 wt%, Ho: 5.5 wt%, Gd: 1 wt%, in R2: dy: 0.5 wt%, B: 0.94 wt%, Cu: 0.15 wt%, Ga: 0.15 wt%, Al: 0.04 wt%, Zr: 0.2 wt%, grain boundary continuity of 96.9%, and the balance of Fe and inevitable impurities.

in R1: PrNd: 26 wt%, Ho: 4 wt%, Gd: 1 wt%, in R2: dy: 0.5 wt%, B: 0.94 wt%, Cu: 0.15 wt%, Ga: 0.15 wt%, Al: 0.04 wt%, Zr: 0.2 wt%, grain boundary continuity of 96.66%, and the balance of Fe and inevitable impurities.

in R1: PrNd: 27.5 wt%, Ho: 2.5 wt%, Gd: 1 wt%, in R2: dy: 0.5 wt%, B: 0.94 wt%, Cu: 0.15 wt%, Ga: 0.15 wt%, Al: 0.04 wt%, Zr: 0.2 wt%, grain boundary continuity of 97.1%, and the balance of Fe and inevitable impurities.

in R1: PrNd: 22.5 wt%, Ho: 7.5 wt%, Gd: 1 wt%, in R2: dy: 0.5 wt%, Co: 0.22 wt%, B: 0.94 wt%, Cu: 0.15 wt%, Ga: 0.15 wt%, Al: 0.04 wt%, Zr: 0.2 wt%, grain boundary continuity of 96.3%, and the balance of Fe and inevitable impurities.

in R1: PrNd: 24.5 wt%, Ho: 5.5 wt%, Gd: 1 wt%, in R2: dy: 0.5 wt%, Co: 0.47 wt%, B: 0.94 wt%, Cu: 0.15 wt%, Ga: 0.15 wt%, Al: 0.04 wt%, Zr: 0.2 wt%, grain boundary continuity of 96.1%, and the balance of Fe and inevitable impurities.

in R1: nd: 19.3 to 32 wt%; ho: 0 to 10 wt% and not 0; gd: 0 to 5 wt% and not 0;

ti: 0 to 0.2 wt% and not 0; nb: 0 to 0.4 wt% and not 0;

the balance being Fe and unavoidable impurities.

in R1: nd: 31 wt%, Ho: 0.5 wt%, Gd: 0.5 wt%, in R2: tb: 0.5 wt%, B: 0.9 wt%, Cu: 0.05 wt%, Ga: 0.05 wt%, Al: 0.1 wt%, Ti: 0.2 wt%, Nb: 0.1 wt%, grain boundary continuity of 97.2%, and the balance of Fe and inevitable impurities.

in R1: nd: 19.3 wt%, Pr: 3.3 wt%, Ho: 6.7 wt%, Gd: 0.4 wt%, in R2: dy: 0.2 wt%, Tb: 0.3 wt%, B: 0.99 wt%, Cu: 0.02 wt%, Ga: 0.2 wt%, Al: 0.5 wt%, Ti: 0.02 wt%, Nb: 0.03 wt%, grain boundary continuity of 96.5%, and the balance of Fe and inevitable impurities.

in R1: nd: 19.3 to 32 wt%; ho: 0 to 10 wt% and not 0; gd: 0 to 5 wt% and not 0;

zr: 0.02-0.3 wt%; hf: 0 to 0.1 wt% and not 0;

the balance being Fe and unavoidable impurities.

in R1: nd: 20 wt%, PrNd: 5.5 wt%, Ho: 1.2 wt%, Gd: 3 wt%, in R2: dy: 0.4 wt%, Tb: 0.4 wt%, B: 1 wt%, Cu: 0.11 wt%, Ga: 0.3 wt%, Al: 0.3 wt%, Hf: 0.03 wt%, Zr: 0.3 wt%, grain boundary continuity of 96.7%, and the balance of Fe and inevitable impurities.

in R1: nd: 26 wt%, Pr: 0.2 wt%, PrNd: 0.5 wt%, Ho: 1 wt%, Gd: 0.7 wt%, Sm: 0.7 wt%, in R2: dy: 0.8 wt%, Tb: 0.05 wt%, B: 1.02 wt%, Cu: 0.3 wt%, Ga: 0.21 wt%, Al: 0.02 wt%, Zr: 0.02 wt%, Hf: 0.05 wt%, grain boundary continuity of 97.1%, and the balance of Fe and inevitable impurities.

in R1: nd: 19.3 to 32 wt%; ho: 0 to 10 wt% and not 0; gd: 0 to 5 wt% and not 0;

hf: 0 to 0.1 wt% and not 0; nb: 0 to 0.4 wt% and not 0;

the balance being Fe and unavoidable impurities.

in R1: nd: 21 wt%, Pr: 0.5 wt%, PrNd: 1 wt%, Ho: 8.4 wt%, Gd: 0.2 wt%, in R2: tb: 0.7 wt%, B: 1.02 wt%, Cu: 0.3 wt%, Ga: 0.21 wt%, Al: 0.08 wt%, Nb: 0.4 wt%, Hf: 0.05 wt%, grain boundary continuity of 96.8%, and the balance of Fe and inevitable impurities.

The invention also provides a raw material composition of the neodymium iron boron magnet material II, which comprises the following components:

R：29～32.2wt％；

the R is a rare earth element, comprises Nd, Ho and Gd, and does not comprise Dy and/or Tb; ,

Co：0～0.5wt％；

B：0.9～1.05wt％；

cu: 0 to 0.35 wt% and not 0;

ga: 0 to 0.35 wt% and not 0;

Al：0～0.5wt％；

X：0.05～0.45wt％；

x comprises one or more of Ti, Nb, Zr, Hf, V, Mo, W, Ta and Cr;

Fe：66.6～70wt％；

the weight percent is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material II.

In the present invention, when other elements are added to the raw material composition of the neodymium iron boron magnet material ii, the total weight of the raw material composition changes. In this case, the content of the existing elements other than Fe by weight is not changed for each element amount, and only the content of Fe is reduced. That is, when some element is newly added, only the percentage of the Fe element is adjusted, and the percentages of other existing elements are not changed, so as to realize that the total content of each element is 100%.

In the invention, the content of R is 29.1 to 31.2 wt%, for example, 29.3 wt%, 31 wt%, 31.1 wt%, 29.9 wt% or 29.8 wt%, and the wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material ii.

In the present invention, the Nd content in R is preferably 19.3 to 32 wt%, for example, 31.2 wt%, 19.4 wt%, 20.2 wt%, 21.1 wt%, or 26.2 wt%, where wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material ii.

In the invention, the content of Ho in the R is preferably 0-10 wt% and is not 0; for example, 7.5 wt%, 5.5 wt%, 4 wt%, 2.5 wt%, 0.5 wt%, 6.7 wt%, 1 wt%, 1.2 wt% or 8.5 wt%, and more preferably 0.5 to 4 wt% or 5.5 to 8.5 wt%, where wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material ii.

In the invention, the content of Gd in the R is preferably 0-5 wt% and is not 0; for example, 1 wt%, 0.5 wt%, 0.4 wt%, 3 wt%, 0.2 wt% or 0.7 wt%, more preferably 0 to 3 wt%, and not 0, for example, 1 wt%, the wt% being the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material ii.

Wherein the total mass of Gd and Ho added is preferably not more than 10 wt%.

In the present invention, the R preferably does not contain heavy rare earth metals other than Ho and Gd. The definition or class of heavy rare earth metals is conventional in the art and may include, for example, 9 elements such as terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, and yttrium after gadolinium.

In the present invention, the R may further comprise other rare earth elements conventional in the art, for example, Pr and/or Sm.

Wherein, when said R comprises Pr, the addition form of Pr may be conventional in the art, for example, in the form of PrNd, or in the form of a pure mixture of Pr and Nd, or in combination of PrNd, pure Pr and Nd. When added as PrNd, the weight ratio of Pr to Nd in PrNd is 25:75 or 20: 80, e.g. 25: 75.

In the present invention, the addition form of Nd of R may be conventional in the art, for example, in the form of PrNd, or in the form of pure Nd, or in the form of a mixture of pure Pr and Nd, or in combination with a mixture of PrNd, pure Pr and Nd. When added as PrNd, the weight ratio of Pr to Nd in PrNd is 25:75 or 20: 80, e.g. 25: 75.

In the present invention, when Nd and/or Pr in R1 is added as PrNd, the amount of PrNd is preferably 0.5 to 27.5 wt%, for example, 22.5 wt%, 24.5 wt%, 26 wt%, 27.5 wt%, 5.5 wt%, 1 wt%, or 0.5 wt%, and the wt% is the weight percentage of each element in the raw material composition of the neodymium iron boron magnet material ii.

When R contains Pr, the content of Pr is preferably 0 to 16 wt%, and is not 0, and more preferably 0.2 to 7 wt%, where wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material ii.

When the R contains Sm, the content of Sm is preferably 0 to 3 wt%, for example, 0.7 wt%, and the wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material ii.

In the present invention, the content of Co is preferably 0 to 0.47 wt%, for example, 0.22 wt% or 0.35 wt%, where wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material ii.

In the present invention, the content of B is preferably 0.94 to 1.02 wt%, for example, 0.99 wt% or 1 wt%, where wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material ii.

In the present invention, the Cu content is preferably in the range of 0 to 0.3 wt%, for example, 0.02 wt%, 0.05 wt%, 0.11 wt%, 0.15 wt%, or 0.3 wt%; more preferably 0.02-0.15 wt%, wherein the wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material II.

In the present invention, the content of Ga is preferably in the range of 0 to 0.3 wt%, for example, 0.05 wt%, 0.15 wt%, 0.2 wt%, or 0.21 wt%; more preferably 0.05 to 0.15 wt%, wherein the wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material II.

In the present invention, the content of Al is in the range of 0 to 0.3 wt%, more preferably 0 to 0.1 wt%, such as 0.02 wt%, 0.04 wt% or 0.08 wt%; more preferably 0 to 0.04 wt%, wherein the wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material II. When the content of Al is 0-0.1 wt%, the content of Al can be in the content range of impurity Al introduced in the process of preparing the neodymium iron boron material, or can be additionally added Al. When the content of Al is 0-0.04 wt%, the range is the content range of impurity Al introduced in the process of preparing the neodymium iron boron material.

When X includes Zr, the content of Zr is preferably in the range of 0.02 to 0.3 wt%, for example, 0.2 wt%, and wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material ii.

When X includes Ti, the content range of Ti is preferably 0 to 0.2 wt%, and is not 0, for example, 0.02 wt%, where wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material ii.

When X includes Nb, the content range of Nb is preferably 0 to 0.4 wt%, and is not 0, for example, 0.03 wt%, 0.1 wt%, and wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material ii.

When X includes Hf, the content of Hf is preferably in the range of 0 to 0.1 wt% and not 0, for example, 0.03 wt% or 0.05 wt%, wt% being the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material ii.

In the invention, the raw material composition of the neodymium iron boron magnet material II can also comprise Mn. The content range of Mn is less than or equal to 0.035 wt%, and more preferably less than or equal to 0.0175 wt%.

In the present invention, preferably, the raw material composition of the neodymium iron boron magnet material ii includes:

PrNd: 5.5-27.5 wt%; ho: 2.5-10 wt%; gd: 0 to 3 wt% and not 0; b: 0.94-1.02 wt%; cu: 0-0.3 wt%; ga: 0-0.3 wt%; al: 0 to 0.1 wt%; zr: 0.02-0.3 wt%; the balance being Fe and unavoidable impurities.

In a preferred embodiment of the present invention, the raw material composition of the neodymium-iron-boron magnet material ii includes:

PrNd: 22.6 wt%, Ho: 7.5 wt%, Gd: 1 wt%, B: 0.94 wt%, Cu: 0.15 wt%, Ga: 0.15 wt%, Al: 0.04 wt%, Zr: 0.2 wt%, and the balance of Fe and inevitable impurities.

PrNd: 24.6 wt%, Ho: 5.5 wt%, Gd: 1 wt%, B: 0.94 wt%, Cu: 0.15 wt%, Ga: 0.15 wt%, Al: 0.04 wt%, Zr: 0.2 wt%, and the balance of Fe and inevitable impurities.

PrNd: 26.1 wt%, Ho: 4 wt%, Gd: 1 wt%, B: 0.94 wt%, Cu: 0.15 wt%, Ga: 0.15 wt%, Al: 0.04 wt%, Zr: 0.2 wt%, and the balance of Fe and inevitable impurities.

PrNd: 27.6 wt%, Ho: 2.5 wt%, Gd: 1 wt%, B: 0.94 wt%, Cu: 0.15 wt%, Ga: 0.15 wt%, Al: 0.04 wt%, Zr: 0.2 wt%, and the balance of Fe and inevitable impurities.

PrNd: 22.6 wt%, Ho: 7.5 wt%, Gd: 1 wt%, Co: 0.22 wt%, B: 0.94 wt%, Cu: 0.15 wt%, Ga: 0.15 wt%, Al: 0.04 wt%, Zr: 0.2 wt%, and the balance of Fe and inevitable impurities.

PrNd: 24.6 wt%, Ho: 5.5 wt%, Gd: 1 wt%, Co: 0.47 wt%, B: 0.94 wt%, Cu: 0.15 wt%, Ga: 0.15 wt%, Al: 0.04 wt%, Zr: 0.2 wt%, and the balance of Fe and inevitable impurities.

nd: 19.3 to 32 wt%; ho: 0 to 10 wt% and not 0; gd: 0 to 5 wt% and not 0; b: 0.94-1.02 wt%; cu: 0-0.3 wt%; ga: 0-0.3 wt%; al: 0 to 0.1 wt%; ti: 0 to 0.2 wt% and not 0; nb: 0 to 0.4 wt% and not 0;

the balance being Fe and unavoidable impurities.

nd: 31 wt%, Ho: 0.5 wt%, Gd: 0.5 wt%, Tb: 0.5 wt%, B: 0.9 wt%, Cu: 0.05 wt%, Ga: 0.05 wt%, Al: 0.1 wt%, Ti: 0.2 wt%, Nb: 0.1 wt%, and the balance of Fe and inevitable impurities.

nd: 19.3 wt%, Pr: 3.3 wt%, Ho: 6.7 wt%, Gd: 0.4 wt%, B: 0.99 wt%, Cu: 0.02 wt%, Ga: 0.2 wt%, Al: 0.5 wt%, Ti: 0.02 wt%, Nb: 0.03 wt%, and the balance of Fe and inevitable impurities.

nd: 19.3 to 32 wt%; ho: 0 to 10 wt% and not 0; gd: 0 to 5 wt% and not 0; b: 0.94-1.02 wt%; cu: 0-0.3 wt%; ga: 0-0.3 wt%; al: 0 to 0.1 wt%; zr: 0.02-0.3 wt%; hf: 0 to 0.1 wt% and not 0;

the balance being Fe and unavoidable impurities.

nd: 20 wt%, PrNd: 5.5 wt%, Ho: 1.2 wt%, Gd: 3 wt%, B: 1 wt%, Cu: 0.11 wt%, Ga: 0.3 wt%, Al: 0.3 wt%, Hf: 0.03 wt%, Zr: 0.3 wt%, and the balance of Fe and inevitable impurities.

nd: 26 wt%, Pr: 0.2 wt%, PrNd: 0.5 wt%, Ho: 1 wt%, Gd: 0.7 wt%, Sm: 0.7 wt%, B: 1.02 wt%, Cu: 0.3 wt%, Ga: 0.21 wt%, Al: 0.02 wt%, Zr: 0.02 wt%, Hf: 0.05 wt%, and the balance of Fe and inevitable impurities.

nd: 19.3 to 32 wt%; ho: 0 to 10 wt% and not 0; gd: 0 to 5 wt% and not 0;

b: 0.94-1.02 wt%; cu: 0-0.3 wt%; ga: 0-0.3 wt%; al: 0 to 0.1 wt%; hf: 0 to 0.1 wt% and not 0; nb: 0 to 0.4 wt% and not 0;

the balance being Fe and unavoidable impurities.

nd: 21 wt%, Pr: 0.5 wt%, PrNd: 1 wt%, Ho: 8.5 wt%, Gd: 0.2 wt%, B: 1.02 wt%, Cu: 0.3 wt%, Ga: 0.21 wt%, Al: 0.08 wt%, Nb: 0.4 wt%, Hf: 0.05 wt%, and the balance of Fe and inevitable impurities.

The invention also provides a preparation method of the neodymium iron boron magnet material II, which is implemented by smelting, milling, molding and sintering the raw material composition of the neodymium iron boron magnet material II.

Wherein the processes of the smelting, the milling, the forming and the sintering are the same as above.

The invention also provides a neodymium iron boron magnet material II prepared by the preparation method.

The invention also provides a neodymium iron boron magnet material II, which comprises the following components:

R：29～32.2wt％；

Co：0～0.5wt％；

B：0.9～1.05wt％；

cu: 0 to 0.35 wt% and not 0;

ga: 0 to 0.35 wt% and not 0;

Al：0～0.5wt％；

X：0.05～0.45wt％；

x comprises one or more of Ti, Nb, Zr, Hf, V, Mo, W, Ta and Cr;

Fe：66.6～70wt％；

and the weight percent is the mass percentage of each element in the neodymium iron boron magnet material II.

In the invention, preferably, the neodymium-iron-boron magnet material ii comprises main phase particles, a neodymium-rich phase and a grain boundary epitaxial layer, and the grain boundary epitaxial layer contains R_40-85Ho_0.1-10Gd_0.1-5Cu_0.1-2.0X_3-7Wherein R, X is as defined above.

In the invention, when other elements are added into the neodymium iron boron magnet material II, the total weight of the raw material composition is changed. In this case, the content of the existing elements other than Fe by weight is not changed for each element amount, and only the content of Fe is reduced. That is, when some element is newly added, only the percentage of the Fe element is adjusted, and the percentages of other existing elements are not changed, so as to realize that the total content of each element is 100%.

In the invention, the content of R is 29.1 to 31.2 wt%, for example, 29.3 wt%, 31 wt%, 31.1 wt%, 29.9 wt% or 29.8 wt%, and the wt% is the mass percentage of each element in the neodymium iron boron magnet material ii.

In the present invention, the Nd content in R is preferably 19.3 to 32 wt%, for example, 31.2 wt%, 19.4 wt%, 20.2 wt%, 21.1 wt%, or 26.2 wt%, where wt% is the mass percentage of each element in the neodymium iron boron magnet material ii.

In the invention, the content of Ho in the R is preferably 0-10 wt% and is not 0; for example, 7.5 wt%, 5.5 wt%, 4 wt%, 2.5 wt%, 0.5 wt%, 6.7 wt%, 1 wt%, 1.2 wt% or 8.5 wt%, and more preferably 0.5 to 4 wt% or 5.5 to 8.5 wt%, where wt% is the mass percentage of each element in the neodymium iron boron magnet material ii.

In the invention, the content of Gd in the R is preferably 0-5 wt% and is not 0; for example, 1 wt%, 0.5 wt%, 0.4 wt%, 3 wt%, 0.2 wt% or 0.7 wt%, more preferably 0 to 3 wt%, and not 0, for example, 1 wt%, wt% being the mass percentage of each element in the neodymium iron boron magnet material ii.

Wherein the total mass of Gd and Ho added is preferably not more than 10 wt%.

When R contains Pr, the content of Pr is preferably 0 to 16 wt%, and is not 0, and more preferably 0.2 to 7 wt%, where wt% is the mass percentage of each element in the neodymium iron boron magnet material ii.

When R comprises Sm, the content of Sm is preferably 0-3 wt%, for example 0.7 wt%, and the wt% is the mass percentage of each element in the neodymium iron boron magnet material II.

In the present invention, the content of Co is preferably 0 to 0.47 wt%, for example, 0.22 wt% or 0.35 wt%, where wt% is the mass percentage of each element in the neodymium iron boron magnet material ii.

In the present invention, the content range of B is preferably 0.94 to 1.02 wt%, for example, 0.99 wt% or 1 wt%, where wt% is the mass percentage of each element in the neodymium iron boron magnet material ii.

In the present invention, the Cu content is preferably in the range of 0 to 0.3 wt%, for example, 0.02 wt%, 0.05 wt%, 0.11 wt%, 0.15 wt%, or 0.3 wt%; more preferably 0.02-0.15 wt%, wherein the wt% is the mass percentage of each element in the neodymium iron boron magnet material II.

In the present invention, the content of Ga is preferably in the range of 0 to 0.3 wt%, for example, 0.05 wt%, 0.15 wt%, 0.2 wt%, or 0.21 wt%; more preferably 0.05-0.15 wt%, wherein the wt% is the mass percentage of each element in the neodymium iron boron magnet material II.

In the present invention, the content of Al is in the range of 0 to 0.3 wt%, more preferably 0 to 0.1 wt%, such as 0.02 wt%, 0.04 wt% or 0.08 wt%; more preferably 0 to 0.04 wt%, wherein wt% is the mass percentage of each element in the neodymium iron boron magnet material II. When the content of Al is 0-0.1 wt%, the content of Al can be in the content range of impurity Al introduced in the process of preparing the neodymium iron boron material, or can be additionally added Al. When the content of Al is 0-0.04 wt%, the range is the content range of impurity Al introduced in the process of preparing the neodymium iron boron material.

When X includes Zr, the content of Zr is preferably in the range of 0.02 to 0.3 wt%, for example, 0.2 wt%, and wt% is the mass percentage of each element in the neodymium iron boron magnet material ii.

When X includes Ti, the content of Ti is preferably in a range of 0 to 0.2 wt%, and is not 0, for example, 0.02 wt%, where wt% is the mass percentage of each element in the neodymium iron boron magnet material ii.

When X includes Nb, the content of Nb is preferably in the range of 0 to 0.4 wt%, and is not 0, for example, 0.03 wt%, 0.1 wt%, and wt% is the mass percentage of each element in the neodymium iron boron magnet material ii.

When X includes Hf, the content of Hf is preferably in the range of 0 to 0.1 wt%, and is not 0, for example, 0.03 wt% or 0.05 wt%, wt% being the mass percentage of each element in the neodymium iron boron magnet material ii.

In the invention, the neodymium iron boron magnet material II can also comprise Mn. The content range of Mn is less than or equal to 0.035 wt%, and more preferably less than or equal to 0.0175 wt%.

In the present invention, preferably, the neodymium iron boron magnet material ii includes:

nd: 19.3 to 32 wt%; ho: 0 to 10 wt% and not 0; gd: 0 to 5 wt% and not 0; b: 0.94-1.02 wt%; cu: 0-0.3 wt%; ga: 0-0.3 wt%; al: 0 to 0.1 wt%; zr: 0.02-0.3 wt%;

the balance being Fe and unavoidable impurities.

nd: 19.3 to 32 wt%; ho: 0 to 10 wt% and not 0; gd: 0 to 5 wt% and not 0; b: 0.94-1.02 wt%; cu: 0-0.3 wt%; ga: 0-0.3 wt%; al: 0 to 0.1 wt%; hf: 0 to 0.1 wt% and not 0; nb: 0 to 0.4 wt% and not 0;

the balance being Fe and unavoidable impurities.

The invention also provides an application of the neodymium iron boron magnet material in preparing magnetic steel, wherein the neodymium iron boron magnet material is the neodymium iron boron magnet material I and/or the neodymium iron boron magnet material II. When diffused with Dy, the magnetic steels may be 35UH and 38 UH. When diffused with Tb, the magnetic steels may be 35EH and 38 EH.

In the invention, a lubricant and the like are generally added in the preparation process, and the content of the introduced carbon impurities is conventional in the field and is generally 0-0.12 wt%.

On the basis of the common knowledge in the field, the above preferred conditions can be combined randomly to obtain the preferred embodiments of the invention.

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

The positive progress effects of the invention are as follows:

1) the Br of the neodymium iron boron magnet material II can be 12.45-13.9 kGs, and the Hcj is 14.55-19.89 kOe;

2) at normal temperature, Br of the neodymium iron boron magnet material I is 12.4-13.83 kGs, and Hcj is 25.2-32.21 kOe; increasing the increment of Hcj after diffusion to 8.1-12.32 kOe; the grain boundary continuity is 96.5-97.2%;

3) based on the formula components of the application, the high-temperature resistant performance is good due to the matching of all elements: the open-circuit magnetic loss of the neodymium iron boron magnet material I is 0.1-3.56%, and the absolute value of the Br temperature coefficient is 0.079-0.1%; the absolute value of the Hcj temperature coefficient is 0.381-0.473%.

Drawings

Fig. 1 is an SEM photograph of the pre-diffusion neodymium iron boron magnet material (ii) prepared in example 1.

Fig. 2 is an SEM photograph of the pre-diffusion neodymium iron boron magnet material (ii) prepared in comparative example 8.

Fig. 3 is an SEM photograph of the diffused ndfeb magnet material (i) obtained in example 1.

Fig. 4 is an EPMA photograph of Tb diffusion in the neodymium-iron-boron magnet material (i) after diffusion obtained in example 1.

Detailed Description

The invention is further illustrated by the following examples, which are not intended to limit the scope of the invention. The experimental methods without specifying specific conditions in the following examples were selected according to the conventional methods and conditions, or according to the commercial instructions.

TABLE 1 formulation and content (wt%) of raw material composition of NdFeB magnet Material II

Note: "/" means that the element is not included.

TABLE 2 formulation and content (wt%) of raw material composition of NdFeB magnet Material I

Note: "/" means that the element is not included.

The preparation method of the neodymium iron boron magnet material I, II is as follows:

in the examples and comparative examples of the present invention, the content of the introduced carbon impurities is conventional in the art, i.e., 0 to 0.12 wt%.

(1) Smelting and casting processes: the prepared raw materials (or the raw materials shown in Table 1) except for R2 were placed in a crucible of alumina according to the formulation shown in tables 1 to 2, and vacuum melting was carried out in a high-frequency vacuum melting furnace under a vacuum of 0.05Pa and at 1500 ℃. Introducing argon into the intermediate frequency vacuum induction rapid hardening melt-spun furnace, casting, and rapidly cooling the alloy to obtain an alloy sheet.

(2) Hydrogen crushing powder preparation process: and (3) vacuumizing the hydrogen breaking furnace in which the quenching alloy is placed at room temperature, introducing hydrogen with the purity of 99.9% into the hydrogen breaking furnace, maintaining the pressure of the hydrogen at 90kPa, fully absorbing the hydrogen, vacuumizing while heating, fully dehydrogenating, cooling, and taking out the powder after hydrogen breaking and crushing. Wherein the temperature for hydrogen absorption is room temperature, and the temperature for dehydrogenation is 550 ℃.

(3) And (3) airflow milling powder preparation process: the powder after hydrogen crushing is subjected to jet milling under a nitrogen atmosphere and under the condition that the pressure of a crushing chamber is 0.65MPa (the efficiency of jet milling powder can be different according to equipment, and can be 200kg/h for example), and fine powder is obtained.

(4) And (3) forming: and pressing and molding the powder subjected to the air flow milling in the magnetic field intensity of more than 1.5T.

(5) And (3) sintering: and (3) carrying the molded bodies to a sintering furnace for sintering, and sintering for 2-8h at the temperature of 1030-1090 ℃ under the vacuum condition of less than 0.5Pa to obtain the neodymium iron boron magnet material II.

(6) And (3) a grain boundary diffusion process: and (2) after the surface of the neodymium iron boron magnet material II is purified, coating R2 (such as Tb alloy or fluoride, Dy alloy or fluoride and one or more of DyCuGa and TbCuGa) on the surface of the sintered body, diffusing at 900 ℃ for 24h, cooling to room temperature, and performing heat treatment at 480-510 ℃ for 3h to obtain the neodymium iron boron magnet material I.

Effects of the embodiment

The neodymium iron boron magnet material I and the neodymium iron boron magnet material II in the examples 1 to 11 and the comparative examples 1 to 8 are respectively taken, the magnetic property and the components are measured, and the phase composition of the magnet is observed by adopting EPMA-1720.

(1) Each component of the neodymium iron boron magnet material i and the neodymium iron boron magnet material ii was measured using a high frequency inductively coupled plasma emission spectrometer (ICP-OES, Icap 6300). The following table 3 shows the results of component detection.

TABLE 3 composition and content (wt%) of NdFeB magnet Material II

Note: "/" means that the element is not included.

TABLE 4 composition and content (wt%) of NdFeB magnet Material I

Note: "/" means that the element is not included.

(2) Evaluation of magnetic Properties: the neodymium iron boron magnet materials I (namely after diffusion) and II (namely before diffusion) are subjected to magnetic property detection by using a PFM-14 magnetic property measuring instrument of Hirst company in UK; the following Table 5 shows the results of magnetic property measurements.

(3) Testing the high-temperature performance of the neodymium iron boron magnet material I: the formula for calculating the temperature coefficient is:

and

the calculation results are shown in table 5.

(4) The data calculation method of the open circuit magnetic loss comprises the following steps:

firstly measuring the magnetic flux M1 (a fluxmeter HT707) of the neodymium iron boron magnet material I product at normal temperature, then heating the product in an oven to the set temperature of 140 ℃, preserving the heat for 60min, and measuring the magnetic flux M2 when cooling to normal temperature, wherein the calculation formula of the open-circuit magnetic loss at high temperature is as follows:

wherein the normal temperature is 20 ℃.

(5) Determination of microstructure: the test results are shown in Table 5, wherein R_40-85Ho_0.1-10Gd_0.1-5Cu_0.1-2.0X_3-7The new phase (in the grain boundary epitaxial layer structure indicated by the arrow in FIG. 1) was obtained according to the FE-EPMA test. As can be seen from fig. 1, the ndfeb magnet material before diffusion in example 1 forms a grain boundary epitaxial layer structure favorable for diffusion, and the continuity of the grain boundary is high.

The calculation method of the grain boundary continuity refers to a ratio of a length occupied by phases (for example, neodymium-rich phase and phase equal to each other in the grain boundary epitaxial layer) other than the voids in the grain boundary to the total grain boundary length.

TABLE 5 test results for NdFeB magnet materials

In the above table, "the detection result at the normal temperature of 20 ℃ before diffusion" refers to the performance of the ndfeb magnet material ii (i.e., "before diffusion"), and the others refer to the performance of the ndfeb magnet material i after diffusion.

Fig. 2 shows that before diffusion, the ndfeb permanent magnet material does not form a grain boundary epitaxial layer structure beneficial to diffusion, which results in poor continuity of the grain boundary.

It is shown in fig. 4 that Tb is dispersed mainly uniformly in the neodymium-rich phase and the primary phase shell structure after diffusion.

TABLE 6

Sampling points in FIG. 3	Phases of each	Ho(wt％)	Gd(wt％)	PrNd(wt％)	Others (wt%)
						1	Phase rich in neodymium	0.73	0.02	81.47	17.78
2	Grain boundary epitaxial layer	5.54	0.86	53.22	40.38
						3	Main phase	7.55	1.02	20.54	70.89

Note: taking sample point 1 as an example, which belongs to a neodymium-rich phase, in a sampling range of a small region, the Ho content is 0.73 wt%, the Gd content is 0.02 wt%, the PrNd content is 81.47 wt%, and the other element content is 17.78 wt%, wherein the percentages are weight percentages of the content of each element in the sampling range respectively accounting for the content of all elements.

As can be seen from fig. 3 and table 6, in the neodymium-iron-boron magnet material diffused in example 1, Ho and Gd are mainly concentrated in the main phase (dark gray region) of the substrate, and then in the grain boundary epitaxial layer (i.e. the boundary where the main phase and the neodymium-rich phase intersect, which may also be called two-grain boundary), and in the middle diagram of the neodymium-rich phase, the distribution of Ho and Gd elements is less in the gray region.

The components of the neodymium-rich phase, the main phase and the grain boundary side epitaxial layer are tested by EDS in an SEM electron microscope, in the structure with low Co and Ho, the area ratio of (the neodymium-rich phase and the grain boundary epitaxial layer)/the total grain boundary phase) is calculated by pictures to be more than 96.5 percent and is more than 95 percent of the conventional Co-containing (generally more than 1 percent) magnet neodymium-rich phase in the total grain boundary phase, namely the ratio of the neodymium-rich phase to the grain boundary epitaxial layer is increased, the continuity of the grain boundary is increased, and the coercive force is obviously improved.

1) As can be seen from fig. 1 and table 5, a new phase is formed in the grain boundary epitaxial layer structure of the ndfeb magnet material before diffusion, and the continuity of the grain boundary is improved, which is beneficial to the diffusion of Dy and/or Tb grain boundaries, so that Hcj after diffusion is significantly improved, and the open-circuit magnetic loss is small; the elements in the formula are matched, and the high-temperature resistance is good (examples 1-11).

2) Based on the formula of the application, Ho is removed, TRE is unchanged, the coercive force is not obviously improved, the magnetic loss is large at high temperature, and the grain boundary continuity is low (comparative example 1).

3) Based on the formula of the application, after the X element is removed, the coercive force is not obviously improved, the magnetic loss is large at high temperature, and the continuity of the grain boundary is low (comparative example 2).

4) Based on the formula of the application, the content of Ho exceeds 10 wt%, the remanence is obviously reduced, the coercive force is not obviously improved, the magnetic loss is not obvious, and the continuity of grain boundaries is relatively low (comparative example 3).

5) Based on the formulation of the present application, Al exceeds 0.5 wt% except for Ga, and since excessive addition of Al deteriorates remanence and curie temperature, magnetic loss is relatively high and grain boundary continuity is low (comparative example 4).

6) Based on the formula of the present application, Ga exceeds 0.35 wt%, coercivity is not significantly improved, magnetic loss is not significant, and grain boundary continuity is relatively low (comparative example 5).

7) Based on the formula of the alloy, the TRE content is changed, Al is added, Ga and X are not added, the remanence is low, the high-temperature resistance is poor, the magnetic loss is very obvious, and the grain boundary continuity is relatively low (comparative example 6).

8) Based on the formula of the application, Ho is removed, the total TRE is kept unchanged, the coercive force is not obviously improved, the high-temperature resistance is still poor, the magnetic loss is obvious, and the grain boundary continuity is lower (comparative example 7).

9) Based on the formula of the application, Ho, X, Cu and Ga are not added, the total TRE is unchanged, the coercive force is not obviously improved, the high-temperature resistance is poor, the magnetic loss is large, and the grain boundary continuity is low (comparative example 8).

Claims

1. An ndfeb magnet material i, characterized in that it comprises:

R：29.5～32.5wt％；

the R1 comprises Nd, Ho and Gd, and does not comprise Dy and/or Tb; the content of Ho in the R1 is 0-10 wt% and is not 0;

r2 includes Dy and/or Tb;

Co：0～0.5wt％；

B：0.9～1.05wt％；

cu: 0 to 0.35 wt% and not 0;

ga: 0 to 0.35 wt% and not 0;

Al：0～0.5wt％；

X：0.05～0.45wt％；

x comprises one or more of Ti, Nb, Zr, Hf, V, Mo, W, Ta and Cr;

more than 95% Ho distribution in the R1 is distributed in the Nd₂Fe_l4B crystal grains and the grain boundary epitaxial layer, wherein more than 95% of R2 is distributed in the shell layer and the neodymium-rich phase;

the grain boundary continuity of the neodymium iron boron magnet material is more than 96.5 percent

The grain boundary epitaxial layer contains R_40-85Ho_0.1-10Gd_0.1-5Cu_0.1-2.0X_3-7The phase structure of (1).

2. The neodymium-iron-boron magnet material I as claimed in claim 1, wherein the grain boundary continuity is more than 96.6%;

and/or the content range of R is 29.9-31.8 wt%, and the wt% is the mass percentage of each element in the neodymium iron boron magnet material I;

and/or the Nd content in the R1 is 19.3-32 wt%, and the wt% is the mass percentage of each element in the neodymium iron boron magnet material I;

and/or the Ho content in the R1 is 7.5 wt%, 5.5 wt%, 4 wt%, 2.5 wt%, 0.5 wt%, 6.7 wt%, 1 wt%, 1.2 wt% or 8.4 wt%, and the wt% is the mass percentage of each element in the neodymium iron boron magnet material I;

and/or the Gd content in the R1 is 0-5 wt% and is not 0; the weight percent is the mass percentage of each element in the neodymium iron boron magnet material I;

and/or the total mass of Gd and Ho added does not exceed 10 wt%;

and/or the R1 does not contain heavy rare earth metals except Ho and Gd;

and/or, the R1 also comprises Pr and/or Sm;

and/or the content range of the R2 is 0.2-0.85 wt%, and the wt% is the mass percentage of each element in the neodymium iron boron magnet material I;

and/or the content range of Co is 0-0.47 wt%, and the wt% is the mass percentage of each element in the neodymium iron boron magnet material I;

and/or the content range of B is 0.94-1.02 wt%, and the wt% is the mass percentage of each element in the neodymium iron boron magnet material I;

and/or the content range of the Cu is 0-0.3 wt%, and the wt% is the mass percentage of each element in the neodymium iron boron magnet material I;

and/or the content range of Ga is 0-0.3 wt%, and the wt% is the mass percentage of each element in the neodymium iron boron magnet material I;

and/or the content range of the Al is 0-0.3 wt%, and the wt% is the mass percentage of each element in the neodymium iron boron magnet material I;

and/or the content of X is 0.05-0.3 wt% or 0.33 wt%;

and/or the X is one or more of Ti, Nb, Zr and Hf.

3. The neodymium-iron-boron magnet material I as claimed in claim 1, wherein the grain boundary continuity is 96.8%, 96.9%, 96.66%, 97.1%, 97.2%, 96.7%;

and/or the content range of R is 29.95 wt%, 30.2 wt%, 30.5 wt% or 31.5 wt%, and wt% is the mass percentage of each element in the neodymium iron boron magnet material I;

and/or the Nd content in the R1 is 31 wt%, 20 wt%, 21 wt% or 26 wt%, and the wt% is the mass percentage of each element in the neodymium iron boron magnet material I;

and/or the Ho content in the R1 is 0.5-4 wt% or 5.5-8.5 wt%, and the wt% is the mass percentage of each element in the neodymium iron boron magnet material I;

and/or the Gd content in the R1 is 0-3 wt% and is not 0, and the wt% is the mass percentage of each element in the neodymium iron boron magnet material I;

and/or the content range of the R2 is 0.5 wt%, 0.7 wt% or 0.8 wt%, and the wt% is the mass percentage of each element in the neodymium iron boron magnet material I;

and/or the content range of the Co is 0.22 wt% or 0.35 wt%, and the wt% is the mass percentage of each element in the neodymium iron boron magnet material I;

and/or the content range of B is 0.99 wt% or 1 wt%, and the wt% is the mass percentage of each element in the neodymium iron boron magnet material I;

and/or the Cu content ranges from 0.02 wt%, 0.05 wt%, 0.11 wt%, 0.15 wt%, or 0.3 wt%; the weight percent is the mass percentage of each element in the neodymium iron boron magnet material I;

and/or the Ga content ranges from 0.05 wt%, 0.15 wt%, 0.2 wt% or 0.21 wt%; the weight percent is the mass percentage of each element in the neodymium iron boron magnet material I;

and/or the content range of the Al is 0-0.1 wt%, and the wt% is the mass percentage of each element in the neodymium iron boron magnet material I;

and/or the content of X is 0.2 wt%, 0.3 wt% or 0.07 wt%.

4. The ndfeb magnet material i according to claim 1, wherein the Gd content in R1 is 1 wt%, 0.5 wt%, 0.4 wt%, 3 wt%, 0.2 wt%, or 0.7 wt%, wt% being the mass percentage of each element in the ndfeb magnet material i;

and/or the content range of the Cu is 0.02-0.15 wt%, and the wt% is the mass percentage of each element in the neodymium iron boron magnet material I;

and/or the content range of Ga is 0.05-0.15 wt%, and the wt% is the mass percentage of each element in the neodymium iron boron magnet material I;

and/or the Al content ranges from 0.02 wt%, 0.04 wt% or 0.08 wt%; more preferably 0-0.04 wt%, wherein wt% is the mass percentage of each element in the neodymium iron boron magnet material I.

5. The ndfeb magnet material i according to claim 1, wherein the Al content is in the range of 0 to 0.04 wt%, and wt% is the mass percentage of each element in the ndfeb magnet material i.

6. Neodymium iron boron magnet material I according to any one of claims 1 to 5, characterized in that when R1 contains Pr, Pr is added in the form of PrNd, or in the form of a mixture of pure Pr and Nd, or in combination of PrNd, pure Pr and Nd;

and/or when the R1 contains Sm, the content of the Sm is 0-3 wt%;

and/or, when R2 comprises Dy, the Dy is contained in the range of 0.2-0.8 wt%;

and/or, when the R2 comprises Tb, the content of Tb is in the range of 0.05-0.7 wt%;

and/or when R2 is a mixture of Dy and Tb, the weight ratio of Dy to Tb is 1: 99-99: 1;

and/or, when X comprises Zr, the content of Zr is in the range of 0.02-0.3 wt%;

and/or, when X comprises Ti, the content of Ti is in the range of 0-0.2 wt%;

and/or, when X comprises Nb, the content of Nb is in the range of 0-0.4 wt%;

and/or, when X comprises Hf, the content of the Hf is in a range of 0-0.1 wt%;

and/or when X comprises Ti and Nb, the weight ratio of Ti to Nb is 1: 99-99: 1;

and/or when X comprises Hf and Zr, the weight ratio of Hf to Zr is 1: 99-99: 1;

and/or when X comprises Hf and Nb, the weight ratio of Hf to Nb is 1: 99-99: 1;

and/or the neodymium iron boron magnet material I also comprises Mn.

7. The ndfeb magnet material i as claimed in claim 6, wherein when R1 contains Pr, the content of Pr is 0-16 wt% and is not 0, wt% being the mass percentage of each element in the ndfeb magnet material i;

and/or, when said R1 comprises Sm, said Sm is present in an amount of 0.7 wt%;

and/or, when R2 includes Dy, the Dy is present in an amount ranging from 0.2 wt%, 0.4 wt%, or 0.5 wt%;

and/or, when said R2 includes Tb, said Tb is present in an amount ranging from 0.5 wt%, 0.3 wt% or 0.4 wt%;

and/or, when R2 is a mixture of Dy and Tb, the weight ratio of Dy to Tb is 1:1, 3:2, 16:1 or 2: 3;

and/or, when X comprises Zr, said Zr content ranges from 0.2 wt%;

and/or, when X comprises Ti, said Ti is present in an amount ranging from 0.02 wt%;

and/or, when X comprises Nb, the Nb content ranges from 0.03 wt% or 0.1 wt%;

and/or, when X comprises Hf, the amount of Hf ranges from 0.03 wt% or 0.05 wt%;

and/or, when X comprises Ti and Nb, the weight ratio of Ti to Nb is 2:1 or 2: 3;

and/or, when X comprises Hf and Zr, the weight ratio of Hf to Zr is 1:10 or 5: 2;

and/or, when X comprises Hf and Nb, the weight ratio of Hf to Nb is 1: 8;

and/or when the neodymium iron boron magnet material I further comprises Mn, the content range of Mn is less than or equal to 0.035 wt%.

8. The ndfeb magnet material i according to claim 7, wherein when R1 contains Pr, the content of Pr is 0.2 to 7 wt%, wt% being the mass percentage of each element in the ndfeb magnet material i;

and/or when the neodymium iron boron magnet material I further comprises Mn, the content range of Mn is less than or equal to 0.0175 wt%.

9. The ndfeb magnet material i according to claim 1, wherein the ndfeb magnet material i comprises:

10. The ndfeb magnet material i according to claim 1, wherein the ndfeb magnet material i comprises:

11. A method for preparing the neodymium-iron-boron magnet material i as claimed in any one of claims 1 to 10, which is characterized by adopting a raw material composition of the neodymium-iron-boron magnet material i; wherein:

(1) the raw material composition of the neodymium iron boron magnet material I comprises the following components:

R：29.5～32.5wt％；

r2 includes Dy and/or Tb;

Co：0～0.5wt％；

B：0.9～1.05wt％；

cu: 0 to 0.35 wt% and not 0;

ga: 0 to 0.35 wt% and not 0;

Al：0～0.5wt％；

X：0.05～0.45wt％；

x comprises one or more of Ti, Nb, Zr, Hf, V, Mo, W, Ta and Cr;

Fe：66～70wt％；

the weight percent is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material I;

(2) the preparation method is a diffusion preparation method, wherein the R1 element is added in a smelting step, and the R2 element is added in a grain boundary diffusion step.

12. The method for preparing the neodymium-iron-boron magnet material I as claimed in claim 11, wherein the content of R is 29.9-32 wt%, and the wt% is the mass percentage of each element in the raw material composition of the neodymium-iron-boron magnet material I;

and/or the Nd content in the R1 is 19.3-32 wt%, and the wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material I;

and/or the Ho content in the R1 is 0.5-4 wt% or 5.5-8.5 wt%, and the wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material I;

and/or the Gd content in the R1 is 0-5 wt% and is not 0; the weight percent is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material I;

and/or, in the R1, the total addition mass of Gd and Ho is not more than 10 wt%;

and/or the R1 does not contain heavy rare earth metals except Ho and Gd;

and/or, the R1 also comprises Pr and/or Sm;

and/or the content range of the R2 is 0.2-0.85 wt%, and the wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material I;

and/or the content range of Co is 0-0.47 wt%, and the wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material I;

and/or the content range of B is 0.94-1.02 wt%, and the wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material I;

and/or the content range of the Cu is 0-0.3 wt%, and the wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material I;

and/or the content range of Ga is 0-0.3 wt%, and the wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material I;

and/or the content range of the Al is 0-0.3 wt%, and the wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material I;

and/or the content of X is 0.05-0.3 wt% or 0.33 wt%;

and/or the X is one or more of Ti, Nb, Zr and Hf.

13. The method for preparing the neodymium-iron-boron magnet material I as claimed in claim 11, wherein the content range of R is 29.95 wt%, 30.2 wt%, 30.5 wt%, 31.5 wt% or 31.8 wt%, and wt% is the mass percentage of each element in the raw material composition of the neodymium-iron-boron magnet material I;

and/or the Nd content in the R1 is 31 wt%, 20 wt%, 21 wt% or 26 wt%, and the wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material I;

and/or the Ho content in the R1 is 7.5 wt%, 5.5 wt%, 4 wt%, 2.5 wt%, 0.5 wt%, 6.7 wt%, 1 wt%, 1.2 wt% or 8.4 wt%, and the wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material I;

and/or the Gd content in the R1 is 0-3 wt% and is not 0, and the wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material I;

and/or the content range of the R2 is 0.5 wt%, 0.7 wt% or 0.8 wt%, and the wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material I;

and/or the content range of the Co is 0.22 wt% or 0.35 wt%, and the wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material I;

and/or the content range of B is 0.99 wt% or 1 wt%, and the wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material I;

and/or the Cu content ranges from 0.02 wt%, 0.05 wt%, 0.11 wt%, 0.15 wt%, or 0.3 wt%; the weight percent is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material I;

and/or the content range of Ga is 0.05-0.15 wt%, and the wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material I;

and/or the content range of the Al is 0-0.1 wt%, and the wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material I;

and/or the content of X is 0.2 wt%, 0.3 wt% or 0.07 wt%.

14. The method for preparing an ndfeb magnet material i according to claim 11, wherein the content of Gd in R1 is 1 wt%, 0.5 wt%, 0.4 wt%, 3 wt%, 0.2 wt%, or 0.7 wt%, and wt% is the mass percentage of each element in the raw material composition of the ndfeb magnet material i

And/or the content range of the Cu is 0.02-0.15 wt%, and the wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material I;

and/or the content range of Ga is 0.05 wt%, 0.15 wt%, 0.2 wt% or 0.21 wt%, and the wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material I;

and/or the content range of the Al is 0.02 wt%, 0.04 wt% or 0.08 wt%, and the wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material I.

15. The method for preparing the neodymium-iron-boron magnet material I as claimed in claim 11, wherein the content of Al is 0-0.04 wt%, and the wt% is the mass percentage of each element in the raw material composition of the neodymium-iron-boron magnet material I.

16. The method for preparing neodymium-iron-boron magnet material I according to any one of claims 11 to 15,

when the R1 contains Pr, the addition form of Pr is in the form of PrNd, or in the form of a pure mixture of Pr and Nd, or in the form of a combination of PrNd, pure mixture of Pr and Nd;

and/or when the R1 contains Sm, the content of the Sm is 0-3 wt%;

and/or, when R2 comprises Dy, the Dy is contained in the range of 0.2-0.8 wt%;

and/or, when X comprises Zr, the content of Zr is in the range of 0.02-0.3 wt%;

and/or, when X comprises Ti, the content range of Ti is 0-0.2 wt% and is not 0;

and/or, when X comprises Nb, the content of Nb is in the range of 0-0.4 wt% and is not 0;

and/or, when X comprises Hf, the content of the Hf is in the range of 0-0.1 wt% and is not 0;

and/or when X comprises Ti and Nb, the weight ratio of Ti to Nb is 1: 99-99: 1;

and/or when X comprises Hf and Zr, the weight ratio of Hf to Zr is 1: 99-99: 1;

and/or when X comprises Hf and Nb, the weight ratio of Hf to Nb is 1: 99-99: 1;

and/or the raw material composition of the neodymium iron boron magnet material I also comprises Mn.

17. The method for preparing neodymium-iron-boron magnet material I as claimed in claim 16,

when the R1 contains Pr, the content of Pr is 0-16 wt% and is not 0, and the wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material I;

and/or, when said R1 comprises Sm, said Sm is present in an amount of 0.7 wt%;

and/or, when X comprises Zr, said Zr content ranges from 0.2 wt%;

and/or, when X comprises Nb, the Nb content ranges from 0.03 wt%, 0.1 wt%;

and/or, when X comprises Hf, the amount of Hf ranges from 0.03 wt% or 0.05 wt%;

and/or, when X comprises Hf and Nb, the weight ratio of Hf to Nb is 1: 8;

and/or when the raw material composition of the neodymium iron boron magnet material I further comprises Mn, the content range of Mn is less than or equal to 0.035 wt%.

18. The method for preparing neodymium-iron-boron magnet material I according to claim 17,

when the R1 contains Pr, the content of Pr is 0.2-7 wt%, and the wt% is the mass percentage of each element in the raw material composition of the neodymium iron boron magnet material I;

and/or when the raw material composition of the neodymium iron boron magnet material I also comprises Mn, the content range of the Mn is less than or equal to 0.0175 wt%.

19. The method for preparing the neodymium-iron-boron magnet material I as claimed in claim 11, wherein the raw material composition of the neodymium-iron-boron magnet material I comprises:

20. The method for preparing the neodymium-iron-boron magnet material I as claimed in claim 11, wherein the raw material composition of the neodymium-iron-boron magnet material I comprises:

21. The method for preparing the neodymium-iron-boron magnet material I as claimed in any one of claims 11 to 20, wherein the preparation method comprises the following steps: the raw material composition of any one of claims 11 to 20, wherein elements except R2 in the raw material composition are smelted, pulverized, formed and sintered to obtain a sintered body, and then a mixture of the sintered body and the R2 is subjected to grain boundary diffusion.

22. The method for preparing an ndfeb magnet material i according to claim 21, wherein the grain boundary diffusion is followed by a heat treatment at a temperature of 450 to 600 ℃.

23. The method for preparing nd-fe-b magnet material i according to claim 22, wherein the temperature of the heat treatment is 480-510 ℃.

24. An application of neodymium iron boron magnet material in preparing magnetic steel is characterized in that the neodymium iron boron magnet material is the neodymium iron boron magnet material I as claimed in any one of claims 1-10.