Patent Application
20220336127
The present disclosure relates to a neodymium-iron-boron magnet material, a raw material composition and a preparation method therefor and a use thereof.
The neodymium-iron-boron (NdFeB) magnet material with Nd2Fe14B as the main component has high remanence (Br), coercivity and maximum energy product (BHmax) with great comprehensive magnetic properties, and is used in wind power generation, new energy vehicles, inverter household appliances and so on. The rare-earth components of the neodymium-iron-boron magnet materials in the prior art are usually dominated by neodymium with only a small amount of praseodymium. Although there are few reports in the prior art that replacing a portion of neodymium with praseodymium can improve the performance of the magnet material, the improvement is limited and still not significant. On the other hand, the neodymium-iron-boron magnet material with good coercivity and remanence properties in the prior art still need to rely on the addition of large amounts of heavy rare earth elements and the cost is relatively expensive.
The technical problem to be solved in the present disclosure is for overcoming the defect that the coercivity and remanence of the magnet material cannot be significantly improved after the neodymium is replaced with the praseodymium partially in the neodymium-iron-boron magnet material in the prior art, and it is still necessary to add larger amount of heavy rare earth elements to make the performance of magnet materials more excellent. A neodymium-iron-boron magnet material, a raw material composition and a preparation method therefor and a use thereof are provided. The neodymium-iron-boron magnet material of the present disclosure can still significantly improve the performance of the neodymium-iron-boron magnet material without adding heavy rare earth elements.
The present disclosure solves the above-mentioned technical problems through the following technical solutions.
The present disclosure provides a raw material composition of neodymium-iron-boron magnet material, which comprises the following components by mass percentage: 29.5-32.8% of R′, R′ comprises Pr and Nd; wherein, Pr≥17.15%;
the percentage is the mass percentage relative to the total mass of the raw material composition of neodymium-iron-boron magnet material.
In the present disclosure, the content of Pr is preferably 17.15-30%, for example 17.15%, 18.15%, 19.15%, 20.15%, 21.15%, 22.85%, 23.15%, 24.15%, 25.15%, 26.5%, 27.15% or 30%; more preferably 21-26.5%, the percentage is the mass percentage relative to the total mass of the raw material composition of neodymium-iron-boron magnet material.
In the present disclosure, the ratio of Nd to the total mass of R′ is preferably less than 0.5, more preferably 0.04-0.44, for example 0.04, 0.07, 0.12, 0.14, 0.15, 0.18, 0.2, 0.21, 0.22, 0.27, 0.36, 0.37, 0.38, 0.4, 0.41 or 0.44.
In the present disclosure, the content of Nd is preferably 15% or less, more preferably 1.5%-14%, for example 1.5%, 2.45%, 3.85%, 4.05%, 4.55%, 4.85%, 5.85%, 6.65%, 6.85%, 8.35%, 11.65%, 11.85%, 12.85% or 13.85%, the percentage refers to the mass percentage relative to the total mass of the raw material composition of neodymium-iron-boron magnet material.
In the present disclosure, preferably, R′ further comprises RH, RH refers to heavy rare earth elements, the kind of RH preferably comprises one or more of Dy, Tb and Ho, more preferably Dy and/or Tb.
Wherein, the mass ratio of RH to R′ is preferably less than 0.253, more preferably 0-0.08, for example 1/30.5, 1/32, 1.5/31.85, 2.3/31.9, 1/31, 1.2/30.2, 1.4/30.4, 1.7/30.7, 1.9/31.9, 2.1/31.8, 2.3/31.5, 1/30.5, 1.7/31.7, 1.2/31.2, 1.4/31.4, 1.7/31.7, 0.5/31.5, 0.5/31.3, 1/30.5 or 2.7/32.7.
Wherein, the content of RH is preferably 0.5-2.7%, for example 0.5%, 1%, 1.2%, 1.4%, 1.5%, 1.7%, 1.9%, 2.1%, 2.3% or 2.7%, more preferably 1-2.5%, the percentage is the mass percentage relative to the total mass of the raw material composition of neodymium-iron-boron magnet material.
When RH comprises Tb, the content of Tb is preferably 0.5-2 wt. %, for example 0.5%, 0.7%, 0.8%, 0.9%, 1%, 1.2%, 1.5%, 1.6%, 1.8% or 2%, the percentage is the mass percentage relative to the total mass of the raw material composition of neodymium-iron-boron magnet material.
When RH comprises Dy, the content of Dy is preferably 0.5 wt. % or less, for example 0.1%, 0.2%, 0.3% or 0.5%, the percentage is the mass percentage relative to the total mass of the raw material composition of neodymium-iron-boron magnet material.
When RH comprises Ho, the content of Ho can be the conventional addition amount in the field, usually 0.8-2.0%, for example 1%.
In the present disclosure, the content of Al is preferably 0.5-3 wt. %, for example 0.5%, 0.6%, 0.8%, 0.9%, 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2.0%, 2.1%, 2.2%, 2.3%, 2.5%, 2.7%, 2.8%, 2.9% or 3%, the percentage refers to the mass percentage relative to the total mass of the raw material composition of neodymium-iron-boron magnet material.
In the present disclosure, the content of B is preferably 0.95-1.2%, for example 0.95%, 0.96%, 0.98%, 0.985%, 0.99%, 1%, 1.1% or 1.2%, the percentage refers to the mass percentage relative to the total mass of the raw material composition of neodymium-iron-boron magnet material.
In the present disclosure, the content of Fe is preferably 60-67.515%, for example 60.03%, 62.76%, 62.96%, 63.145%, 63.735%, 63.885%, 63.935%, 64.04%, 64.265%, 64.315%, 64.57%, 64.735%, 64.815%, 64.865%, 64.97%, 64.985%, 65.015%, 65.065%, 65.115%, 65.135%, 65.265%, 65.315%, 65.385%, 65.515%, 65.56%, 65.665%, 65.715%, 65.765%, 65.815%, 65.85%, 65.985%, 65.915%, 65.9655%, 65.995%, 66.065%, 66.115%, 66.165%, 66.215%, 66.315%, 66.465%, 66.515%, 66.665%, 66.715%, 66.75%, 66.815%, 66.915%, 67.115%, 67.215%, 67.315%, 67.4%, 67.415%, 67.515% or 67.615%, the percentage refers to the mass percentage relative to the total mass of the raw material composition of neodymium-iron-boron magnet material.
In the present disclosure, preferably, the raw material composition of neodymium-iron-boron magnet material further comprises Cu.
In the present disclosure, the content of Cu is preferably 0.1-1.2%, for example 0.1%, 0.35%, 0.4%, 0.45%, 0.48%, 0.5%, 0.55%, 0.6%, 0.65%, 0.7%, 0.75%, 0.8%, 0.85%, 0.9%, 1% or 1.1%, the percentage refers to the mass percentage relative to the total mass of the raw material composition of neodymium-iron-boron magnet material.
In the present disclosure, preferably, the raw material composition of neodymium-iron-boron magnet material further comprises Ga.
In the present disclosure, the content of Ga is preferably 0.45 wt. % or less, for example 0.05%, 0.1%, 0.2%, 0.25%, 0.3%, 0.35% or 0.42%, the percentage refers to the mass percentage relative to the total mass of the raw material composition of neodymium-iron-boron magnet material.
In the present disclosure, preferably, the raw material composition of neodymium-iron-boron magnet material further comprises N, preferably, the kind of N comprises Zr, Nb, Hf or Ti.
Wherein, the content of Zr is preferably 0.05-0.5%, for example 0.1%, 0.2%, 0.25%, 0.28%, 0.3% or 0.35%, the percentage refers to the mass percentage relative to the total mass of the raw material composition of neodymium-iron-boron magnet material.
In the present disclosure, preferably, the raw material composition of neodymium-iron-boron magnet material further comprises Co.
Wherein, the content of Co is preferably 0.5-3%, for example 1% or 3%, the percentage refers to the mass percentage relative to the total mass of the raw material composition of neodymium-iron-boron magnet material.
In the present disclosure, the raw material composition of neodymium-iron-boron magnet material usually further comprises 0.
Wherein, the content of 0 is preferably 0.13% or less, the percentage refers to the mass percentage relative to the total mass of the raw material composition of neodymium-iron-boron magnet material.
In the present disclosure, preferably, the raw material composition of neodymium-iron-boron magnet material may further comprise other elements common in the art, for example one or more of Zn, Ag, In, Sn, V, Cr, Mo, Ta and W.
Wherein, the content of Zn can be the conventional content in the field, preferably 0.01-0.1%, for example 0.02% or 0.05%, the percentage refers to the mass percentage relative to the total mass of the raw material composition of neodymium-iron-boron magnet material.
Wherein, the content of Mo can be the conventional content in the field, preferably 0.01-0.1%, for example 0.02% or 0.05%, the percentage refers to the mass percentage relative to the total mass of the raw material composition of neodymium-iron-boron magnet material.
In the present disclosure, the raw material composition of neodymium-iron-boron magnet material preferably comprises the following components by mass percentage: 29.5-32.8% of R′, wherein, R′ refers to rare earth elements, R′ comprises Pr and Nd; wherein, Pr≥17.15%; Al≥0.5%; Cu≤1.2%; 0.90-1.2% of B; 60-68% of Fe; more preferably, the content of Pr is 17.15-30%; more preferably, the content of Al is 0.5-3%; more preferably, the content of Cu is 0.35-1.3%; more preferably, R′ further comprises RH, RH refers to heavy rare earth elements, and the content of RH is preferably 1-2.5%; the percentage is the mass percentage relative to the total mass of the raw material composition of neodymium-iron-boron magnet material.
In the present disclosure, the raw material composition of neodymium-iron-boron magnet material preferably comprises the following components by mass percentage: 29.5-32.8% of R′, wherein, R′ refers to rare earth elements, R′ comprises Pr and Nd; wherein, Pr≥17.15%; Al≥0.5%; 0.25-0.3% of Zr; 0.90-1.2% of B; 60-68% of Fe; more preferably, the content of Pr is 17.15-30%; more preferably, the content of Al is 0.5-3%; more preferably, R′ further comprises RH, RH refers to heavy rare earth elements, and the content of RH is preferably 1-2.5%, the percentage is the mass percentage relative to the total mass of the raw material composition of neodymium-iron-boron magnet material.
In the present disclosure, the raw material composition of neodymium-iron-boron magnet material preferably comprises the following components by mass percentage: 29.5-32.8% of R′, wherein, R′ refers to rare earth elements, R′ comprises Pr and Nd; wherein, Pr≥17.15%; Al≥0.5%; Cu≤1.2%; 0.25-0.3% of Zr; 0.90-1.2% of B; 60-68% of Fe; more preferably, the content of Pr is 17.15-30%; more preferably, the content of Al is 0.5-3%; more preferably, the content of Cu is 0.35-1.3%; more preferably, R′ further comprises RH, RH refers to heavy rare earth elements, and the content of RH is preferably 1-2.5%, the percentage is the mass percentage relative to the total mass of the raw material composition of neodymium-iron-boron magnet material.
In the present disclosure, the raw material composition of neodymium-iron-boron magnet material preferably comprises the following components by mass percentage: 29.5-32.8% of R′, wherein, R′ refers to rare earth elements, R′ comprises Pr and Nd; wherein, Pr≥17.15%; Al≥0.5%; Ga≤0.42%; 0.90-1.2% of B; 60-68% of Fe; more preferably, the content of Pr is 17.15-30%; more preferably, the content of Al is 0.5-3%; more preferably, R′ further comprises RH, RH refers to heavy rare earth elements, and the content of RH is preferably 1-2.5%, the percentage is the mass percentage relative to the total mass of the raw material composition of neodymium-iron-boron magnet material.
In the present disclosure, the raw material composition of neodymium-iron-boron magnet material preferably comprises the following components by mass percentage: 29.5-32.8% of R′, wherein, R′ refers to rare earth elements, R′ comprises Pr and Nd; wherein, Pr≥17.15%; Al≥0.5%; Ga≤0.42%; Cu≤1.2%; 0.90-1.2% of B; 60-68% of Fe; more preferably, the content of Pr is 17.15-30%; more preferably, the content of Al is 0.5-3%; more preferably, the content of Cu is 0.35-1.3%; more preferably, R′ further comprises RH, RH refers to heavy rare earth elements, and the content of RH is preferably 1-2.5%, the percentage is the mass percentage relative to the total mass of the raw material composition of neodymium-iron-boron magnet material.
In the present disclosure, the raw material composition of neodymium-iron-boron magnet material preferably comprises the following components by mass percentage: 29.5-32.8% of R′, wherein, R′ refers to rare earth elements, R′ comprises Pr and Nd; wherein, Pr≥17.15%; Al≥0.5%; Ga≤0.42%; 0.25-0.3% of Zr; 0.90-1.2% of B; 60-68% of Fe; more preferably, the content of Pr is 17.15-30%; more preferably, the content of Al is 0.5-3%; more preferably, R′ further comprises RH, RH refers to heavy rare earth elements, and the content of RH is preferably 1-2.5%, the percentage is the mass percentage relative to the total mass of the raw material composition of neodymium-iron-boron magnet material.
In the present disclosure, the raw material composition of neodymium-iron-boron magnet material preferably comprises the following components by mass percentage: 29.5-32.8% of R′, wherein, R′ refers to rare earth elements, R′ comprises Pr and Nd; wherein, Pr≥17.15%; Al≥0.5%; Ga≤0.42%; Cu≤1.2%; 0.25-0.3% of Zr; 0.90-1.2% of B; 60-68% of Fe; more preferably, the content of Pr is 17.15-30%; more preferably, the content of Al is 0.5-3%; more preferably, the content of Cu is 0.35-1.3%; more preferably, R′ further comprises RH, RH refers to heavy rare earth elements, and the content of RH is preferably 1-2.5%, the kind of RH is preferably Dy and/or Tb, wherein the content of Tb is preferably 0.5-2%; the percentage is the mass percentage relative to the total mass of the raw material composition of neodymium-iron-boron magnet material.
The present disclosure further provides a preparation method for neodymium-iron-boron magnet material, which employs the raw material composition of neodymium-iron-boron magnet material comprising Pr and Al mentioned above to prepare.
In the present disclosure, preferably, the preparation method comprises the following steps: subjecting the molten liquid of the raw material composition of neodymium-iron-boron magnet material mentioned above to melting and casting, hydrogen decrepitation, forming, sintering and aging treatment.
In the present disclosure, the molten liquid of the raw material composition of neodymium-iron-boron magnet material can be prepared by the conventional method in the field, for example: melting in a high frequency vacuum induction melting furnace. The vacuum degree of the melting furnace can be 5×10−2 Pa. The temperature of the melting can be 1500° C. or less.
In the present disclosure, the operations and conditions of casting can be conventional in the field, for example, in Ar atmosphere (for example in Ar atmosphere of 5.5×104 Pa), cooling at 102° C./sec-104° C./sec.
In the present disclosure, the operations and conditions of hydrogen decrepitation can be conventional in the field. For example, being subject to hydrogen absorption, dehydrogenation and cooling treatment.
Wherein, the hydrogen absorption can be carried out at the hydrogen pressure of 0.15 MPa.
Wherein, the dehydrogenation can be carried out under the condition of heating while evacuating.
In the present disclosure, the conventional pulverization in the field can be carried out after hydrogen decrepitation. The pulverization process can be conventional in the field, for example jet mill pulverization. The jet mill pulverization is preferably carried out in nitrogen atmosphere with an oxidizing gas content of 150 ppm or less. The oxidizing gas refers to the content of oxygen or moisture. The pressure in the pulverization chamber of jet mill pulverization is preferably 0.38 MPa; the time of the jet mill pulverization is preferably 3 h.
Wherein, after the pulverization, lubricants can be added to the powder by the conventional method in the field, for example zinc stearate. The amount of lubricant added can be 0.10-0.15%, for example 0.12%, by weight of the mixed powder.
In the present disclosure, the operations and conditions of the forming can be conventional in the field, for example magnetic field forming method or hot press and hot deformation method.
In the present disclosure, the operations and conditions of the sintering can be conventional in the field. For example, preheating, sintering and cooling in vacuum (for example in vacuum of 5×10−3 Pa).
Wherein, the temperature of the preheating is usually 300-600° C. The time of the preheating is usually 1-2 h. The preheating is preferably carried out at 300° C. and 600° C. for 1 h respectively.
Wherein, the temperature of the sintering is preferably 1030-1080° C., for example 1040° C.
Wherein, the time of the sintering is conventional in the field, for example 2h.
Wherein, before the cooling, Ar gas can be introduced to make the pressure reach 0.1 MPa.
In the present disclosure, after the sintering and before the aging treatment, a grain boundary diffusion treatment is further carried out preferably.
Wherein, the operations and conditions of the grain boundary diffusion can be conventional in the field. For example, the surface of the neodymium-iron-boron magnet material is attached with Tb-containing substance and/or Dy-containing substance by evaporating, coating or sputtering, and subjected to diffusion heat treatment.
The Tb-containing substance can be a Tb metal, a Tb-containing compound, for example a Tb-containing fluoride or alloy.
The Dy-containing substance can be a Dy metal, a Dy-containing compound, for example a Dy-containing fluoride or alloy.
The temperature of the diffusion heat treatment may be 800-900° C., for example 850° C.
The time of the diffusion heat treatment can be 12-48 h, for example 24h.
In the present disclosure, in the aging treatment, the temperature of secondary aging treatment is preferably 550-650° C., for example 550° C.
In the present disclosure, in the secondary aging treatment, the temperature is heated to 550-650° C. preferably at a heating rate of 3-5° C./min. The starting point of heating can be room temperature.
In the present disclosure, the room temperature is 25° C.±5° C.
The present disclosure further provides a neodymium-iron-boron magnet material, which is prepared by the preparation method mentioned above.
The present disclosure further provides a neodymium-iron-boron magnet material, which comprises the following components by mass percentage: 29.4-32.8% of R′, R′ comprises Pr and Nd; wherein, Pr≥17.12%;
60-68% of Fe; the percentage is the mass percentage relative to the total mass of the neodymium-iron-boron magnet material.
In the present disclosure, the content of Pr is preferably 17.12-30%, for example 17.12%, 17.13%, 17.14%, 17.15%, 18.13%, 18.14%, 18.15%, 18.16%, 19.12%, 19.14%, 20.05%, 20.13%, 20.14%, 21.12%, 21.13%, 21.14%, 21.15%, 21.16%, 23.11%, 23.12%, 23.13%, 13.15%, 24.16%, 25.12%, 25.13%, 25.14%, 25.16%, 25.17%, 26.52%, 27.15% or 30%, the percentage is the mass percentage relative to the total mass of the neodymium-iron-boron magnet material.
In the present disclosure, the content of Nd is preferably 15% or less, more preferably 1.5-14%, for example 1.5%, 2.45%, 3.83%, 3.84%, 3.86%, 3.89%, 4.03%, 4.52%, 4.82%, 4.83%, 4.84%, 4.86%, 4.87%, 5.84%, 6.82%, 6.83%, 6.84%, 6.86%, 8.33%, 8.34%, 8.35%, 8.36%, 11.55%, 11.63%, 11.64%, 11.66%, 11.85%, 12.82%, 12.83%, 12.84%, 12.85%, 12.89%, 13.81%, 13.82%, 13.84% or 13.85%, the percentage is the mass percentage relative to the total mass of the neodymium-iron-boron magnet material.
In the present disclosure, preferably, the R′ further comprises RH, RH refers to heavy rare earth elements; the kind of RH preferably comprises one or more of Dy, Tb and Ho, more preferably Dy and/or Tb.
Wherein, the mass ratio of RH to R′ is preferably less than 0.253, more preferably 0-0.08.
Wherein, the content of RH is preferably 3% or less, more preferably 0.4-3%, for example 0.48%, 0.51%, 0.56%, 1%, 1.02%, 1.03%, 1.04%, 1.19%, 1.21%, 1.25%, 1.42%, 1.43%, 1.52%, 1.7%, 1.71%, 1.72%, 1.91%, 2.13%, 2.33%, 2.69% or 2.71%, the percentage is the mass percentage relative to the total mass of the neodymium-iron-boron magnet material.
When RH comprises Tb, the content of Tb is preferably 0.5-2.1%, for example 0.51%, 0.56%, 0.69%, 0.71%, 0.81%, 0.83%, 0.88%, 0.9%, 1%, 1.01%, 1.02%, 1.03%, 1.04%, 1.2%, 1.21%, 1.5%, 1.58%, 1.59%, 1.6%, 1.8%, 2.01% or 1.02%, the percentage is the mass percentage relative to the total mass of the neodymium-iron-boron magnet material.
When RH comprises Dy, the content of Dy is preferably 0.51% or less, preferably 0.1-0.51%, for example 0.11%, 0.12%, 0.13%, 0.19%, 0.21%, 0.22%, 0.23%, 0.29%, 0.31%, 0.32%, 0.48%, 0.49% or 0.51%, the percentage is the mass percentage relative to the total mass of the neodymium-iron-boron magnet material.
When RH comprises Ho, the content of Ho can be the conventional addition amount in the field, usually 0.8-2%, for example 1%, the percentage is the mass percentage relative to the total mass of the neodymium-iron-boron magnet material.
In the present disclosure, the content of Al is preferably 0.48-3%, for example 0.48%, 0.49%, 0.58%, 0.6%, 0.61%, 0.8%, 0.82%, 0.83%, 0.89%, 0.9%, 0.91%, 0.92%, 1.01%, 1.02%, 1.03%, 1.04%, 1.09%, 1.21%, 1.22%, 1.23%, 1.31%, 1.42%, 1.49%, 1.51%, 1.52%, 1.53%, 1.62%, 1.63%, 1.7%, 1.79%, 1.81%, 1.82%, 1.9%, 1.91%, 1.92%, 2.01%, 2.02%, 2.03%, 1.12%, 2.21%, 2.3%, 2.31%, 2.52%, 2.71%, 2.91% or 2.98%, the percentage is the mass percentage relative to the total mass of the neodymium-iron-boron magnet material.
In the present disclosure, the content of B is preferably 0.95-1.2%, for example 0.951%, 0.962%, 0.981%, 0.982%, 0.983%, 0.984%, 0.985%, 0.986%, 0.99%, 0.998%, 1.03% or 1.11%, the percentage is the mass percentage relative to the total mass of the neodymium-iron-boron magnet material.
In the present disclosure, the content of Fe is preferably 59.9-67.7%, for example 59.932%, 62.8%, 62.88%, 63.136%, 63.896%, 64.029%, 64.234%, 64.266%, 64.566%, 64.799%, 64.897%, 64.915%, 64.985%, 64.987%, 65.084%, 65.096%, 65.146%, 65.264%, 65.299%, 65.309%, 65.327%, 65.347%, 65.385%, 65.514%, 65.524%, 65.548%, 65.664% 65.665%, 65.689%, 65.779%, 65.829%, 65.867%, 65.877%, 65.896%, 65.944%, 66.019%, 66.047%, 66.174%, 66.236%, 66.249%, 66.327%, 66.386%, 66.496%, 66.534%, 66.964%, 66.699%, 66.73%, 66.847%, 66.917%, 67.029%, 67.088%, 67.115%, 67.216%, 67.224%, 67.315%, 67.426%, 67.45%, 67.526%, 67.587% or 67.607%, the percentage is the mass percentage relative to the total mass of the neodymium-iron-boron magnet material.
In the present disclosure, the neodymium-iron-boron magnet material preferably further comprises Cu.
In the present disclosure, the content of Cu is preferably 1.2% or less, for example 0.11%, 0.34%, 0.35%, 0.4%, 0.41%, 0.45%, 0.5%, 0.51%, 0.55%, 0.6%, 0.63%, 0.65%, 0.72%, 0.75%, 0.81%, 0.85%, 0.91%, 1.02%, 1.03%, 1.04% or 1.11%, more preferably 0.34-1.3%, the percentage is the mass percentage relative to the total mass of the neodymium-iron-boron magnet material.
In the present disclosure, the neodymium-iron-boron magnet material preferably further comprises Ga.
In the present disclosure, the content of Ga is preferably 0.42% or less, for example 0.05%, 0.1%, 0.2%, 0.23%, 0.25%, 0.251%, 0.31%, 0.34%, 0.36%, 0.41%, 0.42%, 0.43% or 0.44%, more preferably 0.25-0.42%, the percentage is the mass percentage relative to the total mass of the neodymium-iron-boron magnet material.
In the present disclosure, the neodymium-iron-boron magnet material preferably further comprises N, and the kind of N preferably comprises Zr, Nb, Hf or Ti.
Wherein, the content of the Zr is preferably 0.05-0.5%, for example 0.1%, 0.11%, 0.2%, 0.22%, 0.24%, 0.25%, 0.27%, 0.28%, 0.3%, 0.31%, 0.32%, 0.34%, 0.35%, 0.36%, 0.37% or 0.38%, the percentage is the mass percentage relative to the total mass of the neodymium-iron-boron magnet material.
In the present disclosure, the neodymium-iron-boron magnet material preferably further comprises Co.
In the present disclosure, the content of Co is preferably 0.5-3.5%, for example 1% or 3.03%, the percentage refers to the mass percentage relative to the total mass of the raw material composition of neodymium-iron-boron magnet material.
In the present disclosure, the neodymium-iron-boron magnet material usually further comprises O.
Wherein, the content of O is preferably 0.13% or less, the percentage refers to the mass percentage relative to the total mass of the raw material composition of neodymium-iron-boron magnet material.
In the present disclosure, the neodymium-iron-boron magnet material can further comprise other conventional elements in the field, for example one or more of Zn, Ag, In, Sn, V, Cr, Nb, Mo, Ta and W.
Wherein, the content of Zn can be the conventional content in the field, preferably 0.01-0.1%, for example 0.03% or 0.04%, the percentage refers to the mass percentage of each component relative to the total mass of the neodymium-iron-boron magnet material.
Wherein, the content of Mo can be the conventional content in the field, preferably 0.01-0.1%, for example 0.02% or 0.06%, the percentage refers to the mass percentage of each component relative to the total mass of the neodymium-iron-boron magnet material.
In the present disclosure, the neodymium-iron-boron magnet material preferably comprises the following components by mass percentage: 29.4-32.8% of R′, wherein, R′ refers to rare earth elements, R′ comprises Pr and Nd; wherein, Pr≥17.12%; Al≥0.48%; Cu≤1.2%; 0.90-1.2% of B; 60-68% of Fe; more preferably, the content of Pr is 17.12-30%; more preferably, the content of Al is 0.48-3%; more preferably, the content of Cu is 0.34-1.3%; more preferably, R′ further comprises RH, RH refers to heavy rare earth elements, and the content of RH is preferably 1-2.5%; the percentage is the mass percentage of each component relative to the total mass of the neodymium-iron-boron magnet material.
In the present disclosure, the neodymium-iron-boron magnet material preferably comprises the following components by mass percentage: 29.4-32.8% of R′, wherein, R′ refers to rare earth elements, R′ comprises Pr and Nd; wherein, Pr≥17.12%; Al≥0.48%; 0.25-0.3% of Zr; 0.90-1.2% of B; 60-68% of Fe; more preferably, the content of Pr is 17.12-30%; more preferably, the content of Al is 0.48-3%; more preferably, R′ further comprises RH, RH refers to heavy rare earth elements, and the content of RH is preferably 1-2.5%; the percentage is the mass percentage of each component relative to the total mass of the neodymium-iron-boron magnet material.
In the present disclosure, the neodymium-iron-boron magnet material preferably comprises the following components by mass percentage: 29.4-32.8% of R′, wherein, R′ refers to rare earth elements, R′ comprises Pr and Nd; wherein, Pr≥17.12%; Al≥0.48%; Cu≤1.2%; 0.25-0.3% of Zr; 0.90-1.2% of B; 60-68% of Fe; more preferably, the content of Pr is 17.12-30%; more preferably, the content of Al is 0.48-3%; more preferably, the content of Cu is 0.34-1.3%; more preferably, R′ further comprises RH, RH refers to heavy rare earth elements, and the content of RH is preferably 1-2.5%; the percentage is the mass percentage of each component relative to the total mass of the neodymium-iron-boron magnet material.
In the present disclosure, the neodymium-iron-boron magnet material preferably comprises the following components by mass percentage: 29.4-32.8% of R′, wherein, R′ refers to rare earth elements, R′ comprises Pr and Nd; wherein, Pr≥17.12%; Al≥0.48%; Ga≤0.44%; 0.90-1.2% of B; 60-68% of Fe; more preferably, the content of Pr is 17.12-30%; more preferably, the content of Al is 0.48-3%; more preferably, R′ further comprises RH, RH refers to heavy rare earth elements, and the content of RH is preferably 1-2.5%; the percentage is the mass percentage of each component relative to the total mass of the neodymium-iron-boron magnet material.
In the present disclosure, the neodymium-iron-boron magnet material preferably comprises the following components by mass percentage: 29.4-32.8% of R′, wherein, R′ refers to rare earth elements, R′ comprises Pr and Nd; wherein, Pr≥17.12%; Al≥0.48%; Ga≤0.44%; Cu≤1.2%; 0.90-1.2% of B; 60-68% of Fe; more preferably, the content of Pr is 17.15-30%; more preferably, the content of Al is 0.48-3%; more preferably, the content of Cu is 0.34-1.3%; more preferably, R′ further comprises RH, RH refers to heavy rare earth elements, and the content of RH is preferably 1-2.5%; the percentage is the mass percentage of each component relative to the total mass of the neodymium-iron-boron magnet material.
In the present disclosure, the neodymium-iron-boron magnet material preferably comprises the following components by mass percentage: 29.4-32.8% of R′, wherein, R′ refers to rare earth elements, R′ comprises Pr and Nd; wherein, Pr≥17.12%; Al≥0.48%; Ga≤0.44%; 0.25-0.3% of Zr; 0.90-1.2% of B; 60-68% of Fe; more preferably, the content of Pr is 17.12-30%; more preferably, the content of Al is 0.48-3%; more preferably, R′ further comprises RH, RH refers to heavy rare earth elements, and the content of RH is preferably 1-2.5%; the percentage is the mass percentage of each component relative to the total mass of the neodymium-iron-boron magnet material.
In the present disclosure, the neodymium-iron-boron magnet material preferably comprises the following components by mass percentage: 29.4-32.8% of R′, wherein, R′ refers to rare earth elements, R′ comprises Pr and Nd; wherein, Pr≥17.12%; Al≥0.48%; Ga≤0.44%; Cu≤1.2%; 0.25-0.3% of Zr; 0.90-1.2% of B; 60-68% of Fe; more preferably, the content of Pr is 17.12-30%; more preferably, the content of Al is 0.5-3%; more preferably, the content of Cu is 0.34-1.3% more preferably, R′ further comprises RH, RH refers to heavy rare earth elements, and the content of RH is preferably 1-2.5%; the percentage is the mass percentage of each component relative to the total mass of the neodymium-iron-boron magnet material.
The present disclosure further provides a neodymium-iron-boron magnet material, in the intergranular triangle region of the neodymium-iron-boron magnet material, the ratio of the total mass of Pr and Al to the total mass of Nd and Al is ≤1.0;
at the grain boundary of the neodymium-iron-boron magnet material, the ratio of the total mass of Pr and Al to the total mass of Nd and Al is ≥0.1;
Preferably, the components of the neodymium-iron-boron magnet material refer to those of the neodymium-iron-boron magnet material mentioned above.
In the present disclosure, the grain boundary refers to the boundary between two grains, and the intergranular triangle region is the gap formed by three and more grains.
The present disclosure further provides a use of the neodymium-iron-boron magnet material as an electronic component in a motor.
Based on the common sense in the field, the preferred conditions of the preparation methods can be combined arbitrarily to obtain preferred examples of the present disclosure.
The reagents and raw materials used in the invention are commercially available.
The positive progress of the present invention is that: in the prior art, adding Pr and Al to the neodymium-iron-boron magnet material can increase the coercive force, but reduce the remanence at the same time. Through a large number of experiments, the inventor found that the compatibility of a specific content of Pr and Al can produce a synergistic effect, that is, adding a specific content of Pr and Al at the same time can make the coercivity of the neodymium-iron-boron magnet more significantly improved, while the remanence is only slightly reduced. And the magnet material in the present disclosure still has high coercivity and remanence without adding heavy rare earth elements.
The following examples further illustrate the present disclosure, but the present disclosure is not limited thereto. Experiment methods in which specific conditions are not indicated in the following embodiments are selected according to conventional methods and conditions, or according to the product specification. In the table below, wt. % refers to the mass percentage of the component in the raw material composition of the R-T-B permanent magnet material, and “/” indicates that the element has not been added. “Br” is the residual magnetic flux density and “Hcj” is the intrinsic coercivity.
The formulations for the raw material compositions of the neodymium-iron-boron magnet materials in each Examples 1-45 and Comparative Examples 46-49 are shown in Table 1 below.
The neodymium-iron-boron magnet material comprising Pr and Al was prepared as follows:
(1) Melting and casting: according to the formulation for the raw material compositions in each Example and Comparative Example shown in Table 1, the prepared raw material was put into a crucible made of alumina and vacuum melted in a high frequency vacuum induction melting furnace and in a vacuum of 5×10−2 Pa at a temperature of 1500° C. or less. After the vacuum melting, Ar gas was introduced into the melting furnace to make the pressure reach 55,000 Pa, then casting was carried out, and the quenched alloy was obtained at a cooling rate of 102° C./sec to 104° C./sec.
(2) Hydrogen decrepitation: the melting furnace in which the quench alloy was placed was evacuated at room temperature, and then hydrogen of 99.9% purity was introduced into the furnace for hydrogen decrepitation to maintain the hydrogen pressure at 0.15 MPa; after full hydrogen absorption, vacuuming was conducted while heating up to fully dehydrogenate; then cooling was carried out and the powder after hydrogen decrepitation was taken out.
(3) Micro pulverization process: the powder after hydrogen decrepitation was pulverized by jet mill for 3 hours under a nitrogen atmosphere with an oxidizing gas content of 150 ppm or less and under a pressure of 0.38 MPa in the pulverization chamber to obtain a fine powder. The oxidizing gas referred to oxygen or moisture.
(4) Zinc stearate was added to the powder from jet mill pulverization, and the addition amount of zinc stearate was 0.12% by weight of the mixed powder, and then mixed thoroughly with a V-mixer.
(5) Magnetic field forming process: the above-mentioned zinc stearate added powder was formed into a cube with a side length of 25 mm through primary forming by using a rectangular oriented magnetic field forming machine at an oriented magnetic field of 1.6 T and a forming pressure of 0.35 ton/cm2; and it was demagnetized in a magnetic field of 0.2 T after the primary forming. In order to prevent the formed body obtained after the primary forming from being exposed to air, it was sealed, and then a secondary forming machine (isostatic forming machine) was used to perform secondary forming at a pressure of 1.3 ton/cm2.
(6) Sintering process: each formed body was moved to the sintering furnace for sintering, which was held in vacuum of 5×10−3 Pa at 300° C. and 600° C. for 1 hour respectively; then, sintered at 1040° C. for 2 hours; then cooled to room temperature after the pressure reached 0.1 MPa by introducing Ar gas, to obtain sintered body.
(7) Aging treatment process: the sintered body was heat treated in high purity Ar gas at 600° C. for 3 hours and then heated to 550° C. at a heating rate of 3° C./min, it was cooled to room temperature before being taken out.
The parameters in the preparation processes of Examples 1-45 and Comparative Examples 46-49 were the same as Example 1 except that the formulations of the raw material compositions are different selected in the preparation processes.
The neodymium-iron-boron magnet material of Example 50 was obtained by employing the Dy grain boundary diffusion method based on the raw material composition of Example 1, and the preparation process was as follows:
The No. 1 in Table 1 was first prepared according to the preparation of the sintered body of Example 1 to obtain a sintered body, followed by grain boundary diffusion, and then the aging treatment was carried out. Wherein, the process of aging treatment was the same as in Example 1, and the process of grain boundary diffusion was as follows:
The sintered body was processed into a magnet with a diameter of 20 mm and a sheet thickness of less than 3 mm in the direction of the magnetic field orientation, and after surface cleaning, the magnet was coated with a full spray using a raw material prepared with Dy fluoride, and the coated magnet was dried and the metal attached with Tb element was sputtered on the magnet surface in a high purity Ar atmosphere, diffusion heat treatment was carried out at the temperature of 850° C. for 24 hours. Cooled to room temperature.
The neodymium-iron-boron magnet material of Example 51 was obtained by employing the Dy grain boundary diffusion method based on the raw material composition of Example 1, and the preparation process was as follows:
The No. 1 in Table 1 was first prepared according to the preparation of the sintered body of Example 1 to obtain a sintered body, followed by grain boundary diffusion, and then the aging treatment was carried out. Wherein, the process of aging treatment was the same as in Example 1, and the process of grain boundary diffusion was as follows:
The sintered body was processed into a magnet with a diameter of 20 mm and a sheet thickness of less than 7 mm in the direction of the magnetic field orientation, and after surface cleaning, the magnet was coated with a full spray using a raw material prepared with Tb fluoride, respectively, and the coated magnet was dried and the metal with attached Tb element was sputtered on the magnet surface in a high purity Ar atmosphere, diffusion heat treatment was carried out at the temperature of 850° C. for 24 hours. Cooled to room temperature.
The magnetic properties and compositions of the neodymium-iron-boron magnet materials produced in each Example and Comparative Example were measured and the crystalline phase structure of the magnets was observed by FE-EPMA.
(1) Magnetic properties evaluation: The magnet materials were tested for magnetic properties by using the NIM-10000H BH bulk rare earth permanent magnet non-destructive measurement system from the National Institute of Metrology, China. The results of the magnetic properties testing were shown in Table 2 below.
(2) Component determination: each component was determined by using a high frequency inductively coupled plasma emission spectrometer (ICP-OES). The component determination results of the neodymium-iron-boron magnet materials in each Example and Comparative Example were shown in Table 3 below.
(3) FE-EPMA inspection: The neodymium-iron-boron magnet material of Example 11 was tested by the Field Emission Electron Probe Micro-Analyzer (FE-EPMA) (Japan Electronics Company (JEOL), 8530F). The elements of Pr, Nd, Al, Zr and O in the magnet material were determined, and the elements at the grain boundary and the intergranular triangular region were quantitatively analyzed. Wherein: the grain boundary refer to the boundary between two grains, and the intergranular triangle region refer to the gap formed by three and more grains.
It can be seen from
From the above data, it can be seen that Pr and Nd were present at the grain boundary in the form of rare earth rich phases and oxides, which were respectively a-Pr and a-Nd, Pr2O3, Nd2O3 and NdO, and Al occupied a certain content of about 0.2 wt. % at the grain boundary in addition to the main phase, for example 0.19 wt. % in this example. Zr as a high melting point element was diffusely distributed throughout the region.
As shown in
It can be seen from Table 5 that Pr and Nd elements were distributed in the intergranular triangular region. In the formulation of this example, it is clearly found that the content of Pr is obviously lower than that of Nd in the intergranular triangular region, although rare earths are partially enriched here, the enrichment degree of Pr is less than that of Nd, which is one of the reasons why high Pr and Al work together to improve the coercivity. At the same time, there is a partial distribution of O and Zr therein.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201911150984.0 | Nov 2019 | CN | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2020/100588 | 7/7/2020 | WO |
