A magnetic plate assembly, a sound-generating device, and an electronic device.

Abstract

This invention discloses a magnetically conductive plate assembly, a sound-generating device, and an electronic device, relating to the field of acoustic technology. The magnetically conductive plate assembly includes a body portion and a coating disposed on the surface of the body portion. The coating includes the main body portion and reinforcing nanoparticles distributed within the main body portion. The main body portion is composed of a polycrystalline material and contains at least one element selected from iron, cobalt, and nickel. The mass percentage of the reinforcing nanoparticles in the coating is 0.1% to 20%, the maximum size of the reinforcing nanoparticles is less than or equal to 5 μm, the elastic modulus of the reinforcing nanoparticles is 300 to 1000 GPa, the hardness of the coating is 200 to 2000 Hv, and the coefficient of friction of the coating is 0.1 to 2. The magnetically conductive plate assembly of this invention aims to solve the technical problem of how to improve the mechanical and magnetic properties of a magnetically conductive plate assembly.

Description

Technical Field

[0001] This invention relates to the field of acoustics, and more particularly to a magnetic plate assembly, a sound-generating device, and an electronic device. Background Technology

[0002] As consumer electronics products rapidly evolve towards ultra-thin and lightweight designs, the thickness of speakers, the core sound-generating components of devices such as mobile phones and augmented reality (AR) glasses, is decreasing daily. The magnetic circuit structure is a crucial component determining the speaker's driving force and directly affects its frequency response characteristics. Typically, the magnetic circuit structure includes a frame, a magnet mounted on the frame, and a washer mounted on the magnet. The magnet is a permanent magnet, providing the working magnetic field; the frame and washer are made of soft magnetic materials and serve as magnetic conductors. Together, they constitute a complete magnetic circuit.

[0003] Currently, magnetic plate assemblies (i.e., frames and washer) mostly use iron-based materials such as SPCC (cold-rolled steel sheet). However, these materials have shortcomings in terms of hardness and wear resistance, and are prone to deformation and scratches during product manufacturing and testing, resulting in lattice distortion on the surface, which in turn affects the magnetic conductivity of the material, reduces the working stability of the magnetic circuit structure and the overall acoustic performance of the speaker. Summary of the Invention

[0004] The main objective of this invention is to provide a magnetic plate assembly, a sound-generating device, and an electronic device, aiming to solve the technical problem of how to improve the mechanical properties and magnetic conductivity of the magnetic plate assembly.

[0005] To achieve the above objectives, embodiments of the present invention provide a magnetic conductive plate assembly, the magnetic conductive plate assembly comprising: a body portion and a coating disposed on the surface of the body portion, the coating comprising a main body portion and reinforcing nanoparticles distributed within the main body portion, the main body portion being composed of a polycrystalline material, the main body portion containing at least one element selected from iron, cobalt, and nickel, the mass percentage of the reinforcing nanoparticles in the coating being 0.1% to 20%, the maximum size of the reinforcing nanoparticles being less than or equal to 5 μm, the elastic modulus of the reinforcing nanoparticles being 300 to 1000 GPa, the hardness of the coating being 200 to 2000 Hv, and the coefficient of friction of the coating being 0.1 to 2.

[0006] In one embodiment, the reinforcing nanoparticles include at least one of graphene, carbon nanotubes, boron nitride, boron carbide, and aluminum nitride.

[0007] In one embodiment, the graphene includes at least one of intrinsic graphene, graphene oxide, reduced graphene oxide, and surface-modified graphene.

[0008] In one embodiment, the thickness of the graphene is less than or equal to 100 nm.

[0009] In one embodiment, the ratio of the graphene sheet diameter to its thickness is greater than or equal to 100.

[0010] In one embodiment, the tensile strength of the graphene is 1~150 GPa.

[0011] In one embodiment, the carbon nanotubes include at least one of single-walled carbon nanotubes, multi-walled carbon nanotubes, and surface-modified carbon nanotubes.

[0012] In one embodiment, the outer diameter of the carbon nanotube is less than or equal to 50 nm.

[0013] In one embodiment, the ratio of the length to the outer diameter of the carbon nanotube is greater than or equal to 200.

[0014] In one embodiment, the tensile strength of the carbon nanotubes is 40~200 GPa.

[0015] In one embodiment, the specific surface area of ​​the enhanced nanoparticles is 100~3000 m². 2 / g.

[0016] In one embodiment, the enhanced nanoparticles include at least one of sheet-like and tubular shapes.

[0017] In one embodiment, the enhanced nanoparticles are modified with a surfactant, the surfactant including at least one of cationic surfactants, anionic surfactants, nonionic surfactants, and compound surfactants.

[0018] In one embodiment, the average thickness of the coating is less than or equal to 20% of the average thickness of the body portion.

[0019] In one embodiment, the average thickness of the coating is 1 to 50 μm.

[0020] In one embodiment, the saturation magnetization of the coating is 10~2000 emu / cm. 3 .

[0021] To achieve the above objectives, embodiments of the present invention provide a sound-generating device, the sound-generating device including a housing and a magnetic circuit structure disposed on the housing, the magnetic circuit structure including a magnet assembly and a magnetic guide plate assembly as described above, the magnetic guide plate assembly including at least one of a magnetic guide yoke and a magnetic guide plate disposed at one end of the magnet assembly away from the magnetic guide yoke.

[0022] To achieve the above objectives, embodiments of the present invention provide an electronic device, which includes the magnetic plate assembly described above, or the sound-generating device described above.

[0023] This invention provides a magnetic conductive plate assembly, comprising: a body portion and a coating disposed on the surface of the body portion. The coating includes the body portion and reinforcing nanoparticles distributed within the body portion. The body portion is composed of a polycrystalline material and contains at least one element selected from iron, cobalt, and nickel. The mass percentage of the reinforcing nanoparticles in the coating is 0.1% to 20%, the maximum size of the reinforcing nanoparticles is less than or equal to 5 μm, the elastic modulus of the reinforcing nanoparticles is 300 to 1000 GPa, the hardness of the coating is 200 to 2000 Hv, and the coefficient of friction of the coating is 0.1 to 2. In this invention, by providing a coating containing reinforcing nanoparticles on the surface of the body portion and ensuring that the body portion of the coating contains at least one ferromagnetic element selected from iron, cobalt, and nickel, the coating possesses excellent magnetic permeability, effectively maintaining or even optimizing the magnetic flux efficiency of the magnetic conductive plate assembly, thereby maintaining or even optimizing the acoustic performance of the loudspeaker. By controlling the mass percentage of reinforcing nanoparticles to 0.1–20%, limiting their maximum size to below 5 μm, and setting their elastic modulus to 300–1000 GPa, the reinforcing nanoparticles can be uniformly distributed within the polycrystalline matrix without agglomeration. This results in significant dispersion strengthening and second-phase strengthening effects, allowing the coating to effectively hinder dislocation movement. Consequently, while maintaining the high magnetic permeability of the substrate, the mechanical properties are significantly improved. The coating hardness is increased to 200–2000 Hv, giving the magnetic plate assembly excellent resistance to deformation and scratches, effectively reducing surface lattice distortion during manufacturing and testing. Furthermore, the coefficient of friction of the coating is controlled between 0.1 and 2, giving the magnetic plate assembly appropriate wear resistance. This resists wear and scratches during handling without being too smooth, which could affect the spread and bonding reliability of the adhesive between the assembly and other components in the magnetic circuit structure (e.g., magnets). In this embodiment of the invention, the above technical solution enables the magnetic plate assembly to achieve ultra-thinness and lightweight while possessing excellent mechanical stability and magnetic permeability. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the magnetic conductive plate assembly involved in the embodiment of the present invention; Figure 2 This is a schematic diagram of the sound-generating device involved in an embodiment of the present invention.

[0025] Explanation of reference numerals in the attached figures 100. Magnetic plate assembly; 101. Body; 102. Coating; 103. Reinforcing nanoparticles; 101a, Central magnetic plate; 101b, Side magnetic plate; 101c, Magnetic yoke; 200. Sound-generating device; 201. Housing; 202. Magnetic gap; 203. Diaphragm assembly; 204. Voice coil; 205a, center magnet; 205b, side magnet.

[0026] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0028] Hereinafter, embodiments of the magnetic plate assembly, sound-generating device, and electronic device of the present invention are disclosed in detail with appropriate reference to the accompanying drawings. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repetitive descriptions of practically identical structures may be omitted. This is to avoid unnecessarily lengthy descriptions and to facilitate understanding by those skilled in the art. Furthermore, the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present invention and are not intended to limit the subject matter of the claims.

[0029] The "range" disclosed in this invention is defined in the form of a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60~120 and 80~110 are listed for specific parameters, it is understood that ranges of 60~110 and 80~120 are also expected. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1~3, 1~4, 1~5, 2~3, 2~4, and 2~5. In this invention, unless otherwise stated, the numerical range "a~b" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0~5" indicates that all real numbers between "0~5" have been listed in this article; "0~5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0030] Unless otherwise specified, all embodiments and optional embodiments of the present invention can be combined with each other to form new technical solutions.

[0031] Unless otherwise specified, all steps of the present invention may be performed sequentially or randomly, preferably sequentially. For example, if the method includes steps (a) and (b), it means that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, if the method may also include step (c), it means that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0032] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, the technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and embodiments. However, the present invention is not limited to the listed embodiments, but should also include any other known modifications within the scope of the claims of the present invention.

[0033] To better understand the technical solution of the present invention, a detailed description will be provided below in conjunction with the accompanying drawings and specific embodiments.

[0034] In conventional technology, the magnetic circuit structure in a loudspeaker typically includes a frame, a magnet mounted on the frame, and a washer mounted on the magnet. The frame and washer are usually made of soft magnetic materials such as SPCC (cold-rolled steel sheet) or iron-cobalt alloy. However, these materials have drawbacks such as poor hardness and wear resistance, making them prone to deformation and scratches during manufacturing and testing. This leads to lattice distortion on the surface, affecting the material's magnetic conductivity and reducing the operational stability of the magnetic circuit structure and the overall acoustic performance of the loudspeaker.

[0035] Therefore, embodiments of the present invention provide a magnetic guide plate assembly, with reference to... Figure 1 The magnetic plate assembly 100 includes a body portion 101 and a plating layer 102 disposed on the surface of the body portion 101. The plating layer 102 includes a main body portion and reinforcing nanoparticles 103 distributed within the main body portion. The main body portion is composed of a polycrystalline material and contains at least one element selected from iron, cobalt, and nickel. The mass percentage of the reinforcing nanoparticles 103 in the plating layer 102 is 0.1% to 20%. The maximum size of the reinforcing nanoparticles 103 is less than or equal to 5 μm. The elastic modulus of the reinforcing nanoparticles 103 is 300 to 1000 GPa. The hardness of the plating layer 102 is 200 to 2000 Hv. The coefficient of friction of the plating layer 102 is 0.1 to 2.

[0036] Optionally, the plating layer 102 may be disposed on at least one surface of the body portion 101; for example, the plating layer 102 may be disposed on at least one of the upper surface, lower surface and side surface of the body portion 101.

[0037] Optionally, the magnetic plate assembly 100 includes at least one of a magnetic yoke and a magnetic plate.

[0038] Optionally, the body part 101 is a basic structural component in the magnetic plate assembly 100 that plays a role in bearing and guiding magnetism, and it is itself a magnetic guiding component in the magnetic circuit structure.

[0039] It should be noted that the magnetic plate assembly 100 in this embodiment of the invention is a magnetically conductive component applied in the magnetic circuit structure of a sound-generating device (e.g., a loudspeaker) and having the aforementioned plating layer 102 on its surface. The magnetic plate assembly 100 can be understood as an integral component formed by the formation of the plating layer 102 on the surfaces of the magnetic yoke (i.e., the frame) and / or the magnetic plate (i.e., the washer) in the magnetic circuit structure of the sound-generating device. That is, the magnetic plate assembly 100 can be an assembly composed of the magnetic yoke and its surface plating layer 102, or an assembly composed of the magnetic plate and its surface plating layer 102, or both. Therefore, the magnetic plate assembly 100 in this embodiment of the invention is not limited to a single component at a specific location, but generally refers to a magnetically conductive component with the features of the aforementioned plating layer 102 of this invention on its surface. In this embodiment of the invention, the magnetic plate assembly 100 can function as a magnetic yoke, a magnetic plate, or both, depending on the specific design requirements.

[0040] Optionally, the coating 102 includes a main body and reinforcing nanoparticles 103 distributed within the main body. The main body is composed of a polycrystalline material and contains at least one element selected from iron, cobalt, and nickel.

[0041] In this embodiment, the main body of the coating 102 is made of a polycrystalline soft magnetic metal material, which gives the coating 102 good magnetic permeability and can effectively maintain or even optimize the magnetic flux efficiency of the magnetic plate assembly 100, thereby maintaining or even optimizing the acoustic performance of the speaker.

[0042] Optionally, the main body contains at least a first component material and a second component material, wherein the first component material is nickel and the second component material is at least one of iron and cobalt.

[0043] In this embodiment, the main body of the coating 102 contains at least one of the ferromagnetic materials nickel, iron, and cobalt. Iron, cobalt, and nickel atoms possess a large number of unpaired electrons in their 3d electron shells, which endow each ferromagnetic atom with a strong "atomic magnetic moment." When the electron clouds of adjacent atoms overlap, a strong interaction force is generated between the atoms. This exchange force tends to keep the spin directions of the unpaired electrons of adjacent atoms parallel. Due to this strong exchange effect, within a small region, the magnetic moments of all atoms spontaneously align neatly, forming a magnetic domain. Under the influence of an external magnetic field, all magnetic domains become uniform, thus exhibiting strong macroscopic magnetism. Through this ferromagnetic mechanism, the coating 102 itself can become an effective component of the magnetic circuit, rather than a magnetoresistance barrier. Furthermore, the first constituent material, nickel, has good corrosion resistance, and the second constituent materials, iron and cobalt, have similar molar masses and densities to nickel, thus allowing the formation of an infinite solid solution, ensuring the density and compositional uniformity of the coating 102 structure. Adding cobalt to the coating 102 can improve its magnetism, hardness, and corrosion resistance. Adding iron to the coating 102 can improve its magnetism and reduce costs.

[0044] Understandably, in conventional techniques, amorphous materials are typically chosen for coating 102 to achieve higher permeability. While amorphous materials have higher initial permeability, they are prone to accumulating significant internal stress during fabrication. Furthermore, to maintain their amorphous state, amorphous materials usually contain large amounts of metalloid elements such as boron, silicon, and phosphorus, with ferromagnetic elements generally accounting for less than 80%. Consequently, the specific saturation magnetization of amorphous materials is typically low. This means that under conditions of extremely narrow magnetic gaps and extremely high magnetic flux density, such as in miniature loudspeakers, the amorphous coating 102 is highly susceptible to magnetic saturation and failure. Moreover, the significant internal stress under long-term high-frequency vibration can lead to a decrease in the adhesion between the coating 102 and the substrate, or even peeling. In contrast, this embodiment of the invention selects polycrystalline materials to prepare coating 102, allowing for a higher quality of ferromagnetic material in coating 102, for example, a proportion as high as 90-100%. The higher the proportion of ferromagnetic material, the more atomic magnetic moments are contained in coating 102, resulting in stronger interatomic interactions, better magnetic permeability, and higher specific saturation magnetization. Meanwhile, the polycrystalline structure has perfect crystallization and good stability, avoiding the problem of amorphous materials continuously crystallizing as the temperature rises, which would result in poor stability of magnetic permeability.

[0045] Optionally, if the second component material is cobalt, the mass percentage of the second component material in the main body is 3% to 50%. For example, the mass percentage of the second component material in the main body is 3%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, etc.

[0046] In this embodiment, the first component material is nickel, which accounts for more than or equal to 50% of the mass of the coating 102. This allows nickel to spontaneously form an extremely dense and stable passivation film on the surface of the coating 102. This film is very dense and can effectively block the intrusion of oxygen, water molecules, and various corrosive ions, improving the corrosion resistance of the coating 102. However, if the nickel content is too low, the corrosion resistance of the coating 102 deteriorates. When the second component material is cobalt, if the cobalt content is too low, the properties of the coating 102 are close to those of pure nickel, resulting in a low specific saturation magnetization and limited permeability, making it difficult to provide sufficient magnetic permeability under the high magnetic flux density conditions of ultra-thin magnetic circuits. If the cobalt content is too high, the coating 102 will exhibit permanent magnetism, with mutual attraction, making it difficult to uniformly disperse the coating 102 during the preparation process.

[0047] Optionally, if the second component material is iron, the mass percentage of the second component material in the main body is 3% to 40%. For example, the mass percentage of the second component material in the main body is 3%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, etc.

[0048] In this embodiment, when the second component material is iron, although iron atoms have a high atomic magnetic moment, their corrosion resistance is poor. Therefore, when the iron content in the coating 102 is higher than 40%, the corrosion resistance of the coating 102 will decrease rapidly. If the iron content is too low, the properties of the coating 102 are close to those of pure nickel, resulting in a low specific saturation magnetization and limited magnetic permeability, making it difficult to provide sufficient magnetic permeability under the high magnetic flux density conditions of ultra-thin magnetic circuits.

[0049] Optionally, if the second component material is cobalt and iron, the mass percentage of the second component material in the main body is 5% to 50%, wherein the mass percentage of iron is less than or equal to 40%. For example, the mass percentage of the second component material in the main body is 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, etc.; and the mass percentage of iron is less than or equal to 40%, 35%, 30%, 25%, 20%, 15%, 10%, 5%, 3%, etc.

[0050] In this embodiment, both iron and cobalt are elements with high saturation magnetization. Their addition significantly improves the specific saturation magnetization and permeability of the coating 102. Cobalt also improves the density of the oxide film, increases hardness, and enhances corrosion resistance, thus giving the coating 102 excellent overall performance. If the content of the second component is too low, the properties of the coating 102 will be close to pure nickel, resulting in a low specific saturation magnetization and limited permeability, making it difficult to provide sufficient magnetic permeability under the high flux density conditions of ultra-thin magnetic circuits. If the content of the second component is too high, the two elements will be difficult to disperse uniformly in the coating 102, leading to insufficient stability of the coating 102. Furthermore, this embodiment of the invention limits the mass percentage of iron to less than or equal to 40%. This is because although iron has extremely high specific saturation magnetization and low cost, its electrodeposition internal stress is high and its corrosion resistance is poor. If the iron content is too high, the corrosion resistance of the coating 102 will significantly decrease.

[0051] Optionally, the mass percentage of reinforcing nanoparticles 103 in the coating 102 is 0.1% to 20%. For example, the mass percentage of reinforcing nanoparticles 103 in the coating 102 is 0.1%, 0.5%, 1%, 3%, 5%, 7%, 9%, 10%, 13%, 15%, 17%, 19%, 20%, etc.

[0052] In this embodiment, if the amount of reinforcing nanoparticles 103 added to the coating 102 is too small, the density of the particles in the coating will be insufficient, resulting in a limited strengthening effect on the main body and making it difficult to fully realize the expected effect of particle reinforcement. If the amount of reinforcing nanoparticles 103 added is too large, the probability of contact between particles will increase significantly, making agglomeration more likely and forming large particle clusters. These agglomerates will destroy the compositional uniformity and structural density of the coating 102, leading to excessive local internal stress and increased coating brittleness. At the same time, microcracks are easily generated at the interface between the agglomerates and the main body, becoming stress concentration points and corrosion channels, which will reduce the mechanical properties and magnetic permeability of the coating 102. Therefore, in this embodiment of the invention, the mass ratio of reinforcing nanoparticles 103 is controlled within a specific range (0.1~20%), which ensures a sufficient number of particles to achieve a significant dispersion reinforcement effect, while effectively avoiding particle agglomeration and the resulting problems of uneven coating, excessive internal stress, increased brittleness, and decreased magnetic permeability, thereby achieving the best balance between coating strength, toughness, and magnetic permeability.

[0053] Optionally, the maximum size of the reinforcing nanoparticles 103 is less than or equal to 5 μm. For example, the maximum size of the reinforcing nanoparticles 103 is less than or equal to 5 μm, 4.5 μm, 4 μm, 3.5 μm, 3 μm, 2.5 μm, 2 μm, etc.

[0054] In this embodiment, the maximum size of the reinforcing nanoparticles 103 is a crucial factor determining the density, interface integrity, and corrosion resistance of the coating 102. If the reinforcing particles are too large, they are difficult to embed effectively into the substrate during electrodeposition or electroless plating, tending to float on the surface or partially protrude from it. At the interface between the particles and the substrate, due to the difference in their crystal structure and coefficient of thermal expansion, micron-sized gaps or voids are easily formed. These gaps become channels for the penetration of corrosive media (such as chloride ions and water molecules), significantly reducing the corrosion resistance of the coating 102 and causing premature oxidation corrosion of the substrate. Simultaneously, large-sized particles easily form stress concentration points at the interface, becoming crack initiation points when the coating 102 is subjected to external forces or thermal cycling. As the cracks propagate, they eventually lead to the peeling or cracking of the coating 102. Therefore, in this embodiment of the invention, the maximum size of the reinforcing nanoparticles 103 is controlled to be no more than 5 μm, ensuring that the particles can be uniformly and densely embedded inside the main body, forming a good interface bond between the particles and the main body, avoiding gaps and stress concentration, thereby fully leveraging the particle reinforcement effect and maintaining excellent corrosion resistance while ensuring the structural integrity of the coating 102.

[0055] Optionally, the elastic modulus of the reinforcing nanoparticles 103 is 300~1000 GPa. For example, the elastic modulus of the reinforcing nanoparticles 103 is 300 GPa, 400 GPa, 500 GPa, 600 GPa, 700 GPa, 800 GPa, 900 GPa, 1000 GPa, etc.

[0056] In this embodiment, the elastic modulus of the reinforcing nanoparticles 103 is a key parameter determining its strengthening effect and the mechanical integrity of the coating 102. When the modulus of the reinforcing nanoparticles 103 is higher than that of the main body, the particles can effectively bear external loads and hinder the movement of dislocations in the matrix, significantly improving the hardness, yield strength, and wear resistance of the coating 102 through dispersion strengthening and second-phase strengthening mechanisms. However, if the modulus of the reinforcing nanoparticles 103 is too low, the particles themselves lack stiffness and are prone to deformation under external forces, failing to effectively hinder dislocation movement, resulting in an insignificant strengthening effect and making it difficult to achieve the expected strengthening effect of the particles. If the modulus of the reinforcing nanoparticles 103 is too high, the modulus difference between the particles and the main body is too large. During external loads or thermal cycling, severe stress concentration is easily generated at the interface between the particles and the main body, becoming a source of microcrack initiation. As the cracks propagate, they eventually lead to cracking or peeling of the coating 102. In this embodiment of the invention, by setting the elastic modulus of the reinforcing nanoparticles 103 to 300~1000 GPa, it is ensured that the reinforcing nanoparticles 103 have sufficient stiffness to achieve effective dispersion reinforcement and second phase reinforcement, significantly improving the hardness and wear resistance of the coating 102, while avoiding the problems of interface stress concentration and crack initiation caused by excessive modulus difference, thereby achieving the best balance between the strength and toughness of the coating 102.

[0057] Optionally, the hardness of the coating 102 is 200~2000 Hv. For example, the hardness of the coating 102 is 200 Hv, 400 Hv, 600 Hv, 800 Hv, 1000 Hv, 1200 Hv, 1400 Hv, 1600 Hv, 1800 Hv, 2000 Hv, etc.

[0058] In this embodiment, the hardness of the coating 102 is an important mechanical indicator for measuring its resistance to local deformation, scratches, and wear. Higher hardness enables the coating 102 to effectively resist external impacts, surface scratches, and wear during the manufacturing, assembly, and reliability testing of the magnetic plate assembly 100, ensuring the structural integrity and long-term service stability of the coating 102. However, higher hardness is not always better. When the hardness of the coating 102 is too high, its toughness decreases accordingly, and the internal stress increases significantly. The coating 102 is prone to microcracks or even overall cracking when subjected to bending or impact loads. At the same time, excessively high hardness is often accompanied by an increase in residual stress inside the coating 102, reducing the bonding strength between the coating 102 and the body 101, and even causing spontaneous peeling of the coating 102 in extreme cases. In addition, an excessively hard coating 102 cannot deform in tandem with the relatively soft body 101 under stress, and the deformation mismatch at the interface will further exacerbate the risk of cracking. Therefore, in this embodiment of the invention, the hardness of the coating 102 is set to 200~2000 Hv, which ensures that the coating 102 has sufficient scratch resistance and wear resistance to meet the mechanical requirements during manufacturing and service, while avoiding problems such as decreased toughness, excessive internal stress and cracking of the coating 102 caused by excessive hardness, thus achieving synergistic optimization of hardness and toughness.

[0059] Optionally, the coefficient of friction of the coating 102 is 0.1 to 2. For example, the coefficient of friction of the coating 102 is 0.1, 0.2, 0.4, 0.6, 0.8, 1, 1.2, 1.4, 1.6, 1.8, 2, etc.

[0060] Optionally, the coefficient of friction of the coating 102 is 0.1 to 1.

[0061] In this embodiment, if the coefficient of friction of the coating 102 is too high, the surface of the coating 102 is prone to wear, scratches, or even peeling off when it collides with other components or tooling, affecting product yield and long-term reliability. If the coefficient of friction of the coating 102 is too low, although the surface is smooth and has good wear resistance, the magnetic plate assembly 100 and the magnet assembly usually need to be bonded and fixed with adhesive. An excessively low coefficient of friction means that the surface is too smooth and the surface energy is low, making it difficult for the adhesive to spread and wet the surface of the coating 102 evenly, resulting in insufficient bonding strength. In drop or vibration tests, the magnet is prone to separation failure from the magnetic plate assembly 100. However, by setting the coefficient of friction of the coating 102 to 0.1~2, this embodiment of the invention ensures that the surface of the coating 102 has moderate wear resistance and that the adhesive can spread well on the surface of the coating 102, achieving reliable bonding with the magnet assembly.

[0062] In this embodiment, by providing a coating containing reinforcing nanoparticles on the surface of the main body, and ensuring that the main body of the coating contains at least one ferromagnetic element selected from iron, cobalt, and nickel, the coating possesses excellent magnetic permeability, effectively maintaining or even optimizing the magnetic flux efficiency of the magnetic plate assembly, thereby maintaining or even optimizing the acoustic performance of the speaker. By controlling the mass percentage of the reinforcing nanoparticles to 0.1~20%, limiting the maximum size to below 5 μm, and setting the elastic modulus to 300~1000 GPa, the reinforcing nanoparticles can be uniformly distributed in the polycrystalline main body without agglomeration, while exhibiting significant dispersion strengthening and second-phase strengthening effects. This allows the coating to effectively hinder dislocation movement, thereby significantly improving mechanical properties while maintaining the high magnetic permeability of the substrate. The hardness of the coating is increased to 200~2000 Hv, giving the magnetic plate assembly excellent resistance to deformation and scratches, and effectively reducing surface lattice distortion during manufacturing and testing. Furthermore, the coefficient of friction of the coating is controlled between 0.1 and 2, giving the surface of the magnetic plate assembly appropriate wear resistance. This allows it to resist wear and scratches during handling without being too smooth, which could affect the spread and bonding reliability of the adhesive between it and other components in the magnetic circuit structure (e.g., magnet components). In this embodiment of the invention, the above technical solution enables the magnetic plate assembly to achieve ultra-thinness and lightweight while possessing excellent mechanical stability and magnetic permeability.

[0063] In one feasible embodiment, the reinforcing nanoparticles 103 include at least one of graphene, carbon nanotubes, boron nitride, boron carbide, and aluminum nitride.

[0064] Alternatively, graphene is a material composed of carbon atoms arranged in sp... 2 Two-dimensional nanomaterials with hybrid orbitals forming a hexagonal honeycomb lattice. As reinforcing nanoparticles 103, graphene possesses extremely high elastic modulus and tensile strength, while also exhibiting excellent electrical and thermal conductivity. Introducing it into coating 102 provides crystallization nuclei for metal particles during the deposition process, refining the grain size and improving the uniformity of coating 102. Furthermore, the physical barrier effect of the two-dimensional sheets effectively hinders dislocation movement and crack propagation, significantly improving the hardness, wear resistance, and corrosion resistance of coating 102.

[0065] Optionally, carbon nanotubes are hollow tubular one-dimensional nanomaterials formed by rolling up graphene sheets, similar to a fibrous phase, and have an extremely high aspect ratio. As reinforcing nanoparticles 103, when carbon nanotubes are tightly bonded to the main body of the coating 102, they can withstand more loads, hinder dislocation movement, prevent crack propagation, and improve the hardness and wear resistance of the coating 102.

[0066] Optionally, boron nitride is a compound composed of boron and nitrogen atoms, with a hexagonal crystal form (h-BN) exhibiting a layered structure similar to graphene. As reinforcing nanoparticles 103, boron nitride possesses self-lubricating properties; its addition to coating 102 can both improve hardness through dispersion strengthening and reduce the coefficient of friction. Simultaneously, the chemical inertness of boron nitride enables it to effectively block corrosive media, enhancing the high-temperature oxidation resistance and corrosion resistance of coating 102.

[0067] Optionally, boron carbide is an ultrahard ceramic material composed of boron and carbon. As reinforcing nanoparticles 103, boron carbide possesses extremely high elastic modulus, low density, and excellent neutron absorption capacity. Introducing it into the coating 102 can significantly improve the hardness, wear resistance, and scratch resistance of the coating 102 through dispersion strengthening and second-phase strengthening mechanisms.

[0068] Optionally, aluminum nitride is a hexagonal ceramic material composed of aluminum and nitrogen atoms, possessing high elastic modulus, excellent thermal conductivity, and good electrical insulation. As reinforcing nanoparticles 103, aluminum nitride can improve the hardness and wear resistance of the coating 102 through dispersion strengthening.

[0069] In one feasible embodiment, graphene includes at least one of intrinsic graphene, graphene oxide, reduced graphene oxide, and surface-modified graphene.

[0070] In this embodiment, intrinsic graphene possesses a perfect crystal structure and excellent mechanical, electrical, and thermal properties, maximizing its reinforcing effect. Graphene oxide contains numerous oxygen-containing functional groups (such as hydroxyl, carboxyl, and epoxy groups) on its surface, giving it good dispersibility and complexation ability with metal ions in aqueous plating solutions, facilitating uniform co-deposition in coating 102 via electroplating or electroless plating processes. Reduced graphene oxide is a product that partially restores the graphene structure based on graphene oxide, possessing both good dispersibility and high mechanical properties. Surface-modified graphene introduces specific functional groups through chemical grafting or physical adsorption, allowing for customized design based on the plating solution system and process requirements, further improving interfacial compatibility and bonding strength with the coating 102 substrate. In this embodiment, by selecting or combining the above-mentioned graphene types, an optimal balance can be achieved between dispersibility, interfacial bonding strength, and mechanical reinforcement effect, depending on the specific plating solution system, process conditions, and performance requirements.

[0071] In one feasible embodiment, the thickness of the graphene is less than or equal to 100 nm. For example, the thickness of the graphene is less than or equal to 100 nm, 80 nm, 50 nm, 30 nm, 20 nm, 10 nm, etc.

[0072] In this embodiment, a smaller graphene thickness means fewer layers, a larger specific surface area, and a correspondingly increased contact area with the host material. This facilitates a tighter interfacial bond between the graphene and the host material, thereby more effectively transferring the load from the host material to the graphene and achieving efficient dispersion reinforcement. Simultaneously, thin-layer graphene exhibits better flexibility and bending compliance, enabling it to be uniformly dispersed in the coating and form a three-dimensional network structure without easily folding or agglomerating. Furthermore, as heterogeneous nucleation sites, thin-layer graphene can effectively refine the grain size of the host material, further improving the hardness and strength of the coating. Therefore, by controlling the graphene thickness to within 100 nm, this embodiment of the invention ensures a high specific surface area, good dispersibility, and significant grain refinement effect in the coating.

[0073] In one feasible embodiment, the ratio of the graphene sheet diameter to its thickness (i.e., the aspect ratio) is greater than or equal to 100. For example, the ratio of the graphene sheet diameter to its thickness is greater than or equal to 100, 200, 250, 310, 350, 400, etc.

[0074] In this embodiment, the aspect ratio of the graphene is controlled to be no less than 100, meaning the graphene sheets have a large lateral dimension and a very small thickness. The high aspect ratio of the graphene allows it to be laid flat or overlapped in the coating 102, forming a reinforcing network similar to a "brick-and-mortar" structure. When the coating 102 is subjected to external force, the large-sized graphene sheets can bear more load. Simultaneously, when dislocations encounter graphene sheets during their movement, they cannot easily cut through or bypass them, requiring additional energy to overcome the obstacle, thus significantly improving the hardness and strength of the coating 102. Furthermore, the high aspect ratio of the graphene allows it to form complex, tortuous paths in the coating 102, extending the penetration distance of corrosive media (such as chloride ions and water molecules) and enhancing the corrosion resistance of the coating 102.

[0075] In one feasible embodiment, the tensile strength of graphene is 1~150 GPa. For example, the tensile strength of graphene is 1 GPa, 5 GPa, 10 GPa, 20 GPa, 40 GPa, 60 GPa, 80 GPa, 90 GPa, 100 GPa, 120 GPa, 140 GPa, 150 GPa, etc.

[0076] In this embodiment, different types of graphene have different tensile strengths. Intrinsic graphene, with its perfect lattice structure, has a tensile strength exceeding 130 GPa, exhibiting the most significant reinforcing effect. Graphene oxide, due to the presence of numerous defects and oxygen-containing functional groups on its surface, has a relatively lower tensile strength, but still possesses some reinforcing capability. If the tensile strength of graphene is below 1 GPa, its inherent strength is insufficient, making it prone to fracture under external forces. It cannot effectively bear loads or hinder dislocation movement, resulting in negligible improvement in the hardness and strength of the coating 102. If the tensile strength is too high, although the reinforcing effect is excellent, the preparation of high-quality, large-size intrinsic graphene is difficult and costly, hindering industrial-scale mass application. This embodiment of the invention controls the tensile strength of graphene within the range of 1~150 GPa, ensuring that graphene has sufficiently high intrinsic strength to effectively reinforce the coating 102, while allowing flexible selection among intrinsic graphene, graphene oxide, or reduced graphene oxide based on actual cost and process requirements.

[0077] In one feasible embodiment, the carbon nanotubes include at least one of single-walled carbon nanotubes, multi-walled carbon nanotubes, and surface-modified carbon nanotubes.

[0078] In this embodiment, single-walled carbon nanotubes are formed by rolling up a single layer of graphene, resulting in fewer structural defects, a large aspect ratio, and excellent mechanical properties, achieving significant reinforcement effects with minimal addition. Multi-walled carbon nanotubes consist of multiple concentric walls, have a larger diameter, relatively lower preparation costs, and their multi-wall structure provides higher structural stability in coating 102. Surface-modified carbon nanotubes introduce specific functional groups (such as carboxyl, amino, and hydroxyl groups) through chemical grafting or physical adsorption, significantly improving the dispersibility of carbon nanotubes in aqueous plating solutions and the interfacial bonding strength with the nickel matrix. In this embodiment, by selecting or combining the above-mentioned types of carbon nanotubes, an optimal balance can be achieved between dispersibility, interfacial bonding strength, and mechanical reinforcement effects, depending on the specific plating solution system, process conditions, and performance requirements.

[0079] In one feasible embodiment, the outer diameter of the carbon nanotube is less than or equal to 50 nm. For example, the outer diameter of the carbon nanotube is less than or equal to 50 nm, 45 nm, 40 nm, 35 nm, 30 nm, 20 nm, etc.

[0080] In this embodiment, the outer diameter of the carbon nanotube is a key parameter determining its specific surface area, structural integrity, and reinforcing effect. A smaller outer diameter results in a higher specific surface area and a larger contact area between the carbon nanotube and the coating 102 substrate per unit mass. This allows for a tighter and more complete interfacial bond with the host, thereby more effectively transferring the load from the host to the carbon nanotube, achieving efficient load transfer and dispersion strengthening. Conversely, if the outer diameter of the carbon nanotube is too large, it means there are many tube wall layers. These layers are only bonded by weak van der Waals forces, making them prone to relative slippage under external loads, significantly reducing the effective load-bearing capacity of the carbon nanotube itself. Therefore, the outer diameter of the carbon nanotube is controlled to be within 50 nm.

[0081] In one feasible embodiment, the length-to-outer diameter ratio (i.e., aspect ratio) of the carbon nanotube is greater than or equal to 200. For example, the length-to-outer diameter ratio of the carbon nanotube is greater than or equal to 200, 250, 300, 350, etc.

[0082] In this embodiment, high aspect ratio carbon nanotubes can intertwine and overlap in the coating 102 to form a three-dimensional network structure. This network structure can effectively prevent crack initiation and propagation. When the coating 102 is subjected to external force, cracks encountering the carbon nanotube network need to be deflected, branched, or bypassed, thereby consuming a large amount of fracture energy and significantly improving the fracture toughness and fatigue resistance of the coating 102. Simultaneously, the high aspect ratio carbon nanotubes, as heterogeneous nucleation sites, can provide more nucleation sites, effectively refining the grain size of the coating 102, and further improving the hardness and strength of the coating 102. If the aspect ratio is too small, it is difficult to form an effective three-dimensional network structure, and the reinforcing effect is significantly reduced. Therefore, in this embodiment of the invention, the aspect ratio of the carbon nanotubes is controlled to be above 200.

[0083] In one feasible embodiment, the tensile strength of the carbon nanotubes is 40~200 GPa. For example, the tensile strength of the carbon nanotubes is 40 GPa, 60 GPa, 80 GPa, 100 GPa, 120 GPa, 140 GPa, 160 GPa, 180 GPa, 200 GPa, etc.

[0084] In this embodiment, the tensile strength of different types of carbon nanotubes varies. Single-walled carbon nanotubes, with their perfect structure and minimal defects, achieve a tensile strength of 100-200 GPa, exhibiting the most significant reinforcing effect. Multi-walled carbon nanotubes, composed of multiple concentric walls, exhibit relative slippage between the walls and numerous defects, resulting in lower tensile strength compared to single-walled carbon nanotubes. If the tensile strength of the carbon nanotube is below 40 GPa, its inherent strength is insufficient to effectively bear the load, making it prone to fracture under external forces. It cannot effectively hinder dislocation movement and load transfer, thus limiting its contribution to improving the hardness and strength of the 102 coating. Conversely, excessively high tensile strength, while providing excellent reinforcing effects, results in high production costs for high-quality single-walled carbon nanotubes, hindering industrial-scale application. Therefore, this embodiment of the invention controls the tensile strength of the carbon nanotubes within the range of 40-200 GPa.

[0085] In one feasible embodiment, the specific surface area of ​​the reinforcing nanoparticles 103 is 100~3000 m². 2 / g; for example, the specific surface area of ​​the enhanced nanoparticles 103 is 100 m². 2 / g、200 m 2 / g、400 m 2 / g、600 m 2 / g、800 m 2 / g, 1000 m 2 / g, 1500 m 2 / g、2000 m 2 / g、2500 m 2 / g、3000 m 2 / g etc.

[0086] In this embodiment, a higher specific surface area means a larger surface area per unit mass of particles. This increases the contact area between the reinforcing nanoparticles 103 and the main body of the coating 102, which is beneficial for the mechanical bonding and chemical adhesion between the reinforcing particles and the main body, thereby improving the overall adhesion and anti-peeling ability of the coating 102. However, an excessively high specific surface area leads to a sharp increase in particle surface energy, significantly enhancing the tendency for spontaneous aggregation of particles due to van der Waals forces. This results in particles being difficult to disperse uniformly in the plating solution and easily forming agglomerates. Agglomerated particles cannot exert the reinforcing effect of individual nanoparticles; instead, uneven distribution causes localized performance degradation of the coating 102. This embodiment of the invention controls the specific surface area of ​​the reinforcing nanoparticles 103 to be between 100 and 3000 m². 2 Within the range of / g, it ensures that there is a sufficiently large contact area between the particles and the main body to achieve good interfacial bonding, while avoiding the problems of particle agglomeration and uneven dispersion caused by excessive specific surface area.

[0087] In one feasible embodiment, the reinforcing nanoparticles 103 include at least one of sheet-like and tubular shapes.

[0088] In this embodiment, the sheet-like or tubular reinforcing nanoparticles 103 can overlap or interweave better in the coating 102, forming an effective reinforcing network. Furthermore, the sheet-like structure can spread on the surface during friction, forming a lubricating film and reducing the coefficient of friction.

[0089] In one feasible embodiment, the average thickness of the coating 102 is less than or equal to 20% of the average thickness of the body portion 101; for example, the average thickness of the coating 102 is less than or equal to 20%, 18%, 16%, 15%, 14%, 12%, 10%, 8%, 6%, 5%, etc. of the average thickness of the body portion 101.

[0090] In one feasible embodiment, the average thickness of the coating 102 is 1 to 50 μm; for example, the average thickness of the coating 102 is 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, etc.

[0091] Optionally, the average thickness of the coating 102 is 3~30 μm.

[0092] In this embodiment, the thicker the coating 102, the better its corrosion resistance. However, if the coating 102 is too thick, the overall thickness of the magnetic circuit structure increases, the magnetic lines of force travel longer, and the magnetic permeability deteriorates. Furthermore, if the overall thickness is too large, the vibration space of the diaphragm decreases, affecting the amplitude of the speaker. Moreover, the coating 102 contains significant internal stress. When the body portion 101 is too thin, it is difficult for the body portion 101 to resist the deformation caused by the internal stress of the coating 102, resulting in bending deformation. This causes microcracks in the hard coating 102, reduces the corrosion resistance of the coating 102, and may even lead to the coating 102 peeling off. Therefore, in this embodiment of the invention, the average thickness of the coating 102 is determined to be less than or equal to 20% of the thickness of the body portion 101; the average thickness of the coating 102 is 1~50 μm.

[0093] In one feasible embodiment, the saturation magnetization of the coating 102 is 10~2000 emu / cm. 3 For example, the saturation magnetization of coating 102 is 10 emu / cm. 3 50 emu / cm 3 100 emu / cm 3 200 emu / cm 3 400 emu / cm 3 500 emu / cm 3600 emu / cm 3 800 emu / cm 3 1000 emu / cm 3 1200 emu / cm 3 1400 emu / cm 3 1600 emu / cm 3 1800 emu / cm 3 2000 emu / cm 3 wait.

[0094] Optionally, the saturation magnetization of the coating 102 is 40~1500 emu / cm. 3 .

[0095] Optionally, saturation magnetization refers to the magnetization intensity of a material when it is magnetized to its maximum extent in an applied magnetic field, i.e., when all magnetic moments are aligned in the same direction. Saturation magnetization can be obtained by measuring a vibrating sample magnetometer.

[0096] In this embodiment, the addition of non-magnetic reinforcing nanoparticles 103 reduces the magnetic permeability of the coating 102. Therefore, when the saturation magnetization of the coating 102 is below 10 emu / cm 3 When the saturation magnetization is greater than 2000 emu / cm, it indicates insufficient magnetic permeability. 3 At the same time, the coating 102 is required to contain a large amount of iron, cobalt, nickel, ferromagnetic and other elements, which makes the proportion of reinforcing nanoparticles 103 insufficient, and the coating 102 has low hardness and poor wear resistance and scratch resistance.

[0097] In one feasible embodiment, the enhanced nanoparticles 103 are modified with a surfactant, which includes at least one of cationic surfactants, anionic surfactants, nonionic surfactants, and compound surfactants.

[0098] Optionally, the anionic surfactant includes sodium dodecyl sulfate (SDS) and / or sodium dodecyl sulfonate (SDBS). After the anionic surfactant dissolves in water, its hydrophobic end can be adsorbed onto the surface of the reinforced nanoparticles 103, with the hydrophilic anionic head facing the solution. This further enhances the electronegativity of the particle surface, preventing particle aggregation. During the electroplating process to prepare the coating 102, the reinforced nanoparticles 103 near the cathode are encapsulated by the growing coating 102 body under hydrogen evolution and stirring, while the anionic surfactant keeps the reinforced nanoparticles 103 stable as monodisperse nanoparticles near the cathode.

[0099] Optionally, the cationic surfactant includes cetyltrimethylammonium bromide (CTAB) and / or cetyltrimethylammonium chloride (CTAC). After dissolving in water, the cationic surfactant forms positively charged hydrophilic groups, which adsorb onto the surface of the reinforcing nanoparticles 103, altering the surface charge of the reinforcing nanoparticles 103 to make them positively charged. Under the influence of an electric field, the positively charged particles migrate towards the cathode along with the metal cations and are deposited together with the metal ions in the coating 102.

[0100] Optionally, the nonionic surfactant includes alkylphenol polyoxyethylene ether, which can be adsorbed on the surface of the enhanced nanoparticles 103 and form a steric hindrance effect to avoid particle agglomeration. In addition, it can reduce the surface tension of the plating solution, improve the wettability of the plating solution to the body 101, and facilitate the deposition of the coating 102.

[0101] In this embodiment, the reinforced nanoparticles 103 have a large specific surface area and are prone to agglomeration. Therefore, this embodiment of the invention uses a surfactant to make them uniformly dispersed in the plating solution, which can also improve the bonding force between the reinforced nanoparticles 103 and the main body and improve the stability of the plating layer 102.

[0102] This invention also provides a sound-generating device, which includes a housing and a magnetic circuit structure disposed on the housing. The magnetic circuit structure includes a magnet assembly and a magnetic guide plate assembly as described above. The magnetic guide plate assembly includes at least one of a magnetic guide yoke and a magnetic guide plate disposed at the end of the magnet assembly away from the magnetic guide yoke.

[0103] Optionally, refer to Figure 2 The sound-generating device 200 includes a housing 201 and a magnetic circuit structure disposed on the housing 201. The magnetic circuit structure may include a central magnetic part and a side magnetic part, wherein the central magnetic part and the side magnetic part are spaced apart to form a magnetic gap 202. The sound-generating device 200 also includes a diaphragm assembly 203 and a voice coil 204. One end of the voice coil 204 is connected to the diaphragm assembly 203, and the other end of the voice coil 204 is inserted into the magnetic gap 202, so that when energized, it is driven by the magnetic field to vibrate and generate sound. The central magnetic part includes a central magnet 205a and a central magnetic guide plate 101a, and the side magnetic part includes a side magnet 205b and a side magnetic guide plate 101b. The central magnet 205a and the side magnet 205b together form a magnet assembly to provide magnetic flux to the magnetic circuit. One end of the central magnet 205a is connected to the magnetic yoke 101c, and the other end is connected to the central magnetic plate 101a; one end of the side magnet 205b is connected to the magnetic yoke 101c, and the other end is connected to the side magnetic plate 101b. With this arrangement, the magnetic flux forms a closed loop via the magnetic yoke 101c, the central magnet 205a, the central magnetic plate 101a, the magnetic gap 202, the side magnetic plate 101b, and the side magnet 205b, resulting in a high-intensity magnetic field within the magnetic gap 202, thereby enhancing the driving force of the voice coil 204 and the sensitivity of the sound-generating device 200.

[0104] Optionally, refer to Figure 2 The surfaces of the central magnetic plate 101a, the side magnetic plate 101b, and the magnetic yoke 101c are provided with the coating 102 as described above, thereby achieving synergistic optimization of magnetic conductivity and mechanical properties.

[0105] Compared with conventional technology, the beneficial effects of the sound-generating device provided in the embodiments of the present invention are the same as those of the magnetic plate assembly provided in the above embodiments, and other technical features in the sound-generating device are the same as those disclosed in the methods of the above embodiments, and will not be repeated here.

[0106] This invention also provides an electronic device, including the magnetic plate assembly or sound-generating device described above.

[0107] In this embodiment, electronic devices include mobile phones, laptops, tablets, VR (Virtual Reality) devices, AR (Augmented Reality) devices, TWS (True Wireless Stereo) earphones, smart speakers, smart wearable devices, etc.

[0108] Compared with conventional technology, the beneficial effects of the electronic device provided in the embodiments of the present invention are the same as those of the magnetic conductive plate assembly provided in the above embodiments, and other technical features of the electronic device are the same as those disclosed in the methods of the above embodiments, and will not be repeated here.

[0109] To ensure that the details and operations of the above embodiments of the present invention can be clearly understood by those skilled in the art, and to demonstrate the significant advancements in the performance of the embodiments of the present invention, the following examples illustrate the above technical solutions. It should be noted that the following descriptions are merely exemplary and not intended to limit the specific scope of the present invention.

[0110] Example 1 An electroplating solution is provided, comprising: 250 g / L nickel sulfate, 35 g / L boric acid, and 50 g / L nickel chloride. 3 g / L of hexadecyltrimethylammonium bromide (a cationic surfactant)-modified sheet graphene is added to the electroplating solution and dispersed by ultrasonic vibration and stirring. The graphene has a specific surface area of ​​2380 m². 2 / g, thickness 4~20 nm, aspect ratio 250~500, tensile strength 70~100 GPa.

[0111] The substrate, SPCC (0.3 mm thick), undergoes pre-plating treatment, including alkaline degreasing, acid washing, hot water washing, and drying. Based on the above electroplating solution, a nickel-graphene coating (graphene mass percentage of 1%) is electroplated onto the surface of the pre-plating substrate to obtain the tray frame, wherein the current density is 5 A / dm³. 2 Temperature 40 ℃, electroplating time 20 min, pH value 4.

[0112] Example 2 An electroplating solution is provided, comprising: nickel sulfamate 300 g / L, cobalt sulfamate 30 g / L, and boric acid 35 g / L. Sodium dodecyl sulfate (anionic surfactant) modified carbon nanotubes (6 g / L) are added to the electroplating solution and dispersed by ultrasonic vibration and stirring. The carbon nanotubes have an outer diameter of 8–15 nm, an aspect ratio of 200–800, and a tensile strength >90 GPa.

[0113] The substrate, SPCC (0.3 mm thick), undergoes pre-plating treatment, including alkaline cleaning and degreasing, acid cleaning, hot water cleaning, and drying. Based on the above electroplating solution, a nickel-cobalt-carbon nanotube coating (carbon nanotubes accounting for 2% by mass and cobalt accounting for 15% by mass) is electroplated onto the surface of the pre-plating substrate to obtain the tray frame, wherein the current density is 3 A / dm³. 2 Temperature 50 ℃, electroplating time 20 min, pH value 4.

[0114] Comparative Example 1 An electroplating solution is provided, wherein the components of the electroplating solution include: nickel sulfamate 300 g / L, cobalt sulfamate 30 g / L, and boric acid 35 g / L.

[0115] The substrate, SPCC (0.3 mm thick), undergoes pre-plating treatment, including alkaline degreasing, acid pickling, hot water washing, and drying. Based on the above electroplating solution, a nickel plating layer is electroplated onto the surface of the pre-plating substrate to obtain the tray frame, wherein the current density is 5 A / dm³. 2 Temperature 40 ℃, electroplating time 20 min, pH value 4.

[0116] Comparative Example 2 An electroplating solution is provided, wherein the components of the electroplating solution include: 250 g / L nickel sulfate, 35 g / L boric acid and 50 g / L nickel chloride.

[0117] The substrate, SPCC (0.3 mm thick), undergoes pre-plating treatment, including alkaline cleaning and degreasing, acid cleaning, hot water washing, and drying. Based on the above electroplating solution, a nickel-cobalt plating layer (cobalt content 15% by mass) is electroplated onto the surface of the pre-plating substrate to obtain the tray frame, wherein the current density is 3 A / dm³. 2Temperature 50 ℃, electroplating time 20 min, pH value 4.

[0118] The basin stands of Examples 1-2 and Comparative Examples 1-2 were tested, and the results are shown in Table 1 below: Table 1

[0119] Based on the test results above, it can be seen that the addition of graphene and carbon nanotubes in Examples 1 and 2 refined the coating grains and hindered dislocation movement, thus resulting in higher hardness and better wear resistance in Examples 1 and 2. Simultaneously, the addition of graphene and carbon nanotubes also promoted uniform crystallization, reduced porosity in the coating, and made the coating denser. Therefore, magnetic field lines traveled more freely in the coating, and the saturation magnetization was improved to a certain extent.

[0120] Furthermore, the baskets of Example 2 and Comparative Example 2 were assembled into speakers and subjected to drop tests. After the drop test, the deformation of the basket of Comparative Example 2 was 0.1 mm, while the deformation of the basket of Example 2 was only 0.02 mm. It can be seen that the mechanical properties of the magnetic plate assembly were improved by adding enhanced nanoparticles, and the deformation was significantly reduced.

[0121] In summary, the magnetic plate assembly provided by the embodiments of the present invention can achieve ultra-thinness and lightweight while possessing excellent mechanical stability and magnetic permeability.

[0122] The above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the patent protection scope of the present invention.

Claims

1. A magnetic conductive plate assembly, characterized in that, The magnetic conductive plate assembly includes: a body portion and a coating disposed on the surface of the body portion. The coating includes the main body portion and reinforcing nanoparticles distributed within the main body portion. The main body portion is composed of a polycrystalline material and contains at least a first component material and a second component material. The first component material is nickel, and the second component material is at least one of iron and cobalt. The mass percentage of the reinforcing nanoparticles in the coating is 0.1% to 20%, the maximum size of the reinforcing nanoparticles is less than or equal to 5 μm, the elastic modulus of the reinforcing nanoparticles is 300 to 1000 GPa, the hardness of the coating is 200 to 2000 Hv, and the coefficient of friction of the coating is 0.1 to 2.

2. The magnetic conductive plate assembly as described in claim 1, characterized in that, The enhanced nanoparticles include at least one of graphene, carbon nanotubes, boron nitride, boron carbide, and aluminum nitride.

3. The magnetic conductive plate assembly as described in claim 2, characterized in that, The graphene includes at least one of intrinsic graphene, graphene oxide, reduced graphene oxide, and surface-modified graphene. And / or, the thickness of the graphene is less than or equal to 100 nm; And / or, the ratio of the graphene sheet diameter to its thickness is greater than or equal to 100; And / or, the tensile strength of the graphene is 1~150 GPa.

4. The magnetic conductive plate assembly as described in claim 2, characterized in that, The carbon nanotubes include at least one of single-walled carbon nanotubes, multi-walled carbon nanotubes, and surface-modified carbon nanotubes. And / or, the outer diameter of the carbon nanotube is less than or equal to 50 nm; And / or, the ratio of the length to the outer diameter of the carbon nanotube is greater than or equal to 200; And / or, the tensile strength of the carbon nanotubes is 40~200 GPa.

5. The magnetic plate assembly as described in any one of claims 1 to 4, characterized in that, The specific surface area of the reinforcing nanoparticles is 100-3000 m 2 / g; And / or, the enhanced nanoparticles include at least one of sheet-like and tubular shapes.

6. The magnetic plate assembly as described in any one of claims 1 to 4, characterized in that, The enhanced nanoparticles are modified with surfactants, which include at least one of cationic surfactants, anionic surfactants, nonionic surfactants, and compound surfactants.

7. The magnetic plate assembly as claimed in claim 1, characterized in that, The average thickness of the coating is less than or equal to 20% of the average thickness of the body portion; And / or, the average thickness of the coating is 1~50 μm.

8. The magnetic plate assembly as claimed in claim 1, characterized in that, The saturation magnetization of the coating is 10~2000 emu / cm3.

9. A sound-generating device, characterized in that, The sound-generating device includes a housing and a magnetic circuit structure disposed on the housing. The magnetic circuit structure includes a magnet assembly and a magnetic guide plate assembly as described in any one of claims 1 to 8. The magnetic guide plate assembly includes at least one of a magnetic guide yoke and a magnetic guide plate disposed at one end of the magnet assembly away from the magnetic guide yoke.

10. An electronic device, characterized in that, The electronic device includes a magnetic plate assembly as described in any one of claims 1 to 8, or a sound-generating device as described in claim 9.

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