Soft magnetic material and method for manufacturing the same

Abstract

To provide a soft magnetic material capable of improving a degree of freedom in magnetic circuit design without performing rolling.SOLUTION: A soft magnetic material is formed by lamination modeling using a soft magnetic powder material, and a magnetization easy axis <100> is aligned in three directions: a first direction which is a lamination modeling direction; a second direction perpendicular to the first direction; and a third direction perpendicular to both the first direction and the second direction. A method for manufacturing the soft magnetic material includes: a first step of forming a powder material layer composed of the soft magnetic powder material; a second step of preliminarily heating the whole powder material layer; and a third step of irradiating a portion to be modeled in the preliminarily heated powder material layer with an electron beam or a laser beam to melt and solidify the portion irradiated with the electron beam or the laser beam.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a soft magnetic material and a method for manufacturing the same. [Background technology]

[0002] In soft magnetic materials, the specific crystal direction that is easy to magnetize is called the axis of easy magnetization. For example, in the case of iron (Fe), a typical soft magnetic material, the crystal axis <100> The direction is the easy axis of magnetization.

[0003] As a method for aligning the easy axis of magnetization in a specific crystal direction, a method of rolling and heat treating a soft magnetic material is known. For example, the easy axis of magnetization of iron is aligned in a specific crystal direction by rolling and heat treating. <100> By aligning the grains in the rolling direction, it is possible to obtain a grain-oriented electrical steel sheet having good magnetic properties in the rolling direction.

[0004] In recent years, a method of additive manufacturing using metal powder material has been attracting attention as a method for manufacturing metal parts having complex shapes that cannot be formed by rolling.

[0005] For example, Patent Document 1 discloses an additive manufacturing method for a three-dimensional object, which includes the steps of forming a layer of inorganic powder material made of a NiMo alloy or the like, irradiating the layer of inorganic powder material with an electron beam, laser light, and / or arc discharge in parallel in a certain direction, and creating a seed crystal by said irradiation. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2018-115090 Summary of the Invention [Problem to be solved by the invention]

[0007] In the conventional method of rolling and heat treating steel materials used in the manufacture of grain-oriented electrical steel sheets, the easy axis of magnetization <100> The alignment of the magnetic flux is limited to only one direction, the rolling direction. Therefore, the soft magnetic materials produced by the above-mentioned conventional method are limited in their applications to circuits in which magnetic flux flows in only one direction, such as wound transformer cores, and the degree of freedom in magnetic circuit design is low. Furthermore, the above-mentioned conventional method cannot be used for materials that have good magnetic properties but are poorly workable and cannot be rolled, and is therefore limited to materials that can be rolled.

[0008] The present invention has been made in view of the above-mentioned problems, and aims to provide a soft magnetic material that can improve the degree of freedom in magnetic circuit design without rolling. [Means for solving the problem]

[0009] One aspect of the present invention is A soft magnetic body obtained by layered manufacturing using a soft magnetic powder material, The magnetization easy axis is aligned in three directions: a first direction, which is the additive manufacturing direction; a second direction perpendicular to the first direction; and a third direction perpendicular to the first direction and the second direction. <100> are available, It is in soft magnetic materials.

[0010] Another aspect of the present invention is A first step of forming a powder material layer made of soft magnetic powder material; a second step of preheating the entire powder material layer; a third step of irradiating an electron beam or laser light onto a portion of the preheated powder material layer to be molded, thereby melting and solidifying the portion irradiated with the electron beam or the laser light; The method for manufacturing the soft magnetic material is as follows. [Effects of the Invention]

[0011] The soft magnetic body is formed by layer-by-layer manufacturing using a soft magnetic powder material, and has an easy axis of magnetization in three directions: a first direction, which is the layer-by-layer manufacturing direction; a second direction perpendicular to the first direction; and a third direction perpendicular to the first and second directions. <100> Therefore, the soft magnetic material can form magnetic paths in the three directions, and the axis of easy magnetization is aligned only in one direction, the rolling direction. <100> This allows for greater freedom in magnetic circuit design compared to soft magnetic materials, which can only form magnetic paths in one direction.

[0012] The method for producing the soft magnetic body has the above-described configuration, and therefore, the method for producing the soft magnetic body can produce the soft magnetic body without rolling, which allows for greater freedom in magnetic circuit design. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a diagram for explaining a case where the scanning pattern of the electron beam or laser light is a cross snake in the third step of the method for producing a soft magnetic material according to the second embodiment. [Figure 2] FIG. 2 is a diagram for explaining a measurement method by EBSD of the soft magnetic material in Experimental Example 1. [Figure 3] FIG. 3 shows the results of EBSD measurement of the soft magnetic materials of Samples 1 to 7 obtained in Experimental Example 1. As shown in FIG. [Figure 4] FIG. 4 shows the results of EBSD measurement of the soft magnetic materials of Samples 8 to 13 obtained in Experimental Example 1. As shown in FIG. [Figure 5] FIG. 5 is a diagram showing the relationship between the linear energy (vertical axis) and the scanning speed (horizontal axis) of the electron beam during additive manufacturing of the soft magnetic bodies of Samples 1 to 13 obtained in Experimental Example 1. [Figure 6] FIG. 6 is an explanatory diagram showing the shape of a sample for evaluating magnetic properties of the soft magnetic material obtained in Experimental Example 2. [Figure 7] FIG. 7 is a diagram showing the measurement results of the magnetic properties of the soft magnetic material of Sample A obtained in Experimental Example 2. [Figure 8]FIG. 8 is a diagram showing the measurement results of the magnetic properties of the soft magnetic material of Sample C obtained in Experimental Example 2. [Figure 9] FIG. 9 is a diagram showing the results of measuring the crystal orientation of the entire central cross section of the soft magnetic material of Sample 12 in Experimental Example 3 by EBSD. DETAILED DESCRIPTION OF THE INVENTION

[0014] (Embodiment 1) The soft magnetic body of embodiment 1 will be described. The soft magnetic body of this embodiment is produced by layer-by-layer manufacturing using a soft magnetic powder material. That is, the soft magnetic body of this embodiment is produced by repeatedly melting and solidifying (or coagulating) the soft magnetic powder material, which is a powdered soft magnetic material, and layering it to produce a three-dimensional shape.

[0015] The soft magnetic material of this embodiment has an easy axis of magnetization in three directions: a first direction, a second direction, and a third direction. <100> The easy axis of magnetization is a specific crystal direction that is easy to magnetize, and in the soft magnetic material of this embodiment, <100> It is a direction. <100> is a collective expression of the

[0100] , [-100],

[0010] , [0-10],

[0001] , and [00-1] directions. <100> is the normal direction of the {100} plane. {100} collectively represents the (100), (-100), (010), (0-10), (001), and (00-1) planes. Note that the "-" (minus) sign before the numbers above usually refers to the bar above the number in the Miller indices of a crystal. Due to restrictions on the application format, a bar cannot be placed above the number, so the "-" sign is used.

[0016] The soft magnetic material of this embodiment is obtained by additive manufacturing using the additive manufacturing method as described above, and the first direction is the additive manufacturing direction (stacking direction). The second direction is a direction perpendicular to the first direction. In this embodiment, the second direction can be a direction parallel to the scanning direction of the heat source during additive manufacturing. The heat source is used to melt the soft magnetic powder material. Furthermore, the third direction is a direction perpendicular to the first and second directions. The third direction can also be referred to as a normal direction perpendicular to the first and second directions. In this embodiment, the third direction can be a normal direction perpendicular to the additive manufacturing direction and the scanning direction of the heat source.

[0017] In the soft magnetic material of this embodiment, the easy axis of magnetization <100> Whether or not the orientations are aligned in the above three directions can be determined by analyzing the center of a central cross section of the soft magnetic material, which is parallel to the first direction and passes through the center of the soft magnetic material, using electron backscatter diffraction (hereinafter, sometimes abbreviated as EBSD). Details of the EBSD measurement method will be described later in the experimental examples.

[0018] In the soft magnetic body of this embodiment, a metal material (here, the term "metal" includes alloys; hereinafter, this is omitted) whose crystal structure is a body-centered cubic lattice structure is preferably used as the soft magnetic powder material. Specifically, the soft magnetic powder material can be mainly composed of Fe. Note that "mainly composed of Fe" means that Fe is 50% by mass or more in the chemical composition of the soft magnetic powder material. In this case, the soft magnetic powder material may be pure iron or an Fe-based alloy containing 50% by mass or more of Fe. When the soft magnetic powder material is mainly composed of Fe, the easy axis of magnetization of Fe is preferably oriented along the axis of magnetization of Fe. <100> By aligning in the above three directions, a soft magnetic material having excellent magnetic properties in the above three directions can be obtained.

[0019] The soft magnetic powder material containing Fe as the main component can contain, in addition to Fe, at least one element selected from the group consisting of Si, C, Mn, P, S, Cu, Ni, Cr, Mo, O, Al, Ga, and N. In this case, there are advantages such as improved magnetism and easier stable formation of a ferrite structure.

[0020] A soft magnetic powder material containing Fe as a main component can preferably contain Si from the viewpoints of improving magnetic permeability and reducing magnetostriction. In this case, the Si content can be preferably 2 mass% or more, more preferably 4.5 mass% or more, and even more preferably 6 mass% or more, from the viewpoint of improving magnetic properties such as magnetic permeability. Furthermore, the Si content can be preferably 15 mass% or less, more preferably 11 mass% or less, and even more preferably 7.5 mass% or less, from the viewpoint of easily maintaining the crystal structure as a body-centered cubic lattice structure. In this embodiment, the upper and lower limits of the content of the component elements can be arbitrarily combined. The same applies hereinafter.

[0021] The soft magnetic powder material containing Fe as the main component can contain at least one element selected from the group consisting of C, Mn, P, and S. As described above, when the soft magnetic powder material containing Fe as the main component contains Si, it can also contain at least one element selected from the group consisting of C, Mn, P, and S. C, Mn, P, and S can be contained as inevitable impurity elements.

[0022] The contents of C, Mn, P, and S can each be set to preferably 0.001% by mass or more, more preferably 0.005% by mass or more, and even more preferably 0.010% by mass or more, since excessive reductions in these contents will increase costs. Furthermore, the contents of C, Mn, P, and S can each be set to preferably 0.035% by mass or less, more preferably 0.025% by mass or less, and even more preferably 0.015% by mass or less, from the viewpoint of suppressing embrittlement.

[0023] The soft magnetic material of this embodiment can be suitably used, for example, in the stator core of a motor, an electromagnetic actuator, a magnetic sensor, a transformer core, etc. When the soft magnetic material of this embodiment is applied to, for example, the stator core of a motor to which it is difficult to apply grain-oriented electromagnetic steel sheets, the axis of easy magnetization <100> The alignment of the magnetic flux density in three directions and the increased freedom in magnetic circuit design through free-form fabrication using additive manufacturing methods make it possible to achieve high performance and miniaturization of the stator core. Furthermore, when the soft magnetic material of this embodiment is applied to, for example, an electromagnetic actuator or a magnetic sensor, the improved magnetic properties can improve responsiveness.

[0024] The soft magnetic body of this embodiment is manufactured by additive manufacturing using soft magnetic powder material, and has easy axes of magnetization in three directions: a first direction, which is the additive manufacturing direction; a second direction perpendicular to the first direction; and a third direction perpendicular to the first and second directions. <100> Therefore, the soft magnetic material of this embodiment can form magnetic paths in the above three directions, and has an easy axis of magnetization in only one direction, the rolling direction. <100> This allows for greater freedom in magnetic circuit design compared to soft magnetic materials of comparable types that can only form magnetic paths in one direction.

[0025] For other configurations and effects, it is possible to appropriately refer to the description of the method for manufacturing the soft magnetic material of embodiment 2. The soft magnetic material of this embodiment, which can improve the degree of freedom in magnetic circuit design, can be manufactured by the method for manufacturing the soft magnetic material of embodiment 2 without performing rolling.

[0026] (Embodiment 2) A method for manufacturing a soft magnetic body of embodiment 2 (hereinafter sometimes referred to as the manufacturing method of this embodiment) will be described. The manufacturing method of this embodiment includes a first step, a second step, and a third step. The manufacturing method of this embodiment is a method for manufacturing a soft magnetic body by additive manufacturing.

[0027] The first step is to form a powder material layer made of soft magnetic powder material.

[0028] In the first step, the powder material layer can be formed, for example, by supplying soft magnetic powder material to a building chamber of a three-dimensional additive manufacturing device and spreading it in layers using a layer-forming member such as a blade member or roller member of the device. When the powder material layer is the first layer, the powder material layer is usually formed on a stage of the device. When the powder material layer is the second or subsequent layer, the powder material layer is usually formed on a lower powder material layer that includes a melted and solidified portion of the part to be built. The stage can be configured to be able to descend downward, for example, each time a powder material layer is formed.

[0029] The first step is preferably carried out in an inert gas atmosphere or a vacuum atmosphere from the viewpoints of preventing oxidation of the soft magnetic powder material, ensuring work safety by suppressing dust explosions, and stably generating an electron beam when an electron beam is used as a heat source. Examples of inert gases include noble gases (rare gases) such as He gas, Ne gas, and Ar gas, and nitrogen gas.

[0030] The soft magnetic powder material used as the raw material of the powder material layer is a powdered soft magnetic material, and the description of the first embodiment can be referred to for the material.

[0031] Furthermore, the particle size of the soft magnetic powder material used as the raw material for the powder material layer is preferably 200 μm or less from the viewpoints of the formability of the powder material layer, suppression of defects in the shaped body, and stabilization of density. In other words, the particle size of the soft magnetic powder material is preferably adjusted to be within a particle size range of 200 μm or less. The particle size of the soft magnetic powder material is more preferably 150 μm or less, and even more preferably 105 μm or less. On the other hand, from the viewpoints of stability during powder laying (suppression of deterioration of powder flowability), the particle size of the soft magnetic powder material is preferably 25 μm or more. The particle size of the soft magnetic powder material is more preferably 35 μm or more, and even more preferably 45 μm or more. The particle size of the soft magnetic powder material can be adjusted, for example, by classification processing.

[0032] The second step is to preheat the entire powder material layer.

[0033] The preheating in the second step has the significance of suppressing residual stress in the soft magnetic material, suppressing powder scattering due to charging, slowing down the solidification rate and promoting epitaxial growth, etc. The preheating in the second step may be performed using any heating means as long as it can heat the entire powder material layer without melting the soft magnetic powder material.

[0034] In the second step, the entire powder material layer can be preheated by irradiating the entire powder material layer with an electron beam or laser light. According to this configuration, the entire powder material layer can be preheated using the electron beam or laser light in a three-dimensional additive manufacturing device that uses an electron beam or laser light as a heat source for melting the soft magnetic powder material, so that the entire powder material layer can be preheated to a predetermined temperature relatively easily.

[0035] In the second step, the entire powder material layer can also be preheated using a base plate (sometimes referred to as a powder bed) for forming the powder material layer. With this configuration, the entire powder material layer can be preheated using the base plate placed on the stage of the three-dimensional additive manufacturing device, making it possible to preheat the entire powder material layer to a predetermined temperature relatively easily.

[0036] Specifically, preheating the entire powder material layer using a base plate can be performed, for example, by irradiating the base plate with an electron beam or laser light to heat the base plate. In this case, even if the base plate itself does not have a heating function, the entire powder material layer can be preheated relatively easily by using the electron beam or laser light in a 3D additive manufacturing device that uses an electron beam or laser light as a heat source. Preheating the entire powder material layer using a base plate can also be performed by heating the base plate with a heater and then heating the entire powder material layer using this heated base plate. In this case, the entire powder material layer can be preheated using the base plate without irradiating it with an electron beam or laser light. Note that preheating the entire powder material layer using a base plate is suitable for preheating the first powder material layer.

[0037] In the second step, the preheating temperature can be set to 600°C or higher. In this case, residual stress in the soft magnetic material can be easily suppressed. The preheating temperature can be preferably set to 800°C or higher, more preferably 900°C or higher, and even more preferably 970°C or higher. The preheating in the second step does not melt the soft magnetic powder material that constitutes the powder material layer, and the upper limit of the preheating temperature is not particularly limited as long as it is a temperature below the temperature at which the soft magnetic powder material melts. The preheating temperature can be, for example, 1450°C or lower, preferably 1100°C or lower, and more preferably 1000°C or lower. In this embodiment, the upper and lower limit values ​​of the preheating temperature can be arbitrarily combined.

[0038] The second step is preferably carried out in an inert gas atmosphere or a vacuum atmosphere, similar to the first step.

[0039] The third step is a step of irradiating the portion of the preheated powder material layer to be molded with an electron beam or laser light, thereby melting and solidifying the portion irradiated with the electron beam or laser light.

[0040] In the third step, the electron beam or laser light may be irradiated under the condition of a line energy of 1.5 J / mm or more. Also, in the third step, the electron beam or laser light may be irradiated under the condition of a scan speed of 450 mm / s or more and 750 mm / s or less. With these configurations, the easy axis of magnetization <100> In particular, in the third step, it is preferable to irradiate the electron beam or laser light under conditions that satisfy a linear energy of 1.5 J / mm or more and a scanning speed of 450 mm / s to 750 mm / s. With this configuration, the easy axes of magnetization are more easily aligned in the three directions than when the linear energy is 1.5 J / mm or more and the scanning speed is less than 450 mm / s, or when the linear energy is 1.5 J / mm or more and the scanning speed is more than 750 mm / s. <100> In other words, with this configuration, the easy axis of magnetization <100> is more likely to be oriented in the above three directions.

[0041] To ensure the above-described effects, the linear energy may be set to preferably 1.6 J / mm or more, more preferably 1.7 J / mm or more, and even more preferably 1.8 J / mm or more. To ensure the above-described effects, the linear energy may be set to preferably 3.2 J / mm or less, more preferably 3.1 J / mm or less, and even more preferably 3 J / mm or less. To ensure the above-described effects, the scanning speed may be set to preferably 475 mm / s or more, more preferably 500 mm / s or more, even more preferably 525 mm / s or more, and even more preferably 550 mm / s or more. To ensure the above-described effects, the scanning speed may be set to preferably 725 mm / s or less, more preferably 700 mm / s or less, and even more preferably 675 mm / s or less. In this embodiment, the upper and lower limit values ​​of the linear energy and the upper and lower limit values ​​of the scanning speed can be combined in any desired manner.

[0042] In the third step, the scanning pattern of the electron beam or laser light is not particularly limited. The scanning pattern of the electron beam or laser light can be a snake scan, as exemplified in FIG. 1(a). This configuration has the advantage of making the heat input and heat dissipation uniform. Note that FIG. 1 is a view from above in the additive manufacturing direction.

[0043] Furthermore, for example, when irradiating a powder material layer with an electron beam or laser light in a snake scan scanning pattern as exemplified in Fig. 1(a), when forming the next (upper) powder material layer after forming the previous (lower) powder material layer, it is preferable to perform a cross-snake scanning pattern (Fig. 1(b)) in which the electron beam or laser light is irradiated in a snake scan scanning direction perpendicular to the snake scan scanning pattern (Fig. 1(a)) used when forming the lower powder material layer. This configuration has advantages such as improved orientation, uniform heat input and heat dissipation, and improved symmetry of the shape.

[0044] The third step is preferably carried out in an inert gas atmosphere or a vacuum atmosphere, similar to the first step.

[0045] In the manufacturing method of this embodiment, if necessary, a fourth step can be added after the third step, in which the powder material layer is preheated again after being melted and solidified by irradiation with an electron beam or laser light. This configuration makes it easier to maintain the temperature preheated in the second step. This has the advantages of more stably suppressing residual stress in the soft magnetic material, suppressing powder scattering due to charging, and slowing the solidification rate to promote epitaxial growth. Note that, like the first step, the fourth step is preferably performed in an inert gas atmosphere or a vacuum atmosphere.

[0046] Regarding the third step and thereafter, basically, the first, second, and third steps, and optionally up to the fourth step, can be repeated multiple times until the soft magnetic material reaches the desired size (length in the predetermined additive manufacturing direction). This allows the soft magnetic material of embodiment 1 to be manufactured.

[0047] The method for producing the soft magnetic material of this embodiment can produce the soft magnetic material of embodiment 1, which can improve the degree of freedom in magnetic circuit design, without performing rolling.

[0048] For other configurations and effects, the description of the soft magnetic material of the first embodiment can be referred to as appropriate.

[0049] (Experimental example) The soft magnetic material and the method for producing the same according to the present disclosure will be described in more detail below using experimental examples.

[0050] <Experimental Example 1> -Preparation of soft magnetic specimens- As a soft magnetic powder material, Fe-Si powder containing Fe as the main component and Si was prepared. Specifically, the Fe-Si powder contained 6.5% by mass of Si, with the remainder consisting of Fe and unavoidable impurities. The Fe-Si powder also contained C, Mn, P, and S as unavoidable impurities. The Fe-Si powder was classified to have a particle size range of 45 μm to 105 μm. Next, using a 3D metal additive manufacturing (A2X, manufactured by Arcam, heat source: electron beam) machine, the Fe-Si powder was additively manufactured under specified additive manufacturing conditions to obtain soft magnetic bodies (Samples 1 to 13) with a rectangular shape measuring 9 to 17 mm in the additive manufacturing direction, 12 mm in the heat source scanning direction perpendicular to the additive manufacturing direction, and 12 mm in the normal direction perpendicular to both the additive manufacturing direction and the heat source scanning direction.

[0051] In the above, the additive manufacturing conditions are specifically, energy density 131.48 J / mm 2The conditions were as follows: the scan pattern was cross-snake, the layer thickness was fixed at 100-200 μm, the stage heating temperature was fixed at 900°C-970°C, and the line energy and scan speed were changed to the levels shown in Table 1 below.

[0052] Specifically, additive manufacturing was performed as follows. First, a base plate was placed on a stage in the manufacturing chamber of the device, and the entire base plate was irradiated with an electron beam in a vacuum atmosphere and preheated to 900°C to 970°C. Next, Fe-Si powder was spread in layers to form a first powder material layer. Next, the entire first powder material layer was irradiated with an electron beam and preheated again to 900°C to 970°C. Next, an electron beam was irradiated onto the portion of the preheated first powder material layer to be manufactured, and the portion irradiated with the electron beam was melted and solidified. Next, this first powder material layer (including the entire melted and solidified portion and the entire unmelted and unsolidified portion) was irradiated with an electron beam and preheated again to 900°C to 970°C. Next, the stage was lowered, and Fe-Si powder was spread in layers in the same manner as above to form a second powder material layer. Next, the entire second powder material layer was preheated to 900-970°C by irradiating it with an electron beam. The portion of the preheated second powder material layer to be molded was then irradiated with an electron beam, melting and solidifying the irradiated portion, and preheating was repeated in the same manner as above. The second layer formation process was then repeated multiple times until the length in the additive manufacturing direction was reached. Note that the preheating by electron beam irradiation was performed under conditions such that the Fe-Si powder was heated but not melted. This resulted in the soft magnetic bodies of each sample.

[0053] -Metal structure observation using EBSD- For each soft magnetic material sample obtained, metallographic observation was performed using EBSD as follows.

[0054] As shown in Figure 2(a), the sample soft magnetic material 1 is cut so as to expose a central cross section 10 that passes through the center of the soft magnetic material 1 and is parallel to the additive manufacturing direction Z (the height direction of the sample soft magnetic material 1). The cut surface is smoothed by mechanical polishing. Next, the center of the central cross section 10 of the soft magnetic material 1 is designated as an EBSD observation area S for EBSD analysis. The size of the EBSD observation area S is 5 mm in the additive manufacturing direction Z × 2 mm in the direction perpendicular to the additive manufacturing direction Z on the central cross section. In this experimental example, the bottom edge of the EBSD observation area S is at least 3.5 mm away from the bottom surface of the soft magnetic material 1. The step during EBSD measurement is 5 μm. Next, an IPF map (crystal orientation map) M is obtained for this EBSD observation area S. As shown in Figure 2(b), IPF map M represents crystal planes in color when the EBSD observation area S is viewed from the 001 direction (the direction indicated by the IPF001 arrow in Figure 2(b)), the 010 direction (the direction indicated by the IPF010 arrow in Figure 2(b)), and the 100 direction (the direction indicated by the IPF100 arrow in Figure 2(b)). Specifically, as shown in Figure 2(c), IPF map M is composed of an IPF001 image m1, an IPF010 image m2, and an IPF100 image m3 (hereinafter, collectively referred to as each IPF image) corresponding to the EBSD observation area S. While IPF map M is typically obtained as a color map, in this experimental example, the actual color IPF map M, as shown in Figure 2(c), is converted to grayscale due to limitations in the application format. In this grayscale IPF map M, the more areas that correspond to the red areas in the color IPF map M, the more {100} planes there are. <100> This means there are many directions.

[0055] Next, the average misorientation is calculated for each IPF image. The average misorientation in each IPF image represents the angle of inclination of the {001} plane. In other words, the average misorientation in each IPF image is the angle of inclination of the {001} plane relative to the viewing direction when viewed from the 001, 010, and 100 directions. <100> It represents the average angle of deviation. For example, for the {001} plane, the angle difference from the normal direction of the 001 direction is <001> This represents the same as the angular difference with respect to the 001 direction. Next, the three-direction average misorientation is calculated as the arithmetic mean of the average misorientation of each IPF image. In other words, the three-direction average misorientation is the arithmetic mean of the average misorientation of the IPF001 image m1, the average misorientation of the IPF010 image m2, and the average misorientation of the IPF100 image m3. Since there are three planes or axes, there are three angles at each point, and the smallest angle among these is evaluated. If the three-direction average misorientation measured as above is 15.6° or less, the easy axis of magnetization is aligned in the three directions. <100> is judged to be complete.

[0056] The EBSD measurement method and measurement results are summarized in Table 1 and Figures 2 to 5.

[0057] [Table 1]

[0058] 2 to 5 reveal the following: The soft magnetic body of Experimental Example 1 was fabricated by additive manufacturing using a soft magnetic powder material, and had easy axes of magnetization aligned in three directions: a first direction, which is the additive manufacturing direction; a second direction perpendicular to the first direction, which is a direction parallel to the scanning direction of the heat source during additive manufacturing; and a third direction perpendicular to the first and second directions, which is a normal direction perpendicular to the additive manufacturing direction and the scanning direction of the heat source. <100> Therefore, according to the soft magnetic material of Experimental Example 1, magnetic paths can be formed in the above three directions, and the axis of easy magnetization is aligned only in one direction, the rolling direction. <100> It was confirmed that this allows for greater freedom in magnetic circuit design compared to soft magnetic materials such as grain-oriented electromagnetic steel sheets, which have uniform orientations and can only form magnetic paths in one direction.

[0059] Furthermore, the manufacturing method of the soft magnetic body of Experimental Example 1 includes a first step of forming a powder material layer composed of soft magnetic powder material, a second step of preheating the entire powder material layer, and a third step of irradiating an electron beam onto a portion of the preheated powder material layer to be shaped and melting and solidifying the portion irradiated with the electron beam. Therefore, it was confirmed that the manufacturing method of the soft magnetic body of Experimental Example 1 can manufacture the above-mentioned soft magnetic body, which can improve the degree of freedom in magnetic circuit design, without performing rolling.

[0060] Furthermore, according to the results of Experimental Example 1, when manufacturing a soft magnetic material, if the linear energy is 1.5 J / mm or more and the scanning speed is 450 mm / s or more and 750 mm / s or less in the additive manufacturing conditions, the three-direction average orientation difference can be 15.6° or less, and the easy axis of magnetization is closer to the target than when the linear energy is 1.5 J / mm or more and the scanning speed is less than 450 mm / s, or when the linear energy is 1.5 J / mm or more and the scanning speed is more than 750 mm / s. <100> It was confirmed that the electron beam was used as the heat source in Experimental Example 1, but the same results were obtained when a laser beam was used.

[0061] <Experimental Example 2> -Magnetic property evaluation- The soft magnetic material of sample A was produced in the same manner as in Experimental Example 1, except that the above Fe-Si powder was used as the soft magnetic powder material, and the additive manufacturing conditions were as follows: heat source: electron beam, line energy: 2.56 J / mm, scan speed: 650 mm / s, scan pattern: cross-snake, layer thickness: 200 μm, stage heating temperature: 970°C, and model size: a rectangular shape with a length of 15 mm in the additive manufacturing direction, a length of 20 mm in the heat source scanning direction perpendicular to the additive manufacturing direction, and a length of 20 mm in the normal direction perpendicular to the additive manufacturing direction and the heat source scanning direction.

[0062] When EBSD measurement was performed in the same manner as in Experimental Example 1, the soft magnetic material of Sample A had an easy axis of magnetization aligned in three directions: the additive manufacturing direction, the direction parallel to the scanning direction of the heat source during additive manufacturing, and the normal direction perpendicular to the additive manufacturing direction and the scanning direction of the heat source. <100> All were there.

[0063] In addition, the soft magnetic powder material was the above Fe-Si powder, and the soft magnetic material of sample C was produced under the following additive manufacturing conditions: heat source: laser light, line energy: 0.279 J / mm, scan speed: 250 mm / s, scan pattern: cross-snake, layer thickness: 25 μm, stage heating temperature: 200°C, and model size: length in the additive manufacturing direction: 7 mm, length in the heat source scanning direction perpendicular to the additive manufacturing direction: 5 mm, length in the normal direction perpendicular to the additive manufacturing direction and the heat source scanning direction: 5 mm.

[0064] When EBSD measurement was performed in the same manner as in Experimental Example 1, the soft magnetic material of Sample C had an easy axis of magnetization aligned in three directions: the additive manufacturing direction, the direction parallel to the scanning direction of the heat source during additive manufacturing, and the normal direction perpendicular to the additive manufacturing direction and the scanning direction of the heat source. <100> were not all in place.

[0065] From each soft magnetic material sample in the shape of a rectangular bar after additive manufacturing, a square ring-shaped sample for evaluating magnetic properties was cut out with the dimensions (unit: mm) shown in Figure 6. A BH tracer was used as a magnetic property measuring device to measure the magnetic flux density B20, which is the magnetic flux density H at a magnetic field B of 2000 A / m, the coercive force, and the maximum permeability. The results are shown in Figures 7 and 8. Note that the higher the magnetic flux density B20, the lower the coercive force, and the higher the maximum permeability, the better the magnetic properties.

[0066] As shown in Figures 7 and 8, the easy axis of magnetization <100> The soft magnetic material of sample A (corresponding to sample 12 in Experimental Example 1) in which the magnetization easy axis is aligned in three directions <100> Compared to the soft magnetic material of sample C, which is not aligned in three directions, it was confirmed that the magnetic flux density B20 was larger, the coercive force was smaller, the maximum magnetic permeability was larger, and it had high magnetic properties.

[0067] <Experimental Example 3> Among the soft magnetic materials produced in Experimental Example 1, Sample 12, which had the smallest average orientation difference in three directions in the EBSD measurement at the center of the central cross section, was subjected to additional measurement of the crystal orientation of the entire central cross section by EBSD. The additive manufacturing conditions for producing Sample 12 were specifically as follows: energy density: 131.48 J / mm 2 Line energy: 2.56 J / mm, Scan speed: 650 mm / s, Scan pattern: Cross-snake, Layer thickness: 100 μm, Stage heating temperature: 970°C, Build size: Length in the build direction: 17 mm, Length in the heat source scanning direction perpendicular to the build direction: 12 mm, Length in the normal direction perpendicular to the build direction and the heat source scanning direction: 12 mm.

[0068] The results are shown in Figure 9. As shown in Figure 9, the degree of orientation of the crystal orientation is high in the center of the soft magnetic material and the upper part above it, while the degree of orientation of the crystal orientation is lower in the left part, the right part, and the area 3 to 4 mm from the edge of the lower part below the center of the soft magnetic material, and a metal structure close to equiaxed crystals was confirmed. <100> The portions with a low degree of orientation can be removed by cutting, polishing, or the like.

[0069] The present invention is not limited to the above-described embodiments and experimental examples, and various modifications are possible without departing from the spirit of the present invention. Furthermore, the configurations shown in the embodiments and experimental examples can be combined in any manner.

[0070] The features of the present invention are as follows. [1] A soft magnetic body obtained by layered manufacturing using a soft magnetic powder material, The magnetization easy axis is aligned in three directions: a first direction, which is the additive manufacturing direction; a second direction perpendicular to the first direction; and a third direction perpendicular to the first direction and the second direction. <100> are available, Soft magnetic material. [2] The soft magnetic powder material is mainly composed of Fe, [1] The soft magnetic material according to [1]. [3] The soft magnetic powder material contains at least one selected from the group consisting of Si, C, Mn, P, S, Cu, Ni, Cr, Mo, O, Al, Ga, and N. [1] or [2]. [4] The soft magnetic powder material contains 2 mass% or more of Si. [1] to [3]. [5] The soft magnetic powder material contains at least one selected from the group consisting of C, Mn, P, and S. [1] to [4]. A soft magnetic material according to any one of [1] to [4]. [6] A first step of forming a powder material layer made of soft magnetic powder material; a second step of preheating the entire powder material layer; a third step of irradiating an electron beam or laser light onto a portion of the preheated powder material layer to be molded, thereby melting and solidifying the portion irradiated with the electron beam or the laser light; Manufacturing method of soft magnetic material. [7] In the first step, the particle size of the soft magnetic powder material is 200 μm or less. [6] A method for producing a soft magnetic material according to [6]. [8] In the second step, preheating the entire powder material layer by irradiating the entire powder material layer with the electron beam or the laser light, or preheating the entire powder material layer by using a base plate for forming the powder material layer; [6] or [7], a method for producing a soft magnetic material. [9] In the second step, preheating the entire powder material layer using the base plate is performed by irradiating the base plate with the electron beam or the laser light to heat the stage, or by heating the base plate with a heater and then heating the entire powder material layer with the heated base plate; [8] A method for producing a soft magnetic material according to the present invention.

[10] In the second step, The preheating temperature is 600°C or higher. A method for producing a soft magnetic material according to any one of [6] to [9].

[11] In the third step, The electron beam or the laser light is irradiated under conditions that satisfy a linear energy of 1.5 J / mm or more. A method for producing a soft magnetic material according to any one of [6] to

[10] .

[12] In the third step, The electron beam or the laser light is irradiated under a condition that a scanning speed is 450 mm / s or more and 750 mm / s or less. A method for producing a soft magnetic material according to any one of [6] to

[11] .

[13] In the third step, the scanning pattern of the electron beam or the laser light is a snake scan; [6] to

[12] . A method for producing a soft magnetic material according to any one of [6] to

[12] .

[14] The soft magnetic powder material is mainly composed of Fe, A method for producing a soft magnetic material according to any one of [6] to

[13] .

[15] The soft magnetic powder material contains at least one selected from the group consisting of Si, C, Mn, P, S, Cu, Ni, Cr, Mo, O, Al, Ga, and N. A method for producing a soft magnetic material according to any one of [6] to

[14] .

[16] The soft magnetic powder material contains 2 mass% or more of Si. [6] to

[15] . A method for producing a soft magnetic material according to any one of [6] to

[15] .

[17] The soft magnetic powder material contains at least one selected from the group consisting of C, Mn, P, and S.

[16] A method for producing a soft magnetic material according to any one of [6] to

[16] .

[18] a fourth step of preheating again the powder material layer after the third step has been irradiated with the electron beam or the laser light and melted and solidified, [6] to

[17] . A method for producing a soft magnetic material according to any one of [6] to

[17] .

Claims

1. A soft magnetic body obtained by layered manufacturing using a soft magnetic powder material, The easy axis of magnetization <100> is aligned in three directions: a first direction, which is the additive manufacturing direction; a second direction perpendicular to the first direction; and a third direction perpendicular to the first direction and the second direction. Soft magnetic material.

2. The soft magnetic powder material is mainly composed of Fe, The soft magnetic material according to claim 1 .

3. The soft magnetic powder material contains at least one selected from the group consisting of Si, C, Mn, P, S, Cu, Ni, Cr, Mo, O, Al, Ga, and N. The soft magnetic material according to claim 2 .

4. The soft magnetic powder material contains 2 mass% or more of Si. The soft magnetic material according to claim 2 .

5. The soft magnetic powder material contains at least one selected from the group consisting of C, Mn, P, and S. The soft magnetic material according to claim 2 .

6. a first step of forming a powder material layer made of soft magnetic powder material; a second step of preheating the entire powder material layer; a third step of irradiating an electron beam or laser light onto a portion of the preheated powder material layer to be molded, thereby melting and solidifying the portion irradiated with the electron beam or the laser light; Manufacturing method of soft magnetic material.

7. In the first step, the particle size of the soft magnetic powder material is 200 μm or less. The method for producing the soft magnetic material according to claim 6 .

8. In the second step, preheating the entire powder material layer by irradiating the entire powder material layer with the electron beam or the laser light, or preheating the entire powder material layer by using a base plate for forming the powder material layer; The method for producing the soft magnetic material according to claim 6 .

9. In the second step, preheating the entire powder material layer using the base plate is performed by irradiating the base plate with the electron beam or the laser light to heat the stage, or by heating the base plate with a heater and then heating the entire powder material layer with the heated base plate; The method for producing the soft magnetic material according to claim 8.

10. In the second step, The preheating temperature is 600°C or higher. The method for producing the soft magnetic body according to any one of claims 6 to 9.

11. In the third step, The electron beam or the laser light is irradiated under conditions that satisfy a linear energy of 1.5 J / mm or more. The method for producing the soft magnetic body according to any one of claims 6 to 9.

12. In the third step, The electron beam or the laser light is irradiated under a condition that a scanning speed is 450 mm / s or more and 750 mm / s or less. The method for producing the soft magnetic material according to claim 11.

13. In the third step, the scanning pattern of the electron beam or the laser light is a snake scan; The method for producing the soft magnetic body according to any one of claims 6 to 9.

14. The soft magnetic powder material is mainly composed of Fe, The method for producing the soft magnetic body according to any one of claims 6 to 9.

15. The soft magnetic powder material contains at least one selected from the group consisting of Si, C, Mn, P, S, Cu, Ni, Cr, Mo, O, Al, Ga, and N. The method for producing the soft magnetic material according to claim 14.

16. The soft magnetic powder material contains 2 mass% or more of Si. The method for producing the soft magnetic material according to claim 14.

17. The soft magnetic powder material contains at least one selected from the group consisting of C, Mn, P, and S. The method for producing the soft magnetic material according to claim 14.

18. a fourth step of preheating again the powder material layer after the third step has been irradiated with the electron beam or the laser light to melt and solidify it, The method for producing the soft magnetic body according to any one of claims 6 to 9.

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