Preparation method of high-performance rare earth giant magnetostrictive material

Abstract

The invention provides a preparation method of a high-performance rare earth giant magnetostrictive material, and relates to the technical field of magnetic functional materials, and the preparation method comprises the following steps: step S1, proportioning according to the proportion of TbxDy1-x (Fe1-yMy) z, preparing a master alloy rod from the raw materials through vacuum induction melting, and then preparing a rare earth giant magnetostrictive material with 1t by adopting a directional solidification process; 110gt, 110gt; , lt; 112gt, 112gt; , lt; 113gt, 113gt; , lt; 111gt, 111gt; at least one type of oriented Tb-Dy-Fe-M alloy; s2, oriented annealing is conducted on the alloy subjected to directional solidification, and air cooling is conducted to the room temperature after annealing; and S3, the annealed alloy is subjected to heat treatment under the protective atmosphere and cooled to the room temperature. Through alloying design and preparation technology regulation and control, the resistivity of the material can be effectively improved, the eddy current loss is reduced, and the working efficiency of the material in an alternating magnetic field and the durability of the material in engineering application are improved. The method is easy to operate and suitable for industrial production.

Description

Technical Field

[0001] The invention relates to the technical field of magnetic functional materials, in particular to a method for preparing a high-performance rare earth giant magnetostrictive material. Background Art

[0002] Rare earth giant magnetostrictive material Tb-Dy-Fe - It is a functional material that realizes efficient conversion of electromagnetic energy and mechanical energy and information. It has the advantages of large magnetostrictive strain, high energy density, high conversion efficiency, and fast response speed. As a core material, it is used in devices such as low-frequency and high-power underwater acoustic transducers, high-precision micro-displacement precision brakes, vibrators, and smart sensors. However, the resistivity of Tb-Dy-Fe alloy is relatively low, only about 60×10 -8 Ω·m. Under the influence of an alternating magnetic field, the low resistivity causes large eddy currents within the alloy, which in turn accumulates a large amount of heat during application. This heat accumulation not only weakens the material's magnetostrictive properties but also significantly affects the transducer's operating efficiency, limiting its practical application in high-power applications.

[0003] There are two main technical solutions for improving the resistivity of giant magnetostrictive materials: one is to mix alloy powder with a binder through resin bonding; the other is to increase the resistivity of the material through alloying. Although the resin bonding method can effectively improve the resistivity of the material, its disadvantage is that it significantly reduces the magnetostrictive and mechanical properties of the material, and also affects the density of the alloy. The alloying method usually affects the composition, structure, and microstructure of the main phase of the alloy. Although it can improve the resistivity, it also damages the magnetostrictive properties of the alloy. Summary of the Invention

[0004] The present invention addresses the high brittleness and low resistivity of the rare earth giant magnetostrictive material Tb-Dy-Fe alloy, which results in significant eddy current losses when used in an alternating magnetic field. While cutting or powder bonding methods can partially alleviate this problem, they significantly impact the material's magnetostrictive and mechanical properties. Based on this, the present invention proposes a high-resistance and high-bending-resistance rare earth giant magnetostrictive material and a method for preparing it, effectively improving the material's resistivity and bending strength while minimizing the negative impact on its magnetostrictive properties.

[0005] The present invention is based on the principle of mixing enthalpy characteristics. Mixing enthalpy refers to the enthalpy change caused by the formation of new interactions when a substance or compound combines with other substances or compounds. In an alloy system, the mixing enthalpy reflects the enthalpy release or absorption of the system during the mixing process of alloy elements. When the mixing enthalpy is positive, it indicates that the mixing process is an endothermic reaction; when the mixing enthalpy is negative, it indicates that the mixing process is an exothermic reaction. The size of the mixing enthalpy not only reflects the strength of the binding force between heterogeneous atoms, but also has an important impact on the difficulty of the reaction. Therefore, the mixing enthalpy can be used as a key indicator to indirectly measure the bonding force between atoms. Based on the above principle, the present invention selects elements with negative mixing enthalpy with rare earth elements, and uses a directional solidification method to preferentially enrich these elements in the grain boundary area, while minimizing the impact on the main phase, effectively improving the resistivity and flexural strength of the material, thereby optimizing the performance of the giant magnetostrictive material.

[0006] The present invention provides a preparation method for improving the resistivity and flexural strength of giant magnetostrictive materials. This technical solution, based on the principle of mixing enthalpy calculation, selects specific elements (such as Al, Si, Bi, Sb, Mg, and Cu) that have negative mixing enthalpies with rare earth elements (such as Tb and Dy) and positive mixing enthalpies with iron (Fe) and mixes them with Tb, Dy, and Fe in specific proportions. These specific elements preferentially combine with the rare earth elements to form alloy phases with high resistivity or high flexural strength, effectively improving the material's resistivity and flexural strength. To ensure uniform distribution of the high-resistivity or high-flexural strength alloy phase within the material, the present invention utilizes a directional solidification process combined with an orientation-directed annealing method to distribute the generated high-resistance or high-flexural strength alloy phase in the grain boundaries of the alloy. This distribution creates an isolation barrier at the grain boundaries, effectively blocking electron conduction paths and crack propagation pathways, thereby significantly improving the material's resistivity and flexural strength. At the same time, by optimizing process parameters, the present invention minimizes the impact of high-resistivity alloys on magnetostrictive properties while simultaneously increasing resistivity, achieving a favorable balance between resistivity and magnetic properties. Through this technical solution, the present invention successfully addresses the technical challenges of achieving high resistivity, high bending strength, and excellent magnetic properties in giant magnetostrictive materials, providing a new approach and effective implementation path for the design and application of high-performance giant magnetostrictive materials.

[0007] Specifically, the technical solutions of the present invention are as follows:

[0008] A method for preparing a high-performance rare earth giant magnetostrictive material, comprising:

[0009] Step S1, according to Tb x Dy 1-x (Fe 1-y M y ) zThe raw materials are first melted by vacuum induction and then directional solidification process is used to prepare <110> 、 <112> 、 <113> 、 <111> At least one oriented Tb-Dy-Fe-M alloy; the element M tends to combine with the rare earth elements Tb or Dy to form a high-resistivity or high-toughness alloy phase. This high-resistivity or high-toughness alloy phase is then uniformly distributed within the alloy grain boundary phase through directional solidification and oriented annealing techniques, without affecting the composition, structure, and microstructure of the Laves main phase. This method effectively isolates adjacent Laves main phase grains, significantly improving the material's resistivity and mechanical properties while minimizing damage to the main phase's magnetostrictive properties, thereby maintaining its excellent magnetostrictive properties.

[0010] Step S2, performing orientation annealing on the directionally solidified alloy, and then air-cooling to room temperature after annealing;

[0011] Step S3, heat treating the annealed alloy under a protective atmosphere and cooling it to room temperature;

[0012] Wherein x=0.25-0.35; y=0.025-0.15; z=1.85-1.95; M is at least one selected from Al, Si, Bi, Sb, Mg, and Cu. Preferably, x=0.27-0.30; y=0.05-0.12; and z=1.90-1.95.

[0013] Based on mixing enthalpy calculations, specific elements with negative mixing enthalpy with Tb and Dy and positive mixing enthalpy with Fe are added to the Tb-Dy-Fe alloy, and the ingredients are prepared according to the above ratio. The added elements tend to combine with the rare earth elements to form high-resistivity or high-bending phases. Through directional solidification and orientation annealing, the high-resistivity or high-bending phases are evenly distributed in the grain boundary phase, thereby effectively isolating the main phase grains, reducing the circulation range of eddy currents, significantly reducing eddy current losses, and improving mechanical properties. At the same time, because the added elements do not enter the main phase, they have little impact on the overall magnetostrictive properties of the alloy, ensuring the excellent performance of the material.

[0014] Furthermore, in step S1, the directional solidification process is a temperature gradient of 50-500K / cm and a speed of 1-6mm / min. In step S1, by adjusting the temperature gradient and pulling speed of directional solidification and orientation annealing, oriented polycrystalline alloys with different preferred orientations, columnar crystal widths, grain boundary phase thicknesses and uniform structures are obtained. The prepared giant magnetostrictive material Tb-Dy-Fe-M alloy preferably has <110> Axial preferred orientation, columnar grain width of 40-120µm, and grain boundary phase thickness of 1-10µm. Alloys with different preferred orientations, different grain boundary phase compositions and thicknesses, and different main phase columnar grain widths can achieve different combinations of magnetostrictive properties, mechanical properties, and resistivity.

[0015] Furthermore, in step S2, the annealing process is as follows: annealing temperature 900-1100°C, hot zone width 2-10 mm, temperature gradient 10-200 K / cm and pulling speed 0.2-2 mm / min.

[0016] Furthermore, in step S3, the heat treatment process is to place the alloy that has completed orientation annealing in a vacuum heat treatment furnace, fill it with argon to 0.05MPa after the vacuum degree reaches 0.005Pa, and start heating to 600-900℃ and keep it for 1-6h; preferably, keep it at 720-880℃ for 2-4 hours.

[0017] Furthermore, in step S3, the cooling method is furnace cooling, air cooling, or quenching to room temperature, preferably air cooling.

[0018] Furthermore, it also has:

[0019] Step S4, preparing a sample from the heat-treated alloy;

[0020] Step S5: testing the magnetostrictive properties, mechanical properties (bending strength), and resistivity of the sample.

[0021] The present invention also provides a high-performance rare earth giant magnetostrictive material, the magnetostrictive performance of which is greater than 1100×10 -6 (magnetic field 1500Oe, 5MPa prestress), bending strength greater than 70MPa, resistivity greater than 100×10 -8 Ω·m.

[0022] The beneficial effects brought about by the technical solution provided by the embodiment of the present invention include at least:

[0023] (1) The selection of alloying elements and alloy design based on the principle of mixing enthalpy can not only ensure that the composition and crystal structure of the main phase of the alloy are not affected, thereby ensuring that the magnetic properties are not damaged, but also effectively improve the resistivity of the alloy, thereby reducing eddy current losses;

[0024] (2) Through directional solidification and orientation annealing technology, the width of the main phase of the crystalline structure, the width of the high-resistance and high-bending grain boundary phase, and the uniformity of the structure are effectively controlled to achieve an optimized combination of magnetostriction, resistivity, and mechanical properties. The comprehensive performance is better than that of materials prepared by slitting glue or powder bonding process.

[0025] (3) The alloy properties can be regulated by a single element component while the existing smelting process is used. The operation is simple, the processing steps are few, and it is suitable for large-scale industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 The present invention shows schematic diagrams of eddy currents in cross-section and longitudinal sections of columnar crystal alloy rods.

[0028] Figure 2 is Tb prepared in Example 1 of the present invention 0.27 Dy 0.73 (Fe 0.88 Al 0.05 Cu 0.07 ) 1.95 Microstructure image of the alloy.

[0029] Figure 3 The Tb prepared in Example 1 of the present invention 0.27 Dy 0.73 Fe 1.95 Alloy and Tb 0.27 Dy 0.73 (Fe 0.88 Al 0.05 Cu 0.07 ) 1.95 Magnetostrictive performance curve of the alloy.

[0030] Figure 4 The Tb prepared in Example 1 of the present invention 0.27 Dy 0.73 Fe 1.95 Alloy and Tb 0.27 Dy 0.73 (Fe 0.88 Al 0.05 Cu 0.07 ) 1.95 “Three-point bending” force-displacement curve of the alloy. DETAILED DESCRIPTION

[0031] The technical solution of the present invention is described below in conjunction with the accompanying drawings.

[0032] In the embodiments of the present invention, words such as "exemplarily" and "for example" are used to indicate examples, illustrations, or explanations. Any embodiment or design described as an "exemplary" in the present invention should not be interpreted as being preferred or advantageous over other embodiments or designs. Rather, the use of the word "exemplary" is intended to present concepts in a concrete manner. Furthermore, in the embodiments of the present invention, "and / or" can mean both or either of the two.

[0033] In the embodiments of the present invention, "image" and "picture" may sometimes be used interchangeably. It should be noted that, when the distinction between them is not emphasized, the meanings they convey are the same. "of," "corresponding," and "corresponding" may sometimes be used interchangeably. It should be noted that, when the distinction between them is not emphasized, the meanings they convey are the same.

[0034] In the embodiments of the present invention, sometimes a subscript such as W1 may be mistakenly written as a non-subscript form such as W1. When the difference is not emphasized, the meanings to be expressed are the same.

[0035] In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0036] Example 1: High bending strength <110> Oriented Tb 0.27 Dy 0.73 (Fe 0.88 Al 0.05 Cu 0.07 ) 1.95 Alloy refining.

[0037] 1. Prepared by batching, vacuum smelting and directional solidification <110> Oriented Tb 0.27 Dy 0.73 (Fe 0.88 Al 0.05 Cu 0.07 ) 1.9 The alloy has directional solidification parameters of temperature gradient 350K / cm and pulling speed 4mm / min. The prepared rod size is 20mm in diameter and 100mm in length.

[0038] 2. Place the alloy rod that has completed directionally solidified into a vacuum orientation annealing device for treatment. Set the annealing temperature to 1020°C, the hot zone width to 5 mm, the temperature gradient to 100 K / cm, and the pulling speed to 0.5 mm / min. After evacuating to 0.01 Pa, fill with argon to 0.05 MPa to start tissue orientation heat treatment, and then air cool to room temperature.

[0039] 3. Place the alloy rod that has undergone orientation annealing in a vacuum heat treatment furnace. After evacuating to 0.01Pa, fill it with argon to 0.05MPa, then heat it to 880℃ and keep it for 3 hours, then air cool it to room temperature.

[0040] 4. Use a wire cutting machine to process the alloy rod into 2×2×40 mm long strip samples and cylindrical samples with a diameter of 12 mm and a length of 30 mm.

[0041] 5. Use three-point bending test to test the room temperature flexural strength of the sample, and use resistance strain gauge method to test the magnetostrictive performance of the sample.

[0042] Its room temperature flexural strength and magnetostrictive properties (magnetic field 1500Oe, 5MPa prestress) are comparable to those of Tb 0.27 Dy 0.73 Fe 1.95 The comparison is shown in Table 1.

[0043]

[0044] Example 2: High Resistivity <113> Oriented Tb 0.25 Dy 0.75 (Fe 0.95 Si 0.025 Bi 0.025 ) 1.94 Alloy refining.

[0045] 1. Prepared by batching, vacuum smelting and directional solidification <113> Oriented Tb 0.25 Dy 0.75 (Fe 0.95 Si 0.025 Bi 0.025 ) 1.94 The alloy has directional solidification parameters of temperature gradient 370K / cm and pulling speed 3.5mm / min. The prepared rod size is 20mm in diameter and 100mm in length.

[0046] 2. Place the alloy rod that has completed directionally solidified into a vacuum orientation annealing device for treatment. Set the annealing temperature to 1040°C, the hot zone width to 3mm, the temperature gradient to 120K / cm, and the pulling speed to 0.8mm / min. After evacuating to 0.01Pa, fill with argon to 0.05MPa to start tissue orientation heat treatment, and then air cool to room temperature.

[0047] 3. Place the alloy rod that has undergone orientation annealing in a vacuum heat treatment furnace. After evacuating to 0.01Pa, fill it with argon to 0.05MPa, then heat it to 860℃ and keep it for 4 hours. Then cool the furnace to room temperature.

[0048] 4. Use a wire cutting machine to process the alloy rod into 2×2×40 mm long strip samples and cylindrical samples with a diameter of 12 mm and a length of 30 mm.

[0049] 5. Use AT515 precision resistance meter to test the resistivity of the sample, and use resistance strain gauge method to test the magnetostrictive performance of the sample.

[0050] Its resistivity and magnetostrictive properties (magnetic field 1500Oe, 5MPa prestress) are similar to those of Tb 0.27 Dy 0.73 Fe 1.94 The comparison is shown in Table 2.

[0051]

[0052] Figure 1 Schematic diagram of eddy currents in the cross section and longitudinal section of the columnar crystal alloy rod of the present invention. In the microstructure morphology of the alloy cross section (left figure), the white area is the Tb-Dy-Fe-M main phase grain, and the gray network area is the high-resistivity grain boundary phase rich in M ​​element. The grain boundary phase is continuously distributed between the main phase grains, forming a three-dimensional network structure, which effectively isolates adjacent grains. The red circular arrows indicate the distribution characteristics of eddy currents that are confined to the interior of each grain under the action of the alternating magnetic field. The right figure is a schematic diagram of the eddy current distribution in the longitudinal section along the crystal orientation direction, which intuitively demonstrates the technical effect of the present invention. Under the action of the alternating magnetic field, due to the barrier effect of the high-resistivity grain boundary phase, the macroscopic eddy currents (red solid arrows) that could originally penetrate the entire material are effectively suppressed, and only scattered eddy currents (orange solid arrows) are formed inside the grains and attenuated eddy currents (yellow dotted arrows) that pass through the grain boundaries are formed. This microstructure design that regulates the eddy current path through the grain boundary phase confines the eddy current circuit to the space between the main phase grains, thereby significantly reducing the eddy current loss of the material and improving the energy conversion efficiency and working stability of the giant magnetostrictive material under high-frequency application conditions.

[0053] Example 3: High flexural strength <112> Oriented Tb 0.28 Dy 0.72 (Fe 0.90 Sb 0.02 Cu 0.08 ) 1.93 Alloy refining.

[0054] 1. Prepared by batching, vacuum smelting and directional solidification <112> Oriented Tb 0.28 Dy 0.72 (Fe 0.90 Sb 0.02 Cu 0.08 ) 1.93 The alloy has directional solidification parameters of temperature gradient 320K / cm and pulling speed 3.8mm / min. The prepared rod size is 20mm in diameter and 100mm in length.

[0055] 2. Place the alloy rod that has completed directionally solidified into a vacuum orientation annealing device for treatment. Set the annealing temperature to 1020°C, the hot zone width to 3.5mm, the temperature gradient to 100K / cm, and the pulling speed to 0.6mm / min. After evacuating to 0.01Pa, fill with argon to 0.05MPa to start tissue orientation heat treatment, and then air cool to room temperature.

[0056] 3. Place the alloy rod that has undergone orientation annealing in a vacuum heat treatment furnace. After evacuating to 0.01Pa, fill it with argon to 0.05MPa, then heat it to 860℃ and keep it for 3 hours. Then cool the furnace to room temperature.

[0057] 4. Use a wire cutting machine to process the alloy rod into 2×2×40 mm long strip samples and cylindrical samples with a diameter of 12 mm and a length of 30 mm.

[0058] 5. Use three-point bending test to test the room temperature flexural strength of the sample, and use resistance strain gauge method to test the magnetostrictive performance of the sample.

[0059] Its resistivity and magnetostrictive properties (magnetic field 1500Oe, 5MPa prestress) are similar to those of Tb 0.28 Dy 0.72 Fe 1.93 The comparison is shown in Table 3.

[0060]

[0061] Example 4: High resistance <111> Oriented Tb 0.25 Dy 0.75 (Fe 0.91 Al 0.04 Si 0.02 Mg 0.03 ) 1.94 Alloy refining.

[0062] 1. Prepared by batching, vacuum smelting and directional solidification <111> Oriented Tb 0.25 Dy 0.75 (Fe 0.91 Al 0.04 Si 0.02 Mg 0.03 ) 1.94 The alloy has directional solidification parameters of temperature gradient 300K / cm and pulling speed 4.2mm / min. The prepared rod size is 20mm in diameter and 100mm in length.

[0063] 2. Place the alloy rod that has completed directionally solidified into a vacuum orientation annealing device for treatment. Set the annealing temperature to 1040°C, the hot zone width to 3.0 mm, the temperature gradient to 110 K / cm, and the pulling speed to 0.5 mm / min. After evacuating to 0.01 Pa, fill with argon to 0.05 MPa to start tissue orientation heat treatment, and then air cool to room temperature.

[0064] 3. Place the alloy rod that has undergone orientation annealing in a vacuum heat treatment furnace. After evacuating to 0.01Pa, fill it with argon to 0.05MPa, then heat it to 840℃ and keep it for 4 hours, then air cool it to room temperature.

[0065] 4. Use a wire cutting machine to process the alloy rod into 2×2×40 mm long strip samples and cylindrical samples with a diameter of 12 mm and a length of 30 mm.

[0066] 5. Use AT515 precision resistance meter to test the resistivity of the sample, and use resistance strain gauge method to test the magnetostrictive performance of the sample.

[0067] Its resistivity and magnetostrictive properties (magnetic field 1500Oe, 5MPa prestress) are similar to those of Tb 0.25 Dy 0.75 Fe 1.94 The comparison is shown in Table 4.

[0068]

[0069] Example 5: High bending resistance and high electrical resistance <110> Oriented Tb 0.27 Dy 0.73 (Fe 0.88 Al 0.03 Si 0.02 Cu 0.07 ) 1.95 Alloy refining.

[0070] 1. Prepared by batching, vacuum smelting and directional solidification <110> Oriented Tb 0.27 Dy 0.73 (Fe 0.88 Al 0.03 Si 0.02 Cu 0.07 ) 1.95 The alloy had directional solidification parameters of temperature gradient 380K / cm and pulling speed 4.0mm / min, and the prepared rod size was 20mm in diameter and 100mm in length.

[0071] 2. Place the alloy rod that has completed directionally solidified into a vacuum orientation annealing device for treatment. Set the annealing temperature to 1000°C, the hot zone width to 3.5mm, the temperature gradient to 150K / cm, and the pulling speed to 0.7mm / min. After evacuating to 0.01Pa, fill it with argon to 0.05MPa to start the tissue orientation heat treatment, and then air cool it to room temperature.

[0072] 3. Place the alloy rod that has undergone orientation annealing in a vacuum heat treatment furnace. After evacuating to 0.01Pa, fill it with argon to 0.05MPa, and then start heating to 800℃ and keep it for 4 hours. Then cool the furnace to room temperature.

[0073] 4. Use a wire cutting machine to process the alloy rod into 2×2×40 mm long strip samples and cylindrical samples with a diameter of 12 mm and a length of 30 mm.

[0074] 5. Use AT515 precision resistance meter to test the resistivity of the sample, use three-point bending to test the room temperature flexural strength of the sample, and use resistance strain gauge method to test the magnetostrictive performance of the sample.

[0075] Its resistivity and magnetostrictive properties (magnetic field 1500Oe, 5MPa prestress) are similar to those of Tb 0.27 Dy 0.73 Fe 1.95 The comparison is shown in Table 5.

[0076]

[0077] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A method for preparing a high-performance rare earth giant magnetostrictive material, characterized in that: include: Step S1, according to Tb x Dy 1-x (Fe 1-y M y ) z The raw materials are first melted by vacuum induction and then directional solidification process is used to prepare <110> 、 <112> 、 <113> 、 <111> at least one oriented Tb-Dy-Fe-M alloy; Step S2, performing orientation annealing on the directionally solidified alloy, and then air-cooling to room temperature after annealing; Step S3, heat treating the annealed alloy under a protective atmosphere and cooling it to room temperature; Wherein x=0.25-0.35; y=0.025~0.15; z=1.85-1.95; M is at least one selected from Al, Si, Bi, Sb, Mg, and Cu.

2. The method according to claim 1, characterized in that In step S1 , the directional solidification process is a temperature gradient of 50-500 K / cm and a speed of 1-6 mm / min.

3. The method according to claim 1, characterized in that In step S2, the annealing process is as follows: annealing temperature 900-1100°C, hot zone width 2-10 mm, temperature gradient 10-200 K / cm and pulling speed 0.2-2 mm / min.

4. The method according to claim 1, wherein In step S3, the heat treatment process is to place the alloy that has completed orientation annealing in a vacuum heat treatment furnace, fill it with argon to 0.05MPa after the vacuum degree reaches 0.005Pa, and start heating to 600-900℃ and keep it at this temperature for 1-6h.

5. The method according to claim 1, characterized in that In step S3, the cooling method is furnace cooling, air cooling, or quenching to room temperature.

6. The method according to claim 1, characterized in that Also features: Step S4, preparing a sample from the heat-treated alloy; Step S5: testing the magnetostrictive properties, mechanical properties (bending strength), and resistivity of the sample.

7. A high-performance rare earth giant magnetostrictive material prepared according to the method of any one of claims 1 to 6, characterized in that: Magnetostrictive performance is greater than 1100×10 -6 , flexural strength greater than 70MPa, resistivity greater than 100×10 -8 Ω·m.

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