Fe-P-Cr ALLOY THIN PLATE AND METHOD FOR MANUFACTURING SAME

Abstract

The present invention relates to an Fe—P—Cr alloy thin plate and a method for manufacturing the same. An embodiment of the present invention provides an Fe—P—Cr alloy thin plate including, in terms of wt %, P (6.0-13.0%), Cr (0.002-0.1%), and the balance of Fe and other inevitable impurities.

Claims

1-29. (canceled)

30. An Fe—P—Cr alloy thin plate comprising, in terms of wt %, P (6.0-13.0%), Cr (0.002-0.1%), and the balance of Fe and other inevitable impurities.

31. The Fe—P—Cr alloy thin plate of claim 30, wherein the Fe—P—Cr alloy thin plate further includes Ni (0.5-5.0%) in terms of wt %.

32. The Fe—P—Cr alloy thin plate of claim 31, wherein the thin plate has Vickers hardness of less than or equal to 600 HV.

33. The Fe—P—Cr alloy thin plate of claim 32, wherein the thin plate has a saturation magnetic flux density of greater than or equal to 1.5 T.

34. The Fe—P—Cr alloy thin plate of claim 33, wherein the thin plate has a thickness of 1 μm to 100 μm.

35. The Fe—P—Cr alloy thin plate of claim 34, wherein the Fe—P—Cr alloy thin plate has a mixed form of amorphous and crystal grains.

36. The Fe—P—Cr alloy thin plate of claim 35, wherein the crystal grain has a particle diameter of greater than or equal to 0.1 nm and less than or equal to 100 nm.

37. The Fe—P—Cr alloy thin plate of claim 36, wherein a volume fraction of the crystal grain based on an amorphous matrix is 1% to 10%.

38. A method of manufacturing an Fe—P—Cr alloy thin plate, comprising: forming a plating solution including an iron compound, a phosphorus compound, and a chromium compound; applying a current to the formed plating solution; electrodepositing an Fe—P—Cr alloy layer including, in terms of wt %, P (6.0-13.0%), Cr (0.002-0.1%), and the balance of Fe and other inevitable impurities on a cathode plate using the current; and delaminating the Fe—P—Cr alloy layer from the cathode plate to obtain an Fe—P—Cr alloy thin plate.

39. The method of manufacturing an Fe—P—Cr alloy thin plate of claim 38, wherein the Fe—P—Cr alloy thin plate has a thickness of 1 μm to 100 μm.

40. The method of manufacturing an Fe—P—Cr alloy thin plate of claim 38, wherein the forming of the plating solution including the iron compound, the phosphorus compound, and the chromium compound includes forming a plating solution including an iron compound, a phosphorus compound, a chromium compound, and a nickel compound.

41. The method of manufacturing an Fe—P—Cr alloy thin plate of claim 40, wherein in the forming of the plating solution including the iron compound, the phosphorus compound, the chromium compound, and the nickel compound, a concentration of the iron compound in the plating solution is 0.5 M to 4.0 M, and the iron compound includes FeSO.sub.4, Fe(SO.sub.3NH.sub.2).sub.2, FeCl.sub.2, or a combination thereof.

42. The method of manufacturing an Fe—P—Cr alloy thin plate of claim 41, wherein in the forming of the plating solution including the iron compound, the phosphorus compound, the chromium compound, and the nickel compound, a concentration of the phosphorus compound in the plating solution is 0.01 M to 3.0 M, and the phosphorus compound includes NaH.sub.2PO.sub.2, H.sub.3PO.sub.2, H.sub.3PO.sub.3, or a combination thereof.

43. The method of manufacturing an Fe—P—Cr alloy thin plate of claim 42, wherein in the forming of the plating solution including the iron compound, the phosphorus compound, the chromium compound, and the nickel compound, a concentration of the chromium compound in the plating solution is 0.001 M to 2.0 M, and the chromium compound includes CrCl.sub.3, Cr.sub.2(SO.sub.4).sub.3, CrO.sub.3, or a combination thereof.

44. The method of manufacturing an Fe—P—Cr alloy thin plate of claim 43, wherein in the forming of the plating solution including the iron compound, the phosphorus compound, the chromium compound, and the nickel compound, a concentration of the nickel compound in the plating solution is 0.1 M to 3.0 M, and the nickel compound includes NiSO.sub.4, NiCl.sub.2, or a combination thereof.

45. The method of manufacturing an Fe—P—Cr alloy thin plate of claim 40, wherein the forming of the plating solution including the iron compound, the phosphorus compound, the chromium compound, and the nickel compound includes forming a plating solution including the iron compound, the phosphorus compound, the chromium compound, the nickel compound, and an additive, wherein a concentration of the additive in the plating solution is 0.001 M to 0.1 M.

46. The method of manufacturing an Fe—P—Cr alloy thin plate of claim 38, wherein in the forming of the plating solution including the iron compound, the phosphorus compound, and the chromium compound, pH of the plating solution is 1 to 4.

47. The method of manufacturing an Fe—P—Cr alloy thin plate of claim 38, wherein in the forming of the plating solution including the iron compound, the phosphorus compound, and the chromium compound, a temperature of the plating solution is 30° C. to 100° C.

48. The method of manufacturing an Fe—P—Cr alloy thin plate of claim 38, wherein in the applying of a current to the formed plating solution, a current density is 1 A/dm.sup.2 to 100 A/dm.sup.2.

49. The method of manufacturing an Fe—P—Cr alloy thin plate of claim 38, wherein the electrodepositing of the Fe—P—Cr alloy layer including, in terms of wt %, P (6.0-13.0%), Cr (0.002-0.1%), and the balance of Fe and other inevitable impurities on a cathode plate using the current includes electrodepositing an Fe—P—Cr—Ni alloy layer including, in terms of wt %, P (6.0-13.0%), Cr (0.002-0.1%), Ni (0.5-5.0%), and the balance of Fe and other inevitable impurities on a cathode plate using the current.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0044] FIG. 1 shows an XRD analysis result of an Fe-11 wt % P material.

[0045] FIG. 2 shows an XRD analysis result of an Fe-11 wt % P-0.0023 wt % Cr material according to an embodiment of the present invention.

DETAILED DESCRIPTION

[0046] Advantages and features of the present invention and methods to achieve them will become apparent from exemplary embodiments described below in detail with reference to the accompanying drawings. However, as those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention, and on the contrary, exemplary embodiments introduced herein are provided to make disclosed contents thorough and complete and sufficiently transfer the spirit of the present invention to those skilled in the art. Therefore, the present invention will be defined only by the scope of the appended claims. Like reference numerals refer to like elements throughout the specification.

[0047] In some exemplary embodiments, detailed description of well-known technologies will be omitted to prevent the disclosure of the present invention from being interpreted ambiguously. Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by a person skilled in the art. Through the specification, unless explicitly described to the contrary, the word “comprise” and variations such as “comprises” or “comprising” will be understood to imply the inclusion of stated elements but not the exclusion of any other elements. Further, the singular forms are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0048] An Fe—P—Cr alloy thin plate according to an embodiment of the present invention is an Fe—P—Cr alloy thin plate including, in terms of wt %, P (6.0-13.0%), Cr (0.002-0.1%), and the balance of Fe and other inevitable impurities.

[0049] The thin plate may be an Fe—P—Cr alloy thin plate that further includes Ni at 0.5-5.0% in terms of wt %.

[0050] Hereinafter, reason for limiting components in an embodiment of the present invention are illustrated.

[0051] P plays a role of increasing resistivity and thus decreasing an iron loss.

[0052] As more P is added, an effect of increasing resistivity is simultaneously obtained. However, when the P is included in an amount of less than 6 wt % during manufacture in an electro-forming method, an amorphous phase is not formed, and thus an effect of additionally increasing resistivity may not be expected. In addition, when P is included in an amount of greater than 13 wt %, the obtained alloy may not be commercially available due to deteriorated workability.

[0053] Cr plays a role of reducing high frequency iron loss due to formation of a crystal grain.

[0054] When Cr is included in an amount of less than 0.002 wt %, characteristics of forming crystal grains are deteriorated, and thus an amorphous-crystal grain composite is not formed. Accordingly, the high frequency iron loss may be difficult to reduce, but when Cr is included in an amount of greater than 0.1 wt %, workability may be deteriorated, and thus Cr is preferably included in an amount of less than or equal to 0.1 wt %.

[0055] In addition, when Cr is included in an amount of greater than or equal to 0.002 wt %, saturation magnetic flux density may be improved through formation of amorphous-crystal grain composites up to greater than or equal to 1.5 T, which is high enough to be used for a driving motor and the like.

[0056] Accordingly, the Cr-containing thin plate is a mixed form of amorphous and crystal grain, and herein, the crystal grain has a volume fraction of 1% to 10% relative to the amorphous matrix. When the range is satisfied, the saturation magnetic flux density may be improved.

[0057] In addition, the crystal grain in the thin plate may have a particle diameter of greater than or equal to 0.1 nm and less than or equal to 100 nm.

[0058] In this way, when nanocrystal grains having a size within the range are present inside the amorphous matrix, the saturation magnetic flux density may be improved compared with an amorphous single phase. Accordingly, when the crystal grain has a size of greater than or equal to 100 nm, an effect of deteriorating iron loss and increasing the saturation magnetic flux density may be reduced.

[0059] The particle diameter indicates a diameter or size of a particle, and is defined as a diameter in an embodiment of the present invention and hereinafter.

[0060] In addition, a particle diameter of a crystal grain in the present specification is calculated by putting a diffraction angle and intensity of a diffraction beam from data obtained by using an XRD analysis into the Scherrer equation.

[0061] Ni plays a role of weakening hardness and improving workability.

[0062] When Ni is included in an amount of greater than or equal to 0.5 wt % and less than or equal to 5.0 wt %, hardness may be weakened, and thus workability may be improved.

[0063] However, when Ni is included in an amount of greater than 5.0 wt %, the saturation magnetic flux density is decreased to less than 1.5 T, and the obtained alloy may not be used as a material for a driving motor and the like. Accordingly, in order to secure industrial usage of the obtained alloy, Ni should be used within the range, and the saturation magnetic flux density should be greater than or equal to 1.5 T. The higher the saturation magnetic flux density is, the better, but the saturation magnetic flux density should specifically be in a range of greater than or equal to 1.5 but less than or equal to 2.0 T in the present specification.

[0064] Furthermore, the Ni-containing thin plate may have Vickers hardness of less than or equal to 600 HV. When Vickers hardness is within the range, workability of a thin plate may be improved. Specifically, Vickers hardness may be in a range of greater than or equal to 300 HV and less than or equal to 600 HV.

[0065] In addition, the Fe—P—Cr alloy thin plate may have a thickness of 1 μm to 100 μm.

[0066] The range is a general thickness range of a thin plate, but the present invention is not limited thereto.

[0067] Hereinafter, a method for manufacturing the Fe—P—Cr alloy thin plate according to an embodiment of the present invention is illustrated.

[0068] The method for manufacturing the Fe—P—Cr alloy thin plate includes preparing a plating solution including an iron compound, a phosphorus compound, and a chromium compound.

[0069] The forming of the plating solution including the iron compound, the phosphorus compound, and the chromium compound may include forming a plating solution by further including a nickel compound.

[0070] The iron compound may be included in a concentration range of 0.5 M to 4.0 M in the plating solution. When this range is satisfied, an Fe—P—Cr plating layer may be properly formed.

[0071] For specific examples, the iron compound may be FeSO.sub.4, Fe(SO.sub.3NH.sub.2).sub.2, FeCl.sub.2, or a combination thereof. However, the present invention is not limited thereto.

[0072] The phosphorus compound may be included in a concentration range of 0.01 M to 3.0 M in the plating solution. When this range is satisfied, the Fe—P—Cr plating layer may be properly formed.

[0073] For specific examples, the phosphorus compound may be NaH.sub.2PO.sub.2, H.sub.3PO.sub.2, H.sub.3PO.sub.3, or a combination thereof. However, the present invention is not limited thereto.

[0074] The chromium compound may be included in a concentration range of 0.001 M to 2.0 M in the plating solution. When this range is satisfied, the Fe—P—Cr plating layer may be properly formed.

[0075] For specific examples, the chromium compound may be CrCl.sub.3, Cr.sub.2(SO.sub.4).sub.3, CrO.sub.3, or a combination thereof. However, the present invention is not limited thereto.

[0076] The nickel compound in the plating solution may be included in a concentration range of 0.1 M to 3.0 M. When this range is satisfied, an Fe—P—Cr plated layer may be properly formed. For specific examples, the nickel compound may be NiSO.sub.4, NiCl.sub.2, or a combination thereof. However, the present invention is not limited thereto.

[0077] In addition, an additive may be further added to the plating solution.

[0078] The additive may be used in a concentration range of 0.001 M to 0.1 M. When the range is not satisfied, an Fe—P—Cr plated layer may not be properly formed. In addition, when the additive in added in an amount of greater than 0.1 M, an effect of forming a plating layer may be excessive, and further addition is ineffectual, and thus is not economical.

[0079] More specifically, glycolic acid, saccharin, beta-alanine, DL-alanine, succinic acid, or a combination thereof may be included.

[0080] The plating solution may have pH ranging from 1 to 4 and a temperature ranging from 30° C. to 100° C.

[0081] The pH of the plating solution may be adjusted within a range of 1 to 4 by adding at least one acid and/or at least one base.

[0082] Accordingly, when the pH of the plating solution is satisfied, the Fe—P—Cr plated layer may be properly formed.

[0083] In addition, when a temperature in a plating bath is in a range of 30° C. to 100° C., the Fe—P—Cr plated layer may be properly formed.

[0084] Subsequently, a current is applied to the prepared plating solution.

[0085] The current may be a DC current or a pulse current, and may have current density in a range of 1 A/dm.sup.2 to 100 A/dm.sup.2. When the current density is within the range, the Fe—P—Cr plated layer may be properly formed.

[0086] Within the range, the current density may be changed to adjust a P composition.

[0087] In addition, the current may be used to electroplate an Fe—P—Cr alloy layer including P (6.0-13.0%), Cr (0.002-0.1%), and the balance of Fe and other inevitable impurities in terms of wt % on a cathode plate.

[0088] The current may also be used to electroplate an Fe—P—Cr—Ni alloy layer including P (6.0-13.0%), Cr (0.002-0.1%), Ni (0.5-5.0%), and the balance of Fe and other inevitable impurities in terms of wt % on a cathode plate.

[0089] Lastly, the Fe—P—Cr alloy layer is delaminated from the cathode plate to obtain an Fe—P—Cr alloy thin plate.

[0090] The cathode plate may include stainless steel, titanium, or a combination thereof. However, the cathode plate is not limited thereto, and may include all materials having acid resistance and an oxide film.

[0091] The Fe—P—Cr alloy thin plate may have a thickness of 1 μm to 100 μm.

[0092] The range is a general range of a thin plate, and the present invention is not limited thereto.

[0093] Hereinafter, examples are described in detail. However, the following examples show exemplary embodiments of the present invention, but do not limit it.

Example 1

[0094] A plating solution including an iron compound, a phosphorus compound, and a chromium compound according to an embodiment of the present invention was prepared, and a current was applied to the plating solution.

[0095] The current was used to electroplate an Fe—P—Cr alloy layer including, in terms of wt %, P (6.0-13.0%), Cr (0.002-0.1%), and the balance of Fe and other inevitable impurities on a cathode plate.

[0096] Subsequently, the Fe—P—Cr alloy layer was peeled off from the cathode plate to obtain an Fe—P—Cr thin plate.

[0097] The contents of P and Cr were changed within the above ranges to perform an experiment, and its results are shown in Table 1.

TABLE-US-00001 TABLE 1 P Cr Average Iron loss content content crystal grain W10/400 [wt %] [wt %] Microstructure size (nm) [W/kg] Workability Comparative 5.78 0 crystalline 15.0 11.3 — material 1 Comparative 6.15 0 amorphous 17.1 8.6 — material 2 Inventive 6.1 0.0022 mixed form of 8.2 5.1 Excellent material 1 amorphous- nanocrystal grain Comparative 13.3 0.0025 mixed form of 15.0 5.02 Inferior material 3 amorphous- nanocrystal grain Comparative 12.5 0.12 mixed form of 10.1 5 Inferior material 4 amorphous- nanocrystal grain Comparative 6.2 0.13 mixed form of 8.2 5.15 Inferior material 5 amorphous- nanocrystal grain Inventive 6.22 0.097 mixed form of 7.4 5.09 Excellent material 2 amorphous- nanocrystal grain Inventive 12.6 0.095 amorphous- mixed 9.5 4.9 Excellent material 3 form of amorphous- nanocrystal grain

[0098] As shown in Table 1, an Fe—P—Cr alloy manufactured in an electrofoming method according to an exemplary embodiment of the present invention, unlike an Fe—P alloy, showed a mixed phase of amorphous and crystal grains. The reason is that the mixed phase of amorphous and crystal grain due to addition of Cr lowered an iron loss compared with a single amorphous phase.

[0099] In addition, as described above, a nano-sized crystal grain was present in a fraction of 1-10% based on the entire volume of the mixed phase of amorphous-nanocrystal grains of the inventive material.

[0100] In addition, the workability in Table 1 was evaluated by judging whether an alloy was cracked or not during a punching process, and as a result, the Fe—P—Cr alloy manufactured in the electroforming method turned out to be excellent compared with an alloy manufactured in other methods.

Example 2

[0101] A plating solution including an iron compound, a phosphorus compound, and a chromium compound according to an embodiment of the present invention was prepared, and a current was applied to the plating solution. The current was used to electrodeplate an Fe—P—Cr—Ni alloy layer including P (6.0-13.0%), Cr (0.002-0.1%), Ni (0.5-5.0%), and the balance of Fe and other inevitable impurities in terms of wt % on a cathode plate.

[0102] Accordingly, the Fe—P—Cr—Ni alloy layer was peeled off from the cathode plate to obtain an Fe—P—Cr—Ni thin plate.

[0103] The contents of P, Cr, and Ni were changed within the above range to perform an experiment, and the experiment results are shown in Table 2.

TABLE-US-00002 TABLE 2 Saturation P Cr Ni Vickers magnetic content content content hardness flux density [wt %] [wt %] [wt %] [HV] [T] Inventive material 6.1 0.0022 0 605 1.65 A1 Inventive material 12.5 0.095 0 613 1.62 A2 Inventive material 6.12 0.0025 0.53 537 1.65 A3 Inventive material 12.4 0.097 0.52 545 1.62 A4 Comparative 6.15 0.0023 10.2 533 1.46 material A1 Comparative 12.6 0.097 10.1 541 1.43 material A2 Inventive material 6.13 0.0025 9.8 533 1.55 A5 Inventive material 12.7 0.096 9.8 541 1.52 A6

[0104] Table 2 shows hardness and saturation magnetic flux density results depending on components of an Fe—P—Ni—Cr material manufactured through electro-formation.

[0105] As shown in Table 2, when Ni was added, hardness was deteriorated, but when the Ni was included in an amount of greater than 5.0 wt %, saturation magnetic flux density was less than 1.5 T.

[0106] Although the exemplary embodiments of the present invention have been described with reference to the accompanying drawings, it will be apparent to those skilled in the art that various modifications and changes may be made thereto without departing from the technical spirit or essential features of the invention.

[0107] Therefore, the aforementioned embodiments should be understood to be exemplary but not limiting the present invention in any way. The scope of the present invention is defined by the appended claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the appended claims and their equivalents should be interpreted as falling within the scope of the present invention.