KR101779715B1 - BCC HEA-LEA complex foam with open pores made by spinodal decomposition and manufacturing method for the foam - Google Patents

Abstract

TECHNICAL FIELD The present invention relates to a BCC HEA-LEA composite structure porous body having a spinodal decomposition pore structure through multistage phase separation, and a method for producing the same. More particularly, the present invention relates to a BCC HEA- BCC HEA-LEA composite structure porous body prepared by selective dissolving of separated dendritic BCC HEA and Zr-rich BCC LEA with dendritic spinodal decomposition structure and HCP LEA of M-rich HCC LEA ≪ / RTI >
The three-phase separated alloy of the present invention constituted as described above can exhibit not only excellent mechanical and thermal properties of BCC HEA but also a cocktail effect according to a unique composite structure with the polyphase LEA. Further, in the case of the porous body of the present invention, By having a unique spinodal decomposition pore structure, it exhibits high physical properties such as high elongation and high activity as well as high strength properties of HEA.

Description

(BCC HEA-LEA complex foam with open pores made by spinodal decomposition and manufacturing method for the foam)

The present invention relates to a high entropy alloy (HEA) and a low entropy alloy (LEA) having a body-centered cubic (BCC) crystal structure having a spinodal decomposition pore structure through multi- The present invention relates to the production of a composite structure porous body, and more particularly, to a method of manufacturing a porous structure by sequentially forming a spinodal decomposition due to the occurrence of uphill-diffusion due to instability of free energy, And has a unique spinodal decomposition pore structure, and a method for producing the same.

HEA is an alloy system in which multicomponent elements are composed of similar fractions and multicomponent elements act as main elements. Due to the similar atomic fractions between multicomponent main elements and elements, large constituent entropy is induced, Is formed in place of an intermetallic compound or an intermediate compound formed by a single solid solution.

Unlike LEA, which has more than 50 at.% Of a single component element in a common commercial alloy, the HEA solid solution has complex components due to the large constituent entropy and constituent elements induced by the constituent elements, An internal stress condition occurs, which causes severe lattice strain. Also, through the above stress conditions and lattice strain, the constituent elements have a relatively slow diffusion rate in the lattice, and the precipitation of the second phase is delayed at high temperature, so that good mechanical properties and phase stability are maintained at a high temperature. The characteristics of HEA are as follows: 1) at least three alloying elements, 2) a similar atomic size difference in which the atomic radius difference (ΔR) between elements is less than ± 10%, and 3) a mixed enthalpy difference (ΔHmix) / mole of atoms. < / RTI > Especially, the high entropy alloy (BCC HEA) having a body-centered cubic crystal structure is known to have superior mechanical properties over superalloy which is widely used at a high temperature of 1000 ° C or higher.

However, research on HEA is in the early stage of development, so unlike conventional commercial alloy systems, only the development of alloy systems with a single solid phase is focused on, and research on character control through second phase control is very limited . Especially, spinodal decomposition structure due to the generation of despreading due to instability of free energy in an alloy system having a solubility gap has not yet been reported in HEA. In addition to having such a unique microstructure, HEA has excellent mechanical and thermal It is necessary to study alloys showing physical properties. In addition, the porous alloy containing pores inside the matrix has not only the mechanical properties such as excellent elongation and energy absorption ability but also unique characteristics such as large surface area while maintaining the characteristics of the existing metal structural materials, Although many studies have been carried out in the field of materials, there have been no studies on the development of porous alloys having HEA as a main component while maintaining the above microstructure.

[Document 1] Intermetallics. 2010. "Refractory high-entropy alloys." O.N. Senkov, 5 others, 1758-1765 [Literature 2] The Journal of The Minerals, Metals & Materials Society. 2012. "Alloy Design and Properties Optimization of High-Entropy Alloys." Y. ZHANG and others, 830-838

Disclosure of Invention Technical Problem [8] Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and it is an object of the present invention to provide a method for producing a dendritic phase comprising a first phase of BCC HEA material grown in the form of a dendritic phase during solidification, A second phase of a BCC LEA material discharged into the interspace region and a second phase having a large positive (+) mixture relationship with the first and second phases, and a hexagonal closest packed, HCP) LEA and a third phase in the composite material of the present invention to form a first phase, BCC HEA, in a dendritic form, and a spinodal decomposition pore structure BCC LEA composite structure porous body of the second phase and a method for producing the same.

To achieve the above object, BCC HEA of dendritic structure and BCC LEA-HCP LEA spinodal decomposition structure of the dendritic region of the resin are three-phase separated composite material, which is a BCC HEA material in which various metal elements act as a common solvent A first phase; A first phase, a second phase of BCC LEA material separated by a large atomic radius and a difference in melting point; And a third phase of an HCP LEA material having an unmixed alloy composition due to a large positive (+) mixture relationship with alloys having a BCC crystal structure and causing a spinodal decomposition with the composition of the second phase .

In order to constitute the BCC HEA by acting as a common solute in a variety of metal elements, a similar atomic radius difference (ΔR) of ± 10% or less and a similar mixing enthalpy difference (ΔHmix) of ± 10 kJ / , And selecting the metal elements whose crystal structures are mostly BCC of the selected elements and synthesizing them at similar atomic ratios with a content deviation of less than ± 10 at.%. This is a general outline derived from the current knowledge of HEA, but is not limited to this, and any additional characteristics may be found for HEA, so any applicable HEA component, including characteristics to be revealed in the future, may be applied .

In addition, when an alloy element having a large difference in atomic radius and a low melting point relative to the elements constituting the BCC HEA is added, a single liquid phase can be formed in a high temperature liquid phase, but BEA HEA can not form a single solid solution during cooling, The composite material was designed to form a second phase BCC LEA in the dendritic region emitted within the solid solution base.

At the same time, an element having a large positive (+) mixed heat relationship with the elements constituting the BCC alloy was added to form a solubility gap to cause liquid phase separation between the phases, and liquid phase separation with BCC HEA The BCC LEA and the third phase, HCP LEA, in the dendritic region of the BCC HEA have a spinodal decomposition structure so that the development and release of the BCC LEA material and the spinodal decomposition are sequentially induced. Respectively.

In order to suppress the formation of an alloy having an extreme lamellar structure due to a large difference in density between the constituent elements of the third phase, which is a relatively light alloy element, and the BCC alloy, it is necessary to control the addition elements and composition of the BCC HEA, So as to form a composite structural material.

Further, in the present invention, as the main element group forming the first phase of the BCC HEA, element group I which is a BCC HEA forming element having an atomic weight smaller than Y, which is a representative element constituting the third phase, is Ti, V, Cr At least one element selected from Nb, Mo, Hf, Ta and W was selected as element group II, which is a BCC HEA-forming element having a large atomic weight.

As a main element of the second phase BCC LEA having a large melting point and an atomic radius difference with the BCC HEA material, Zr is characterized by including M as a main element forming a third phase which is a non-molten alloy with the BCC alloy do. In this case, M, which is an element forming the third phase, is a combination of Y and La, Ce, Nd, Gd, Tb, Dy, Ho and Er having a large amount of mixed heat with the alloying elements constituting the BCC HEA and BCC LEA. And at least one selected from the group consisting of lanthanides.

In addition, the present invention is characterized in that a group of formable elements of BCC HEA is classified into element groups I and II according to atomic weight, and one or more elements in element group I and II, respectively, and a group of BCC LEA having a large melting point and atomic radius difference Zr as an element, and finally a large positive (+) mixed heat relationship with BCC alloying elements, and by alloying M which acts as a main element of HCP LEA having BCC LEA and spinodal decomposition structure, Phase Separation Alloy composed of a first phase of BCC HEA and a second phase and a second phase of BCC LEA released into the dendritic region of the first phase and a third phase having a spinodal decomposition structure, .

The composition of the BCC alloy (BA) constituting the whole phase BCC alloy of the first and second phases is (BA) 100-xMx (0.1? X? 40 at.%) ). ≪ / RTI > When the content of M is less than 0.1 at.%, The phase separation phenomenon does not occur in the BCC alloy base, and when it exceeds 40 at.%, It is difficult to constitute a phase-separated composite material having a uniform composite structure.

Accordingly, the alloys of the present invention are firstly a composition region passing through a tie line where liquid separation of M-rich HCP LEA having BCC HEA and a large amount of mixed heat at the time of solidification at high temperature occurs, and phase-separated BCC HEA In the course of solidification of the liquid phase, the first phase of BCC HEA having a high melting point has a dendritic structure and Zr-rich BCC LEA second phase constituents having a large melting point and atomic radius difference with the above elements are discharged to the liquid phase region between the dendrites, And the structure is separated by spinodal decomposition by liquid phase and second phase separation behavior of phase-separated M-rich HCP LEA. In particular, when all the elements constituting the BCC HEA are constituted at the equiatomic ratio within an allowable error tolerance of ± 10 at.%, A BCC solid solution base having a high entropy state is constituted to improve the solid solution properties by the increase of entropy .

A method for producing a porous BCC HEA-LEA composite structure according to another embodiment of the present invention is characterized in that at least one element group I and II constituting the BCC HEA each contain at least one element selected from the group consisting of alloying elements A raw material preparation step of preparing an element of M having a large positive (+) mixed thermal relationship with phosphorus Zr and BCC alloy; The raw material is dissolved and cooled to obtain a first phase of BCC HEA material, a second phase separated by melting point and atomic radius difference during BCC HEA solidification, and a third phase of the third phase having a second phase and a spinodal decomposition structure Producing a separated composite material; And removing the third phase to produce a porous article.

In the alloy manufacturing step, since the high melting temperature of the BCC HEA after liquid phase separation between the BCC alloy and the HCP LEA, the first phase, BCC HEA, forms a dendritic structure, and the BCC LEA Phase separation composite material in which the second phase of the material and the third phase phase of the HCP LEA are separated by spinodal decomposition by the second phase separation, and only the third phase is selectively To obtain a composite porous structure of BCC HEA having dendritic and BCC LEA having pores having a spinodal decomposition structure. In this case, the development direction of the resin phase can be controlled by controlling the cooling direction through unidirectional solidification in the alloy manufacturing step, and the internal microstructure such as the size and shape of the dendritic and dendritic regions can be controlled through the subsequent heat treatment of the phase- Can be controlled.

The BCC HEA-LEA composite structure porous body according to another embodiment of the present invention is characterized in that the composite structure is formed by the multistage phase separation behavior of the dendritic region of the BCC HEA material and the BCC LEA region having the spinodal decomposition pore structure.

The BCC HEA-LEA composite structure porous body having the spinodal decomposition pore structure of the present invention has a structure in which pores are distributed within the complex structure of HEA and LEA, and the characteristics of the HEA and the composite structural material having a unique microstructure, The unique physical properties are exhibited by the addition of the properties of the pore structure by the pore structure with the moon structure.

The composite structure porous body is composed of a first phase of a BCC HEA material in a resin phase and a second phase of a BCC LEA material having a large melting point and an atomic radius difference with those of the BCC HEA material, And the third phase formed by separating the BCC LEA and the spinodal decomposing process and having a mixed heat relationship. The third phase may be prepared by removing the third phase, and the inner phase Or may be controlled.

The porosity is a very important factor for determining the properties of the porous article. The composite structure porous article of the present invention is produced by firstly forming the three-phase separated composite material and then selectively removing the third phase through an electrochemical de- The internal porosity can be controlled by adjusting the fraction.

Further, by removing the third phase from the three-phase separated composite material in which the first phase is a dendritic structure, and the second phase and the three phases have a spinodal decomposition structure in the dendritic region, the pore structure of the porous body is uniquely separated Structure.

The multiphase phase separation of the three-phase separated composite material of the present invention constituted as described above is characterized in that the first phase of the BCC HEA material and the solute released to the dendritic region during solidification due to the difference in melting point and radius between the first phase constituent elements The third phase of the HCP LEA material of the M-rich composition having the structure separated by the spinodal decomposition by the second phase phase and the second phase phase of the finally released second phase phase of the Zr-rich BCC LEA material, By separating and coexisting, it is possible to provide a new composite material exhibiting unique physical properties combining the properties of the HEA material and the polyphase separated LEA material.

In addition, the method for producing the porous BCC HEA-LEA composite structure of the present invention is characterized in that the three-phase separation alloy is produced by the multi-stage separation process and then the BCC HEA first phase and the BCC LEA second phase It is possible to produce a novel composite porous structure having a spinodal decomposition pore structure of a unique type which has not been conventionally produced.

Furthermore, the composite structure porous body of the present invention has a structure in which pores are distributed in the composite material of the HEA material and the LEA material. In addition to the high strength properties of the HEA, the composite structure porous body has unique mechanical properties At the same time as the expression, properties such as high stretching and low thermal conductivity possessed by the porous body structure are added, so that various physical properties can be expressed in a complex manner.

1 is a flow chart schematically illustrating an entire process of the present invention.
FIG. 2 is a table summarizing the mixed heat relationship among the elements constituting the present invention.
3 is a diagram showing the atomic radius and the melting point of each element constituting the present invention.
4 is a diagram schematically showing the multi-step phase separation behavior in which the three-phase separated composite material of the present invention is formed.
FIG. 5 is a graphical representation of (a) a sequential path in which each phase solidifies in the multistage phase separation of the present invention, and (b) schematically shows a microstructure that can be obtained through each step.
6 is a scanning electron microscopic analysis image of the specimen of Example 3 of the present invention.
Fig. 7 shows the results of X-ray diffraction analysis of the three-phase separated composite materials of Examples 1 to 4 of the present invention.
8 shows the results of X-ray diffraction analysis for Examples 3 and 5 of the present invention.
Figure 9 is a schematic showing a schematic diagram of an electrochemical selective decomposition corrosion process of the present invention.
10 shows the results of X-ray diffraction analysis of specimens before and after the composition of the composition of Example 3 of the present invention.
11 is a scanning electron micrograph and an EDS (Energy Dispersive Spectroscope) analysis result of the specimen before and after the de-constituting corrosion process of the composition of Example 3 of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the accompanying drawings, embodiments of the present invention will be described in detail.

1 is a flowchart schematically illustrating an entire process for obtaining a BCC HEA-LEA composite structure porous body having a spinodal decomposition pore structure by the multi-stage phase separation behavior of the present invention. In the present invention, an alloy composition capable of multi-phase phase separation is designed to produce a three-phase separated composite material, and a third phase having a spinodal decomposition structure is selectively removed through decarboxylation, thereby forming a composite having a unique spinodal decomposition pore structure To prepare a structural porous body.

3 phases  Separation Composite Design

The present invention relates to a process for producing a solid solution comprising a first phase of a BCC HEA material in which constituent elements of three or more components act as a common solvent through solubility gap control formed in a multicomponent alloy and a first phase of a BCC HEA material constituting a solid solution, Phase phase separation by a large positive (+) mixing relationship with the second phase and BCC alloy elements formed by emission of a large melting point and a radial difference, and a third phase having a final spinodal decomposition structure is separated and coexisted. It is about the material.

First, Ti, V, Cr, Nb, Mo, Hf, Ta and W were selected as the elements constituting the BCC HEA to form the first phase. At this time, in order to prevent the first phase of BCC HEA and the HCP LEA from forming a uniform imbricated composition due to a large density difference and to exhibit an extreme layered structure, Elements of Ti, V and Cr are classified into element group I and elements Nb, Mo, Hf, Ta and W having an atomic mass larger than Y are classified into element group II, Alloyed.

Next, Zr is an alloy element which occupies more than 50 at.% Of the second phase, and Y, La, Ce, Nd, Gd , Tb, Dy, Ho and Er were selected.

2 is a table summarizing the mixed heat relationship of the elements constituting the present invention. The mixing enthalpy difference (ΔH _mix ) between Ti, V, Cr, Nb, Mo, Ta and W and Zr constituting the first and second phases of BCC HEA and LEA is within ± 10 kJ / mole of atoms And the lanthanide elements including Y and La and Er serving as the main elements of the third phase are mixed with a large amount of the elements most than +10 kJ / mole of atoms Heat relationship.

이라는 물리량 (

) 에 의해 평가되며, 이 값이 1.1 보다 큰 경우 안정한 고용체 상을 이루는 것으로 알려져 있다. 즉 아래의 표 1 에 제시된 것과 같이 Zr이 포함되는 경우

이 1.1 보다 작은 값을 나타내어 다른 첨가 원소와 응고 시에 하이엔트로피 고용체를 구성하기 어려운 것을 확인할 수 있으며, 이를 통해 BCC HEA 제 1상의 응고 시에 Zr-rich BCC LEA 용질이 수지상간 액상 영역으로 방출될 것임을 알 수 있다.FIG. 3 shows the melting point and atomic radius of the first and second phase constituent elements, and explains why the BCC LEA is released during the BCC HEA resin phase growth at the time of solidification of the BCC alloy. In the figure, Zr and Hf show a large atomic radius difference with other elements, but Zr has a melting point lower by about 400 K than Hf. In general, the phase stability of the solid solution is

A physical quantity called

). When this value is larger than 1.1, it is known to form a stable solid solution phase. That is, when Zr is included as shown in Table 1 below

Is less than 1.1, indicating that it is difficult to form a high entropy solid at the time of solidification with other additive elements. As a result, the Zr-rich BCC LEA solute is released into the dendritic liquid phase region during the solidification of the first phase of BCC HEA .

Ternary alloy Quaternary alloy When Zr is included 0.795 0.824 When Hf is included 2.095 1.143

4 schematically illustrates the process of separating each phase according to the above conditions. As can be seen in the figure, the first phase, BCC HEA and the second phase, Zr-rich BCC LEA, are separated during solidification due to their large melting point and difference in atomic radius. The total BCC alloy and the amount of +10 kJ / mole Rich HCP LEA, which is a third phase having a mixed column of (+), can have a spinodal decomposition structure by first phase separation with a BCC alloy by a mixed thermal relation and then by a second phase and a second phase separation Able to know.

3 phases  Manufacture of Separated Composites

The alloying elements of BCC HEA, BCC LEA and HCP LEA derived through the design process were alloyed to produce a three - phase separated composite material by the arc melting method. Since the arc melting method can realize a high temperature through the arc plasma, it is selected because it can rapidly produce a homogeneous solid solution in a bulk form and can minimize impurities such as oxides and pores. In addition to the above-mentioned arc melting method, it is possible to manufacture by the commercial casting process by utilizing the induction casting method having stirring effect by the electromagnetic field during melting and the resistance heating method capable of precise temperature control. In addition to this, not only the commercial casting method capable of dissolving the raw material high-melting point metal but also the raw material is made into powder and the like, and the powdery metallurgy method is used for spark plasma sintering or hot isostatic pressing, And sintering at a high pressure. In case of the sintering method, more precise microstructure control and manufacturing of parts having a desired shape are easy.

Table 2 summarizes the compositions of Examples and Comparative Examples according to the present invention, and shows the crystal structures and microstructure forms of phases appearing when solidifying each composition. In this embodiment, the three-phase separation phenomenon was confirmed by changing the number of alloy elements constituting the first phase, and a representative Y was selected as an element constituting the third phase.

Furtherance Crystal structure Microstructural form Example 1 (TiNb-Zr) ₉₀ Y ₁₀ 3 phases
( BCC HEA + BCC LEA + HCP LEA) Composite structure between dendritic and spinodal decomposition dendrites Example 2 (TiNbV-Zr) ₉₀ Y ₁₀ 3 phases
( BCC HEA + BCC LEA + HCP LEA) Composite structure between dendritic and spinodal decomposition dendrites Example 3 (TiNbVMo-Zr) ₉₀ Y ₁₀ 3 phases
( BCC HEA + BCC LEA + HCP LEA) Composite structure between dendritic and spinodal decomposition dendrites Example 4 (TiNbVMoCr-Zr) ₉₀ Y ₁₀ 3 phases
( BCC HEA + BCC LEA + HCP LEA) Composite structure between dendritic and spinodal decomposition dendrites Example 5 (TiNbVMo-Zr) ₆₀ Y ₄₀ 3 phases
( BCC HEA + BCC LEA + HCP LEA) Composite structure between dendritic and spinodal decomposition dendrites Example 6 (TiNbVMoCr-Zr) ₆₀ Y ₄₀ 3 phases
( BCC HEA + BCC LEA + HCP LEA) Composite structure between dendritic and spinodal decomposition dendrites Comparative Example 1 VNbMoTaW 1 phase (BCC) BCC single solid solution Comparative Example 2 NbMoHfTaW 1 phase (BCC) BCC single solid solution Comparative Example 3 NbMoY 2 phases
( BCC HEA + HCP LEA) Layered
Solidified as a separate alloy Comparative Example 4 NbMoY 2 phases
( BCC HEA + HCP LEA) Layered
Solidified as a separate alloy Comparative Example 5 TiNbVY 2 phases
( BCC HEA + HCP LEA) Dendritic-dendritic liver
Two phase separation alloy Comparative Example 6 TiNbVMoY 2 phases
( BCC HEA + HCP LEA) Dendritic-dendritic liver
Two phase separation alloy Comparative Example 7 TiNbVMoCrY 2 phases
( BCC HEA + HCP LEA) Dendritic-dendritic liver
Two phase separation alloy

FIG. 5 is a schematic view of (a) the solidification path of each separated phase of the three-phase separated composite material of the present invention and (b) the microstructure change during the solidification process. As can be seen in the drawings, the alloys of the present invention exist in a single liquid state at a high temperature, and separation of two liquid phases occurs while passing through the solubility gap of BA and HCP LEA. In the first resin phase solidification of the high melting point BCC HEA, Zr is released into the HCP LEA liquid phase and passes through the solubility gap between the Zr-rich BCC LEA and the Y-rich HCP LEA and forms a dendritic region through the spinodal decomposition behavior.

6 is a scanning electron microscope (SEM) image showing the microstructure of the sample of Example 3 produced through the process of FIG. In this figure, the decomposition structure of BCC HEA formed in the dendritic phase and the spinodal decomposition structure of the BCC LEA and HCP LEA obtained in the dendritic region can be confirmed.

7 (a) - (d) are X-ray diffraction analysis results of Examples 1 to 4 of the present invention. Even if the number of elements constituting the first phase of the BCC HEA material is changed to 2 to 5, , It was confirmed that a three-phase separated composite structure with a spinodal decomposition structure can be obtained in the dendritic region.

Fig. 8 is a result of X-ray diffraction analysis of Example 3 and Example 5 of the present invention. Even if the fraction of Y is increased up to 40 at.%, A three-phase separated complex structure having a spinodal decomposition structure is maintained in the dendritic region .

From the above X-ray diffraction analysis results, regardless of the number of elements selected in each element group constituting BA, (BA) _{100- x} Y _x (BCC HEA, BCC LEA, and HCP LEA) in an alloy composition that can be represented by the following formula (where 0.1≤x≤40 at%).

Further, the three-phase separating alloy of the present invention comprises a first phase of a BCC HEA material having a dendritic structure and a second phase and a third phase of BCC LEA and HCP LEA having a spinodal decomposition structure in a dendritic region, And the unique microstructure of the microcapsules are mixed and the respective properties are expressed, thereby exhibiting unique physical properties.

Spinoidal  With decomposition pore structure BCC HEA -LEA composite structure porous article

Another embodiment of the present invention is a BCC HEA-LEA composite structure porous body having a spinodal decomposition pore structure, wherein a resinous BCC HEA and a BCC LEA having a spinodal decomposition structure have a complex structure. Although the porous metal porous body has a low density due to pores therein, the metal porous body is used for electrode materials and heat storage materials by using a large surface area, and attempts to utilize the heat insulating characteristics due to the pores formed therein have been continued. It is also possible to produce artificial composites which are difficult to form naturally by filling other materials into the pores.

The BCC HEA-LEA composite structure porous body of the present invention is manufactured using the three-phase separated composite material prepared as described above, and the manufacturing method thereof includes a raw material preparation step of preparing a metal element for producing a three- An alloy manufacturing step for manufacturing the material, and a step for selectively removing the third phase from the three-phase separated composite material.

The raw material preparing step and the manufacturing step are the same as those described in the above-mentioned production of the three-phase separated composite material, and thus a detailed description thereof will be omitted.

The selective removal step of the third phase selectively removes only the third phase of the HCP LEA composed of main elements of 50 at.% Or more, leaving only the complex structure of BCC HEA and BCC LEA, and the spinodal decomposition structure type To a pore, thereby providing a porous article having a unique pore structure in the form of a spinodal decomposition structure.

Figure 9 is a schematic showing a schematic diagram of an electrochemical selective decomposition corrosion process of the present invention. The two-phase separated alloy produced as shown in FIG. 9 was immersed in a dilute nitric acid solution to promote the galvanic cell reaction, and the third phase corresponding to the negative electrode was dissolved by the galvanic potential difference. At this time, it is possible to completely remove the third phase, and it is also possible to partially leave the third phase for controlling the porosity. In addition, the porosity can be controlled by changing the concentration or kind of the corrosion solution used in the de-component corrosion process, or by changing the process conditions such as the process time and temperature.

Fig. 10 shows the results of X-ray diffraction analysis of the specimen before and after the decontamination corrosion of Example 3 composition. Fig. As shown in FIG. 6, the three-phase structure of BCC HEA, BCC LEA and HCP LEA is formed in the casting structure of Example 3 of the present invention, whereas after the decolorization, the Y-rich HCP LEA phase is selectively And it can be confirmed that only the composite structure of the BCC alloys remains.

FIG. 11 is a schematic diagram showing a scanning electron microscope photograph and an EDS (Energy Dispersive Spectroscope) analysis result of the specimen before and after the decontamination corrosion of the composition of Example 3 of the present invention. FIG. It can be seen from this selective dissolution that a complex structure porous structure of BCC HEA having a dendritic branch form and BCC LEA having a spinodal decomposition pore structure is formed, and in the case of BCC LEA, an alloy system in which Zr is a major element of 50 at.% Or more Can be confirmed.

While the present invention has been particularly shown and described with reference to preferred embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Those skilled in the art will understand. Therefore, the scope of protection of the present invention should be construed not only in the specific embodiments but also in the scope of claims, and all technical ideas within the scope of the same shall be construed as being included in the scope of the present invention.

Claims (14)

One or more metal elements are selected from element group I consisting of Ti, V and Cr, element group II consisting of Nb, Mo, Hf, Ta and W, and element group III consisting of Zr,
Y or at least one metal element (M) selected from the group consisting of lanthanide elements such as La, Ce, Nd, Gd, Tb, Dy, Ho and Er,
A first phase of BCC HEA material;
A second phase which is a BCC LEA material having Zr as a main element; And
And a third phase of HCP LEA having M as a main element.
All the elements constituting the first phase BCC HEA are composed of the same atomic fraction within the tolerance of ± 10 at.%,
(BA) constituting the BCC alloy of the first and second phases and M acting as the main element of the third phase are represented by composition ratios of 100-x Mx (where 0.1? X? 40 at.%) Wherein the three-phase separated composite material is a three-phase separated composite material.
delete delete delete One or more metal elements are selected from element group I consisting of Ti, V and Cr, element group II consisting of Nb, Mo, Hf, Ta and W, and element group III consisting of Zr,
Y or at least one metal element (M) selected from the group consisting of lanthanide elements such as La, Ce, Nd, Gd, Tb, Dy, Ho and Er, Phase BCC LEA and a third phase HCP LEA;
Phase composite material between the first phase BCC HEA, the second phase BCC LEA and the third phase HCP LEA; And
And removing the HCP LEA composition selectively to produce a porous body. The method of producing a porous BCC HEA-LEA composite structure having a spinodal pore structure.
The method of claim 5,
Wherein the step of designing the three-phase separated composite material comprises the steps of: designing the BCC LEA, which is the second phase of Zr-rich, to be released in a liquid phase upon solidification of the first phase to form a composite material, the BCC having a spinodal pore structure HEA-LEA composite structure porous article.
The method of claim 5,
Wherein the step of designing the three-phase separated composite material comprises the step of separating the M phase acting as the main phase of the third phase by BCC LEA and spinodal decomposition, wherein the BCC HEA-LEA composite structure having a spinodal pore structure A method for producing a porous article.
The method of claim 5,
Wherein the step of fabricating the three-phase separated composite material is performed by a multi-stage phase separation method, wherein the BCC HEA-LEA composite structure porous body having a spinodal pore structure is produced.

The method of claim 5,
Wherein the step of preparing the three-phase separated composite material comprises the steps of: preparing a BCC HEA-LEA composite structure porous body having a spinodal pore structure, wherein the direction of development of the resin phase of the first phase BCC HEA is controlled by adjusting a cooling direction .
The method of claim 5,
A method for producing a porous BCC HEA-LEA composite structure having a spinodal pore structure, characterized in that, in the step of selectively removing the third phase, nitric acid is used for an electrochemical deoxidation process.
The method of claim 5,
Wherein the inner phase porosity is controlled by controlling the time of decolorization in the step of selectively removing the third phase. The method of producing a porous BCC HEA-LEA composite structure having a spinodal pore structure.
One or more metal elements are selected from element group I consisting of Ti, V and Cr, element group II consisting of Nb, Mo, Hf, Ta and W, and element group III consisting of Zr,
Y or at least one metal element (M) selected from the group consisting of lanthanide elements such as La, Ce, Nd, Gd, Tb, Dy, Ho and Er,
A first phase of BCC HEA material;
A second phase which is a BCC LEA material having Zr as a main element; And
And a third phase of HCP LEA having M as a main element.
All the elements constituting the first phase BCC HEA are composed of the same atomic fraction within the tolerance of ± 10 at.%,
(BA) constituting the BCC alloy of the first and second phases and M acting as the main element of the third phase are represented by composition ratios of 100-x Mx (where 0.1? X? 40 at.%) Wherein the third phase of the three-phase separated composite material is removed through an electrochemical de-etching method.
BCC HEA-LEA and having pores having a spinodal decomposition structure therein. delete delete

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