A method for preparing high-performance composite magnetic powder

Abstract

The present invention discloses a method for preparing high-performance composite magnetic powder, which belongs to the field of magnetic material technology. The preparation method comprises: firstly preparing Sm2Fe 17 The invention relates to a method for preparing a magnetic particle and nitriding it to obtain a samarium iron nitrogen particle magnet; and during the high-energy ball milling process of metal Sm and metal Co, a mixture of the samarium iron nitrogen particle magnet and gasoline is sprayed into a mixed powder of metal Sm and metal Co in a spray manner, so that Sm and Co react chemically to achieve the synthesis of a hard magnetic phase Sm-Co phase, simplifying the preparation process, eliminating the smelting process, and avoiding the volatilization of Sm; finally, the magnetic mixed powder is subjected to a primary and secondary laser fast sintering nitriding and tempering heat treatment in a nitrogen atmosphere to finally obtain a high-performance composite magnetic powder. The method of the present invention has a simple process, is easy to form, reduces costs, and is conducive to the application of high-performance magnets in more permanent magnet devices.

Description

Technical Field

[0001] The present invention relates to the technical field of magnetic materials, and in particular to a method for preparing high-performance composite magnetic powder. Background Art

[0002] As an important functional material, magnetic materials play an extremely important role in modern society. In particular, the production, development and application of permanent magnetic materials are one of the indicators of modern national economic development. The development of rare earth permanent magnet materials is represented by three generations of permanent magnets, namely Sm-Co series and Nd-Fe-B series. Among them, Nd-Fe-B series permanent magnets are named "King of Magnets" for their excellent permanent magnetic properties. However, in the application process, the shortcomings of Nd-Fe-B series rare earth permanent magnets are also obvious, such as: Curie temperature ( T c ) is relatively low (~312°C), exhibiting poor corrosion resistance and temperature stability. With the continuous advancement of science and technology, there is an urgent need for permanent magnet materials that can maintain high permanent magnetic properties even in extreme environments. Consequently, Sm-Co rare earth permanent magnets have regained attention due to their high Curie temperature, excellent corrosion resistance, and excellent temperature stability. Simultaneously, SmFeN permanent magnets have attracted considerable attention since their introduction for their superior magnetic properties and excellent temperature stability. As the only permanent magnet capable of surpassing NdFeB in performance, they have become a hot topic in rare earth permanent magnet research both domestically and internationally.

[0003] To this end, the present invention first adopts vacuum induction melting technology to prepare Sm2Fe 17 The invention discloses a method for preparing a composite magnetic powder of metal Sm and Co by preparing the composite magnetic particles and nitriding the particles to obtain a samarium iron nitrogen particle magnet; and during the high-energy ball milling process of metal Sm and metal Co, a mixture of the samarium iron nitrogen particle magnet and gasoline is sprayed into the mixed powder of metal Sm and metal Co in a spray manner, so that Sm and Co react chemically to achieve the synthesis of the hard magnetic phase Sm-Co phase, simplifying the preparation process, eliminating the smelting process, and avoiding the volatilization of Sm; finally, the magnetic mixed powder is subjected to the first and second stage laser fast sintering nitriding and tempering heat treatment in a nitrogen atmosphere to obtain a high-performance composite magnetic powder. Summary of the Invention

[0004] In view of the problems existing in the prior art, the present invention aims to provide a method for preparing high-performance composite magnetic powder.

[0005] The method for preparing the high-performance composite magnetic powder of the present invention comprises the following steps:

[0006] (1) Using vacuum induction melting technology to prepare Sm2Fe 17 The alloy ingot is crushed and sieved into Sm2Fe 17magnetic particles, and then Sm2Fe 17 The magnetic particles were subjected to nitriding and aging treatment in N2 gas protection at 450-850 °C for 1-5 h, and then rapidly cooled to obtain samarium iron nitrogen particle magnets.

[0007] (2) Metal Sm and metal Co with a particle size range of 100-500 mesh are uniformly mixed in a weight ratio of 1:3-4, and then subjected to high-energy ball milling in a nitrogen atmosphere. At the same time, the mixture of the SmFeN granular magnet and gasoline obtained in step (1) is sprayed into the mixed powder of the metal Sm and metal Co, and the ball milling and spraying are continued until the ball milling is completed to obtain a magnetic mixed powder; the mixture of the SmFeN granular magnet and gasoline accounts for 50-100% of the weight of the metal Sm and metal Co, wherein the SmFeN granular magnet accounts for 10-50% of the total weight of the mixture;

[0008] (3) The magnetic mixed powder obtained in step (2) is subjected to primary and secondary laser rapid sintering nitriding and tempering heat treatments in a nitrogen atmosphere to obtain high-performance composite magnetic powder.

[0009] Furthermore, the high-energy ball milling time in step (2) is 1 to 10 h.

[0010] Furthermore, the temperature of the first-stage laser fast sintering nitriding and tempering heat treatment in step (3) is 550~900℃, the heating rate is 100~150℃ / min, the holding time is 1~10min, and then the heat treatment is rapidly cooled to room temperature; the temperature of the second-stage laser fast sintering nitriding and tempering heat treatment is 250~550℃, the heating rate is 100~150℃ / min, the holding time is 1~5min, and then the heat treatment is rapidly cooled to room temperature.

[0011] Compared with the existing technology, the present invention has the following advantages and beneficial effects: the present invention first adopts vacuum induction melting technology to prepare Sm2Fe 17 The invention discloses a method for preparing a composite magnetic powder of metal Sm and Co by preparing the composite magnetic particles and nitriding the particles to obtain a samarium iron nitrogen particle magnet; and during the high-energy ball milling process of metal Sm and metal Co, a mixture of the samarium iron nitrogen particle magnet and gasoline is sprayed into the mixed powder of metal Sm and metal Co in a spray manner, so that Sm and Co react chemically to achieve the synthesis of the hard magnetic phase Sm-Co phase, simplifying the preparation process, eliminating the smelting process, and avoiding the volatilization of Sm; finally, the magnetic mixed powder is subjected to the first and second stage laser fast sintering nitriding and tempering heat treatment in a nitrogen atmosphere to obtain a high-performance composite magnetic powder. Implementation Method

[0012] The present invention will be further described in detail below with reference to the examples, but the present invention is not limited to the following examples.

[0013] Example 1

[0014] (1) Using vacuum induction melting technology to prepare Sm2Fe 17 The alloy ingot is crushed and sieved into Sm2Fe 17 magnetic particles, and then Sm2Fe 17 The magnetic particles were nitrided and aged in N2 atmosphere at 550 °C for 5 h, and then rapidly cooled to obtain SmFeN particle magnets.

[0015] (2) Metal Sm and metal Co with a particle size range of 100 mesh are uniformly mixed in a weight ratio of 1:3 and then subjected to high-energy ball milling in a nitrogen atmosphere for 2 hours. At the same time, the mixture of the samarium iron nitrogen granular magnet and gasoline obtained in step (1) is sprayed into the mixed powder of metal Sm and metal Co in a spraying manner. The mixture of the samarium iron nitrogen granular magnet and gasoline accounts for 50% of the weight of the metal Sm and metal Co, and the samarium iron nitrogen granular magnet accounts for 10% of the total weight of the mixture. The ball milling and spraying are continued until the ball milling is completed to obtain a magnetic mixed powder;

[0016] (3) The magnetic mixed powder obtained in step (2) is subjected to primary and secondary laser rapid sintering nitriding and tempering heat treatments in a nitrogen atmosphere. The temperature of the primary laser rapid sintering nitriding and tempering heat treatment is 600 °C, the heating rate is 100 °C / min, the holding time is 10 min, and then the powder is rapidly cooled to room temperature. The temperature of the secondary laser rapid sintering nitriding and tempering heat treatment is 550 °C, the heating rate is 150 °C / min, the holding time is 1 min, and then the powder is rapidly cooled to room temperature, thereby finally obtaining a high-performance composite magnetic powder.

[0017] The high-performance composite magnetic powder prepared by the present invention has a remanence of 1.09 T, a coercive force of 12.7 kOe, and a magnetic energy product of 14.5 MGOe according to magnetic property measurement.

[0018] Example 2

[0019] (1) Using vacuum induction melting technology to prepare Sm2Fe 17 The alloy ingot is crushed and sieved into Sm2Fe 17 magnetic particles, and then Sm2Fe 17 The magnetic particles were nitrided and aged in N2 atmosphere at 700 °C for 3 h, and then rapidly cooled to obtain SmFeN particle magnets.

[0020] (2) Metal Sm and metal Co with a particle size range of 300 mesh are mixed in a weight ratio of 1:3.5 and then subjected to high-energy ball milling in a nitrogen atmosphere for 6 hours. At the same time, the mixture of the samarium iron nitrogen granular magnet and gasoline obtained in step (1) is sprayed into the mixed powder of metal Sm and metal Co in a spraying manner. The mixture of the samarium iron nitrogen granular magnet and gasoline accounts for 75% of the weight of the metal Sm and metal Co, and the samarium iron nitrogen granular magnet accounts for 30% of the total weight of the mixture. The ball milling and spraying are continued until the ball milling is completed to obtain a magnetic mixed powder;

[0021] (3) The magnetic mixed powder obtained in step (2) is subjected to primary and secondary laser rapid sintering nitriding and tempering heat treatments in a nitrogen atmosphere. The temperature of the primary laser rapid sintering nitriding and tempering heat treatment is 750°C, the heating rate is 125°C / min, the holding time is 5 min, and then the powder is rapidly cooled to room temperature. The temperature of the secondary laser rapid sintering nitriding and tempering heat treatment is 400°C, the heating rate is 125°C / min, the holding time is 3 min, and then the powder is rapidly cooled to room temperature, thereby finally obtaining a high-performance composite magnetic powder.

[0022] The high-performance composite magnetic powder prepared by the present invention has a remanence of 1.15 T, a coercive force of 14.2 kOe, and a magnetic energy product of 16.5 MGOe according to magnetic property measurement.

[0023] Example 3

[0024] (1) Using vacuum induction melting technology to prepare Sm2Fe 17 The alloy ingot is crushed and sieved into Sm2Fe 17 magnetic particles, and then Sm2Fe 17 The magnetic particles were nitrided and aged in N2 gas protection at 800 ℃ for 1 h, and then rapidly cooled to obtain SmFeN particle magnets.

[0025] (2) Metal Sm and metal Co with a particle size range of 500 mesh are uniformly mixed in a weight ratio of 1:4 and then subjected to high-energy ball milling in a nitrogen atmosphere for 9 hours. At the same time, the mixture of the samarium iron nitrogen granular magnet and gasoline obtained in step (1) is sprayed into the mixed powder of metal Sm and metal Co in a spraying manner. The mixture of the samarium iron nitrogen granular magnet and gasoline accounts for 100% of the weight of the metal Sm and metal Co, and the samarium iron nitrogen granular magnet accounts for 50% of the total weight of the mixture. The ball milling and spraying are continued until the ball milling is completed to obtain a magnetic mixed powder;

[0026] (3) The magnetic mixed powder obtained in step (2) is subjected to primary and secondary laser rapid sintering nitriding and tempering heat treatments in a nitrogen atmosphere. The temperature of the primary laser rapid sintering nitriding and tempering heat treatment is 900 °C, the heating rate is 150 °C / min, the holding time is 2 min, and then the powder is rapidly cooled to room temperature. The temperature of the secondary laser rapid sintering nitriding and tempering heat treatment is 250 °C, the heating rate is 100 °C / min, the holding time is 5 min, and then the powder is rapidly cooled to room temperature, thereby finally obtaining a high-performance composite magnetic powder.

[0027] The high-performance composite magnetic powder prepared by the present invention has a remanence of 1.17 T, a coercive force of 15.8 kOe, and a magnetic energy product of 17.4 MGOe according to magnetic property measurement.

Claims

1. A method for preparing high-performance composite magnetic powder, characterized in that The steps include: (1) Using vacuum induction melting technology to prepare Sm2Fe 17 The alloy ingot is crushed and sieved into Sm2Fe 17 magnetic particles, and then Sm2Fe 17 The magnetic particles were subjected to nitriding and aging treatment in N2 gas protection at 450-850 °C for 1-5 h, and then rapidly cooled to obtain samarium iron nitrogen particle magnets. (2) Metal Sm and metal Co with a particle size range of 100-500 mesh are uniformly mixed in a weight ratio of 1:3-4, and then subjected to high-energy ball milling in a nitrogen atmosphere. At the same time, the mixture of the SmFeN granular magnet and gasoline obtained in step (1) is sprayed into the mixed powder of the metal Sm and metal Co, and the ball milling and spraying are performed while the ball milling is completed to obtain a magnetic mixed powder; the mixture of the SmFeN granular magnet and gasoline accounts for 50-100% of the weight of the metal Sm and metal Co, and the SmFeN granular magnet accounts for 10-50% of the total weight of the mixture; (3) The magnetic mixed powder obtained in step (2) is subjected to primary and secondary laser rapid sintering nitriding and tempering heat treatments in a nitrogen atmosphere to obtain high-performance composite magnetic powder.

2. The method for preparing a high-performance composite magnetic powder according to claim 1, characterized in that: The high-energy ball milling time in step (2) is 1 to 10 h.

3. The method for preparing a high-performance composite magnetic powder according to claim 1, characterized in that: The temperature of the first-stage laser fast sintering nitriding and tempering heat treatment and the second-stage laser fast sintering nitriding and tempering heat treatment in step (3) is 550~900℃, the heating rate is 100~150℃ / min, the holding time is 1~10 min, and then the heat treatment is rapidly cooled to room temperature; the temperature of the second-stage laser fast sintering nitriding and tempering heat treatment is 250~550℃, the heating rate is 100~150℃ / min, the holding time is 1~5 min, and then the heat treatment is rapidly cooled to room temperature.