Magnetic wire and method for manufacturing magnetic wire

Abstract

To provide a soft magnetic material which has excellent magnetic properties such as permeability without extremely thinning the thickness of a material and hardly causes saturation of magnetization even under high magnetic fields and to provide a method for manufacturing such a soft magnetic material.SOLUTION: There is provided a magnetic wire which is formed as a wire made of an alloy comprising 40 mass% or more and 50 mass% or less of Ni and the balance Fe with inevitable impurities, where in a cross-section along an axial direction of the wire, the ratio of the crystalline structure where the angular difference between the axial direction and a <111> direction is within 10 degrees is 20% or more. In addition, there is provided a method for manufacturing the magnetic wire which conducts a wire drawing step of drawing an alloy material composed of 40 mass% or more and 50 mass% or less of Ni and the balance Fe with inevitable impurities to obtain the wire and a heat treatment step of applying a heat treatment to the wire obtained in the wire drawing step. When the area reduction rate in the wire drawing step is defined as Red (%) and the wire diameter of the wire after wire drawing is defined as φ (mm), Redφ is set to 49 or more.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a magnetic wire and a method for manufacturing the same, and more particularly to a magnetic wire made of permalloy and having a controlled texture, and a method for manufacturing the same. [Background technology]

[0002] Permalloys, including Permalloy PE, are soft magnetic materials that can achieve high magnetic flux density and high magnetic permeability, and are therefore widely used as materials for the magnetic cores and yokes mounted in various devices such as sensors. In particular, as described in Patent Document 1 and the like, the magnetic properties of the strip material can be improved by controlling the texture. For example, when manufacturing Permalloy PE strips, the strips are cold worked at a rolling reduction of 95% or more, and then heat treated at a temperature of 1000°C or higher, thereby improving the magnetic properties of the strips along the easy axis of magnetization. <100> A recrystallized texture oriented in the rolling direction can be obtained. The resulting Permalloy PE band tends to have a high squareness ratio of 90% or more in the demagnetization curve, making it suitable for use as a core material for saturable transformers in the form of a toroidal wound core or laminated core. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 7-98975 Summary of the Invention [Problem to be solved by the invention]

[0004] As described above, to impart excellent magnetic properties, such as a squareness ratio of 90% or more, to a permalloy strip, cold working must be performed at a high reduction rate, such as a reduction rate of 95% or more, resulting in a small thickness of the resulting strip. Consequently, to manufacture products requiring a certain thickness, it becomes necessary to stack multiple strips. For example, in response to the recent trend toward higher currents in electric vehicles, the core materials of saturable transformers and current sensors installed in automobiles must be able to pass large magnetic fluxes, and laminated cores made of multiple permalloy strips are used. The more strips are stacked, the more complicated the lamination process becomes, thereby increasing product manufacturing costs. Furthermore, the thinner the permalloy strip, the greater the likelihood of eddy current loss. For example, with the recent spread of wireless power transfer systems, there has been an increasing demand for soft magnetic back yokes placed on the back side of power receiving coils to improve power transfer efficiency, and permalloy strips are also used for this purpose. However, because power supply systems operate at high frequencies such as 85 kHz, eddy current loss in the permalloy strip and the resulting heat generation can be problematic. While processing permalloy strips at high reduction rates improves magnetic properties such as magnetic flux density and squareness ratio, the resulting thinning of the strip necessitates the need for multi-layer lamination and increases eddy current loss. Therefore, there is a need to develop soft magnetic materials that can exhibit high magnetic properties without excessively reducing the thickness of the material.

[0005] Furthermore, in the permalloy strip, the easy axis of magnetization <100> The direction of the easy axis of magnetization is easily aligned in the rolling direction. This is the factor that gives permalloy strip material high magnetic properties such as high magnetic flux density and high magnetic permeability. On the other hand, because the easy axis of magnetization is aligned in the rolling direction, magnetization is easily saturated in low magnetic fields. Therefore, it is difficult to use permalloy strips in applications where it is desired that the soft magnetic material does not easily become saturated with magnetization even in high magnetic fields, such as large current sensors. If a soft magnetic material that does not easily become saturated with magnetization even in high magnetic fields could be obtained, it could be used preferably in applications where such high magnetic fields occur.

[0006] The problem to be solved by the present invention is to provide a soft magnetic material that has excellent magnetic properties such as magnetic permeability and is resistant to magnetization saturation even in a high magnetic field, without making the material extremely thin, and to provide a method for manufacturing such a soft magnetic material. [Means for solving the problem]

[0007] As a soft magnetic material and a method for manufacturing a soft magnetic material for solving the above problems, a magnetic wire and a method for manufacturing a magnetic wire according to the present invention have the following configurations. [1] The magnetic wire according to the present invention is configured as a wire of an alloy containing 40 mass % or more and 50 mass % or less of Ni, the remainder being Fe and unavoidable impurities, and in a cross section along the axial direction of the wire, <111> The proportion of crystal structures with an angular difference between directions of 10° or less is 20% or more.

[0008] [2] In the above aspect [1], the magnetic wire may further contain 0.3 mass % or more and 0.7 mass % or less of Mn.

[0009] [3] In the above aspect [1] or [2], the wire diameter of the magnetic wire may be 0.1 mm or more and 30 mm or less.

[0010] The method for producing a soft magnetic material according to the present invention has the following configuration. [4] The method for manufacturing magnetic wire according to the present invention includes a wiredrawing step in which an alloy material containing 40% by mass or more and 50% by mass or less of Ni, with the remainder being Fe and unavoidable impurities, is drawn to obtain wire, and a heat treatment step in which the wire obtained in the wiredrawing step is heat-treated, in which Red·φ is 49 or more, where Red (%) is the area reduction rate in the wiredrawing step and φ (mm) is the wire diameter of the wire after wiredrawing.

[0011] [5] In the above aspect [4], the alloy material may further contain 0.3 mass % or more and 0.7 mass % or less of Mn.

[0012] [6] In the aspect [4] or [5] above, in the wire drawing step, the wire diameter φ of the wire may be set to 0.1 mm or more and 30 mm or less.

[0013] [7] In any one of the above aspects [4] to [6], in the wire drawing step, the area reduction rate Red may be set to 85% or more.

[0014] [8] In any one of the above aspects [4] to [7], the wire may be heated at a temperature of 700° C. or higher in the heat treatment step. [Effects of the Invention]

[0015] The magnetic wire of the present invention having the configuration [1] above has a component composition similar to that of permalloy PE and provides high magnetic flux density and high magnetic permeability. When permalloy material is processed into a wire having a predetermined diameter, it can be processed by wiredrawing, which allows for control of the crystal texture. By converting permalloy material into a wire, texture control can be achieved without excessively reducing dimensions in a specific direction, such as the thickness of a strip. Furthermore, when forming a strip by rolling, the reduction occurs in only one direction, whereas when drawing a wire, the reduction in wire diameter progresses two-dimensionally. Therefore, it is easier to increase the degree of processing with wire than with strip, and texture control through processing and the resulting improvement of magnetic properties such as squareness ratio can be effectively achieved.

[0016] Furthermore, the inventors' research has revealed that when manufacturing a wire by drawing and heat treating a permalloy material having the above-mentioned composition, it is possible to control the crystal orientation along the drawing direction (axial direction) by adjusting the conditions during the wiredrawing. The area reduction rate during the wiredrawing process is Red (%), and the wire diameter of the wire after drawing is φ (mm), and by increasing Red·φ, the hard magnetization axis, which is the direction of the crystal orientation along the axial direction, can be controlled. <111> This makes it easier to orient the crystal structure in the direction of the axis of the wire. <111> This allows the formation of a state in which the proportion of crystal structures with an angular difference between directions of 10° or less is as large as 20% or more. As a result, when a magnetic field is applied along the axial direction of the wire, magnetization saturation is less likely to occur.

[0017] In this way, a permalloy material having a predetermined composition is used as a wire material, and <111> By ensuring a high proportion of the crystalline structure oriented in the axial direction of the wire, it is possible to obtain a soft magnetic material with excellent magnetic properties and resistance to magnetization saturation without excessively reducing the thickness of the material. This magnetic wire can be used as a core material that can handle large currents and a yoke material that suppresses eddy current loss, without the need for multi-layer lamination of the material.

[0018] In the above aspect [2], the magnetic wire contains a predetermined amount of Mn. Mn improves the workability of the permalloy material during wire drawing, and by including Mn in the wire in the predetermined amount, it becomes easier to draw the wire at a high area reduction rate while maintaining high magnetic properties.

[0019] In the above aspect [3], the wire diameter of the magnetic wire is 0.1 mm or more and 30 mm or less, which makes it possible to obtain a wire that has excellent magnetic properties and is highly effective in suppressing magnetic field saturation in a high magnetic field.

[0020] The method for producing a soft magnetic material according to the present invention has the following configuration. In the method for manufacturing a magnetic wire rod according to the present invention having the above-mentioned configuration [4], a permalloy alloy material having a predetermined composition is wiredrawn with Red·φ set to 49 or more, and then heat-treated. <111> It is possible to efficiently manufacture magnetic wire in which the proportion of crystalline structures with an angle difference between directions of 10° or less is 20% or more. The obtained wire does not have extremely small dimensions in a specific direction, unlike a ribbon material, and the hard axis of magnetization is not large. <111> By ensuring a large proportion of the crystal structure oriented in the axial direction of the wire, saturation of magnetization is unlikely to occur even in a high magnetic field.

[0021] In the above aspect [5], the alloy material contains a predetermined amount of Mn, so that the magnetic properties of the obtained wire can be maintained at a high level, and the workability in the wire drawing step can be improved.

[0022] In the above aspect [6], the wire diameter φ of the resulting wire is set to 0.1 mm or more and 30 mm or less in the wiredrawing step, thereby making it possible to produce a wire that has excellent magnetic properties and is highly effective in suppressing magnetic field saturation in a high magnetic field.

[0023] In the above aspect [7], in the wire drawing step, the area reduction rate Red is set to 85% or more. Then, in the produced wire rod, <111> This makes it easier to form a state in which a large proportion of the crystal structure has its direction oriented in the axial direction of the wire.

[0024] In the above embodiment [8], the heat treatment step is carried out at a temperature of 700°C or higher. As a result, after recrystallization in the heat treatment step, <111> This makes it easier to manufacture a wire in which the crystal structure with its direction oriented in the axial direction of the wire accounts for a large proportion and which exhibits good soft magnetic properties. [Brief explanation of the drawings]

[0025] [Figure 1] 1 is a diagram showing the frequency distribution of crystal orientation for (a) Example 1, (b) Comparative Example 1, and (c) Comparative Example 2. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0026] A magnetic wire according to an embodiment of the present invention and a method for producing the same will be described in detail below.

[0027] [Magnetic wire] First, a magnetic wire according to one embodiment of the present invention will be described. The magnetic wire according to this embodiment is configured as a wire made of permalloy. Specifically, the magnetic wire is configured as a wire made of an alloy having the following composition. The magnetic wire has a composition classified as permalloy PE or a composition close to that.

[0028] The alloy constituting the magnetic wire contains 40% by mass or more and 50% by mass or less of Ni, with the remainder being Fe and unavoidable impurities. Ni provides high magnetic properties, such as high magnetic flux density and high magnetic permeability, to soft magnetic materials. By making the Ni content 40% by mass or more, a significant improvement in magnetic properties can be obtained. It is more preferable that the Ni content be 45% by mass or more.

[0029] On the other hand, if the soft magnetic material contains too much Ni, the magnetic properties may deteriorate. Furthermore, the material cost of the soft magnetic material increases. To maintain high magnetic properties and reduce material costs, the Ni content is set to 50% by mass or less. A Ni content of 48% by mass or less is more preferable.

[0030] The alloy constituting the magnetic wire may further contain 0.3 mass % or more and 0.7 mass % or less of Mn as an optional element. Mn improves the cold workability of the soft magnetic material. If the alloy constituting the magnetic wire has high cold workability, wire drawing can be performed at a high area reduction rate while avoiding cracking in the wire. As will be explained later, wire drawing at a sufficiently high area reduction rate can effectively control the texture. On the other hand, if the Mn content is too high, magnetic properties such as magnetic flux density will be reduced. If the Mn content is within the above range, the magnetic wire can be significantly improved in cold workability while maintaining high magnetic properties such as magnetic permeability and magnetic flux density.

[0031] The magnetic wire of this embodiment has a crystalline structure along the axial direction (longitudinal direction) of the wire. <111> Specifically, in a cross section along the axial direction of the magnetic wire, <111> The degree of orientation is 20% or more. <111> The degree of orientation is the degree of orientation in the axial direction. <111> The difference in angle between the directions is within 10°. <111> It also refers to the percentage of the area occupied by the tissue. <100> The degree of orientation is the degree of orientation in the axial direction. <100> The difference in angle between the directions is within 10°. <100> The distribution of crystal orientation in a wire can be evaluated by electron backscatter diffraction (EBSD). In the results of EBSD measurement of a cross section of a wire cut along its axial direction, the axial direction is used as the reference. <111> Tissues with orientations within 10° <100> All that is required is to estimate the percentage of the area occupied by each tissue that is oriented within 10° of the other.

[0032] In the cubic crystal of Fe-Ni alloy, the easy axis of magnetization is <100> direction, and the hard axis is <111> In the magnetic wire according to this embodiment, the hard axis of magnetization is <111> Because the orientation of the magnetic wire in the axial direction is promoted, saturation of magnetization is unlikely to occur even when a high magnetic field is applied along the axial direction. Therefore, even in a high magnetic field, the magnetic wire can function as a soft magnetic material while maintaining the excellent magnetic properties such as high magnetic permeability that are obtained as a result of the component composition of the magnetic wire. <111> Compared to the organization, <100> The structure is more stable in terms of surface energy, and thermodynamically, <100> The organization, <111> However, as will be described later, by controlling the conditions in the wire drawing process when manufacturing magnetic wire, <111> The degree of orientation can be increased. <111> If the degree of orientation is increased to 20% or more, the effect of suppressing saturation of magnetization in a high magnetic field environment can be significantly achieved. <111> It is more preferable that the degree of orientation is 40% or more. <111> The higher the degree of orientation, the greater the effect of suppressing magnetization saturation. <111> There is no particular upper limit to the degree of orientation, but it is practically easy to achieve. <111> The degree of orientation is generally 80% or less.

[0033] In a cross section along the axial direction of the magnetic wire, <111> If the degree of orientation is 20% or more, <100> The relationship with the degree of orientation is not particularly limited, but <111> From the viewpoint of enhancing the effect of suppressing saturation of magnetization by tissue, <100> A lower degree of orientation is preferred. For example, <100> It is preferable that the degree of orientation is suppressed to less than 30%, further less than 25%, or even less than 20%. <111> The degree of orientation is <100> The degree of orientation is preferably 90% or more, and more preferably 95% or more. <111> The degree of orientation is <100> It is preferable that the degree of orientation is larger than the degree of orientation.

[0034] The wire diameter of the magnetic wire according to this embodiment is not particularly specified, but is preferably 0.1 mm or more. By preventing the wire diameter of the magnetic wire from being excessively small, the volume of the magnetic wire can be sufficiently secured, and the magnetic properties of the magnetic wire as a soft magnetic material can be easily exhibited. Furthermore, if the wire diameter is large, the specific surface area becomes small, which makes the magnetic wire unstable in terms of surface energy. <111> This makes it easier to maintain the structure. It is also suitable for practical use as a core material or yoke material. It is more preferable if the wire diameter is 0.3 mm or more. On the other hand, it is preferable to keep the wire diameter of the magnetic wire material to 30 mm or less. By controlling the wire drawing process under these conditions, <111> A magnetic wire having a highly oriented texture can be obtained, which is highly effective in suppressing saturation in a high magnetic field.The wire diameter is preferably 10 mm or less, and more preferably 5 mm or less.

[0035] The magnetic wire according to this embodiment has excellent magnetic properties such as high magnetic flux density, high magnetic permeability, and high squareness ratio due to the effect of the component composition and the effect of texture control during processing into the wire, and can be suitably used as a material for forming soft magnetic members such as magnetic cores and yokes. <111> Because of the high degree of orientation, magnetization saturation is unlikely to occur even when a high magnetic field is applied, and excellent magnetic properties such as high magnetic permeability can be maintained. Utilizing this, the magnetic wire according to this embodiment can be particularly suitably used in applications where a high magnetic field is generated, such as the core material of a current sensor for large currents. The magnetic wire can be incorporated into various devices such as sensors, with the axial direction of the magnetic wire oriented in the direction in which the magnetic field is applied.

[0036] Conventionally, texture control has generally been achieved by forming permalloy into a strip and rolling it at a high reduction rate. However, by forming it into a wire, as in the magnetic wire of this embodiment, texture control through processing can be achieved without extremely reducing the dimension in a specific direction, such as the thickness direction of the strip. While a strip requires a process of stacking multiple pieces to ensure the thickness of the material (core), a wire can ensure the thickness without stacking, thereby reducing the process and cost required for stacking. When a large volume of material needs to be secured, multiple wires can be appropriately bundled together, which is easier to perform than stacking. In addition, since the thickness of the wire is not made extremely thin, eddy current loss and the associated heat generation, which are likely to be a problem in thin strips, are minimized. Therefore, the wire of this embodiment can be suitably used in applications where heat generation due to eddy current loss is likely to be a problem, such as the back yoke of a wireless power transfer system, which is used in high frequencies. In the case of strip material, reduction is performed in one direction during manufacturing, whereas in the case of wire material, the diameter is reduced by applying a force two-dimensionally from the entire outer periphery toward the center during the wire drawing process. This makes it easier to increase the degree of processing compared to strip material, and as a result, it is possible to control the texture through processing, that is, to reduce the diameter in the axial direction. <111> Furthermore, the wire has the advantage that it can be placed in places where a strip cannot be placed, such as inside a pipe.

[0037] [Magnetic wire manufacturing method] Next, a method for manufacturing a magnetic wire according to one embodiment of the present invention will be described. By using the manufacturing method according to this embodiment, the magnetic wire according to the embodiment of the present invention described above can be suitably manufactured. In the manufacturing method according to this embodiment, the magnetic wire is manufactured by carrying out a wire drawing step and a heat treatment step in this order.

[0038] In the wiredrawing process, an alloy material having a predetermined composition is drawn and reduced in diameter to be processed into a wire having a predetermined diameter. The alloy material used in the wiredrawing process has the same composition as the magnetic wire material according to the embodiment of the present disclosure described above. That is, an alloy material containing 40% by mass to 50% by mass of Ni, with the remainder being Fe and unavoidable impurities, is used. Alternatively, the alloy material may further contain 0.3% by mass to 0.7% by mass of Mn. After producing an alloy material having a predetermined composition through melting and casting, the wiredrawing process can be performed, with hot treatments interposed between them as needed. For example, a wire having a predetermined diameter and area reduction can be produced by repeatedly drawing with an area reduction of 70% or more and heat treatment at 700°C or higher.

[0039] In the wiredrawing process, the processing conditions are defined by the area reduction rate Red (%) and the wire diameter φ (mm) of the wire after wiredrawing. The area reduction rate Red indicates the reduction in the cross-sectional area of ​​the wire due to wiredrawing, expressed as a ratio based on the cross-sectional area before wiredrawing. In the manufacturing method according to this embodiment, wiredrawing is performed so that the product Red·φ of the area reduction rate Red and the wire diameter φ after wiredrawing is 49 or more. By performing wiredrawing under these conditions, after the next heat treatment process, the following can be achieved: <111> This makes it easier to obtain a magnetic material according to an embodiment of the present disclosure with an orientation degree of 20% or more.

[0040] The wire drawing process allows the crystalline structure in the wire to be oriented in a certain direction, and the higher the area reduction rate, the more the crystalline structure orientation can be improved. <100> rather than direction <111> Therefore, the higher the reduction in area, the more the magnetic wire rod becomes oriented in the direction of drawing (i.e., the axial direction). <111> On the other hand, as mentioned above, in terms of surface energy, <111> than the organization <100> The structure is more stable, and the smaller the wire diameter and the larger the specific surface area, <100> In other words, it is better to make the wire diameter larger after drawing. <111> In this way, due to the two factors, the larger the product Red·φ of the area reduction rate and the wire diameter after drawing, <111> As will be shown in the examples below, if Red·φ is set to 49 or more, the following can be obtained in the cross section along the axial direction: <111> This method allows for the production of magnetic wire with an orientation degree of 20% or more. Red·φ is preferably 60 or more, and even more preferably 80 or more. Since a larger Red·φ is more preferable, there is no particular upper limit, but Red·φ that can be achieved in actual wiredrawing operations is generally 95 or less. Wiredrawing can be performed as cold working, such as at room temperature.

[0041] As long as the product of the area reduction rate and the wire diameter after drawing, Red·φ, is 49 or more, the individual values ​​of the area reduction rate Red and φ are not particularly limited. However, if the area reduction rate is set to 85% or more, or even 90% or more, or 95% or more, <111> This is highly effective in improving the degree of orientation. The higher the area reduction rate, the better, and there is no particular upper limit. As explained above for the magnetic wire, the wire diameter is preferably 0.1 mm or more and 30 mm or less.

[0042] In the heat treatment process, the drawn wire is subjected to heat treatment (magnetic annealing). The heating conditions in the heat treatment process are not particularly limited and may be appropriately determined so as to fully achieve the purpose of magnetic annealing, i.e., to fully achieve the removal of processing strain and the accompanying improvement of soft magnetic properties, including a reduction in coercive force. For example, the heating temperature is preferably 700°C or higher, and even more preferably 1000°C or higher. It is also preferable to keep the heating temperature at 1200°C or lower. The heating time can be, for example, in the range of 30 minutes to 180 minutes. The atmosphere during the heat treatment can be hydrogen, etc. [Example]

[0043] The present invention will be described in more detail below using examples, but the present invention is not limited to these examples.

[0044] [Sample preparation] Wires according to Examples 1 to 5 and Comparative Examples 1 to 8 were produced. That is, alloy materials containing the amounts of Ni (and Mn) shown in Table 1, with the balance being Fe and unavoidable impurities, were melted and cast. Then, except for Comparative Examples 4 and 5, wire drawing with an area reduction of 70% or more and heat treatment at 700°C or higher were repeated to obtain wires with the wire diameters and area reductions shown in the table. Then, each of the obtained wires was heat treated at 1100°C for 1 hour in a hydrogen atmosphere.

[0045] [Test method] For each sample, electron backscatter diffraction (EBSD) measurements were performed on cross-sectional samples cut along the axial direction. In the EBSD measurements, the observation range was set so that there were 100 or more crystal grains within the field of view. In the results of the EBSD measurements, for multiple measurement points (electron beam spots), <111> The frequency distribution of the crystal orientation was obtained by measuring the angle between the crystal orientation and the direction, and taking the distribution of the angle. The frequency distribution was then integrated over the angle range from 0° to 10°, and the value obtained was: <111> The degree of orientation was also <100> Orientation and <111> Since the angle between the directions is approximately 55°, the value obtained by integrating the frequency distribution obtained in the area from 45° to 55° is: <100> The degree of orientation was determined.

[0046] [Test Results] Table 1 shows the Ni and Mn contents and wire drawing conditions for Examples 1 to 5 and Comparative Examples 1 to 8, as well as the EBSD data obtained. <111> Orientation and <100> The degree of orientation is shown. Figure 1 also shows the frequency distribution of the crystal orientation for (a) Example 1, (b) Comparative Example 1, and (c) Comparative Example 2 as representative examples. Each figure also shows the frequency distribution for the state before heat treatment.

[0047] [Table 1]

[0048] According to the frequency distribution of the crystal orientation of Example 1 (after heat treatment) in FIG. 1(a), <111> In the region where the angle difference with the direction is small, the abundance ratio of the crystalline structure is distributed in a concentrated manner, like a peak that rises sharply from an angle of 0°. <111> It can be seen that the formation of the structure is promoted. The integral of the abundance ratio in the range of 0° to 10° is shown in Table 1. <111> The degree of orientation is 48.7%, which is obtained by integrating the proportion of the molecules in the range of 45° to 55°. <100> This is a significantly larger value than the degree of orientation.

[0049] On the other hand, according to the frequency distribution of the crystal orientations of Comparative Examples 1 and 2 (after heat treatment) in Fig. 1(b) and (c), <111> The proportion of crystalline structures is concentrated in the region where the angle difference with the direction is large (generally 40° or more). A peak-like distribution is also seen in the region where the angle is 20° or less, which can be associated with (100) twins. <100> As shown in Table 1, in both Comparative Examples 1 and 2, <100> The value of the degree of orientation is <111> It is significantly larger than the degree of orientation.

[0050] Similarly, for each data other than the crystal orientation frequency distribution shown in Figure 1, <111> Orientation and <100> The estimated degree of orientation is shown in Table 1. According to this, among Examples 1 to 5 and Comparative Examples 1 to 5 and 8 in which the Ni content is in the range of 40 mass % or more and 50 mass % or less, in Examples 1 to 5, <111> The degree of orientation is 20% or more, <111> It can be seen that the generation of the microstructure is promoted. In Examples 1 to 5, wire drawing was performed under the condition that Red·φ was 49 or more. On the other hand, in all of Comparative Examples 1 to 5 and 8, <111> The degree of orientation did not reach 20%. In particular, in Comparative Examples 1 to 3 and 8, <100> These comparative examples 1 to 5 and 8 were wiredrawn under the condition that Red·φ was less than 49. From these results, it can be seen that the orientation of the crystalline structure can be controlled by the condition during wiredrawing, Red·φ, which is the product of the area reduction rate and the wire diameter after wiredrawing, and by increasing this value, the orientation of the crystalline structure can be controlled. <111> It can be seen that the orientation of the direction of the wire in the axial direction can be promoted. The area reduction rate Red and the wire diameter φ can be individually <111> Orientation degree and <100> There is no significant correlation between the degree of orientation and the crystal orientation.

[0051] Here, in each frequency distribution shown in FIG. 1, when the state before the heat treatment is also looked at, in both Example 1 (a) and Comparative Examples 1 and 2 (b) and (c), before the heat treatment, <111> The proportion of the particles is concentrated in the area where the angle difference with the axial direction is small. <100> Rather than directional orientation, <111> On the other hand, after the heat treatment, the frequency distribution does not change significantly in Example 1 (a), whereas the frequency distribution changes significantly in Comparative Examples 1 and 2 (b) and (c). In other words, as already explained, in (a), <111> The state where the orientation of the direction is high is maintained, whereas in (b) and (c), <100> The orientation of the direction has changed to a higher state. <100> The organization <111> This can be interpreted as being due to the fact that the wire diameter is relatively large at 1.0 mm and the specific surface area is small in Example 1 (a), <111> The state in which the orientation was dominant was maintained even after heat treatment, whereas in Comparative Examples 1 and 2, which had small wire diameters of 0.3 mm and 0.1 mm and large specific surface areas (b) and (c), the heat treatment resulted in a thermodynamically stable <100> It is thought that the transition occurred to a state where the orientation became dominant. <111> To obtain a highly oriented texture, wire drawing is required. <111> The reduction in area must be sufficient to increase the orientation in the direction, and the wire diameter must not be too thin. <100> It can be said that it is effective to increase the value of the product Red·φ, which is the area reduction rate and the wire diameter, so that the change in orientation in the direction can be sufficiently suppressed.

[0052] Examples 1 to 5 and Comparative Examples 1 to 3 and 8 were subjected to wire drawing at a high area reduction rate of 80% or more and heat treatment, respectively. <111> Direction and <100> In contrast to the examples 1 to 5 and the comparative examples 1 to 3 and 8, the reduction in area during wire drawing is low at 50% or less, and Red·φ remains at a small value of 25 or less. In these comparative examples 4 and 5, unlike the examples 1 to 5 and the comparative examples 1 to 3 and 8, <111> Orientation and <100> In both cases, the degree of orientation was a small value below 20%. In Comparative Examples 4 and 5, the low degree of processing during wiredrawing precluded sufficient control of the texture, and it is believed that the orientation of the crystal texture in a specific direction did not occur effectively.

[0053] In Comparative Examples 6 and 7, the Ni content is outside the range of 40 mass% or more and 50 mass% or less. In Comparative Examples 6 and 7, the wire diameter φ and the area reduction rate Red are the same as in Example 1, but compared to Example 1, <111> This shows that the composition of the alloy also affects the orientation of the crystal structure.

[0054] The embodiments and examples of the present invention have been described above. The present invention is not particularly limited to these embodiments and examples, and various modifications can be made.

Claims

1. The wire is made of an alloy containing 40% by mass or more and 50% by mass or less of Ni, with the remainder being Fe and unavoidable impurities, A magnetic wire in which, in a cross section along the axial direction of the wire, the proportion of crystalline structures in which the angular difference between the axial direction and the <111> direction is within 10° is 20% or more.

2. The magnetic wire according to claim 1 , further containing 0.3 mass % to 0.7 mass % of Mn.

3. 3. The magnetic wire according to claim 1, wherein the wire diameter is 0.1 mm or more and 30 mm or less.

4. a wiredrawing step of drawing an alloy material containing 40% by mass or more and 50% by mass or less of Ni, with the remainder being Fe and unavoidable impurities, to obtain a wire; a heat treatment step of performing heat treatment on the wire obtained in the wiredrawing step, A method for manufacturing a magnetic wire, wherein Red·φ is 49 or more, where Red (%) is the area reduction rate in the wiredrawing step and φ (mm) is the wire diameter of the wire after wiredrawing.

5. The method for manufacturing a magnetic wire according to claim 4 , wherein the alloy material further contains 0.3 mass % to 0.7 mass % of Mn.

6. 6. The method for producing a magnetic wire according to claim 4, wherein in the wire drawing step, the wire diameter φ of the wire is set to 0.1 mm or more and 30 mm or less.

7. 6. The method for producing a magnetic wire according to claim 4, wherein the area reduction rate Red in the wire drawing step is set to 85% or more.

8. The method for manufacturing a magnetic wire according to claim 4 or 5, wherein the wire is heated at a temperature of 700° C. or higher in the heat treatment step.

Images