Rare earth magnetostriction material and preparation method thereof

Abstract

The invention provides a preparation method of a rare earth magnetostriction material. The method comprises three processes of smelting, directional solidification and heat treatment. The directional solidification process comprises the following steps that 1, a magnetostriction alloy smelted solution obtained in a smelting crucible is poured into a quartz tube of a heat insulation device; 2, a pull-down process is started, and the quartz tube arranged on a base of a pull-down rod perpendicularly moves downwards along with the pull-down rod, wherein the downward moving process has three time periods, and different pull-down progresses are set in the different time periods; 3, in the downward moving process of the quartz tube, the alloy smelted solution in the quartz tube is gradually solidified, the pull-down process is finished after the quartz tube is completely moved out of the heat insulation device, and finally the alloy smelted solution forms a rare earth magnetostriction bar of a certain structure. In addition, the invention further provides the rare earth magnetostriction bar prepared through the method. The rare earth magnetostriction bar is good in crystallization property; meanwhile, the fluctuation range of magnetostriction coefficient of materials on upper, middle and lower different portions is small, and is 18ppm to the minimum.

Description

technical field [0001] The invention belongs to the field of magnetic materials, and relates to a preparation method for improving the performance consistency of rare earth magnetostrictive rods and a rare earth magnetostrictive material prepared by the method. technical background: [0002] Rare earth giant magnetostrictive material (TbDyFe 2 ) has the advantages of large magnetostriction coefficient, fast response speed, high energy density, etc., and has broad application prospects in many fields such as automobile industry, chemical industry, machinery and military affairs, and has been paid more and more attention by people. The directional solidification preparation technology of rare earth magnetostrictive materials mainly includes three methods: Czochralski method (Czochralski), Float Zone (FZ) method and Bridgman method (Bridgman) method. The Cukralski method is a directional solidification process using seed crystals. The crystal orientation of the prepared materi...

AI Technical Summary

Problems solved by technology

[0007] In the pull-down process of directional solidification, as the solidification process proceeds, the temperature gradient of the solidification interface will change, which will affect the solidification process of the alloy, resulting in uneven microstructure of the magnetostrictive rod, which will cause a large change in the material properties. fluctuations

Judging from the public technical information, there is no better solution to this problem

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