KR100505002B1 - Nani invar alloyes and the process of producing the same - Google Patents

Abstract

The present invention is a novel Fe-Ni alloy having a Ni content in the range of 33 to 42 wt% using an electroplating (forming) method, specifically, a nano-invar having a nanocrystalline structure having a grain size of 5 to 15 nm. This is a description of the electrolytic (plating, molding) solution for producing alloys, and process conditions. In particular, in the alloy prepared according to the present invention, the alloy having a composition of 64 wt% Fe-36 wt% Ni was very small in size of 5 to 7 nm in some cases (10) nm. Conventional alloying methods for producing Fe-Ni alloys with low thermal expansion properties including Invar Alloy (64% Fe-36% Ni) have to go through various processes such as melting, casting, forging, rolling, and heat treatment. do. However, according to the present invention, FeSO ₄ · 7H ₂ O (Ferrous Sulfate), NiSO ₄ · 6H ₂ O (Nickel Sulfate), NiCl ₂ · 6H ₂ O (Nickel Chloride), FeCl ₂ · 4H ₂ O (Ferrous Chloride) Some of Ni (NH ₂ SO ₃ ) ₂ (Nickel Sulfamate) and electrolytic (plating, molding) solution containing Saccharin (C ₇ H ₄ NO ₃ SNa, Sodium Saccharin) as a stress relaxation agent The Fe-Ni alloy, which is electroplated (molded) with a continuous direct current or pulsed direct current and electrodeposited on the cathode, is separated from the electrode surface and manufactured into a thin plate having a thickness of 1 to 200 μm. In particular, the electrolyte solution is 32 to 53 g of FeSO ₄ · 7H ₂ O (Ferrous Sulfate) or FeCl ₂ · 4H ₂ O (Ferrous Chloride) or a mixture thereof, 97 g of NiSO ₄ · 6H ₂ O (Nickel Sulfate) per liter of water. Or NiCl ₂ · 6H ₂ O (Nickel Chloride) or Ni (NH ₂ SO ₃ ) ₂ (Nickel Sulfamate) or mixtures thereof, 20-30 g of boric acid (H ₃ BO ₃ , Boric acid), saccharin (C ₇ H ₄ NO ₃ SNa, Sodium Saccharin (1-3g), sodium lauryl sulfate (C ₁₂ H ₂₅ O ₄ SNa, Sodium Lauryl Sulfate) 0.1-0.3g, sodium chloride (NaCl, Sodium Chloride) 20-40g. Nano invar alloy foils or thin plates produced in this way are used to adjust the current density, pH value, etc. together with the changes in the composition of iron and nickel compounds to adjust the Ni content in the alloy between 32.7wt% and 38.8wt%. It can be changed in the range of. The crystal grains constituting the Invar alloy thin plate manufactured by the present invention have a distribution of 5 to 15 nanometers, and thus exhibit excellent mechanical properties than those of the Invar alloy by the conventional method, and have a thermal expansion coefficient of 0 or a negative value at a certain temperature range. It shows new physical properties such as having.

Description

Nano inva alloy and manufacturing method thereof {NANI INVAR ALLOYES AND THE PROCESS OF PRODUCING THE SAME}

Fe-Ni alloys exhibit various properties depending on the Ni content, and low thermal expansion properties occur when the Ni content is in the range of 20% to 50% by weight (DR Rancourt, S. Chehab and G. Lamarche, J. Mag. Mag). Mater. 78 (1989) 129). Among these, an alloy of 64% Fe-36% Ni composition, called Invar alloy, has a coefficient of thermal expansion close to zero, and since Guillaume first invented in 1897 (CE Guillaume, CR Acad. Sci. Paris 124 (1897) It is produced as a representative low thermal expansion alloy and has been widely used commercially.

INVAR ALLOY (Fe-36% Ni), which is representative of materials with low coefficient of thermal expansion, is a standard measuring device, piston of internal combustion engine, bimetal, temperature control device, liquid gas storage device, integrated circuit lead frame. ), Shadow mask which is an essential part of cathode ray tube (CRT) for color monitor of TV and personal computer (PC), electric electronic device, etc.

 In addition, shadow masks made of Inva alloy are expected to be used in field emission displays (FEDs) for flat panel monitors, which are being developed in recent years, and lead frames supporting semiconductor integrated circuit (IC) chips. frame can also be used.

In particular, if the coefficient of thermal expansion of the alloy is negative in the environment in which the alloy is used, that is, the alloy may shrink as the temperature of the environment in which the alloy is used increases. In such a case, if an alloy with a negative thermal expansion coefficient is developed in a temperature range of use, it may be very important.

As described above, there are various methods of manufacturing a Fe-Ni alloy thin plate applied to various fields, but now cold rolling is mainly used. When cold rolling is used, vacuum melting, forging, hot rolling, normalizing, primary cold rolling, intermediate annealing, secondary cold rolling, and final annealing in a reducing atmosphere are required. In order to manufacture a thin plate, multi-stage rolling must be performed (see US Patent 494834), which is not only difficult to obtain a homogeneous product but also a high manufacturing cost. In addition, due to the vacuum melting required for such a process, there is a problem that large-scale equipment such as forging equipment, hot rolling mill, multi-stage rolling mill, etc., and plastic processing to make the shape required for the final product is very difficult. In addition, there is a problem in that the coefficient of thermal expansion is sensitive to changes in impurities and process conditions involved in the process (see Metals Handbook, 9th ed. Vol. 3, ASM (1980) 889).

In order to overcome these limitations of the conventional manufacturing method, a lot of researches have recently been made on the production of Fe-Ni alloys by electroplating (molding) (pole molding). However, the Invar alloy manufacturing method by such an electroplating method is difficult to find the proper electrolyte solution and process conditions until now because of the difficult process conditions, such as the selection process temperature, current density of the appropriate electrolyte solution.

Therefore, it is required to find out the electrolytic (plating, molding) solution and process conditions for producing reproducible nano invar alloy. In particular, in order to be commercially meaningful, since the width of the plate to be plated should be 300 mm (30 cm) or more, it is very necessary to find an applicable electroplating environment even in this case.

An object of the present invention is an electrolytic (plating, molding) solution and process conditions that can be produced by using the electroplating (electrodeposition) or electroforming method of the nano invar alloy sheet having a nano-sized grain size To provide.

Another object of the present invention is to provide a Fe-Ni alloy having a negative coefficient of thermal expansion at a constant temperature range.

Another object of the present invention is to provide a Fe-Ni alloy having excellent mechanical properties than the conventional Invar alloy.

Another object of the present invention is to provide a method for producing a Fe-Ni alloy having a negative coefficient of thermal expansion in a constant temperature section using an electroplating method.

In order to achieve this purpose, in the present invention, 32 to 53 g of 1 L of water

FeSO ₄ · 7H ₂ O (Ferrous Sulfate) or FeCl ₂ · 4H ₂ O (Ferrous Chloride) or mixtures thereof, 97 g of NiSO ₄ · 6H ₂ O (Nickel Sulfate) or NiCl ₂ · 6H ₂ O (Nickel Chloride) Or Ni (NH ₂ SO ₃ ) ₂ (Nickel Sulfamate) or a mixture thereof, 20-30 g of boric acid (H ₃ BO ₃ , Boric acid), 1-3 g of saccharin (C ₇ H ₄ NO ₃ SNa, Sodium Saccharin), sodium A solution containing 0.1 to 0.3 g of lauryl sulfate (C ₁₂ H ₂₅ O ₄ SNa, Sodium Lauryl Sulfate) and _{20 to} 40 g of sodium chloride (NaCl, Sodium Chloride) is used as an electrolyte, and the pH of the electrolyte is 2-3. In the state of the current density is 50 ~ 100mA / cm ² , the temperature of the electrolyte solution 45 ~ 60 ℃ by electroplating method to produce a FeNi alloy with Ni wt% 33 ~ 38%.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic diagram of an electroplating (molding) apparatus used to fabricate a nano invar alloy sheet in the present invention. In Fig. 1, the electrolytic solution 3 used in the present invention is placed in the electrolytic cell 9 and circulated so that the electrolyte flows between the negative electrode 1 and the positive electrode 2 having a distance of 10 mm at a flow rate of 0.1 to 2.0 m / sec. Electroplating (molding) was performed while the pump 5 was operating. 6 is a filter, 7 is a nozzle, and 8 is a circulation pipe. When the Fe-Ni alloy having a thickness of 20 µm was electrodeposited on the sheet material in the cathode, the current supply device 4 was stopped, and then the plated (molded) sheet material was separated from the cathode surface to obtain a thin plate. The plate used for the anode in this device is used by varying the inclination angle (10) according to the flow rate.

The electrolyte used in the present invention is FeSO ₄ · 7H ₂ O (Ferrous Sulfate), NiSO ₄ · 6H ₂ O (Nickel Sulfate), NiCl ₂ · 6H ₂ O (Nickel Chloride), FeCl ₂ · 4H ₂ O (Ferrous Chloride) And Ni (NH ₂ SO ₃ ) ₂ (Nickel Sulfamate), based on boric acid (H ₃ BO ₃ , Boric acid) 20-30g / l, and saccharin (C ₇ H ₄ NO ₃ SNa, Sodium Saccharin A solution containing 1 to 3 g / l, sodium lauryl sulfate (C ₁₂ H ₂₅ O ₄ SNa, Sodium Lauryl Sulfate) and 0.1 to 0.3 g / l, and sodium chloride (NaCl, Sodium Chloride) 20 to 40 g / l.

Among them, boric acid (H ₃ BO ₃ , Boric acid) is 22-25g / l, saccharin (C ₇ H ₄ NO ₃ SNa, Sodium Saccharin) is 2.0-2,4g / l and sodium lauryl sulfate (C ₁₂ H ₂₅ A preferable effect is obtained when 0.1 to 0.2 g / l of O ₄ SNa, Sodium Lauryl Sulfate) and _{30 to} 32 g / l of sodium chloride (NaCl, Sodium Chloride) are contained.

Boric acid is added as a pH buffer, saccharin is a stress relieving agent for plating (molding) material, sodium chloride is used to improve electrolyte conductivity, and sodium lauryl sulfate is added for surfactant function. During electroplating (molding) the pH of the electrolyte is maintained in the range of 2 to 3, the current density is 50 to 100mA / cm ² , the temperature of the electrolyte is carried out at 45 ~ 60 ℃.

The iron compound and the nickel compound are liberated with ions in the electrolyte, and then electrodeposited with a Fe-Ni alloy having a thickness of 1 to 200 μm on the negative electrode plate during electroplating (molding).

Examples of the electrolytic (plating, molding) solution for producing the nano-Inba alloy thin plate used in the present invention by the electroplating (molding) method is shown in Tables 1 to 6.

FeSO ₄ · 7H ₂ O (Ferrous Sulfate) and NiSO ₄ · 6H ₂ O (Nickel Sulfate) solution Example FeSO ₄ 7H ₂ O (g) NiSO ₄ · 6H ₂ O (g) Boric acid (g) Sodium Lauryl Sulfate (g) Saccharin (g) Sodium chloride (g) Fe: Ni molar ratio Ni wt% One 43 97 22 0.1 2.0 32 1: 2.371 38.8 2 48 97 22 0.1 2.0 32 1: 2.124 36.4 3 53 97 22 0.1 2.0 32 1: 1.923 34.2

<1 liter of distilled water>

FeSO ₄ · 7H ₂ O (Ferrous Sulfate) and NiCl ₂ · 6H ₂ O (Nickel Chloride) solution Example FeSO ₄ 7H ₂ O (g) NiCl ₂ · 6H ₂ O (g) Boric acid (g) Sodium Lauryl Sulfate (g) Saccharin (g) Sodium chloride (g) Fe: Ni molar ratio Ni wt% 4 50 97 22 0.1 2.0 32 1: 2.039 36.6

<1 liter of distilled water>

FeCl ₂ · 4H ₂ O (Ferrous Chloride) and NiSO ₄ · 6H ₂ O (Nickel Sulfate) solution Example FeCl ₂ · 4H ₂ O (g) NiSO ₄ · 6H ₂ O (g) Boric acid (g) Sodium lauryl sulfate Saccharin (g) Sodium chloride (g) Fe: Ni molar ratio Ni wt% 5 42 97 22 0.1 2.0 32 1: 2.427 37.5 6 44 97 22 0.1 2.0 32 1: 2.316 36.2

<1 liter of distilled water>

Use FeCl ₂ · 4H ₂ O (Ferrous Chloride) and NiCl ₂ · 6H ₂ O (Nickel Chloride) solution Example FeCl ₂ · 4H ₂ O (g) NiCl ₂ · 6H ₂ O (g) Boric acid (g) Sodium lauryl sulfate Saccharin (g) Sodium chloride (g) Fe: Ni molar ratio Ni wt% 7 44 97 22 0.1 2.0 32 1: 2.317 38.3 8 46 97 22 0.1 2.0 32 1: 2.216 36.2 9 50 97 22 0.1 2.0 32 1: 2.039 32.7

FeSO ₄ · 7H ₂ O (Ferrous Sulfate) and Ni (NH ₂ SO ₃ ) ₂ (Nickel Sulfamate) solution Example FeSO ₄ 7H ₂ O (g) Ni (NH ₂ SO ₃ ) ₂ (g) Boric acid (g) Sodium lauryl sulfate Saccharin (g) Sodium chloride (g) Fe: Ni molar ratio Ni wt% 10 35 97 22 0.1 2.0 32 1: 2.913 36.3 11 37 97 22 0.1 2.0 32 1: 2.755 34.5

<1 liter of distilled water>

Using FeCl ₂ · 4H ₂ O (Ferrous Chloride) and Ni (NH ₂ SO ₃ ) ₂ (Nickel Sulfamate) solution Example FeSO ₄ 7H ₂ O (g) Ni (NH ₂ SO ₃ ) ₂ (g) Boric acid (g) Sodium lauryl sulfate Saccharin (g) Sodium chloride (g) Fe: Ni molar ratio Ni wt% 12 32 97 25 0.2 2.4 30 1: 3.186 37.0 13 34 97 25 0.2 2.4 30 1: 2.998 35.2

<1 liter of distilled water>

<Table 1> shows FeSO ₄ · 7H ₂ O (Ferrous Sulfate) and NiSO ₄ · 6H ₂ O (Nickel Sulfate) as the main components of the plating (molding) solution, keeping the amount of Nickel Sulfate constant at 97g / l While the amount of Ferrous Sulfate was varied in the range of 43 to 53 g / l, Fe-Ni alloys having a desired composition were shown in (Examples 1 to 3).

<Table 2> shows FeSO ₄ · 7H ₂ O (Ferrous Sulfate) and NiCl ₂ · 6H ₂ O (Nickel Chloride) as the main components of the plating (molding) solution, keeping the amount of Nickel Chloride constant at 97g / l In addition, the result of manufacturing the Fe-Ni alloy of a desired composition by making the amount of Ferrous Sulfate 50g / l is shown in (Example 4).

<Table 3> shows FeCl ₂ · 4H ₂ O (Ferrous Chloride) and NiSO ₄ · 6H ₂ O (Nickel Sulfate) as the main components of the plating (molding) solution, and the amount of Nickel Sulfate was kept constant at 97 g / l. While the amount of Ferrous Chloride was changed in the range of 42 to 44 g / l, Fe-Ni alloys having the desired compositions were shown in (Examples 5 to 6).

<Table 4> shows FeCl ₂ · 4H ₂ O (Ferrous Chloride) and NiCl ₂ · 6H ₂ O (Nickel Chloride) as the main components of the plating (molding) solution, and the amount of Nickel Chloride is kept constant at 97 g / l. While changing the amount of Ferrous Chloride in the range of 44-50 g / l, the result of producing Fe-Ni alloy of a desired composition is shown in (Examples 7-9).

<Table 5> shows FeSO ₄ · 7H ₂ O (Ferrous Sulfate) and Ni (NH ₂ SO ₃ ) ₂ (Nickel Sulfamate) as the main components of the plating (molding) solution, and the amount of Nickel Sulfamate was constant at 97g / l. The results of preparing the Fe-Ni alloy of the desired composition by varying the amount of Ferrous Sulfate in the range of 35 to 37 g / l while maintaining it were shown in (Examples 10 to 11).

<Table 6> shows the use of FeCl ₂ · 4H ₂ O (Ferrous Chloride) and Ni (NH ₂ SO ₃ ) ₂ (Nickel Sulfamate) as the main components of the plating (molding) solution, and the amount of Nickel Sulfamate was constant at 97g / l. The results of preparing the Fe-Ni alloy having the desired composition by varying the amount of Ferrous Chloride in the range of 32 to 34 g / l while maintaining it were shown in (Examples 12 to 13).

The Fe-Ni alloy prepared by the electroplating method using the electrolytic solution having such a composition exhibits the characteristics as shown in Table 8 below regardless of the type of the electrolytic solution used in Tables 1 to 6. Some of the important properties of the commercially available Invar alloys shown in Table 7 below are compared with those of the nano Invar alloys prepared according to the present invention (comparative tables are shown in Table 9). It can be seen that the manufactured nano inva alloy exhibits superior material properties than the commercial inva alloy.

Properties of Commercial Invar Density, g / cm ³ -------------------------------------------- ---- 8.1 Tensile strength, MPa ---------------------------------------- 450 ~ 585 Yield strength, MPa ------------------------------------------ 275 ~ 415 Elastic limit, MPa ------------------------------------------- 140 ~ 205 Elongation, % ------------------------------------------------ 30 ~ 45 Reduction in area,% ----------------------------------------- 55 ~ 70 hardness --------------------------------------------- 160 Modulus of elasticity, GPa (10 ⁶ psi) --------------------------- 150 (21.4) Thermoelastic coefficient, mm / mk ----- ---------------------- 500Specific heat, at 25 ~ 100 ℃, J / kg ℃ -------------- ---------- 515Thermal conductivit, at 20 ~ 100 ℃, W / mk --------------------- 11 Electrical resistivity, ml m -------------------------------- 750 ~ 850

Physical Properties of Nano Invar Prepared Hardness, GPa ----------------------------------------------- -5.4 Tensile strength, MPa ----------------------------------------- 1,045Yield strength, MPa ------------------------------------------- 805 Modus of elasticity, GPa ------------------------------------ 85 ~ 120

Comparison of Properties of Commercial Invar and Nano Invar According to the Invention Conventional Inver Nano Invar (Invention) Hardness 2.5 GPa 5.4 GPa Tensike strength 450 ~ 585 MPa 1,045 MPa Yield strength 275-415 MPa 805 MPa

That is, in the case of the nano invar alloy prepared according to the present invention, the hardness (Hardness), tensile strength (Tensile strength), yield strength (Yield strength) has a value of more than twice than that of the commercially available bar alloy. Therefore, in the case of yield strength, the nano invar alloy manufactured according to the present invention is 805 MPa, which is much larger than the yield strength of the conventional commercial bar alloy, 275 to 415 MPa. Applicable

Expansion coefficient of commercial Invar alloy ℃ Coefficient, μm / mK As forged 17 to 10017 to 250 1.663.11

Thermal expansion coefficient of nano invar alloy (Fe-36wt% Ni) prepared according to the present invention ℃ Coefficient, μm / mK As deposited 20 to 100  1.58 20 to 200 -1.78 20 to 300 -2.70 20 to 400 -3.82

<Table 10> is a table showing the average coefficient of thermal expansion according to the temperature section of the commercial Invar alloy. As shown in Table 10, the commercial Invar alloy has an average thermal expansion coefficient of about 1.66 µm / m · K in the range of 17 to 100 ° C. and the thermal expansion coefficient increases as the temperature increases. However, in the case of the nano invar alloy (Fe-36wt% Ni) prepared according to the present invention, the coefficient of thermal expansion shows a value of 1.58 μm / m · K in the range of 20 to 100 ° C., but the coefficient of thermal expansion is around 140 to 150 ° C. After this, if the temperature is increased to 150 ° C. or higher, the coefficient of thermal expansion has a negative value, and the average value in the 20 to 200 ° C. region has a value of −1.78 μm / m · K. This thermal expansion behavior is a feature commonly seen when the Ni content of the nano Invar alloy prepared according to the present invention is 33 to 38 wt%.

Figure 2 is a view showing the change in the coefficient of thermal expansion according to the composition ratio of the nano invar alloy prepared according to the present invention, it shows the fact mentioned above. As shown in the figure, in the case of Ni wt% of 33% and 38%, the coefficient of thermal difference was negative at all temperatures above a certain temperature. Therefore, the nano invar alloy prepared according to the present invention has a thermal expansion coefficient of 0 or a negative value at a predetermined temperature or more, and thus can be applied to new applications requiring such characteristics.

FIG. 3 is a {111} pole figure of the aggregate structure after annealing a commercially available Invar alloy, FIG. 4 (a) is a {100} pole figure of the aggregate structure of a nano invar alloy prepared according to the present invention, and FIG. ) Is the {111} pole figure of the texture after annealing the nano invar alloy prepared according to the present invention.

From the above figures, the annealing of commercially available Invar alloy develops the orientation of {001} <100> as the main orientation, whereas in the case of Nano Invar alloy, {100} // ND fiber dominates in the plated state. It can be seen that when the annealing treatment, the {111} // ND fiber aggregate structure is strongly developed.

The Fe-Ni alloy according to the present invention was found to be 5 ~ 15nm by calculating the size distribution of the crystal grains using X-ray diffraction. Particularly, in the invar alloy composition having a Niwt% of 36%, the grain size was found to be smallest in the range of 5 to 7 nm (10) nm in some cases. This nanocrystal structure seems to explain why the nano invar alloy according to the present invention has a high yield strength.

When the nano invar alloy is manufactured by the electroplating method, which is a single process according to the present invention, mechanical properties are superior to those of commercial invar alloys, and have good low thermal expansion properties and manufacturing costs may be greatly reduced. In particular, since the coefficient of thermal expansion has a negative value above a certain temperature, it is possible to create a new range of industrial use of the nano invar alloy.

1 is a schematic view of an electroplating (molding) apparatus used to manufacture nano invar alloy sheet in the present invention.

2 is a view showing a change in the coefficient of thermal expansion according to the composition ratio of the nano Invar alloy prepared according to the present invention.

Fig. 3 is a {111} pole figure of the texture after annealing a commercially available Invar alloy.

Figure 4 (a) is a {100} pole figure of the texture of the nano Invar alloy prepared according to the present invention

Figure 4 (b) is a {111} pole figure of the texture after annealing the nano invar alloy prepared according to the present invention

Claims (18)

delete 43 to 53 g of FeSO ₄ · 7H ₂ O (Ferrous Sulfate), 97 g of NiSO ₄ · 6H ₂ O (Nickel Sulfate), _{20 to 30} g of boric acid (H ₃ BO ₃ , Boric acid), saccharin (C ₇₎ Solution containing 1.0 to _3.0 g of H ₄ NO ₃ SNa, Sodium Saccharin, 0.1 to 0.3 g of Sodium Lauryl Sulfate (C ₁₂ H ₂₅ O ₄ SNa, Sodium Chloride) to 20 to 40 g Is used as an electrolyte, the pH of the electrolyte is 2 to 3, the current density is 50 to 100mA / cm ² , the temperature of the electrolyte is 45 ~ 60 ℃ grain size formed by the electroplating method is 5 ~ 15nm Fe-Ni alloy having a Ni wt% of 33 to 38%. 50 g of FeSO ₄ · 7H ₂ O (Ferrous Sulfate), 97 g of NiCl ₂ · 6H ₂ O (Nickel Chloride), 20-30 g of boric acid (H ₃ BO ₃ , Boric acid), saccharin (C ₇ H ₄₎ A solution containing 1.0 to 3.0 g of NO ₃ SNa, Sodium Saccharin, 0.1 to 0.3 g of sodium lauryl sulfate (C ₁₂ H ₂₅ O ₄ SNa, Sodium Chloride), and 20 to 40 g of sodium chloride (NaCl) And the pH of the electrolyte is 2 to 3, the current density is 50 to 100mA / cm ² , the temperature of the electrolyte is 45 ~ 60 ℃ characterized in that the grain size formed by the electroplating method is 5 ~ 15nm Fe-Ni alloy with Ni wt% 33-38%. Per 1 liter of water, 42 to 44 g of FeCl ₂ · 4H ₂ O (Ferrous Chloride), 97 g of NiSO ₄ · 6H ₂ O (Nickel Sulfate), 20-30 g of boric acid (H ₃ BO ₃ , Boric acid), saccharin (C ₇ Solution containing 1.0 to _3.0 g of H ₄ NO ₃ SNa, Sodium Saccharin, 0.1 to 0.3 g of Sodium Lauryl Sulfate (C ₁₂ H ₂₅ O ₄ SNa, Sodium Chloride) to 20 to 40 g Is used as an electrolyte, the pH of the electrolyte is 2 to 3, the current density is 50 to 100mA / cm ² , the temperature of the electrolyte is 45 ~ 60 ℃ grain size formed by the electroplating method is 5 ~ 15nm Fe-Ni alloy having a Ni wt% of 33 to 38%. 44 to 50 g of FeCl ₂ · 4H ₂ O (Ferrous Chloride), 97 g of NiCl ₂ · 6H ₂ O (Nickel Chloride), _{20 to 30} g of boric acid (H ₃ BO ₃ , Boric acid), saccharin (C ₇₎ Solution containing 1.0 to _3.0 g of H ₄ NO ₃ SNa, Sodium Saccharin, 0.1 to 0.3 g of Sodium Lauryl Sulfate (C ₁₂ H ₂₅ O ₄ SNa, Sodium Chloride) to 20 to 40 g Is used as an electrolyte, the pH of the electrolyte is 2 to 3, the current density is 50 to 100mA / cm ² , the temperature of the electrolyte is 45 ~ 60 ℃ grain size formed by the electroplating method is 5 ~ 15nm Fe-Ni alloy having a Ni wt% of 33 to 38%. Per liter of water, 35 to 37 g of FeSO ₄ · 7H ₂ O (Ferrous Sulfate), 97 g of Ni (NH ₂ SO ₃ ) ₂ (Nickel Sulfamate), _{20 to 30} g of boric acid (H ₃ BO ₃ , Boric acid), saccharin ( C ₇ H ₄ NO ₃ SNa, Sodium Saccharin (1.0-3.0g), Sodium Lauryl Sulfate (C ₁₂ H ₂₅ O ₄ SNa, Sodium Lauryl Sulfate) 0.1-0.3g, Sodium Chloride (NaCl, Sodium Chloride) 20-40g A solution to be used as an electrolytic solution, wherein the pH of the electrolyte solution is 2 to 3, the current density is 50 to 100 mA / cm ² , and the temperature of the electrolyte solution is 45 to 60 ° C., and the grain size formed by the electroplating method is 5 to 15 nm. Ni-wt% is Fe-Ni alloy, characterized in that 33 to 38%. 32 to 34 g of FeCl ₂ · 4H ₂ O (Ferrous Chloride), 97 g of Ni (NH ₂ SO ₃ ) ₂ (Nickel Sulfamate), 20 to 30 g of boric acid (H ₃ BO ₃ , Boric acid), saccharin C ₇ H ₄ NO ₃ SNa, Sodium Saccharin (1.0-3.0g), Sodium Lauryl Sulfate (C ₁₂ H ₂₅ O ₄ SNa, Sodium Lauryl Sulfate) 0.1-0.3g, Sodium Chloride (NaCl, Sodium Chloride) 20-40g A solution to be used as an electrolytic solution, wherein the pH of the electrolyte solution is 2 to 3, the current density is 50 to 100 mA / cm ² , and the temperature of the electrolyte solution is 45 to 60 ° C., and the grain size formed by the electroplating method is 5 to 15 nm. Ni-wt% is Fe-Ni alloy, characterized in that 33 to 38%. The Fe-Ni alloy according to any one of claims 2 to 7, wherein the NiNi wt% is 33 to 38%, wherein the FeNi alloy has a thickness of 1 to 200 µm. delete The Fe-Ni alloy according to any one of claims 2 to 7, wherein the Ni wt% is 33 to 38%, characterized in that the thermal expansion coefficient of the FeNi alloy is negative at a predetermined temperature or more. The Fe-Ni alloy according to any one of claims 2 to 7, wherein the composition ratio of the FeNi alloy is 64 wt% Fe and 36 wt% Ni. delete 43 to 53 g of FeSO ₄ · 7H ₂ O (Ferrous Sulfate), 97 g of NiSO ₄ · 6H ₂ O (Nickel Sulfate), _{20 to 30} g of boric acid (H ₃ BO ₃ , Boric acid), saccharin (C ₇₎ Solution containing 1.0 to _3.0 g of H ₄ NO ₃ SNa, Sodium Saccharin, 0.1 to 0.3 g of Sodium Lauryl Sulfate (C ₁₂ H ₂₅ O ₄ SNa, Sodium Chloride) to 20 to 40 g Is used as an electrolyte solution, the pH of the electrolyte solution is 2 to 3, the current density is 50 to 100mA / cm ² , the temperature of the electrolyte solution is 45 ~ 60 ℃ Ni wt% with a grain size of 5 ~ 15nm by the electroplating method A method for producing a Fe-Ni alloy having a 33 to 38%. 50 g of FeSO ₄ · 7H ₂ O (Ferrous Sulfate), 97 g of NiCl ₂ · 6H ₂ O (Nickel Chloride), 20-30 g of boric acid (H ₃ BO ₃ , Boric acid), saccharin (C ₇ H ₄₎ A solution containing 1.0 to 3.0 g of NO ₃ SNa, Sodium Saccharin, 0.1 to 0.3 g of sodium lauryl sulfate (C ₁₂ H ₂₅ O ₄ SNa, Sodium Chloride), and 20 to 40 g of sodium chloride (NaCl) Ni wt% of the electrolytic solution having a pH of 2 to 3, a current density of 50 to 100 mA / cm ² , and an electrolytic solution at a temperature of 45 to 60 ° C., having a grain size of 5 to 15 nm. A method for producing a Fe-Ni alloy having a 33 to 38%. Per 1 liter of water, 42 to 44 g of FeCl ₂ · 4H ₂ O (Ferrous Chloride), 97 g of NiSO ₄ · 6H ₂ O (Nickel Sulfate), 20-30 g of boric acid (H ₃ BO ₃ , Boric acid), saccharin (C ₇ Solution containing 1.0 to _3.0 g of H ₄ NO ₃ SNa, Sodium Saccharin, 0.1 to 0.3 g of Sodium Lauryl Sulfate (C ₁₂ H ₂₅ O ₄ SNa, Sodium Chloride) to 20 to 40 g Ni is used as an electrolyte solution, and the pH of the electrolyte solution is 2-3, the current density is 50-100 mA / cm ² , and the temperature of the electrolyte solution is 45 to 60 ° C. Process for producing Fe-Ni alloys with wt% of 33 to 38%. 44 to 50 g of FeCl ₂ · 4H ₂ O (Ferrous Chloride), 97 g of NiCl ₂ · 6H ₂ O (Nickel Chloride), _{20 to 30} g of boric acid (H ₃ BO ₃ , Boric acid), saccharin (C ₇₎ Solution containing 1.0 to _3.0 g of H ₄ NO ₃ SNa, Sodium Saccharin, 0.1 to 0.3 g of Sodium Lauryl Sulfate (C ₁₂ H ₂₅ O ₄ SNa, Sodium Chloride) to 20 to 40 g Ni is used as an electrolyte solution, and the pH of the electrolyte solution is 2-3, the current density is 50-100 mA / cm ² , and the temperature of the electrolyte solution is 45 to 60 ° C. Process for producing Fe-Ni alloys with wt% of 33 to 38%. Per liter of water, 35 to 37 g of FeSO ₄ · 7H ₂ O (Ferrous Sulfate), 97 g of Ni (NH ₂ SO ₃ ) ₂ (Nickel Sulfamate), _{20 to 30} g of boric acid (H ₃ BO ₃ , Boric acid), saccharin ( C ₇ H ₄ NO ₃ SNa, Sodium Saccharin (1.0-3.0g), Sodium Lauryl Sulfate (C ₁₂ H ₂₅ O ₄ SNa, Sodium Lauryl Sulfate) 0.1-0.3g, Sodium Chloride (NaCl, Sodium Chloride) 20-40g A solution to be used as an electrolytic solution, wherein the pH of the electrolyte solution is 2 to 3, the current density is 50 to 100 mA / cm ² , and the crystal grain size is 5 to 15 nm formed by electroplating in a state of 45 to 60 ° C. A process for producing a Fe-Ni alloy having a Ni wt% of 33 to 38%. 32 to 34 g of FeCl ₂ · 4H ₂ O (Ferrous Chloride), 97 g of Ni (NH ₂ SO ₃ ) ₂ (Nickel Sulfamate), 20 to 30 g of boric acid (H ₃ BO ₃ , Boric acid), saccharin C ₇ H ₄ NO ₃ SNa, Sodium Saccharin (1.0-3.0g), Sodium Lauryl Sulfate (C ₁₂ H ₂₅ O ₄ SNa, Sodium Lauryl Sulfate) 0.1-0.3g, Sodium Chloride (NaCl, Sodium Chloride) 20-40g A solution to be used as an electrolytic solution, wherein the pH of the electrolyte solution is 2 to 3, the current density is 50 to 100 mA / cm ² , and the temperature of the electrolyte solution is 45 to 60 ° C., and the grain size formed by the electroplating method is 5 to 15 nm. A process for producing a Fe-Ni alloy having a Ni wt% of 33 to 38%.