A method for regulating energy state of amorphous alloy to improve soft magnetic performance

Abstract

The application discloses a method for regulating energy state of amorphous alloy to improve soft magnetic performance. The method adopts a base bearing type hot pressing process, lays an iron-based, cobalt-based or nickel-based soft magnetic amorphous strip on the surface of a porous base, carries out hot pressing treatment under the synchronous action of heating and pressing, and cools under the pressure maintaining condition, so that the energy state of the soft magnetic amorphous alloy is effectively regulated. The obtained soft magnetic amorphous alloy maintains a complete amorphous structure, the energy state is obviously optimized relative to the original strip, the saturation magnetic induction intensity is improved, and the coercive force is reduced. The application has the advantages of mild process, conventional equipment and easy large-scale production, and has important significance for performance regulation and engineering application of amorphous soft magnetic materials.

Description

Technical Field

[0001] This invention relates to a method for controlling the energy states of amorphous alloys to enhance their soft magnetic properties, and belongs to the field of amorphous alloy processing technology. Technical Background Amorphous alloys, also known as metallic glasses, are a class of metallic materials formed by freezing the disordered atomic arrangement of molten metal through rapid solidification technology. Their long-range disorder and short-range ordering structural characteristics endow them with high strength, high hardness, good corrosion resistance, and excellent soft magnetic properties, making them valuable in power electronic devices such as transformers and inductors.

[0002] From a thermodynamic perspective, amorphous alloys are metastable materials, with their internal atomic arrangement in a non-equilibrium frozen state. The internal energy and free volume content directly determine the energy state and structural stability. For soft magnetic amorphous alloys, excessively low energy states lead to the formation of numerous mid-range ordered structures, enhancing magnetocrystalline anisotropy, while excessively high energy states easily generate localized internal stresses, pinning magnetic domain walls and hindering the magnetization process, resulting in decreased permeability, increased coercivity, and other deterioration of soft magnetic properties. Therefore, regulating the energy state of soft magnetic amorphous alloys through external fields to achieve a state more favorable for soft magnetic properties has significant theoretical and practical value. These energy state changes can be characterized by parameters such as relaxation enthalpy, ultimately manifesting as changes in soft magnetic property indicators such as saturation magnetic induction and coercivity.

[0003] Currently, methods for controlling the energy states of amorphous alloys mainly include thermal cycling, high-pressure annealing, and uniaxial compression / stretching. While high-pressure annealing can freeze high-energy states by suppressing atomic diffusion under high pressure, its mechanism relies on the volume compression effect generated by GPa-level ultra-high pressure, requiring extremely sophisticated equipment and making large-area, continuous processing difficult. Thermal cycling utilizes extreme temperature differences to induce structural rejuvenation, but the process is energy-intensive, time-consuming, and complex to control. These methods generally suffer from harsh process conditions, high equipment costs, and poor sample uniformity, lacking a universal method that can effectively control energy states under mild conditions.

[0004] Therefore, developing a new method that can efficiently and uniformly control the energy state of amorphous alloy strips under relatively low temperature and low pressure conditions, and has the potential for large-scale production, has become a key technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing amorphous alloy energy state control technologies, such as stringent process conditions, high equipment requirements, long processing cycles, poor sample uniformity, and difficulty in large-scale production. This invention provides a method for controlling the energy state of amorphous alloys to improve their soft magnetic properties. This invention utilizes a hot-pressing and pressure-holding cooling process, taking advantage of the synergistic effect of the temperature and stress fields during hot pressing to effectively regulate the energy state of soft magnetic amorphous alloys. This method simplifies the process flow, reduces equipment and preparation costs, while simultaneously achieving effective control of the energy state of amorphous alloys and optimizing the soft magnetic properties of the material.

[0006] This invention first provides a method for controlling the energy states of amorphous alloys to improve their soft magnetic properties, which includes the following steps: 1) Cut the amorphous alloy strip to the preset size, grind, clean and dry the strip to remove the surface oxide layer and impurities; 2) Lay the amorphous alloy strip processed in step 1) flat on the surface of the porous substrate, put the porous substrate carrying the strip into the mold, and then place the mold in the heating device so that the upper and lower end faces of the mold are in contact with the pressure head of the press. 3) Set the heating program and pressurization parameters, and start the heating device and press simultaneously. Under the simultaneous action of heating and pressurization, the amorphous alloy strip in the mold is hot-pressed. 4) After the hot pressing treatment is completed, the sample is cooled to room temperature while maintaining pressure. The sample is then removed to obtain a soft magnetic amorphous alloy with energy state modulation.

[0007] Preferably, the amorphous alloy strip in step (1) is an iron-based, cobalt-based, or nickel-based soft magnetic amorphous alloy strip.

[0008] Preferably, the relaxation enthalpy of the amorphous alloy strip is less than 15 J / g, more preferably less than 10 J / g.

[0009] Typically, but not limited to, the amorphous alloy strip can be an iron-silicon-boron amorphous alloy strip, a cobalt-silicon-boron amorphous alloy strip, an iron-nickel-silicon-boron amorphous alloy strip, or it can also be an iron-based, cobalt-based, or nickel-based soft magnetic amorphous alloy strip doped with rare earth elements. For example, it can be Fe 78 Si9B 13 Co 73 Si9B 18 Fe 14 Ni 56 Si 10 B 18 Sm2 or Fe 40 Ni 40 B 16 Ce4, etc.

[0010] Preferably, the porous substrate in step (2) is copper foam, nickel foam, iron foam, titanium foam, aluminum foam, or porous stainless steel, wherein the porosity of the porous substrate is not less than 30%, and preferably, the porosity of the porous substrate is not less than 50%.

[0011] Preferably, the heating program and pressurization parameters in step (3) are: heating temperature 30-200℃, holding time 10-60min, heating rate 5-10℃ / min, and applied pressure 1.0-6.0MPa.

[0012] Preferably, the cooling method in step (4) is any one of furnace cooling, air cooling, wind cooling, oil cooling or water cooling.

[0013] The present invention also provides a soft magnetic amorphous alloy prepared by the above method. The soft magnetic amorphous alloy, after being controlled by the method of the present invention, maintains a completely amorphous structure and has a relaxation enthalpy of 20–35 J / g.

[0014] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention uses a porous substrate as a bearing interface to form a non-uniform contact state during hot pressing, thereby generating local stress concentration and non-uniform deformation inside the material, significantly changing the relaxation behavior of the amorphous alloy, and increasing the relaxation enthalpy from a low state to the energy range suitable for soft magnetic properties; (2) The present invention performs hot pressing under relatively low temperature and low pressure conditions, without the need for complex equipment and strict process conditions, and can achieve energy state control without causing amorphous crystallization, and has good macroscopic processing consistency; (3) The process flow of the present invention is simple and easy to operate, and the equipment used is all conventional industrial equipment, with low preparation cost and good potential for large-scale production. Attached Figure Description

[0015] Figure 1 The X-ray diffraction (XRD) patterns of Example 1, Comparative Example 1, and Comparative Example 2 of this invention are shown.

[0016] Figure 2 The differential scanning calorimetry (DSC) curves of Embodiment 1 and Comparative Examples 1 and 2 of the present invention are shown. Detailed Implementation

[0017] The technical solution of the present invention will be further described in detail below through specific embodiments, but the present invention is not limited to the following embodiments. The embodiments are merely examples of the content of this disclosure and do not limit the scope. The technical features of each embodiment in the present invention can be combined accordingly without mutual conflict.

[0018] Example 1: Hot-pressed Fe 78 Si9B 13 Preparation of soft magnetic amorphous alloy strips (1) Fe 78 Si9B 13 Iron-based amorphous strips were cut to a length of 1 cm, and the surface was polished with 1200-grit sandpaper to remove the oxide layer and contaminants. The polished strips were then ultrasonically cleaned in anhydrous ethanol for 10 minutes and allowed to air dry at room temperature for later use. (2) The amorphous alloy strip processed in step 1) is laid flat on the surface of a copper foam substrate with a thickness of 1 mm and a porosity of 70%. The copper foam substrate carrying the strip is placed into the mold, and then the mold is placed in the heating device so that the upper and lower end faces of the mold are in contact with the pressure head of the press. The mold consists of an upper mold, a middle mold and a lower bottom mold, wherein the middle mold forms a cylindrical cavity with an inner diameter of 12 mm; the heating device is a sleeve-type heating device, which has a hollow cavity that matches the shape of the mold and is used to cover the outer peripheral sidewall of the mold for heating, without covering the upper and lower end faces of the mold. (3) Set the heating program and pressurization parameters: heat from room temperature to 180℃ at a heating rate of 10℃ / min, hold for 10min, and apply a pressure of 4.0MPa. Simultaneously start the heating device and press, and perform hot pressing treatment on the amorphous alloy strip in the mold under the simultaneous action of heating and pressurization; (4) After the hot pressing treatment is completed, the furnace is cooled to room temperature under the pressure (4.0MPa). The mold is opened and the hot-pressed amorphous alloy strip is peeled off from the foamed copper substrate to obtain the soft magnetic amorphous alloy after energy state regulation.

[0019] Phase analysis of the hot-pressed sample (a soft magnetic amorphous alloy with modulated energy states) was performed using XRD, and the results are shown in the attached figure. Figure 1 As shown in the figure, the XRD pattern only shows broadened amorphous diffuse diffraction peaks, with no crystalline diffraction peaks appearing, indicating that the hot pressing treatment did not cause amorphous crystallization, and the sample maintained a completely amorphous structure; Thermal analysis of the hot-pressed sample was performed using DSC, and the DSC curves are shown in the attached figure. Figure 2 As shown. By integrating the exothermic peak before crystallization, the relaxation enthalpy of the sample was calculated to be 25.78 J / g.

[0020] The soft magnetic properties of the hot-pressed sample were tested using a vibrating sample magnetometer. The results showed that the saturation magnetic induction intensity of the sample was 1.67T and the coercivity was 2.5A / m.

[0021] Comparative Example 1: Hot-pressed Fe without a porous substrate support 78 Si9B 13 Preparation of soft magnetic amorphous alloy strips To compare the significant effect of the porous substrate of the present invention in hot pressing, a hot pressing of Fe without a porous substrate as a support was performed. 78 Si9B 13Using a soft magnetic amorphous alloy strip as Comparative Example 1, the specific steps are as follows: (1) Fe 78 Si9B 13 Iron-based amorphous strips were cut to a length of 1 cm, and the surface was polished with 1200-grit sandpaper to remove the oxide layer and contaminants. The polished strips were then ultrasonically cleaned in anhydrous ethanol for 10 minutes and allowed to air dry at room temperature for later use. (2) The amorphous alloy strip processed in step 1) is laid flat on the surface of the lower mold without a porous bearing base. The mold is then placed in the same heating device as in Example 1, so that the upper and lower end faces of the mold are in contact with the press head of the press. (3) Set the heating program and pressurization parameters: heat from room temperature to 180℃ at a heating rate of 10℃ / min, hold for 10min, and apply a pressure of 4.0MPa. Simultaneously start the heating device and press, and perform hot pressing treatment on the amorphous alloy strip in the mold under the simultaneous action of heating and pressurization; (4) After the hot pressing treatment is completed, the furnace is cooled to room temperature under the pressure (4.0MPa), the mold is opened, and the soft magnetic amorphous alloy after energy state regulation is obtained.

[0022] Phase analysis of the sample was performed using XRD, and the results are shown in the attached figure. Figure 1 As shown in the figure, the XRD pattern only shows broadened amorphous diffuse diffraction peaks, with no crystalline diffraction peaks appearing, indicating that the hot pressing treatment did not cause amorphous crystallization, and the sample maintained a completely amorphous structure; The samples were subjected to DSC analysis using the same test method as in Example 1, and the DSC curves are shown in the attached figure. Figure 2 As shown. The calculated relaxation enthalpy of the sample is 0.37 J / g.

[0023] The magnetic properties of the sample were tested using the same testing method as in Example 1. The results showed that the saturation magnetic induction intensity was 1.36T and the coercivity was 10.2A / m.

[0024] Comparative Example 2: Original Fe 78 Si9B 13 Amorphous alloy strip To compare the effect of hot pressing on the energy state regulation of amorphous alloys, raw Fe alloys without any hot pressing were used. 78 Si9B 13 The amorphous alloy strip, used as Comparative Example 2, is characterized as follows: (1) The original strips were subjected to XRD analysis using the same test method as in Example 1. The results are shown in the appendix. Figure 1 As shown, the original band also exhibits typical amorphous diffuse peaks, without crystalline diffraction peaks; (2) The original bands were subjected to DSC analysis using the same test method as in Example 1. The DSC curves are shown in the attached figure. Figure 2 As shown. The calculated relaxation enthalpy of the original band is 3.53 J / g.

[0025] (3) The original strip was tested for magnetic properties using the same test method as in Example 1. The results showed that the saturation magnetic induction intensity was 1.42T and the coercivity was 4.1A / m.

[0026] The comparison shows that the present invention successfully achieved Fe 78 Si9B 13 Energy state regulation of amorphous alloys. Compared to Comparative Example 1, under the same hot-pressing conditions, Example 1, using a porous substrate, showed an increase in the relaxation enthalpy from 0.37 J / g to 25.78 J / g, an increase in saturation magnetic induction of approximately 22.8%, and a decrease in coercivity of approximately 75.5%. This indicates that the porous substrate plays a crucial role in the energy state regulation and soft magnetic properties enhancement of amorphous alloys during hot pressing. Compared to Comparative Example 2, the relaxation enthalpy of the sample in Example 1 increased from a lower 3.53 J / g to a moderate 25.78 J / g, the saturation magnetic induction increased by approximately 17.6%, and the coercivity decreased by approximately 39.0%, significantly improving the soft magnetic properties of the iron-based amorphous alloy and demonstrating the inventiveness and effectiveness of the method of this invention.

[0027] Example 2: Hot-pressed Co 73 Si9B 18 Preparation of soft magnetic amorphous alloy strips (1) Co 73 Si9B 18 Cobalt-based amorphous strips were cut to 1cm in length, and their surface was polished with 1200-grit sandpaper to remove the oxide layer and contaminants. The polished strips were then ultrasonically cleaned in anhydrous ethanol for 10 minutes and allowed to air dry at room temperature for later use. (2) The amorphous alloy strip processed in step 1) is laid flat on the surface of a foamed iron substrate with a thickness of 1 mm and a porosity of 90%. The foamed iron substrate carrying the strip is placed into the mold, and then the mold is placed in the heating device so that the upper and lower end faces of the mold are in contact with the press head of the press. The mold consists of an upper mold, a middle mold and a lower bottom mold, wherein the middle mold forms a cylindrical cavity with an inner diameter of 12 mm; the heating device is a sleeve-type heating device, which has a hollow cavity that matches the shape of the mold, and is used to cover the outer peripheral sidewall of the mold for heating, without covering the upper and lower end faces of the mold; (3) Set the heating program and pressurization parameters: heat from room temperature to 30℃ at a heating rate of 5℃ / min, hold for 10min, and apply a pressure of 6.0MPa. Simultaneously start the heating device and press, and perform hot pressing treatment on the amorphous alloy strip in the mold under the simultaneous action of heating and pressurization; (4) After the hot pressing process is completed, the amorphous alloy strip is cooled to room temperature under pressure, the mold is opened, and the hot-pressed amorphous alloy strip is peeled off from the foamed iron substrate to obtain the soft magnetic amorphous alloy after energy state regulation.

[0028] Phase analysis of the hot-pressed sample was performed using XRD. The XRD pattern showed only broadened amorphous diffuse diffraction peaks, with no crystalline diffraction peaks, indicating that the hot-pressing treatment did not induce amorphous crystallization, and the sample maintained a completely amorphous structure. Thermal analysis of the hot-pressed sample was performed using DSC. The relaxation enthalpy of the sample was calculated to be 22.64 J / g by integrating the exothermic peak before crystallization.

[0029] The soft magnetic properties of the hot-pressed sample were tested using a vibrating sample magnetometer. The results showed that the saturation magnetic induction intensity of the sample was 0.91T and the coercivity was 3.4A / m.

[0030] Comparative Example 3: Original Co 73 Si9B 18 Amorphous alloy strip To compare the effect of hot pressing on the energy state regulation of amorphous alloys, raw Co alloys without any hot pressing were used. 73 Si9B 18 The amorphous alloy strip, used as Comparative Example 3, is characterized as follows: (1) The original band was subjected to XRD analysis using the same test method as in Example 2. The original band also showed typical amorphous diffuse peaks and no crystalline diffraction peaks. (2) The original strip was subjected to DSC analysis using the same test method as in Example 2, and the relaxation enthalpy of the original strip was calculated to be 1.32 J / g.

[0031] (3) The original strip was tested for magnetic properties using the same test method as in Example 2. The results showed that the saturation magnetic induction intensity was 0.76T and the coercivity was 5.6A / m.

[0032] The comparison shows that the present invention successfully achieved Co 73 Si9B 18 Energy state modulation of amorphous alloys. Compared with Comparative Example 3, the relaxation enthalpy of the sample in Example 2 increased from a lower 1.32 J / g to a moderate 22.64 J / g, the saturation magnetic induction increased by about 19.7%, and the coercivity decreased by about 39.3%, significantly improving the soft magnetic properties of the cobalt-based amorphous alloy, demonstrating the inventiveness and effectiveness of the method of the present invention.

[0033] Example 3: Hot-pressed Fe 14 Ni 56 Si 10 B 18 Preparation of Sm2 soft magnetic amorphous alloy strips (1) Fe 14 Ni 56 Si 10 B 18 Sm2 nickel-iron-based amorphous strips were cut to a length of 1cm, and the surface was polished with 1200-grit sandpaper to remove the oxide layer and contaminants. The polished strips were then ultrasonically cleaned in anhydrous ethanol for 10 minutes and allowed to air dry at room temperature for later use. (2) The amorphous alloy strip processed in step 1) is laid flat on the surface of a porous stainless steel substrate with a thickness of 1 mm and a porosity of 50%. The porous stainless steel substrate carrying the strip is placed into the mold, and then the mold is placed in the heating device so that the upper and lower end faces of the mold are in contact with the pressure head of the press. The mold consists of an upper mold, a middle mold and a lower bottom mold, wherein the middle mold forms a cylindrical cavity with an inner diameter of 12 mm; the heating device is a sleeve-type heating device, which has a hollow cavity that matches the shape of the mold and is used to cover the outer peripheral sidewall of the mold for heating, but does not cover the upper and lower end faces of the mold. (3) Set the heating program and pressurization parameters: heat from room temperature to 90℃ at a heating rate of 10℃ / min, hold for 20min, and apply a pressure of 4.0MPa. Simultaneously start the heating device and press, and perform hot pressing treatment on the amorphous alloy strip in the mold under the simultaneous action of heating and pressurization; (4) After the hot pressing treatment is completed, the furnace is cooled to room temperature while maintaining pressure. The mold is opened and the hot-pressed amorphous alloy strip is peeled off from the porous stainless steel substrate to obtain the energy-controlled soft magnetic amorphous alloy.

[0034] Phase analysis of the hot-pressed sample was performed using XRD. The XRD pattern showed only broadened amorphous diffuse diffraction peaks, with no crystalline diffraction peaks, indicating that the hot-pressing treatment did not induce amorphous crystallization, and the sample maintained a completely amorphous structure. Thermal analysis of the hot-pressed sample was performed using DSC. The relaxation enthalpy of the sample was calculated to be 23.58 J / g by integrating the exothermic peak before crystallization.

[0035] The soft magnetic properties of the hot-pressed sample were tested using a vibrating sample magnetometer. The results showed that the saturation magnetic induction intensity of the sample was 1.13T and the coercivity was 4.6A / m.

[0036] Comparative Example 4: Original Fe 14 Ni 56 Si 10 B 18 Sm2 amorphous alloy strip To compare the effect of hot pressing on the energy state regulation of amorphous alloys, raw Fe alloys without any hot pressing were used. 14 Ni 56 Si 10 B18 The Sm2 amorphous alloy strip, used as Comparative Example 4, is characterized as follows: (1) The original band was subjected to XRD analysis using the same test method as in Example 3. The original band also showed typical amorphous diffuse peaks and no crystalline diffraction peaks. (2) The original strip was subjected to DSC analysis using the same test method as in Example 3, and the relaxation enthalpy of the original strip was calculated to be 2.63 J / g.

[0037] (3) The original strip was tested for magnetic properties using the same test method as in Example 3. The results showed that the saturation magnetic induction intensity was 0.95T and the coercivity was 14.6A / m.

[0038] The comparison shows that the present invention successfully achieved Fe 14 Ni 56 Si 10 B 18 Energy state modulation of Sm2 amorphous alloy. Compared with Comparative Example 4, the relaxation enthalpy of the sample in Example 3 increased from a lower 2.63 J / g to a moderate 23.58 J / g, the saturation magnetic induction increased by about 18.9%, and the coercivity decreased by about 68.5%, significantly improving the soft magnetic properties of the nickel-iron-based amorphous alloy, demonstrating the inventiveness and effectiveness of the method of the present invention.

[0039] The above-described embodiments are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. Those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A method for controlling the energy states of an amorphous alloy to enhance its soft magnetic properties, characterized in that, Includes the following steps: 1) Cut the amorphous alloy strip to the preset size, grind, clean and dry the strip to remove the surface oxide layer and impurities; 2) Lay the amorphous alloy strip processed in step 1) flat on the surface of the porous substrate, put the porous substrate carrying the strip into the mold, and then place the mold in the heating device so that the upper and lower end faces of the mold are in contact with the pressure head of the press. 3) Set the heating program and pressurization parameters, and start the heating device and press simultaneously. Under the simultaneous action of heating and pressurization, the amorphous alloy strip in the mold is hot-pressed. 4) After the hot pressing treatment is completed, the sample is cooled to room temperature while maintaining pressure. The sample is then removed to obtain a soft magnetic amorphous alloy with energy state modulation.

2. The method for regulating the energy states of amorphous alloys to enhance soft magnetic properties according to claim 1, characterized in that, Step 1) The amorphous alloy strip is an iron-based, cobalt-based, or nickel-based soft magnetic amorphous alloy strip.

3. The method for regulating the energy states of amorphous alloys to enhance soft magnetic properties according to claim 1, characterized in that, Step 1) The relaxation enthalpy of the amorphous alloy strip is less than 15 J / g.

4. The method for regulating the energy states of amorphous alloys to enhance soft magnetic properties according to claim 1, characterized in that, Step 2) The porous substrate is copper foam, nickel foam, iron foam, titanium foam, aluminum foam, or porous stainless steel, wherein the porosity of the porous substrate is not less than 30%.

5. The method for regulating the energy states of amorphous alloys to enhance soft magnetic properties according to claim 1, characterized in that, Step 3) The heating program and pressurization parameters are as follows: heating temperature 30-200℃, holding time 10-60min, heating rate 5-10℃ / min, and applied pressure 1.0-6.0MPa.

6. The method for regulating the energy states of an amorphous alloy to enhance its soft magnetic properties according to claim 1, characterized in that, Step 4) The cooling method is any one of furnace cooling, air cooling, wind cooling, oil cooling or water cooling.

7. A soft magnetic amorphous alloy, characterized in that, It is prepared by the method described in any one of claims 1-6.

8. The soft magnetic amorphous alloy according to claim 7, characterized in that, The relaxation enthalpy of the soft magnetic amorphous alloy is 20–35 J / g.

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