MANUFACTURING METHOD FOR Nd-Fe-B BASED MAGNETIC MATERIAL

Abstract

To provide a new method for manufacturing Nd-Fe-B based magnetic materials of special shapes and extreme sizes.SOLUTION: (Step 1) At least one surface of an FeaGb metal piece is coated with one layer of a rare earth compound RexMyBz coating layer, (Step 2) the FeaGb metal piece coated with the rare earth compound RexMyBz coating layer is stacked to a predetermined thickness in a mold, and after stacking, at least one layer of rare earth compound RexMyBz coating layer is present between two adjacent layers of the FeaGb metal piece, and (Step 3) the stacked FeaGb metal piece is pressed and subjected to a diffusion treatment in a vacuum to obtain an Nd-Fe-B based magnetic material.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention belongs to the technical field of manufacturing permanent magnetic materials, and particularly relates to a method for manufacturing Nd—Fe—B based magnetic materials. [Background technology]

[0002] Nd-Fe-B permanent magnetic materials are widely used in industrial and electronic technology fields. They can be classified into Nd-Fe-B sintered magnetic materials, Nd-Fe-B bonded magnetic materials, and Nd-Fe-B hot-pressed magnetic materials according to their manufacturing method, and the merits and demerits of each manufacturing method vary.

[0003] Chinese Patent Publication No. CN115083713A discloses an Nd-Fe-B sintered magnetic material and a method for producing the same. Specifically, the process involves first preparing Nd-Fe-B alloy flakes, then pulverizing the Nd-Fe-B alloy flakes to nanometer-scale to produce Nd-Fe-B powder. Finally, the Nd-Fe-B powder is oriented pressed, sintered, and aged to obtain the Nd-Fe-B magnetic material. However, this method involves a complex sintering process for producing Nd-Fe-B magnetic materials. Furthermore, nanometer-scale Nd-Fe-B powder is highly susceptible to oxidation and combustion, potentially increasing the risk of hazards during the manufacturing process. It is difficult to produce irregularly shaped Nd-Fe-B products (especially thin products) using the sintering method. Typically, a block of sintered Nd-Fe-B magnetic material is then machined into the desired shape, but this process results in material waste.

[0004] Chinese Patent Publication CN108538561A also discloses an Nd-Fe-B adhesive magnetic material and a method for manufacturing the same. Specifically, the process involves first mixing a thermosetting adhesive powder with an Nd-Fe-B powder to form a magnetic powder mixture, then pressing the magnetic powder mixture into a mold to form a magnetic base, and finally curing the mixture to obtain the Nd-Fe-B magnetic material. Adhesively formed Nd-Fe-B magnetic materials have a simple overall manufacturing process, low risk, and can be produced in a variety of shapes and sizes. However, adhesively formed Nd-Fe-B magnetic materials require a large amount of organic adhesive in the manufacturing process, which reduces the magnetic material's density, remanence, and mechanical properties. Furthermore, the presence of the organic adhesive prevents the adhesive magnetic material from being used in high-temperature environments.

[0005] Furthermore, Chinese Patent Publication CN110753978A discloses a thermally deformable magnetic material and a method for manufacturing the same. Specifically, the process involves rapidly cooling Nd-Fe-B alloy flakes, then pulverizing the alloy flakes and obtaining the Nd-Fe-B magnetic material through hot pressing and thermorheology. However, the production of Nd-Fe-B magnetic material through hot pressing is difficult, resulting in poor production efficiency and poor magnetic properties, making it difficult to manufacture products with unusual shapes and extreme sizes. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Chinese Patent CN115083713A Publication Publication [Patent Document 2] Chinese Patent CN108538561A Publication Publication [Patent Document 3] Chinese patent CN110753978A publication DISCLOSURE OF THE INVENTION [Problem to be solved by the invention]

[0007] In view of the above-mentioned problems of the conventional techniques, the present invention aims to provide a new method for producing Nd—Fe—B based magnetic materials of special shapes and extreme sizes by improving the manufacturing process of Nd—Fe—B based magnetic materials. [Means for solving the problem]

[0008] In order to achieve the above object, the present invention provides an Nd—Fe—B based magnetic material and a method for producing the same, (Step 1) Fe a G b At least one surface of the metal piece is coated with a layer of rare earth compound Re. x M y B z Covered with a coating layer, (Step 2) Adding the rare earth compound Re x M y B z The Fe coated with a coating layer a G b The metal pieces are stacked in a mold to a predetermined thickness, and the two adjacent layers of the Fe a G b At least one layer of the rare earth compound Re is provided between the metal pieces. x M y B z There is a coating layer, (Step 3) The Fe after lamination a G b The metal pieces are pressed and then subjected to a diffusion treatment in a vacuum to obtain Nd-Fe-B magnetic materials. Fe a G b In the metal pieces, Fe represents iron, G represents one or more of aluminum, titanium, copper, zinc, manganese, cobalt, nickel, niobium, molybdenum, zirconium, and chromium, and a and b represent mass percentages, 75%≦a≦100%, 0%≦b≦25%; The rare earth compound Re x M y B zIn the coating layer, Re is at least one of neodymium, praseodymium, cerium, lanthanum, terbium, dysprosium, and holmium, M is at least one of iron, aluminum, titanium, copper, zinc, manganese, cobalt, and gallium, and B is boron; x, y, and z represent mass percentages, and are characterized in that 70%≦x≦95%, 2%≦z≦4%, and y=1−xz.

[0009] In one embodiment, one layer of Fe a G b The mass of the metal piece M1 and one layer of Fe a G b Rare earth compound Re on metal strip x M y B z The ratio of the mass of the coating layer to the mass M2 is characterized by 40%≦M2 / M1≦80%.

[0010] In one embodiment, one layer of Fe a G b The thickness h1 of the metal piece is characterized in that 0.02 mm≦h1≦0.50 mm.

[0011] In one embodiment, the Fe a G b Thickness of metal pieces and rare earth compounds Re x M y B z The thickness h2 of the coating layer is characterized in that it satisfies the condition 0.04 mm≦h2≦80 mm.

[0012] In one embodiment, Fe a G b A layer of rare earth compound Re covering the surface of the metal piece x M y B z The coating layer is characterized by being formed by vacuum deposition, plasma spraying, or thermal spraying.

[0013] In one embodiment, Fe a G bThe metal pieces are stacked to form a block, tile, cylinder, or ring shape.

[0014] In one embodiment, the diffusion temperature in step 3 is 1000 to 1200° C., and the diffusion time is 0.5 to 10 hours. [Effects of the Invention]

[0015] The method for manufacturing Nd-Fe-B magnetic materials according to the present invention eliminates the need for flammable and dangerous nano-level rare earth Nd-Fe-B powder, improving the overall safety of the manufacturing process, and the absence of organic adhesives allows for improved remanence and operating temperature of the magnetic material. Furthermore, fewer manufacturing parameters are required throughout the manufacturing process, shortening the manufacturing cycle and enabling the direct production of products with various desired shapes, without the loss of material that occurs during machining.

[0016] Furthermore, as in one embodiment, by combining two types of laminates made of metal pieces with different components, it is possible to locally adjust the magnetic properties of the magnetic material and produce a magnetic material with a gradient distribution of magnetic properties, thereby providing a magnetic material that can ensure good anti-demagnetization properties even under special demagnetization environments. [Brief explanation of the drawings]

[0017] [Figure 1] A diagram showing a layer of rare earth compound RexMyBz coated on the surface of a FeaGb metal piece. [Figure 2] A diagram of FeaGb metal pieces coated with a rare earth compound RexMyBz coating layer stacked in a cylindrical shape. [Figure 3] A diagram of FeaGb metal pieces coated with a rare earth compound RexMyBz coating layer stacked in a tile shape. [Figure 4] A block-shaped stack of FeaGb metal pieces coated with a rare earth compound RexMyBz coating layer. [Figure 5] A diagram of a ring-shaped stack of FeaGb metal pieces coated with a rare earth compound RexMyBz coating layer. DETAILED DESCRIPTION OF THE INVENTION

[0018] Examples 1 to 6 of the present invention will be described below with reference to Figures 1 to 5. Each example is used only to interpret the present invention, and does not limit the configuration of the present invention.

[0019] Figure 1 shows Fe a G b A layer of rare earth compound Re is formed on the surface of the metal piece 1. x M y B z 2 is a diagram showing a schematic state in which the sheet is coated with the resin 2, and in the present invention, a plurality of sheets are stacked and pressed into a mille-feuille shape, and then subjected to a diffusion treatment.

[0020] Example 1 (Step 1) Fe a G b Metal ingots are smelted and pressed to produce Fe a G b Metal piece 1. In Example 1, Fe a G b Fe 90 The mass percentage of titanium was 2%, the mass percentage of nickel was 3%, and the mass percentage of zirconium was 5%, and Fe was deposited by thermal spraying. 90 A layer of rare earth compound Re is applied to the surface of the Ti2Ni3Zr5 metal piece. x M y B z In Example 1, the coating layer 2 was sprayed. x M y B z Nd 70 Al 3.8 Cu4Ga2Ti 2.2 Fe 16B2. Re is neodymium, M is aluminum, copper, gallium, titanium, and iron, and B is boron. x, y, and z are mass percentages, and in Example 1, x was 70% neodymium, y was 28% in total of aluminum (3.8%), copper (4%), gallium (2%), titanium (2.2%), and iron (16%), and z was 2% boron. One layer of Fe a G b Mass M1 of metal piece 1 and one layer of Fe a G b Rare earth compound Re on metal piece 1 x M y B z The ratio of the mass of the coating layer 2 to the mass M2 was set to M2 / M1=70%. a G b The thickness h1 of the metal piece 1 was set to h1=0.35 mm.

[0021] (Step 2) Rare earth compound Nd 70 Al 3.8 Cu4Ga2Ti 2.2 Fe 16 Fe with B2 coating layer 90 The Ti2Ni3Zr5 metal piece 1 was spirally formed into a cylindrical shape so that it could fit into a cylindrical mold with a length of 20 mm and an inner diameter of 60 mm. a The thickness h2 of the Gb metal piece 1 is set to h2 = 30 mm, the diameter of the cylinder is set to 60 mm, and the two adjacent layers of Fe a Between the Gb metal pieces 1, there is at least one layer of rare earth compound Re x M y B z The coating layer 2 was present. A specific example of the mold is shown in Figure 2. Reference numeral 10 denotes an upper mold for a cylindrical press, reference numeral 11 denotes a lower mold for a cylindrical press, and the arrows indicate the direction of stress.

[0022] (Step 3) Fe after lamination a G b The metal piece 1 was pressed and subjected to a diffusion treatment in a vacuum to produce a cylindrical Nd-Fe-B magnetic material with a diameter of 60 mm and a height of 20 mm. The diffusion temperature was 1100°C and the diffusion time was 5 hours.

[0023] To measure the magnetic properties of the completed cylindrical Nd-Fe-B magnetic material, it was cut into a columnar sample with a diameter of 10 mm and a height of 10 mm and measured at a temperature of 20°C ± 3°C. The measurement results are shown in Table 1.

[0024] From the above measurement results, it can be seen that the cylindrical magnetic body according to Example 1 has excellent magnetic properties, with a residual magnetic flux density Br of 10.87 kGs and a coercive force Hcj of 10.20 kOe.

[0025] Example 2 (Step 1) Fe a G b Metal ingots are smelted and pressed to produce Fe a In Example 2, the Fe a G b Fe 90 Cr9Al 0.5 Zn 0.5 G is an aggregate of chromium, aluminum, and zinc. a and b are mass percentages, with a being 90% and b being 10%. The mass percentage of chromium is 9%, the mass percentage of aluminum is 0.5%, and the mass percentage of zinc is 0.5%, and Fe is deposited by vacuum deposition. 90 Cr9Al 0。5 Zn 0。5 A layer of rare earth compound Re is formed on the surface of the metal piece 1. x M y B z Coating layer 2 was vapor-deposited. x M y B z Nd 72 Dy1Ho2Cu3Ti 0。3 Zn 0。2 Fe 19 B 2。5 Re is neodymium, dysprosium, and holmium, M is copper, titanium, zinc, and iron, and B is boron. x, y, and z are mass percentages, and in Example 2, x is 75% in total of neodymium (72%), dysprosium (1%), and holmium (2%), y is 22.5% in total of copper (3%), titanium (0.3%), zinc (0.2%), and iron (19%), and z is 2.5% of boron. One layer of Fe a Gb The mass M1 of metal piece 1 and one layer of Fe aRare earth compound Re on Gb metal piece 1 x M y B z The ratio of the mass of the coating layer 2 to the mass M2 was set to M2 / M1=80%. a The thickness h1 of the Gb metal piece 1 was set to h1=0.20 mm.

[0026] (Step 2) Rare earth compound Nd 72 Dy1Ho2Cu3Ti 0.3 Zn 0.2 Fe 19 B 2。5 Fe with coating layer 90 Cr9Al 0.5 Zn 0.5 The metal pieces were stacked in a semicircular mold with a length of 10 mm, a central angle of 180°, and a radius of 15 mm to form a tile shape. a The thickness h2 of the Gb metal piece 1 is set to h2 = 10 mm, and the thickness of the two adjacent layers of Fe a Between the Gb metal pieces 1, there is at least one layer of rare earth compound Re x M y B z The coating layer 2 was present. A specific example of the mold is shown in Figure 3. Reference numeral 5 denotes the lower mold for roof tile pressing, reference numeral 6 denotes the upper mold for roof tile pressing, and the arrows indicate the direction of stress.

[0027] (Step 3) Fe after lamination a The Gb metal piece 1 was pressed and subjected to a diffusion treatment in a vacuum to create a tile-shaped Nd-Fe-B magnetic material. The diffusion temperature was 1200°C and the diffusion time was 8 hours.

[0028] To measure the magnetic properties of the completed tile-shaped Nd-Fe-B magnetic material, it was cut into a columnar sample with a diameter of 10 mm and a height of 10 mm and measured at a temperature of 20°C ± 3°C. The measurement results are shown in Table 1.

[0029] From the above measurement results, it can be seen that the tile-shaped Nd—Fe—B magnetic material of Example 2 has excellent magnetic properties, with a residual magnetic flux density Br of 9.68 kGs and a coercive force Hcj of 10.35 kOe.

[0030] Example 3 (Step 1) Fe a G b Metal ingots are smelted and pressed to produce Fe a In Example 3, Fe a G b Fe 75 Mn3Cu1Ho2Co3Zr 10 Ni8. G is an aggregate of manganese, copper, holmium, cobalt, zirconium, and nickel. a and b are mass percentages, with a set to 75% and b set to 25%. The mass percentage of manganese is 3%, the mass percentage of copper is 1%, the mass percentage of holmium is 2%, the mass percentage of cobalt is 3%, the mass percentage of zirconium is 10%, and the mass percentage of nickel is 8%, and Fe is deposited by plasma spraying. 75 Mn3Cu1Ho2Co3Zr 10 A layer of rare earth compound Re is deposited on the surface of Ni8 metal piece 1. x M y B z In Example 3, the coating layer 2 was sprayed. x M y B z Pr 60 Ce 30 Cu 1.5 Mn 0。5 The composition was Ga1Fe4B3. Re is praseodymium and cerium, M is copper, manganese, gallium, and iron, and B is boron. x, y, and z are mass percentages. In Example 3, x is 90% of the total of praseodymium (60%) and cerium (30%), y is 7% of the total of copper (1.5%), manganese (0.5%), potassium (1%), and iron (4%), and z is 3% of boron. One layer of Fe a The mass of the Gb metal piece 1 is M1, and the mass of one layer of Fe a Rare earth compound Re on Gb metal piece 1 x M y B z The ratio of the mass of the coating layer 2 to the mass M2 was set to M2 / M1=60%. a The thickness h1 of the Gb metal piece 1 was set to h1=0.50 mm.

[0031] (Step 2) Rare earth compound Pr 60 Ce30 Cu 1.5 Mn 0。5 Fe with a Ga1Fe4B3 coating layer 75 Mn3Cu1Ho2Co3Zr 10 The Ni8 metal pieces 1 were stacked in a block-shaped mold with a length of 60 mm and a width of 40 mm to form a block. a The thickness h2 of the Gb metal piece 1 is set to h2 = 80 mm, and the thickness of the two adjacent layers of Fe a Between the Gb metal pieces 1, there is at least one layer of rare earth compound Re x M y B z The coating layer 2 was present. A specific example of the mold is shown in Figure 4. Reference numeral 3 denotes a lower mold for a block press, and reference numeral 4 denotes an upper mold for a block press.

[0032] (Step 3) Fe after lamination a The Gb metal piece 1 was pressed and subjected to a diffusion treatment in a vacuum to produce a block-shaped Nd-Fe-B magnetic material. The diffusion temperature was 1200°C and the diffusion time was 10 hours.

[0033] To measure the magnetic properties of the completed block-shaped Nd-Fe-B magnetic material, it was cut into a columnar sample with a diameter of 10 mm and a height of 10 mm and measured at a temperature of 20°C ± 3°C. The measurement results are shown in Table 1.

[0034] From the above measurement results, it is clear that the Nd-Fe-B magnetic material according to Example 3 has excellent magnetic properties, with a residual magnetic flux density Br of 8.23 kGs and a coercive force Hcj of 10.45 kOe.

[0035] Example 4 (Step 1) Fe in this example a G b is pure iron, and the mass percentages a and b are 100% and 0%, respectively. a A layer of rare earth compound Re is formed on the surface of the Gb metal piece 1. x M y B z Coating layer 2 was vapor-deposited. x M y Bz Nd 60 Pr 33 La1Tb 0.5 Ho 0.5 Mn 0.5 Ga 0.5 B4. Re is an aggregate of neodymium, praseodymium, lanthanum, terbium, and holmium, M is manganese and gallium, and B is boron. x, y, and z are mass percentages, and in Example 4, x is 95% of neodymium (60%), praseodymium (33%), lanthanum (1%), terbium (0.5%), and holmium (0.5%), y is 1% of manganese (0.5%), and potassium (0.5%), and z is 4% of boron. One layer of Fe a Gb The mass M1 of metal piece 1 and one layer of Fe a Rare earth compound Re on Gb metal piece 1 x M y B z The ratio of the mass of the coating layer 2 to the mass M2 was set to M2 / M1=40%. a The thickness h1 of the Gb metal piece 1 was set to h1=0.10 mm.

[0036] (Step 2) Rare earth compound Nd 60 Pr 33 La1Tb 0.5 Ho 0.5 Mn 0.5 Ga 0.5 Fe with B4 coating layer a The Gb metal piece 1 was wound in multiple layers around a core rod with a diameter of 56 mm and a height of 30 mm. a The thickness h2 of the Gb metal piece 1 was set to h2 = 2 mm, and then it was placed in a circular mold with an inner diameter of 60 mm and formed into a circular ring (cylindrical shape). a Between the Gb metal pieces 1, there is at least one layer of rare earth compound Re x M y B z The coating layer 2 was present. A specific example of the mold is shown in Figure 5. Reference numeral 7 denotes a core rod for the annular press, reference numeral 8 denotes an upper mold for the annular press, and reference numeral 9 denotes a lower mold for the annular press.

[0037] (Step 3) Fe after winding and lamination a The Gb metal piece 1 was pressed and subjected to a diffusion treatment in a vacuum to produce a ring-shaped Nd—Fe—B magnetic material. The diffusion temperature was 1150°C and the diffusion time was 2 hours.

[0038] To measure the magnetic properties of the completed ring-shaped Nd-Fe-B magnetic material, it was cut into a columnar sample with a diameter of 10 mm and a height of 2 mm and measured at a temperature of 20°C ± 3°C. The measurement results are shown in Table 1.

[0039] From the above measurement results, it can be seen that the annular Nd-Fe-B magnetic material according to Example 4 has excellent magnetic properties, with a residual magnetic flux density Br of 10.08 kGs and a coercive force Hcj of 9.58 kOe.

[0040] Example 5 (Step 1) Fe a G b Metal ingots are smelted and pressed to produce Fe a In Example 5, Fe a G b Fe 95 Ni2Nb 0.5 Mo 1.5 Co1. G is an aggregate of nickel, niobium, molybdenum, and cobalt. a and b are mass percentages, with a being 95% and b being 5%. The mass percentage of nickel was 2%, the mass percentage of niobium was 0.5%, the mass percentage of molybdenum was 1.5%, and the mass percentage of cobalt was 1%, and Fe was deposited by vacuum deposition. 95 Ni2Nb 0.5 Mo 1.5 Co1 metal piece has a layer of rare earth compound Re on its surface. x M y B z Coating layer 2 was vapor-deposited. x M y B z Nd 85 Al1Cu 0.5 Ga 0.5 Fe 10 Co 0。5 B 2.5Re is neodymium, M is aluminum, copper, gallium, iron, and cobalt, and B is boron. x, y, and z are mass percentages, where x is neodymium 85%, y is aluminum (1%), copper (0.5%), gallium (0.5%), iron (10%), and cobalt (0.5%), totaling 12.5%, and z is boron 2.5%. One layer of Fe a Gb The mass M1 of metal piece 1 and one layer of Fe a Rare earth compound Re on Gb metal piece 1 x M y B z The ratio of the mass of the coating layer 2 to the mass M2 was set to M2 / M1=55%. a The thickness h1 of the Gb metal piece 1 was set to h1=0.02 mm.

[0041] (Step 2) Rare earth compound Nd 85 Al1Cu 0.5 Ga 0.5 Fe 10 Co 0。5 B 2.5 Fe with coating layer a G b Fe 95 Ni2Nb 0.5 Mo 1.5 Co1 metal pieces were stacked in a block-shaped mold with a length of 10 mm and a width of 10 mm to form a block. a The thickness h2 of the Gb metal piece 1 is set to h2 = 0.04 mm, and the thickness of the two adjacent layers of Fe a Between the Gb metal pieces 1, there is at least one layer of rare earth compound Re x M y B z Coat layer 2 was present.

[0042] (Step 3) Fe after lamination a The Gb metal piece 1 was pressed and subjected to a diffusion treatment in a vacuum to produce a block-shaped Nd-Fe-B magnetic material. The diffusion temperature was 1000°C and the diffusion time was 0.5 hours.

[0043] To measure the magnetic properties of the completed block-shaped Nd-Fe-B magnetic material, it was cut into a columnar sample with a diameter of 10 mm and a height of 0.04 mm and measured at a temperature of 20°C ± 3°C. The measurement results are shown in Table 1.

[0044] From the above measurement results, it can be seen that the block-shaped Nd-Fe-B magnetic material according to Example 5 has excellent magnetic properties, with a residual magnetic flux density Br of 9.65 kGs and a coercive force Hcj of 11.57 kOe.

[0045] Table 1: Magnetic properties of magnetic materials according to Examples 1 to 5 JPEG2025119585000002.jpg72135

[0046] Example 6 The difference between Example 6 described below and Examples 1 to 5 described above is that the magnetic body of Example 6 is a laminate stacked to a predetermined thickness in a mold created in step 2, which is a stack of multiple laminates with different components. (Step 1) Fe a The Gb metal piece 1 is pure iron, and the mass percentages a and b are 100% and 0%, respectively. a A layer of rare earth compound Re is formed on the surface of the Gb metal piece 1. x M y B z Coating layer 2 was vapor-deposited. x M y B z Nd 60 Pr 34 Tb 0.5 Ho 0.5 Mn 0.5 Ga 0.5 B4. Re is a collection of neodymium, praseodymium, terbium, and holmium, M is manganese and gallium, and B is boron. x, y, and z are mass percentages, where x is the total of neodymium (60%), praseodymium (34%), terbium (0.5%), and holmium (0.5%), which is 95%, y is the total of manganese (0.5%) and potassium (0.5%), which is 1%, and z is boron 4%. One layer of Fe a Gb Mass M1 of metal piece 1 and one layer of Fe aRare earth compound Re on Gb metal piece 1 x M y B z The ratio of the mass of the coating layer 2 to the mass of the coating layer M2 was set to M2 / M1 = 40%. a The thickness h1 of the Gb metal piece 1 was set to h1=0.10 mm.

[0047] (Step 2) The rare earth compound Nd obtained in Step 1 60 Pr 34 Tb 0.5 Ho 0.5 Mn 0.5 Ga 0.5 Fe with B4 coating layer a A plurality of Gb metal pieces 1 were stacked in a block-shaped mold having a length and width of 30 mm, and formed into a block shape in the same manner as in Example 4. The thickness h2 was set to h2 = 5 mm, and the thickness of the two adjacent layers of Fe after stacking was a Between the Gb metal pieces 1, there is at least one layer of rare earth compound Re x M y B z Coat layer 2 was present.

[0048] (Step 3) Another Fe with a different composition from the above a This is a process for creating Gb metal pieces 1, Fe a G b Fe 95 Ni2Nb 0.5 Mo 1.5 Co1, and G are nickel, niobium, molybdenum, and cobalt. a and b are mass percentages, with a being 95% and b being 5%. Fe was deposited using a vacuum deposition method. a A layer of rare earth compound Re is formed on the surface of the Gb metal piece 1. x M y B z Coating layer 2 was vapor-deposited. x M y B z Nd 85 Al1Cu 0.5 Ga 0.5 Fe 10 Co 0。5 B 2.5Re is neodymium, M is aluminum, copper, gallium, iron, and cobalt, and B is boron. x, y, and z are mass percentages, where x is neodymium 85%, y is aluminum (1%), copper (0.5%), gallium (0.5%), iron (10%), and cobalt (0.5%), totaling 12.5%, and z is boron 2.5%. One layer of Fe a Gb Mass M1 of metal piece 1 and one layer of Fe a Rare earth compound Re on Gb metal piece 1 x M y B z The ratio of the mass of the coating layer 2 to the mass of the coating layer M2 was set to M2 / M1 = 55%. a The thickness h1 of the Gb metal piece 1 was set to h1=0.02 mm.

[0049] (Step 4) The rare earth compound Nd obtained in Step 3 85 Al1Cu 0.5 Ga 0.5 Fe 10 Co 0。5 B 2.5 Fe with coating layer 95 Ni2Nb 0.5 Mo 1.5 Co1 metal pieces were further stacked on the laminate prepared in step 2 and formed into a block shape similar to step 2 above. The final total thickness h3 was h3 = 10 mm. After stacking, the two adjacent layers of Fe a Between the Gb metal pieces 1, there is at least one layer of rare earth compound Re x M y B z Coat layer 2 was present.

[0050] (Step 5) Fe consisting of two laminates with different components created in Steps 2 and 4 above a The Gb metal piece 1 was pressed and subjected to a diffusion treatment in a vacuum to produce a block-shaped Nd-Fe-B magnetic material. The diffusion temperature was 1050°C and the diffusion time was 5 hours.

[0051] To measure the magnetic properties of the completed block-shaped Nd-Fe-B magnetic material, it was cut into a columnar sample with a diameter of 10 mm and a height of 15 mm, and measurements were performed at a temperature of 20°C ± 3°C. The columnar sample was then cut into a diameter of 10 mm and a height of 5 mm, and divided into cut columnar sample 1, cut columnar sample 2, and cut columnar sample 3. All measurement results are shown in Table 2.

[0052] Table 2: Magnetic properties of the magnetic material according to Example 6 JPEG2025119585000003.jpg52135

[0053] The above measurement results show that the block-shaped Nd-Fe-B magnetic material produced in Example 6 has excellent magnetic properties, with a residual magnetic flux density Br of 9.80 kGs and a coercive force Hcj of 11.20 kOe.

[0054] Furthermore, the measurement results of Samples 1 to 3 after division reveal that the magnetic properties of the magnetic material vary in the thickness direction, and that the magnetic properties change in gradient. That is, according to the method of Example 6, it is possible to manufacture a magnetic material with a gradient distribution of magnetic properties, and to provide a magnetic material that ensures good anti-demagnetization properties even under special demagnetization environments.

[0055] The above-described embodiments are merely preferred embodiments of the present invention and are not intended to limit the present invention. All modifications and improvements made within the scope of the technical concept of the present invention fall within the scope of protection of the present invention. [Explanation of symbols]

[0056] 1 Fe a G b metal piece 2 Rare earth compound Re x M y B z Coat layer 3 Lower formwork for block press 4 Upper formwork for block press 5 Upper formwork for roof tile press 6 Lower formwork for roof tile press 7 Core rod for circular press 8. Upper formwork for circular press 9 Lower formwork for circular press 10 Upper formwork for cylindrical press 11 Cylindrical press lower formwork

Claims

1. A method for producing an Nd—Fe—B based magnetic material, comprising the steps of: (Step 1) Fe ａ G ｂ At least one surface of the metal piece is coated with a layer of rare earth compound Re. ｘ M ｙ B ｚ Covered with a coating layer, (Step 2) The rare earth compound Re ｘ M ｙ B ｚ The Fe coated with a coating layer ａ G ｂ The metal pieces are stacked in a mold to a predetermined thickness, and the two adjacent layers of Fe ａ G ｂ At least one layer of the rare earth compound Re is provided between the metal pieces. ｘ M ｙ B ｚ There is a coating layer, (Step 3) The Fe after lamination ａ G ｂ The metal piece is pressed and subjected to a diffusion treatment in a vacuum to obtain an Nd—Fe—B magnetic material. The Fe ａ G ｂ In the metal pieces, Fe represents iron, G represents one or more of aluminum, titanium, copper, zinc, manganese, cobalt, nickel, niobium, molybdenum, zirconium, and chromium, a and b represent mass percentages, and 75%≦a≦100%, 0%≦b≦25%, The rare earth compound Re ｘ M ｙ B ｚ In the coating layer, Re is at least one of neodymium, praseodymium, cerium, lanthanum, terbium, dysprosium, and holmium, M is at least one of iron, aluminum, titanium, copper, zinc, manganese, cobalt, and gallium, and B is boron; x, y, and z represent mass percentages, where 70%≦x≦95%, 2%≦z≦4%, and y=1−x−z; A method for producing an Nd-Fe-B based magnetic material.

2. One layer of the Fe ａ G ｂ Mass of metal piece M １ and one layer of the Fe ａ G ｂ The rare earth compound Re on the metal piece ｘ M ｙ B ｚ Mass of the coating layer M ２ The ratio of ２ / M １ ≦80%; 2. The method for producing an Nd--Fe--B based magnetic material according to claim 1.

3. One layer of the Fe ａ G ｂ Thickness of the metal piece h １ 0.02 mm≦h １ ≦0.50 mm, 2. The method for producing an Nd--Fe--B based magnetic material according to claim 1.

4. The Fe after lamination ａ G ｂ The thickness of the metal piece and the rare earth compound Re ｘ M ｙ B ｚ Coat layer thickness h ２ 0.04 mm≦h ２ ≦80 mm, 2. The method for producing an Nd--Fe--B based magnetic material according to claim 1.

5. The Fe ａ G ｂ A layer of the rare earth compound Re covering the surface of the metal piece ｘ M ｙ B ｚ The coating layer is formed by vacuum deposition, plasma spraying, or thermal spraying.

2. The method for producing an Nd--Fe--B based magnetic material according to claim 1.

6. The Fe ａ G ｂ Stacking metal pieces to form a block, tile, cylinder or ring shape; 2. The method for producing an Nd--Fe--B based magnetic material according to claim 1.

7. The diffusion temperature in step 3 is 1000 to 1200°C, and the diffusion time is 0.5 to 10 hours.

2. The method for producing an Nd--Fe--B based magnetic material according to claim 1.

8. The laminate laminated to a predetermined thickness in the mold created in step 2 is a laminate obtained by stacking a plurality of laminates having different components.

2. The method for producing an Nd--Fe--B based magnetic material according to claim 1.

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