A Ni-Fe-Mn-Ga magnetostrictive alloy and its preparation method

Abstract

This invention relates to the field of magnetostrictive materials, specifically to a Ni-Fe-Mn-Ga magnetostrictive alloy and its preparation method, comprising: an alloy with an atomic percentage of Ni. 57‑x Fe x Mn 20 Ga 23 ,in, x The content is: 1≤ x ≤14. This invention is based on the atomic ratio of Ni. 57 Mn 20 Ga 23 By replacing Ni with Fe to introduce point defects, Ni was obtained from the alloy composition. 57‑x Fe x Mn 20 Ga 23 (1≤ x ≤14) alloy system. When Fe replaces Ni, the strength and toughness of Ni-Mn-Ga alloy can be greatly improved; Fe, as a point defect, causes local lattice distortion in the austenitic matrix of the alloy, resulting in the formation of nano-martensite domains with low structural anisotropy and low reorientation energy barrier in the austenitic matrix, which can be generated in low saturation driving fields ( H S Reorientation under these conditions can also yield higher magnetostriction values. l This allows for the attainment of extremely high magnetostrictive sensitivity. l / H S ).

Description

Technical Field

[0001] This invention relates to the field of magnetostrictive materials, specifically to a Ni-Fe-Mn-Ga magnetostrictive alloy and its preparation method. Background Technology

[0002] Magnetostrictive materials are a class of key intelligent functional materials capable of sensing an applied magnetic field and generating mechanical deformation. Their core characteristic lies in their ability to efficiently achieve bidirectional conversion between electromagnetic and mechanical energy. With the rapid development of intelligent systems towards miniaturization and integration, higher performance requirements are being placed on magnetostrictive materials: not only do they need a larger magnetostriction coefficient (|... λ |) and a lower driving saturation magnetic field ( H S ), thereby achieving higher sensitivity (in terms of ratio | λ | / H S In addition to being quantifiable, it must also maintain stable performance over a wide temperature range and be insensitive to temperature changes.

[0003] In recent years, Fe-Pd ferromagnetic strained glass alloys with nanomartensite domains have emerged as strong candidates for highly sensitive magnetostriction due to their unique physical mechanism. Studies have shown that the nanomartensite domains in this alloy are extremely small and can be reoriented by a small magnetic field, resulting in a considerably large magnetostriction coefficient and high sensitivity. However, the high magnetostriction sensitivity of this system exists only at the freezing temperature of its strained glass transition. T Within a narrow temperature range near 0, as the temperature from T As the temperature drops to 0, the sensitivity decreases rapidly. This strong temperature dependence makes Fe-Pd ferromagnetic strain gauge glass alloys unsuitable for magnetic sensing and actuation applications in temperature-unstable environments. Furthermore, the high cost of Fe-Pd alloys limits their practical applications. Summary of the Invention

[0004] (a) Purpose of the invention The purpose of this invention is to provide a Ni-Fe-Mn-Ga magnetostrictive alloy with ultra-high magnetostrictive sensitivity over a wide temperature range and low cost, as well as its preparation method.

[0005] (II) Technical Solution To address the above problems, this invention provides a Ni-Fe-Mn-Ga magnetostrictive alloy, wherein the atomic percentage of the alloy is Ni. 57-x Fe x Mn 20 Ga 23 ,in, x The content is: 1 ≤ x ≤ 14.

[0006] In another aspect of the present invention, preferably, the... x The content is: 6 ≤ x ≤ 14, the alloy is a strained glassy alloy with nano-martensite domains.

[0007] In another aspect of the present invention, preferably, the alloy has a magnetostriction coefficient of -49.6ppm to -465ppm in the austenitic temperature range, a saturation magnetic field of 400 Oe to 4000 Oe, and a sensitivity of 0.025 to 0.775.

[0008] In another aspect of the present invention, preferably, the... x The content is: x = 14.

[0009] In another aspect of the present invention, preferably, the strained glassy alloy has a magnetic field strength of -73.5 ppm to -465 ppm over a wide temperature range of 300 K to 50 K, a saturation magnetic field strength of 400 Oe to 600 Oe, and a magnetostrictive sensitivity of 0.2 to 0.775. The magnetostriction value is -420 ppm to -465 ppm over a wide temperature range of 180 K to 50 K, the saturation magnetic field is about 600 Oe, and the magnetostriction sensitivity is about 0.7 to 0.775.

[0010] In another aspect of the present invention, preferably, a method for preparing the Ni-Fe-Mn-Ga magnetostrictive alloy as described above includes: Raw materials are weighed and mixed according to preset weighing rules to obtain an alloy mixture; The alloy mixture is placed in a melting device, evacuated to a first vacuum state, then filled with a first protective atmosphere, and melted under the first protective atmosphere to obtain a first alloy. The first alloy is polished, cleaned, and crushed to obtain the second alloy; The second alloy is placed in a tensile support body. After being evacuated to a second vacuum state, a second protective atmosphere is introduced. The tensile support body is heated and stretched under the second protective atmosphere. After cooling, a Ni-Fe-Mn-Ga magnetostrictive alloy is obtained.

[0011] In another aspect of the present invention, preferably, the preset weighing rule includes: the raw materials of Ni, Fe and Ga are proportioned according to a preset atomic percentage, the preset weighing amount of Mn raw material is A, the actual weighing amount of Mn raw material is B, and the preset weighing amount and the actual weighing amount of Mn raw material satisfy the following relationship: .

[0012] In another aspect of the present invention, preferably, the vacuum degree of the first vacuum is less than or equal to 3 × 10⁻⁶. -3 Pa; the first protective atmosphere includes argon gas, and the pressure of the first protective atmosphere is 0.03~0.05 MPa; The smelting apparatus is an electric arc melting furnace, the smelting temperature is 1400~1800 ℃, the smelting is performed 4~7 times, and the smelting time for each smelting is 1~2 min.

[0013] In another aspect of the present invention, preferably, the step of grinding, cleaning, and crushing the first alloy to obtain the second alloy includes: The oxide surface of the first alloy is polished to a preset thickness using an angle grinder; The first alloy after polishing was ultrasonically cleaned using acetone and anhydrous ethanol, respectively. The ultrasonic cleaning was performed at least twice, and each ultrasonic cleaning lasted for 6 to 10 minutes. The first alloy after cleaning is crushed into particles according to the preset particle size to obtain the second alloy.

[0014] In another aspect of the present invention, preferably, the tensile support is a corundum tube, and the vacuum degree of the second vacuum is less than or equal to 2 × 10⁻⁶. -3 Pa, the second protective atmosphere includes argon, the pressure of the second protective atmosphere is 0.03~0.05MPa; the heating temperature is 1600~1700 ℃, the stretching rate is 4~6 µm / s, and the heating and stretching time is 4~5 h.

[0015] (III) Beneficial Effects The above-described technical solution of the present invention has the following beneficial technical effects: This invention is based on atomic ratio Ni 57 Mn 20 Ga 23 By replacing Ni with Fe to introduce point defects, Ni was obtained from the alloy composition. 57-x Fe x Mn 20 Ga 23 (1 ≤ x ≤ 14) alloy system. When Fe replaces Ni, the strength and toughness of Ni-Mn-Ga alloy can be greatly improved; Fe, as a point defect, causes local lattice distortion in the austenitic matrix of the alloy, resulting in the formation of nano-martensite domains with low structural anisotropy and low reorientation energy barrier in the austenitic matrix, which can be generated in low saturation driving fields ( H S Reorientation under these conditions can also yield higher magnetostriction values ​​(| λ|), thus enabling the attainment of ultra-high magnetostrictive sensitivity (| λ | / H S ). Attached Figure Description

[0016] Figure 1 Ni of Example 1 43 Fe 14 Mn 20 Ga 23 Dynamic mechanical analysis (DMA) diagram of the alloy; Figure 2 Ni of Example 1 43 Fe 14 Mn 20 Ga 23 Magnetostrictive properties of the alloy at temperatures of 300 K, 230 K, 180 K, and 100 K; Figure 3 Ni of Example 1 43 Fe 14 Mn 20 Ga 23 Comparison of magnetostrictive sensitivity performance between the alloy and existing magnetostrictive materials; Figure 4 Ni in Example 2 51 Fe6Mn 20 Ga 23 Magnetostrictive properties of the alloy at temperatures of 300 K, 280 K, and 260 K; Figure 5 Ni in Example 3 56 Fe1Mn 20 Ga 23 Magnetostrictive properties of the alloy at temperatures of 300 K and 250 K; Figure 6 Ni in Example 4 53 Fe4Mn 20 Ga 23 Magnetostrictive properties of the alloy at temperatures of 350 K and 330 K, respectively; Figure 7 Ni in Example 5 47 Fe 10 Mn 20 Ga 23 Magnetostrictive properties of the alloy at temperatures of 300 K, 250 K, and 200 K. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0018] Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0019] In the description of this invention, it should be noted that the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0020] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0021] Example A Ni-Fe-Mn-Ga magnetostrictive alloy, wherein the atomic percentage of the alloy is Ni 57-x Fe x Mn 20 Ga 23 ,in, x The content is: 1 ≤ x ≤ 14. Where Fe element replaces Ni element in an equal atomic ratio, the substitution amount is... x The range of values ​​for is 1≤ x ≤ 14. Within the above composition range, point defects are introduced by substituting Ni with Fe. These point defects disrupt the strong long-range martensitic order in the original Ni-Mn-Ga alloy, causing localized lattice distortion and elastic property fluctuations in the austenite matrix, thus yielding Ni... 57-x Fe x Mn 20 Ga 23 (1 ≤ x ≤ 14) alloy system. Further, the aforementioned x The content is: 6 ≤ x ≤ 14, the alloy is a strained glassy alloy with nanoscale martensite domains. When Fe replaces Ni, the strength and toughness of the Ni-Mn-Ga alloy can be greatly improved. The introduction of Fe as a point defect causes local lattice distortion in the austenite matrix of the alloy, thereby forming a strained glassy state. The strained glassy magnetostrictive alloy of this embodiment is characterized by nanoscale martensite domains with low structural anisotropy and low reorientation energy barrier in the austenite matrix, which can be used in low saturation driving fields (H S Reorientation under these conditions can also yield higher magnetostriction values ​​(| λ |), thus enabling the attainment of ultra-high magnetostrictive sensitivity (| λ | / H S ).

[0022] Furthermore, in this embodiment, the... x The content is: 6 ≤ x ≤ 14, the strained glassy alloy exhibits a magnetostriction coefficient of -49.6 ppm to -465 ppm in the austenitic temperature range, a saturation magnetic field of 400 Oe to 600 Oe, and a sensitivity of 0.124 to 0.775. Within this composition range, as the Fe content increases, the size and distribution density of the nano-martensite domains are adjusted, further reducing the driving energy barrier required for domain reorientation and continuously improving the magnetostriction sensitivity.

[0023] Furthermore, in this embodiment, the... x The content is: x = 14, the strained glassy alloy has a magnetic field strength of -73.5 ppm to -465 ppm in a wide temperature range of 300 K to 50 K, a saturation magnetic field of 400 Oe to 600 Oe, and a magnetostrictive sensitivity of 0.2 to 0.775. The magnetostriction value is -420 ppm to -465 ppm over a wide temperature range of 180 K to 50 K, the saturation magnetic field is about 600 Oe, and the magnetostriction sensitivity is about 0.7 to 0.775, exhibiting excellent low-field high-response characteristics.

[0024] This embodiment also provides a method for preparing the Ni-Fe-Mn-Ga magnetostrictive alloy as described above, comprising: Raw materials are weighed and mixed according to a preset weighing rule to obtain an alloy mixture. The raw materials include bulk elemental raw materials of Ni, Fe, Mn, and Ga. This embodiment does not limit the specific form of the raw materials. Optionally, high-purity Ni, Fe, Mn, and Ga particles with a purity of not less than 99.9% can be used to minimize the adverse effects of impurities on the alloy performance. Based on the total mass of the target alloy and the atomic percentage of each element, combined with their corresponding atomic weights, the required mass of each element can be accurately calculated. The weighed raw materials are placed in a mixing container and thoroughly and uniformly mixed using a ball mill, mixer, or other suitable mixing equipment to ensure uniform distribution of each component during subsequent melting or sintering, laying the foundation for obtaining an alloy with consistent composition.

[0025] In this embodiment, the preset weighing rules include: the raw materials of Ni, Fe and Ga are proportioned according to a preset atomic percentage; the preset weighing amount of Mn raw material is A; the actual weighing amount of Mn raw material is B; and the preset weighing amount and the actual weighing amount of Mn raw material satisfy the following relationship: .

[0026] Due to the volatility of Mn raw materials during the electric arc melting process, the actual Mn content in the alloy may be lower than the preset value. In order to compensate for this volatility, in this embodiment, when the four bulk elemental raw materials Ni, Fe, Mn and Ga are proportioned according to atomic percentage, the actual amount of Mn bulk elemental raw material weighed is more than the preset amount.

[0027] The alloy mixture is placed in a melting apparatus, evacuated to a first vacuum state, and then filled with a first protective atmosphere. Melting is then carried out under the first protective atmosphere to obtain a first alloy. After the alloy mixture is placed in the melting apparatus, the interior of the apparatus is first evacuated to a first vacuum state to remove residual air, moisture, and other gases that may react with the alloy, thereby reducing the risk of oxidation or contamination of alloy elements during melting and ensuring alloy purity. Subsequently, while maintaining vacuum sealing, the first protective atmosphere is introduced into the melting apparatus to conduct the melting process in an inert gas environment, maintaining the stability of the alloy composition. In this embodiment, the vacuum degree of the first vacuum is less than or equal to 3 × 10⁻⁶. -3 The first protective atmosphere, consisting of argon, is used to effectively remove oxygen, water vapor, and other reactive gases from the furnace cavity, preventing oxidation or unnecessary chemical reactions of reactive elements such as Ni and Mn under high-temperature conditions, thereby improving the purity and compositional stability of the smelted alloy. The first protective atmosphere has a pressure of 0.03~0.05 MPa. The melting device is an electric arc melting furnace, the melting temperature is 1400~1800 ℃, the melting is performed 4~7 times, and each melting time is 1~2 minutes. The electric arc melting furnace is a semi-automatic sub-arc melting furnace; compared with other melting equipment, the semi-automatic sub-arc melting furnace is easier to operate and has the advantage of rapid heating, allowing the alloy to enter the molten state more quickly, thereby effectively shortening the melting time and improving overall production efficiency. The high temperature applied during the melting process and the repeated melting operations help the components to fully dissolve and diffuse, improving the uniformity of composition distribution. A uniform composition and dense structure are the key foundation for achieving excellent mechanical properties and good physical characteristics. In addition, multiple meltings can effectively reduce casting defects such as porosity and inclusions, further enhancing the density and mechanical properties of the alloy.

[0028] The first alloy is ground, cleaned, and crushed to obtain a second alloy; the specific details of the grinding and cleaning are not limited here. In this embodiment, grinding, cleaning, and crushing the first alloy to obtain the second alloy includes: The oxide surface of the first alloy is polished to a preset thickness using an angle grinder. The preset thickness is determined based on the degree of oxidation on the surface of the first alloy. Mechanical removal removes the oxide layer and adhering impurities formed on the alloy surface during melting and cooling, thereby exposing a uniformly composed and densely structured metal matrix. This step helps prevent surface oxides from entering the alloy interior during subsequent high-temperature treatment, which could affect microstructure evolution and performance stability. The preset thickness can be 0.1~0.5 mm, specifically 0.1 mm, 0.2 mm, 0.5 mm, etc.

[0029] The first alloy after grinding was ultrasonically cleaned using acetone and anhydrous ethanol, respectively. The ultrasonic cleaning was performed at least twice, with each cleaning session lasting 6-10 minutes. Ultrasonic cleaning further removed residual metal debris, oil, and other organic contaminants from the grinding process, improving the surface cleanliness of the alloy. The ultrasonic cleaning process could be repeated multiple times; it could begin with ultrasonic cleaning in acetone to remove oily contaminants, followed by ultrasonic cleaning in anhydrous ethanol to remove acetone residue and accelerate drying. The cleaned alloy surface was clean and free of significant contamination, which is beneficial for stability during subsequent crushing and high-temperature processing.

[0030] The first alloy, after cleaning, is crushed into particles according to a preset particle size to obtain the second alloy. After cleaning and natural drying or low-temperature drying, the first alloy is crushed into granular structures according to a preset particle size. The preset particle size is determined based on the subsequent loading method and heating uniformity requirements. For example, pliers are used to crush the cleaned first alloy into particles according to the preset particle size. The purpose of crushing into particles is to allow them to be encapsulated in a cylindrical corundum tube with an inner diameter of 8 mm. The maximum preset particle size can be 1 mm, 3 mm, 5 mm, etc. By controlling the particle size, the consistency of heating and stress on the alloy during subsequent heat treatment can be improved, reducing temperature gradients and stress concentration, and creating conditions for the formation of a uniformly distributed nano-martensite domain structure.

[0031] The second alloy is placed in a stretching support to prevent oxidation during heating. After evacuating to a second vacuum, a second protective atmosphere is introduced. The stretching support is then heated and stretched under this atmosphere, and after cooling, a Ni-Fe-Mn-Ga magnetostrictive alloy is obtained. A temperature gradient is created along the stretching direction, causing the molten alloy to flow in the opposite direction of heat flow. Upon cooling and solidification, this forms a directional solidified alloy with an oriented texture, which is beneficial for obtaining excellent magnetostrictive properties. In this embodiment, the stretching support is a corundum tube. Corundum tubes possess excellent high-temperature resistance, chemical stability, and mechanical strength, maintaining structural integrity under high temperature and tensile conditions, and providing reliable encapsulation and support for the second alloy throughout the process. The vacuum level of the second vacuum is less than or equal to 2 × 10⁻⁶. -3 The pressure of the second protective atmosphere is 0.03-0.05 MPa, further eliminating residual gases and moisture to reduce the risk of oxidation, contamination, or element volatilization during high-temperature processing. The second protective atmosphere comprises argon, with a pressure of 0.03-0.05 MPa, providing a stable inert environment for the heating and stretching processes. The heating temperature is 1600-1700 °C, a temperature range that allows the alloy to be in an austenite-dominant state, promoting the full activation of lattice defects and local elastic properties, creating conditions for the subsequent formation and stable distribution of nano-martensite domains. Simultaneously, the selection of the heating temperature takes into account both the alloy microstructure evolution requirements and the heat resistance limit of the corundum tube, ensuring a safe and reliable process. The stretching rate is 4-6 µm / s, allowing the alloy to slowly and stably withstand the applied load under high-temperature conditions. By controlling the stretching rate, microstructure inhomogeneity or structural damage caused by sudden stress changes can be avoided, and it is beneficial for the uniform transmission of stress within the alloy. The heating and stretching time is 4-5 h, allowing the alloy to fully complete the microstructure adjustment and stabilization process under the synergistic effect of high temperature and stress.

[0032] Example 1 The atomic percentage of magnetostrictive alloys is Ni. 43 Fe 14 Mn 20 Ga 23 ( x = 14); The preparation method includes: according to Ni 43 Fe 14 Mn 20 Ga 23 ( x The raw materials were weighed according to the atomic ratio of 14), and Ga, Fe, and Ni granules with a purity higher than 99.9% were selected as starting materials, with Mn added in excess of 3%. The above raw materials were uniformly mixed and then loaded into a semi-automatic argon arc melting furnace, and the vacuum was evacuated to below 3×10⁻⁶. -3The pressure was increased to Pa, then high-purity argon gas at 0.04 MPa was introduced as a protective atmosphere for arc melting, which was performed five times, each time for one minute, at a melting temperature of 1600 °C. Subsequently, the oxide layer on the surface of the resulting alloy ingot was mechanically ground using an angle grinder to a thickness of 0.2 mm; and then ultrasonically cleaned for 6 minutes each with acetone and anhydrous ethanol to remove surface contaminants. The cleaned sample was broken up with pliers and sealed in a cylindrical corundum crucible. The sealed corundum tube was placed in a directional solidification furnace, and a vacuum of 2 × 10⁻⁶ was applied again. -3 Below Pa, an argon protective atmosphere of 0.04 MPa was introduced, and the temperature was raised to 1650℃ to completely melt the sample. Subsequently, the corundum tube was stretched downwards at a constant rate of 5 μm / s to complete the directional solidification process. After the furnace body naturally cooled to room temperature, Ni with the target composition was obtained. 43 Fe 14 Mn 20 Ga 23 ( x = 14) directionally solidified magnetostrictive alloy.

[0033] The curves showing the changes in storage modulus and internal friction with temperature at different frequencies were obtained using a dynamic mechanical analyzer (DMA). Figure 1 Ni of Example 1 is shown 43 Fe 14 Mn 20 Ga 23 Dynamic mechanical analysis (DMA) diagram of the alloy, such as Figure 1 As shown, Ni 43 Fe 14 Mn 20 Ga 23 Evidence of strained glass transition; the fixture used in the test was a three-point bend fixture, the test amplitude was 5 μm, and the test frequency was selected as 0.2 / 0.4 / 1 / 4 / 10 / 20 Hz. Figure 1 As shown, this indicates that Ni 43 Fe 14 Mn 20 Ga 23 ( x = 14) The storage modulus of the alloy decreases with decreasing temperature, exhibiting a significant modulus softening valley around 200 K. The temperature corresponding to the minimum modulus of the modulus softening valley is ( T g ( ω )) and different frequencies ( ω It conforms to the Vogel-Fulcher relation specific to the glass transition. ω = ω 0exp [- E a / kB ( T g ( ω ) - T 0)], where T 0, E a , ω 0 and k B These are the ideal freezing temperature, activation energy, frequency factor, and Boltzmann constant for the strain glass transition. This indicates that Ni 43 Fe 14 Mn 20 Ga 23 The alloy underwent a typical strain glass transition, and its ideal freezing temperature... T 0 is 197.6 K. The main characteristic of the microstructure of strained glass is that nano-martensite domains are embedded in an austenitic matrix. In ferromagnetic strained glass, these nano-martensite domains have low energy barriers and are easily reoriented under a magnetic field, resulting in low-field driven large magnetostriction, thus potentially leading to ultra-high sensitivity magnetostrictive properties. Within the temperature range of 300 K to 50 K, Ni was subjected to various stable conditions at many different temperatures. 43 Fe 14 Mn 20 Ga 23 ( x = 14) The magnetostrictive properties of the directionally solidified magnetostrictive alloy samples were tested using a multifunctional magnetic measurement device. Figure 2 Ni of Example 1 is shown 43 Fe 14 Mn 20 Ga 23 Magnetostrictive properties of the alloy at temperatures of 300 K, 230 K, 180 K, and 100 K. At 300 K, the magnetostriction of the alloy is -73.5 ppm, corresponding to a saturation magnetic field of 400 Oe, and its corresponding sensitivity (| λ | / H S The magnetostriction of this alloy is 0.184 at 230 K, corresponding to a saturation magnetic field of 600 Oe. Its corresponding sensitivity (| λ | / H S The magnetostriction of this alloy is 0.518; at a temperature of 180 K, the magnetostriction is -465 ppm, the corresponding saturation magnetic field is 600 Oe, and its corresponding sensitivity (| λ | / H SThe value is 0.775; at a temperature of 100K, the austenitic magnetostriction of this alloy has a maximum value of -423.8 ppm, corresponding to a saturation magnetic field of 600 Oe, and its corresponding sensitivity (| λ | / H S The value is 0.706. Figure 3 Ni of Example 1 43 Fe 14 Mn 20 Ga 23 A comparison of the magnetostrictive sensitivity performance of the alloy and existing magnetostrictive materials, as shown in the figure. Figure 3 As shown, although commercial Terfenol-D exhibits a relatively large magnetostriction value, its large saturation driving field results in a low magnetostriction sensitivity over a wide temperature range. In contrast, Fe-Ga single crystals with nanoprecipitates exhibit higher magnetostriction sensitivity due to their lower driving saturation field, despite their smaller total magnetostriction value. Directional solidification of Fe 67.7 Pd 32.3 Ferromagnetic strain glass alloys exhibit extremely high sensitivity, but only within a narrow temperature window. In contrast, the Ni in this embodiment... 43 Fe 14 Mn 20 Ga 23 ( x = 14) The alloy samples exhibited higher magnetostrictive sensitivity (approximately 0.2–0.775) over a wide temperature range of 300 K to 50 K, particularly maintaining ultra-high sensitivity (approximately 0.7–0.775) between 180 K and 50 K, and demonstrated excellent temperature stability, significantly outperforming previously reported representative magnetostrictive materials. At the ideal strain glass freezing temperature... T Near 0, Ni 43 Fe 14 Mn 20 Ga 23 ( x = 14) The magnetostrictive sensitivity of the alloy sample reached a maximum of approximately 0.775. This indicates that Ni 43 Fe 14 Mn 20 Ga 23 ( x =14) alloys have great potential for applications of low-field driven actuators with high sensitivity over a wide temperature range.

[0034] Example 2 The atomic percentage of magnetostrictive alloys is Ni. 51 Fe6Mn 20 Ga 23 ( x= 6); The preparation method includes: according to Ni 51 Fe6Mn 20 Ga 23 ( x = 6) The raw materials were weighed according to the atomic ratio, and Ga, Fe and Ni block particles with a purity higher than 99.9% were selected as starting materials, with Mn added in excess of 2%; the above raw materials were mixed evenly and then loaded into a semi-automatic argon arc melting furnace, and the vacuum was drawn to below 3×10 -3 The pressure was increased to Pa, then high-purity argon gas at 0.03 MPa was introduced as a protective atmosphere for arc melting, which was performed 6 times, each time for 1.5 minutes, at a melting temperature of 1400 °C. Subsequently, the oxide layer on the surface of the resulting alloy ingot was mechanically ground using an angle grinder to a thickness of 0.3 mm; then, it was ultrasonically cleaned for 8 minutes each with acetone and anhydrous ethanol to remove surface contaminants. The cleaned sample was broken up with pliers and sealed in a cylindrical corundum crucible. The sealed corundum tube was placed in a directional solidification furnace, and a vacuum of 2 × 10⁻⁶ was applied again. -3 Below Pa, an argon protective atmosphere of 0.03 MPa was introduced, and the temperature was raised to 1600℃ to completely melt the sample. Subsequently, the corundum tube was stretched downwards at a constant rate of 4 μm / s to complete the directional solidification process. After the furnace body cooled naturally to room temperature, Ni with the target composition was obtained. 51 Fe6Mn 20 Ga 23 ( x = 6) directional solidification magnetostrictive alloy. Figure 4 Ni of Example 2 is shown 51 Fe6Mn 20 Ga 23 Magnetostrictive properties of the alloy at temperatures of 300 K, 280 K, and 260 K. At 300 K, the magnetostriction of the alloy is -49.6 ppm, corresponding to a saturation magnetic field of 400 Oe, and its corresponding sensitivity (| λ | / H S The magnetostriction of this alloy is 0.124 at 280 K, corresponding to a saturation magnetic field of 400 Oe, and its sensitivity is 0.124. λ | / H S The magnetostriction of this alloy is 0.157 at 260 K, corresponding to a saturation magnetic field of 400 Oe, and its sensitivity is 0.157. λ | / H S The value is 0.218.

[0035] Example 3 The atomic percentage of magnetostrictive alloys is Ni. 56 Fe1Mn 20 Ga 23 ( x = 1); The preparation method includes: according to Ni 56 Fe1Mn 20 Ga 23 ( x = 1) The raw materials were weighed according to the atomic ratio, and Ga, Fe and Ni block particles with a purity higher than 99.9% were selected as starting materials, with Mn added in excess of 4%; the above raw materials were mixed evenly and then loaded into a semi-automatic argon arc melting furnace, and the vacuum was drawn to below 3×10 -3 The pressure was increased to Pa, then high-purity argon gas at 0.05 MPa was introduced as a protective atmosphere for arc melting, which was performed 7 times, each time for 1 minute, at a melting temperature of 1800 °C. Subsequently, the oxide layer on the surface of the resulting alloy ingot was mechanically ground using an angle grinder to a thickness of 0.5 mm; then, it was ultrasonically cleaned for 10 minutes each with acetone and anhydrous ethanol to remove surface contaminants. The cleaned sample was broken up with pliers and sealed in a cylindrical corundum crucible. The sealed corundum tube was placed in a directional solidification furnace, and a vacuum of 2 × 10⁻⁶ was applied again. -3 Below Pa, an argon protective atmosphere of 0.05 MPa was introduced, and the temperature was raised to 1700℃ to completely melt the sample. Subsequently, the corundum tube was stretched downwards at a constant rate of 6 μm / s to complete the directional solidification process. After the furnace body naturally cooled to room temperature, Ni with the target composition was obtained. 56 Fe1Mn 20 Ga 23 ( x = 1) directional solidification magnetostrictive alloy. Figure 5 Ni of Example 3 is shown 57 Fe1Mn 20 Ga 23 Magnetostrictive properties of the alloy at temperatures of 300 K and 250 K, as shown in the figure. Figure 5 As shown, at a temperature of 300 K, the magnetostriction of this alloy is -100.3 ppm, corresponding to a saturation magnetic field of 4000 Oe, and its corresponding sensitivity (| λ | / H S The magnetostriction of this alloy is 0.025 at 250 K, corresponding to a saturation magnetic field of 4000 Oe, and its corresponding sensitivity is 0.025. λ | / H S The value is 0.039.

[0036] Example 4 The atomic percentage of magnetostrictive alloys is Ni. 53 Fe4Mn 20 Ga 23 ( x = 4); The preparation method includes: according to Ni 53 Fe4Mn 20 Ga 23 ( x = 4) The raw materials were weighed according to the atomic ratio, and Ga, Fe and Ni block particles with a purity higher than 99.9% were selected as starting materials, with Mn added in excess of 3%; the above raw materials were mixed evenly and then loaded into a semi-automatic argon arc melting furnace, and the vacuum was drawn to below 3×10 -3 The pressure was increased to Pa, then high-purity argon gas at 0.03 MPa was introduced as a protective atmosphere for arc melting, which was performed 6 times, each time for 1.5 minutes, at a melting temperature of 1400 °C. Subsequently, the oxide layer on the surface of the resulting alloy ingot was mechanically ground using an angle grinder to a thickness of 0.3 mm; then, it was ultrasonically cleaned for 8 minutes each with acetone and anhydrous ethanol to remove surface contaminants. The cleaned sample was broken up with pliers and sealed in a cylindrical corundum crucible. The sealed corundum tube was placed in a directional solidification furnace, and a vacuum of 2 × 10⁻⁶ was applied again. -3 Below Pa, an argon protective atmosphere of 0.03 MPa was introduced, and the temperature was raised to 1600℃ to completely melt the sample. Subsequently, the corundum tube was stretched downwards at a constant rate of 4 μm / s to complete the directional solidification process. After the furnace body cooled naturally to room temperature, Ni with the target composition was obtained. 53 Fe4Mn 20 Ga 23 ( x = 4) directional solidification magnetostrictive alloy. Figure 6 Ni of Example 4 is shown 53 Fe4Mn 20 Ga 23 Magnetostrictive properties of the alloy at temperatures of 350 K and 330 K, as shown in the figure. Figure 6 As shown, at a temperature of 350 K, the magnetostriction of this alloy is -46.4 ppm, corresponding to a saturation magnetic field of 800 Oe, and its corresponding sensitivity (| λ | / H S The magnetostriction of this alloy is 0.058 at 330 K, corresponding to a saturation magnetic field of 800 Oe, and its corresponding sensitivity is 0.058. λ | / H S The value is 0.072.

[0037] Example 5 The atomic percentage of magnetostrictive alloys is Ni. 47 Fe 10 Mn 20 Ga 23 ( x = 10); the preparation method includes: according to Ni 47 Fe 10 Mn 20 Ga 23 ( x The raw materials were weighed according to the atomic ratio of 10, and Ga, Fe and Ni granules with a purity higher than 99.9% were selected as starting materials, with Mn added in excess of 2%. The above raw materials were uniformly mixed and loaded into a semi-automatic argon arc melting furnace, and the vacuum was drawn to below 3×10. -3 The pressure was increased to Pa, then high-purity argon gas at 0.03 MPa was introduced as a protective atmosphere for arc melting, which was performed 6 times, each time for 1.5 minutes, at a melting temperature of 1400 °C. Subsequently, the oxide layer on the surface of the resulting alloy ingot was mechanically ground using an angle grinder to a thickness of 0.3 mm; then, it was ultrasonically cleaned for 8 minutes each with acetone and anhydrous ethanol to remove surface contaminants. The cleaned sample was broken up with pliers and sealed in a cylindrical corundum crucible. The sealed corundum tube was placed in a directional solidification furnace, and a vacuum of 2 × 10⁻⁶ was applied again. -3 Below Pa, an argon protective atmosphere of 0.03 MPa was introduced, and the temperature was raised to 1600℃ to completely melt the sample. Subsequently, the corundum tube was stretched downwards at a constant rate of 4 μm / s to complete the directional solidification process. After the furnace body cooled naturally to room temperature, Ni with the target composition was obtained. 47 Fe 10 Mn 20 Ga 23 ( x = 10) directional solidification magnetostrictive alloy. Figure 7 Ni of Example 5 is shown 47 Fe 10 Mn 20 Ga 23 Magnetostrictive properties of the alloy at temperatures of 300 K, 250 K, and 200 K are shown in the following figures. Figure 7 As shown, at a temperature of 300 K, the magnetostriction of this alloy is -58.1 ppm, corresponding to a saturation magnetic field of 400 Oe, and its corresponding sensitivity (| λ | / H S The magnetostriction of this alloy is 0.145 at 250 K, corresponding to a saturation magnetic field of 600 Oe, and its corresponding sensitivity is 0.145. λ | / H SThe magnetostriction of this alloy is 0.139 at 200 K, corresponding to a saturation magnetic field of 600 Oe, and its corresponding sensitivity is 0.139. λ | / H S The value is 0.238.

[0038] In summary, the magnetostrictive alloy of this embodiment exhibits ultra-high magnetostrictive sensitivity over a wide temperature range.

[0039] It should be understood that the specific embodiments described above are merely illustrative or explanatory of the principles of the invention and do not constitute a limitation thereof. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of the invention should be included within the protection scope of the invention. Furthermore, the appended claims are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

[0040] The present invention has been described above with reference to embodiments thereof. However, these embodiments are merely illustrative and not intended to limit the scope of the invention. The scope of the invention is defined by the appended claims and their equivalents. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of the invention, and all such substitutions and modifications should fall within the scope of the invention.

[0041] Although embodiments of the present invention have been described in detail, it should be understood that various changes, substitutions, and modifications can be made to the embodiments of the present invention without departing from the spirit and scope of the invention.

[0042] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A Ni-Fe-Mn-Ga magnetostrictive alloy, characterized in that, The atomic percentage of the alloy is Ni. 57- x Fe x Mn 20 Ga 23 ,in, x The content is: 1 ≤ x ≤ 14.

2. The Ni-Fe-Mn-Ga magnetostrictive alloy according to claim 1, characterized in that, The x The content is: 6≤ x ≤ 14, the alloy is a strained glassy alloy with nano-martensite domains.

3. The Ni-Fe-Mn-Ga magnetostrictive alloy according to claim 1, characterized in that, The alloy has a magnetostriction coefficient of -49.6 ppm to -465 ppm in the austenitic temperature range, a saturation magnetic field of 400 Oe to 4000 Oe, and a sensitivity of 0.025 to 0.

775.

4. The Ni-Fe-Mn-Ga magnetostrictive alloy according to claim 1, characterized in that, The x The content is: x =14.

5. The Ni-Fe-Mn-Ga magnetostrictive alloy according to claim 4, characterized in that, The alloy exhibits a magnetostrictive sensitivity of -73.5 ppm to -465 ppm over a wide temperature range of 300 K to 50 K, a saturation magnetic field of 400 Oe to 600 Oe, and a magnetostrictive sensitivity of 0.2 to 0.

775. The magnetostriction value is -420 ppm to -465 ppm over a wide temperature range of 180 K to 50 K, the saturation magnetic field is about 600 Oe, and the magnetostriction sensitivity is about 0.7 to 0.

775.

6. A method for preparing the Ni-Fe-Mn-Ga magnetostrictive alloy as described in any one of claims 1-5, characterized in that, include: Raw materials are weighed and mixed according to preset weighing rules to obtain an alloy mixture; The alloy mixture is placed in a melting device, evacuated to a first vacuum state, then filled with a first protective atmosphere, and melted under the first protective atmosphere to obtain a first alloy. The first alloy is polished, cleaned, and crushed to obtain the second alloy; The second alloy is placed in a tensile support body. After being evacuated to a second vacuum state, a second protective atmosphere is introduced. The tensile support body is heated and stretched under the second protective atmosphere. After cooling, a Ni-Fe-Mn-Ga magnetostrictive alloy is obtained.

7. The preparation method according to claim 6, characterized in that: The preset weighing rules include: the raw materials of Ni, Fe and Ga are proportioned according to a preset atomic percentage; the preset weighing amount of Mn raw material is A; the actual weighing amount of Mn raw material is B; and the preset weighing amount and the actual weighing amount of Mn raw material satisfy the following relationship: 。 8. The preparation method according to claim 6, characterized in that, The vacuum level of the first vacuum is less than or equal to 3 × 10⁻⁶. -3 Pa; the first protective atmosphere includes argon gas, and the pressure of the first protective atmosphere is 0.03~0.05 MPa; The smelting apparatus is an electric arc melting furnace, the smelting temperature is 1400~1800 ℃, the smelting is performed 4~7 times, and the smelting time for each smelting is 1~2 min.

9. The preparation method according to claim 6, characterized in that, The step of grinding, cleaning, and crushing the first alloy to obtain the second alloy includes: The oxide surface of the first alloy is polished to a preset thickness using an angle grinder; The first alloy after polishing was ultrasonically cleaned using acetone and anhydrous ethanol, respectively. The ultrasonic cleaning was performed at least twice, and each ultrasonic cleaning lasted for 6 to 10 minutes. The first alloy after cleaning is crushed into particles according to the preset particle size to obtain the second alloy.

10. The preparation method according to claim 6, characterized in that, The tensile support is a corundum tube, and the vacuum degree of the second vacuum is less than or equal to 2 × 10⁻⁶. -3 Pa, the second protective atmosphere includes argon, the pressure of the second protective atmosphere is 0.03~0.05 MPa; the heating temperature is 1600~1700 ℃, the stretching rate is 4~6 µm / s, and the heating and stretching time is 4~5 h.

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