Low-cost high-temperature-resistant permanent magnet material, preparation method thereof, magnet and device

Abstract

The invention relates to the field of permanent magnet materials, and particularly provides a low-cost high-temperature-resistant permanent magnet material and a preparation method thereof, a magnet and a device, and the structural general formula of the permanent magnet material is (NdxPr1-x) aCebLacCodZreNbfFegBh, wherein 0 < = x < = 1, 11.4 < = a + b + c < = 13.5, 0 < b + c, 0 < = b < = 10.0, 0 < = c < = 5.0, 0 < = d < = 10.0, 0 < = e < = 9.0, 0 < = f < = 5.0, 4.8 < = h < = 7.2, and a + b + c + d + e + f + g + h = 100. By directly replacing Nd or PrNd with La or Ce or LaCe and adding trace elements Co, Zr and Nb for systematic research, the permanent magnet material has relatively high coercive force at room temperature and high temperature, and a magnet prepared from the permanent magnet material has relatively low demagnetization rate at high temperature and has the characteristics of low cost and high temperature resistance.

Description

Technical Field

[0001] The invention relates to the field of permanent magnetic materials, and in particular to a low-cost and high-temperature-resistant permanent magnetic material and a preparation method thereof, a magnet and a device. Background Art

[0002] At present, the rare earth elements used in commercially available NdFeB permanent magnet materials are mainly Pr and Nd. With the rapid development of automation technology, energy conservation and emission reduction, and new energy technology, the demand for NdFeB permanent magnet materials continues to increase, and the demand for Pr and Nd has also increased significantly. However, due to the high market prices of Pr (praseodymium) and Nd (neodymium), the overall cost of NdFeB permanent magnet materials has increased.

[0003] In order to reduce the cost of magnets, NdFeB magnetic powder doped with lanthanum (La) and cerium (Ce) has been launched on the market in recent years. For example, in January 2025, the price of metal lanthanum was 21,000-22,000 yuan / ton, the price of metal cerium was 24,500-25,500 yuan / ton, and the price of metal neodymium was 504,000-508,000 yuan / ton. Studies have shown that replacing part of the neodymium (Nd) or praseodymium-neodymium (PrNd) elements with La or Ce, or a mixture of La and Ce, will lead to a decrease in the high temperature resistance of permanent magnet materials. The room temperature coercivity (Hcj) of these materials is mostly less than 10kOe. Although there are permanent magnet materials containing Ce or La, or LaCe with Hcj ≥ 10kOe at room temperature, their high temperature performance is still poor. Once the temperature exceeds 200°C, its Hcj will drop sharply, dropping to only 0-2kOe at 250°C. For example, the permanent magnetic material containing LaCe, Co, Zr and Nb proposed in US Pat. No. 6,979,409 has an Hcj of approximately 6.0-9.9 kOe, and the Hcj of the magnet prepared from the material drops sharply at a temperature above 200° C., so the magnet cannot withstand a high temperature environment. Summary of the invention

[0004] The purpose of the present invention is to provide a low-cost high-temperature-resistant permanent magnetic material and its preparation method, magnet and device in view of the problem that the low-cost NdFeB magnetic material doped with lanthanum (La) and cerium (Ce) in the prior art exhibits low coercivity at room temperature and high temperature, the prepared magnet has a low high-temperature demagnetization rate, and poor high-temperature resistance. The present invention conducts a systematic study on directly replacing Nd or PrNd with La or Ce or LaCe, and adding trace elements Co, Zr and Nb. The permanent magnetic material has a high coercivity at room temperature or high temperature, and the magnet prepared by the permanent magnetic material has a low demagnetization rate at high temperature, showing the characteristics of low cost and high temperature resistance.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A low-cost, high-temperature-resistant permanent magnetic material, comprising a composition shown in formula (I),

[0007] (Nd x Pr 1-x ) a Ce b La c Co d Zr e Nb f Fe g B h (I);

[0008] Among them, 0≤x≤1, 11.4≤a+b+c≤13.5, 0<b+c, 0≤b≤10.0, 0≤c≤5.0, 0≤d≤10.0, 0≤e≤9.0, 0≤f≤5.0, 4.8≤h≤7.2, a+b+c+d+e+f+g+h equals 100.

[0009] The present invention provides a low-cost high-temperature resistant permanent magnetic material, the general structural formula of which is (Nd x Pr 1-x ) a Ce b La c Co d Zr e Nb f Fe g B h ; Wherein, 0≤x≤1, 11.4≤a+b+c≤13.5, 0<b+c, 0≤b≤10.0, 0≤c≤5.0, 0≤d≤10.0, 0≤e≤9.0, 0≤f≤5.0, 4.8≤h≤7.2, a+b+c+d+e+f+g+h equals 100. Through systematic research on direct substitution of La or Ce or LaCe for Nd or PrNd, and addition of trace elements Co, Zr and Nb, the permanent magnetic material has a high coercive force at room temperature or high temperature, and the magnet prepared by the permanent magnetic material has a low demagnetization rate at high temperature, showing the characteristics of low cost and high temperature resistance. Specifically, the Hcj value of the permanent magnet material at 20°C can reach above 9.5kOe. At the same time, the Hcj value at 250°C can still reach above 3.0kOe. The high-temperature demagnetization rate of the bonded NdFeB magnet with a size of Φ10×10mm made of permanent magnet material can be lower than 20%, achieving unexpected technical effects.

[0010] Furthermore, when b>0, d>0. Studies have found that when Ce is added to the permanent magnetic material, Co needs to be added to reduce the high-temperature demagnetization rate of the prepared magnet, thereby ensuring that the magnetic material exhibits high temperature resistance.

[0011] Preferably, 11.8≤a+b+c≤13.5, 0≤b≤5.6, 0≤c≤2.9, b≤d. When the amount of Co is greater than the amount of Ce added and the conditions of a, b, and c are met, the magnetic material can exhibit better high temperature resistance.

[0012] Furthermore,

[0013] When e>0, f=0, e satisfies formula (II):

[0014] (m-((a+b+c)×(0.5×a+0.09×b+0.05×c)-(9.3×a+1.68×b+0.93×c)+(50×a+13×b+10.7×c) / (a+b+c)))×0.9≤e≤9.0(II),

[0015] When f>0, e=0, f satisfies formula (III):

[0016] (m-((a+b+c)×(0.5×a+0.09×b+0.05×c)-(9.3×a+1.68×b+0.93×c)+(50×a+13×b+10.7×c) / (a+b+c)))

[0017] ×0.7≤f≤5.0(III);

[0018] Among them, m is 9.9 to 15.5.

[0019] The inventors systematically studied the conditions for e to be satisfied when e>0, f=0, and the conditions for f to be satisfied when f>0, e=0. When these conditions are met, the prepared magnetic material has Hcj≥m kOe at 20℃ and Hcj>3kOe at high temperature (250℃). The high-temperature demagnetization rate of the bonded NdFeB magnet with a size of Φ10×10mm is ≤20% (the high-temperature demagnetization test conditions are: 250℃×2h, open circuit test).

[0020] Preferably, when e>0, f>0, e is converted to f or f is converted to e according to e:f=1:0.78, and the converted e satisfies formula (II) or f satisfies formula (III).

[0021] Another object of the present invention is to provide a method for preparing the above-mentioned low-cost and high-temperature-resistant permanent magnetic material.

[0022] A method for preparing the above-mentioned low-cost and high-temperature-resistant permanent magnetic material comprises the following steps:

[0023] Step 1, weighing various raw materials according to the proportion of formula (I), mixing the weighed raw materials, and smelting them into alloy ingots;

[0024] Step 2, melting the alloy ingot obtained in step 1 and rapidly cooling it into a nano alloy strip;

[0025] Step 3: crushing the alloy strip obtained in step 2 to obtain a low-cost and high-temperature-resistant permanent magnetic material.

[0026] The preparation method is simple to operate and easy to control.

[0027] Another object of the present invention is to provide a magnet made of the above-mentioned low-cost and high-temperature-resistant permanent magnetic material.

[0028] A magnet is made of the above-mentioned low-cost and high-temperature-resistant permanent magnetic material.

[0029] The magnet can show a lower demagnetization rate at high temperature.

[0030] Another object of the present invention is to provide a device comprising the above-mentioned magnet.

[0031] A device is manufactured by processing the above-mentioned magnet.

[0032] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0033] The present invention provides a low-cost high-temperature resistant permanent magnetic material, the general structural formula of which is (Nd x Pr 1-x ) a Ce b La c Co d Zr e Nb f Fe g B h ; Among them, 0≤x≤1, 11.4≤a+b+c≤13.5, 0<b+c, 0≤b≤10.0, 0≤c≤5.0, 0≤d≤10.0, 0≤e≤9.0, 0≤f≤5.0, 4.8≤h≤7.2, a+b+c+d+e+f+g+h equals 100. Through systematic research on direct substitution of La or Ce or LaCe for Nd or PrNd, and addition of trace elements Co, Zr and Nb, the permanent magnetic material has high coercivity at room temperature or high temperature, and the magnet prepared with the permanent magnetic material has low demagnetization rate at high temperature, showing the characteristics of low cost and high temperature resistance. Specifically, the Hcj value of the permanent magnetic material at 20°C can reach more than 9.5kOe, and at the same time, the Hcj value at 250°C can still reach more than 3.0kOe, and the high-temperature demagnetization rate of the bonded NdFeB magnet with a size of Φ10×10mm made of permanent magnetic material can be less than 20%, achieving unexpected technical effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is the demagnetization curve of the permanent magnetic material of Example 12.

[0035] Figure 2 Demagnetization curve of bonded NdFeB made of permanent magnet material in Example 12. DETAILED DESCRIPTION

[0036] The present invention will be described in detail below in conjunction with the accompanying drawings.

[0037] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0038] Example

[0039] At present, the rare earth elements used in commercially available NdFeB permanent magnet materials are mainly Pr and Nd. With the rapid development of automation technology, energy conservation and emission reduction, and new energy technology, the demand for NdFeB permanent magnet materials continues to increase, and the demand for Pr and Nd has also increased significantly. However, due to the high market prices of Pr (praseodymium) and Nd (neodymium), the overall cost of NdFeB permanent magnet materials has increased.

[0040] In order to reduce the cost of magnets, NdFeB magnetic powder doped with lanthanum (La) and cerium (Ce) has been launched on the market in recent years. However, studies have shown that replacing part of the neodymium (Nd) or praseodymium neodymium (PrNd) elements with La or Ce, or a mixture of La and Ce, will lead to a decrease in the high temperature resistance of permanent magnet materials. The room temperature coercivity (Hcj) of these materials is mostly less than 10kOe. Although there are permanent magnet materials containing Ce or La, or LaCe with Hcj ≥ 10kOe at room temperature, their high temperature performance is still poor. Once the temperature exceeds 200°C, its Hcj will drop sharply, dropping to only 0-2kOe at 250°C.

[0041] To this end, the present invention provides a low-cost and high-temperature-resistant permanent magnetic material, which is as follows:

[0042] Comprising the composition shown in formula (I),

[0043] (Nd x Pr 1-x ) a Ce b La c Co d Zr e Nb f Fe g B h (I);

[0044] Among them, 0≤x≤1, 11.4≤a+b+c≤13.5, 0<b+c, 0≤b≤10.0, 0≤c≤5.0, 0≤d≤10.0, 0≤e≤9.0, 0≤f≤5.0, 4.8≤h≤7.2, a+b+c+d+e+f+g+h equals 100.

[0045] Through systematic research on direct substitution of La or Ce or LaCe for Nd or PrNd, and addition of trace elements Co, Zr and Nb, the permanent magnetic material has high coercivity at room temperature or high temperature, and the magnet prepared with the permanent magnetic material has low demagnetization rate at high temperature, showing the characteristics of low cost and high temperature resistance. Specifically, the Hcj value of the permanent magnetic material at 20°C can reach more than 9.5kOe, and at the same time, the Hcj value at 250°C can still reach more than 3.0kOe, and the high-temperature demagnetization rate of the bonded NdFeB magnet with a size of Φ10×10mm made of permanent magnetic material can be less than 20%, achieving unexpected technical effects.

[0046] In some embodiments, when b>0, d>0. Studies have found that when Ce is added to the permanent magnetic material, Co needs to be added to reduce the high temperature demagnetization rate of the prepared magnet, thereby ensuring that the magnetic material exhibits high temperature resistance.

[0047] Preferably, 11.8≤a+b+c≤13.5, 0≤b≤5.6, 0≤c≤2.9, b≤d. When the amount of Co is greater than the amount of Ce added and the conditions of a, b, and c are met, the magnetic material can exhibit better high temperature resistance.

[0048] In some embodiments,

[0049] When e>0, f=0, e satisfies:

[0050] (m-((a+b+c)×(0.5×a+0.09×b+0.05×c)-(9.3×a+1.68×b+0.93×c)+(50×a+13×b+10.7×c) / (a+b+c)))×0.9≤e≤9.0,

[0051] When f>0, e=0, f satisfies:

[0052] (m-((a+b+c)×(0.5×a+0.09×b+0.05×c)-(9.3×a+1.68×b+0.93×c)+(50×a+13×b+10.7×c) / (a+b+c)))×0.7≤f≤5.0;

[0053] Among them, m is 9.9 to 15.5.

[0054] The inventors systematically studied the conditions for e to be satisfied when e>0, f=0, and the conditions for f to be satisfied when f>0, e=0. When these conditions are met, the prepared magnetic material has Hcj≥m kOe at 20°C, and the high-temperature demagnetization rate of the bonded NdFeB magnet with a size of Φ10×10mm is ≤20% (high-temperature demagnetization test conditions are: 250°C×2h, open circuit test).

[0055] When e>0, f>0, e is converted to f or f is converted to e according to e:f=1:0.78, and the converted e satisfies formula (II) or f satisfies formula (III).

[0056] In some embodiments,

[0057] When e>0, f=0, e satisfies:

[0058] (9.9-((a+b+c)×(0.5×a+0.09×b+0.05×c)-(9.3×a+1.68×b+0.93×c)+(50×a+13×b+10.7×c) / (a+b

[0059] +c)))×0.9≤e≤9.0,

[0060] When f>0, e=0, f satisfies:

[0061] (9.9-((a+b+c)×(0.5×a+0.09×b+0.05×c)-(9.3×a+1.68×b+0.93×c)+(50×a+13×b+10.7×c) / (a+b+c)))×0.7≤f≤5.0.

[0062] The low-cost, high-temperature-resistant, rapid-quenching permanent magnetic material has an Hcj≥9.9kOe at 20°C, and the high-temperature demagnetization rate of the bonded NdFeB magnet with a size of Φ10×10mm manufactured by it is ≤20% (high-temperature demagnetization test conditions are: 250°C×2h, open circuit test).

[0063] In some embodiments,

[0064] When e>0, f=0, e satisfies:

[0065] (11-((a+b+c)×(0.5×a+0.09×b+0.05×c)-(9.3×a+1.68×b+0.93×c)+(50×a+13×b+10.7×c) / (a+b+

[0066] c)))×0.9≤e≤9.0,

[0067] When f>0, e=0, f satisfies:

[0068] (11-((a+b+c)×(0.5×a+0.09×b+0.05×c)-(9.3×a+1.68×b+0.93×c)+(50×a+13×b+10.7×c) / (a+b+c)))×0.7≤f≤5.0.

[0069] The low-cost, high-temperature-resistant, rapid-quenching permanent magnetic material has an Hcj≥11kOe at 20°C, and the high-temperature demagnetization rate of the bonded NdFeB magnet with a size of Φ10×10mm manufactured by it is ≤15% (high-temperature demagnetization test conditions are: 250°C×2h, open circuit test).

[0070] The present invention discloses some specific embodiments, as follows:

[0071] 1. Low-cost high-temperature resistant permanent magnetic material containing Ce

[0072] The data of comparative examples and embodiments are shown in Table 1.

[0073] Comparative Example 1 is an existing high-Nd content rapid quenching permanent magnet material, whose Hcj at 20°C reaches 15.93kOe, and Hcj at 250°C reaches 3.71kOe. The bonded NdFeB magnet with a size of Φ10×10mm made of this material is subjected to a high-temperature demagnetization test (conditions: 250°C×2h, open circuit test), and its high-temperature demagnetization rate is 13.91%. This material has good temperature resistance, but the cost is very high.

[0074] Comparative Example 2 is an existing Nb-added rapid quenching permanent magnet material, whose Hcj at 20°C reaches 12.27kOe, and Hcj at 250°C reaches 4.23kOe. The bonded NdFeB magnet with a size of Φ10×10mm manufactured using this material was subjected to a high-temperature demagnetization test (conditions: 250°C×2h, open circuit test), and its high-temperature demagnetization rate was 11.73%. This material has good temperature resistance, but the rare earth elements used are all Nd, and its cost is also very high.

[0075] The conventional way to reduce costs is to use cheap Ce to replace Nd or PrNd, but directly using Ce to replace cannot maintain the high temperature resistance of the quick-quenching permanent magnet material. Comparative Example 3 is based on Comparative Example 1, using Ce to replace part of the Nd. After substitution, the quick-quenching permanent magnet material still has 12.33kOe at 20°C Hcj, but only 1.50kOe at 250°C Hcj. The bonded NdFeB magnet with a size of Φ10×10mm made of this material was subjected to a high-temperature demagnetization test (conditions: 250°C×2h, open circuit test), and its high-temperature demagnetization rate was 55.96%. Comparative Example 4 is based on Comparative Example 2, using Ce to replace Nd, and increasing the content of Nb. After substitution, the quick-quenching permanent magnet material still has 11.68kOe at 20°C Hcj, but only 1.57kOe at 250°C Hcj. The bonded NdFeB magnets with a size of Φ10×10mm made of this material were subjected to a high-temperature demagnetization test (conditions: 250℃×2h, open circuit test), and the high-temperature demagnetization rate was 57.28%. Therefore, it is impossible to obtain low-cost, high-temperature-resistant rapid-quenching permanent magnet materials using conventional cost-reduction methods. Although comparative examples 3 and 4 obtained higher Hcj at 20℃, because the Curie temperature of CeFeB is relatively low, the Hcj of the rapid-quenching permanent magnet material drops sharply after 200℃, resulting in the inability of the permanent magnet material to achieve high temperature resistance.

[0076] In order to improve the Curie temperature and high temperature resistance of the quick-quenching permanent magnet material, a conventional method is to use Co instead of Fe. Comparative Example 5 is based on Comparative Example 4, using 2.2at% Co to replace Fe. After substitution, the Hcj of the quick-quenching permanent magnet material at 20°C is 11.71kOe, but the Hcj at 250°C is only 2.03kOe. The bonded NdFeB magnet with a size of Φ10×10mm made of this material was subjected to a high-temperature demagnetization test (conditions: 250°C×2h, open circuit test), and its high-temperature demagnetization rate was 52.89%. Therefore, the arbitrary addition of Co cannot solve the problem that Ce-containing quick-quenching permanent magnet materials cannot withstand high temperatures.

[0077] Based on this, this embodiment systematically studies the total rare earth content, the amount of Ce substituted for Nd / PrNd, the Zr content, the Nb content, and the Co content to obtain a low-cost, high-temperature-resistant permanent magnet material containing Ce. In this low-cost, high-temperature-resistant permanent magnet material containing Ce, by limiting the range of the total rare earth content and the Ce content, and adding Zr or Nb or Zr and Nb in proportion to the total rare earth content and the Ce content when necessary, the Hcj of the rapid quenching permanent magnet material at room temperature is ensured; by adding Co in proportion to the Ce content, the Hcj of the rapid quenching permanent magnet material at high temperature is ensured.

[0078] A low-cost, high-temperature-resistant permanent magnetic material containing Ce, whose molecular formula is:

[0079] (Nd x Pr 1-x ) a Ce b Co d Zr e1 Nb f1 Fe g B h ;

[0080] The relationship between total rare earth content and Hcj, high temperature resistance and cost: In Ce-containing rapid quenching permanent magnet materials, too low total rare earth content will cause the rapid quenching permanent magnet materials to fail to meet the requirements of Hcj and high temperature resistance; too high total rare earth content will reduce the remanence of the magnet and increase the material cost. Therefore, in Ce-containing rapid quenching permanent magnet materials, in order to avoid too low Hcj, the total rare earth content should be guaranteed not to be lower than RE:Fe:B=2:14:1, that is, 11.8at%; in order to avoid too high cost and too low Br, the total rare earth content should be limited to within 13.5at%.

[0081] Based on this, the total rare earth content of low-cost, high-temperature-resistant permanent magnet materials containing Ce is in the range of:

[0082] 11.8≤a+b≤13.5;

[0083] In order to avoid low Hcj, the total rare earth content can be appropriately increased. Preferably, the total rare earth content ranges from:

[0084] 12.2≤a+b≤13.5;

[0085] Relationship between Ce content, Hcj and high temperature resistance: In Ce-containing quick-quenching permanent magnet materials, too high Ce content will lead to too low Hcj of quick-quenching permanent magnet materials, which cannot meet the requirements of high temperature resistance. In addition, the higher the Ce content, the higher the Co content, Zr content and Nb content that need to be added to ensure Hcj, and the higher the material cost. Therefore, according to actual conditions, the addition amount of Ce can be limited to 5.5at%, 6.0at%, 6.5at%, 7.0at%, 7.5at%, 8.0at%, 8.5at%, 9.0at%, 9.5at%, 10.0at%.

[0086] Based on this, the Ce content range of low-cost and high-temperature-resistant permanent magnetic materials containing Ce is:

[0087] 0<b≤10.0;

[0088] The more Ce content is added, the more obvious the cost advantage is. Therefore, according to the actual situation, the amount of Ce added can reach 0.5at%, 1.0at%, 1.5at%, 2.0at%, 2.5at%, 3.0at%, 3.5at%, 4.0at%, 4.5at%, 5.0at% or more. Preferably, the range of Ce content is:

[0089] 2.3≤b≤5.6;

[0090] Relationship between Co content and Ce content: The role of Co in the rapid quenching permanent magnet material is to resist the deterioration of CeFeB on the high temperature Hcj of the rapid quenching permanent magnet material. Therefore, the content of Co is closely related to the content of Ce. The higher the Ce content, the higher the amount of Co added. Therefore, the content of Co needs to correspond to the content of Ce.

[0091] Based on this, the Co content range of low-cost and high-temperature resistant permanent magnetic materials containing Ce is:

[0092] 0<d≤10.0;

[0093] Preferably, the range of Co content is:

[0094] 2.3≤d≤5.6;

[0095] The role of Nb and Zr in the rapid quenching permanent magnet material is the same, but the degree of their influence on the Hcj of the rapid quenching permanent magnet material is different. These two elements can be added separately or at the same time.

[0096] When Zr is added alone, the relationship between the Zr content and the total rare earth content and Ce content: The substitution of Ce for Nd not only causes the deterioration of the high-temperature Hcj of the quick-quenching permanent magnet material, but also causes the deterioration of the room-temperature Hcj of the quick-quenching permanent magnet material. At the same time, the total rare earth content will also affect the Hcj of the quick-quenching permanent magnet material. The higher the total rare earth content, the higher the Hcj of the quick-quenching permanent magnet material; the lower the total rare earth content, the lower the Hcj of the quick-quenching permanent magnet material. By adding Zr, the Hcj of the quick-quenching permanent magnet material at room temperature can be improved. Therefore, the higher the Ce content, the more Zr needs to be added; the lower the total rare earth content, the more Zr needs to be added. Therefore, according to actual conditions, the amount of Zr added can be limited to 0.5at%, 1.0at%, 1.5at%, 2.0at%, 2.5at%, 3.0at%, 3.5at%, 4.0at%, 4.5at%, 5.0at%, 5.5at%, 6.0at%, 6.5at%, 7.0at%, 7.5at%, 8.0at%, 8.5at%, 9.0at%.

[0097] Based on this, the Zr content range of low-cost and high-temperature resistant permanent magnetic materials containing Ce is:

[0098] 0≤e1≤9.0;

[0099] At the same time, in order to avoid the high cost of rapid quenching permanent magnet materials and too low Br, the total amount of Zr added should also be controlled. Therefore, preferably,

[0100] 0≤e1≤6.0;

[0101] Further limiting the content of Zr can ensure that the Hcj of the Ce-containing rapid quenching permanent magnet material at 20°C is ≥ 9.9 kOe. Preferably, when ((a+b)×(0.5×a+0.09×b)-(9.3×a+1.68×b)+(50×a+13×b) / (a+b))<9.9, the Zr content satisfies:

[0102] e1≥(9.9-((a+b)×(0.5×a+0.09×b)-(9.3×a+1.68×b)+(50×a+13×b) / (a+b)))×0.9;

[0103] Further limiting the content of Zr can ensure that the Hcj of the Ce-containing rapid quenching permanent magnet material at 20°C is ≥11kOe. Preferably, when ((a+b)×(0.5×a+0.09×b)-(9.3×a+1.68×b)+(50×a+13×b) / (a+b))<11, the Zr content satisfies:

[0104] e1≥(11-((a+b)×(0.5×a+0.09×b)-(9.3×a+1.68×b)+(50×a+13×b) / (a+b)))×0.9;

[0105] When Nb is added alone, the higher the Ce content, the more Nb needs to be added; the lower the total rare earth content, the more Nb needs to be added. At the same time, in order to avoid the high cost of rapid quenching permanent magnet materials and too low Br, the total amount of Nb added should also be controlled. Therefore, according to actual conditions, the amount of Nb added can be limited to 0.5at%, 1.0at%, 1.5at%, 2.0at%, 2.5at%, 3.0at%, 3.5at%, 4.0at%, 4.5at%, 5.0at%.

[0106] Based on this, the range of Nb content in low-cost, high-temperature-resistant permanent magnetic materials containing Ce is:

[0107] 0≤f1≤5.0;

[0108] At the same time, in order to avoid the high cost of rapid quenching permanent magnet materials and too low Br, the total amount of Nb added should also be controlled. Therefore, preferably,

[0109] 0≤f1≤2.0;

[0110] Further limiting the content of Nb can ensure that the Hcj of the Ce-containing rapid quenching permanent magnet material at 20°C is ≥ 9.9 kOe. Preferably, when ((a+b)×(0.5×a+0.09×b)-(9.3×a+1.68×b)+(50×a+13×b) / (a+b))<9.9, the Nb content satisfies:

[0111] f1≥(9.9-((a+b)×(0.5×a+0.09×b)-(9.3×a+1.68×b)+(50×a+13×b) / (a+b)))×0.7;

[0112] Further limiting the content of Nb can ensure that the Hcj of the Ce-containing rapid quenching permanent magnet material at 20°C is ≥11kOe. Preferably, when ((a+b)×(0.5×a+0.09×b)-(9.3×a+1.68×b)+(50×a+13×b) / (a+b))<11, the Nb content satisfies:

[0113] f1≥(11-((a+b)×(0.5×a+0.09×b)-(9.3×a+1.68×b)+(50×a+13×b) / (a+b)))×0.7;

[0114] When Zr and Nb are added simultaneously, the contents of Zr and Nb can be converted to each other, 1 at% of Zr corresponds to 0.78 at% of Nb.

[0115] The above-mentioned low-cost and high-temperature-resistant permanent magnetic material containing Ce has a Hcj≥9.9kOe at 20°C and a Hcj≥3kOe at 250°C.

[0116] Preferably, the low-cost and high-temperature-resistant permanent magnetic material containing Ce has a Hcj≥11 kOe at 20°C.

[0117] The ability of the quick-quenching permanent magnet material to withstand high temperatures can be evaluated not only by measuring the Hcj of the permanent magnet material at high temperatures, but also by the high-temperature demagnetization test of the permanent magnet material. The steps of the high-temperature demagnetization test are: the quick-quenching permanent magnet material is manufactured into a permanent magnet of a specific size: the permanent magnet is saturated and then baked under specific high temperature conditions for a specific time: the magnetic flux before and after the permanent magnet is baked is measured and the magnetic flux attenuation rate is calculated. The calculated magnetic flux attenuation rate is the high-temperature demagnetization of the quick-quenching permanent magnet material at the test temperature and time. The specific steps of the high-temperature demagnetization test in this study are: the quick-quenching permanent magnet material is manufactured into a bonded NdFeB magnet of Ф10x10mm; the axial two-pole saturation magnetization of the bonded NdFeB magnet of Ф10x10mm is performed and the magnetic flux is measured: the magnet is baked at 250℃, and there is no magnetic conductive material around the magnet during baking, and the baking time is 2 hours: the magnetic flux is measured again after the magnet is cooled to room temperature: the attenuation ratio of the magnetic flux of the magnet after baking is calculated, which is the high-temperature demagnetization rate at 250℃.

[0118] The normal working temperature of conventional quick-quenching permanent magnetic materials is about 100°C; the normal working temperature of high-temperature resistant quick-quenching permanent magnetic materials is about 120°C. At normal working temperature, quick-quenching permanent magnetic materials can ensure long-term magnetic properties. Therefore, if a short-term high-temperature demagnetization test is performed on the quick-quenching permanent magnetic material at normal working temperature, it is impossible to evaluate whether the material has the ability to withstand high temperatures. At the same time, in the process of manufacturing the quick-quenching permanent magnetic material into a magnet or a magnet assembly, or in the subsequent assembly process of the magnet or magnet assembly, the magnet may need to withstand higher temperatures, typically including: injection molding process, welding process, etc. In the injection molding process or welding process, the temperature that the magnetized magnet needs to withstand for a short time may reach above 250°C. Therefore, to determine whether the quick-quenching permanent magnetic material can withstand high temperatures, it is necessary to test and evaluate its Hcj at 250°C and high-temperature demagnetization rate at 250°C.

[0119] Theoretically, the quick-quenching permanent magnet material must be able to withstand a high temperature of 250°C. From the demagnetization curve, it must be ensured that there is basically no inflection point on the BH curve at 250°C. According to the Br, Br temperature coefficient and reversible magnetic permeability of the quick-quenching permanent magnet material, when Hcj≥3kOe at 250°C, it can be ensured that there is basically no inflection point on the BH curve at 250°C. This is also the fundamental reason why the above-mentioned Ce-containing quick-quenching permanent magnet material can meet the high temperature resistance requirements.

[0120] In the actual application process, the high temperature demagnetization test is used for evaluation. The high temperature demagnetization test conditions are designed as follows: 250℃×2h, open circuit test.

[0121] The high-temperature demagnetization rate of the bonded NdFeB magnet with a size of Φ10×10mm manufactured by the above-mentioned low-cost and high-temperature-resistant permanent magnetic material containing Ce is ≤20% (the high-temperature demagnetization test conditions are: 250°C×2h, open circuit test).

[0122] Preferably, the high temperature demagnetization rate of the bonded NdFeB magnet with a size of Φ10×10mm manufactured by the above-mentioned low-cost and high temperature resistant permanent magnetic material containing Ce is ≤20% (high temperature demagnetization test conditions are: 250°C×2h, open circuit test).

[0123] Examples 1 to 8 are examples of low-cost, high-temperature-resistant permanent magnet materials obtained based on research; Comparative Examples 6 to 7 are comparative examples given based on research. It can be seen from Examples 1 to 8 that by adjusting the content of total rare earth, Ce, Co, Zr and Nb, the Hcj of the rapid quenching permanent magnet material at 20°C is guaranteed to be greater than 10kOe and Hcj at 250°C is guaranteed to be greater than 3kOe, thereby ensuring that the bonded NdFeB magnet with a size of Φ10×10mm manufactured using the material has a high-temperature demagnetization rate of ≤20% (high-temperature demagnetization test conditions are: 250°C×2h, open circuit test).

[0124] It can also be seen from Examples 1 to 8 that the atomic percentage of Co in the low-cost high-temperature-resistant permanent magnetic material is close to the atomic percentage of Ce. Therefore, when the content of Co exceeds the content of Ce, the high temperature-resistant requirement of the Ce-containing rapid quenching permanent magnetic material can be better guaranteed.

[0125] Based on this, preferably, the Co content satisfies:

[0126] d ≥ b;

[0127] 2. Low-cost high-temperature resistant permanent magnetic materials containing La

[0128] The use of La substitution will lead to a decrease in the Hcj of the quick-quenching permanent magnet material, but La substitution will not cause a serious deterioration in the Hcj of the quick-quenching permanent magnet material above 200°C like Ce. Therefore, it is necessary to limit the total rare earth content and the amount of La substitution, and under some conditions, add Zr or Nb or Zr and Nb to ensure the Hcj of the low-cost high-temperature resistant permanent magnet material containing La at 20°C.

[0129] Based on this, the molecular formula of the low-cost and high-temperature-resistant permanent magnetic material containing La is:

[0130] (Nd x Pr 1-x ) a La c Zr e2 Nb f2 Fe g B h ;

[0131] The relationship between total rare earth content and Hcj, high temperature resistance and cost: In La-containing rapid quenching permanent magnet materials, too low total rare earth content will cause the rapid quenching permanent magnet materials to fail to meet the requirements of Hcj and high temperature resistance; too high total rare earth content will reduce the remanence of the magnet and increase the material cost. At the same time, because the substitution of La will not cause the Hcj of the rapid quenching permanent magnet materials above 200°C to deteriorate seriously like Ce, the Hcj of the La-containing rapid quenching permanent magnet materials at 20°C only needs to meet ≥9.5kOe to meet the requirements of high temperature resistance. Therefore, in La-containing rapid quenching permanent magnet materials, the lower limit of the total rare earth content can be relaxed to 11.4at%; in order to avoid excessively high costs and too low Br, the total rare earth content should be limited to within 13.5at%.

[0132] Based on this, the total rare earth content of La-containing low-cost, high-temperature-resistant permanent magnetic materials ranges from:

[0133] 11.4≤a+c≤13.5;

[0134] In order to avoid low Hcj, the total rare earth content can be appropriately increased. Preferably, the total rare earth content ranges from:

[0135] 11.8≤a+c≤13.5;

[0136] Relationship between La content, Hcj and high temperature resistance: In La-containing quick-quenching permanent magnet materials, higher La content will lead to a decrease in Hcj of quick-quenching permanent magnet materials. In addition, the higher the La content, the higher the Zr content and Nb content that need to be added to ensure Hcj, and the higher the material cost. Therefore, according to actual conditions, the amount of La added can be limited to 2.5at%, 3.0at%, 3.5at%, 4.0at%, 4.5at%, 5.0at%.

[0137] Based on this, the La content range of La-containing low-cost and high-temperature resistant permanent magnetic materials is:

[0138] 0<c≤5.0;

[0139] The more La content is added, the more obvious the cost advantage is. Therefore, according to the actual situation, the amount of La added can reach 0.5at%, 1.0at%, 1.5at%, 2.0at%, 2.5at% or more. Preferably, the range of La content is:

[0140] 0.5≤c≤2.9;

[0141] The role of Nb and Zr in the rapid quenching permanent magnet material is the same, but the degree of their influence on the Hcj of the rapid quenching permanent magnet material is different. These two elements can be added separately or at the same time.

[0142] When Zr is added alone, the relationship between the Zr content and the total rare earth content and La content: La's substitution for Nd not only causes the high-temperature Hcj of the quick-quenching permanent magnet material to deteriorate, but also causes the room-temperature Hcj of the quick-quenching permanent magnet material to deteriorate. At the same time, the total rare earth content will also affect the Hcj of the quick-quenching permanent magnet material. The higher the total rare earth content, the higher the Hcj of the quick-quenching permanent magnet material; the lower the total rare earth content, the lower the Hcj of the quick-quenching permanent magnet material. By adding Zr, the Hcj of the quick-quenching permanent magnet material at room temperature can be improved. Therefore, the higher the La content, the more Zr needs to be added; the lower the total rare earth content, the more Zr needs to be added. Therefore, according to actual conditions, the amount of Zr added can be limited to 0.5at%, 1.0at%, 1.5at%, 2.0at%, 2.5at%, 3.0at%, 3.5at%, 4.0at%, 4.5at%, 5.0at%, 5.5at%, 6.0at%, 6.5at%, 7.0at%, 7.5at%, 8.0at%, 8.5at%, 9.0at%.

[0143] Based on this, the Zr content range of La-containing low-cost high-temperature resistant permanent magnetic materials is:

[0144] 0≤e2≤9.0;

[0145] At the same time, in order to avoid the high cost of rapid quenching permanent magnet materials and too low Br, the total amount of Zr added should also be controlled. Therefore, preferably,

[0146] 0≤e2≤6.0;

[0147] Further limiting the content of Zr can ensure that the Hcj of the La-containing rapid quenching permanent magnet material at 20°C is ≥ 9.5 kOe. Preferably, when ((a+c)×(0.5×a+0.05×c)-(9.3×a+0.93×c)+(50×a+10.7×c) / (a+c))<9.5, the Zr content satisfies:

[0148] e2≥(9.5-((a+c)×(0.5×a+0.05×c)-(9.3×a+0.93×c)+(50×a+10.7×c) / (a+c)))×0.9;

[0149] Further limiting the content of Zr can ensure that the Hcj of the La-containing rapid quenching permanent magnet material at 20°C is ≥ 9.9 kOe. Preferably, when ((a+c)×(0.5×a+0.05×c)-(9.3×a+0.93×c)+(50×a+10.7×c) / (a+c))<9.9, the Zr content satisfies:

[0150] e2≥(9.9-((a+c)×(0.5×a+0.05×c)-(9.3×a+0.93×c)+(50×a+10.7×c) / (a+c)))×0.9;

[0151] Further limiting the content of Zr can ensure that the Hcj of the La-containing rapid quenching permanent magnet material at 20°C is ≥ 11kOe. Preferably, when ((a+c)×(0.5×a+0.05×c)-(9.3×a+0.93×c)+(50×a+10.7×c) / (a+c))<11, the Zr content satisfies:

[0152] e2≥(11-((a+c)×(0.5×a+0.05×c)-(9.3×a+0.93×c)+(50×a+10.7×c) / (a+c)))×0.9;

[0153] When Nb is added alone, the higher the La content, the more Nb needs to be added; the lower the total rare earth content, the more Nb needs to be added. At the same time, in order to avoid the high cost of rapid quenching permanent magnet materials and too low Br, the total amount of Nb added should also be controlled. Therefore, according to actual conditions, the amount of Nb added can be limited to 0.5at%, 1.0at%, 1.5at%, 2.0at%, 2.5at%, 3.0at%, 3.5at%, 4.0at%, 4.5at%, 5.0at%.

[0154] Based on this, the range of Nb content in low-cost, high-temperature-resistant permanent magnetic materials containing La is:

[0155] 0≤f2≤5.0;

[0156] At the same time, in order to avoid the high cost of rapid quenching permanent magnet materials and too low Br, the total amount of Nb added should also be controlled. Therefore, preferably,

[0157] 0≤f2≤2.0;

[0158] Further limiting the content of Nb can ensure that the Hcj of the La-containing rapid quenching permanent magnet material at 20°C is ≥ 9.5 kOe. Preferably, when ((a+c)×(0.5×a+0.05×c)-(9.3×a+0.93×c)+(50×a+10.7×c) / (a+c))<9.5, the Nb content satisfies:

[0159] f2≥(9.5-((a+c)×(0.5×a+0.05×c)-(9.3×a+0.93×c)+(50×a+10.7×c) / (a+c)))×0.7;

[0160] Further limiting the content of Nb can ensure that the Hcj of the La-containing rapid quenching permanent magnet material at 20°C is ≥ 9.9 kOe. Preferably, when ((a+c)×(0.5×a+0.05×c)-(9.3×a+0.93×c)+(50×a+10.7×c) / (a+c))<9.9, the Nb content satisfies:

[0161] f2≥(9.9-((a+c)×(0.5×a+0.05×c)-(9.3×a+0.93×c)+(50×a+10.7×c) / (a+c)))×0.7;

[0162] Further limiting the content of Nb can ensure that the Hcj of the La-containing rapid quenching permanent magnet material at 20°C is ≥ 11kOe. Preferably, when ((a+c)×(0.5×a+0.05×c)-(9.3×a+0.93×c)+(50×a+10.7×c) / (a+c))<11, the Nb content satisfies:

[0163] f2≥(11-((a+c)×(0.5×a+0.05×c)-(9.3×a+0.93×c)+(50×a+10.7×c) / (a+c)))×0.7;

[0164] When Zr and Nb are added simultaneously, the contents of Zr and Nb can be converted to each other, 1 at% of Zr corresponds to 0.78 at% of Nb.

[0165] The above-mentioned La-containing low-cost and high-temperature-resistant permanent magnetic material has a Hcj≥9.5kOe at 20°C and a Hcj≥3kOe at 250°C.

[0166] Preferably, the low-cost and high-temperature-resistant permanent magnetic material containing La has a Hcj≥9.9 kOe at 20°C.

[0167] Preferably, the low-cost and high-temperature-resistant permanent magnetic material containing La has a Hcj≥11 kOe at 20°C.

[0168] The high-temperature demagnetization rate of the bonded NdFeB magnet with a size of Φ10×10mm manufactured by the above-mentioned low-cost and high-temperature resistant permanent magnetic material containing La is ≤20% (high-temperature demagnetization test conditions: 250°C×2h, open circuit test).

[0169] Preferably, the high temperature demagnetization rate of the bonded NdFeB magnet with a size of Φ10×10mm manufactured by the above-mentioned low-cost and high temperature resistant permanent magnetic material containing La is ≤20% (high temperature demagnetization test conditions are: 250°C×2h, open circuit test).

[0170] Example 9 is an example of a low-cost, high-temperature-resistant permanent magnet material obtained based on research. It can be seen that by adjusting the content of total rare earth, La, Zr and Nb, the rapid quenching permanent magnet material is guaranteed to have a high Hcj at both 20°C and 250°C, thereby ensuring that the bonded NdFeB magnet with a size of Φ10×10mm manufactured using the material has a lower high-temperature demagnetization (conditions: 250°C×2h, open circuit test).

[0171] 3. Low-cost high-temperature resistant permanent magnetic material containing LaCe

[0172] The total rare earth content and the content of each element of the low-cost high-temperature resistant material containing LaCe will be between the low-cost high-temperature resistant permanent magnetic material containing La and the low-cost high-temperature resistant permanent magnetic material containing Ce. Its molecular formula is:

[0173] (Nd x Pr 1-x ) a Ce b La c Co d Zr e3 Nbf3 Fe g B h ;

[0174] Combining the analysis process of low-cost high-temperature resistant permanent magnet materials containing Ce and low-cost high-temperature resistant permanent magnet materials containing Ce, it can be seen that the range of total rare earth content is:

[0175] 11.4≤a+b+c≤13.5;

[0176] Preferably, the total rare earth content ranges from:

[0177] 11.8≤a+b+c≤13.5;

[0178] The range of Ce content is:

[0179] 0<b≤10.0;

[0180] Preferably, the range of Ce content is:

[0181] 2.3≤b≤5.6;

[0182] The range of La content is:

[0183] 0<c≤5.0;

[0184] Preferably, the range of La content is:

[0185] 0.5≤c≤2.9;

[0186] The range of Co content is:

[0187] 0<d≤10.0;

[0188] Preferably, the range of Co content is:

[0189] 2.3≤d≤5.6;

[0190] Preferably, the Co content satisfies:

[0191] d ≥ b;

[0192] The range of Zr content is:

[0193] 0≤e3≤9.0;

[0194] Preferably, the range of Zr content is:

[0195] 0≤e3≤6.0;

[0196] Preferably, when ((a+b+c)×(0.5×a+0.09×b+0.05×c)-(9.3×a+1.68×b+0.93×c)+(50×a+13×b+10.7×c) / (a+b+c))<9.5, the Zr content satisfies:

[0197] e3≥(9.5-((a+b+c)×(0.5×a+0.09×b+0.05×c)-(9.3×a+1.68×b+0.93×c)+(50×a+13×b+10.7×c) / (a+b+c)))×0.9;

[0198] Preferably, when ((a+b+c)×(0.5×a+0.09×b+0.05×c)-(9.3×a+1.68×b+0.93×c)+(50×a+13×b+10.7×c) / (a+b+c))<9.9, the Zr content satisfies:

[0199] e3≥(9.9-((a+b+c)×(0.5×a+0.09×b+0.05×c)-(9.3×a+1.68×b+0.93×c)+(50×a+13×b+10.7×c) / (a+b+c)))×0.9;

[0200] Preferably, when ((a+b+c)×(0.5×a+0.09×b+0.05×c)-(9.3×a+1.68×b+0.93×c)+(50×a+13×b+10.7×c) / (a+b+c))<11, the Zr content satisfies:

[0201] (11-((a+b+c)×(0.5×a+0.09×b+0.05×c)-(9.3×a+1.68×b+0.93×c)+(50×a+13×b+10.7×c) / (a+b+c)))×0.9;

[0202] The range of Nb content is:

[0203] 0≤f3≤5.0;

[0204] Preferably,

[0205] 0≤f3≤2.0;

[0206] Preferably, when ((a+b+c)×(0.5×a+0.09×b+0.05×c)-(9.3×a+1.68×b+0.93×c)+(50×a+13×b+10.7×c) / (a+b+c))<9.5, the Nb content satisfies:

[0207] f3≥(9.5-((a+b+c)×(0.5×a+0.09×b+0.05×c)-(9.3×a+1.68×b+0.93×c)+(50×a+13×b+10.7×c) / (a+b+c)))×0.7;

[0208] Preferably, when ((a+b+c)×(0.5×a+0.09×b+0.05×c)-(9.3×a+1.68×b+0.93×c)+(50×a+13×b+10.7×c) / (a+b+c))<9.9, the Nb content satisfies:

[0209] f3≥(9.9-((a+b+c)×(0.5×a+0.09×b+0.05×c)-(9.3×a+1.68×b+0.93×c)+(50×a+13×b+10.7×c) / (a+b+c)))×0.7;

[0210] Preferably, when ((a+b+c)×(0.5×a+0.09×b+0.05×c)-(9.3×a+1.68×b+0.93×c)+(50×a+13×b+10.7×c) / (a+b+c))<11, the Nb content satisfies:

[0211] f3≥(11-((a+b+c)×(0.5×a+0.09×b+0.05×c)-(9.3×a+1.68×b+0.93×c)+(50×a+13×b+10.7×c) / (a+b+c)))×0.7;

[0212] The above-mentioned low-cost and high-temperature-resistant permanent magnetic material containing LaCe has a Hcj≥9.5kOe at 20°C and a Hcj≥3kOe at 250°C.

[0213] Preferably, the low-cost and high-temperature-resistant permanent magnetic material containing LaCe has a Hcj≥9.9 kOe at 20°C.

[0214] Preferably, the low-cost and high-temperature-resistant permanent magnetic material containing LaCe has a Hcj≥11 kOe at 20°C.

[0215] The high-temperature demagnetization rate of the bonded NdFeB magnet with a size of Φ10×10mm manufactured by the above-mentioned low-cost and high-temperature-resistant permanent magnetic material containing LaCe is ≤20% (the high-temperature demagnetization test conditions are: 250°C×2h, open circuit test).

[0216] Preferably, the high temperature demagnetization rate of the bonded NdFeB magnet with a size of Φ10×10mm manufactured by the above-mentioned low-cost and high temperature resistant permanent magnetic material containing LaCe is ≤20% (high temperature demagnetization test conditions are: 250°C×2h, open circuit test).

[0217] Embodiment 10, Embodiment 11 and Embodiment 12 are examples of low-cost, high-temperature-resistant permanent magnetic materials obtained based on research. Figure 1 is the demagnetization curve of the rapid quenching permanent magnet material of Example 12, Figure 2 This is the demagnetization curve of the bonded NdFeB made of the quick-quenching permanent magnet material of Example 12. It can be seen that by adjusting the content of total rare earth, Ce, La, Co, Zr and Nb, the quick-quenching permanent magnet material is guaranteed to have high Hcj at both 20°C and 250°C, and BH can be kept as a straight line at 250°C, thereby ensuring that the bonded magnet with a size of Φ10×10mm made of this material has a lower high-temperature demagnetization (conditions: 250°C×2h, open circuit test).

[0218] At the same time, through Figure 2 It can be seen that the key to the high temperature resistance of the low-cost and high-temperature-resistant permanent magnetic material of the present invention is that Hcj remains equivalent to Br at 250°C, that is, at 250°C, the bonded magnet made of the low-cost and high-temperature-resistant permanent magnetic material of the present invention, when Br is 3-4kGs, Hcj is still above 3kOe.

[0219] Table 1

[0220]

[0221] The present invention provides a low-cost high-temperature resistant permanent magnetic material, the general structural formula of which is (Nd x Pr 1-x ) a Ce b La c Co d Zr e Nb f Fe g B h; Among them, 0≤x≤1, 11.4≤a+b+c≤13.5, 0<b+c, 0≤b≤10.0, 0≤c≤5.0, 0≤d≤10.0, 0≤e≤9.0, 0≤f≤5.0, 4.8≤h≤7.2, a+b+c+d+e+f+g+h equals 100. Through systematic research on direct substitution of La or Ce or LaCe for Nd or PrNd, and addition of trace elements Co, Zr and Nb, the permanent magnetic material has high coercivity at room temperature or high temperature, and the magnet prepared with the permanent magnetic material has low demagnetization rate at high temperature, showing the characteristics of low cost and high temperature resistance. Specifically, the Hcj value of the permanent magnetic material at 20°C can reach more than 9.5kOe, and at the same time, the Hcj value at 250°C can still reach more than 3.0kOe, and the high-temperature demagnetization rate of the bonded NdFeB magnet with a size of Φ10×10mm made of permanent magnetic material can be less than 20%, achieving unexpected technical effects.

[0222] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A low-cost and high-temperature-resistant permanent magnetic material, characterized in that: Comprising the composition shown in formula (I), (Nd x Prof 1-x ) a Ce b Day c Co d Zr e No f Feb g B h (I); Among them, 0≤x≤1, 11.4≤a+b+c≤13.5, 0<b+c, 0≤b≤10.0, 0≤c≤5.0, 0≤d≤10.0, 0≤e≤9.0, 0≤f≤5.0, 4.8≤h≤7.2, a+b+c+d+e+f+g+h equals 100.

2. The low-cost and high-temperature-resistant permanent magnetic material according to claim 1, characterized in that: The low-cost, high-temperature-resistant permanent magnetic material has an Hcj value of more than 9.5 kOe at 20°C and a Hcj value of more than 3.0 kOe at 250°C. The high-temperature demagnetization rate of the bonded magnet with a size of Φ10×10 mm manufactured from the low-cost, high-temperature-resistant permanent magnetic material is less than 20%.

3. The low-cost and high-temperature-resistant permanent magnetic material according to claim 1, characterized in that: When b>0, d>0.

4. The low-cost and high-temperature-resistant permanent magnetic material according to claim 3 is characterized in that: 11.8≤a+b+c≤13.5, 0≤b≤5.6, 0≤c≤2.9, b≤d.

5. The low-cost and high-temperature-resistant permanent magnetic material according to claim 1, characterized in that: When e>0, f=0, e satisfies formula (II): (m-((a+b+c)×(0.5×a+0.09×b+0.05×c)-(9.3×a+1.68×b+0.93×c)+(50×a+13×b+10.7×c) / (a+b+c)))×0.9≤e≤9.0(II); When f>0, e=0, f satisfies formula (III): (m-((a+b+c)×(0.5×a+0.09×b+0.05×c)-(9.3×a+1.68×b+0.93×c)+(50×a+13×b+10.7×c) / (a+b+c)))×0.7≤f≤5.0(III); Among them, m is 9.9 to 15.

5.

6. The low-cost and high-temperature-resistant permanent magnetic material according to claim 5, characterized in that: When e>0, f>0, e is converted to f or f is converted to e according to e:f=1:0.78, and the converted e satisfies formula (II) or f satisfies formula (III).

7. A method for preparing a low-cost, high-temperature-resistant permanent magnetic material according to any one of claims 1 to 6, comprising the following steps: Step 1, weighing various raw materials according to the proportion of formula (I), mixing the weighed raw materials, and smelting them into alloy ingots; Step 2, melting the alloy ingot obtained in step 1 and rapidly cooling it into a nano alloy strip; Step 3: crushing the alloy strips obtained in step 2 to obtain low-cost and high-temperature-resistant permanent magnetic materials.

8. A magnet, characterized in that: The magnet is made of the low-cost and high-temperature-resistant permanent magnetic material described in any one of claims 1-6.

9. A device, characterized in that The device is made by processing the magnet according to claim 8.

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