alloy

Abstract

An alloy comprising a noncrystalline phase 16, wherein the average Fe concentration of the alloy overall is 82.0-88.0 at. %, the average Cu concentration of the alloy overall is 0.4-1.0 at. %, the average P concentration of the alloy overall is 5.0-9.0 at. %, the average B concentration of the alloy overall is 6.0-10.0 at. %, the average Si concentration of the alloy overall is 0.4-1.9 at. %, the average C concentration of the alloy overall is 0-2.0 at. %, the average impurity concentration of impurities other than Fe, Cu, P, B, Si, and C in the alloy overall is 0-0.3 at. %, and the total of the average Fe concentration, the average Cu concentration, the average P concentration, the average B concentration, the average Si concentration, the average C concentration, and the average impurity concentration is 100.0 at. %.　

Description

[Technical Field]

[0001] The present invention relates to alloys, for example alloys containing Fe. [Background technology]

[0002] A nanocrystalline alloy has multiple nano-sized crystalline phases formed within an amorphous phase, and an Fe-Cu-PB-Si alloy with a high saturation magnetic flux density and low coercive force is known as such a nanocrystalline alloy (for example, Patent Documents 1 to 5). Such nanocrystalline alloys are used as soft magnetic materials with a high saturation magnetic flux density and low coercive force. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2010 / 021130 [Patent Document 2] International Publication No. 2017 / 006868 [Patent Document 3] International Publication No. 2011 / 122589 [Patent Document 4] Japanese Patent Application Laid-Open No. 2011-256453 [Patent Document 5] Japanese Patent Application Laid-Open No. 2013-185162 Summary of the Invention [Problem to be solved by the invention]

[0004] The crystalline phase is an iron alloy that mainly has a body-centered cubic (BCC) structure, and a small grain size of the crystalline phase improves soft magnetic properties such as coercivity. However, there is a demand for further improvement in the soft magnetic properties of nanocrystalline alloys. Even if the soft magnetic properties are improved, manufacturing difficulties can increase production costs.

[0005] The present invention has been made in view of the above problems, and has an object to provide an amorphous alloy and a nanocrystalline alloy that can be easily produced. [Means for solving the problem]

[0006] The present invention provides an alloy having an amorphous phase, in which the average Fe concentration in the entire alloy is 82.0 atomic % or more and 88.0 atomic % or less, and the average Cu concentration in the entire alloy is 0. 5 At.% or more and 1.0 atomic % or less, and the average P concentration in the entire alloy is 5. 5 The average B concentration in the entire alloy is 6.0 atomic % or more and 9.0 atomic % or less, the average Si concentration in the entire alloy is 0. 9 % or more and 1.9 atomic % or less, the average C concentration of the entire alloy is 0 atomic % or more and 2.0 atomic % or less, the average impurity concentration of impurities other than Fe, Cu, P, B, Si, and C is 0 atomic % or more and 0.3 atomic % or less, and the sum of the average Fe concentration, the average Cu concentration, the average P concentration, the average B concentration, the average Si concentration, the average C concentration, and the average impurity concentrations is 100.0 atomic %. At the same time, (average B concentration - average Si concentration) is 6.5 atomic % or more and 9.5 atomic % or less. It is an alloy.

[0007] In the above structure, the average Fe concentration is 83.0 atomic % or more and 88.0 atomic % or less, and the average Cu concentration is 0. 5 % or more and 0.9 atomic % or less, and the average P concentration is 5. 5 % or more and 8.0 atomic % or less, the average Si concentration is 0.9 atomic % or more and 1.4 atomic % or less, the average C concentration is 0 atomic % or more and 0.1 atomic % or less, and the average impurity concentration is 0 atomic % or more and 0.1 atomic % or less.

[0011] In the above structure, the amorphous phase may be the only component. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide alloys that are easy to manufacture, such as amorphous alloys and nanocrystalline alloys. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a schematic diagram showing the change in temperature with time in the heat treatment for forming a nanocrystalline alloy. [Figure 2] FIG. 2 is a cross-sectional schematic diagram of a nanocrystalline alloy. DETAILED DESCRIPTION OF THE INVENTION

[0014] This section describes the manufacturing methods for amorphous alloys and nanocrystalline alloys. First, an amorphous alloy (precursor alloy) is formed by rapidly cooling the liquid metal obtained by melting a mixture of materials. An amorphous alloy is almost entirely amorphous and contains almost no crystalline phase. In other words, an amorphous alloy consists only of the amorphous phase. Depending on the conditions for rapidly cooling the liquid metal, an amorphous alloy may contain a small amount of crystalline phase. The temperature at which a liquid phase begins to form from the molten metal (liquidus temperature) is designated TL. Next, the amorphous alloy is heat-treated.

[0015] FIG. 1 is a schematic diagram showing the temperature change over time during a heat treatment to form a nanocrystalline alloy (a schematic diagram of the temperature history of the heat treatment). As shown in FIG. 1, at time t1, the material is an amorphous alloy, and the temperature T1 is, for example, 200°C. During the heating period 40 from time t1 to t2, the temperature of the alloy increases from T1 to T2, for example, at an average heating rate 45. The temperature T2 is higher than the temperature at which a crystalline phase (metallic iron crystalline phase) of BCC iron begins to form (slightly lower than the first crystallization onset temperature Tx1) and lower than the temperature at which a crystalline phase (compound crystalline phase) begins to form (slightly lower than the second crystallization onset temperature Tx2). During the holding period 42 from time t2 to t3, the temperature of the alloy remains approximately constant at T2. During the cooling period 44 from time t3 to t4, the temperature of the alloy decreases from T2 to T1, for example, at an average cooling rate 46. In FIG. 1, the heating rate 45 and the cooling rate 46 are constant, but the heating rate 45 and the cooling rate 46 may vary over time.

[0016] Figure 2 is a schematic cross-sectional view of a nanocrystalline alloy. As shown in Figure 2, alloy 10 comprises an amorphous phase 16 and multiple crystalline phases 14 formed within the amorphous phase 16. The crystalline phase 14 is surrounded by the amorphous phase 16. The crystalline phase 14 is primarily an iron alloy with a BCC structure. Alloy 10 contains Fe, Cu, P, B, and Si. C may be intentionally or unintentionally included. Impurity elements other than Fe, Cu, P, B, Si, and C may be unintentionally included. The impurities may be, for example, at least one of Ti, Al, Zr, Hf, Nb, Ta, Mo, W, Cr, V, Co, Ni, Mn, Ag, Zn, Sn, Pb, As, Sb, Bi, S, N, O, and rare earth elements.

[0017] The average Fe, Cu, P, B, Si, C, and impurity concentrations in the entire alloy are CFe, CCu, CP, CB, CSi, CC, and CI. The total of CFe, CCu, CP, CB, CSi, CC, and CI is 100.0 atomic %. CFe, CCu, CP, CB, CSi, CC, and CI correspond to the chemical compositions of the amorphous alloy and nanocrystalline alloy.

[0018] The size (grain size) of the crystalline phase in a nanocrystalline alloy affects soft magnetic properties such as coercivity. A smaller crystalline phase size reduces coercivity and improves soft magnetic properties. Therefore, the average spherical equivalent diameter of the crystalline phase 14 is preferably, for example, 50 nm or less, more preferably 30 nm or less, and even more preferably 20 nm or less. The average spherical equivalent diameter of the crystalline phase 14 is, for example, 5 nm or more. Cu serves as a nucleation site for the formation of the crystalline phase 14. Therefore, nanocrystalline alloys contain Cu. P contributes to making the crystalline phase 14 smaller. B and Si contribute to the formation of the amorphous phase 16. A large amount of P is preferable to make the crystalline phase 14 smaller.

[0019] By controlling the relationship between C, CSi, and C, the size of the crystalline phase 14 can be reduced, lowering the coercivity and improving the soft magnetic properties. Even if the soft magnetic properties are improved, difficulties in manufacturing can lead to problems such as high manufacturing costs. If the second crystallization onset temperature Tx2 is low, it is necessary to control the temperature T2 during the holding period after heating, which can lead to the unintended formation of a compound crystalline phase, making manufacturing difficult. If Tx1 / TL is small, the crystalline phase forms at a lower temperature and in a shorter time when quenching the liquid metal, lowering the temperature at which a healthy amorphous phase forms. As a result, to stably obtain a healthy amorphous alloy, the quenching rate of the liquid metal must be further increased, making stable manufacturing difficult. Thus, to facilitate manufacturing, it is preferable to increase Tx2 and Tx1 / TL.

[0020] However, up until now, no research has been conducted into the more preferable ranges of the concentrations of each element in terms of the relationship between the coercive force and Tx2 and Tx1 / TL. In the following embodiment, by setting the ranges of CSi and CP appropriately, it is possible to reduce the coercive force and make Tx2 and Tx1 / TL appropriate.

[0021] [Embodiment 1] In the first embodiment, the range of each element concentration is limited mainly based on the relationship between the coercive force and Tx2 and Tx1 / TL: CFe is 82.0 atomic % or more and 88.0 atomic % or less, CCu is 0.4 atomic % or more and 1.0 atomic % or less, CP is 5.0 atomic % or more and 9.0 atomic % or less, CB is 6.0 atomic % or more and 10.0 atomic % or less, CSi is 0.4 atomic % or more and 1.9 atomic % or less, CC is 0 atomic % or more and 2.0 atomic % or less, and CI (total amount of impurities) is 0 atomic % or more and 0.3 atomic % or less.

[0022] By making the CFe content 82.0 atomic % or more, the saturation magnetic flux density can be increased. The CFe content is more preferably 83.0 atomic % or more. By increasing the concentration of metalloids (B, P, C, and Si), the amorphous phase 16 can be more stably formed between the crystalline phases 14. For this reason, the CFe content is preferably 88.0 atomic % or less, more preferably 86.0 atomic % or less, and even more preferably 85.0 atomic % or less.

[0023] In the early stages of the formation of the crystalline phase 14, Cu clusters serve as nucleation sites, resulting in the formation of the crystalline phase 14. Therefore, CCu is preferably 0.4 atomic % or more, more preferably 0.5 atomic % or more, and even more preferably 0.6 atomic % or more. The presence of Cu clusters in the crystalline phase 14 and the amorphous phase 16 hinders the movement of domain walls. Furthermore, when Cu dissolves in the crystalline phase 14 and the amorphous phase 16, the quantum mechanical interaction between Fe atoms and Cu atoms increases, resulting in a decrease in the saturation magnetic flux density. From these viewpoints, CCu is preferably 1.0 atomic % or less, more preferably 0.9 atomic % or less, and even more preferably 0.8 atomic % or less.

[0024] If CP is high, the crystalline phase 14 becomes small and the coercive force becomes low. Therefore, CP is preferably 5.0 atomic % or more, more preferably 5.5 atomic % or more, and even more preferably 6.0 atomic % or more. In order to increase CP and make CFe 83.0 atomic % or more, CBr and CSi must be low. If CBr and CSi are too low, it becomes difficult to stably form the amorphous phase 16. Therefore, CP is preferably 9.0 atomic % or less, more preferably 8.5 atomic % or less, and even more preferably 8.0 atomic % or less.

[0025] When C is high, the amorphous phase 16 can be stably formed. Furthermore, as will be understood from the examples described later, if CSi is increased when C is low, Tx1 / TL becomes small, making manufacturing difficult. Therefore, C is preferably 6.0 atomic % or more, more preferably 6.5 atomic % or more, and even more preferably 7.0 atomic % or more. In order to increase C and make CFe 83.0 atomic % or more, C is reduced. If C is too low, the coercivity becomes high. Therefore, C is preferably 10.0 atomic % or less, more preferably 9.5 atomic % or less, and even more preferably 9.0 atomic % or less.

[0026] Increasing CP / CB reduces the size of the crystalline phase 14 and decreases the coercivity. However, increasing CP decreases Tx2, making stable production difficult. Increasing CSi increases Tx2. Therefore, CSi is preferably 0.4 atomic % or more, more preferably 0.6 atomic % or more, and even more preferably 0.9 atomic % or more. In order to increase CSi and make CFe 83.0 atomic % or more, CP must be reduced. If CP is too low, the coercivity increases. Therefore, CSi is preferably 1.9 atomic % or less, more preferably 1.6 atomic % or less, and even more preferably 1.4 atomic % or less.

[0027] From the above viewpoint, in order to optimize the balance between Tx1 / TL, Tx2 and coercive force Hc, it is most preferable that CB-CSi is 6.5 atomic % or more and 9.5 atomic % or less, for example.

[0028] It is preferable that C and impurities are not intentionally added. Therefore, CC is preferably 0 atomic % or more and 2.0 atomic % or less, more preferably 1.0 atomic % or less, and even more preferably 0.1 atomic % or less. CI is preferably 0 atomic % or more and 0.3 atomic % or less, more preferably 0.2 atomic % or less, and even more preferably 0.1 atomic % or less. For each of the impurity elements, it is preferably 0 atomic % or more and 0.10 atomic % or less, and more preferably 0 atomic % or more and 0.02 atomic % or less.

[0029] [Embodiment 2] In the second embodiment, the range of each element concentration is limited mainly by the relationship between coercivity, Tx2, and Tx1 / TL: CFe is 82.0 atomic % or more and 88.0 atomic % or less, CCu is 0.4 atomic % or more and 0.9 atomic % or less, CP is 3.0 atomic % or more and 9.0 atomic % or less, CB is 9.0 atomic % or more and 12.0 atomic % or less, CSi is 1.1 atomic % or more and 4.0 atomic % or less, CC is 0 atomic % or more and 2.0 atomic % or less, and CI (total amount of impurities) is 0 atomic % or more and 0.3 atomic % or less.

[0030] By making the CFe content 82.0 atomic % or more, the saturation magnetic flux density can be increased. The CFe content is more preferably 83.0 atomic % or more. By increasing the concentration of metalloids (B, P, C, and Si), the amorphous phase 16 can be more stably formed between the crystalline phases 14. For this reason, the CFe content is preferably 88.0 atomic % or less, more preferably 86.0 atomic % or less, and even more preferably 85.0 atomic % or less.

[0031] In the early stages of the formation of the crystalline phase 14, Cu clusters serve as nucleation sites, and the crystalline phase 14 is formed. Therefore, CCu is preferably 0.4 atomic % or more, more preferably 0.5 atomic % or more, and even more preferably 0.6 atomic % or more. The presence of Cu clusters in the crystalline phase 14 and the amorphous phase 16 hinders the movement of the domain walls. Furthermore, when Cu dissolves in the crystalline phase 14 and the amorphous phase 16, the quantum mechanical interaction between Fe atoms and Cu atoms increases, which reduces the saturation magnetic flux density. From these perspectives, CCu is preferably 0.9 atomic % or less, and more preferably 0.8 atomic % or less.

[0032] If CP is high, the size of the crystalline phase 14 becomes small and the coercive force becomes low. Therefore, CP is preferably 3.0 atomic % or more, more preferably 3.8 atomic % or more, and even more preferably 4.0 atomic % or more. In order to increase CP and make CFe 83.0 atomic % or more, CBr and CSi must be low. If CBr and CSi are too low, it becomes difficult to stably form the amorphous phase 16. Therefore, CP is preferably 9.0 atomic % or less, more preferably 7.0 atomic % or less, and even more preferably 5.0 atomic % or less.

[0033] When C is high, the amorphous phase 16 can be stably formed. Furthermore, as will be understood from the examples described later, when CSi is high, if C is low, Tx1 / TL becomes small, making manufacturing difficult. Therefore, C is preferably 9.0 atomic % or more, more preferably 9.5 atomic % or more, and even more preferably 10.0 atomic % or more. In order to increase C and make CFe 83.0 atomic % or more, C is reduced. If C is too low, the coercivity increases. Therefore, C is preferably 12.0 atomic % or less, more preferably 11.5 atomic % or less, and even more preferably 11.0 atomic % or less.

[0034] Increasing CP / CB reduces the size of the crystalline phase 14 and the coercive force. However, increasing CP reduces Tx2. Increasing CSi increases Tx2. Therefore, CSi is preferably 1.1 atomic % or more, more preferably 1.3 atomic % or more, and even more preferably 1.5 atomic % or more. In order to increase CSi and make CFe 83.0 atomic % or more, CP must be reduced. If CP is too low, the coercive force increases. Therefore, CSi is preferably 4.0 atomic % or less, more preferably 3.5 atomic % or less, and even more preferably 3.0 atomic % or less.

[0035] From the above viewpoint, in order to optimize the balance between Tx1 / TL, Tx2 and coercive force Hc, it is most preferable that CB-CSi is, for example, 6.5 atomic % or more and 9.5 atomic % or less.

[0036] It is preferable that C and impurities are not intentionally added. Therefore, CC is preferably 0 atomic % or more and 2.0 atomic % or less, more preferably 1.0 atomic % or less, and even more preferably 0.1 atomic % or less. CI is preferably 0 atomic % or more and 0.3 atomic % or less, more preferably 0.2 atomic % or less, and even more preferably 0.1 atomic % or less. For each of the impurity elements, it is preferably 0 atomic % or more and 0.10 atomic % or less, and more preferably 0 atomic % or more and 0.02 atomic % or less.

[0037] [Manufacturing method] A method for producing a nanocrystalline alloy will be described below, but the method for producing an alloy according to the embodiment is not limited to the method described below.

[0038] [Method for manufacturing amorphous alloys] The single roll method is used to produce amorphous alloys. The conditions of the roll diameter and rotation speed for the single roll method are arbitrary. The single roll method is suitable for producing amorphous alloys because it is easy to perform rapid cooling. The cooling rate of the molten alloy to produce amorphous alloys is, for example, 10 4 °C / sec or more is preferable, and 10 6 °C / sec or more is preferable. 4 Methods other than the single roll method, including periods of °C / sec, may also be used. For example, the water atomization method or the atomization method described in Japanese Patent No. 6533352 may be used to produce amorphous alloys.

[0039] [Method of manufacturing nanocrystalline alloys] Nanocrystalline alloys are obtained by heat treatment of amorphous alloys. In the production of nanocrystalline alloys, the temperature history of the heat treatment affects the nanostructure of the nanocrystalline alloy. For example, in the heat treatment shown in Figure 1, the heating rate 45, holding temperature T2, length of holding period 42, and cooling rate 46 mainly affect the nanostructure of the nanocrystalline alloy.

[0040] [Heating rate] A fast heating rate 45 avoids the temperature range where small Cu clusters form, making it easier for many large Cu clusters to form in the early stages of crystallization. This reduces the size of each crystalline phase 14, and facilitates non-equilibrium reactions, increasing the concentrations of P, B, Cu, and other elements in the crystalline phase 14. This increases the total amount of crystalline phase 14 and the saturation magnetic flux density. Furthermore, P and Cu are concentrated in the region near the crystalline phase 14, suppressing the growth of the crystalline phase 14 and reducing its size. This reduces the coercive force. In the temperature range from 200°C to the holding temperature T2, the average heating rate ΔT is preferably 360°C / min or higher, more preferably 400°C / min or higher. It is also preferable that the average heating rate calculated in 10°C increments within this temperature range satisfy the same conditions. However, if it is necessary to dissipate the heat associated with crystallization, such as in a heat treatment after lamination, it is preferable to reduce the average heating rate. For example, such an average heating rate may be 5°C / min or lower.

[0041] To reduce the coercive force, it is preferable that the P concentration (CP) / B concentration (CB) is large. This is thought to be because as the B concentration increases, small Cu clusters are more likely to form. Therefore, to offset the reduction in size of Cu clusters that accompanies the increase in B concentration, the temperature (CP / CB × (ΔT + 20)) calculated using CP / CB and ΔT is preferably 40°C / min or more, more preferably 50°C / min or more, and even more preferably 100°C / min or more. It is even more preferable that (CP / CB × (ΔT + 20)) calculated in 10°C increments within this temperature range also satisfies the same condition.

[0042] [Retention period length] The length of the holding period 42 is preferably a time that allows for determination that crystallization has progressed sufficiently. To determine that crystallization has progressed sufficiently, it is necessary to confirm that a first peak corresponding to the first crystallization onset temperature Tx1 is not observable or has become very small (for example, the heat generation amount is 1 / 100 or less of the total heat generation amount of the first peak in the DSC curve of an amorphous alloy of the same chemical composition) in a curve (DSC curve) obtained by heating the nanocrystalline alloy to about 650°C at a constant heating rate of 40°C / min using differential scanning calorimetry (DSC).

[0043] When crystallization (crystallization at the first peak) approaches 100%, the crystallization rate becomes so slow that it may be impossible to determine whether crystallization has progressed sufficiently using DSC. For this reason, it is preferable to hold the sample for a period longer than expected from the DSC results. For example, a holding period of 0.5 minutes or more is preferable, and 5 minutes or more is more preferable. By achieving sufficient crystallization, the saturation magnetic flux density can be increased. If the holding period is too long, the concentration distribution of solute elements in the amorphous phase may change due to atomic diffusion. For this reason, the holding period is preferably 60 minutes or less, and more preferably 30 minutes or less.

[0044] [Holding temperature] The maximum temperature Tmax of the holding temperature T2 is preferably equal to or higher than the first crystallization onset temperature Tx1-20°C and equal to or lower than the second crystallization onset temperature Tx2-20°C. If Tmax is lower than Tx1-20°C, crystallization does not proceed sufficiently. If Tmax exceeds Tx2-20°C, a compound crystalline phase is formed, resulting in a significant increase in coercivity. The recommended temperature for Tmax is equal to or higher than Tx1+(CB / CP)×5°C and equal to or lower than Tx2-20°C to offset the reduction in Cu cluster size associated with an increase in B concentration. Tmax is more preferably equal to or higher than Tx1+(CB / CP)×5+20°C. Furthermore, Tmax is preferably equal to or higher than the Curie temperature of the amorphous phase 16. Increasing Tmax increases the temperature at which spinodal decomposition begins and increases λm. This reduces the total number of Cu clusters at the initial stage of crystallization while increasing the number of large Cu clusters.

[0045] [Cooling rate] When cooling begins, Cu dissolved in the amorphous phase 16 precipitates. The Cu atoms dissolved in the amorphous phase 16 and the Fe atoms reduce the magnetization of Fe through quantum mechanical interaction. This reduces the saturation magnetic flux density. Therefore, a slow cooling rate 46 is preferable to increase the saturation magnetic flux density. On the other hand, if the cooling rate 46 is too slow, it takes a long time to produce a nanocrystalline alloy. For these reasons, the average cooling rate from when the alloy temperature reaches Tmax or Tx1 + (CB / CP) × 5 to 200°C is preferably 0.2°C / sec or more and 0.5°C / sec or less. From the perspective of maintaining the structure obtained by holding as much as possible and improving production efficiency, the average cooling rate may be, for example, 100°C / min or more.

[0046] [Amorphous alloy] The amorphous alloy used as the precursor alloy of the nanocrystalline alloy in embodiments 1 and 2 is composed of only an amorphous phase. Here, "composed of only an amorphous phase" may include a small amount of crystalline phase as long as the effects of embodiments 1 and 2 can be obtained.

[0047] An example of a method for determining whether an amorphous alloy consists solely of an amorphous phase is described below. This determination is made using a diffraction pattern (e.g., X-ray source: Cu-Kα radiation; 1 step of 0.02°; measurement time per step: 10 seconds) obtained from an X-ray diffractometer (e.g., a Rigaku Smartlab®-9 kW equipped with a counter monochromator): 45 kV, 200 mA). For a ribbon-like or thin-striped sample, if no peaks of iron with a BCC structure are observed in the diffraction pattern of the X-ray diffractometer at the center of the sample's width and a distance of approximately 1 / 8 of the total thickness from the sample's surface, the amorphous alloy is determined to consist solely of an amorphous phase. For a powder-like sample, if the surface is pickled in an inert gas atmosphere until the mass is reduced by at least approximately 0.1% by mass of the weighed sample, and then the sample is dried, the amorphous alloy is determined to consist solely of an amorphous phase if no peaks of iron with a BCC structure are observed in the diffraction pattern of the X-ray diffractometer.

[0048] In these cases, peaks in the diffraction pattern (peaks near the (110) diffraction line of the BCC structure) are waveform-separated into the amorphous phase and the crystalline phase (iron with a BCC structure). If the peak height of the crystalline phase is 1 / 20 or less of the peak height of the amorphous phase, it is determined that the peak of iron with a BCC structure is not observed in the diffraction pattern of the X-ray diffractometer. Note that the peak of iron with a BCC structure is confirmed by both the (110) and (200) diffraction lines. Even if the peak of iron with a BCC structure is not observed in the diffraction pattern, traces of crystalline phase may be observed using a transmission electron microscope. However, because it is difficult to quantify these traces of crystalline phase and their impact on magnetic properties is negligible, even if traces of crystalline phase are observed using a transmission electron microscope, the amorphous alloy is considered to consist solely of an amorphous phase.

[0049] [Nanocrystalline alloy] The nanocrystalline alloy 10 in embodiments 1 and 2 comprises an amorphous phase 16 and multiple crystalline phases 14 formed within the amorphous phase 16. The proportion of crystalline phase 14 in alloy 10 may be sufficient to achieve the effects of embodiments 1 and 2. For example, alloy 10 contains crystalline phase 14 to the extent that peaks of iron with a BCC structure are observed in the diffraction pattern of the X-ray diffractometer described above. For example, when observed with a transmission electron microscope at a magnification of 300,000 times, for a plate-shaped sample, at a position at the center of the sample's width direction and approximately 1 / 8 of the total thickness from the sample surface, or for a powder-shaped sample, at a position approximately 1 / 8 of the diameter from the sample surface close to the average particle size, alloy 10 may contain 10% to 70% by area of ​​crystalline phase 14. If the amount of crystalline phase 14 is large, the alloy becomes brittle and is prone to breakage during winding. Therefore, the amount of crystalline phase 14 can be appropriately adjusted depending on the application form. [Example]

[0050] The samples were prepared as follows.

[0051] [Manufacturing amorphous alloys] The starting materials for the alloys were prepared as reagents, including iron (impurities of 0.01 wt% or less), boron (impurities less than 0.5 wt%), triiron phosphide (impurities less than 1 wt%), and copper (impurities less than 0.01 wt%). It was confirmed in advance that no element loss or contamination occurred during the process of producing nanocrystalline alloys from the mixture of these reagents. For this confirmation, the B concentration of the chemical elements in the amorphous and nanocrystalline alloys was determined by absorptiometry, the C concentration by infrared spectroscopy, and the P and Si concentrations by inductively coupled plasma atomic emission spectroscopy. The Fe concentration was determined by subtracting the total concentration of chemical elements other than Fe from 100% and taking the remainder.

[0052] A 200 gram mixture of the desired chemical composition was prepared. The mixture was heated in a crucible under argon to form a homogeneous molten metal. The molten metal was solidified in a copper mold to produce an ingot.

[0053] An amorphous alloy was produced from an ingot using the single-roll process. A 30-gram ingot was melted in a quartz crucible and ejected onto a pure copper rotating roll through a nozzle with a 10 mm x 0.3 mm opening. An amorphous ribbon 10 mm wide and 20 μm thick was formed on the rotating roll as an amorphous alloy. The amorphous ribbon was peeled off from the rotating roll using an argon gas jet. Using an X-ray diffractometer and the above-mentioned method, it was confirmed that the amorphous ribbon was an amorphous alloy consisting only of amorphous material.

[0054] Nanocrystalline alloy ribbons were produced from amorphous alloys by heat treatment in an argon gas stream using an infrared gold image furnace. The heat treatment conditions were a heating rate of 400°C / min, a holding temperature (Tx1 + 20°C), a holding period of 1 min, and a cooling rate of 0.2–0.5°C / s. Tx1 and Tx2 were determined from DSC curves obtained by heating the amorphous alloy to approximately 650°C at a constant heating rate of 40°C / min. Furthermore, TL was determined by differential thermal analysis (DTA) by heating the ingot to 1350°C at a constant heating rate of 10°C / min and then cooling at a constant heating rate of 10°C / min, from the rise temperature of the first peak during cooling.

[0055] Table 1 shows the chemical compositions (concentrations) in the examples and comparative examples. [Table 1]

[0056] Table 2 shows Tx1, Tx2, maximum temperature Tmax, Tx1 / TL × 100 (Tx1 / TL multiplied by 100), saturation magnetic flux density Bs, and coercive force Hc for the examples and comparative examples. The coercive force and saturation magnetic flux density of the nanocrystalline alloys were measured using a DC magnetization characteristic measurement device model BHS-40 and a vibrating sample magnetometer PV-M10-5, respectively. [Table 2]

[0057] The Fe concentration CFe is constant at 83.3 atomic percent, and the Cu concentration CCu is constant at 0.7 atomic percent. In samples No. 1 to No. 7, the B concentration CB is constant at 8.0 atomic percent, the sum of the P concentration CP and the Si concentration CSi is 8.0 atomic percent, and CP and CSi are varied. In samples No. 8 to No. 13, the B concentration CB is constant at 10.0 atomic percent, the sum of the P concentration CP and the Si concentration CSi is 6.0 atomic percent, and CP and CSi are varied. In sample No. 8, CSi is 0.0 atomic percent. In sample No. 14, the B concentration CB is 12.0 atomic percent, the sum of the P concentration CP and the Si concentration CSi is 4.0 atomic percent, and CP and CSi are 4.0 atomic percent and 0.0 atomic percent, respectively.

[0058] Sample No. 1 corresponds to Example 1, Samples No. 2 to No. 8 correspond to Comparative Examples 1 to 7, respectively, Samples No. 9 to No. 11 correspond to Examples 2 to 4, respectively, and Samples No. 12 to No. 14 correspond to Comparative Examples 8 to 10, respectively. Examples 1 and 2 correspond to Examples of Embodiment 1, and Examples 3 and 4 correspond to Examples of Embodiment 2.

[0059] Referring to Tables 1 and 2, first comparing samples No. 8 and No. 14, which contain 0.0 atomic % CSi, sample No. 8, which has a higher CP, has a lower coercive force Hc than No. 14. Comparing samples No. 1 to No. 5 with samples No. 9 to No. 13, which contain the same CSi, samples No. 1 to No. 5, which have a higher CP, have a lower coercive force Hc. This is thought to be because the size of the crystalline phase is reduced by the addition of P.

[0060] However, as CP increases, Tx2 decreases. For example, in samples No. 1, No. 8, and No. 14, Tx2 is approximately 520°C. If Tx2 is low, the difference between Tmax and Tx1 becomes small, making it difficult to control the temperature and facilitating the formation of compound crystalline phases, making it difficult to control the structure. Therefore, by adding Si, Tx2 can be increased. If CSi becomes too high, Hc increases.

[0061] To lower the coercive force Hc to less than 5.0 A / m, increase Tx2 to more than 515°C, and increase Tx1 / TL × 100 to more than 36, CP is preferably 5.0 atomic % or more, more preferably 6.0 atomic % or more. CSi is preferably 0.4 atomic % or more, more preferably 0.5 atomic % or more, and even more preferably 0.7 atomic % or more. CSi is preferably 1.9 atomic % or less, more preferably 1.4 atomic % or less, and even more preferably 1.0 atomic % or less.

[0062] To lower the coercive force Hc to less than 8.0 A / m, increase Tx2 to more than 540°C, and increase Tx1 / TL×100 to more than 38, CP is preferably 3.0 atomic % or more, and more preferably 3.6 atomic % or more. CSi is preferably 1.1 atomic % or more, more preferably 1.5 atomic % or more, and even more preferably 2.0 atomic % or more. CSi is preferably 4.0 atomic % or less, and more preferably 3.5 atomic % or less.

[0063] Although the preferred embodiments of the invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications and variations are possible within the scope of the gist of the invention as set forth in the claims. [Explanation of symbols]

[0064] 10 alloy 14 Crystalline phase 16 Amorphous phase

Claims

1. having an amorphous phase, the average Fe concentration of the entire alloy is 82.0 atomic % or more and 88.0 atomic % or less; the average Cu concentration in the entire alloy is 0.5 atomic % or more and 1.0 atomic % or less; the average P concentration of the entire alloy is 5.5 atomic % or more and 9.0 atomic % or less; the average B concentration of the entire alloy is 6.0 atomic % or more and 10.0 atomic % or less; the average Si concentration of the entire alloy is 0.9 atomic % or more and 1.9 atomic % or less; the average C concentration of the entire alloy is 0 atomic % or more and 2.0 atomic % or less; The average impurity concentration of the entire alloy for impurities other than Fe, Cu, P, B, Si, and C is 0 atomic % or more and 0.3 atomic % or less, the sum of the average Fe concentration, the average Cu concentration, the average P concentration, the average B concentration, the average Si concentration, the average C concentration, and the average impurity concentration is 100.0 atomic %; (average B concentration - average Si concentration) is 6.5 atomic % or more and 9.5 atomic % or less; alloy.

2. the average Fe concentration is 83.0 atomic % or more and 88.0 atomic % or less, the average Cu concentration is 0.5 atomic % or more and 0.9 atomic % or less, the average P concentration is 5.5 atomic % or more and 8.0 atomic % or less, the average Si concentration is 0.9 atomic % or more and 1.4 atomic % or less, the average C concentration is 0 atomic % or more and 0.1 atomic % or less, 2. The alloy of claim 1, wherein the average impurity concentration is greater than or equal to 0 atomic percent and less than or equal to 0.1 atomic percent.

3. 3. The alloy according to claim 1, which consists solely of the amorphous phase.

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