KR20200015357A - Iron-copper alloy material coated with copper and method for manufacturing the same - Google Patents

Abstract

The present invention relates to a copper-coated iron-copper alloy material, which comprises iron-copper (Fe-Cu) alloy and a copper layer formed on the surface of the iron-copper alloy, and a manufacturing method thereof. According to one embodiment, the copper layer is formed through self-coating by high-temperature heat treatment of the iron-copper alloy. According to the present invention, the iron-copper (Fe-Cu) alloy is used as a main body, and copper (Cu) is coated on the surface of the iron-copper (Fe-Cu) alloy through high-temperature heat treatment, and therefore provided are excellent mechanical properties, economical efficiency, etc. along with high electrical conductivity.

Description

Copper-coated iron-copper alloy and its manufacturing method {IRON-COPPER ALLOY MATERIAL COATED WITH COPPER AND METHOD FOR MANUFACTURING THE SAME}

The present invention relates to a copper-coated iron-copper alloy material and a method for manufacturing the same, wherein an iron-copper (Fe-Cu) alloy is used as a main body according to one embodiment, and the iron-copper (Fe- Copper (Cu) is self-coated on the surface of the Cu) alloy, and the present invention relates to a copper-coated iron-copper alloy material having high mechanical properties and economical efficiency, and the like and a method of manufacturing the same.

In general, copper (Cu, copper) is widely used in products that require electrical conductivity. Examples include connectors, terminals, ground wires, electrodes, relays, springs, switches, and lead frames used in electrical and electronic devices, communication devices, electrical parts, electronic parts, automobile parts, and semiconductor parts. Moreover, although copper has high electrical conductivity, since it is weak in strength etc., the copper alloy material which alloyed another metal to copper is mainly used.

In recent years, as various electric and electronic devices, communication devices, and the like become smaller, lighter, and higher in performance, there is a demand for improvement of properties even in the case of the copper alloy materials used therein. For example, high electrical conductivity as well as high strength, weldability and economy are required.

A high strength copper alloy material is a beryllium-copper (Be-Cu) alloy. For example, Japanese Unexamined Patent Publication No. JP2003-003246, Korean Unexamined Patent Publication No. 10-2012-0048287, Korean Unexamined Patent Publication No. 10-2015-0053814, and the like disclose a technique related to a beryllium-copper (Be-Cu) alloy. Is presented.

However, the beryllium-copper (Be-Cu) alloy has a high strength, but the electrical conductivity is low, constituting beryllium (Be) is harmful to the human body. In addition, the beryllium-copper (Be-Cu) alloy is difficult to continuously cast, beryllium (Be) is a low raw material because of the high raw material price. Accordingly, beryllium-copper (Be-Cu) alloy is limited in some products, there is a problem inferior in versatility.

In addition, copper alloy materials containing copper (Zn), tin (Sn), nickel (Ni) and the like as main components have been proposed. For example, Japanese Unexamined Patent Publication No. JP2007-056365, Korean Unexamined Patent Publication No. 10-2014-0127911, and Korean Unexamined Patent Publication No. 10-2015-0109378 are used as constituent materials of connectors and terminals of electrical and electronic devices. Copper alloy materials, such as a Cu-Zn-Sn alloy and a Cu-Zn-Sn-Ni alloy, are proposed as a copper alloy material used. However, even in the case of such a copper alloy material, the electrical conductivity is low and the price of zinc (Zn), tin (Sn), nickel (Ni), etc. is high, so economic efficiency is low, which is also insufficient mechanical properties such as strength.

Japanese Laid-Open Patent Publication JP2003-003246 Korean Unexamined Patent Publication No. 10-2012-0048287 Korean Unexamined Patent Publication No. 10-2015-0053814 Japanese Laid-Open Patent Publication JP2007-056365 Korean Unexamined Patent Publication No. 10-2014-0127911 Korean Unexamined Patent Publication No. 10-2015-0109378

Accordingly, the present invention is an iron alloy material containing copper that can be used very usefully at least in products requiring electrical conductivity, and has a high electrical conductivity and improved mechanical properties and economics, such as iron-copper alloy material and a method of manufacturing the same And it is an object to provide a product comprising the iron-copper alloy material.

The present invention to achieve the above object,

Iron-copper (Fe—Cu) alloys; And

It provides a copper-coated iron-copper alloy material comprising a copper layer formed on the surface of the iron-copper (Fe-Cu) alloy.

According to one embodiment, the copper layer is formed by heat-treating the iron-copper (Fe-Cu) alloy and eluting copper contained in the iron-copper (Fe-Cu) alloy to the surface.

In addition, the present invention,

A first step of obtaining an iron-copper (Fe—Cu) alloy; And

It provides a method of manufacturing a copper-coated iron-copper alloy material comprising a second step of forming a copper layer on the surface of the iron-copper (Fe-Cu) alloy.

According to one embodiment, the second step is heat-treating the iron-copper (Fe-Cu) alloy obtained in the first step, the copper contained in the iron-copper (Fe-Cu) alloy elutes to the surface To form a copper layer. In addition, the iron-copper (Fe-Cu) alloy may include 55 to 95 atomic% iron (Fe) and 5 to 45 atomic% copper (Cu).

In addition, the present invention provides a product comprising the copper coated iron-copper alloy material. The product may for example be selected from connectors, terminals, ground wires or electrodes and the like.

According to the present invention, an iron-copper (Fe-Cu) alloy is used as a main body, and copper (Cu) is coated on the surface to have high electrical conductivity while improving mechanical properties and economic efficiency. Accordingly, it can be usefully applied to products requiring at least electrical conductivity.

In addition, according to the present invention, according to one embodiment, the copper (Cu) is coated by itself through a high temperature heat treatment, the manufacturing process of the copper coating is simple, and has the effect of implementing the copper coating with high purity.

1 is a cross-sectional configuration diagram of an iron-copper alloy material according to an embodiment of the present invention.
2 is a configuration diagram for explaining a manufacturing process of the iron-copper alloy material according to the embodiment of the present invention.
3 is a BH curve of the Fe-Cu alloy prepared according to the embodiment of the present invention.
Figure 4 is a SEM photograph of the magnification of the Fe-Cu alloy particles prepared according to the embodiment of the present invention.
5 is an EDS analysis result of the Fe—Cu alloy particles prepared according to the embodiment of the present invention.
6 is an EDS analysis result of the Fe—Cu alloy particles prepared according to the embodiment of the present invention.
7 is an EDS analysis result of the Fe—Cu alloy particles prepared according to the embodiment of the present invention.
8 is an SEM photograph of a particle specimen according to a comparative example.
9 is a surface image before and after the heat treatment of the iron-copper alloy material according to an embodiment of the present invention.

As used herein, the term "and / or" is used in a sense including at least one or more of the components listed before and after. As used herein, the term "one or more" means one or more than one. In addition, the terms "first" and "second" as used herein are used to distinguish one component from another component, and each component is not limited by the terms.

The present invention provides a copper coated iron-copper alloy material according to the first aspect. The present invention provides a method for producing the copper-coated iron-copper alloy material according to the second aspect. The present invention also provides a product comprising the copper-coated iron-copper alloy material according to the third aspect.

1 and 2 show a copper coated iron-copper alloy material according to an embodiment of the present invention. The accompanying drawings show exemplary embodiments of the invention, which are provided merely to assist in understanding the invention. In the accompanying drawings, in order to clearly express each component and region, the thickness may be enlarged, and the scope of the present invention is not limited by the thickness, size, and ratio shown in the drawings. Hereinafter, in describing the present invention, detailed descriptions of related well-known general functions and / or configurations will be omitted.

1, a copper coated iron-copper alloy material (hereinafter abbreviated as "alloy material") according to an embodiment of the present invention, which illustrates an alloy material 10 having a rectangular cross section. The alloy material 10 according to the present invention includes an iron-copper alloy (Fe-Cu Alloy) and a copper (Cu) layer formed on the surface of the iron-copper alloy (Fe-Cu Alloy).

Specifically, the alloy material 10 according to the present invention includes a main body 12 and a coating layer 14 formed on the surface of the main body 12, wherein the main body 12 is an iron-copper alloy 12 , The coating layer 14 is composed of a copper layer (14). The copper layer 14 may be coated with, for example, molten copper (Cu) by spraying or depositing (impregnating) the surface of the iron-copper alloy 12.

The iron-copper alloy 12 as the body 12 is an alloy of iron (Fe) and copper (Cu), which is an iron-copper alloy 12 having a specific composition according to one embodiment. The specific configuration of this iron-copper alloy 12 will be described later. In addition, although the copper layer 14 as the coating layer 14 may contain an unavoidable impurity, it is copper (Cu) having a purity of 99.9 wt% or more.

According to one embodiment, the copper layer 14 is formed through self-coating by high temperature heat treatment of the iron-copper alloy 12. Specifically, the copper layer 14 is formed by heat-treating the iron-copper alloy 12, and copper (Cu) contained in the iron-copper alloy 12 is eluted to the surface.

In the present invention, the shape and size of the alloy material 10 and the main body 12 are not limited. The alloy material 10 according to the present invention may have, for example, a plate shape, a linear shape, a spherical shape, or a three-dimensional shape other than these. The alloy material 10 according to the present invention may have an external shape selected from, for example, a square plate shape, a disc shape, a hexahedron, a cylinder shape, and the like. In addition, the alloy material 10 according to the present invention may have a shape of a product selected from, for example, a connector, a terminal, a ground wire, an electrode, a relay, a spring, a switch, a lead frame, or the like and may constitute a product. It may have a shape of.

On the other hand, the manufacturing method of the alloying material 10 according to the present invention is the first step of obtaining the iron-copper alloy 12, and the second to form a copper layer 14 on the surface of the iron-copper alloy 12 Steps. According to one embodiment, in the second step, the iron-copper alloy 12 obtained in the first step is heat-treated to allow copper (Cu) contained in the iron-copper alloy 12 to elute to the surface. Form layer 14. Hereinafter, specific embodiments of the alloying material 10 according to the present invention will be described with reference to each step embodiment.

[1] iron-copper alloys

The iron-copper alloy 12 has a specific alloy composition. According to the present invention, when the iron-copper alloy 12 has a specific alloy composition, it is possible to self-coated copper (Cu) by heat treatment while having excellent mechanical properties (strength, etc.). It also has high electrical conductivity and economy.

Hereinafter, the iron-copper alloy specified in the present invention will be described. The present inventors have been presented in Korean Patent Application No. 10-2017-0015982 (Registration No. 10-1910015) for the iron-copper alloy.

The iron-copper alloy constituting the main body 10 includes iron (Fe) and copper (Cu), but an iron-based copper alloy having a higher content of iron (Fe) than copper (Cu), which is iron (Fe) and The total standard of copper (Cu) includes 55 to 95 atomic percent iron (Fe) and 5 to 45 atomic percent copper (Cu).

The content unit "atomic%" used in the present invention is based on the entire atomic (a sum of Fe and Cu) of iron (Fe) and copper (Cu), which is also known in the metal field as Volume% ”. That is, in the present invention, it may be expressed as atomic% = volume%.

According to one embodiment, the iron-copper alloy does not contain metal elements other than iron and copper. In addition, the iron-copper alloy may include impurities such as carbon (C) and oxygen (O) as unavoidable impurities, but such impurities are very small. Impurities may be inevitably included, for example, at most 0.1 atomic% (0.1 vol%), or at most 0.01 atomic%.

The iron-copper alloy includes an appropriate amount of copper in iron, so that the advantages of iron and copper are well coordinated and have improved properties. The iron-copper alloy has a predetermined electrical conductivity while having excellent mechanical properties, thermal conductivity, heat resistance and economical efficiency. In addition, the iron-copper alloy can be copper coating itself by heat treatment.

Specifically, the iron-copper alloy specified in the present invention has superior strength, hardness, wear resistance, thermal conductivity, heat resistance, and the like, compared to pure copper (Cu) or a conventional copper alloy material. In addition, the iron-copper alloy can be welded, and has a high economic efficiency using a low-cost iron (Fe) as a base (main component). In addition, it is possible to have a self-coating by the heat treatment to have a high electrical conductivity. In the present invention, " self copper coating " means that copper (Cu) contained in the iron-copper alloy itself elutes to the surface to form the copper layer 14.

The iron-copper alloy may be prepared as follows. The manufacturing method described below easily implements the production of the iron-copper alloy having the specific composition. However, the iron-copper alloy is not limited to that produced by the manufacturing method described below.

The manufacturing method of the iron-copper alloy (hereinafter, abbreviated as "alloy manufacturing method") is a first step of preparing a melting furnace, a second step of adding iron and copper to the melting furnace to melt to form a molten metal, the And a third step of stabilizing the molten metal, and a fourth step of injecting and casting the stabilized molten metal into a casting mold. In addition, the alloy manufacturing method may further include a fifth step of obtaining powdered iron-copper alloy particles from the casting obtained through the fourth step as an optional step.

(1) Melting Furnace Preparation (Step 1)

As described above, the iron-copper alloy specified in the present invention contains 55 to 95 atomic% iron and 5 to 45 atomic% copper. The alloy composition specified in the present invention is not a theoretical molten alloy composition. That is, the proportion of iron in excess of the amount that can theoretically be alloyed. This alloy composition is difficult to be made into an amorphous complete alloy through a melting method by melting (molten metal). In general, the molten alloy may be made of iron and copper when the iron content is lower than that of copper (eg, less than 2.5% by volume of Fe content). However, in the case of the alloy composition specified in the present invention, two-phase separation of the Fe-rich phase and the Cu-rich phase occurs in the molten metal, and segregation (which one metal is biased in one place) occurs, resulting in a complete molten alloy having a uniform distribution. It is difficult to make.

As a result of numerous studies to achieve a complete molten alloy with a high iron content, the present inventors have found that without proper segregation (biasing) when the copper content is titrated, the impurities are minimized, and / or the dissolution process is improved. It can be seen that a complete molten alloy is achieved. That is, according to the present inventors, it can be seen that a complete molten alloy is achieved in the case of improving the melting furnace and / or improving the raw material input method in the melting process.

In this first step, one embodiment for solving the above problems is provided. According to the first step, a melting furnace for forming a molten iron and copper molten metal is prepared, but the melting furnace uses a melting furnace of high frequency induction heat capable of rapid melting through rapid temperature rise. In addition, it is preferable to use a ceramic melting furnace containing magnesium as a main component. As the ceramic melting furnace, for example, one manufactured by heating a ceramic containing magnesium oxide as a main component at high temperature and firing can be used. Such furnaces readily implement alloys of iron-copper.

According to one embodiment, the melting furnace is used by forming a porous impurity absorbing layer on the inner surface. Specifically, the first process includes preparing a ceramic melting furnace of high frequency induction heat, and forming a porous impurity absorbing layer on the inner surface of the ceramic melting furnace. In this case, the impurity absorbing layer may be formed on the whole or part of the inner surface of the melting furnace, and specifically, may be formed on at least an inner bottom surface and / or a wall inner surface of the melting furnace as a surface in contact with the molten metal.

In addition, the impurity absorbing layer contains at least an impurity absorbent. Specifically, in the surface treatment step, an absorbing layer composition including an impurity absorbent, a resin, and a solvent may be applied to the inner surface of the melting furnace, and then calcined to form a porous impurity absorbing layer. According to the present invention, the porous impurity absorbing layer absorbs and removes impurities (for example, C, O, etc.) contained in the molten iron-copper molten metal and segregates even in the non-theoretical alloy composition. Without complete alloying is achieved. The porous impurity absorbing layer may have a thickness of, for example, 0.5 mm to 2 mm, but is not limited thereto.

The impurity absorbent is not particularly limited as long as it can absorb and remove impurities (for example, C, O, etc.) contained in the molten iron-copper. The impurity absorbent may be in the form of a powder, for example, having a size of 50 to 500 μm. The impurity absorbent may be selected from a metal oxide and / or a metal, which may include at least one selected from zirconium silicate and aluminum (Al). Preferably, the impurity absorbent uses both zirconium silicate and aluminum (Al). At this time, the aluminum (Al) may be used having a high purity of 99.8% by weight or more. The above zirconium silicate and aluminum (Al) as the impurity absorber can remove impurities in the molten metal more effectively than other metal oxides or metals, and are preferable in the present invention. Specifically, the zirconium silicate and aluminum (Al) may completely remove impurities in the molten metal to form a high purity alloy molten metal including only iron and copper. This can also be confirmed by the following examples.

In addition, the resin is not particularly limited as long as it has an adhesive property, and this resin may be any material capable of providing initial adhesion between the inner surface of the melting furnace and the impurity absorbing layer while aggregating the powdery impurity absorbents with each other. In addition, the resin is removed by high temperature heat by sintering to impart porosity to the impurity absorbing layer. The resin may be selected from synthetic resins and / or natural resins. The resin may be solid and / or liquid, which may be, for example, one or more polymers and / or copolymers thereof selected from acrylic, vinyl, epoxy, urethane, silicone, olefin, ester, rubber and the like. Can be selected.

For example, the butadiene-styrene-alkyl methacrylate copolymer may be used as the resin. The butadiene-styrene-alkyl methacrylate copolymer is, for example, butadiene-styrene-methyl methacrylate copolymer, butadiene-styrene-ethyl methacrylate copolymer and / or butadiene-styrene-butyl methacrylate air Coalescing and the like. In one example, the butadiene-styrene-alkyl methacrylate copolymer may be used having a particle size of 50nm to 500nm. As such, when the butadiene-styrene-alkyl methacrylate copolymer is selected as the resin and one having a nano size is used, it can be quickly removed through calcination and is evenly dispersed between the powdery impurity absorbents. As a result, the cohesion between the impurity absorbents is improved, and a homogeneous and fine porous structure is formed in the impurity absorber layer, thereby improving the absorption and removal capability of the impurity.

The solvent is for dispersibility and applicability, which may be selected from hydrocarbon systems. The solvent may be selected from, for example, alcohols and / or ketones.

In addition, the absorbent layer composition may include 50 to 80% by weight of impurity absorbent, 5 to 20% by weight of resin, and 15 to 40% by weight of solvent in one example. In this case, when the content of the impurity absorbent is less than 50% by weight, the absorption and removal ability of the impurity may be insignificant, and when the content of the impurity absorber exceeds 80% by weight, porosity and applicability may be deteriorated. In addition, when the content of the resin is less than 5% by weight, porosity and adhesion may be lowered, and when the content of more than 20% by weight, the content of the impurity absorbent is relatively low, so that the absorption and removal capability of the impurities may be insignificant. And a solvent is good in the said range in consideration of dispersibility and applicability | paintability.

As described above, when the porous impurity absorbing layer is formed on the inner surface of the melting furnace through the first process, impurities contained in the molten metal are absorbed and removed during the dissolution process to form a homogeneous complete iron-copper alloy, and together with the impurities It is possible to effectively obtain a high-purity iron-copper alloy containing almost no.

(2) Dissolution (2nd step)

An alloy raw material of iron and copper is introduced into the melting furnace. In this case, iron may use high purity pure iron, and the copper may use high purity electrolytic copper. The furnace may be heated by high frequency induction heat by power application. The melting furnace may be maintained at a temperature at which iron and copper can be dissolved. For example, it is preferable to dissolve iron and copper by rapidly heating the melting furnace through high frequency induction heat and maintaining the temperature at about 1,520 ° C to 1,650 ° C. In this dissolution process, stirring may proceed.

In the second process, the iron and the iron in the melting furnace to include 55 to 95 atomic% (or volume%) and 5 to 45 atomic% (or volume%) of iron as the total basis of the iron-copper alloy finally produced. Copper is added and dissolved to form a molten metal. Specifically, the alloy composition is obtained when the total input of iron and copper to the furnace is 55 to 95% by volume of iron and 5 to 45% by volume of copper (that is, volume ratio of iron: copper = 55 to 95: 5 to 45). can do. In this case, when the content of copper is less than 5 atomic% (5 volume%), for example, electrical conductivity, thermal conductivity and / or corrosion resistance may be insignificant. And when the content of copper exceeds 45 atomic% (45% by volume), the iron content is relatively low, for example, mechanical / thermal properties such as strength, hardness, wear resistance and heat resistance can be lowered.

According to the embodiment of the present invention, in consideration of the above, in the second process, the iron-copper alloy includes 80 to 95 atomic% of iron and 5 to 20 atomic% of copper, based on the total basis of the finally produced iron-copper alloy. Iron and copper are added and dissolved to form a molten metal. That is, when the total amount of iron and copper input to the furnace is 80 to 95% by volume of iron and 5 to 20% by volume of copper (ie, iron: copper = 80 to 95: 5 to 20 by volume), the alloy composition It is good. More specifically, for example, iron and copper may be added to and dissolved in the melting furnace so as to include 80.5 to 95 atomic% iron and 5 to 19.5 atomic% copper. In the case of having such an alloy composition, it has excellent electrical conductivity, thermal conductivity, heat resistance, mechanical properties, and the like, and is very useful as a material of the main body 12.

According to one embodiment, in introducing iron and copper into the melting furnace, iron and copper are initially added in a volume ratio of 1: 1, rapidly dissolved while stirring, and then iron is further added to the alloy. It can be made to have a composition. In other words, rather than having the alloy composition through a single input, it is initially added in a volume ratio of 1: 1 iron and copper, and then an additional iron is added to the alloy composition of the homogeneous iron-copper. desirable. In addition, it is more preferable to intermittently add little by little at the time of addition of iron. In other words, the addition of iron in small quantities over several times is advantageous for the homogeneous alloy composition.

In addition, in this 2nd process (dissolution process), it can advance, adding a deoxidizer to a melting furnace and deoxidizing (oxidation prevention). In addition, flux can be further added in this 2nd process (melting process). At this time, the deoxidizer and flux may be used that is commonly used in the field of alloys. The deoxidizer may be, for example, 99.8% by weight or more of high purity Al and / or high purity Ti, and the flux may be Al ₂ O ₃ , CaO and / or SiO ₂ , or the like.

(3) Stabilization (3rd step)

The melt formed through the dissolution is stabilized. Stabilization may be performed by interrupting the power supply to the furnace and leaving the molten metal in the furnace for a predetermined time. At this time, the stabilization may proceed by maintaining the molten metal temperature, for example, 1,450 ℃ to 1,520 ℃. By this stabilization, homogenization of iron and copper can be achieved.

(4) Casting (4th process)

The stabilized molten metal is injected into a casting mold and cast into an alloy casting of a certain form. This 4th process (casting) is based on a normal metal casting process. The casting mold is not particularly limited, and may have a shape of an ingot and a casting piece, or in some cases, a product shape such as a connector or a terminal. In addition, the casting mold may have a cooling function as usual.

In addition, the casting obtained through the fourth process may be post-processed through a process such as conventional heat treatment and / or cooling. The casting may be post-processed through, for example, a process such as annealing, normalizing, quenching and / or tempering. Such post-treatment can improve mechanical properties (tensile strength, flexural strength, compressive strength and hardness, etc.). The casting thus obtained can be used for the manufacture of the body 12.

(5) Granulation (5th step)

This fifth process is an optional process, through which a powdered iron-copper alloy can be obtained. According to this fifth step, the casting obtained in the fourth step (casting) is redissolved and then sprayed to obtain powdered iron-copper alloy particles. Specifically, the fifth process may include a re-dissolving step of re-dissolving the casting, and a granulation step of spraying the re-dissolved melt to obtain powdered iron-copper alloy particles.

In this case, the remelting step may use the same melting furnace as in the first step. In the re-dissolving step of the fifth process, in order to prevent oxidation of the iron-copper alloy, it is preferable to re-dissolve in a melting furnace of a vacuum. That is, a melting furnace can use a vacuum furnace. In such a vacuum furnace, the casting may be re-dissolved at 1,600 ° C to 1,700 ° C. In the granulation step, the re-dissolved melt may be sprayed at 1,400 ° C. to 1,500 ° C. to granulate the powder. In this case, the granulated powder may have a size of, for example, 0.1 μm to 150 μm. The powdered iron-copper alloy particles thus obtained may have a spherical particulate form.

According to the above manufacturing method, iron-copper alloy containing 55 to 95 atomic% iron and 5 to 45 atomic% copper, which is a non-theoretical alloy composition, but complete alloying without segregation (biasing). In addition, the iron-copper alloy is well coordinated with the advantages of iron and copper, as described above the body having excellent electrical conductivity, thermal conductivity, heat resistance and mechanical properties (tensile strength, bending strength, compressive strength and hardness, etc.) Very useful as a material of (12).

Further, as mentioned above, according to one embodiment, the iron-copper alloy comprises 80 to 95 atomic percent iron and 5 to 20 atomic percent copper. Specifically, it may include 80.5 to 95 atomic% iron and 5 to 19.5 atomic% copper, and more specifically, 82.5 to 90.5 atomic% iron and 9.5 to 17.5 atomic% copper. In the case of such an alloy composition, properties such as electrical conductivity, thermal conductivity, heat resistance, and mechanical properties are effectively improved.

According to one embodiment, the iron-copper alloy has the same composition as above, but preferably has a thermal conductivity of 70 W / m · K or more. According to a specific embodiment, it is preferable that the iron-copper alloy has physical properties of the following (a) to (c). When having the physical property of following (a)-(c), it is very useful as a structural material, such as an electrical and electronic device, and also is preferable also in durability.

(a) Thermal conductivity 70 W / mK or more

(b) tensile strength over 300 N / mm2

(c) hardness of 100 HB or more

The thermal conductivity, tensile strength and hardness are in accordance with conventional measuring methods. The thermal conductivity may be, for example, a value measured at room temperature (20 ° C. to 25 ° C.) according to ASTM E1461 (Laser flash: Thru-plane). And tensile strength is measured according to KS B 0801, hardness may be measured according to KS B 0805.

The thermal conductivity may specifically have 70 to 150 W / m · K, for example, preferably 72 W / m · K or more, and more preferably 75 W / m · K or more. In addition, the tensile strength may have, for example, 300 to 1,350 N / mm 2. And the hardness is Brinell Hardness (Brinell Hardness), which may have a specific H 100 ~ 400 HB, for example. Each of these properties can be optimized according to the application. For example, in the case of the tensile strength and hardness, it can be increased through the post-treatment (such as soaking, quenching and tempering, etc.) as described above, by such a post-treatment tensile strength is 500 N / ㎜ or more, hardness is 200 HB It can have more than.

In addition, the iron-copper alloy may have a spherical particulate form. The spherical particulate phase may be implemented through the fifth process. At this time, the iron-copper alloy has a spherical particulate form, for example, may have a size (diameter) of 0.1㎛ ~ 150㎛. Here, "spherical" does not mean only a perfect sphere, which includes a quasi-spherical as well as a complete spherical.

In addition, in the present invention, the "spherical particles", even though the iron-copper alloy is a non-theoretical alloy composition, iron and copper are uniformly distributed in the alloy and a complete molten alloy is formed without segregation (declination). Means. In this sense, "spherical particles" have a technical significance. In other words, when a complete molten alloy is not achieved, it is difficult to have spherical particulates through spraying. In addition, in the present invention, the "spherical particles" has a technical significance in that the iron-copper alloy molding having a uniform composition can be processed through re-dissolution.

The iron-copper alloy described above is used as the material of the alloying material 10 according to the present invention, that is, the body 12. At this time, the main body 12 uses an iron-copper alloy casting (an ingot or a cast piece) obtained in the fourth step (casting), or uses powdered iron-copper alloy particles obtained in the fifth step (granulation). Can be molded. According to one embodiment, the main body 12 is manufactured to melt an iron-copper alloy casting (an ingot or cast piece) or an iron-copper alloy particle, and then have a predetermined shape by, for example, injection molding or the like. Can be. As described above, the shape of the main body 12 is not particularly limited, and may have, for example, a product shape such as a connector or a terminal.

[2] copper coatings

As described above, the copper layer 14 as the coating layer 14 may be composed of copper (Cu) having a purity of 99.9 wt% or more. According to one embodiment, the copper layer 14 is formed by self-coating by heat treatment of the body 12, that is, heat treatment of the iron-copper alloy 12. To this end, the iron-copper alloy 12 is subjected to high temperature heat treatment. At this time, copper (Cu) contained (diffused) in the iron-copper alloy 12 itself is eluted to the surface to form a copper layer 14 having a purity of 99.9 wt% or more. This is as shown in FIG.

Referring to FIG. 2, when heat is applied to the iron-copper alloy 12, copper (Cu) constituting the iron-copper alloy 12 is melted (liquefied). The molten (liquefied) copper (Cu) is deposited and coated on the surface of the iron-copper alloy 12 by volume expansion. By this heat treatment, a high purity copper layer 14 having a predetermined thickness is formed.

The heat treatment may be applied to the iron-copper alloy (12). The heat treatment may be performed in a heating furnace such as an electric furnace. The heat treatment may be performed in a non-oxidizing atmosphere, for example, a vacuum atmosphere or an inert gas (Ar, N _2, etc.) atmosphere.

The heat treatment is carried out at an appropriate temperature in consideration of the melting points of copper (Cu) and iron-copper alloy (12). That is, the heat treatment proceeds at a temperature higher than the melting (about 1,085 ° C) of copper (Cu). In addition, the iron-copper alloy 12 is lower than the melting point of iron (Fe) (about 1,538 ° C), and may have a melting point of about 1,493 ° C or less. Thus, the heat treatment is a temperature lower than the melting point of the iron-copper alloy 12, it is preferable to proceed at a temperature of about 1,493 ℃ or less. Specifically, the heat treatment may be performed in a temperature section of about 1,100 ℃ ~ 1,490 ℃, or about 1,100 ℃ ~ 1,450 ℃.

According to one embodiment, the heat treatment may be carried out by charging the iron-copper alloy 12 into a heating furnace such as an electric furnace and then maintaining a temperature of, for example, 1,100 ° C to 1,450 ° C. At this time, when the heat treatment temperature is less than 1,100 ℃ it may be difficult to elute the surface of the copper (Cu). And when the heat treatment temperature is too high, exceeding 1,450 ℃, the copper-copper alloy 12 itself may be melted. According to a more specific embodiment, the heat treatment may proceed at a temperature of 1,200 ° C. to 1,450 ° C. so that copper (Cu) can be rapidly eluted to the surface while preventing melting of the copper-copper alloy 12.

The copper layer 14 may have a thickness of, for example, 5 nm to 20 μm. At this time, if the copper layer 14 is too thin, the electrical conductivity of the alloy material 10 may be insignificant, and if the copper layer 14 is too thick, the surface strength of the alloy material 10 may be weakened. In consideration of this point, the copper layer 14 may have a thickness of 0.1 μm to 1 μm. In addition, the thickness of the copper layer 14 may be adjusted through the heat treatment time. That is, the longer the heat treatment time is, the thickness of the copper layer 14 increases. In consideration of this, the heat treatment time may be adjusted to have an appropriate thickness. The heat treatment may be performed, for example, for 10 seconds to 1 hour, but is not limited thereto.

After the heat treatment as described above can be cooled. Cooling may, for example, proceed slowly at room temperature. When cooling is complete | finished, the alloy material 10 which self-coated the copper layer 14 on the surface of the iron-copper alloy 12 as a main body 12 is produced.

Therefore, according to the copper coating as described above, in forming the copper layer 14 on the surface of the iron-copper alloy 12, self-coating (elution) by heat treatment without melting and coating a separate copper (C) Through the high purity copper layer 14 can be simply coated.

After proceeding with the copper coating as described above may be processed as an optional process. The said processing process is surface treatment processes, such as surface grinding | polishing, etc. are mentioned, for example. In addition, the processing step may include a product forming step such as cutting and / or bending to form a product such as a connector or a terminal.

According to the present invention described above, while having at least high electrical conductivity, mechanical properties, economical efficiency and the like are improved. That is, the alloy material 10 according to the present invention has at least high electrical conductivity by the high purity copper layer 14. The alloy material 10 according to the present invention may have a specific resistance of 2.4 μΩ · cm or less, for example. The alloy material 10 according to the present invention may have a specific resistance of, for example, 1.73 μΩ · cm to 2.4 μΩ · cm. Accordingly, it can be very usefully applied to products requiring at least electrical conductivity.

In addition, as described above, the iron-copper alloy 12 as the main body 12 has excellent mechanical properties, and since it is composed of iron (Fe), which is inexpensive, as a base (main component), high economical efficiency and the like. Has

The alloy material 10 according to the present invention can be used as a constituent material of, for example, an electric / electronic device, a communication device, an electric part, an electronic part, an automotive part, a semiconductor part, and the like, for which electrical conductivity is required. In addition, the product according to the present invention is not particularly limited as long as it includes the alloy material 10, which may be selected from, for example, a connector, a terminal, a ground wire, an electrode, a relay, a spring, a switch, and a lead frame.

Hereinafter, the Example and comparative example of this invention are illustrated. The following examples are provided by way of example only to help understanding of the present invention, whereby the technical scope of the present invention is not limited. In addition, the following comparative examples do not imply prior art, they are provided only for comparison with the examples.

1. Alloy Manufacturing

Example 1

<Melting Furnace>

As a high frequency induction heat melting furnace, a ceramic melting furnace mainly composed of magnesium was prepared. Thereafter, a porous impurity absorbing layer was formed on the inner wall and bottom of the prepared melting furnace. The porous impurity absorbing layer is coated with an absorbent layer composition containing 65% by weight of impurity absorbent, 15% by weight of resin, and 30% by weight of solvent, based on the total weight of the composition, and then heated to a temperature of about 1,150 ° C., It calcined and formed. In this case, zirconium silicate (ZrSiO ₄ ) and Al powder were used as the impurity absorbent, butadiene-styrene-methyl methacrylate copolymer was used as the resin, and isopropyl alcohol was used as the solvent.

<Molten / Stabilized / Foundry>

Iron (purity of about 99.9 wt% pure iron) and copper (electrolytic copper of about 99.9 wt% purity) were initially added to the melting furnace at a volume ratio of 1: 1, and the output was rapidly dissolved while stirring while increasing the output. At this time, in the dissolution process, deoxidizing agent (Al) was added intermittently while deoxidizing. In addition, after confirming the complete dissolution of the added iron and copper through visual observation, in order to increase the iron content of iron was added little by little and completely dissolved at about 1,550 ℃ melt temperature. Thereafter, the power of the melting furnace was cut off and allowed to stand until the molten metal temperature became about 1,500 ° C. Next, the stabilized molten metal was poured into a casting mold, and then cooled to obtain a Fe—Cu alloy ingot.

EXAMPLE 2 AND 3

Compared to Example 1, in order to change the final alloy composition (atomic% of Fe and Cu), the same as in Example 1 except that the addition amount of iron in the melting process was changed to Fe-Cu alloy ingots were obtained.

Comparative Example 1

In forming the porous impurity absorbing layer on the inner surface of the melting furnace, it was carried out in the same manner as in Example 1 except that the type of impurity absorbent was changed. Specifically, it was carried out in the same manner as in Example 1 except that zirconium oxide (ZrO ₂ ) was used instead of zirconium silicate (ZrSiO ₄ ) and Al as the impurity absorber.

Comparative Example 2

Compared to Example 1, the iron and copper in the melting furnace at a 9: 1 by volume ratio, and the inner surface of the furnace was prepared by melting without forming a porous impurity absorbing layer in this Comparative Example 2 Was used as a specimen.

For the Fe-Cu alloy specimens obtained as above, the components were analyzed as follows, and the results are shown in the following [Table 1]. In addition, the thermal conductivity, tensile strength, hardness and permeability of each alloy specimen were evaluated, and the results are shown together in the following [Table 1]. Thermal conductivity is a method of measuring the thermal conductivity of a metal sample, and the density, specific heat, and thermal diffusivity of each alloy specimen were measured, and then evaluated according to ASTM E1461 (Laser flash: Thru-plane). At this time, all the tests were carried out at a temperature of 25 ℃. In addition, tensile strength was evaluated according to KS B 0801, and hardness was evaluated by Brinell Hardness according to KS B 0805. The permeability was evaluated at a frequency of 50 Hz using a permeability measuring instrument (product of Japan, Lee Yeon Electronics Co., Ltd., model name BHU-60).

<Component Analysis>

The weighed alloy specimen was placed in a glass beaker and 10 mL of aqua regia (hydrochloric acid + aqueous sulfuric acid solution) was added to dissolve it. In addition, Fe and Cu were quantified by high frequency inductively coupled plasma emission spectrometry (ICP-AES) according to the following measurement conditions, and converted into concentrations in the sample for analysis.

* Measurement condition of ICP-AES

Measuring device: PerkinElmer Optima 5300DV

Measurement wavelength: 238.204nm (Fe), 327.393nm (Cu)

-Quantitative method: Internal standard method

                <Component Analysis and Property Evaluation Results of Fe-Cu Alloy>
Remarks
impurities
Absorbent Ingredient composition
(atom%)
Thermal conductivity
[W / mK]
The tensile strength
[N / mm2]
Brinell hardness
[HB]
Permeability
[m _m ] Fe
Cu Example 1
ZrSiO ₄ + Al 89.58 10.42 74.3 327 154 630 Example 2
ZrSiO ₄ + Al 88.32 11.68 76.6 323 143 613 Example 3
ZrSiO ₄ + Al 90.07 9.93 70.5 342 161 637 Comparative Example 1
ZrO ₂ Segregation 56.1 crack - - Comparative Example 2
- Segregation 47.3 crack - -

As shown in Table 1, in the case of the Fe-Cu alloy according to the embodiments, it can be seen that it has a high thermal conductivity of 70 W / m · K or more than the comparative examples. In addition, it can be seen that the Fe-Cu alloys according to the embodiments have a tensile strength of 320 N / mm 2 or more and a hardness of 140 HB or more. In this case, a high tensile strength of 320 N / mm 2 or more means that a complete alloy was formed while the Fe and Cu had a uniform distribution without segregation (declination). In addition, approximately 600 m _m It can be seen that the level of permeability is shown, which means that it has electromagnetic shielding ability. The attached Figure 3 shows the BH curve (magnetization curve) of the alloy according to Example 1, which means that it has a soft magnetic properties.

On the contrary, in the comparative examples, it was found that segregation occurred without a complete alloy. In addition, the crack was generated due to segregation during the measurement of the tensile strength, it was impossible to measure the tensile strength. In addition, in the case of the comparative examples, because the components are non-uniform due to segregation, it can not be accurately evaluated, it is not shown in Table 1. Hardness and permeability are not shown for the same reason.

Table 2 shows the results of evaluation of physical properties according to the post-treatment, which shows the results before and after treatment for the same alloy specimen as in Example 2. Post-treatment was performed by annealing, normalizing, quenching and tempering in a conventional manner.

        <Result of Property Change by Post-treatment of Fe-Cu Alloy>
Remarks
Before treatment
(Example 2) After Treatment (Example 2) Annealed calling out Quenching (900 ℃)
+ Tempering Quenching (1,050 ℃)
+ Tempering The tensile strength
[N / mm2] 323 301 604 1,016 1,311 Elongation
[%] 10 30 15 3 One Brinell hardness
[HB] 143 100 207 282 374

As shown in [Table 2], the Fe-Cu alloy was found to change the physical properties by the post-treatment. For example, when quenching (and tempering) at a temperature of 1,050 ° C., the tensile strength of 1,300 N / mm 2 or more and the hardness of 370 HB or more were found, and the mechanical strength was improved. As such, when the mechanical strength is improved by heat treatment like ordinary pure single metal (such as pure iron), this means that a complete alloy has been achieved.

[Examples 4 to 6]

Compared to Example 1, in order to change the final alloy composition (atomic% of Fe and Cu), except that the addition amount of iron in the dissolution process was carried out in the same manner as in Example 1 each Example Fe-Cu alloy ingot according to (4-6) was obtained. In addition, in the present embodiments, the Fe-Cu alloy ingot obtained through casting was granulated as follows to prepare powdery Fe-Cu alloy particles.

First, the Fe-Cu alloy ingots according to the respective examples (4 to 6) obtained through casting were put in a melting furnace of high frequency induction heat, and the maximum output was applied to redissolve at a temperature of about 1,650 ° C. At this time, the furnace was maintained in a vacuum to prevent oxidation. Next, the redissolved melt was sprayed using an injector to granulate. At this time, the injection chamber was maintained in an argon (Ar) gas atmosphere to prevent oxidation, and the melt was prepared by spraying at a temperature of 1,450 ℃.

4 to 7 show SEM photographs and EDS analysis results of the powdery Fe—Cu alloy particles prepared according to the examples (4 to 6). Figure 4 is a SEM picture of the magnification of the Fe-Cu alloy particles according to Example 4, Figure 5 shows the results of EDS analysis of the Fe-Cu alloy particles according to Example 4. And Figure 6 shows the results of EDS analysis of Fe-Cu alloy particles according to Example 5, Figure 7 shows the results of EDS analysis of Fe-Cu alloy particles according to Example 6.

As shown in Figures 4 to 7, it can be seen that the Fe-Cu alloy particles produced according to each of the embodiments (4 to 6) has a nearly full spherical shape as fine particles of 30㎛ or less. In addition, the three pictures shown at the bottom of Figure 5 shows the distribution of Fe and Cu (Fe: red, Cu: green), it can be seen that the Fe and Cu are uniformly distributed without segregation (biased) have. At this time, among the three pictures shown at the bottom of FIG. 5, the middle picture shows the distribution of Fe (red), the rightmost picture shows the distribution of Cu (green), and the leftmost picture shows the distribution of Fe and Cu. It is seen. As such, the Fe-Cu alloy particles having a perfect spherical shape and showing a uniform distribution mean that Fe and Cu are completely alloys.

On the other hand, Figure 8 attached is a SEM photograph of the particle specimen sprayed using an ingot according to Comparative Example 2. As shown in FIG. 8, in Comparative Example 2, the particles had a non-uniform piece shape due to segregation. This means that no complete alloy has been achieved.

2. copper coating

Example 7

A plate-like substrate was manufactured using the Fe-Cu alloy ingot according to Example 2, which showed good results among the examples of Fe-Cu alloy manufacturing. The substrate was placed in an electric furnace and then heat treated under a vacuum atmosphere. At this time, the temperature in the electric furnace was maintained at about 1250 ℃ and heat-treated for 3 minutes. 9 shows images before and after heat treatment (before copper coating) and after heat treatment (after copper coating). In FIG. 9, (a) is an image before heat treatment (before copper coating), and (b) is an image after heat treatment (after copper coating).

As shown in FIG. 9, it was found that Cu contained in the Fe-Cu alloy (diffusion) was eluted to the surface by heat treatment, and the surface of the substrate changed to yellow copper color.

In addition, Table 3 shows the results of measuring the specific resistance (μΩ · cm) and electrical conductivity (%) before heat treatment (before copper coating) and after heat treatment (after copper coating). At this time, the specific resistance was measured using a resistance meter (Mesisubishi, Japan, model name MCP-T610). The electrical conductivity (%) is expressed as a percentage of the specific resistance of the pure copper (Cu) before the heat treatment (before copper coating) and after the heat treatment (after copper coating) with respect to the specific resistance (1.7241 μΩ · cm) of pure copper (Cu).

[Equation]

Electric conductivity (%) = (Resistivity of pure Cu / Resistivity of Fe-Cu substrate) x 100

                 <Electrical characteristic measurement result> Remarks Resistivity
[μΩ · cm] Electrical conductivity
(Compared to pure Cu of 1.7241 μΩ · cm) Before heat treatment
13.221 13.04% After heat treatment
(Self copper coating) 2.275 75.78%

As shown in Table 3, it can be seen that Cu contained in the Fe-Cu alloy (diffusion) was eluted to the surface by heat treatment, and thus had higher electrical conductivity (specific resistance and electrical conductivity) than before the heat treatment.

10: alloy material 12: main body (iron-copper alloy)
14 coating layer (copper layer)

Claims (12)

Iron-copper alloy; And
Copper-coated iron-copper alloy material, characterized in that it comprises a copper layer formed on the surface of the iron-copper alloy.
The method of claim 1,
The copper layer is a copper-coated iron-copper alloy material, characterized in that the iron-copper alloy is heat-treated, the copper contained in the iron-copper alloy is eluted to the surface.
The method of claim 2,
The copper layer is a copper-coated iron-copper alloy material, characterized in that the iron-copper alloy is formed by heat treatment at a temperature of 1,100 ℃ ~ 1,450 ℃.
The method according to any one of claims 1 to 3,
The iron-copper alloy,
Iron 55-95 atomic%; And
Copper-coated iron-copper alloy material, characterized in that containing 5 to 45 atomic% copper.
The method according to any one of claims 1 to 3,
The iron-copper alloy,
80 to 95 atomic percent iron; And
5 to 20 atomic percent copper,
A copper coated iron-copper alloy material characterized by a thermal conductivity of at least 70 W / m · K.
The method according to any one of claims 1 to 3,
The copper layer has a thickness of 5nm ~ 20㎛ copper-coated iron-copper alloy material.
The method according to any one of claims 1 to 3,
The copper-coated iron-copper alloy material has a specific resistance of 2.4 μΩ · cm or less.
A first step of obtaining an iron-copper alloy; And
And a second step of forming a copper layer on the surface of the iron-copper alloy.
The method of claim 8,
The second step is a copper-coated iron-copper, characterized in that by heat-treating the iron-copper alloy obtained in the first step, the copper contained in the iron-copper alloy to elute to the surface to form a copper layer Method for producing alloy material.
The method of claim 9,
The second step is a method of producing a copper-coated iron-copper alloy material, characterized in that the iron-copper alloy obtained in the first step at a temperature of 1,100 ℃ ~ 1,450 ℃.
An article comprising the copper-coated iron-copper alloy material according to any one of claims 1 to 3.
The method of claim 11,
The product is a connector, a terminal, a ground wire or an electrode.

Images