An underwater acoustic transducer

Abstract

This invention discloses an underwater acoustic transducer. It includes a steel circular base, and Mn is disposed on the steel circular base. 1‑x Ni x A CoSi / epoxy resin magnetostrictive composite cylindrical rod, wherein x is between 0.012 and 0.015; two N52 type permanent magnets are also provided on the base; the height of the magnetostrictive composite cylindrical rod is 180±5mm and the diameter is 4±0.5mm; the two N52 type permanent magnets are both 180±5mm high, with a square cross-section of 5mm side length, and the N and S poles of the two N52 type permanent magnets are arranged opposite each other on both sides of the magnetostrictive composite cylindrical rod, and the distance between the two N52 type permanent magnets is 6±0.5mm; it also includes a soft magnetic steel shell with a height of 180±5mm placed on the base, forming a closed magnetic circuit; a coil is wound around the periphery of the magnetostrictive composite cylindrical rod. The underwater acoustic transducer of the present invention uses Mn 1‑x Ni x The CoSi / epoxy resin magnetostrictive composite material, along with the matching permanent magnet, achieves a simple structure, low cost, corrosion resistance, and low eddy current loss.

Description

Technical Field

[0001] This invention belongs to the field of transducers, and specifically relates to an underwater acoustic transducer. Background Technology

[0002] An underwater acoustic transducer is a device that uses low-frequency sound waves to detect and identify underwater targets. Underwater acoustic transducers based on magnetostrictive materials utilize the vibration generated by the material's response to an alternating magnetic field. When the vibration frequency equals the natural frequency of the output rod, resonance maximizes the mechanical wave amplitude, thereby achieving the output of strong sound waves. Tb-Dy-Fe alloy is a commercially available, high-performance magnetostrictive material that has been used in the manufacture of underwater acoustic transducers for submarines. However, due to its high cost and poor corrosion resistance, research into developing new magnetostrictive materials and their transducers remains crucial. Summary of the Invention

[0003] The purpose of this invention is to provide a method based on Mn 1-x Ni x A hydroacoustic transducer made of CoSi / epoxy resin magnetostrictive composite material is used to convert electrical energy into mechanical energy.

[0004] The technical solution to achieve the purpose of this invention is: a hydroacoustic transducer, comprising a steel circular base, and Mn disposed on the steel circular base. 1-x Ni x A CoSi / epoxy resin magnetostrictive composite cylindrical rod, wherein x is between 0.012 and 0.015; two N52 type permanent magnets are also provided on the base; the height of the magnetostrictive composite cylindrical rod is 180±5mm and the diameter is 4±0.5mm; the height of the two N52 type permanent magnets is 180±5mm, the cross-section is a square with a side length of 5mm, the N pole and S pole of the two N52 type permanent magnets are arranged opposite each other on both sides of the magnetostrictive composite cylindrical rod, and the distance between the two N52 type permanent magnets is 6±0.5mm; it also includes a soft magnetic steel shell with a height of 180±5mm placed on the base to form a closed magnetic circuit; a coil is wound around the periphery of the magnetostrictive composite cylindrical rod.

[0005] Furthermore, the diameter of the circular base is 40-45mm and the thickness is greater than 20mm.

[0006] Furthermore, the outer coil of the magnetostrictive composite cylindrical rod is made of copper wire.

[0007] Furthermore, Mn 1-x Ni x The epoxy resin accounts for 15% of the mass of the CoSi / epoxy resin magnetostrictive composite material.

[0008] Furthermore, Mn 1-x Nix The CoSi / epoxy magnetostrictive composite material has a

[100] texture.

[0009] Furthermore, Mn 1-x Ni x The CoSi / epoxy resin magnetostrictive composite material was prepared using the following steps:

[0010] The elements Mn, Ni, Co, and Si are arc-melted; the uniformly molten ingot is then annealed; the resulting ingot is then ground into powder; finally, the powder is mixed with epoxy resin in a certain proportion and rotated at an angular velocity of 30-120 rpm while being placed under a transverse static magnetic field to complete the curing process.

[0011] Furthermore, the purity of elemental Mn, Ni, Co, and Si is greater than 99.99%.

[0012] Furthermore, the specific process of annealing is as follows: annealing at 800-850 degrees Celsius for 48-60 hours, followed by slow cooling to room temperature for 72 hours.

[0013] Furthermore, the powder produced by grinding the ingots has a size between 300 and 600 mesh.

[0014] Furthermore, the magnetic induction intensity of the static magnetic field in "curing is completed under a transverse static magnetic field" is greater than 1T.

[0015] The working principle of the underwater acoustic transducer of the present invention is as follows: a permanent magnet provides a DC magnetic field to the magnetostrictive composite material, so that the material works in the magnetostrictive linear region; then an AC magnetic field is applied to the magnetostrictive material to generate vibration; when the vibration frequency is equal to the natural frequency of the output rod, resonance occurs and the amplitude is maximized; the mechanical wave generated during resonance is emitted from one end of the rod and used to detect underwater targets.

[0016] Compared with the prior art, the significant advantages of this invention are:

[0017] This invention mixes Ni-doped MnCoSi alloy powder with epoxy resin at a mass ratio of 85:15 and uses magnetic field orientation technology to prepare a Mn1-xNixCoSi / epoxy resin composite material with a

[100] texture. The magnetostriction of this material is comparable to that of commercial Terfenol-D and is independent of the magnetic field direction. It also has the advantages of low price, low eddy current loss and strong corrosion resistance, making it more suitable for underwater acoustic transducers than Terfenol-D.

[0018] Furthermore, this invention utilizes the aforementioned composite material and a commercially available N52 type permanent magnet, placing the permanent magnet on both sides of the magnetostrictive composite material to create the output rod of the underwater acoustic transducer; the natural vibration frequency of this rod is as low as kiloHz, thus meeting the requirements of underwater detection; compared to the traditional Terfenol-D underwater acoustic transducer, this invention does not require connecting the magnetostrictive material and the permanent magnet in series to form a rod, thus having a simpler device structure. Attached Figure Description

[0019] Figure 1 These are the magnetization curves of Mn0.988Ni0.012CoSi bulk (a) and powder (b).

[0020] Figure 2 The results are electron backscattering test results of Mn0.988Ni0.012CoSi / epoxy resin composite material; (a) is a scanning electron microscope image of the composite material; (b) is the inverse pole figure of the cross section shown in (a); and (c) is the {100}, {010} and {001} pole figures of the cross section shown in (a).

[0021] Figure 3 The results show the magnetostriction measurements of magnetostrictive composite materials with different epoxy resin contents; (a) 15%; (b) 20%; (c) 30%; and (d) 40%.

[0022] Figure 4 It refers to the magnetostriction of magnetostrictive materials under the action of transverse and axial magnetic fields, which proves that the magnetostriction of materials does not depend on the direction of the magnetic field.

[0023] Figure 5 The magnetic flux density distribution of the permanent magnet / magnetostrictive composite material / permanent magnet unit is shown in (a) unclosed and (b) closed magnetic circuit conditions.

[0024] Figure 6 This is a schematic diagram of the structure of a traditional Terfenol-D underwater acoustic transducer.

[0025] Figure 7 This is a structural diagram of the underwater acoustic transducer of the present invention.

[0026] Figure 8 yes Figure 7 Perspective view.

[0027] Figure 9 It refers to the operating frequency and displacement of the 180mm output rod under a 50Oe AC magnetic field. Detailed Implementation

[0028] The present invention will now be described in further detail with reference to the accompanying drawings.

[0029] Example 1

[0030] A method based on Mn 1-x Ni x A CoSi / epoxy resin magnetostrictive composite underwater acoustic transducer. Its specific structure is as follows: Figure 7-8 As shown, it includes a circular base and uses Mn 1-x Ni x A cylindrical rod made of CoSi / epoxy resin magnetostrictive composite material, N52 type permanent magnets laterally arranged on both sides of the cylindrical rod, a coil wound around the outer circumference of the cylindrical rod, and a soft magnetic steel outer shell surrounding it. The fabrication process of the underwater acoustic transducer is as follows:

[0031] 1. Mix 99.99% pure Mn, Ni, Co, and Si elements according to Mn... 1-x Ni x The CoSi (x = 0.012-0.015) mixture was prepared and then subjected to electric arc melting. The ingot, after being uniformly melted, was annealed at 850 degrees Celsius for 60 hours, and then slowly cooled to room temperature for 72 hours.

[0032] 2. Grind the obtained ingots into powder, and then sieve out the powder with a size between 300-600 mesh.

[0033] 3. Mix the powder with epoxy resin (15% by mass) and rotate it at an angular velocity of 30 rpm while placing it under a 1T external transverse static magnetic field to complete the curing.

[0034] 4. The obtained composite magnetostrictive material is processed into a cylinder with a length of 180mm and a diameter of 4mm, and fixed on a steel circular base with a diameter of 5mm and a thickness of 20mm.

[0035] 5. Place N52 type permanent magnets with a length of 180mm and a width and thickness of 5mm on both sides of the cylindrical magnetostrictive composite material; the N poles and S poles of the two permanent magnets are opposite each other and the distance between them is 6mm.

[0036] 6. Place a soft magnetic steel shell with a height of 180mm on the base to form a closed magnetic circuit.

[0037] 7. Wrap a coil around the outside of the rod to excite the output rod to vibrate.

[0038] The annealed ingot and the ground powder were respectively loaded into a commercial multi-property measurement platform (PPMS), and the relationship between magnetization and the applied magnetic field was measured using a vibrating sample magnetometer (VSM). The results are as follows: Figure 1 The Mn shown 0.988 Ni 0.012 Magnetization curves of CoSi bulk (a) and powder (b). From Figure 1It can be concluded that the material exhibits obvious variable magnetism, which is the origin of the material's magnetostriction.

[0039] The fully cured magnetostrictive composite material was radially cut, ion-polished, and the preferred orientation was identified using the electron backscattering function of a scanning electron microscope, yielding Mn. 0.988 Ni 0.012 The electron backscattering test results of the CoSi / epoxy resin composite are as follows: Figure 2 As shown, from Figure 2 It can be concluded that there is a

[100] texture, and the presence of the texture helps to enhance the magnetostrictive effect of the material.

[0040] The fully cured magnetostrictive composite material was cut axially, and strain gauges were attached to the sample surface, parallel and perpendicular to the texture direction, respectively. The relationship between the strain gauge resistance and the magnetic field was then measured using PPMS to obtain the magnitude of the magnetostriction. The results are as follows: Figure 3 The result shown in (a)

[0041] In addition, for comparison, magnetostriction measurement results for composite materials with epoxy resin content of 20%, 30%, and 40% by mass are shown below. Figure 3 As shown in (b), (c) and (d), it can be concluded from the figures that, at room temperature, the composite material containing 15% epoxy resin has a saturation magnetostriction greater than 1500 ppm, comparable to that of commercial Tb-Dy-Fe alloys.

[0042] exist Figure 3 (a) Based on the measurement method, the magnetic field is adjusted to be transverse to obtain, as shown in... Figure 4 The figure shows the magnetostriction of a magnetostrictive material under transverse and axial magnetic fields. As can be seen from the figure, the magnetostriction of the material is independent of the direction of the magnetic field.

[0043] Figure 5 This is a magnetic flux density distribution diagram of the permanent magnet / magnetostrictive composite material / permanent magnet unit, obtained through COMSOL simulation. The diagram shows that when the permanent magnet spacing is 6 mm, the magnetic flux density inside the magnetostrictive composite material reaches 0.84 T in the closed loop condition, which is in the linear magnetostrictive region (or the optimal operating region).

[0044] Figure 6 This is a schematic diagram of a traditional Terfenol-D underwater acoustic transducer. It contains four output rods, and each output rod consists of multiple short Terfenol-D rods connected in series with a cylindrical permanent magnet.

[0045] Figure 7 This is a structural diagram of the underwater acoustic transducer of the present invention. At its center is a complete magnetostrictive rod, and on both sides of the rod are cuboid N52 type permanent magnets. The outer perimeter is a soft magnetic shell.

[0046] Figure 8 yes Figure 7 Perspective view.

[0047] Figure 9 The figure shows the operating frequency and displacement of the 180mm output rod under a 50Oe AC magnetic field, obtained through COMSOL simulation. The figure indicates that the resonant frequency is between 1585-1605Hz, and the maximum displacement at resonance is 8mm.

[0048] Example 2

[0049] Mn, Ni, Co, and Si elements with a purity of 99.99% were selected according to the Mn... 1-x Ni x CoSi (x = 0.012-0.015) was mixed and arc-melted. The homogenized ingot was annealed at 800°C for 48 hours, followed by slow cooling to room temperature for 72 hours. The resulting ingot was then ground into powder with a size between 300-600 mesh and mixed with epoxy resin (15% by mass). The mixture was then rotated at an angular velocity of 120 rpm and placed under a 1T external transverse static magnetic field for curing. The resulting composite magnetostrictive material was then processed into a cylinder 180 mm long and 4 mm in diameter, and fixed onto a steel circular base with a diameter of 40 mm and a thickness of 25 mm. Further, N52 type permanent magnets, each 180 mm long, 5 mm wide, and 5 mm thick, were placed on both sides of the cylindrical magnetostrictive composite material; the N poles of the two permanent magnets were opposite each other, with a spacing of 6 mm. Finally, a soft magnetic steel shell with a height of 180mm is placed on the base to form a closed magnetic circuit, and a coil is wound around the outside of the rod to excite the output rod to vibrate.

[0050] The above embodiments are implementation methods of the present invention, but the implementation methods of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications that do not depart from the spirit and principle of the present invention should be considered equivalent substitutions and are included within the protection scope of the present invention.

Claims

1. A hydroacoustic transducer, characterized in that, Includes a steel circular base, and Mn set on the steel circular base. 1- x Ni x A CoSi / epoxy resin magnetostrictive composite cylindrical rod, wherein x is between 0.012 and 0.015; two N52 type permanent magnets are also provided on the base; the height of the magnetostrictive composite cylindrical rod is 180±5mm and the diameter is 4±0.5mm; the height of the two N52 type permanent magnets is 180±5mm, and the cross-section is a square with a side length of 5mm. The N pole and S pole of the two N52 type permanent magnets are arranged opposite each other on both sides of the magnetostrictive composite cylindrical rod, and the distance between the two N52 type permanent magnets is 6±0.5mm; it also includes a soft magnetic steel shell with a height of 180±5mm placed on the base to form a closed magnetic circuit; a coil is wound around the periphery of the magnetostrictive composite cylindrical rod; The diameter of the circular base is 40-45mm and the thickness is greater than 20mm; The outer coil of the magnetostrictive composite cylindrical rod is made of copper wire. The Mn 1-x Ni x In the CoSi / epoxy resin magnetostrictive composite material, the epoxy resin accounts for 15% of the mass. The Mn 1-x Ni x The CoSi / epoxy magnetostrictive composite material has a [100] texture. The Mn 1-x Ni x CoSi / epoxy resin magnetostrictive composite material is made of Mn 1-x Ni x CoSi alloy powder is mixed with epoxy resin in a certain proportion and cured under angular velocity rotation conditions of 30-120 rpm and a transverse static magnetic field to obtain the product; the Mn 1-x Ni x The size of the CoSi alloy powder is between 300 and 600 mesh.

2. The underwater acoustic transducer according to claim 1, characterized in that, The magnetic induction intensity of the transverse static magnetic field is greater than 1T.

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