Disclosure of Invention
The invention aims to overcome the technical problems that the curie temperature and the coercive force of a neodymium iron boron magnet in the prior art are improved by adding Co, and the Co faces the defect of high price, and provides a neodymium iron boron magnet material, a raw material composition, a preparation method and application. The magnet material has the advantages of high remanence, high coercivity and good high-temperature performance.
The invention relates to a raw material composition of a neodymium iron boron magnet material, which comprises the following components in percentage by mass: r: 28 to 33 wt%;
r is rare earth elements including R1 and R2, R1 is rare earth element added during smelting, and R1 includes Nd and Dy; the R2 is a rare earth element added during grain boundary diffusion, the R2 comprises Tb, and the content of R2 is 0.2-1 wt%;
m: less than or equal to 0.4 wt% and not less than 0 wt%, the species of M comprises one or more of Ti, Ni, V, Nb, Ta, Cr, Mo, W, Mn, Zr, Hf and Ag;
cu: less than or equal to 0.15 wt% and less than 0 wt%;
B:0.9~1.1wt%;
Fe:60wt%~70.88wt%;
the wt% is the mass percentage of each element content in the total mass of the raw material composition;
the raw material composition does not contain Co.
In the present invention, the amount of R in the raw material composition is preferably 29 to 31% by weight.
In the present invention, in the raw material composition, the content of Nd in R1 may be conventional in the art, and is preferably 28 to 32.5 wt%, with the percentage being mass percentage of the total mass of the raw material composition.
In the present invention, the content of Dy in R1 in the raw material composition is preferably 0.2 wt% or less, for example, 0.1 to 0.2 wt%.
In the present invention, the R1 may further include other rare earth elements conventional in the art, including, for example, one or more of Pr, Ho, Tb, Gd, and Y.
Wherein, when said R1 contains Pr, the addition form of Pr is 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, Pr: nd 25:75 or 20: 80; when the raw material composition is added in the form of a pure mixture of Pr and Nd or a combination of PrNd, pure mixture of Pr and Nd, the content of Pr is preferably 0.1 to 2 wt%, such as 0.1 wt%, 0.2 wt%, wherein the percentage is the mass percentage of the total mass of the raw material composition. The pure Pr or Nd in the present invention generally means a purity of more than 99.5%.
When the R1 contains Ho, the content of Ho is preferably 0.1-0.2 wt%, and the percentage is the mass percentage of each component in the total mass of the raw material composition.
When the R1 contains Gd, the content of Gd is preferably 0.1 to 0.2 wt%, and the percentage is the mass percentage of each component in the total mass of the raw material composition.
When the R1 contains Y, the content of Y is preferably 0.1-0.2 wt%, and the percentage is the mass percentage of each component in the total mass of the raw material composition.
In the invention, the content of the R2 is preferably 0.2 wt% to 0.8 wt%, and the percentage is the mass percentage of each component in the total mass of the raw material composition.
In the present invention, the content of Tb in R2 is preferably 0.2 wt% to 0.8 wt%, for example, 0.6 wt%.
In the invention, the R2 may further comprise one or more of Pr, Dy, Ho and Gd. The rare earth elements can form a shell layer for diffusing the rare earth elements by a grain boundary diffusion principle.
When R2 contains Pr, the content of Pr is preferably 0.2 wt% or less, and is not 0 wt%, for example 0.2 wt%, where wt% is the mass percentage of element in the raw material composition.
Wherein, when R2 contains Dy, the content of Dy is preferably 0.3 wt% or less, and not 0 wt%, for example 0.3 wt%, wt% being the mass percentage of elements in the raw material composition.
Wherein, when the R2 includes Ho, the content of Ho is preferably 0.15 wt% or less and not 0 wt%, wt% being the mass percentage of the element in the raw material composition.
Wherein, when the R2 includes Gd, the content of Gd is preferably 0.15 wt% or less and not 0 wt%, wt% being the mass percentage of the element in the raw material composition.
In the present invention, the content of M is preferably 0.1 wt% to 0.15 wt%, or 0.25 wt% to 0.4 wt%, for example 0.15 wt%, 0.25 wt%, 0.3 wt%, 0.35 wt%, 0.4 wt%.
In the present invention, the kind of M is preferably one or more of Ti, Zr, Nb, Ni, V, Ta, Cr, Mo, W, Mn, Hf and Ag.
Wherein, when the M includes Ti, the content of Ti is preferably 0.05 wt% to 0.3 wt%, for example, 0.05 wt%, 0.15 wt%, 0.3 wt%, and more preferably 0.1 wt% to 0.15 wt%.
Wherein, when said M contains Nb, the content of Nb is preferably 0.05 wt% to 0.15 wt%, such as 0.05 wt%, 0.15 wt%, more preferably 0.05 wt% to 0.1 wt%.
Wherein, the M preferably also comprises one or more of Bi, Sn, Zn, Ga, In, Au and Pb.
Wherein, when the M comprises Ga, the content of the Ga is preferably in the range of 0.1 to 0.3 wt%, such as 0.1 wt%, 0.15 wt%, 0.3 wt%, and the wt% is the mass percentage of the element in the raw material composition.
When the M element includes Ga, and Ga is 0.2 wt% or more and not 0.35 wt%, it is preferable that Ti + Nb in the composition of the M element is 0.07 wt% or less and not 0 wt%, for example, 0.05 wt%, and wt% is the mass percentage of the element in the raw material composition. In addition, when Ti + Nb is excessive, remanence may be reduced.
In the present invention, the raw material composition of the present application preferably further contains Al; the content thereof is preferably 0.15 wt% or less, but not 0 wt%, for example 0.15 wt%.
When the M comprises Ga and Ga is 0.01 wt% or less, Al + Ga + Cu may be 0.15 wt% or less and not 0 wt%, for example 0.12 wt%; preferably, Al + Ga + Cu is 0.11 wt% or less and not 0 wt%, for example 0.07 wt%, wt% being the mass percentage of the element in the raw material composition.
In the present invention, the Cu content is preferably 0.08 wt% or less but not 0 wt%, or 0.1 wt% to 0.15 wt%, for example 0.07 wt%, 0.15 wt%.
In the present invention, the content of B is preferably 0.9 to 1.1% by weight, more preferably 0.97 to 1.05% by weight.
In the present invention, the content of Fe is preferably 65.65 wt% to 70.88 wt%, for example 67.99 wt%, 68.19 wt%.
In the present invention, preferably, the raw material composition comprises:
r: 29-31 wt%; the R1 comprises Nd and Dy, wherein the Dy is used in an amount of 0.1-0.2 wt%; r2 comprises Tb, the dosage of Tb is 0.2 wt% -0.8 wt%;
B:0.9wt%~1.1wt%;
cu: 0.15 wt% or less but not 0 wt%;
ti: 0.3 wt% or less but not 0 wt%;
the balance of Fe and inevitable impurities;
wherein the percentage is the mass percentage of each element in the raw material composition.
In a preferred embodiment of the present invention, the raw material composition comprises the following components:
r: 30.6 wt%; wherein R1 is Nd and Dy, Nd is 29.90 wt%, Dy is 0.10 wt%; r2 is Tb, Tb is 0.60 wt%;
B:0.99wt%;
Cu:0.07wt%;
Ti:0.15wt%;
Fe:68.19wt%;
wherein the percentage is the mass percentage of each element in the raw material composition.
In the present invention, preferably, the raw material composition comprises:
r: 29-31 wt%; the R1 comprises Nd and Dy, wherein the Dy is used in an amount of 0.1-0.2 wt%; r2 comprises Tb, the dosage of Tb is 0.2 wt% -0.8 wt%;
B:0.9wt%~1.1wt%;
cu: 0.15 wt% or less but not 0 wt%;
nb: 0.3 wt% or less but not 0 wt%;
the balance of Fe and inevitable impurities;
wherein the percentage is the mass percentage of each element in the raw material composition.
In a preferred embodiment of the present invention, the raw material composition comprises the following components:
r: 30.6 wt%; wherein R1 is Nd and Dy, Nd is 29.90 wt%, Dy is 0.10 wt%, R2 is Tb, Tb is 0.60 wt%;
B:0.99wt%;
Cu:0.07wt%;
Nb:0.15wt%;
Fe:68.19wt%;
wherein the percentage is the mass percentage of each element in the raw material composition.
In the present invention, preferably, the raw material composition comprises:
r: 29-31 wt%; the R1 comprises Nd and Dy, wherein the Dy is used in an amount of 0.1-0.2 wt%; r2 comprises Tb, the dosage of Tb is 0.2 wt% -0.8 wt%;
B:0.9wt%~1.1wt%;
cu: 0.15 wt% or less but not 0 wt%;
nb: 0.3 wt% or less but not 0 wt%;
Ga:0.05wt%-0.3wt%;
the balance of Fe and inevitable impurities;
wherein the percentage is the mass percentage of each element in the raw material composition.
In a preferred embodiment of the present invention, the raw material composition comprises the following components:
r: 30.6 wt%; wherein R1 is Nd and Dy, Nd is 29.90 wt%, Dy is 0.10 wt%, R2 is Tb, Tb is 0.60 wt%;
B:0.99wt%;
Cu:0.07wt%;
Nb:0.05wt%;
Ga:0.3wt%;
Fe:67.99wt%;
wherein, the percentage is the mass percentage of each element in the raw material composition.
In another preferred embodiment of the present invention, the raw material composition comprises the following components:
r: 29 wt%; wherein R1 is Nd and Dy, Nd is 28.6 wt%, Dy is 0.10 wt%, R2 is Tb, Tb is 0.30 wt%;
B:1.01wt%;
Cu:0.07wt%;
Ti:0.15wt%;
Ga:0.15wt%;
Fe:69.62wt%;
wherein the percentage is the mass percentage of each element in the raw material composition.
In another preferred embodiment of the present invention, the raw material composition comprises the following components:
r: 31 wt%; wherein R1 is Nd and Dy, Nd is 30.4 wt%, Dy is 0.10 wt%, R2 is Tb, Tb is 0.50 wt%;
B:0.98wt%;
Cu:0.07wt%;
Ti:0.15wt%;
Ga:0.1wt%;
Fe:67.7wt%;
wherein the percentage is the mass percentage of each element in the raw material composition.
In another preferred embodiment of the present invention, the raw material composition comprises the following components:
r: 30.6 wt%; wherein R1 is Nd and Dy, Nd is 29.9 wt%, Dy is 0.10 wt%, R2 is Tb, Tb is 0.60 wt%;
B:0.99wt%;
Cu:0.07wt%;
Ti:0.05wt%;
Ga:0.1wt%;
Fe:68.19wt%;
wherein the percentage is the mass percentage of each element in the raw material composition.
In another preferred embodiment of the present invention, the raw material composition comprises the following components:
r: 30.6 wt%; wherein R1 is Nd and Dy, Nd is 29.90 wt%, Dy is 0.10 wt%, R2 is Tb, Tb is 0.60 wt%;
B:0.99wt%;
Cu:0.07wt%;
Ti:0.3wt%;
Ga:0.1wt%;
Fe:67.94wt%;
wherein the percentage is the mass percentage of each element in the raw material composition.
In another preferred embodiment of the present invention, the raw material composition comprises the following components:
r: 28 wt%; wherein R1 is Nd and Dy, Nd is 27.3 wt%, Dy is 0.10 wt%, R2 is Tb, Tb is 0.2 wt%;
B:1.1wt%;
Cu:0.07wt%;
Ti:0.15wt%;
Nb:0.05wt%;
Ga:0.15wt%;
Fe:70.88wt%;
wherein the percentage is the mass percentage of each element in the raw material composition.
In another preferred embodiment of the present invention, the raw material composition comprises the following components:
r: 33 wt%; wherein R1 is Nd, Dy and Pr, Nd is 31.7 wt%, Dy is 0.20 wt%, Pr is 0.1 wt%, R2 is Tb, Tb is 1 wt%;
B:0.9wt%;
Cu:0.15wt%;
Ti:0.15wt%;
Al:0.15wt%;
Fe:65.65wt%;
wherein the percentage is the mass percentage of each element in the raw material composition.
In another preferred embodiment of the present invention, the raw material composition comprises the following components:
r: 31 wt%; wherein R1 is Nd and Dy, Nd is 29.9 wt%, Dy is 0.10 wt%, R2 is Tb, Dy and Pr, wherein Tb is 0.5 wt%, Dy is 0.30 wt%, and Pr is 0.20 wt%;
B:0.97wt%;
Cu:0.07wt%;
Ti:0.15wt%;
Fe:67.81wt%;
wherein the percentage is the mass percentage of each element in the raw material composition.
The invention also provides a preparation method of the neodymium iron boron magnet material, 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 for R2 in the raw material composition of the neodymium iron boron magnet material 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.
The smelting operation and conditions can be conventional smelting processes in the field, and elements except for R2 in the neodymium iron boron magnet material are generally smelted and cast by adopting an ingot casting process and a rapid hardening sheet process to obtain alloy sheets.
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.
The temperature of the smelting can be 1300-1700 ℃, preferably 1450-1550 ℃, for example 1500 ℃.
The smelting equipment is generally a high-frequency vacuum smelting furnace and/or a medium-frequency vacuum smelting furnace, such as a medium-frequency vacuum induction rapid hardening melt-spinning 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 to 650 ℃, preferably 500 to 550 ℃. The pressure of the hydrogen absorption is generally 50 to 600kPa, for example 90 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 stream in the gas stream milled powder may be, for example, nitrogen. The time of the airflow milling powder can be 2-4 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.
Wherein, the sintering operation and conditions can be sintering process conventional in the field.
The sintering can be carried out in a vacuum degree of less than 5X 10 -1 Pa, and the like.
The sintering temperature can be 1000-1200 ℃, for example 1030-1090 ℃.
The sintering time can be 0.5-10 h, such as 2-5 h.
In the present invention, it is known to those skilled in the art that the R2 coating operation is generally included before the grain boundary diffusion.
Wherein said R2 is typically coated in the form of a fluoride or low melting point alloy, such as Tb fluoride. When Dy is further contained, Dy is preferably coated in the form of a fluoride of Dy. In addition, when Pr is further included, preferably, Pr is added in the form of a PrCu alloy.
When the R2 contains Pr and Pr participates in grain boundary diffusion in the form of a PrCu alloy, preferably, the addition timing of Cu in the preparation method is a grain boundary diffusion step, or is added at the same time in a smelting step and a grain boundary diffusion step; when the Cu is added during grain boundary diffusion, the content of the Cu is preferably 0.03-0.15 wt%, and the wt% is the mass percentage of elements in the raw material composition; wherein the percentage of Cu in PrCu is 0.1-17 wt%.
In the present invention, the operation and conditions of the grain boundary diffusion treatment may be a grain boundary diffusion process that is conventional in the art.
The temperature of the grain boundary diffusion can be 800-1000 ℃, such as 850 ℃.
The time of the grain boundary diffusion can be 5-20 h, such as 5-15 h.
After the grain boundary diffusion, low temperature tempering treatment is also performed as conventional in the art. The temperature of the low temperature tempering treatment is generally 460-560 ℃, and the time is generally 1-3 h.
The invention also provides the neodymium iron boron magnet material prepared by the preparation method.
The invention also provides a neodymium iron boron magnet material, R: 28 to 33 wt%; the R comprises R1 and R2, the R1 comprises Nd and Dy, the R2 comprises Tb; the content of R2 is 0.2 wt% -1 wt%;
B:0.9~1.1wt%;
cu: 0.15 wt% or less and not 0 wt%;
m: 0.35 wt% or less and not 0 wt%;
m comprises one or more of Ti, Ni, V, Nb, Ta, Cr, Mo, W, Mn, Zr, Hf, Zn and Ag;
Fe:60wt%~70.88wt%;
the wt% is the mass percentage of each element in the neodymium iron boron magnet material;
the neodymium iron boron magnet material does not contain Co;
the neodymium-iron-boron magnet material comprises Nd 2 Fe l4 B crystal grains and shell layer thereof, adjacent to the Nd 2 Fe l4 Two-grain boundaries and grain boundary trigones of B grains, in which the heavy rare earth element in R1 is mainly distributed in Nd 2 Fe l4 B, crystal grains, wherein R2 is mainly distributed in the shell layer, the two-particle grain boundary and the grain boundary triangular region, and the area percentage of the grain boundary triangular region is 1.5-3.5%; the grain boundary continuity of the neodymium iron boron magnet material is more than 96%; the mass ratio of C to O in the crystal boundary triangular region is 0.4-0.5%, and the mass ratio of C to O in the two-particle crystal boundary is more than 0.35%.
In the present invention, the heavy rare earth element in "R1 is mainly distributed in Nd 2 Fe l4 B grains "can be understood as that heavy rare earth elements in R1 caused by the conventional smelting sintering process in the art are mainly distributed (generally, more than 95%) in main phase grains, and are distributed in small amount in grain boundaries. "R2 is mainly distributed in the shell layer, the two-particle grain boundary and the grain boundary triangle" can be understood as that R2 mainly distributed (generally, more than 95%) in the shell layer of the main phase grains, the two-particle grain boundary and the grain boundary triangle caused by the grain boundary diffusion process in the prior artThe bounded triangular regions, too, have a small portion diffused into the main phase grains, for example at the outer edges of the main phase grains.
In the present invention, the calculation mode of the grain boundary continuity refers to the ratio of the length occupied by the phase other than the void in the grain boundary (for example, B-rich phase, rare earth oxide, rare earth carbide, etc.) to the total grain boundary length. If the continuity of the grain boundary exceeds 96%, the channel is called a continuous channel.
In the invention, the grain boundary triangular region generally refers to a place where three or more grain boundaries intersect, and a B-rich phase, a rare earth oxide, a rare earth carbide and a cavity are distributed. The calculation mode of the area ratio of the grain boundary triangular region refers to the ratio of the area of the grain boundary triangular region to the total area (grains + grain boundaries).
Wherein C, O element in rare earth oxide and rare earth carbide is introduced in a conventional manner in the field, generally introduced as impurities or introduced in an atmosphere, specifically, for example, in the process of jet milling and pressing, additives are introduced, and during sintering, the additives are removed by heating, but a small amount of C, O element residue is unavoidable; for another example, a small amount of O element is inevitably introduced by the atmosphere during the preparation process. In the application, the content of C, O in the finally obtained neodymium iron boron magnet material product is only below 1000 ppm and 1200ppm respectively through detection, and the product belongs to the conventionally acceptable impurity category in the field, so that the product element statistical table is not included.
In the scheme of the invention, Tb forms a covering layer through grain boundary diffusion, so that the coercivity is improved; dy can reduce the generation amount of alpha-Fe during smelting, and is beneficial to the improvement of the magnetic property of the product.
In the present invention, it is known to those skilled in the art that C, O elements are generally present in the form of rare earth carbides and rare earth oxides in the grain boundary phase, and thus "mass ratio of C and O in the grain boundary triangle" and "mass ratio of C and O in the two-grain boundary" correspond to the hetero-phase rare earth carbides and rare earth oxides, respectively.
Wherein the percentage in "mass ratio (%) of C and O in the two-particle grain boundary" is the ratio of the mass of C and O in the two-particle grain boundary to the total mass of all elements in the grain boundary, and the percentage in "mass ratio (%) of C and O in the triangular region of the grain boundary" is the ratio of the mass of C and O in the triangular region of the grain boundary to the total mass of all elements in the grain boundary.
In addition, according to the example that the difference between "the mass ratio of C and O in the grain boundary triangular region" minus "the mass ratio (%) of C and O in the two-grain boundary" is smaller than that in the comparative example, it can be concluded that the hetero-phase migrates from the grain boundary triangular region to the two-grain boundary, which explains the reason for the improvement of the grain boundary continuity from the mechanism. In the present invention, the area ratio of the grain boundary trigones is preferably 1.59% to 3.28%, for example, 1.59%, 1.88%, 2.34%, 2.36%, 2.38%, 2.45%, 2.54%, 2.62%, 2.68%, 3.28%, more preferably 1.59% to 2%.
In the present invention, the grain boundary continuity is preferably 97% or more, for example 97.01%, 97.20%, 98.50%, 98.00%, 98.10%, 98.22%, 98.41%, 98.36%, 98.80%, 99.50%, more preferably 98% or more.
In the present invention, the mass ratio of C to O in the two-particle grain boundary is preferably 0.37% to 0.4%.
In the two-particle grain boundary of the magnet material of the present invention, in addition to the two hetero phases of the rare earth oxide and the rare earth carbide, preferably, a new phase having a chemical composition R is detected in the two-particle grain boundary x Fe 100-x-y-z Cu y M z (ii) a Wherein R comprises one or more of Nd, Dy and Tb, M comprises one or more of Ti, Ni, V, Nb, Ta, Cr, Mo, W, Mn, Zr, Hf, Zn and Ag, x is 32-36, y is less than 0.1 but not 0, z is less than 0.15 but not 0; wherein x is preferably 32.5-35.5, y is preferably 0.02-0.1, and z is preferably 0.07-0.12.
In preferred embodiments of the present application, the structure of the novel phase is, for example, R 34.5 Fe 65.4 Cu 0.03 M 0.07 ,R 34.1 Fe 65.68 Cu 0.1 M 0.12 ,R 33.2 Fe 66.68 Cu 0.04 M 0.08 ,R 33.56 Fe 66.28 Cu 0.05 M 0.11 ,R 34.41 Fe 65.42 Cu 0.08 M 0.09 ,R 35.26 Fe 64.58 Cu 0.07 M 0.09 ,R 35.50 Fe 64.38 Cu 0.04 M 0.08 ,R 32.50 Fe 67.39 Cu 0.03 M 0.08 ,R 33.33 Fe 66.58 Cu 0.02 M 0.07 ,R 34.22 Fe 65.64 Cu 0.06 M 0.08 。
In the present invention, the chemical composition is R x Fe 100-x-y-z Cu y M z The ratio of the area of the new phase in the two-particle grain boundary to the total area of the two-particle grain boundary is preferably 0.8 to 3%, more preferably 0.81 to 2.64%.
The inventors speculate that the new phase is generated at the grain boundary of the two grains, so that the continuity of the grain boundary is further improved, and the performance of the magnet is improved.
In the invention, the amount of R in the NdFeB magnet material is preferably 29-31 wt%.
In the neodymium iron boron magnet material, the content of Nd in R can be conventional in the field, and is preferably 28-32.5 wt%, and the percentage is the mass percentage of the total mass of the neodymium iron boron magnet material.
In the present invention, in the neodymium iron boron magnet material, the content of Dy in R1 is preferably less than 0.2 wt%, for example, 0.1 to 0.2 wt%.
In the present invention, the R1 may further include other rare earth elements conventional in the art, including, for example, one or more of Pr, Ho, Tb, Gd, and Y.
Wherein, when said R1 contains Pr, the addition form of Pr is 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, Pr: 25 Nd: 75 or 20: 80; when the pure Pr and Nd are added in the form of a mixture or a combination of PrNd, pure Pr and Nd, the Pr content is preferably 0.1-2 wt%, such as 0.1 wt%, 0.2 wt%, wherein the percentage is the mass percentage of each component content in the total mass of the NdFeB magnet material.
When the R1 contains Ho, the content of Ho is preferably 0.1 to 0.2 wt%, and the percentage is the mass percentage of each component in the total mass of the neodymium iron boron magnet material.
When the R1 contains Gd, the content of Gd is preferably 0.1 to 0.2 wt%, and the percentage is the mass percentage of each component in the total mass of the neodymium iron boron magnet material.
When the R1 contains Y, the content of Y is preferably 0.1 to 0.2 wt%, and the percentage is the mass percentage of each component in the total mass of the neodymium iron boron magnet material.
In the invention, the content of the R2 is preferably 0.2 wt% to 0.8 wt%, and the percentage is the mass percentage of each component in the total mass of the neodymium iron boron magnet material.
In the present invention, the content of Tb in R2 is preferably 0.2 wt% to 0.8 wt%, for example, 0.6 wt%.
In the invention, the R2 may further comprise one or more of Pr, Dy, Ho and Gd. The rare earth elements can form a shell layer for diffusing the rare earth elements by a grain boundary diffusion principle.
When R2 contains Pr, the content of Pr is preferably 0.2 wt% or less, and is not 0 wt%, for example 0.2 wt%, where wt% is the mass percentage of the element in the neodymium iron boron magnet material.
Wherein, when R2 contains Dy, the content of Dy is preferably 0.3 wt% or less, and not 0 wt%, for example 0.3 wt%, wt% being the mass percentage of elements in the neodymium iron boron magnet material.
When the R2 includes Ho, the content of Ho is preferably 0.15 wt% or less and not 0 wt%, where wt% is a mass percentage of an element in the neodymium iron boron magnet material.
Wherein, when the R2 includes Gd, the content of Gd is preferably 0.15 wt% or less and not 0 wt%, wt% being the mass percentage of the element in the neodymium iron boron magnet material.
In the present invention, the content of M is preferably 0.1 wt% to 0.15 wt%, or 0.25 wt% to 0.4 wt%, for example 0.15 wt%, 0.25 wt%, 0.3 wt%, 0.35 wt%, 0.4 wt%.
In the present invention, the kind of M is preferably one or more of Ti, Zr, Nb, Ni, V, Ta, Cr, Mo, W, Mn, Hf and Ag.
Wherein, when the M includes Ti, the content of Ti is preferably 0.05 wt% to 0.3 wt%, for example, 0.05 wt%, 0.15 wt%, 0.3 wt%, and more preferably 0.1 wt% to 0.15 wt%.
Wherein, when the M contains Nb, the content of Nb is preferably 0.05 wt% to 0.15 wt%, for example 0.05 wt%, 0.15 wt%, and more preferably 0.05 wt% to 0.1 wt%.
Wherein, the M preferably also comprises one or more of Bi, Sn, Zn, Ga, In, Au and Pb.
Wherein, when the M includes Ga, the content of the Ga is preferably in the range of 0.1 to 0.3 wt%, such as 0.1 wt%, 0.15 wt%, 0.3 wt%.
When the M element includes Ga and Ga is 0.2 wt% or more and is not 0.35 wt%, it is preferable that Ti + Nb in the composition of the M element is 0.07 wt% or less and is not 0 wt%, for example, 0.05 wt%. In addition, when Ti + Nb is excessive, remanence may be reduced.
In the present invention, preferably, the neodymium iron boron magnet material further contains Al; the content thereof is preferably 0.15 wt% or less, but not 0 wt%, for example 0.15 wt%.
When the M comprises Ga and Ga is 0.01 wt% or less, Al + Ga + Cu may be 0.15 wt% or less and not 0 wt%, for example 0.12 wt%; preferably, Al + Ga + Cu is 0.11 wt% or less, and is not 0 wt%, for example 0.07 wt%.
In the present invention, the content of Cu is preferably 0.08 wt% or less but not 0 wt%, or 0.1 wt% to 0.15 wt%, for example 0.07 wt%, 0.15 wt%.
In the present invention, the content of B is preferably 0.9 wt% to 1.1 wt%, more preferably 0.97 wt% to 1.05 wt%.
In the present invention, the content of Fe is preferably 65.65 wt% to 70.88 wt%, for example 67.99 wt%, 68.19 wt%.
In the present invention, preferably, the neodymium iron boron magnet material includes:
r: 29-31 wt%; the R1 comprises Nd and Dy, wherein the Dy is used in an amount of 0.1-0.2 wt%; r2 comprises Tb, the dosage of Tb is 0.2 wt% -0.8 wt%;
B:0.9wt%~1.1wt%;
cu: 0.15 wt% or less but not 0 wt%;
ti: 0.3 wt% or less but not 0 wt%;
the balance of Fe and inevitable impurities;
wherein, the percentage is the mass percentage of each element in the neodymium iron boron magnet material.
In a preferred embodiment of the present invention, the ndfeb magnet material comprises the following components:
r: 30.6 wt%; wherein R1 is Nd and Dy, Nd is 29.90 wt%, Dy is 0.10 wt%; r2 is Tb, Tb is 0.60 wt%;
B:0.99wt%;
Cu:0.07wt%;
Ti:0.15wt%;
Fe:68.19wt%;
wherein the percentage is the mass percentage of each element in the neodymium iron boron magnet material;
the area percentage of the grain boundary triangular region is 2.34 percent; the grain boundary continuity of the neodymium iron boron magnet material is 98%; the mass ratio of C to O in the triangular region of the grain boundary is 0.45 percent, and the mass ratio of C to O in the two-particle grain boundary is 0.39 percent; detection of a New phase R in the two-particle grain boundary 34.5 Fe 65.4 Cu 0.03 M 0.07 The ratio of the area of the new phase in the two-particle grain boundaries to the total area of the two-particle grain boundaries was 2.35%.
In the present invention, preferably, the neodymium iron boron magnet material includes:
r: 29-31 wt%; the R1 comprises Nd and Dy, wherein the Dy is used in an amount of 0.1-0.2 wt%; r2 comprises Tb, the dosage of Tb is 0.2 wt% -0.8 wt%;
B:0.9wt%~1.1wt%;
cu: 0.15 wt% or less but not 0 wt%;
nb: 0.3 wt% or less but not 0 wt%;
the balance of Fe and inevitable impurities;
wherein, the percentage is the mass percentage of each element in the neodymium iron boron magnet material.
In a preferred embodiment of the present invention, the neodymium iron boron magnet material comprises the following components:
r: 30.6 wt%; wherein R1 is Nd and Dy, Nd is 29.90 wt%, Dy is 0.10 wt%, R2 is Tb, Tb is 0.60 wt%;
B:0.99wt%;
Cu:0.07wt%;
Nb:0.15wt%;
Fe:68.19wt%;
wherein the percentage is the mass percentage of each element in the neodymium iron boron magnet material;
the area percentage of the grain boundary triangular region is 2.36%; the grain boundary continuity of the neodymium iron boron magnet material is 98.41%; the mass ratio of C to O in the triangular region of the grain boundary is 0.41 percent, and the mass ratio of C to O in the two-particle grain boundary is 0.38 percent; detection of a New phase R in the two-particle grain boundary 35.26 Fe 64.58 Cu 0.07 M 0.09 The ratio of the area of the new phase in the two-particle grain boundaries to the total area of the two-particle grain boundaries was 1.12%.
In the present invention, preferably, the neodymium iron boron magnet material includes:
r: 29-31 wt%; the R1 comprises Nd and Dy, wherein the Dy accounts for 0.1-0.2 wt%; r2 comprises Tb, the dosage of Tb is 0.2 wt% -0.8 wt%;
B:0.9wt%~1.1wt%;
cu: 0.15 wt% or less but not 0 wt%;
nb: 0.3 wt% or less but not 0 wt%;
Ga:0.05wt%-0.3wt%;
the balance of Fe and inevitable impurities;
wherein, the percentage is the mass percentage of each element in the neodymium iron boron magnet material.
In a preferred embodiment of the present invention, the ndfeb magnet material comprises the following components:
r: 30.6 wt%; wherein R1 is Nd and Dy, Nd is 29.90 wt%, Dy is 0.10 wt%, R2 is Tb, Tb is 0.60 wt%;
B:0.99wt%;
Cu:0.07wt%;
Nb:0.05wt%;
Ga:0.3wt%;
Fe:67.99wt%;
wherein the percentage is the mass percentage of each element in the neodymium iron boron magnet material;
the area percentage of the grain boundary triangular region is 2.45 percent; the grain boundary continuity of the neodymium iron boron magnet material is 98.80%; the mass ratio of C to O in the triangular region of the grain boundary was 0.45%, the mass ratio of C to O in the grain boundary of the secondary particle was 0.39%, and a new phase R was detected in the grain boundary of the secondary particle 35.50 Fe 64.38 Cu 0.04 M 0.08 The ratio of the area of the new phase in the two-particle grain boundaries to the total area of the two-particle grain boundaries was 2.03%.
In another preferred embodiment of the present invention, the ndfeb magnet material comprises the following components:
r: 29 wt%; wherein R1 is Nd and Dy, Nd is 28.6 wt%, Dy is 0.10 wt%, R2 is Tb, Tb is 0.30 wt%;
B:1.01wt%;
Cu:0.07wt%;
Ti:0.15wt%;
Ga:0.15wt%;
Fe:69.62wt%;
wherein the percentage is the mass percentage of each element in the neodymium iron boron magnet material;
the area percentage of the grain boundary triangular region is 1.88%; the grain boundary continuity of the neodymium iron boron magnet material is 97.20%; the mass ratio of C to O in the triangular region of the grain boundary is 0.44%, and the mass ratio of C to O in the two-particle grain boundary is 0.38%Detection of a novel phase R in the grain boundary of two grains 34.1 Fe 65.68 Cu 0.1 M 0.12 The ratio of the area of the new phase in the two-particle grain boundaries to the total area of the two-particle grain boundaries was 1.74%.
In another preferred embodiment of the present invention, the ndfeb magnet material comprises the following components:
r: 31 wt%; wherein R1 is Nd and Dy, Nd is 30.4 wt%, Dy is 0.10 wt%, R2 is Tb, Tb is 0.50 wt%;
B:0.98wt%;
Cu:0.07wt%;
Ti:0.15wt%;
Ga:0.1wt%;
Fe:67.7wt%;
wherein the percentage is the mass percentage of each element in the neodymium iron boron magnet material;
the area percentage of the grain boundary triangular region is 2.68 percent; the continuity of the grain boundary of the neodymium iron boron magnet material is 98.36%; the mass ratio of C to O in the triangular region of the grain boundary was 0.45%, the mass ratio of C to O in the grain boundary of the secondary particle was 0.39%, and a new phase R was detected in the grain boundary of the secondary particle 33.2 Fe 66.68 Cu 0.04 M 0.08 The ratio of the area of the new phase in the two-particle grain boundaries to the total area of the two-particle grain boundaries was 1.94%.
In another preferred embodiment of the present invention, the ndfeb magnet material comprises the following components:
r: 30.6 wt%; wherein R1 is Nd and Dy, Nd is 29.9 wt%, Dy is 0.10 wt%, R2 is Tb, Tb is 0.60 wt%;
B:0.99wt%;
Cu:0.07wt%;
Ti:0.05wt%;
Ga:0.1wt%;
Fe:68.19wt%;
wherein the percentage is the mass percentage of each element in the neodymium iron boron magnet material;
the area percentage of the grain boundary triangular region is 2.38%; grain boundary of the neodymium iron boron magnet materialThe continuity was 98.10%; the mass ratio of C to O in the triangular region of the grain boundary was 0.44%, the mass ratio of C to O in the grain boundary of the secondary particle was 0.4%, and a new phase R was detected in the grain boundary of the secondary particle 33.56 Fe 66.28 Cu 0.05 M 0.11 The ratio of the area of the new phase in the two-particle grain boundaries to the total area of the two-particle grain boundaries was 0.81%.
In another preferred embodiment of the present invention, the ndfeb magnet material comprises the following components:
r: 30.6 wt%; wherein R1 is Nd and Dy, Nd is 29.90 wt%, Dy is 0.10 wt%, R2 is Tb, Tb is 0.60 wt%;
B:0.99wt%;
Cu:0.07wt%;
Ti:0.3wt%;
Ga:0.1wt%;
Fe:67.94wt%;
wherein the percentage is the mass percentage of each element in the neodymium iron boron magnet material;
the area percentage of the grain boundary triangular region is 2.54 percent; the grain boundary continuity of the neodymium iron boron magnet material is 98.22%; the mass ratio of C to O in the triangular region of the grain boundary was 0.43%, the mass ratio of C to O in the grain boundary of the secondary particle was 0.4%, and a new phase R was detected in the grain boundary of the secondary particle 34.41 Fe 65.42 Cu 0.08 M 0.09 The ratio of the area of the new phase in the two-particle grain boundaries to the total area of the two-particle grain boundaries was 2.64%.
In another preferred embodiment of the present invention, the ndfeb magnet material comprises the following components:
r: 28 wt%; wherein R1 is Nd and Dy, Nd is 27.3 wt%, Dy is 0.10 wt%, R2 is Tb, Tb is 0.2 wt%;
B:1.1wt%;
Cu:0.07wt%;
Ti:0.15wt%;
Nb:0.05wt%;
Ga:0.15wt%;
Fe:70.88wt%;
wherein the percentage is the mass percentage of each element in the neodymium iron boron magnet material;
the area percentage of the grain boundary triangular region is 1.59 percent; the grain boundary continuity of the neodymium iron boron magnet material is 97.01%; the ratio of C to O by mass in the trigonal region of the grain boundary triple boundaries was 0.46%, the ratio of C to O by mass in the grain boundary double boundaries was 0.38%, and a new phase R was detected in the grain boundary double boundaries 32.50 Fe 67.39 Cu 0.03 M 0.08 The ratio of the area of the new phase in the two-particle grain boundaries to the total area of the two-particle grain boundaries was 1.06%.
In another preferred embodiment of the present invention, the ndfeb magnet material comprises the following components:
r: 33 wt%; wherein R1 is Nd, Dy and Pr, Nd is 31.7 wt%, Dy is 0.20 wt%, Pr is 0.1 wt%, R2 is Tb, Tb is 1 wt%;
B:0.9wt%;
Cu:0.15wt%;
Ti:0.15wt%;
Al:0.15wt%;
Fe:65.65wt%;
wherein the percentage is the mass percentage of each element in the neodymium iron boron magnet material;
the area percentage of the grain boundary triangular region is 3.28 percent; the grain boundary continuity of the neodymium iron boron magnet material is 99.50%; the ratio of C to O by mass in the triangular region of the grain boundary was 0.46%, the ratio of C to O by mass in the grain boundary of the secondary particle was 0.37%, and a new phase R was detected in the grain boundary of the secondary particle 33.33 Fe 66.58 Cu 0.02 M 0.07 The ratio of the area of the new phase in the two-particle grain boundaries to the total area of the two-particle grain boundaries was 1.58%.
In another preferred embodiment of the present invention, the ndfeb magnet material comprises the following components:
r: 31 wt%; wherein R1 is Nd and Dy, Nd is 29.9 wt%, Dy is 0.10 wt%, R2 is Tb, Dy and Pr, wherein Tb is 0.5 wt%, Dy is 0.30 wt%, and Pr is 0.20 wt%;
B:0.97wt%;
Cu:0.07wt%;
Ti:0.15wt%;
Fe:67.81wt%;
wherein the percentage is the mass percentage of each element in the neodymium iron boron magnet material;
the area percentage of the grain boundary triangular region is 2.62 percent; the continuity of the grain boundary of the neodymium iron boron magnet material is 98.50%; the mass ratio of C to O in the triangular region of the grain boundary was 0.48%, the mass ratio of C to O in the grain boundary of the secondary particle was 0.39%, and a new phase R was detected in the grain boundary of the secondary particle 34.22 Fe 65.64 Cu 0.06 M 0.08 The ratio of the area of the new phase in the two-particle grain boundaries to the total area of the two-particle grain boundaries was 1.87%.
The neodymium iron boron magnet material provided by the invention adopts a Co-free scheme, simultaneously reasonably controls the total rare earth content TRE and the content range of Cu and M (Ti, Nb and the like), and more impurity phases are distributed in two grain boundaries instead of being agglomerated in a grain boundary triangular area, so that the continuity of the grain boundaries is improved, the area of the grain boundary triangular area is reduced, higher density is beneficial to obtaining, and the residual magnetism Br of the magnet is improved; this also promotes the Tb to be uniformly distributed in the grain boundary and the main phase shell layer, and improves the coercive force Hcj of the magnet.
The invention also provides application of the neodymium iron boron magnet material in preparation of magnetic steel.
Wherein, the magnetic steel is preferably 54SH, 54UH and 56SH high-performance magnetic steel.
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 magnet material has excellent magnet performance, wherein Br is more than or equal to 14.5kGs, and Hcj is more than or equal to 24.5 kOe; the Br temperature coefficient is more than or equal to-0.106%/DEG C at the temperature of 20-120 ℃;
(2) the magnet material can be used for manufacturing 54SH, 54UH and 56SH high-performance magnetic steels, and the production cost is reduced because the magnet material does not contain Co.