KR20100097575A - Iron foam and manufacturing method thereof - Google Patents

Abstract

PURPOSE: Iron foam and a manufacturing method thereof are provided to prevent the generation of pin holes on the iron foam surface by continuously removing organic components and remaining carbon. CONSTITUTION: Iron foam is formed of a net-shaped structure having open cells which comprise titanium 0.01~1 weight%, carbon 0.001~0.5 weight%, nickel 0.01~1 weight%, copper 0.01~1 weight%, and the rest iron and inevitable impurities. A method for manufacturing the iron foam comprises steps of: preparing an organic porous material, obtaining a conductive porous material by depositing titanium on the surface of the organic porous material, electro-plating iron on the surface of the conductive porous material, and heat-treating the conductive porous material to remove the organic porous components.

Description

Iron foam and its manufacturing method {IRON FOAM AND MANUFACTURING METHOD THEREOF}

The present invention relates to an iron foam and a method for manufacturing the same, and more particularly, to a method for continuously producing an iron foam having high ductility and high tensile strength using electroplating and an iron foam produced by this method.

Metal foam refers to a porous metal having many bubbles inside the metal material.

The metal foam is classified into an open cell type or a closed cell type according to the shape of bubbles contained therein. Open cells have bubbles in an interconnected shape that facilitate the passage of gas or fluid along these bubbles. On the other hand, in closed cells, bubbles are not connected to each other and exist independently, so that gas or fluid cannot be easily passed.

In the case of a metal foam having an open cell, the structure is similar to the bone of the human body, and thus the structure is stable, and it can be used for various purposes because of the physical feature that the surface area per unit volume is extremely large and lightweight.

Such metal foams are used in various industrial fields such as battery electrodes, fuel cell components, filters for soot filtration, pollution control devices, catalyst supports, and audio components.

Metal foams known to date are mainly known for metal foams based on nickel, copper, aluminum or silver, but not much for iron foams based on iron.

The present invention seeks to provide an iron foam in which pin-hole formation of the surface is suppressed as much as possible and excellent in ductility and tensile strength.

In another aspect, the present invention is to provide a method for depositing a metal having a strong corrosion resistance to a highly corrosive iron electroplating solution in the production of iron foam.

In another aspect, the present invention is to provide a method for producing an iron foam, so that in the iron electroplating process, divalent iron is oxidized to trivalent iron so that fine precipitates formed by trivalent iron hydroxide are not mixed in the iron plating layer.

In another aspect, the present invention is to provide a method for reducing the manufacturing cost by being able to continuously perform the electroplating process and heat treatment process in manufacturing the iron foam.

Iron foam according to an embodiment of the present invention is a network structure having an open cell, the structure is a weight%, the titanium content is 0.01% to 1%, the carbon content is 0.001% to 0.5%, The remainder includes iron foam with open cells made of iron and containing other unavoidable impurities.

Such iron foam structures may further contain a metal selected from 0.01% to 1% nickel and 0.01% to 1% copper.

According to an embodiment of the present invention, there is provided a method of manufacturing an iron foam, iii) preparing an organic porous body, ii) preparing a conductive porous body by depositing titanium (Ti) on the surface of the organic porous body, and iii) a conductive porous body. Ferrous chloride (FeCl ₂ · 4H ₂ O), at least one substance of malonic acid, ammonium chloride (NH ₄ Cl), vanadium trichloride (VCl ₃ ) is added, the pH is 0.5 Electroplating iron on the surface of the conductive porous body by passing through an iron electroplating solution of 2.5 to 2.5; and i) charging a conductive porous body plated with iron to a heat treatment furnace to remove the organic porous component.

In the conductive porous body preparation step, any one of nickel (Ni) and copper (Cu) may be further deposited.

In the case of mixing and depositing titanium (Ti) and nickel (Ni) during the preparation of the conductive porous body, the deposition rate may be 50 to 80% of titanium (Ti), 20 to 50% of nickel (Ni), and titanium (Ti). In the case of mixing and depositing copper and Cu, the deposition rate may be 50 to 80% of titanium (Ti) and 20 to 50% of copper (Cu).

The conductive porous preparation step may be deposited by a method of physical vapor deposition (PVD) in a roll-to-roll facility when titanium is deposited.

Metal deposition such as titanium is preferably deposited on the surface of the organic porous body at 0.02 µm to 0.3 µm.

The organic porous body used in one embodiment of the present invention is any one selected from a polymer foam, a nonwoven fabric, and an organic fabric, and it is preferable to use a polyurethane foam.

The iron electroplating solution may further include at least one of ferrous sulfate (FeSO ₄ · 7H ₂ O), nickel chloride (NiCl ₂ · 6H ₂ O), and copper chloride (CuCl ₂ · 2H ₂ O). Can be.

And iron electroplating it is preferable that the amount of temperature is 75 ℃ ~ 95 ℃ by plating apparent cathode current density of ^{100 A / m 2 ~ 1000A /} m 2 of.

The heat treatment step includes iii) removing the organic components in the iron foam, ii) removing residual carbon in the iron foam, iii) reducing heat treatment, and iii) removing the stress from the manufactured iron foam. do.

These heat treatment steps are preferably performed sequentially and sequentially in the tunnel furnace.

Iron foam prepared according to an embodiment of the present invention has a fine grain and good ductility, high tensile strength, such as battery electrodes, fuel cell components, soot filtration filter, pollution control device, catalyst support, audio components It can be applied to industrial fields.

The method for producing an iron foam according to an embodiment of the present invention can prevent the oxidation during iron plating can be continuously produced iron foam without breaking during winding.

Method for producing an iron foam according to an embodiment of the present invention can provide an oxidation atmosphere in the heat treatment process to prevent breakage of the iron foam due to the tensile force of the roll.

The method for manufacturing iron foam according to an embodiment of the present invention suppresses the formation of pinholes on the surface of the iron foam prepared by continuously removing organic components and residual carbon in a heat treatment process, and consequently provides a smooth surface iron foam. .

The iron foam manufacturing method according to an embodiment of the present invention enables to perform the deposition and plating process and the heat treatment process of the conductive metal continuously.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

In order to manufacture the iron foam, an organic porous body having a connection structure of bubbles to be formed inside the iron foam is prepared. As the organic porous body, various polymer foams, nonwoven fabrics, organic fabrics, and the like having bubbles connected therein may be used. One embodiment of the present invention illustrates that the polyurethane porous (PU) foam or an organic fabric is selected and used as such an organic porous body.

The organic porous body to be used as the substrate of the iron foam may be cut into sheets, and the cut sheets may be rounded to the cross section of the bubbles by chemical or thermal treatment. In addition, the organic porous sheet may optionally perform a pre-plating treatment necessary to smoothly perform plating such as cleaning treatment, acid treatment, catalyst coating, drying, and the like before the plating treatment. This process is to prepare an organic porous body.

Since the prepared organic porous body has little electrical conductivity, electrical conductivity must be given to plate iron on the surface of the organic porous body. This process is to prepare a conductive porous body.

Preparing the conductive porous body is prepared by a method of coating a conductive metal on the organic porous body in the form of a sheet.

Coating of the conductive metal on the surface of the organic porous body is performed by a roll to roll facility equipped with a physical vapor deposition (PVD) device. In a roll-to-roll installation, metals are deposited on both sides of the organic porous body. At this time, the metal deposited on the surface of the organic porous body is deposited by titanium (Ti) alone or by mixing titanium (Ti) and nickel (Ni) or titanium (Ti) and copper (Cu). The use of titanium or a titanium alloy as a PVD deposition source is to give strong corrosion resistance to the porous body. In addition, the coating of titanium on the surface of the organic porous body is because the iron electroplating solution described later is highly acidic and highly corrosive. That is, titanium has strong corrosion resistance with respect to the plating liquid which is strongly acidic.

When titanium (Ti) deposited on the surface of the organic porous body is deposited by mixing with nickel (Ni), the ratio is preferably 50 to 80% of titanium (Ti) and 20 to 50% of nickel (Ni). . In addition, when titanium (Ti) and copper (Cu) are mixed and deposited, the ratio of titanium (Ti) is 50 to 80%, and copper (Cu) is preferably controlled to 20 to 50%. This is because when the mixed deposition of other metals on the titanium, if the content of nickel (Ni) and copper (Cu) is controlled more than 50%, corrosion occurs in the electroplating process described later, it is difficult to obtain a uniform plating layer. If the content of nickel (Ni) and copper (Cu) is controlled to be lower than 20%, it is difficult to obtain a uniform plating layer because the conductivity improvement effect is lowered.

When the titanium (Ti) is deposited on the surface of the organic porous body alone or mixed with another metal, the thickness of the deposited metal layer is preferably 0.02 to 0.3 μm. If the thickness of the deposited metal is less than 0.02㎛ the electroplating may be non-uniform, if it is thicker than 0.3㎛ the porous body may be deformed due to the internal heat of the deposition equipment.

Next, as described above, the porous metal coated with the conductive metal is electroplated in an electroplating bath containing iron.

The electroplating solution used for electroplating iron contains ferrous chloride (FeCl ₂ · 4H ₂ O) and the pH is adjusted to 0.5-2.5. At this time, the ferrous chloride contained in the electroplating solution is preferably added in 30 ~ 450g / L, it may optionally include 50 ~ 350g / L ferrous sulfate (FeSO ₄ · 7H ₂ O). .

At least one or more of malonic acid 1 ~ 10g / L, ammonium chloride (NH ₄ Cl) 30 ~ 150g / L, vanadium trichloride (VCl ₃ ) 0.1 ~ 2g / L to improve the antioxidant properties in such a plating solution Substances can be added further. Antioxidant is a property that inhibits the oxidation of ferric iron to trivalent iron. Malonic acid and ammonium chloride serve this function. The addition of vanadium trichloride further improves the antioxidant properties. Ammonium chloride also serves to increase ductility in the iron foams produced in addition to its antioxidant properties.

In the case of depositing titanium (Ti) alone on an organic porous body, nickel chloride (NiCl ₂ ㆍ 6H ₂ O) 1 ~ 10 g / L and copper chloride (CuCl ₂ ㆍ 2H ₂ O) 5 ~ At least one of 50 mg / L may be added to the iron plating solution.

As described above, the pH of the electroplating solution is preferably adjusted to 0.5 to 2.5. This is because when the pH of the plating liquid is less than 0.5, the solubility of the low carbon steel as the cathode material is increased by the plating liquid, and when the pH of the plating liquid is higher than 2.5, it is difficult to suppress the formation of trivalent iron. If trivalent iron is produced, the ductility of the iron foam becomes worse and cannot be wound.

When iron is plated on the conductive porous body in an electroplating facility, the conductive porous body to be plated is used as the cathode, and the plating source is iron (Fe) as the anode. At this time, titanium (Ti) is deposited on the surface of the porous material, which is a negative electrode material, or titanium (Ti) and nickel (Ni) or titanium (Ti) and copper (Cu) are mixed and deposited. And as a positive electrode material, it is preferable to use low carbon steel whose carbon content is 0.1% or less.

When electroplating iron on the conductive porous body under the above conditions, the electrolytic conditions of the electroplating bath are the apparent cathode current density is 100 ~ 1000A / m ² and the temperature of the plating solution is 75 ~ 95 ℃. In this case, when the plating solution temperature is lower than 75 ° C., the surface of the plated conductive porous body becomes black and the ductility deteriorates easily. And if the plating liquid temperature is higher than 95 ℃ energy consumption is a lot and the plating liquid is evaporated too much.

After the iron is plated on the surface of the conductive porous body under the conditions described above, the conductive porous body coated with iron is used to remove organic materials and perform the following heat treatment to give ductility and tensile strength to the formed iron foam.

In more detail, the heat treatment step is performed by first removing the organic porous body from the iron-plated porous body and then removing carbon that may remain in the iron foam after the heat treatment. Subsequently, heat treatment is performed in a reducing atmosphere to reduce iron, and stress relief annealing is continuously performed to secure ductility and tensile strength in the manufactured iron foam. The heat treatment as described above is preferably carried out sequentially by placing the tunnel furnace continuously. At this time, the atmosphere to the tunnel for heat treatment maintains an inert state and the inert gas used may be nitrogen (N ₂ ) or argon (Ar) gas. Hereinafter, the heat treatment step will be described in detail.

First, in order to remove organic components, such as polyurethane, from the electroplated iron porous porous body, the electroconductive porous body electroplated with iron is charged to a tunnel type furnace. At this time, the atmosphere in the tunnel is an inert atmosphere or a hydrogen gas atmosphere diluted with an inert gas, and the temperature is maintained at 500 ° C to 600 ° C by heating from room temperature. As such, the conductive porous body plated with iron is maintained in the tunnel furnace maintained at the atmosphere and the temperature within 10 minutes to 60 minutes, and then cooled to 100 ° C. or less to remove the organic components inside the iron foam. As such, when the organic component is removed from the conductive porous body, it has a shape of an iron foam.

Iron foam from which organic components have been removed is continuously charged into a tunnel-type oxidation furnace to remove carbon remaining in the iron foam. At this time, the atmosphere of the tunnel-type oxidation furnace is maintained in a state in which oxygen (O ₂ ) gas is diluted with an inert gas. At this time, the content of oxygen is preferably maintained at 3% or less. The tunnel-type oxidation furnace with iron foam is heated to maintain the temperature in the furnace at 500 ° C. or higher and 600 ° C. or lower. In this manner, the iron foam is kept in the tunnel for 10 minutes or more and 30 minutes or less and then cooled to 100 ° C or less. This heat treatment is to prevent the oxidized iron foam is damaged by the tensile force of the roll in the continuous oxidizing heat treatment process. In addition, it is possible to smoothly maintain the surface of the iron foam while maintaining excellent ductility and tensile strength by suppressing the formation of pin-holes that may be formed in the iron foam when the organic component is removed from the oxidizing atmosphere. .

In addition, the process of removing carbon remaining in the iron foam by charging the tunnel-type oxidation furnace is a process required to reduce the carbon content of the final iron foam product, and the carbon content is 0.05% or less. Can be reduced. In this case, the tensile strength and elongation of the final iron foam product can be increased. However, the above process may be omitted, in which case the tensile strength and elongation of the final iron foam product indicates the degree of usability as iron foam, the carbon content is about 0.2 ~ 0.5%.

As described above, heat treatment is performed to remove the organic component and the carbon component from the conductive porous body, followed by a reduction heat treatment process. Reduction heat treatment is performed in a tunnel furnace in which hydrogen (H ₂ ) gas is diluted with an inert gas. In this case, the tunnel-type reduction furnace is charged with oxidized iron foam in a state where the temperature is raised to 1150 ° C. or more and 1150 ° C. or less, and maintained at 10 minutes or more and 60 minutes or less. Then, in order to remove the internal stress that may occur during the cooling process, it is cooled to a temperature range of 400 ° C. or higher and 600 ° C. or lower, and then maintained at that temperature for 10 minutes or more and 60 minutes or less and then cooled to 100 ° C. or lower.

As described above, the step of producing the final iron foam by the various steps of the organic porous body is preferably carried out continuously in a sheet state in a facility arranged continuously. To this end, the conductive porous body manufacturing process uses a roll-to-roll facility, and the electroplating and heat treatment process preferably uses a plating facility and a tunnel furnace that can continuously pass the sheet wound on the roll.

Iron foam produced by the above process is made of a network structure having an open cell as shown in FIG.

The structure of the iron foam prepared according to an embodiment of the present invention is by weight, titanium content of 0.01% to 1%, carbon content of 0.001% to 0.5%, the rest is made of iron and other unavoidable impurities It is contained.

In addition, the structure of the iron foam prepared according to an embodiment of the present invention may further contain a metal selected from 0.01% to 1% nickel and 0.01% to 1% copper in addition to containing titanium and carbon.

And when iron and nickel are deposited together, the content of titanium and nickel is 50 to 80% titanium, 20 to 50% nickel, and when titanium and copper are deposited together, the content of titanium and copper is titanium It is 50 to 80%, and it is preferable that it is 20 to 50% of copper.

Hereinafter, the present invention will be described in more detail with reference to Examples. These examples are merely to illustrate the invention and the invention is not limited thereto.

Example

First, polyurethane foam was used as a starting material for producing the iron foam. The polyurethane foam used had a thickness of 1.7 mm and an average diameter of holes of 575 µm.

The prepared polyurethane foam was subjected to basic pretreatment, and titanium (Ti), titanium-nickel (Ti-Ni) and titanium-copper (Ti-Cu) were deposited by a PVD apparatus installed in a roll-to-roll facility.

Therefore, hereinafter, the present embodiment will be described in the order of titanium (Ti), titanium-nickel (Ti-Ni) and titanium-copper (Ti-Cu).

1. Titanium (Ti) Deposition Example

Example A1 to Example A4

A conductive porous body was prepared by depositing titanium to 0.05 μm on the prepared polyurethane foam. The conductive porous body was electroplated with iron as shown in Table 1 in an electroplating bath having a composition as shown in Table 1 below.

When electroplating iron, the electrolytic condition of the plating bath was an apparent cathode current density of 700 A / m ² , the temperature and pH of the plating solution is shown in Table 1. The surface densities of the plated conductive porous bodies were all 420 g / m ² .

The electro-plated conductive porous body was placed in a tunnel furnace, and heated to 600 ° C. under an inert atmosphere in which nitrogen (N ₂ ) gas was injected. It was.

After removing the organic components such as polyurethane inside the iron foam, the iron foam from which the organic components have been removed is placed in a tunnel furnace, and mixed with 97% nitrogen (N ₂ ) and 3% oxygen (O ₂ ) gas. Charged into a tunnel-type oxidation furnace into which gas was injected. At this time, the temperature of the tunnel-type oxidation furnace was heated to 600 ℃ to maintain for 10 minutes and then cooled to 100 ℃ or less to remove the carbon (carbon).

Then, the iron foam was charged to the tunnel-type reduction furnace, the temperature was raised to 1050 ° C., and the temperature was maintained for 20 minutes to heat-treat the iron foam in a reducing atmosphere. At this time, the reducing atmosphere was maintained such that a mixed gas of 97% nitrogen (N ₂ ) and 3% hydrogen (H ₂ ) gas was injected.

The iron foam subjected to the reduction heat treatment in the reducing atmosphere as described above was cooled from 1050 ° C. to 600 ° C. in order to remove internal stress that may be generated during the cooling process, and then maintained at 600 ° C. for 20 minutes and then cooled to room temperature.

Example A5

A conductive porous body was prepared by depositing titanium to a thickness of 0.15 μm on the prepared polyurethane foam. The conductive porous body was electroplated with iron in an electroplating bath having a composition as shown in Table 1 below.

When electroplating iron, the electrolytic condition of the plating bath was an apparent cathode current density of 700 A / m ² , the temperature and pH of the plating solution is shown in Table 1. The surface densities of the plated conductive porous bodies were all 420 g / m ² .

The electroplated conductive porous body was placed in the tunnel furnace, and the temperature of the tunnel furnace where the mixed gas of 97% nitrogen (N ₂ ) and 3% hydrogen (H ₂ ) gas was injected was raised to 520 ° C. at room temperature for 30 minutes. It was kept and then cooled to 100 ° C or lower.

After removing the organic components such as polyurethane inside the iron foam, the iron foam from which the organic components have been removed is placed in a tunnel furnace, and mixed with 97% nitrogen (N ₂ ) and 3% oxygen (O ₂ ) gas. Charged into a tunnel-type oxidation furnace into which gas was injected. In this case, the temperature of the tunnel-type oxidation furnace was maintained at 550 ° C. for 20 minutes, and then cooled to 100 ° C. or lower to remove residual carbon.

The oxidized iron foam was then charged to a tunnel-type reduction furnace, and the furnace atmosphere was maintained such that a mixed gas of 97% nitrogen (N ₂ ) and 3% hydrogen (H ₂ ) gas was injected. At this time, the temperature of the tunnel-type oxidation furnace was raised to 1000 ℃ and maintained for 30 minutes.

The iron foam subjected to reduction heat treatment in the reducing atmosphere as described above was cooled to 500 ° C. for 30 minutes to remove internal stress that may be generated during the cooling process, and then cooled to 100 ° C. or lower to produce iron foam.

Example A6

A conductive porous body was prepared by depositing titanium to a thickness of 0.25 μm on the prepared polyurethane foam. The conductive porous body was electroplated with iron in an electroplating bath having a composition as shown in Table 1 below.

When electroplating iron, the electrolytic conditions of the plating bath had an apparent cathode current density of 800 A / m ² , and the temperature and pH of the plating solution are shown in Table 1. The surface densities of the plated conductive porous bodies were all 418 g / m ² .

Thereafter, the heat treatment process was performed in the same manner as in Example A1.

Example A7

A conductive porous body was prepared by depositing titanium to a thickness of 0.3 μm on the prepared polyurethane foam.

When electroplating iron, the electrolytic conditions of the plating bath had an apparent cathode current density of 500 A / m ² , and the temperature and pH of the plating solution are shown in Table 1. The surface densities of the plated conductive porous bodies were all 418 g / m ² .

Thereafter, the heat treatment process was performed in the same manner as in Example A1.

Example A8

A conductive porous body was prepared by depositing titanium to a thickness of 0.18 μm on the prepared polyurethane foam. The conductive porous body was electroplated with iron in an electroplating bath having a composition as shown in Table 1 below.

When electroplating iron, the electrolytic condition of the plating bath was an apparent cathode current density of 700 A / m ² , the temperature and pH of the plating solution is shown in Table 1. The surface densities of the plated conductive porous bodies were all 420 g / m ² .

The electroplated conductive porous body was placed in the tunnel furnace, and the temperature of the tunnel furnace where the mixed gas of 97% nitrogen (N ₂ ) and 3% hydrogen (H ₂ ) gas was injected was raised to 600 ° C. at room temperature for 30 minutes. It was kept and then cooled to 100 ° C or lower.

The iron foam was then charged to a tunnel-type reduction furnace, and the furnace atmosphere was maintained so that a mixed gas of 97% nitrogen (N ₂ ) and 3% hydrogen (H ₂ ) gas was injected. At this time, the temperature of the tunnel-type oxidation furnace was raised to 1050 ° C and maintained for 30 minutes.

The iron foam subjected to reduction heat treatment in the reducing atmosphere as described above was cooled to 500 ° C. for 30 minutes to remove internal stress that may be generated during the cooling process, and then cooled to 100 ° C. or lower to produce iron foam.

Comparative Example B1 to Comparative Example B7

A conductive porous body was prepared by depositing titanium to 0.2 μm on the prepared polyurethane foam. The conductive porous body was electroplated with iron as shown in Table 1 in an electroplating bath having a composition as shown in Table 1 below.

When electroplating iron, the electrolytic condition of the plating bath was an apparent cathode current density of 700 A / m ² , the temperature and pH of the plating solution is shown in Table 1. The surface densities of the plated conductive porous bodies were all 420 g / m ² .

As can be seen in Table 1, Comparative Example B1 and Comparative Example B3 have the same composition as Example A1 and Example A3 and the electroplating solution, but Comparative Example B1 has a difference in low plating temperature, and Comparative Example B3 has a low pH. There is a difference and the rest of the conditions are the same as in Example A1 and Example A3.

Comparative Example B2 differs in that no malonic acid is added in the composition of Example A2 and the plating solution, and the remaining conditions are the same as those of Example A2.

In Comparative Example B4, nickel chloride (NiCl ₂ .6H ₂ O) was not added in the composition of Example A4 and the plating solution, and the rest of the conditions were the same as in Example A4.

In addition, Comparative Example B5 is mostly the same as Example A5 and differs in the following heat treatment conditions. That is, the plated conductive porous body was placed in a tunnel furnace, and heated to room temperature from 520 ° C. in an inert atmosphere in which nitrogen (N ₂ ) gas was injected, and then maintained at that temperature for 30 minutes to prepare an iron foam from which the polyurethane component was removed.

After removing the organic components such as polyurethane inside the iron foam, the iron foam from which the organic components have been removed is placed in a tunnel furnace, and mixed with 97% nitrogen (N ₂ ) and 3% oxygen (O ₂ ) gas. Charged into a tunnel-type oxidation furnace into which gas was injected. In this case, the temperature of the tunnel-type oxidation furnace was maintained at 550 ° C. for 20 minutes, and then cooled to 100 ° C. or lower to remove residual carbon.

Then, the iron foam was charged to the tunnel-type reduction furnace, the temperature was raised to 1000 ° C., and then maintained at that temperature for 30 minutes to heat-treat the iron foam in a reducing atmosphere. At this time, the reducing atmosphere is the same as in Example A1. And the high temperature heat-treated iron foam was directly cooled from 1000 ℃ to room temperature. That is, no annealing was performed to remove the stress.

Comparative Example B6 is mostly the same as Example A6 and differs in the following heat treatment conditions. That is, the plated conductive porous body was placed in a tunnel-type kiln in which air was injected, and the temperature was raised from room temperature to 600 ° C., and then maintained at that temperature for 10 minutes to prepare an oxidized iron foam from which the polyurethane component was removed.

Comparative Example B7 is mostly the same as Example A6 and differs in the following heat treatment conditions. That is, the plated conductive porous body was placed in a tunnel furnace, and the iron foam was removed from the polyurethane component by raising the temperature from room temperature to 520 ° C. in an inert atmosphere in which nitrogen (N ₂ ) gas was injected and maintaining the temperature for 30 minutes.

After removing the organic components such as polyurethane inside the iron foam, the iron foam from which the organic components have been removed is placed in a tunnel furnace, and mixed with 97% nitrogen (N ₂ ) and 3% oxygen (O ₂ ) gas. Charged into a tunnel-type oxidation furnace into which gas was injected. In this case, the temperature of the tunnel-type oxidation furnace was maintained at 650 ° C. for 20 minutes, and then cooled to 100 ° C. or lower to remove residual carbon.

division Ferrous Chloride (g / L) Ferrous Sulfate (g / L) Chloride
Ammonium (g / L) Nickel Chloride (g / L) Copper Chloride (mg / L) Malonic acid (g / L) Vanadium trichloride (g / L) Plated
Temperature
(℃) pH Example A1 420 - - 2 - 2.2 0.2 81 2.5 Example A2 440 - - One - 6.0 - 83 0.5 Example A3 75 350 - - 17 3.7 - 87 1.7 Example A4 85 330 - 5 - 3.3 - 90 1.0 Example A5 420 65 - 4 - 2.0 - 85 2.3 Example A6 430 - - - 14 2.8 0.3 93 1.5 Example A7 50 280 36 4 - 6.0 - 93 0.7 Example A8 400 60 34 3 - 3.4 - 89 0.8 Comparative Example B1 420 - - 2 - 2.2 0.2 70 2.5 Comparative Example B2 440 - - One - - - 83 0.5 Comparative Example B3 75 350 - - 17 3.7 - 87 2.8 Comparative Example B4 85 330 - - - 3.3 - 90 1.0 Comparative Example B5 420 65 - 4 - 2.0 - 85 2.3 Comparative Example B6 430 - - - 14 2.8 0.3 93 1.5 Comparative Example B7 50 280 36 4 - 6.0 - 93 0.7

Iron foam prepared according to the process of the present embodiment as described above to measure the elongation and tensile strength to investigate the physical properties. The physical properties of these iron foams were measured using a tensile compression tester.

And when manufactured by the continuous process to measure the winding degree of the iron foam sheet was measured the minimum winding diameter at the time of winding, this minimum winding diameter was measured in the state after the electroplating and heat treatment.

The measurement of this minimum winding diameter was expressed as the diameter of the iron foam when it was wound without cracking in a cylinder having a diameter (Φ) of 30 to 150 mm. And when the iron foam is cracked when winding the iron foam was marked as "unwinding".

The physical properties and winding diameters of the iron foam thus measured are shown in Table 2 below.

Elongation (%) Tensile Strength (N / ㎠) Minimum winding diameter after plating (mm) Minimum winding diameter after heat treatment (mm) Remarks Example A1 11.2 38.2 Φ50 Φ30 Example A2 12.9 32.4 Φ50 Φ30 Example A3 13.3 34.1 Φ50 Φ30 - Example A4 13.0 38.4 Φ50 Φ30 - Example A5 13.4 37.2 Φ50 Φ30 - Example A6 13.2 36.4 Φ50 Φ30 - Example A7 13.3 35.1 Φ50 Φ30 - Example A8 13.6 35.7 Φ50 Φ30 - Comparative Example B1 - - Unwinding Unwinding - Comparative Example B2 - - Unwinding Unwinding - Comparative Example B3 - - Unwinding Unwinding - Comparative Example B4 4.3 23.2 Φ150 Φ80 Non-uniform plating Comparative Example B5 3.1 74.8 Φ50 Φ150 Hardness increase Comparative Example B6 - - Φ50 Φ150 Partial iron foam broken Comparative Example B7 1.2 18.7 Φ50 Φ100 Pinhole generation

As shown in Table 2 showing the results of this example, it can be seen that all of the examples exhibited excellent elongation and high tensile strength and were well wound without winding in winding the iron form in the sheet state after plating or after heat treatment.

However, in the case of the comparative example, even if the physical properties of the prepared iron foam is poor or good physical properties, abnormalities occurred in winding the iron foam after plating or after heat treatment. The cause will be described below.

Experimental results of Comparative Examples B1 to B6

In Comparative Example B1, the plating solution temperature was lower than 75 ° C. Therefore, the ductility of the iron foam was bad, and the iron foam in the sheet state could not be wound.

In Comparative Example B2, the antioxidant malonic acid was not added to the plating liquid. Therefore, trivalent iron was generated in the plating process, resulting in poor ductility of the iron foam. For this reason, the iron foam in the sheet state could not be wound.

In Comparative Example B3, the plating liquid pH was higher than 2.5. Therefore, trivalent iron was generated in the plating process, resulting in poor ductility of the iron foam. For this reason, the iron foam in the sheet state could not be wound.

In Comparative Example B4, either of nickel chloride (NiCl ₂ · 6H ₂ O) or copper chloride (CuCl ₂ · 2H ₂ O) added to improve the conductivity of the plating solution was not added, resulting in uneven plating. However, although the minimum winding diameter falls somewhat, winding is possible.

In Comparative Example B5, the heat treatment conditions were quenched to room temperature after the reduction heat treatment. Therefore, the hardness of the iron foam was increased, resulting in a slight drop in the minimum winding diameter after heat treatment.

In Comparative Example B6, a heat treatment was performed to remove organic components in an atmosphere of air. In the subsequent process, the tensile strength of the roll was reduced, and a part of the iron foam was broken, but the iron foam in the broken state could be used. .

In Comparative Example B7, the temperature of the oxidation process for removing residual carbon was higher than 600 ° C. As a result, many pinholes were generated on the surface of the iron foam, resulting in a slight drop in the minimum winding diameter after heat treatment.

On the other hand, Figure 1 is a SEM photograph taken after manufacturing the iron foam by heat-treating the plated conductive porous body prepared according to Example A1 of the present invention, Figure 2 is an SEM photograph taken to enlarge the surface of the iron foam of FIG.

Referring to Figures 1 and 2, it can be seen that the surface of the iron foam prepared according to the embodiment of the present invention has no projections and smooth and no cracks.

However, in the case of the plated conductive porous body prepared according to Comparative Example B1 of the present invention as shown in FIG. 3, it can be seen that many protrusions are generated on the surface of the iron foam prepared, resulting in nonuniformity and many cracks. Therefore, it was almost impossible to wind up after electroplating the iron foam.

2. Titanium-Ni (Ti-Ni) Deposition Examples

Example C1 to Example C2

Titanium and nickel were deposited together on the prepared polyurethane foam.

In Example C1, a mixed deposition ratio of titanium and nickel was deposited at 5: 5, and the deposited layer of titanium and nickel had a thickness of 0.17 μm. The rest of the experimental conditions were the same as in Example A5 except that nickel chloride (g / L) was not added.

In Example C2, a mixed deposition ratio of titanium and nickel was deposited at 7: 3, and the deposited layer of titanium and nickel had a thickness of 0.2 μm. The rest of the experimental conditions were the same as in Example A7 except that nickel chloride (g / L) was not added.

On the other hand, in Comparative Example D1, the mixed deposition ratio of titanium and nickel was deposited at 4: 6, and the thickness of the deposited titanium and nickel mixed layer was 0.17 μm. The rest of the experimental conditions were the same as in Example A6 except that copper chloride (g / L) was not added.

In Comparative Example D2, the mixed deposition ratio of titanium and nickel was deposited at 9: 1, and the thickness of the deposited titanium and nickel mixed layer was 0.2 μm. The rest of the experimental conditions were the same as in Example A5 except that nickel chloride (g / L) was not added.

Table 3 below shows experimental conditions of Examples and Comparative Examples.

Ferrous Chloride (g / L) Ferrous Sulfate (g / L) Chloride
Ammonium (g / L) Nickel Chloride (g / L) Copper Chloride (mg / L) Malonic acid (g / L) Vanadium trichloride (g / L) Plated
Temperature pH Example C1 420 65 - - - 2.0 - 85 ℃ 2.3 Example C2 50 280 36 - - 6.0 - 93 ℃ 0.7 Comparative Example D1 430 - - - - 2.8 0.3 93 ℃ 1.5 Comparative Example D2 420 65 - - - 2.0 - 85 ℃ 2.3

The physical properties and winding diameters of the iron foam prepared by using the titanium-nickel deposition layer thus tested are shown in Table 4 below.

Elongation (%) Tensile Strength (N / ㎠) Minimum winding diameter after plating (mm) Minimum winding diameter after heat treatment (mm) Remarks Example C1 12.9 36.2 Φ50 Φ30 - Example C2 13.1 35.8 Φ50 Φ30 - Comparative Example D1 - - Unwinding Unwinding Non-uniform plating Comparative Example D2 - - Unwinding Unwinding Non-uniform plating

As shown in Table 4 showing the results of this embodiment, all of the examples show excellent elongation and high tensile strength, and it can be seen that the coils are well wound without any break in winding the iron form in the sheet state after plating or after heat treatment.

However, in the case of depositing by mixing titanium and nickel as in Comparative Example, even if the physical properties of the prepared iron foam is poor or good physical properties, the abnormality occurred in winding the iron foam after plating or after heat treatment.

In the case of Comparative Example D1, since the ratio of nickel is greater than 5 in the mixed deposition ratio of titanium and nickel, nickel is corroded during electroplating, resulting in uneven plating, and thus winding is impossible. In the case of Comparative Example D2, since the ratio of nickel in the mixed deposition ratio of titanium and nickel was lower than 2, the conductivity improvement effect was reduced, so that it was difficult to obtain a uniform plating layer, and thus winding was impossible.

3. Titanium-Cu Deposition Examples

Example E1 to Example E2

Titanium and copper were deposited together on the prepared polyurethane foam.

In Example E1, a mixed deposition ratio of titanium and copper was deposited at 5: 5, and the deposited layer of titanium and copper had a thickness of 0.17 μm. The rest of the experimental conditions were the same as in Example A5 except that nickel chloride (g / L) was not added.

In Example E2, the mixed deposition ratio of titanium and copper was deposited at 7: 3, and the deposited layer of titanium and copper had a thickness of 0.2 μm. The rest of the experimental conditions were the same as in Example A7 except that nickel chloride (g / L) was not added.

On the other hand, in Comparative Example F1, the deposition ratio of titanium and copper was deposited at 4: 6, and the deposited layer of titanium and copper had a thickness of 0.17 μm. The rest of the experimental conditions were the same as in Example A6 except that copper chloride (g / L) was not added.

In Comparative Example F2, the mixed deposition ratio of titanium and copper was deposited at 9: 1, and the deposited layer of titanium and copper had a thickness of 0.2 μm. The rest of the experimental conditions were the same as in Example A5 except that nickel chloride (g / L) was not added.

Table 5 below shows experimental conditions of Examples and Comparative Examples.

Ferrous Chloride (g / L) Ferrous Sulfate (g / L) Chloride
Ammonium (g / L) Nickel Chloride (g / L) Copper Chloride (mg / L) Malonic acid (g / L) Vanadium trichloride (g / L) Plated
Temperature pH Example E1 420 65 - - - 2.0 - 85 ℃ 2.3 Example E2 50 280 36 - - 6.0 - 93 ℃ 0.7 Comparative Example F1 430 - - - - 2.8 0.3 93 ℃ 1.5 Comparative Example F2 420 65 - - - 2.0 - 85 ℃ 2.3

The physical properties and winding diameters of the iron foam prepared using the titanium-copper deposited layer thus tested are shown in Table 6 below.

Elongation (%) Tensile Strength (N / ㎠) Minimum winding diameter after plating (mm) Minimum winding diameter after heat treatment (mm) Remarks Example E1 12.7 35.8 Φ50 Φ30 - Example E2 12.8 36.2 Φ50 Φ30 - Comparative Example F1 - - Unwinding Unwinding Non-uniform plating Comparative Example F2 - - Unwinding Unwinding Non-uniform plating

As shown in Table 6 showing the results of this embodiment, all of the examples show excellent elongation and high tensile strength, and it can be seen that the coils are well wound without winding in winding the sheet of iron foam even after plating or after heat treatment.

However, in the case of depositing by mixing titanium and copper as in Comparative Example, even if the physical properties of the prepared iron foam is poor or good physical properties, the abnormality occurred in winding the iron foam after plating or after heat treatment.

In the case of Comparative Example F1, since the ratio of copper in the mixed deposition ratio of titanium and copper is larger than 5, copper was corroded at the time of electroplating, resulting in uneven plating, and thus winding was impossible. In Comparative Example F2, since the ratio of copper in the mixed deposition ratio of titanium and copper was lower than 2, the effect of improving the conductivity was inferior, and it was difficult to obtain a uniform plating layer, and thus winding was impossible.

 Although the embodiments of the present invention have been described above, the scope of the present invention is not limited thereto, and various modifications and changes can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. Naturally, it is within the scope of the present invention.

Figure 1 is a SEM photograph taken after the iron conductive plate prepared by heat-treating the plated conductive porous body prepared according to Example A1 of the present invention.

FIG. 2 is an enlarged SEM photograph of the surface of the iron foam of FIG.

Figure 3 is a SEM photograph before the heat treatment step of the plated conductive porous body prepared according to Comparative Example B1 of the present invention

Claims (22)

A network structure having open cells, the structure in weight percent, An iron foam having an open cell containing from 0.01% to 1% of titanium, from 0.001% to 0.5% of carbon, the remainder being iron and containing other unavoidable impurities. In claim 1, The structure is an iron foam having an open cell further containing a metal selected from 0.01% to 1% nickel and 0.01% to 1% copper. In claim 2, When the structure contains titanium (Ti) and nickel (Ni), the content thereof is 50 to 80% of titanium (Ti), 20 to 50% of nickel (Ni), and titanium (Ti) and copper (Cu). Iron foam having open cells of 50 to 80% titanium (Ti) and 20 to 50% copper (Cu). Preparing an organic porous body; and Preparing a conductive porous body by depositing titanium (Ti) on the surface of the organic porous body; Wow The conductive porous body includes ferrous chloride (FeCl ₂ · 4H ₂ O), at least one material of malonic acid, ammonium chloride (NH ₄ Cl), vanadium trichloride (VCl ₃ ) is added, electroplating iron on the surface of the conductive porous body through an iron electroplating solution having a pH of 0.5 to 2.5; And A heat treatment step of removing the organic porous body component by charging the iron-coated conductive porous body to a heat treatment furnace Method for producing an iron foam containing. In claim 4, The conductive porous body preparation step is a method of manufacturing an iron foam to further deposit any one metal of nickel (Ni) and copper (Cu). In claim 5, In the conductive porous preparation step, when titanium (Ti) and nickel (Ni) are mixed and deposited, the deposition rate is 50 to 80% of titanium (Ti) to 20 to 50% of nickel (Ni), and titanium (Ti) and copper When (Cu) is mixed and deposited, the deposition rate is 50 to 80% of titanium (Ti) versus 20 to 50% of copper (Cu). In claim 4, The conductive porous body preparing step is a method of manufacturing iron foam deposited by a method of physical vapor deposition (PVD) in a roll-to-roll facility. In claim 7, The deposition is a method of manufacturing the iron foam to be deposited in the porous body at 0.02㎛ to 0.3㎛. In claim 4, The organic porous body is any one selected from polymer foam, non-woven fabric, organic fabrics. In claim 9, The organic porous body is any one selected from the group consisting of polyurethane foam and porous organic fabric iron foam. In any one of claims 4 to 10 The iron electroplating solution further includes at least one of ferrous sulfate (FeSO ₄ · 7H ₂ O), nickel chloride (NiCl ₂ · 6H ₂ O), and copper chloride (CuCl ₂ · 2H ₂ O). Method for producing iron foam. In paragraph 11 The iron electroplating solution is ferrous chloride 30 ~ 450g / L, ferrous sulfate (FeSO ₄ · 7H ₂ O) is 50 ~ 350g / L, nickel chloride (NiCl ₂ · 6H ₂ O) is 1 - to 10g / L, copper chloride (CuCl ₂ and 2H ₂ O) the method of manufacturing an iron form to be added to the 5 ~ 50mg / L. In any one of claims 4 to 10 The iron electroplating solution is added to malonic acid (malonic acid) 1 ~ 10g / L, ammonium chloride (NH ₄ Cl) 30 ~ 150g / L, vanadium trichloride (VCl ₃ ) is added at 0.1 ~ 2g / L Method of making iron foam. In claim 12 The iron electroplating solution is added to malonic acid (malonic acid) 1 ~ 10g / L, ammonium chloride (NH ₄ Cl) 30 ~ 150g / L, vanadium trichloride (VCl ₃ ) is added at 0.1 ~ 2g / L Method of making iron foam. In any one of claims 4 to 10 The iron electroplating solution is a temperature of 75 ℃ ~ 95 ℃ manufacturing method of iron foam. In paragraph 11 The iron electroplating solution is a temperature of 75 ℃ ~ 95 ℃ manufacturing method of iron foam. In any one of claims 4 to 10 In the electroplating step, the cathode current density plating an apparent set of ^{100 A / m 2 ~ 1000A /} m 2 The method of producing a ferrous form. In any one of claims 4 to 10 In the heat treatment step, the plated conductive porous body is placed in a tunnel furnace, and an inert gas or an inert gas in which hydrogen gas is diluted is injected into the tunnel furnace, and the temperature is raised from 500 ° C to 600 ° C to 10 minutes to 60 minutes. After maintaining, cooling to 100 ℃ or less to remove the organic components inside the iron foam manufacturing method. In paragraph 18 In the heat treatment step, the iron foam from which the organic components have been removed is placed in a tunnel oxidation furnace, and an inert gas diluted with oxygen gas is injected into the tunnel oxidation furnace to maintain a temperature of 10 minutes to 30 minutes by raising the temperature to 500 ° C to 600 ° C. And then cooling to less than 100 ℃ manufacturing method of iron foam further comprising the step of removing the remaining carbon (carbon). In claim 18, In the heat treatment step, the iron foam from which the organic components have been removed is placed in a tunnel type reduction furnace, and hydrogen (H ₂ ) gas diluted with an inert gas is injected into the tunnel type reduction furnace to raise the temperature to 950 ° C. to 1150 ° C. or less. After the high temperature heat treatment in a reducing atmosphere by maintaining a minute to 60 minutes, and then cooled to a temperature range of 400 ℃ ~ 600 ℃ or less, and maintaining at 10 ~ 60 minutes or less at that temperature and then cooling to 100 ℃ or less Method of making iron foam. In claim 19, The iron foam from which the residual carbon was removed in the heat treatment step was placed in a tunnel type reduction furnace, and hydrogen (H ₂ ) gas diluted with an inert gas was introduced into the tunnel type reduction furnace to raise the temperature to 950 ° C. to 1150 ° C. or less. After the high temperature heat treatment in a reducing atmosphere by maintaining a minute to 60 minutes, and then cooled to a temperature range of 400 ℃ ~ 600 ℃ or less, and maintaining at 10 ~ 60 minutes or less at that temperature and then cooling to 100 ℃ or less Method of making iron foam. In any one of claims 4 to 10 The iron foam manufacturing method is characterized in that the continuous production method.

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