Thermal deformation rare earth permanent magnet alloy and preparation method thereof

Abstract

The invention belongs to the field of rare earth permanent magnet materials, and discloses a thermal deformation rare earth permanent magnet alloy and a preparation method thereof.The preparation method comprises the steps that rare earth permanent magnet rapid quenching powder is cold-pressed into a blank; and carrying out thermal deformation treatment on the blank to obtain the thermal deformation rare earth permanent magnet alloy. An existing thermal deformation rare earth permanent magnet alloy preparation process is optimized, the hot pressing link is omitted, the blank does not need the repeated process of heating, cooling and reheating, the problem of microscopic coarsening of an existing process in a hot pressing high-temperature environment is solved, microscopic grain refinement of a rare earth permanent magnet ring or a magnetic strip is facilitated, and in the aspect of a mold, the yield of the rare earth permanent magnet ring or the magnetic strip is improved. And a high-temperature mold required by hot pressing is saved, so that the manufacturing cost is further reduced.

Description

Technical Field

[0001] The present application belongs to the field of rare earth permanent magnet materials, and in particular relates to a thermally deformed rare earth permanent magnet alloy and a preparation method thereof. Background Art

[0002] Rare earth permanent magnet materials are permanent magnet materials based on intermetallic compounds formed by rare earth metal elements and transition metal elements. They are widely used in automobiles, air conditioners, wind power generation, national defense, aerospace and other fields. They are important functional materials that support social progress.

[0003] At present, the preparation methods of rare earth permanent magnet materials mainly include sintering method and hot deformation method. Compared with the sintering method, the hot deformation method has the advantages of low rare earth dosage, good corrosion resistance, and near-final forming. The existing preparation process of hot-deformed rare earth permanent magnet materials mainly includes: cold pressing-hot pressing-hot deformation. Its equipment requires cold pressing machine, hot pressing machine and hot extrusion equipment. The blank needs to be heated, cooled and reheated repeatedly. Rare earth permanent magnet materials are prone to micro-coarsening problems under hot pressing and high temperature environment.

[0004] Therefore, it is necessary to provide a new hot-deformed rare earth permanent magnet alloy and a preparation method thereof to simplify the hot-deformation process and avoid the micro-coarsening problem of rare earth permanent magnet materials. Summary of the invention

[0005] In order to overcome the defects of the above-mentioned prior art, the present application provides a thermally deformed rare earth permanent magnet alloy and a preparation method thereof.

[0006] To achieve the above object, the present application provides a method for preparing a hot-deformed rare earth permanent magnet alloy, comprising:

[0007] Cold pressing the rare earth permanent magnet quick-quenching powder into a blank;

[0008] The blank is subjected to thermal deformation treatment to obtain a thermally deformed rare earth permanent magnet alloy.

[0009] Furthermore, the cold pressing pressure is 10-30 MPa, and the holding time is 10-15S.

[0010] Furthermore, the density of the blank is 5-6g / cm 3 .

[0011] Further, the thermal deformation treatment includes:

[0012] The blank is heated to 750-850° C., kept at this temperature for 60-240 seconds, and then kept at a pressure of 20-40 MPa for 10-15 seconds.

[0013] Furthermore, after the hot deformation treatment, the obtained hot-deformed rare earth permanent magnet alloy is furnace cooled or air cooled or water cooled.

[0014] Furthermore, the density of the hot-deformed rare earth permanent magnet alloy obtained by hot deformation treatment is 7.5-7.6 g / cm 3 .

[0015] The present application also provides a thermally deformed rare earth permanent magnet alloy, which is prepared by the above method.

[0016] Technical effects and advantages of this application:

[0017] The present application optimizes the existing preparation process of hot-deformed rare earth permanent magnet alloys, eliminates the hot pressing step, and does not require the repeated process of heating, cooling, and reheating of the blank, thus avoiding the micro-coarsening problem of the existing process in the high-temperature environment of hot pressing, which is beneficial to the micro-grain refinement of rare earth permanent magnet rings or magnetic strips; in terms of molds, it saves the high-temperature molds required for hot pressing, thereby further reducing the manufacturing cost.

[0018] Other features and advantages of the present application will be described in the following description, and partly become apparent from the description, or be understood by practicing the present application. The purpose and other advantages of the present application can be realized and obtained by the structures indicated in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a flow chart of a method for preparing a hot-deformed rare earth permanent magnet alloy of the present application. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0021] like Figure 1 As shown, the present application provides a method for preparing a hot-deformed rare earth permanent magnet alloy, comprising:

[0022] 1. Cold press the rare earth permanent magnet quick-quenching powder into a blank.

[0023] Put the rare earth permanent magnet quick quenching powder into the cold pressing mold, keep the pressure at 10-30MPa for 10-15S, and obtain a density of 5-6g / cm 3 of rough.

[0024] 2. Performing thermal deformation treatment on the blank to obtain a thermally deformed rare earth permanent magnet alloy.

[0025] The blank obtained in step 1 is placed in a hot deformation mold, heated to 750-850°C, kept warm for 60-240s, and then directly hot extruded at a pressure of 20-40MPa for 10-15s to obtain a ring-shaped or strip-shaped hot-deformed rare earth permanent magnet alloy.

[0026] 3. The obtained hot-deformed rare earth permanent magnet alloy is furnace cooled or air cooled or water cooled to obtain the final product.

[0027] The present application also provides a thermally deformed rare earth permanent magnet alloy, which is prepared by the above method.

[0028] In order to better illustrate the present invention, the following examples and comparative examples are provided.

[0029] Example 1

[0030] The MQ hot-pressed and rapidly quenched powder was placed in a cold-pressing mold and maintained at a pressure of 10 MPa for 10 seconds to obtain a density of 5 g / cm 3 of rough.

[0031] The obtained blank was placed in a hot deformation mold, heated to 750°C, kept warm for 60 seconds, and then directly hot extruded at a pressure of 20 MPa for 10 seconds to obtain a ring or strip with a density of 7.5 g / cm 3 Hot deformed rare earth permanent magnet alloy.

[0032] The obtained hot-deformed rare earth permanent magnet alloy is subjected to furnace cooling or air cooling or water cooling to obtain a final product.

[0033] After testing, the magnetic properties of the hot-deformed rare earth permanent magnet alloy prepared in Example 1 are: residual magnetic induction intensity (Br) 13.17 kGs, intrinsic coercive force (H cj )14.28kOe, maximum magnetic energy product (BH max )40.92MGOe.

[0034] Example 2

[0035] The MQ hot-pressed and rapidly quenched powder was placed in a cold-pressing mold and maintained at a pressure of 20 MPa for 13 seconds to obtain a density of 5.5 g / cm 3 of rough.

[0036] The obtained blank was placed in a hot deformation mold, heated to 800°C, kept warm for 120 seconds, and then directly hot extruded at a pressure of 30 MPa for 13 seconds to obtain a ring or strip with a density of 7.56 g / cm 3 Hot deformed rare earth permanent magnet alloy.

[0037] The obtained hot-deformed rare earth permanent magnet alloy is subjected to furnace cooling or air cooling or water cooling to obtain a final product.

[0038] After testing, the magnetic properties of the hot-deformed rare earth permanent magnet alloy prepared in Example 2 are: residual magnetic induction intensity (Br) 13.16 kGs, intrinsic coercive force (H cj )14.24kOe, maximum magnetic energy product (BH max )40.93MGOe.

[0039] Example 3

[0040] The MQ hot-pressed and rapidly quenched powder was placed in a cold-pressing mold and maintained at a pressure of 30 MPa for 15 seconds to obtain a density of 6 g / cm 3 of rough.

[0041] The obtained blank was placed in a hot deformation mold, heated to 850°C, kept warm for 240 seconds, and then directly hot extruded at a pressure of 40 MPa for 15 seconds to obtain a ring or strip with a density of 7.6 g / cm 3 Hot deformed rare earth permanent magnet alloy.

[0042] The obtained hot-deformed rare earth permanent magnet alloy is subjected to furnace cooling or air cooling or water cooling to obtain a final product.

[0043] After testing, the magnetic properties of the hot-deformed rare earth permanent magnet alloy prepared in Example 2 are: residual magnetic induction intensity (Br) 13.18 kGs, intrinsic coercive force (H cj )14.22kOe, maximum magnetic energy product (BH max )40.96MGOe.

[0044] Comparative Example

[0045] The MQ hot-pressed and rapidly quenched powder was placed in a cold-pressing mold and maintained at a pressure of 10 MPa for 10 seconds to obtain a density of 5 g / cm 3 of rough.

[0046] The obtained blank was placed in a hot pressing mold, heated to 650°C, and then hot pressed at a pressure of 20 MPa for 10 seconds to obtain a density of 7.5 g / cm 3 isotropic magnet.

[0047] The isotropic magnet is placed in a hot deformation mold, heated to 750°C, kept warm for 60 seconds, and then hot extruded at a pressure of 20 MPa for 10 seconds to obtain a ring or strip with a density of 7.5 g / cm 3 Hot deformed rare earth permanent magnet alloy.

[0048] The obtained hot-deformed rare earth permanent magnet alloy is subjected to furnace cooling or air cooling or water cooling to obtain a final product.

[0049] After testing, the magnetic properties of the thermally deformed rare earth permanent magnet alloy prepared in the comparative example are: residual magnetic induction intensity (Br) 13.14 kGs, intrinsic coercive force (H cj )14.18kOe, maximum magnetic energy product (BH max )40.81MGOe.

[0050] In summary, the present application optimizes the existing preparation process of hot-deformed rare earth permanent magnet alloys, eliminates the hot pressing step, and does not require repeated processes of heating, cooling, and reheating of the blank, thereby avoiding the micro-coarsening problem of the existing process in the high-temperature environment of hot pressing, which is beneficial to the micro-grain refinement of rare earth permanent magnet rings or magnetic strips. In terms of molds, the high-temperature molds required for hot pressing are saved, thereby further reducing the manufacturing cost. The magnetic properties of the obtained hot-deformed rare earth permanent magnet alloy are not significantly different from those of the hot-deformed rare earth permanent magnet alloy that has undergone the hot pressing step, thereby meeting market demand.

[0051] Finally, it should be noted that the above is only a preferred embodiment of the present application and is not intended to limit the present application. Although the present application has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing a hot-deformed rare earth permanent magnet alloy, characterized in that: include: Cold pressing the rare earth permanent magnet quick-quenching powder into a blank; The blank is subjected to thermal deformation treatment to obtain a thermally deformed rare earth permanent magnet alloy.

2. The method for preparing a hot-deformed rare earth permanent magnet alloy according to claim 1, characterized in that: The cold pressing pressure is 10-30 MPa, and the holding time is 10-15S.

3. The method for preparing a hot-deformed rare earth permanent magnet alloy according to claim 1, characterized in that: The density of the blank is 5-6g / cm 3 .

4. The method for preparing a hot-deformed rare earth permanent magnet alloy according to claim 1, characterized in that: The thermal deformation treatment comprises: The blank is heated to 750-850° C., kept at this temperature for 60-240 seconds, and then kept at a pressure of 20-40 MPa for 10-15 seconds.

5. The method for preparing a hot-deformed rare earth permanent magnet alloy according to claim 1, characterized in that: After the thermal deformation treatment, the obtained thermally deformed rare earth permanent magnet alloy is furnace cooled or air cooled or water cooled.

6. The method for preparing a hot-deformed rare earth permanent magnet alloy according to claim 1, characterized in that: The density of the hot-deformed rare earth permanent magnet alloy obtained by hot deformation treatment is 7.5-7.6 g / cm 3 .

7. A hot-deformed rare earth permanent magnet alloy, characterized in that: The hot deformed rare earth permanent magnet alloy is prepared by the method according to any one of claims 1 to 6.

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