KR20180113487A - Iron-copper alloy having high thermal conductivity and method for manufacturing the same - Google Patents

Abstract

The present invention provides a high thermal conductivity iron-copper alloy (Fe-Cu Alloy) and a method of manufacturing the same. The present invention provides an iron-copper alloy containing 55 to 95 atomic% of iron and 5 to 45 atomic% of copper. The present invention also provides an iron-copper alloy manufacturing method including a first step of preparing a melting furnace; a second step of adding iron and copper to the melting furnace and performing dissolution and molten metal formation so as to contain 55 to 95 atomic% of iron and 5 to 45 atomic% of copper based on the weight of the iron-copper alloy; a third step of stabilizing the molten metal; and a fourth step of pouring the stabilized molten metal into a casting mold and performing casting. The present invention provides an iron-copper alloy that is an iron-based alloy containing iron as a main component and having high thermal conductivity and mechanical properties along with, for example, an electromagnetic-wave shielding property and a soft magnetic property, which can be widely used for metal parts and electronic parts and machine parts.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-thermal-conductivity iron-copper alloy and a method of manufacturing the same. BACKGROUND ART [0002]

The present invention relates to a novel iron-copper (Fe-Cu) alloy containing an appropriate amount of copper (Cu) in an iron (Fe) base and having a high thermal conductivity and excellent mechanical properties, electromagnetic wave shielding property and softness - Copper alloys and methods for their production.

The metal-related manufacturing industry has been replaced by lightweight materials such as aluminum alloys in steel materials. Aluminum alloys are widely used for various applications in various industrial fields because of their excellent heat conductivity, corrosion resistance and ductility as well as light weight. Aluminum alloys are highly thermally conductive, allowing rapid cooling of heat to minimize deformation and warpage of molded parts. Accordingly, the aluminum alloy is usefully used as a mold material for injection molding or die casting.

For example, Korean Patent Laid-Open Publication No. 10-2015-0046014 and Korean Patent Registration No. 10-1606525 disclose a technique relating to an aluminum alloy for die casting. Aluminum alloys are based on aluminum (Al) and contain small amounts of silicon (Si), iron (Fe), manganese (Mn) and magnesium (Mg) ) Type alloy is widely used as a die-casting mold material.

However, aluminum alloys have low mechanical properties such as strength and abrasion resistance. Accordingly, beryllium-copper (Be-Cu) alloys having high thermal conductivity and corrosion resistance as well as excellent mechanical properties such as strength and abrasion resistance are attracting attention as mold materials. For example, Japanese Laid-Open Patent Publication Nos. 2003-003246, 10-2012-0048287 and 10-2015-0053814 disclose a technique relating to a beryllium-copper (Be-Cu) alloy .

Beryllium-copper (Be-Cu) alloys are practical alloys with high strength and high thermal conductivity, which are useful as die-casting mold materials. Beryllium-copper (Be-Cu) alloys are obtained by melting and casting beryllium (Be) and copper (Cu) in most cases, followed by repeated hot and cold calcining and annealing, And cobalt (Co) is added to the cobalt. However, beryllium-copper (Be-Cu) alloys are difficult to cast continuously, and beryllium (Be) and copper (Cu) raw materials themselves are high in price, resulting in poor economical efficiency. As a result, beryllium-copper (Be-Cu) alloys are used in high-priced products due to their high price, which is problematic in that the versatility is poor.

Korean Patent Publication No. 10-2015-0046014 Korean Patent Publication No. 10-1606525 JP-A-2003-003246 Korean Patent Publication No. 10-2012-0048287 Korean Patent Publication No. 10-2015-0053814

Accordingly, the present invention provides a novel iron-based alloy composition capable of replacing a conventional beryllium-copper (Be-Cu) alloy, an iron-copper (Fe-Cu) alloy having improved properties, There is a purpose in doing.

Specifically, the present invention relates to an iron-copper (Fe-Cu) alloy having high thermal conductivity and mechanical properties including an appropriate amount of copper (Cu) in an iron (Fe) base and having electromagnetic wave shielding property and softness, And a manufacturing method thereof. The present invention also provides a use of the iron-copper (Fe-Cu) alloy and a material containing the iron-copper (Fe-Cu) alloy.

According to an aspect of the present invention,

55 to 95 atomic% of iron; And

Copper alloy containing 5 to 45 atomic% of copper.

Further, according to the present invention,

80.5 to 95 atomic% of iron; And

5 to 19.5 atomic percent of copper,

There is provided an iron-copper alloy having the following properties (a) to (c).

(a) Thermal conductivity of 70 W / m K or more

(b) Tensile strength 300 N / mm2 or more

(c) Hardness more than 100 HB

According to an exemplary embodiment, the iron-copper alloy according to the present invention is in the form of a spherical particle, and may have a size of 0.1 mu m to 150 mu m.

Further, according to the present invention,

A first step of preparing a melting furnace;

A second step of adding iron and copper to the melting furnace so as to include 55 to 95 atomic% of iron and 5 to 45 atomic% of copper in the iron-copper alloy to form a molten iron;

A third step of stabilizing the molten metal; And

And a fourth step of injecting the stabilized molten metal from a casting mold and casting the molten metal.

According to one embodiment, the method of manufacturing an iron-copper alloy according to the present invention further comprises a fifth step of re-dissolving the casting obtained through the fourth step and then spraying to obtain iron-copper alloy particles in powder form .

According to a preferred embodiment, the first step includes a surface treatment step of forming a porous impurity absorption layer on the inner surface of the melting furnace. At this time, it is preferable that the porous impurity absorbing layer includes zirconium silicate.

According to the present invention, there is provided a novel iron-based alloy capable of replacing a conventional beryllium-copper (Be-Cu) alloy. The present invention has the effect of providing an iron-copper alloy having excellent thermal conductivity and mechanical properties and high productivity and economy, as an amorphous perfect alloy in which iron (Fe) is melted and alloyed with an appropriate amount of copper (Cu). In addition, the present invention has an effect of providing iron-copper alloy which can be widely used for metal parts, machine parts, and the like as well as high thermal conductivity, electromagnetic wave shielding and soft magnetic properties.

1 is a BH curve of an Fe-Cu alloy produced according to an embodiment of the present invention.
2 is a SEM photograph of Fe-Cu alloy particles prepared according to an embodiment of the present invention at various magnifications.
3 shows the results of EDS analysis of the Fe-Cu alloy particles prepared according to the embodiment of the present invention.
4 shows the results of EDS analysis of the Fe-Cu alloy particles produced according to the embodiment of the present invention.
5 shows the results of EDS analysis of the Fe-Cu alloy particles produced according to the embodiment of the present invention.
6 is an SEM photograph of a particle specimen according to a comparative example.

The term "and / or" used in the present invention is used to mean at least one of the constituents listed before and after. The term "one or more" as used in the present invention means one or more than two.

According to a first aspect of the present invention, there is provided an iron-copper alloy having iron (Fe) as a main component and having a novel alloy composition. The present invention provides a method for producing the iron-copper alloy according to the second aspect. Further, according to a third aspect of the present invention, as the use of the iron-copper alloy, there is provided a material containing at least the iron-copper alloy. The material may be selected from, for example, a mold material and a material for a 3D printer.

The iron-copper alloy according to the present invention is an iron-based alloy containing iron (Fe) and copper (Cu) and having a higher content of iron (Fe) than copper (Cu) (Fe) 55 to 95 atomic% (atomic%) and copper (Cu) 5 to 45 atomic%. The "atomic%" of the content unit used in the present invention is based on the total atomic amount of iron (Fe) and copper (Cu) (sum of Fe and Cu), which is also referred to as " Volume% " That is, in the present invention, atomic% = volume% can be expressed.

According to a preferred embodiment, the iron-copper alloy according to the present invention does not contain iron and other metal elements other than copper. Further, the iron-copper alloy according to the present invention may contain impurities such as carbon (C) and oxygen (O) as unavoidable impurities, but these impurities are very small. Impurities may inevitably be contained, for example, at 0.1 atomic% (0.1 vol%) or less or 0.01 atomic% or less.

The iron-copper alloy according to the present invention contains an appropriate amount of copper in iron, so that the advantages of iron and the advantages of copper are well coordinated and have improved properties. The iron-copper alloy according to the present invention has at least high thermal conductivity and mechanical properties. Specifically, it has higher thermal conductivity and elasticity than conventional iron alloys. In addition, it has higher hardness and wear resistance than conventional copper alloys. In addition, it has high economic efficiency by using low-priced iron as a base (main component), and it can be used for various purposes due to its electromagnetic wave shielding property and soft magnetic property due to proper composition (content) of iron and copper. For example, it can be used as a precision component such as a solenoid, an electromagnetic wave shielding material, and a material for a 3D printer.

Hereinafter, a method for producing an iron-copper alloy according to the present invention will be described, and an embodiment of the iron-copper alloy according to the present invention will be described. The manufacturing method described below easily implements the production of the iron-copper alloy according to the present invention. However, the iron-copper alloy according to the present invention is not limited to those produced by the manufacturing method described below.

A method for producing an iron-copper alloy according to the present invention (hereinafter referred to as "production method") comprises a first step of preparing a melting furnace, a second step of adding iron and copper to the melting furnace, , A third step of stabilizing the molten metal, and a fourth step of casting the stabilized molten metal into a casting mold. In addition, the manufacturing method according to the present invention may further include a fifth step of obtaining iron-copper alloy particles in powder form from the casting obtained through the fourth step as an optional step. An embodiment of each process will be described as follows.

[1] Preparation of melting furnace (first step)

As described above, the iron-copper alloy according to the present invention contains 55 to 95 atomic% of iron and 5 to 45 atomic% of copper. The alloy composition specified in the present invention is not a theoretical molten alloy composition. That is, the ratio exceeds the amount of iron that can theoretically be alloyed. Such an alloy composition can be realized at the time of production of the parent alloy through sintering, but it is difficult to form the amorphous complete alloy in the melting method through melting (melt). Generally, iron and copper can be made of a molten alloy when the iron content is lower than copper (e.g., less than 2.5 volume% Fe). However, in the case of the alloy composition specified in the present invention, a two-phase separation of the Fe-rich phase and the Cu-rich phase occurs in the molten metal, segregation (one of the metals is concentrated in one place) It is difficult to achieve.

The present inventors have conducted numerous studies for achieving a complete molten alloy with a high iron content. As a result, it has been found that when the content of copper is appropriately adjusted, the content of impurities is minimized, and / or the melting process is varied, A complete molten alloy was formed. According to the present invention, it has been found that a complete molten alloy is formed when the improvement of the melting furnace and / or the method of introducing the raw material in the melting process are improved according to one embodiment.

In this first step, one embodiment for solving the above problems is provided. According to the first step, a melting furnace for forming molten iron and copper is prepared, and the melting furnace uses a high-frequency induction heating furnace capable of rapid dissolution through rapid heating. It is preferable to use a ceramic melting furnace containing magnesium as a main component. As the ceramic melting furnace, for example, a ceramic produced mainly from magnesium oxide by high temperature and calcination may be used.

According to a preferred embodiment, the melting furnace is used by forming a porous impurity absorption layer on the inner surface thereof. Specifically, the first step includes a surface treatment step of 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. At this time, the impurity absorbing layer is formed on the whole or a part of the inner surface of the melting furnace, and specifically, it may be formed on at least the inner bottom surface and / or the inner surface of the melting furnace.

Further, the impurity absorbing layer includes at least a dopant absorbing agent. Specifically, in the surface treatment step, an absorbing layer composition including an impurity absorbing agent, a resin and a solvent may be applied to the inner surface of the melting furnace and then fired to form a porous impurity absorbing layer. According to the present invention, impurities (for example, C, O and the like) contained in the molten iron-copper are absorbed and removed by the porous impurity absorption layer, and even in the non-theoretical alloy composition, Complete alloy is achieved. Such a porous impurity absorbing layer may have a thickness of, for example, 0.5 mm to 2 mm, but is not limited thereto.

The impurity absorber is not particularly limited as long as it can absorb and remove impurities (for example, C, O, etc.) contained in the iron-copper molten metal. The impurity absorbing agent is in the form of powder, and it can be used, for example, having a size of 50 to 500 mu m. The impurity absorber may be selected from metal oxides and / or metals, and it preferably contains at least one selected from zirconium silicate and aluminum (Al). It is more preferable to use both of zirconium silicate and aluminum (Al) as the impurity absorber. At this time, the aluminum (Al) having a high purity of 99.8 wt% or more can be used. As the impurity absorber, zirconium silicate and aluminum (Al) as described above can completely remove impurities in the molten metal as compared with other metal oxides or metals, which is preferable in the present invention. The zirconium silicate and aluminum (Al) can specifically remove impurities in the molten metal to form a high-purity alloy melt containing only iron and copper. This can be confirmed by the following examples.

The resin is not particularly limited as long as it has adhesiveness and may be any one capable of providing an initial adhesive force between the inner surface of the melting furnace and the impurity absorbing layer while aggregating the impurity absorbents in powder form. In addition, the resin is removed by heat at a high temperature due to firing, thereby imparting porosity to the impurity absorbing layer. The resin may be selected from synthetic resins and / or natural resins. The resin may be a solid phase and / or a liquid phase, and may be, for example, at least one polymer selected from an acrylic type, a vinyl type, an epoxy type, a urethane type, a silicone type, an olefin type, an ester type and a rubber type and / Can be selected.

The resin is preferably a butadiene-styrene-alkyl methacrylate copolymer. Specific examples of the butadiene-styrene-alkyl methacrylate copolymer include butadiene-styrene-methyl methacrylate copolymer, butadiene-styrene-ethyl methacrylate copolymer and / or butadiene-styrene-butyl methacrylate copolymer Coalescence, and the like. In one example, the butadiene-styrene-alkyl methacrylate copolymer may have a particle size of 50 nm to 500 nm. When a butadiene-styrene-alkyl methacrylate copolymer is selected as the resin and a nano-sized resin is used, it can be quickly removed through firing and evenly dispersed between the powdery impurity absorbers. This improves the cohesion force between the impurity absorbers, as well as forms a homogeneous and fine porous structure in the impurity absorbing layer, thereby improving the ability to remove impurities.

The solvent is for dispersibility and applicability, and it can be selected from a hydrocarbon system. The solvent may be selected from, for example, alcohols and / or ketones.

In addition, the absorbent layer composition may comprise, in one example, from 50 to 80% by weight of the impurity absorber, from 5 to 20% by weight of the resin and from 15 to 40% by weight of the solvent. At this time, if the content of the impurity absorbent is less than 50% by weight, the ability to remove impurities may be insufficient. If the content exceeds 80% by weight, the porosity and coating property may be deteriorated. If the content of the resin is less than 5% by weight, the porosity and adhesiveness may be deteriorated. If the content of the resin is more than 20% by weight, the content of the impurity absorbent may be relatively low and the ability to remove impurities may be insufficient. The solvent is preferably in the above range in consideration of dispersibility and coatability.

When a porous impurity absorbing layer is formed on the inner surface of the furnace through the first step as described above, the impurities contained in the molten metal are absorbed and removed in the melting process to form a complete iron-copper alloy of homogeneous phase, It is possible to effectively obtain a high-purity iron-copper alloy containing substantially no copper.

[2] Dissolution (Second Step)

And an alloy material of iron and copper is charged into the above melting furnace. At this time, iron can be pure iron of high purity, and the copper can use electrolytic copper of high purity. The melting furnace can be warmed 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 good to dissolve iron and copper by rapidly raising the melting furnace through high frequency induction heat and keeping it at about 1,520 ℃ ~ 1,650 ℃. In this dissolution process, stirring may proceed.

In the second step, iron and copper are added to the melting furnace so as to include 55 to 95 atomic% (or volume%) of iron and 5 to 45 atomic% (or volume% Copper is added and melted to form a molten metal. Specifically, when the total amount of iron and copper in the melting furnace is 55 to 95% by volume of iron and 5 to 45% by volume of copper (i.e., iron: copper = 55 to 95: 5 to 45% by volume) can do. At this time, if the content of copper is less than 5 atomic% (5 vol%), for example, thermal conductivity, corrosion resistance and / or electromagnetic wave shielding property may become insignificant. If the content of copper exceeds 45 atomic% (45 vol%), the content of iron may be relatively low and mechanical strength such as hardness and / or abrasion resistance may be lowered.

According to a preferred embodiment of the present invention, in consideration of the above-described points, in the second step, the total amount of the iron-copper alloy to be contained in the melting furnace is set so as to include 80.5 to 95 atomic percent of iron and 5 to 19.5 atomic% It is preferable to add iron and copper to form a molten metal. That is, when the total amount of iron and copper in the melting furnace is 80.5 to 95% by volume of iron and 5 to 19.5% by volume of copper (i.e., iron: copper = 80.5 to 95: 5 to 19.5 by volume) . When having such a preferable alloy composition, it has excellent thermal conductivity, mechanical properties, electromagnetic wave shielding property and / or soft magnetic property.

According to one embodiment of the present invention, when iron and copper are introduced into the melting furnace, iron and copper are initially charged at a volume ratio of 1: 1, rapidly dissolved while stirring, and then iron is added thereto, Composition can be obtained. That is, rather than having the alloy composition through a single injection, it is preferable to initially add iron and copper in a volume ratio of 1: 1 and then to add the iron composition to the alloy composition to obtain a homogeneous iron-copper alloy composition desirable. In addition, it is more preferable to intermittently inject the iron gradually. That is, it is advantageous to add a small amount of iron over several times to form a homogeneous alloy composition.

In the second step (dissolving step), a deoxidizing agent may be added to the melting furnace to conduct deoxidation (oxidation prevention). In addition, in the second step (dissolution step), a flux can be further added as usual. At this time, the deoxidizer and the flux may be those conventionally used. The deoxidizer may be, for example, 99.8 wt% 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 .

[3] Stabilization (third step)

Thereby stabilizing the molten metal formed through the dissolution. Stabilization can be performed by cutting off the power supply to the melting furnace and leaving the molten metal in the melting furnace for a predetermined time. At this time, the stabilization may be performed by keeping the temperature of the molten metal at, for example, 1,450 ° C to 1,520 ° C. By such stabilization, homogenization of iron and copper can be achieved.

[4] Casting (fourth step)

The stabilized molten metal is injected into a casting mold and cast into a certain type of alloy casting. The fourth step (casting) follows the ordinary process. The casting mold is not particularly limited, and it may have the shape of an ingot and a casting mold, or may have a shape of a practical product in some cases. In addition, the casting mold may have a cooling function as usual.

In addition, the casting obtained through the fourth step can be post-treated through a process such as ordinary heat treatment and / or cooling. The casting may be post-treated through a process such as annealing, normalizing, quenching and / or tempering, for example. Such a post-treatment can be appropriately selected depending on the application purpose and the product. For example, in the case of products requiring mechanical strength (such as tensile strength and hardness), quenching and tempering may proceed. In addition, the casting has various shapes through re-dissolution and / or post-processing, and can be processed into an actual product or semi-finished product.

[5] Particle formation (fifth step)

This fifth step is an optional step through which a powdered iron-copper alloy can be obtained. According to the fifth step, the casting obtained through the fourth step (casting) is remelted and then sprayed to obtain powdery iron-copper alloy particles. Specifically, the fifth step may include a redissolving step of redissolving the casting and a granulating step of spraying the redissolved lysate to obtain powdered iron-copper alloy particles.

At this time, in the redissolution step, the same melting furnace as in the first step may be used. Further, in the re-dissolution step of the fifth step, it is preferable to redissolve the iron-copper alloy in a vacuum melting furnace in order to prevent oxidation of the iron-copper alloy. That is, a vacuum furnace can be used as the melting furnace. In this vacuum furnace, the casting can be redissolved at 1,600 ° C to 1,700 ° C. The granulation step may be performed by spraying the redissolved lysate at 1,400 ° C to 1,500 ° C to form a powder. At this time, the granulated powder may have a size of, for example, 0.1 mu m to 150 mu m. The powdery iron-copper alloy particles thus obtained may preferably have a spherical particle shape.

According to the manufacturing method of the present invention described above, a complete alloy is formed without segregation even in the non-theoretical alloy composition containing 55 to 95 atomic% of iron and 5 to 45 atomic% of copper. In addition, the iron-copper alloy produced according to the present invention has a high thermal conductivity and mechanical properties (tensile strength, hardness, abrasion resistance, etc.) as described above, Shielding property and soft magnetic property, so that it can be used for various purposes.

According to a preferred embodiment, the iron-copper alloy according to the invention comprises from 80.5 to 95 atomic% (or vol%) of iron and from 5 to 19.5 atomic% (or% by volume) of copper. More specifically, it may include 82.5 to 90.5 atomic% of iron and 9.5 to 17.5 atomic% of copper. When such an alloy composition is used, properties such as thermal conductivity, mechanical properties, electromagnetic wave shielding properties and / or soft magnetic properties are effectively improved.

The iron-copper alloy according to the present invention preferably has the following properties (a) to (c). In the case of having the following properties (a) to (c), it can be used for molds such as injection molding and die casting, as well as for 3D printer materials.

(a) Thermal conductivity of 70 W / m K or more

(b) Tensile strength 300 N / mm2 or more

(c) Hardness more than 100 HB

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

The thermal conductivity may be, for example, 70 to 150 W / mK. In addition, the tensile strength may have a specific range of 300 to 1,350 N / mm < 2 >. And the hardness is Brinell hardness, which may have a specific example of 100 HB to 400 HB. Each of these physical properties can be optimized depending on the application purpose. For example, in the case of tensile strength and hardness, it can be increased through post-treatment as described above (such as quenching, tempering and tempering), and the tensile strength is higher than 500 N / Or more.

Thus in the exemplary embodiment, the iron according to the present invention copper alloys can have a permeability (透磁率) of (d) 45 ~ 650 _m m with the physical properties of (a) to (c). The permeability depends on a conventional measuring method for a magnetic body (metal, etc.), which is a value measured at a low frequency of 50 Hz.

Further, the iron-copper alloy according to the present invention preferably has a spherical particle shape. The spherical particle phase can be realized through the fifth process. At this time, the iron-copper alloy according to the present invention has a spherical particle shape, and may have a size of, for example, 0.1 탆 to 150 탆. As described above, in the case of a spherical particle image, it can be usefully used as a material for a 3D printer. In the present invention, " spherical " does not mean only a complete spherical shape, but includes a complete spherical as well as a quasi-spherical.

In the present invention, " spherical particles " means that iron and copper are uniformly distributed in the alloy and a complete molten alloy is formed without the iron-copper alloy being segregated (unevenly) even in the non-theoretical alloy composition . In this respect, "spherical particles" have a technical significance. That is, when a complete molten alloy is not formed, it is difficult to have a spherical particle shape through injection. In addition, in the present invention, the "spherical particles" have technical significance in that iron-copper alloy moldings having a uniform composition can be processed through redissolution.

Meanwhile, the iron-copper alloy according to the present invention can be used in various fields and applications, and the application field and application are not particularly limited. The iron-copper alloy according to the present invention can be used as an electronic component, a precision machine component, a high-temperature machine component, and a material for a 3D printer as well as a mold material as described above. The iron-copper alloy according to the present invention can be widely applied not only to elastic materials, shielding materials, antibacterial materials, sensor materials and surgical medical instruments, but also to energy fields and paints.

Hereinafter, examples and comparative examples of the present invention will be exemplified. The following examples are provided to illustrate the present invention in order to facilitate understanding of the present invention, and thus the technical scope of the present invention is not limited thereto. In addition, the following comparative example is not meant to be a prior art, but is provided for comparison with an embodiment only.

[Example 1]

<Melting furnace>

A ceramic melting furnace containing magnesium as a high-frequency induction heat melting furnace was prepared. Thereafter, a porous impurity absorbing layer was formed on the inner wall surface and the bottom of the prepared melting furnace. The porous impurity absorbing layer is formed by applying an absorbing layer composition comprising 65 wt% of an impurity absorbing agent, 15 wt% of a resin and 30 wt% of a solvent based on the total weight of the composition to a thickness of about 1 mm and then heating at a temperature of about 1,150 [ Followed by firing. At this time, zirconium silicate (ZrSiO ₄ ) and Al powder were used as the impurity absorber, butadiene-styrene-methyl methacrylate copolymer was used as the resin, and isopropyl alcohol was used as the solvent.

<Melting / stabilization / casting>

Iron (purity of about 99.9% by weight of pure iron) and copper (purity of about 99.9% by weight of electrolytic copper) were initially charged into the above-mentioned melting furnace at a volume ratio of 1: 1. At this time, a deoxidizing agent (Al) was added intermittently in the dissolution process and proceeded with deoxidation. After the complete dissolution of iron and copper was confirmed through visual observation, iron was added little by little to the melting furnace in order to increase the content of iron and completely dissolved at a temperature of about 1,550 ° C. Thereafter, the power source of the melting furnace was shut off, and the temperature was allowed to stand until the temperature of the molten metal reached about 1,500 캜 to be stabilized. Next, the stabilized molten metal was injected into a casting mold and then cooled to obtain an Fe-Cu alloy ingot.

[Example 2 and Example 3]

In contrast to Example 1, in order to make the final alloy composition (atomic% of Fe and Cu) different, the same procedure as in Example 1 was carried out except that the amount of iron added was varied during the dissolution process. Gt; Fe-Cu &lt; / RTI &gt; alloy ingot was obtained.

[Comparative Example 1]

A porous impurity absorbing layer was formed on the inner surface of the melting furnace, and the same procedure as in Example 1 was performed except that the kind of the impurity absorbing agent was different. Specifically, the procedure of Example 1 was repeated, except that zirconium silicate (ZrSiO ₄ ) was used as the impurity absorber and zirconium oxide (ZrO ₂ ) was used instead of Al.

[Comparative Example 2]

Compared with the above Example 1, in Comparative Example 2, iron and copper were introduced into a melting furnace at a volume ratio of 9: 1 at a time, and the inside of the furnace was melted without forming a porous impurity absorbing layer. .

The Fe-Cu alloy specimen thus obtained was analyzed for components as follows, and the results are shown in Table 1 below. The thermal conductivity, tensile strength, hardness and permeability of each alloy specimen were evaluated, and the results are shown together in Table 1 below. The thermal conductivity is a method of measuring the thermal conductivity of a metal sample. The density, specific heat and thermal diffusivity of each alloy specimen were measured and evaluated according to ASTM E1461 (Laser flash: Thru-plane). At this time, all tests were conducted at a temperature of 25 ° C. The tensile strength was evaluated in accordance with KS B 0801, and the hardness was evaluated by Brinell Hardness according to KS B 0805. The permeability was evaluated at a frequency of 50 Hz using a permeability meter (product of Japan Electronics and Engineering Co., Ltd., model name BHU-60).

<Component analysis>

The alloy specimen, whose weight was measured, was placed in a beaker made of glass and dissolved in 10 mL of aqua regia (hydrochloric acid + sulfuric acid aqueous solution). Fe and Cu were quantitatively analyzed by high-frequency inductively coupled plasma emission spectroscopy (ICP-AES) according to the following measurement conditions and converted into the concentration in the sample.

* Measurement conditions of ICP-AES

- Measuring device: PerkinElmer Optima 5300DV

- Measured wavelength: 238.204 nm (Fe), 327.393 nm (Cu)

- Quantitative method: Internal standard method

                 &Lt; Evaluation of composition and physical properties of Fe-Cu alloy >
Remarks
impurities
Absorbent Composition
(atom%)
Thermal conductivity
[W / mK]
The tensile strength
[N / mm &lt; 2 &
Brinell hardness
[HB]
Investment ratio
[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 occurrence 56.1 crack - - Comparative Example 2
- Segregation occurrence 47.3 crack - -

As shown in Table 1, the Fe-Cu alloy according to the Examples had a high thermal conductivity of 70 W / m · K or more as compared with Comparative Examples. In addition, it was found that the Fe-Cu alloy according to Examples had a tensile strength of 320 N / mm &lt; 2 &gt; or more and a hardness of 140 HB or more. At this time, a high tensile strength of 320 N / mm &lt; 2 &gt; or more means that the Fe alloy and the Cu alloy are uniformly distributed without being segregated. In addition, approximately 600 m _m , Which means that it has electromagnetic shielding ability. 1 shows the BH curve (magnetization curve) of an alloy according to Example 1, which means that it has soft magnetic properties.

On the contrary, in the comparative examples, it was found that a complete alloy was not formed and segregation occurred. Further, cracks were generated due to segregation when measuring tensile strength, and it was impossible to measure the tensile strength. In addition, in the case of the comparative examples, since the components are uneven due to segregation, it can not be accurately evaluated and is not shown in [Table 1]. Hardness and permeability were also not shown for the above reasons.

Table 2 below shows the results of evaluation of physical properties according to the post-treatment, showing the results of the pre-treatment and the post-treatment of the same alloy specimen as in Example 2. [ Annealing, normalizing, quenching and tempering were carried out according to a conventional method.

         &Lt; Results of physical property change due to post-treatment of Fe-Cu alloy >
Remarks
Before processing
(Example 2) After processing
Annealing tempering metal Quenching (900 ° C)
+ Tempering Quenching (1,050 ℃)
+ Tempering The tensile strength
[N / mm &lt; 2 & 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, it was found that the Fe-Cu alloy was changed in physical properties by the post-treatment. For example, when quenching (and tempering) was carried out 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 to improve the mechanical strength before the treatment. In this way, it means that a complete alloy is formed, as the mechanical strength is improved by the heat treatment like a general pure single metal (pure iron, etc.).

[Examples 4 to 6]

In order to make the final alloy composition (atomic% of Fe and Cu) different from that of Example 1, the same procedure as in Example 1 was carried out except that the addition amount of iron was changed during the dissolution process, Fe-Cu alloy ingot according to (4-6) was obtained. In addition, in these embodiments, the Fe-Cu alloy ingot obtained through casting is granulated as follows to prepare powdered Fe-Cu alloy particles.

First, an Fe-Cu alloy ingot according to each of Examples (4 to 6) obtained through casting was put into a melting furnace for high-frequency induction heat, and the maximum power was applied to redissolve it at a temperature of about 1,650 ° C. At this time, the melting furnace was kept vacuum to prevent oxidation. Next, the redissolved lysate was sprayed using a sprayer to be granulated. At this time, the injection chamber was maintained in an argon (Ar) gas atmosphere to prevent oxidation, and the melt was sprayed at a temperature of 1,450 ° C.

FIGS. 2 to 5 show SEM photographs and EDS analysis results of powdery Fe-Cu alloy particles produced according to each of Examples 4 to 6. FIG. 2 is a SEM photograph of Fe-Cu alloy particles according to Example 4 at various magnifications, and FIG. 3 shows the results of EDS analysis of Fe-Cu alloy particles according to Example 4. FIG. FIG. 4 shows the results of EDS analysis of the Fe-Cu alloy particles according to Example 5. FIG. 5 shows the results of EDS analysis of the Fe-Cu alloy particles according to Example 6. FIG.

As shown in FIGS. 2 to 5, the Fe-Cu alloy particles prepared according to each of Examples 4 to 6 are fine particles of 30 μm or less and almost complete spherical shapes. 3 shows that the distribution of Fe and Cu (Fe: red, Cu: green) shows that Fe and Cu are uniformly distributed without being segregated have. In this case, among the three photographs shown in the lower part of FIG. 3, the middle photograph shows the distribution of Fe (red), the rightmost photograph shows the distribution of Cu (green), and the leftmost photograph shows the distribution of Fe and Cu . Thus, the uniform distribution of Fe-Cu alloy particles with perfect spherical morphology means that Fe and Cu are completely alloyed.

6 is an SEM photograph of a particle specimen sprayed using the ingot according to Comparative Example 2. Fig. As shown in Fig. 6, in the case of Comparative Example 2, the particle shape was uneven because of segregation. This means that a complete alloy has not been achieved.

Claims (5)

55 to 95 atomic% of iron; And
Copper and 5 to 45 atom% of copper.
80.5 to 95 atomic% of iron; And
5 to 19.5 atomic percent of copper,
Wherein the iron-copper alloy has a thermal conductivity of 70 W / m · K or more.
A first step of preparing a melting furnace;
A second step of adding iron and copper to the melting furnace so as to include 55 to 95 atomic% of iron and 5 to 45 atomic% of copper in the iron-copper alloy to form a molten iron;
A third step of stabilizing the molten metal; And
And a fourth step of casting the stabilized molten metal into a casting mold,
The first step includes a surface treatment step of forming a porous impurity absorption layer on the inner surface of the melting furnace,
Wherein the porous impurity absorbing layer includes an impurity absorbing agent that absorbs impurities contained in the molten metal,
Wherein the impurity absorbing agent is composed of zirconium silicate and aluminum (Al).
The method of claim 3,
Further comprising a fifth step of re-dissolving the casting obtained through the fourth step and spraying the iron-copper alloy particles to obtain iron-copper alloy particles.
The method of claim 3,
The second step is to add and dissolve iron and copper to the melting furnace so as to have an iron-copper alloy composition including 80.5 to 95 atomic% of iron and 5 to 19.5 atomic% of copper to form a molten metal,
The iron and copper were initially added to the melting furnace at a volume ratio of 1: 1 and dissolved while stirring. Then, iron was added thereto to prepare an iron-copper alloy including 80.5 to 95 atomic% of iron and 5 to 19.5 atomic% Wherein the molten metal is formed so as to have a composition.

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