Method for preparing anisotropy MnAlC single variant through uniaxial pressure constraint transformation

Abstract

The invention provides a method for preparing an anisotropy MnAlC magnetic single variant through uniaxial pressure constraint transformation and the MnAlC single variant prepared by the method. The method comprises the steps of carrying out smelting, rod casting and single crystal growth on MnAlC raw materials to form a MnAlC-epsilon phase single crystal; and annealing the MnAlC-epsilon phase single crystal for 3-10 min under uniaxial pressure of 250-350MPa and temperature of 580-680 degrees centigrade, thereby preparing a MnAlC-tau phase single variant. The MnAlC-tau phase single variant prepared by the method has saturation magnetization intensity exceeding 100emu / g and complete anisotropy, and an equivalent magnetocrystalline anisotropy field is greater than 4T. The method and the MnAlC single variant have the advantages that (1), bicrystals in alloy can be effectively eliminated, the single variant organization is realized, the material has anisotropy, and the relatively good permanent magnet performance is obtained; (2), the technology is simple, and bad influences of produced microdefects and precipitated equilibrium phases on the magnetic performance can be completely avoided.

Description

technical field [0001] The invention relates to a treatment method for obtaining anisotropic MnAlC-τ phase single variant by performing uniaxial pressure annealing (580-680° C., 250-350 MPa) on MnAlC-ε phase single crystal. Background technique [0002] Permanent magnets are widely used in motors, generators, computers, electronic devices, communications, automobiles and aerospace industries, and have penetrated into every aspect of people's daily life. [0003] With the rise of rare earth prices and the gradual reduction of non-renewable rare earth resources, it is of great significance to study new non-rare earth permanent magnet materials that can replace the current largest amount of rare earth permanent magnet materials. However, the comprehensive properties of the existing non-rare earth permanent magnet materials cannot meet the requirements of high saturation magnetization, high anisotropy field, and high Curie temperature at the same time, thus limiting their applic...

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Problems solved by technology

[0005] However, due to the particularity of the martensitic phase transformation and crystal structure of the MnAl alloy, the τ phase prepared by the above method has a twin structure, so only isotropic polymorphs can be obtained, and the permanent magnetic properties are low.

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