Permanent magnet

Abstract

According to an embodiment, disclosed is a permanent magnet comprising: a base magnet comprising a-b-c, wherein a includes a rare earth element, b includes a transition element, and c includes boron (B); a barrier layer disposed on the base magnet; and a coating layer disposed on the barrier layer, wherein the barrier layer comprises an amorphous material.

Description

permanent magnet

[0001] The example relates to a permanent magnet.

[0002] Recently, Nd-Fe-B-based permanent magnets are being used in motors such as automotive motors and elevator motors. Depending on their application, these permanent magnets may be exposed to high temperatures or humid environments, particularly moisture containing salt. Therefore, there is a demand for permanent magnets that possess high corrosion resistance while being able to be manufactured at a low cost.

[0003] Furthermore, these permanent magnets have been developed and used for a long time and are widely used in various fields such as electronic information, the automotive industry, medical devices, energy, transportation, mobile devices, and robots. In particular, in line with the recent trend toward lightweight and miniaturization, they are being used in products such as machine tools, electronic information devices, home appliances, mobile phones, robot motors, wind turbines, robots, small motors for automobiles, and drive motors.

[0004] The magnetic properties of such rare-earth permanent magnets can be expressed in terms of residual magnetic flux density (Br) and coercivity (HcJ). In this case, the residual magnetic flux density can be determined by the columnar fraction, density, and magnetic orientation of the rare-earth permanent magnet, while the coercivity is related to the microstructure of the rare-earth permanent magnet.

[0005] However, while NdFeB magnets possess the strongest performance among currently known permanent magnets, they have the disadvantage that their magnetic strength drops sharply as the temperature increases, and above a certain temperature, high-temperature demagnetization occurs, leading to a loss of magnetic performance.

[0006] To address this, high-temperature performance is secured by adding or diffusing heavy rare earth elements such as Dy and Tb into grain boundaries; however, the high cost of Dy and Tb raises the material costs of permanent magnets.

[0007] In addition, to prevent surface oxidation of permanent magnets and ensure reliability, a metal layer (e.g., Ni-Cu-Ni) of 5 to 30 μm is plated on the surface of the permanent magnet to suppress problems such as oxidation. However, since the metal plating layer does not possess magnetic force, there is a problem in that the performance of the magnet decreases by the plating thickness.

[0008] Therefore, there is a need for a permanent magnet structure that solves these problems.

[0009] The embodiment provides a permanent magnet having excellent corrosion resistance, heat resistance, oxidation prevention, and improved magnetic properties by positioning a coating layer, rather than a metal layer without magnetic force, on a base magnet.

[0010] In addition, the embodiment can provide a permanent magnet that improves both magnetic properties and reliability while preventing magnetic degradation in high-temperature environments with a low temperature demagnetization rate by placing an amorphous barrier layer between the coating layer and the base magnet so that the low temperature demagnetization rate characteristics of the coating layer are not degraded on the surface of the base magnet as crystal propagation occurs on one side of the component that contacts the coating layer on the base magnet.

[0011] The problems intended to be solved in the embodiments are not limited thereto, and may also include objectives or effects that can be identified from the means of solving the problems or the embodiments described below.

[0012] A permanent magnet according to an embodiment comprises a base magnet comprising abc (where a comprises a rare earth element, b comprises a transition element, and c comprises boron (B)); a barrier layer disposed on the base magnet; and a coating layer disposed on the barrier layer; wherein the barrier layer comprises an amorphous material.

[0013] The above a may be neodymium (Nd), and the above b may be iron (Fe).

[0014] The thickness of the base magnet may be greater than the thickness of the coating layer or the thickness of the barrier layer.

[0015] The thickness of the coating layer may be greater than the thickness of the barrier layer.

[0016] The above coating layer is SmCo5 or Sm2Co 17 It may include.

[0017] The coating layer may have a crystal structure different from that of the base magnet.

[0018] The above barrier layer may include an amorphous metal or an insulating resin.

[0019] The barrier layer may be located at the edge of one side of the base magnet.

[0020] On one side of the base magnet, the thickness of the barrier layer at the outer edge may be greater than the thickness of the barrier layer at the central part.

[0021] The above coating layer can come into contact with one side of the base magnet.

[0022] The embodiment implements a permanent magnet having excellent corrosion resistance, heat resistance, oxidation prevention, and improved magnetic properties by positioning a coating layer, rather than a metal layer without magnetic force, on a base magnet.

[0023] In addition, the embodiment allows for the realization of a permanent magnet with improved magnetic properties and reliability while preventing magnetic degradation in high-temperature environments with a low temperature demagnetization rate by placing an amorphous barrier layer between the coating layer and the base magnet so that the low temperature demagnetization rate characteristics of the coating layer are not degraded on the surface of the base magnet as crystal propagation occurs on one side of the component that contacts the coating layer on the base magnet.

[0024] The various and beneficial advantages and effects of the present invention are not limited to those described above and may be more easily understood in the process of explaining specific embodiments of the present invention.

[0025] FIG. 1 is a perspective view of a permanent magnet according to an embodiment.

[0026] Figure 2 is a view taken by cutting through Figure 1 at AA'.

[0027] Figure 3 is a view taken by cutting through Figure 1 at BB'.

[0028] Figure 4 is a graph of performance (HcJ, intrinsic coercivity (intrinsic force)) depending on whether a coating layer of the first thickness is formed on the base magnet.

[0029] Figure 5 is a graph of performance (HcJ, intrinsic coercivity (intrinsic force)) depending on whether a second thickness coating layer is formed on the base magnet.

[0030] FIG. 6(a) is a photograph of a permanent magnet after forming a coating layer of a first thickness on a base magnet, and FIG. 6(b) is a photograph of a permanent magnet after forming a coating layer of a second thickness on a base magnet.

[0031] Figure 7 shows the results of X-ray diffraction (XRD) analysis after forming a coating layer on the base magnet.

[0032] Figure 8 is a graph of performance (HcJ, intrinsic coercivity (intrinsic force)) according to heat treatment before and after forming a coating layer on a base magnet.

[0033] FIG. 9 is a flowchart of a manufacturing method for manufacturing a permanent magnet according to an embodiment.

[0034] FIG. 10 is a drawing illustrating a permanent magnet according to another embodiment.

[0035] FIG. 11 is a drawing illustrating a motor with a permanent magnet applied according to an embodiment.

[0036] FIG. 12 is a drawing illustrating an actuator with a permanent magnet applied according to an embodiment.

[0037] The present invention is susceptible to various modifications and may have various embodiments, and specific embodiments are illustrated and described in the drawings. However, this does not specify the present invention.

[0038] It should be understood that the embodiments are not intended to be limited and include all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention.

[0039] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

[0040] However, the technical concept of the present invention is not limited to some of the described embodiments but can be implemented in various different forms, and within the scope of the technical concept of the present invention, one or more of the components among the embodiments may be selectively combined or substituted.

[0041] In addition, terms used in the embodiments of the present invention (including technical and scientific terms) may be interpreted in a sense that is generally understood by those skilled in the art to which the present invention belongs, unless explicitly and specifically defined otherwise. Terms that are commonly used, such as terms defined in advance, may be interpreted in consideration of their meaning in the context of the relevant technology.

[0042] Additionally, the terms used in the embodiments of the present invention are for describing the embodiments and are not intended to limit the present invention. In this specification, the singular form may include the plural form unless specifically stated otherwise in the text, and when described as "at least one of A and B and C (or more than one)," it may include one or more of all combinations that can be combined with A, B, and C.

[0043] Terms including ordinal numbers, such as second, first, etc., may be used to describe various components, but the components are not limited by the terms. The terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the second component may be named the first component, and similarly, the first component may be named the second component. The term "and / or" includes a combination of multiple related described items or any of the multiple related described items. Such terms are intended only to distinguish the component from other components and are not limited by the essence, order, sequence, etc. of the component.

[0044] And, where it is stated that a component is 'connected', 'combined', or 'joined' to another component, this may include not only cases where the component is directly connected, combined, or joined to the other component, but also cases where it is 'connected', 'combined', or 'joined' due to another component located between the component and the other component.

[0045] The terms used in this application are used merely to describe specific embodiments and are not intended to limit the invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, terms such as "comprising" or "having" are intended to specify the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0046] Furthermore, when described as being formed or placed "above or below" each component, "above" or "below" includes not only cases where two components are in direct contact with each other, but also cases where one or more other components are formed or placed between the two components. Additionally, when expressed as "above or below," it may include the meaning of a downward direction as well as an upward direction relative to a single component.

[0047] In addition, the expression that configuration A is positioned between configuration B and configuration C must include the meaning that configuration A is positioned such that at least a portion of it overlaps with configurations B and C in the horizontal and / or vertical directions.

[0048] Expressions referring to directions include horizontal and vertical directions, and the horizontal direction includes a first horizontal direction and a second horizontal direction perpendicular to the first horizontal direction. These are referred to as the first horizontal direction (X-axis), the second horizontal direction (Y-axis), and the vertical direction (Z-axis) according to the Cartesian coordinate system, and the meaning of being superimposed along the horizontal direction must include the meaning of being superimposed along the first horizontal direction and / or superimposed along the second horizontal direction.

[0049] Furthermore, the statement that Configuration A is exposed from Configuration B should be understood as meaning that Configuration A is exposed from Configuration B, not that Configuration A is exposed from the entire product. In other words, when Configuration A is stated to be exposed from Configuration B, it should be understood to mean that Configuration A is covered by at least a portion of Configuration C.

[0050] Furthermore, when it is stated that Component A 'contacts' Component B, this may include not only cases where the component 'contacts' the other component directly, but also cases where it 'contacts' due to another component located between the component and the other component. Therefore, if Component A is to be understood only as 'directly contacting' Component B, it is described as 'directly contacting'.

[0051] In addition, when it is stated that configuration A is 'covered' by configuration B, it should be understood that configuration A is covered by configuration B, and that the part intended for the function and purpose to be resolved is covered, and unless there are special circumstances, it should not be understood that the entire configuration A is covered by configuration B.

[0052] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this application.

[0053] Hereinafter, a permanent magnet according to an embodiment is described with reference to the drawings. The permanent magnet may be referred to as a 'magnetic body', 'magnet', 'magnetic member', 'sintered magnet', etc.

[0054] In addition, embodiments of the present invention can be applied to various fields of application. For example, permanent magnets according to embodiments of the present invention can be used in various fields such as electronic information, the automotive industry, medical devices, energy, and transportation. For example, permanent magnets according to the embodiments can be applied to products such as machine tools, electronic information devices, home appliances, mobile phones, motors for robots, wind turbines, small motors for automobiles, and drive motors. That is, permanent magnets can be applied to various components that utilize magnetic force, such as magnets in the joints or motors of humanoids, magnets in camera module (CM) actuators, motors of vehicles, transformers, and inductors.

[0055] Furthermore, when the permanent magnet according to the embodiment is applied to each of the aforementioned fields or products, the reliability of the product / application can be easily secured through improved magnetic properties (coercivity, etc.) as described below. Furthermore, the permanent magnet can easily satisfy the characteristics of each field or application (or component) and provide improved technical interoperability or compatibility with the technology required in each field (e.g., vehicles, robots, electronic devices, machine tools, energy devices, etc.).

[0056] FIG. 1 is a perspective view of a permanent magnet according to an embodiment, FIG. 2 is a view taken by cutting along AA' in FIG. 1, and FIG. 3 is a view taken by cutting along BB' in FIG. 1.

[0057] Referring to FIGS. 1 to 3, a permanent magnet (100) according to an embodiment may include a base magnet (110), a barrier layer (120), and a coating layer (130).

[0058] First, the base magnet (110) may be an abc magnetic material. Here, a may include a rare earth element. b may include a transition element. And c may include boron (B).

[0059] Specifically, a may also include light rare earth elements. For example, a may be at least one of La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, or Lu. As an example, a may be neodymium (Nd).

[0060] b may include any one of the transition elements. For example, b may be iron (Fe). Accordingly, as an example, the base magnet (110) may be NdFeB.

[0061] The base magnet (110) can have various shapes. For example, the base magnet (110) can have various shapes such as a cube or a cylinder.

[0062] The barrier layer (120) may be positioned on the base magnet (110). The barrier layer (120) may be formed on the outer surface of the base magnet (110). Accordingly, the barrier layer (120) may cover at least one surface of the base magnet (110). For example, the barrier layer (120) may be laminated over the entire outer surface of the base magnet (110).

[0063] The barrier layer (120) may include an amorphous material. In an example, the barrier layer (120) may include an insulating material such as an amorphous metal, metal alloy, or resin. For example, the barrier layer (120) may include nickel (Ni), copper (Cu), or resin. By having a random atomic arrangement, the barrier layer (120) can more effectively suppress crystal propagation. For example, when the barrier layer (120) is in direct contact between the coating layer (130) and the base magnet (110), due to crystal propagation, either the coating layer (130) or the base magnet (110) may follow the crystallization of the other, thereby degrading the magnetic properties of the permanent magnet and reducing mechanical reliability. In an example, the barrier layer (120) may be positioned between the coating layer (130) and the base magnet (110), so that the coating layer (130) may have a face-centered cubic (FCC) structure. Accordingly, permanent magnets can provide stability against temperature changes and offer enhanced corrosion resistance and improved mechanical reliability while maintaining magnetic properties.

[0064] The coating layer (130) may be located on the barrier layer (120). The coating layer (130) may be formed on the outer surface of the barrier layer (120). The coating layer (130) may be spaced apart from the base magnet (110) in at least a portion of the permanent magnet. For example, the coating layer (130) may be located over the entire outer surface of the barrier layer (120). Accordingly, the coating layer (130) may be located at the outermost side of the barrier layer (120) and the base magnet (110) in the permanent magnet (100).

[0065] The coating layer (130) is a hard magnetic material with a low temperature demagnetization rate and may include a metal having hard magnetism or a compound containing a metal. For example, the coating layer (130) may include rare earth elements, metals belonging to the fourth period of the periodic table, and compounds thereof. As an example, the coating layer (130) may include samarium cobalt (SmCo). Accordingly, the coating layer (130) is SmCo5 or Sm2Co 17 It may include. With this configuration, the permanent magnet can provide improved performance and reliability at high temperatures. Additionally, the coating layer (130) may be made of a hard magnetic material with a low temperature demagnetization rate. Thus, the coating layer (130) can easily reduce magnetic degradation of the permanent magnet in a high-temperature environment with a low temperature demagnetization rate while preventing oxidation of the base magnet (110).

[0066] Additionally, the coating layer (130) may have a crystal structure different from that of the base magnet (110). For example, the base magnet (110) may have an orthorhombic structure with NdFeB, and the coating layer (130) may have a hexagonal structure with SmCo. Accordingly, when the coating layer (130) is located directly on the base magnet (110), crystal propagation between the base magnet (110) and the coating layer (130) occurs at the outer edge of the base magnet (110) as described above, which may degrade magnetic properties and cause phenomena such as edge cracking. Accordingly, the permanent magnet (100) according to the present embodiment can provide the effect of improving both magnetic properties and reliability by preventing magnetic degradation in a high-temperature environment with a low temperature demagnetization rate through the coating layer (130) while simultaneously suppressing crystal propagation to the coating layer (130) through the barrier layer (120).

[0067] In addition, in the permanent magnet (100) according to the embodiment, the base magnet (110), barrier layer (120), and coating layer (130) may be sequentially stacked from the center outward. In cross-section, the first direction may correspond to the 'X-axis direction', the second direction may correspond to the 'Y-axis direction', and the third direction may correspond to the 'Z-axis direction'.

[0068] In the embodiment, the length of the base magnet (110) may be greater than the length of the coating layer (130) or the barrier layer (120). Also, the length of the coating layer (130) may be greater than the length of the barrier layer (120).

[0069] For example, in the horizontal direction (e.g., the first direction), the length (T1a) of the base magnet (110) may be greater than the length (T2) of the barrier layer (120) or the length (T3) of the coating layer (130). In this case, the length (T1a) of the base magnet (110) may be at least 10 times the length (T3) of the coating layer (130). And the length (T3) of the coating layer (130) may be at least twice the length (T2) of the barrier layer (120).

[0070] And the length (T1b) of the base magnet in the vertical direction (e.g., third direction) may be greater than the length (T2) of the barrier layer (120) or the length (T3) of the coating layer (130) in the third direction (Z-axis direction). In this case, the length (T1b) of the base magnet (110) may be at least 30 times the length (T3) of the coating layer (130). And the length (T3) of the coating layer (130) may be at least twice the length (T2) of the barrier layer (120).

[0071] FIG. 4 is a graph of performance (HcJ, intrinsic coercivity (intrinsic force)) depending on whether a coating layer of first thickness is formed on a base magnet, FIG. 5 is a graph of performance (HcJ, intrinsic coercivity (intrinsic force)) depending on whether a coating layer of second thickness is formed on a base magnet, FIG. 6(a) is a photograph of a permanent magnet after a coating layer of first thickness is formed on a base magnet, FIG. 6(b) is a photograph of a permanent magnet after a coating layer of second thickness is formed on a base magnet, FIG. 7 is the result of X-ray Diffraction (XRD) analysis after a coating layer is formed on a base magnet, and FIG. 8 is a graph of performance (HcJ, intrinsic coercivity (intrinsic force)) depending on before and after heat treatment for forming a coating layer on a base magnet.

[0072] Referring to FIG. 4, it can be seen that the performance (HcJ, intrinsic coercivity (intrinsic force)) differs when a coating layer of a first thickness (e.g., 5 μm) is formed on the base magnet (coating layer O) and when no coating layer is formed (coating layer X). In this case, the coating layer is formed directly on the base magnet.

[0073] Specifically, considering the magnetic flux density (J[T]) relative to the external magnetic field strength (e.g., H[kA / m]), it can be seen that the absence of a coating layer (coating layer X) exhibits a wider and higher magnetization value than the presence of a coating layer (coating layer O). In other words, the absence of a coating layer (coating layer X) indicates that the magnetism is relatively stronger than that of the presence of a coating layer (coating layer O). This suggests that the performance of the permanent magnet is actually degraded by the formation of a coating layer.

[0074] Table 1 below shows the experimental results for residual magnetic flux density (Br [T]), normal coercivity (force) (HcB [kA / m]), intrinsic coercivity (intrinsic force) (HcJ [kA / m]), and energy density ((BH)max [kJ / m³]) for the formation and non-formation of a coating layer of a first thickness (e.g., 5 µm) on a base magnet.

[0075] Measurement Temperature (°CBr [T] HcB [kA / m] HcJ [kA / m] (BH) max [kJ / m³] Sputtering Sputter + Annealing (500°C Sputtering Sputter + Annealing (500°C Sputtering Sputter + Annealing (500°C Sputtering Sputter + Annealing (500℃RT(25)1.3891.3721079.5538.31794.91463.9375.0157.9601.3411.3141029.1491.61281.71065.734 5.9109.6801.3141.280996.9470.31088.6898.0329.496.31001.2681.243894.8447.9905.7746.9303.587.0

[0076] In Table 1, 'before sputtering' indicates the absence of a coating layer, while the parts where both 'sputtering' and 'annealing' are listed indicate the formation of a coating layer. Referring to Table 1, it can be seen that when a coating layer is formed on the base magnet, the overall magnetic performance (magnetic flux density, coercivity, etc.) decreases compared to when it is not formed. Furthermore, it can be seen that the magnetic performance deteriorates even more significantly with increasing temperature when a coating layer is formed compared to when it is not formed. Referring to Figure 5, it can be seen that the performance (HcJ, intrinsic coercivity (intrinsic coercivity)) differs between the case where a coating layer of a second thickness (e.g., 10 μm) is formed on the base magnet (coating layer O) and the case where a coating layer is not formed (coating layer X). In this case, the coating layer was formed directly on the base magnet.

[0077] Specifically, considering the magnetic flux density (J[T]) relative to the external magnetic field strength (e.g., H[kA / m]), it can be seen that the absence of a coating layer (coating layer X) exhibits a wider and higher magnetization value than the presence of a coating layer (coating layer O). In other words, the absence of a coating layer (coating layer X) indicates that the magnetism is relatively stronger than that of the presence of a coating layer (coating layer O). This suggests that the performance of the permanent magnet is actually degraded by the formation of a coating layer.

[0078] Table 2 below shows the experimental results for residual magnetic flux density (Br [T]), normal coercivity (force) (HcB [kA / m]), intrinsic coercivity (intrinsic force) (HcJ [kA / m]), and energy density ((BH)max [kJ / m³]) for the formation and non-formation of a coating layer of a second thickness (e.g., 10 µm) on a base magnet.

[0079] Measured Temperature (°CBr [T] HcB [kA / m] HcJ [kA / m] (BH) max [kJ / m³] Before Sputter Sputter + Annealing 600°C Before Sputter Sputter + Annealing 600°C Before Sputter Sputter + Annealing 600°C Before Sputter Sputter + Annealing 600℃RT(25)1.3891.3231078.3422.01788.61338.7374.682.4601.3401.2251028.0384.71285.2934.6344 .765.5801.3101.166993.1361.81082.4760.0326.958.51001.2751.105891.6336.4903.2606.0306.251.9

[0080] In Table 2, 'before sputter' indicates the absence of a coating layer, while the parts where both 'sputter' and 'annealing' are listed indicate the formation of a coating layer. Referring to Table 2, it can be seen that when a coating layer is formed on the base magnet, as in the first thickness, the overall magnetic performance (magnetic flux density, force, etc.) decreases compared to when it is not formed. Furthermore, it can be seen that as the temperature increases with the formation of the coating layer compared to when it is not formed, the magnetic performance deteriorates even more significantly. Referring to Figures 6(a) and 6(b), it can be seen that when a coating layer is formed directly on the base magnet, cracking occurs at the edge of one surface regardless of the thickness or annealing temperature. In particular, it can be seen that when the second thickness is formed at a high annealing temperature, the cracking phenomenon occurs more significantly compared to the first thickness.

[0081] Referring to Fig. 7, the results of X-ray diffraction (XRD) analysis were measured after forming a coating layer on the base magnet. When comparing the cases where annealing was performed at an annealing temperature (500°C, 600°C) after sputtering (A, C, D, F) with the cases where annealing was not performed (raw, B, E), it can be seen that the material changes into face-centered cubic (FCC) Co depending on the annealing, i.e., heat treatment. In other words, the material located on the surface of the base magnet before heat treatment may be amorphous Co, but it can be seen that it changes into FCC Co depending on the heat treatment. As such, it can be seen that crystal changes occur depending on the heat treatment when forming the coating layer.

[0082] Referring further to Fig. 8, it can be seen that there is a difference in performance between the pre-sputtering (A, C) and post-sputtering (B, D) heat treatment states. It can be seen that the electrical properties (flux density, etc.) after heat treatment (B, D) are lower compared to the pre-sputtering (A, C) state states. In other words, as the cobalt (Co) present on the surface of the base magnet crystallizes during heat treatment, the magnetic interaction (exchange coupling) between the atoms inside the cobalt (Co) becomes stronger. Consequently, an inverse magnetic field (magnetic field in the opposite direction) is applied, causing the magnetization direction of the cobalt (Co) to start reversing first. As a result, it can be seen that the strength of the magnetic field (flux density) emitted from the entire magnet decreases as the cobalt (Co) undergoes magnetic reversal first.

[0083] In addition, it can be seen that the thicker the coating layer, the more the crystallization of cobalt (Co) increases, leading to greater performance degradation.

[0084] Thus, the permanent magnet according to the embodiment can provide the effect of easily reducing magnetic degradation of the permanent magnet in a high-temperature environment with a low temperature demagnetization rate while preventing oxidation.

[0085] FIG. 9 is a flowchart of a manufacturing method for manufacturing a permanent magnet according to an embodiment.

[0086] Referring to FIG. 9, a method (200) for manufacturing a permanent magnet according to an embodiment may include the steps of providing a base magnet (S210), forming a barrier layer (S220), and forming a coating layer (S230).

[0087] First, a base magnet can be prepared (S210). For example, an abc pre-magnet can be manufactured. As described above, the abc pre-magnet may be a sintered magnet. The base magnet can be formed by processing an abc ingot into powder and then sintering the powder. For example, an abc sintered magnet can be manufactured by casting an abc alloy ingot with abc magnetic powder and then grinding it. Specifically, the ingot can be melted, the molten alloy can be formed into a strip shape, etc., and then ground with a milling device, etc., to form the abc magnetic powder. Alternatively, it may be manufactured by an HDDR process, etc. Then, the abc magnetic powder (or powder) can be molded into a desired shape to manufacture an abc base magnet. During molding, a magnetic field may be applied if necessary. A sintering process may be performed during molding. The sintering process is not limited to a specific method. For example, the sintering process may include press sintering, hot isostatic sintering, plasma sintering, microwave sintering, etc. Through the sintering process, the magnetic powder can be densely bound, and the base magnet can be densified. As a result, an ABC-based base magnet can be formed.

[0088] And a barrier layer can be formed on the surface of the base magnet (S220). The barrier layer can be formed by various methods. For example, the barrier layer can be formed by deposition or plating (electroless plating or electrolytic plating).

[0089] Furthermore, a coating layer can be formed on the outer surface of the barrier layer (S230). The coating layer can be formed by various methods such as sputtering or plating.

[0090] FIG. 10 is a drawing illustrating a permanent magnet according to another embodiment.

[0091] Referring to FIG. 10, the permanent magnet may include a base magnet (110), a barrier layer (120), and a coating layer (130) as described above. Except for the details described below, the above details may be applied.

[0092] A barrier layer (120) may be formed on a base magnet (110). The barrier layer (120) may have different thicknesses depending on the location. For example, the barrier layer (120) may have a thickness greater at the edge than at the center relative to one side of the base magnet (110). With this configuration, changes in the crystal structure of the coating layer at the edge can be suppressed more easily. Thus, the permanent magnet can prevent magnetic degradation in a high-temperature environment with a low temperature demagnetization rate through the coating layer (130), and suppress crystal propagation to the coating layer (130) through the different thicknesses of the barrier layer (120) in different regions, thereby providing the effect of improving both magnetic properties and reliability.

[0093] Additionally, the coating layer (130) may be located in some areas on the base magnet (110). That is, some parts of the surface of the base magnet (110) may be in contact with the coating layer (130), while other parts may be in contact with the barrier layer (120).

[0094] The barrier layer (120) may be positioned along the edge relative to one side of the base magnet (110). For example, the barrier layer (120) may be positioned only at the edge on one side of the base magnet (110). Also, the barrier layer (120) may not be positioned in the center on one side of the base magnet (110). And the coating layer (130) may be positioned in the center of one side of the base magnet (110) so that the coating layer (130) and the surface of the base magnet (110) can come into contact.

[0095] FIG. 11 is a drawing illustrating a motor with a permanent magnet applied according to an embodiment, and FIG. 12 is a drawing illustrating an actuator with a permanent magnet applied according to an embodiment.

[0096] The permanent magnet according to the embodiment can be applied to various fields. Referring to FIG. 11, the permanent magnet can be applied to a motor (M). For example, the motor (M) may include a stator (402), a stator winding slot (404), a permanent magnet (406), and a rotor (408).

[0097] A permanent magnet can be placed within the motor (M). In particular, the rotor (408) is a member installed in the space through which the stator (402) is penetrated, and may be included to rotate by receiving the electromagnetic force generated as current flows through the coil wound on the stator (402). Furthermore, the motor with the permanent magnet can have improved durability in various environments such as vehicles and generators.

[0098] Referring to FIG. 12, a permanent magnet can be applied to an actuator (AC). For example, the actuator (AC) may include various magnetic materials (MG) to generate a coupling force with a lens, lens assembly, etc., or a yoke, etc. For example, an image stabilization operation and / or an autofocus operation can be implemented by the actuator (AC). In this case, the permanent magnet of the embodiment can be used as a magnetic material (MG).

[0099] As such, the permanent magnet according to the embodiment can provide improved reliability by being applied to various magnetic components such as magnets in the joints or motors of a humanoid, magnets in camera module (CM) actuators, motors, transformers, and inductors of a vehicle.

[0100] The features, structures, effects, etc. described in the above-described embodiments are included in at least one embodiment of the present invention and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects, etc. exemplified in each embodiment may be combined or modified and implemented in other embodiments by a person skilled in the art to which the embodiments belong. Therefore, details regarding such combinations and modifications should be interpreted as being included within the scope of the present invention.

[0101] Furthermore, although the invention has been described above with reference to embodiments, this is merely illustrative and does not limit the invention. Those skilled in the art will understand that various modifications and applications not exemplified above are possible within the scope of the essential characteristics of the embodiments. For example, each component specifically shown in the embodiments may be modified and implemented. Differences related to such modifications and applications should be interpreted as being included within the scope of the invention as defined in the appended claims.

Claims

1. A base magnet comprising abc (a includes a rare earth element, b includes a transition element, and c includes boron (B); A barrier layer disposed on the base magnet; and A coating layer disposed on the above barrier layer; comprising The above barrier layer is a permanent magnet comprising an amorphous material.

2. In Paragraph 1, The above a is neodymium (Nd), and The above b is a permanent magnet made of iron (Fe).

3. In Paragraph 1, A permanent magnet whose thickness of the base magnet is greater than the thickness of the coating layer or the thickness of the barrier layer.

4. In Paragraph 1, A permanent magnet in which the thickness of the coating layer is greater than the thickness of the barrier layer.

5. In Paragraph 1, The above coating layer is SmCo5 or Sm2Co 17 A permanent magnet containing 6. In Paragraph 1, The coating layer is a permanent magnet having a crystal structure different from that of the base magnet.

7. In Paragraph 1, The above barrier layer is a permanent magnet comprising an amorphous metal or insulating resin.

8. In Paragraph 1, The barrier layer is a permanent magnet located at the edge of one side of the base magnet.

9. In Paragraph 1, A permanent magnet in which the thickness of the barrier layer at the edge on one side of the base magnet is greater than the thickness of the barrier layer at the center.

10. In Paragraph 1, The above coating layer is a permanent magnet in contact with one surface of the base magnet.

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