Method for preparing high-performance high-temperature-resisting nanometer composite permanent magnet

Abstract

The invention discloses a method for preparing a high-performance high-temperature-resisting nanometer composite permanent magnet, relating to preparation techniques of permanent magnetic materials. The method mainly comprises the following steps of: (1) weighing each element raw material according to elements of NdFeB alloy, mixing the element raw materials, melting the mixed raw material in vacuum, and rapidly quenching to prepare thin belts; (2) preparing SmCo ally rapidly quenched belts through the step (1); (3) respectively carrying out high-energy ball milling on the NdFeB and the SmCo alloy rapidly quenched belt to prepare corresponding nanometer crystal alloy powder; (4) mixing the NdFeB and the SmCo nanometer crystal alloy powder according to certain proportion, adding a crystal boundary nanometer modifier to be uniformly distributed on the surfaces of the NdFeB and the SmCo powders to obtain composite powder with the uniformly mixed three; (5) pressing the composite powder to form moulded blanks; (6) carrying out discharge plasma sintering on the moulded blanks to prepare a nanometer composite magnet; and (7) carrying out thermal deformation on the nanometer composite magnet to improve the degree of orientation and obtain the high-performance high-temperature-resisting nanometer composite permanent magnet. The method has the advantages of simple process and easiness in operation, and is suitable for large-scale batch production.

Description

technical field [0001] The invention relates to the technical field of permanent magnet material preparation, in particular to a method for preparing a high-performance high-temperature-resistant nanocomposite permanent magnet. Background technique [0002] Neodymium iron boron (NdFeB) permanent magnet is a new generation of rare earth permanent magnet material with high magnetic performance and high cost performance, widely used in various pillar industries and high-tech industries such as computers, communication information, medical treatment, transportation, audio equipment, office automation and home appliances. Technology industry; With the introduction and promotion of my country's energy conservation and emission reduction policy, the demand for high-performance and high-temperature-resistant magnets used in energy-saving and environmental protection fields such as electric vehicles and wind power continues to grow, and the magnetic energy product of NdFeB magnets has ...

AI Technical Summary

Problems solved by technology

[0002]NdFeB permanent magnet is a new generation of rare earth permanent magnet material with high magnetic performance and high cost performance, widely used in computer, communication information, medical treatment, transportation , audio equipment, office automation and home appliances and other pillar industries and high-tech industries; with the introduction and promotion of China's energy-saving and emission-reduction advocacy policy, the demand for high-performance, high-temperature-resistant magnets used in energy-saving and environmental protection fields such as electric vehicles and wind power With continuous growth, the magnetic energy product of NdFeB magnets has been greatly developed, and the maximum magnetic energy product has reached 474 kJ / m3 (59.5 MGOe). However, the development of its temperature stability has been relatively slow, which severely limits its further application

[0003]The temperature stability of NdFeB permanent magnet mainly depends on the Nd2Fe14B hard magnetic phase Intrinsic magnetic properties and microstructure of magnets; at present, the temperature stability of NdFeB magnets is mainly improved by alloying methods, such as the addition of heavy rare earth elements Dy, Tb, etc., which can effectively improve the Nd2 The anisotropic field of Fe14B realizes the temperature compensation of the magnetic moment, thereby increasing the coercive force, reducing the temperature coefficient, and improving its temperature stability; while the elements such as Co, Ni, Ga, and Si Addition can increase the Curie temperature of the magnet, and then improve the temperature stability; although the addition of alloy elements can effectively improve the temperature stability of the magnet, it is often accompanied by a decrease in the performance of the magnet. For this reason, the grain boundary diffusion technology has been greatly improved. The development of this new technology can effectively improve the temperature stability of the magnet under the premise of ensuring that the magnetic performance does not decrease or decreases very little; whether it is alloying or process optimization, the improvement of the temperature stability of the magnet is limited, and it is still not possible. To meet the ever-expanding application requirements; therefore, the development of new high-performance and high-temperature-resistant permanent magnets has become the key to further broaden its application space. Combining two kinds of permanent magnets with complementary performance characteristics together becomes a new high-performance and high-temperature-resistant composite permanent magnet. However, due to the lack of a good match between the selection of the composite system, the selection of the preparation process, and the control of the interface structure, the performance of the new composite magnet has not met the requirements.