A method for improving the piezomagnetic coefficient of iron-based amorphous alloys based on pulsed laser technology

Abstract

The present invention discloses a method for improving the piezomagnetic coefficient of an iron-based amorphous alloy based on pulsed laser technology, which belongs to the field of pulsed laser technology. This method uses a pulsed laser beam to etch parallel linear laser marks on the surface of an iron-based amorphous alloy to improve the piezomagnetic coefficient of the iron-based amorphous alloy; wherein the pulsed laser mark spacing is 15 to 30 mm, and the pulsed laser mark width is 5 to 20 mm. The present invention adjusts the laser power, the width and spacing of the periodic linear laser marks, and processes the surface of the iron-based amorphous alloy. The saturation magnetostriction coefficient and the maximum piezomagnetic coefficient are significantly improved, and the material still maintains the characteristics of the amorphous structure and has excellent plasticity.

Description

Technical Field

[0001] The present invention belongs to the field of pulse laser technology, and in particular relates to a method for improving the piezomagnetic coefficient of an iron-based amorphous alloy based on pulse laser technology. Background Art

[0002] Iron-based amorphous alloys are typically formed by rapidly cooling molten metal and suppressing crystallization to create a long-range disordered atomic arrangement. Their material system typically consists of 80% metallic elements such as Fe, Co, and Ni, which ensure ferromagnetism, and the remaining portion of transition elements such as B, Si, and P, which promote amorphous formation. Due to their long-range disorder and short-range order, and the absence of defects such as grain boundaries and dislocations, they possess a range of excellent soft magnetic and magnetostrictive properties, including high saturation magnetization, high permeability, low coercivity, low iron loss, and a high-voltage constant. Furthermore, their high sensitivity to magnetic fields, due to their high-voltage constant, makes them key functional materials in modern industry and technology, widely used in the manufacture of high-precision magnetoelectric sensors and high-performance magnetoelectric antennas.

[0003] Currently, the traditional annealing process is used to enhance the piezomagnetic coefficient of iron-based non-gold alloys. However, although the traditional annealing process can optimize the magnetostrictive properties of iron-based amorphous alloys to a certain extent, improving their magnetoelectric conversion efficiency and stability, the long heating process often leads to uneven heating of the material and difficult-to-control oxidation. In addition, this heating method can significantly increase the brittleness of the material, thus limiting its widespread use in practical applications.

[0004] Compared to traditional annealing processes, pulsed laser processing technology not only effectively avoids a sharp increase in material brittleness with its rapid thermodynamic response, clean non-contact heat source, and highly controllable, specific heat treatment process, but also significantly improves the material's magnetostrictive properties with its simple processing method and excellent enhancement effect. To date, there have been no reports on the use of periodic linear laser scoring to improve the piezomagnetic coefficient of iron-based amorphous alloys. Therefore, there is a need to provide a method for improving the piezomagnetic coefficient of iron-based amorphous alloys using pulsed laser technology. Summary of the Invention

[0005] In response to the above-mentioned problems existing in the prior art, the first technical problem to be solved by the present invention is to provide a method for improving the piezomagnetic coefficient of an iron-based amorphous alloy based on pulsed laser technology. The method has simple processing equipment, simple operation, and low cost. The prepared iron-based amorphous alloy has excellent saturation magnetostriction coefficient and maximum piezomagnetic coefficient. The second technical problem to be solved by the present invention is to provide an iron-based amorphous alloy with improved piezomagnetic coefficient based on pulsed laser technology. The iron-based amorphous alloy has excellent saturation magnetostriction coefficient and maximum piezomagnetic coefficient. The third technical problem to be solved by the present invention is to provide an application of an iron-based amorphous alloy with improved piezomagnetic coefficient based on pulsed laser technology in the field of magnetoelectric sensors and magnetoelectric antennas, so as to improve the sensitivity and performance of magnetoelectric sensors and magnetoelectric antennas.

[0006] In order to solve the above problems, the technical solutions adopted by the present invention are as follows:

[0007] A method for improving the piezomagnetic coefficient of an iron-based amorphous alloy based on pulsed laser technology, wherein a pulsed laser beam is used to etch parallel linear laser marks on the surface of the iron-based amorphous alloy to improve the piezomagnetic coefficient of the iron-based amorphous alloy; wherein the pulsed laser mark spacing is 15 to 30 mm, and the pulsed laser mark width is 5 to 20 mm.

[0008] Furthermore, the central wavelength of the pulse laser is 1064 nm.

[0009] Furthermore, the power of the pulse laser is 5 to 30W.

[0010] Furthermore, the power of the pulse laser is 15W.

[0011] Furthermore, the pulse laser scoring interval is 20 to 25 mm.

[0012] Furthermore, the width of the pulse laser scoring is 10 to 20 mm.

[0013] Furthermore, the fixed laser frequency is 30kHz, the pulse width is 100ns, and the laser scanning speed is 1000mms -1 .

[0014] Furthermore, the laser etching point spacing is 0.2 mm.

[0015] The iron-based amorphous alloy prepared by the method.

[0016] The method is applied in the fields of magnetoelectric sensors and magnetoelectric antennas.

[0017] Beneficial effects: Compared with the prior art, the advantages of the present invention are:

[0018] (1) The present invention processes the surface of the iron-based amorphous alloy by adjusting the laser power, the width and spacing of the periodic linear laser scratches, and thereby significantly improving the saturation magnetostriction coefficient and the maximum piezomagnetic coefficient. The material still maintains the characteristics of the amorphous structure and has excellent plasticity.

[0019] (2) Compared with treatment methods such as isothermal annealing, the material of the present invention still has excellent plasticity. The present invention uses pulsed laser technology with rapid thermodynamic response, clean non-contact heat source and highly controllable specific heat treatment process, which effectively avoids the sharp increase of material brittleness. It also greatly improves the magnetostrictive properties of the material with its simple processing method and excellent improvement effect.

[0020] (3) The processing equipment of the present invention is simple, easy to operate, low in cost and fast in processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is the SEM image of the iron-based amorphous alloy sample after pulsed laser treatment at a laser power of 15W;

[0022] Figure 2 This is the XRD pattern of the Fe-based amorphous alloy sample after pulsed laser treatment at a laser power of 15W;

[0023] Figure 3 This is a graph showing the variation of the saturation magnetostriction coefficient / maximum piezomagnetic coefficient of the samples after treatment with different laser powers according to the present invention;

[0024] Figure 4 This is a graph showing the magnetostriction coefficient test results of samples treated with different laser powers according to the present invention;

[0025] Figure 5 This is a graph showing the maximum piezomagnetic coefficient test results of samples treated with different laser powers according to the present invention;

[0026] Figure 6 This is a graph showing the variation of the saturation magnetostriction coefficient of the sample when the laser scoring spacing is fixed and the scoring width is changed;

[0027] Figure 7 This is a graph showing the variation of the maximum piezomagnetic coefficient of the sample when the laser scoring spacing is fixed and the scoring width is changed;

[0028] Figure 8 This is a graph showing the variation of the saturation magnetostriction coefficient of the sample when the laser scoring width is fixed and the scoring spacing is changed;

[0029] Figure 9 This is a graph showing the variation of the maximum piezomagnetic coefficient of the sample when the laser scoring width is fixed and the scoring spacing is changed;

[0030] Figure 10This is a graph showing the magnetostriction coefficient test results of the sample when the laser scoring spacing is fixed and the scoring width is changed;

[0031] Figure 11 This is a graph showing the magnetostriction coefficient test results of the sample when the laser scoring width is fixed and the scoring spacing is changed;

[0032] Figure 12 This is a graph showing the piezomagnetic coefficient test results of a sample when the laser scoring spacing is fixed and the scoring width is changed;

[0033] Figure 13 This is a graph showing the piezomagnetic coefficient test results of a sample when the laser scoring width is fixed and the scoring spacing is changed;

[0034] Figure 14 This is a comparison chart of the detection limits of weak magnetic fields of the magnetoelectric composite material prepared by the present invention using untreated and pulsed laser-treated iron-based non-gold alloy. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described below in conjunction with specific examples. In the following examples, unless otherwise specified, the technical means used are conventional means well known to those skilled in the art. In the examples, if specific conditions are not specified, they are carried out according to conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used are not specified by the manufacturer, and are all conventional products that can be purchased commercially.

[0036] The iron-based amorphous alloy used in the following examples is sourced from AYFA-M type iron-based amorphous alloy material produced by Qingdao Yunlu Advanced Materials Technology Co., Ltd.

[0037] The fiber laser equipment used in the following examples is a Zhongtian Laser 30W laser marking machine, the center wavelength of which is 1064nm. During the processing, the fixed laser frequency is 30kHz, the pulse width is 100ns, and the laser scanning speed is 1000mms -1 The laser etching point spacing is 0.2mm. By adjusting the laser power, the width and spacing of the periodic linear laser markings, the size of 125×20mm 2 The rectangular Fe-based amorphous alloy surface is processed.

[0038] The following examples use Nanjing Hepu dynamic signal test and analysis system HP-DS8125 to test the change of magnetostriction coefficient (λ) of materials in DC magnetic field of 0-30Oe, and use d 33,m =dλ / dH, calculate its piezomagnetic coefficient (d 33,m ). The magnetostriction coefficient is tested by strain gauge resistance measurement method, and the specific test method is as follows:

[0039] (1) Paste the resistance strain gauge onto the sample after pulse laser treatment;

[0040] (2) The sample is connected to form a current loop and placed in the central area of ​​the customized Helmholtz coil; the DC power supply is ITECH IT6302 DC power supply, and its output current range is 0-3A; the coil constant of the customized Helmholtz coil is K B =10Oe / A, can generate a DC magnetic field of 0-30Oe;

[0041] (3) During the magnetic field change, the strain Δl / l of the sample under the action of the external magnetic field is transmitted to the resistance strain gauge through force and converted into resistance change ΔR / R. The characteristics of the strain gauge are ΔR=R i -R, where K is the gauge factor of the resistance strain gauge, R is the resistance of the strain gauge when there is no external magnetic field, and R i The resistance of the strain gauge when there is an external magnetic field. The magnetostriction coefficient of the sample can be obtained by the resistance change of the strain gauge. Then the corresponding relationship between the magnetostriction coefficient of the sample and the magnetic field intensity is obtained;

[0042] (4) According to the corresponding relationship between magnetostriction coefficient and magnetic field intensity, use d 33,m =dλ / dH, the corresponding relationship between the piezomagnetic coefficient and the magnetic field intensity can be obtained.

[0043] Example 1

[0044] The method of improving the piezomagnetic coefficient of iron-based amorphous alloys with different laser powers based on pulsed laser technology is as follows:

[0045] Using fiber laser equipment to produce a 125×20mm 2 The rectangular iron-based non-gold alloy surface is etched with parallel linear laser marks using a pulsed laser beam, wherein the fixed laser frequency is 30kHz, the pulse width is 100ns, and the laser scanning speed is 1000mms -1 The laser etching point spacing is 0.2mm, the pulse laser center wavelength is 1064nm, the fixed groove spacing is 25mm, the groove width is 10mm, and the laser power is set to 5W, 10W, 15W, 20W, 25W and 30W respectively. Six groups of samples treated with different pulse laser powers are obtained. The samples are characterized by SEM and XRD. The results are shown in the figure. Figure 1 and 2 The six groups of samples after treatment were attached with resistance strain gauges and placed in a DC magnetic field of 0-30Oe to test their magnetostriction coefficients. The results are shown in Table 1 and Figures 3-5 shown.

[0046] Table 1 Saturation magnetostriction coefficient and maximum piezomagnetic coefficient of samples treated with different laser powers and their percentage change compared with the unmarked sample

[0047]

[0048] Depend on Figure 1 It can be seen that by using a scanning electron microscope (SEM) to characterize the iron-based amorphous alloy sample after pulse laser treatment, periodically arranged laser scoring points with a diameter of 70 μm can be observed.

[0049] Depend on Figure 2 It can be seen that the iron-based amorphous alloy sample after pulse laser treatment is characterized by X-ray diffraction (XRD), and the iron-based amorphous alloy still maintains the amorphous structure characteristics.

[0050] Depend on Figures 3-5 As shown in Table 1, the samples treated with pulsed lasers of varying powers exhibited significant changes in their saturation magnetostriction coefficient and maximum piezomagnetic coefficient compared to the untreated samples, generally increasing first and then decreasing. When the laser power was 15W, both the saturation magnetostriction coefficient and the maximum piezomagnetic coefficient increased the most. When measuring the saturation magnetostriction coefficient of the sample, its maximum magnetostriction coefficient increased from 24.84ppm to 34.76ppm, an increase of 39.94%. When calculating the maximum piezomagnetic coefficient of the sample, its maximum piezomagnetic coefficient increased from 5.85ppm / Oe to 11.23ppm / Oe, an increase of 91.97%.

[0051] Example 2

[0052] The method of improving the piezomagnetic coefficient of iron-based amorphous alloys with different laser scoring widths / spacings based on pulsed laser technology is as follows:

[0053] Using fiber laser equipment to produce a 125×20mm 2 The rectangular iron-based non-gold alloy surface is etched with parallel linear laser marks using a pulsed laser beam, wherein the fixed laser frequency is 30kHz, the pulse width is 100ns, and the laser scanning speed is 1000mms -1 The laser etching point spacing is 0.2mm, the pulse laser center wavelength is 1064nm, the fixed laser power is 15W, the scratch spacing is set to 15mm, 20mm, 25mm and 30mm, and the scratch width is 5mm, 10mm, 15mm and 20mm, respectively. 16 groups of samples with different pulse laser spacing and widths are obtained.

[0054] The 16 groups of samples after pulse laser treatment were attached with resistance strain gauges and placed in a DC magnetic field of 0-30Oe to test their magnetostriction coefficients and calculate their piezomagnetic coefficients. The results are shown in Tables 2, 3 and Figures 6 to 13Table 2 Saturation magnetostriction coefficient of samples after different laser scoring parameters and the percentage change compared with the unscored sample

[0055]

[0056] Table 3 Maximum piezomagnetic coefficients of samples treated with different laser scoring parameters and percentage changes compared to unscored samples

[0057]

[0058]

[0059] From Tables 2, 3 and Figures 6 to 13 It can be seen that the saturation magnetostriction coefficient and maximum piezomagnetic coefficient of samples treated with pulsed lasers of different scoring spacing and widths show significant changes compared to untreated samples. When the laser scoring spacing is fixed and the laser scoring width is increased, the saturation magnetostriction coefficient of the sample generally increases, and the maximum piezomagnetic coefficient generally increases first and then decreases. When the laser scoring width is fixed and the laser scoring spacing is increased, the saturation magnetostriction coefficient and maximum piezomagnetic coefficient of the sample generally increase first and then decrease. Among them, when the scoring spacing is 20-25mm and the scoring width is 10-20mm, the saturation magnetostriction coefficient and maximum piezomagnetic coefficient of the sample increase relatively significantly. When measuring the sample's saturation magnetostriction coefficient, its maximum saturation magnetostriction coefficient increased from 24.84ppm to 34.77ppm, an increase of 39.98%. When calculating the sample's maximum piezomagnetic coefficient, its maximum piezomagnetic coefficient increased from 5.85ppm / Oe to 11.06ppm / Oe, an increase of 89.06%. In summary, the method described in the present invention can effectively improve the piezomagnetic coefficient of iron-based amorphous alloy materials.

[0060] Example 3

[0061] The method of improving the weak magnetic detection capability of magnetoelectric composite materials with iron-based amorphous alloys based on pulsed laser technology is as follows:

[0062] 1) Principle of weak magnetic detection of magnetoelectric composite materials:

[0063] The magnetoelectric composite material is based on the magnetoelectric coupling effect. It uses magnetostrictive materials (iron-based amorphous alloys) to generate magnetostrictive strain under the action of an external magnetic field, and uses strain coupling at the interface to transfer the elastic strain to the piezoelectric material (PZT-5H). This induces bound charges on the surface of the piezoelectric material, thereby realizing the conversion of external weak magnetic signals into electrical signals.

[0064] 2) Preparation process of magnetoelectric composite materials:

[0065] The use size is 125×20mm2 The rectangular iron-based non-gold alloy surface is etched with parallel linear laser marks using a pulsed laser beam, wherein the fixed laser frequency is 30kHz, the pulse width is 100ns, and the laser scanning speed is 1000mms -1 , the laser etching point spacing is 0.2mm, the pulse laser center wavelength is 1064nm, the fixed laser power is 15W, the fixed groove spacing is 25mm, the groove width is 10mm, and 24 groups of pulse laser processed samples are obtained. Use epoxy resin 105 / 206 to bond each group of 3 samples and dry them at a constant temperature of 50℃ for 8 hours, for a total of 8 groups. Use epoxy resin 105 / 206 to bond the dried samples to a 40×20mm 2 The piezoelectric material (PZT-5H) was bonded to form a magnetoelectric composite material with an LT structure: iron-based non-gold alloy / piezoelectric ceramic / iron-based non-gold alloy. The composite was dried at 50°C for 8 hours. Four groups were prepared, labeled Samples 5-8. Simultaneously, four groups of magnetoelectric composite materials made from untreated iron-based non-gold alloy were prepared using the same process for subsequent comparative testing. These were labeled Samples 1-4.

[0066] The present invention tests the magnetoelectric charge coefficient of the magnetoelectric composite material prepared from the untreated and pulsed laser treated iron-based non-gold alloy. The effective value of the charge induced on the sample is measured by a charge amplifier and combined with the effective value of the applied AC magnetic field. The magnetoelectric charge coefficient was determined. The results are shown in Tables 4 and 5.

[0067] Table 4 Performance parameters of magnetoelectric composite materials using untreated Fe-based amorphous alloys

[0068]

[0069] Table 5 Performance parameters of the magnetoelectric composites of Fe-based amorphous alloys processed by pulsed laser

[0070]

[0071] As shown in Tables 4 and 5, the average magnetoelectric charge coefficient of the four groups of untreated iron-based amorphous alloys in the quasi-static state (1kHz) was 3425.3 pC / Oe, while the average magnetoelectric charge coefficient of the four groups of iron-based amorphous alloys treated with pulsed lasers was 4856.8 pC / Oe, an improvement of 41.79%. This demonstrates that pulsed laser treatment of iron-based amorphous alloys can improve the magnetic field detection capability of magnetoelectric composites, indicating that the present invention has important application value in the manufacture of highly sensitive magnetoelectric sensors and high-performance magnetoelectric antennas.

[0072] Based on the comparison of the magnetoelectric charge coefficients of the magnetoelectric composite materials prepared from the untreated and pulsed laser treated iron-based amorphous alloys, the present invention also conducts a comparative test on the detection limit capabilities of the two magnetoelectric composite materials to weak magnetic fields. The two magnetoelectric composite materials are placed in an environment where an external AC signal source (weak magnetic field to be measured) is applied, and the electrical response signals of the magnetoelectric composite materials are detected by a lock-in amplifier (UHFLI600MHz). The results are as follows: Figure 14 shown.

[0073] Depend on Figure 14 The detection limit of the magnetoelectric composite material prepared from the untreated iron-based amorphous alloy for weak magnetic fields is 368 pT, while the detection limit of the magnetoelectric composite material prepared from the pulsed laser-treated iron-based amorphous alloy for weak magnetic fields is 123 pT, which is one-third of the weak magnetic field detection limit of the untreated sample. This result not only further verifies the effectiveness of pulsed laser technology in improving the piezomagnetic coefficient of iron-based amorphous alloys, but also fully demonstrates the important role of this technology in improving the weak magnetic detection capabilities of magnetoelectric composite materials.

[0074] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for improving the piezomagnetic coefficient of an iron-based amorphous alloy based on pulsed laser technology, characterized in that: A pulsed laser beam is used to etch parallel linear laser grooves on the surface of the iron-based amorphous alloy to improve the piezomagnetic coefficient of the iron-based amorphous alloy. The pulsed laser groove spacing is 20-25 mm; the pulsed laser groove width is 10-20 mm; the pulsed laser center wavelength is 1064 nm; the pulsed laser power is 15 W; the fixed laser frequency is 30 kHz, the pulse width is 100 ns, and the laser scanning speed is 1000 mm / s. -1 ; The laser etching point spacing is 0.2mm.

2. The iron-based amorphous alloy prepared by the method according to claim 1.

3. Application of the method according to claim 1 in the field of magnetoelectric sensors and magnetoelectric antennas.

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