Method and device for preparing magnetostrictive material

Abstract

The invention discloses a method and device for preparing magnetostrictive material, which belong to the technical field of materials. The method comprises the following steps: (1) smelting to prepare Tb-Dy-Fe master alloy or Tb-Fe master alloy; (2) putting the master alloy in a crucible in a heating furnace, applying a balanced magnetic field, and heating the master alloy to obtain semi-solid material in the presence of a magnetic field and inert gas for isothermal treatment; and (3) in the presence of inert gas, cooling to 900+ / -5DEG C; then cooling to normal temperature to obtain the Tb-Dy-Fe or Tb-Fe magnetostrictive material. The device comprises a strong magnet, a heating furnace, a crucible, a bracket and a cooling medium container, wherein the lower end of the bracket is fixed on the bottom plate of the heating furnace; the bottom plate of the cooling medium container is in slip connection with the outer wall of the bracket; the cooling medium container is positioned between the crucible and the bottom plate of the heating furnace; and the bottom surface of the cooling medium container is connected with a gas-driven lifting device. With the method disclosed by the invention, the orientation degree of TbFe2 or (Tb, Dy)Fe2 in the alloy in (111) direction can be obviously improved. The device is simple to operate.

Description

technical field [0001] The invention belongs to the technical field of materials, and in particular relates to a method and a device for preparing magnetostrictive materials. Background technique [0002] Tb-Fe and Tb-Dy-Fe magnetostrictive materials have the advantages of large strain, high energy density, wide frequency band, high energy conversion efficiency, fast response speed, and good reliability. They are ideal for realizing electro-magnetic-mechanical energy conversion. One of the materials, it has become the core material of precision drives, smart sensors, transducers and other devices, and has a wide range of applications in national defense and civilian fields. The composition phase of Tb-Fe and Tb-Dy-Fe magnetostrictive materials is the Laves phase with cubic structure, that is, AB 2 type intermetallic compound, the direction of its easy magnetization axis is the <111> direction; since the magnetostriction coefficient in this direction is the largest, th...

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Problems solved by technology

The composition phase of Tb-Fe and Tb-Dy-Fe magnetostrictive materials is the Laves phase with cubic structure, that is, AB 2 type intermetallic compound, the direction of its easy magnetization axis is the direction; since the magnetostriction coefficient in this direction is the largest, the preparation of materials oriented in the direction has always been the goal pursued by material workers; so far , people have tried a variety of methods to prepare such materials; such as casting method, vertical floating zone melting method, Bridgman improved method, pulling method, ultra-high temperature gradient solidification method, powder metallurgy method and magnetic field heat treatment, etc.; However, since the easy growth direction of the Laves phase is the direction, it is difficult to obtain crystals oriented completely along the direction of the easy magnetization axis under ordinary solidification conditions; powder metallurgy can obtain polycrystals with a slightly dominant orientation material, but because the material has more porosity and holes, the magnetostriction coefficient decays quickly after being used under pressure for a period of time; vertical floating zone melting method, Bridgman improved method, pulling method, super high Directional solidification methods such as the temperature gradient solidification method are very effective in improving the orientation of the alloy, but the rare earth components are easily volatile during the smelting process, resulting in large fluctuations in composition and performance, high brittleness of the finished product, and complex equipment and processes

The magnetic field heat treatment process is simple, but this method cannot fundamentally change the orientation degree of the original polycrystalline material, so the improvement of the magnetostrictive properties of the material is limited

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