KR20200042279A - Medium-entropy alloys and Manufacturing method of the same - Google Patents

Abstract

The present invention provides medium-entropy alloy capable of forming precipitates at a base of an FCC structure and securing excellent strength and ductility due to transformation organic plasticity, and a method for manufacturing the same. Introduced is the medium-entropy alloy comprising: 3 to 15 atomic% of Cr; 40 to 60 atomic% of Fe; 5 to 20 atomic% of Co; 5 to 20 atomic% of Ni; and 3 to 15 atomic% of Mo.

Description

Medium-entropy alloys and manufacturing method of the same

The present invention relates to a heavy entropy alloy and its manufacturing method. More specifically, it relates to a Co-Cr-Fe-Ni-Mo-based heavy entropy alloy showing excellent mechanical properties and a method for manufacturing the same.

Various alloys such as steel, aluminum alloys, and titanium alloys based on certain major elements have been developed according to the advancement of industrial technology, but recently, an alloy called a high-entropy alloy is proposed and developed as a new alloy system. have.

Such a high-entropy alloy is a multi-element alloy of 5 or more members, and intermetallic compounds are not formed due to high constitutional entropy despite the mixing of multi-component main elements, and face centered cubic (FCC) or body centered cubic It is a new concept of new material composed of (Body Centered Cubic, BCC).

Typically, alloys are divided into high entropy alloys, medium-entropy alloys (MEAs), and low-entropy alloys (LEAs) according to the compositional entropy (△ Sconf) according to the composition of the alloying element. It is divided into the following conditions.

[Equation 1] △ Sconf (LEAs) ≤ 1.0 · R

[Equation 2] 1.0 · R ≤ △ Sconf (MEAs) ≤ 1.5 · R

[Equation 3] 1.6 · R ≤ △ Sconf (HEAs)

(R: Gas constant)

Among the high-entropy alloys designed through the above definition, the FCC-based high-entropy alloy exhibits excellent mechanical properties. In the case of the Fe-Mn-Cr-Co-Ni-based high-entropy alloy, it is seen in existing structural materials due to the expression of mechanical twins between cryogenic strains It has attracted attention as a material that can be applied as a structural material in extreme environments by having excellent cryogenic properties and high fracture toughness.

However, unlike the cryogenic temperature at room temperature, the formation of mechanical twins is not active, and thus exhibits very low mechanical properties compared to commercial structural materials. In addition, considering the yield strength, which is one of the important factors in the application of structural materials, it also shows a low yield strength, which is the limit of FCC-based metals, as a high-entropy alloy, which limits the scope of application as a structural material and cannot replace existing commercial materials. There are limits.

On the other hand, in the past, development of high-entropy alloys made of the same atom composition has been actively conducted, but in recent years, the type of high-entropy alloys with the same atomic composition showing excellent properties is very limited, and it is argued that the high composition entropy is not a requirement to show excellent properties Became.

Accordingly, various heavy entropy alloys exhibiting excellent properties of corrosion resistance, high strength, and high ductility have been developed, and in order to expand the application area of the heavy entropy alloys, development of heavy entropy alloys having various characteristics is required.

In addition, in order to apply the medium-entropy alloy as a structural material in various fields, it is essential to increase the tensile strength while maintaining the characteristics exhibited by the existing high-entropy alloy and secure excellent mechanical properties at room temperature.

The present invention provides a medium-entropy alloy capable of forming precipitates at the base of the FCC structure and securing excellent strength and ductility due to transformation organic plasticity, and a method for manufacturing the same.

Heavy entropy alloy according to an embodiment of the present invention Cr: 3 to 15 atomic%, Fe: 40 to 60 atomic%, Co: 5 to 20 atomic%, Ni: 5 to 20 atomic% and Mo: 3 to 15 atomic %.

The content ratio of Cr to Cr content (Cr / Co) may be 1 or less.

It may be made of a single-phase face-centered cubic structure (FCC).

A microphase may be formed in the matrix tissue formed by the face-centered cubic structure (FCC).

The average grain size may be 4 to 8 μm.

During plastic deformation, a deformed organic phase transformation may occur.

The tensile strength is 500MPa or more, and the elongation may be 38% or more.

The method for preparing a heavy entropy alloy according to an embodiment of the present invention is Cr: 3 to 15 atomic%, Fe: 40 to 60 atomic%, Co: 5 to 20 atomic%, Ni: 5 to 20 atomic%, and Mo: 3 to Preparing an ingot comprising 15 atomic percent; Homogenizing heat treatment of the ingot; Cold-rolling the heat-treated ingot to produce a plate material; And annealing the plate material.

After the homogenizing heat treatment of the ingot, the step of polishing the surface of the heat treated ingot; may further include.

In the step of homogenizing heat treatment of the ingot, the heat treatment temperature may be 1100 to 1300 ° C.

In the step of manufacturing the sheet material by cold rolling the ingot, it may be cold rolled with a reduction ratio of 50 to 80%.

In the step of annealing the plate material, the annealing temperature may be 800 to 1250 ° C.

In the step of annealing the plate material, the annealing time may be 10 to 100 minutes.

The heavy entropy alloy according to an embodiment of the present invention induces a precipitation strengthening effect by formation of precipitates, a grain refinement effect by suppressing grain boundary growth due to precipitate formation, and a strengthening effect by strain phase transformation, resulting in a high-entropy alloy of the same fraction. In comparison, it is possible to provide an entropy alloy having excellent mechanical properties.

Figure 1 shows the equilibrium phase change according to the molar fraction and temperature of Co and Cr remaining in the alloy containing 50 atomic% Fe, 10 atomic% Ni and 5% atomic Mo.
FIG. 2 shows phase equilibrium information according to the molar fraction and temperature of Co and Ni remaining in an alloy containing 55 atomic% Fe, 12.5 atomic% Cr, and 5% atomic Mo, and 55 atomic% Fe, 12.5 It shows the phase equilibrium information according to the molar fraction of Co and Ni and the temperature of the remainder in the alloy containing atomic% Cr and 7.5% atomic Mo.
3 is an X-ray diffraction analysis result of a medium entropy alloy plate prepared according to specimens 1 to 4 of Example 1 of the present invention and specimens 1 to 4 of Example 2.
4 is a photograph of EBSD image quality (IQ) map for specimen 2 of Example 2 of the present invention.
Figure 5 is a graph showing the change in the average grain size in the case of annealing by varying the temperature conditions for specimens 1 to 4 and Comparative Examples 1 to 4 of Example 2 of the present invention.
6 is a graph showing the room temperature tensile properties of Examples 1 and 2 of the present invention.
7 is a graph showing the room temperature tensile properties of Example 3, Example 4 and Comparative Example 1 of the present invention.
8 is a result of neutron diffraction analysis before and after modification of Example 3 of the present invention.

Terms such as first, second and third are used to describe various parts, components, regions, layers and / or sections, but are not limited thereto. These terms are only used to distinguish one part, component, region, layer or section from another part, component, region, layer or section. Accordingly, a first portion, component, region, layer or section described below may be referred to as a second portion, component, region, layer or section without departing from the scope of the present invention.

The terminology used herein is only for referring to specific embodiments and is not intended to limit the invention. The singular forms used herein include plural forms unless the phrases clearly indicate the opposite. As used herein, the meaning of “comprising” embodies a particular characteristic, region, integer, step, action, element, and / or component, and the presence or presence of another characteristic, region, integer, step, action, element, and / or component. It does not exclude addition.

When a part is said to be "on" or "on" another part, it may be directly on or on the other part, or another part may be involved therebetween. In contrast, if one part is referred to as being “just above” another part, no other part is interposed therebetween.

Although not defined differently, all terms including technical terms and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which the present invention pertains. Commonly used dictionary-defined terms are additionally interpreted as having meanings consistent with related technical documents and currently disclosed contents, and are not interpreted in an ideal or very formal meaning unless defined.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art to which the present invention pertains can easily practice. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein.

Medium entropy  alloy

Heavy entropy alloy according to an embodiment of the present invention Cr: 3 to 15 atomic%, Fe: 40 to 60 atomic%, Co: 5 to 20 atomic%, Ni: 5 to 20 atomic% and Mo: 3 to 15 atomic %.

Below, the reasons for limiting the content of each component element will be described.

Cr: 3 to 15 atomic%

If chromium (Cr) is less than 3 atomic%, it may adversely affect the physical properties of the alloy, such as corrosion resistance. On the other hand, when it exceeds 15 atomic%, there is a high possibility that the intermediate phase formation and the FCC single phase region are not present. Therefore, Cr is added at 3 to 15 atomic%.

Specifically, by adding 5 to 15 atomic% to form a metastable FCC phase, mechanical properties at room temperature can be further improved.

Fe: 40 to 60 atomic%

When iron (Fe) is less than 40 atomic%, the FCC phase is stabilized, so the effect of improving mechanical properties may not be significant. On the other hand, when it exceeds 60 atomic%, the BCC phase is stabilized, so the effect of improving the mechanical properties may not be large. Therefore, Fe is added at 40 to 60 atomic%.

Specifically, by adding 48 to 58 atomic% to form a metastable FCC phase, mechanical properties at room temperature can be further improved.

Co: 5 to 20 atomic%

When cobalt (Co) is less than 5 atomic%, the FCC phase is stabilized, so the effect of improving mechanical properties may not be significant. On the other hand, when it exceeds 20 atomic%, the BCC phase is stabilized, and thus the effect of improving the mechanical properties may not be large. Therefore, Co is added at 5 to 20 atomic%.

Ni: 5 to 20 atomic%

When nickel (Ni) is less than 5 atomic%, the BCC phase is stabilized, so the effect of improving mechanical properties may not be significant. On the other hand, when it exceeds 20 atomic%, the FCC phase is stabilized, and the effect of improving mechanical properties may not be as great. Therefore, Ni is added at 5 to 20 atomic%.

Mo: 3 to 15 atomic%

When molybdenum (Mo) is less than 3 atomic%, it may be difficult to obtain a sufficient strengthening effect. On the other hand, when it exceeds 15 atomic%, there is a high possibility that the intermediate phase formation and the FCC single phase region are not present. Therefore, Mo is added at 3 to 15 atomic%.

Specifically, the stability and mechanical properties of the phase may be further improved by adding 5 to 10 atomic%.

The heavy entropy alloy according to an embodiment of the present invention may have a Cr content ratio (Cr / Co) of Co to a content of 1 or less.

It is possible to form the FCC single phase region by satisfying the content ratio of Cr to Cr content (Cr / Co) of 1 or less. In this case, as shown in FIG. 1, the FCC single phase can be maintained in a relatively wide temperature range from the dissolution temperature to about 800 ° C. On the other hand, when the content ratio of Cr to Cr content (Cr / Co) exceeds 1, it may be difficult to form the FCC single phase region by reducing the temperature region maintaining the FCC single phase region.

Figure 1 shows the equilibrium phase change according to the molar fraction and temperature of Co and Cr remaining in the alloy containing 50 atomic% Fe, 10 atomic% Ni and 5% atomic Mo.

Through this, the FCC single phase is maintained from the melting temperature to 800 ° C in the region where the molar fraction of Cr is 15% or less, and the FCC + μ phase two-phase equilibrium region exists below 800 ° C, and the molar fraction of Cr is 15% or more. It can be seen from below that all of the FCC + σ two-phase equilibrium regions exist below the dissolution temperature.

FIG. 2 shows phase equilibrium information according to the molar fraction and temperature of Co and Ni remaining in an alloy containing 55 atomic% Fe, 12.5 atomic% Cr, and 5% atomic Mo, and 55 atomic% Fe, 12.5 It shows the phase equilibrium information according to the molar fraction of Co and Ni and the temperature of the remainder in the alloy containing atomic% Cr and 7.5% atomic Mo.

Through this, all alloys having a ternary system or lower containing 55 atomic% Fe, 12.5 atomic% Cr, 7.5 atomic% or less Mo, 30 atomic% Ni, and 30 atomic% Co are all 900 ° C from the melting temperature, respectively. It can be seen that the FCC single phase is maintained up to 1100 ° C or lower.

The heavy entropy alloy according to an embodiment of the present invention may be formed of a single-phase face-centered cubic structure (FCC), or may be formed in a form in which a μ-phase is formed in a matrix structure formed of a face-centered cubic structure (FCC).

When a μ-phase is formed in a matrix structure formed of a face-centered cubic structure (FCC), the average grain size may be 4 to 8 μm because the growth of grains is suppressed by precipitation of a μ-phase in the grain boundaries of the FCC matrix.

The heavy entropy alloy according to an embodiment of the present invention may undergo a deformation phase transformation during plastic deformation. The tensile strength is 500MPa or more, and the elongation may be 38% or more.

Medium entropy  Alloy manufacturing method

The method for preparing a heavy entropy alloy according to an embodiment of the present invention is Cr: 3 to 15 atomic%, Fe: 40 to 60 atomic%, Co: 5 to 20 atomic%, Ni: 5 to 20 atomic%, and Mo: 3 to It includes a step of manufacturing an ingot containing 15 atomic%, a step of homogenizing heat treatment of the ingot, a step of cold-rolling the heat-treated ingot to produce a plate material, and annealing the plate material.

After the homogenizing heat treatment of the ingot, the step of polishing the surface of the heat treated ingot may be further included.

The reason for limiting the content of each component constituting the ingot is omitted because it overlaps with the description of the heavy entropy alloy.

First, in the step of manufacturing an ingot, each component element having a purity of 99.9% or more is weighed and charged into a crucible, and then heated to a temperature of 1400 to 1800 ° C to dissolve and then ingot can be cast through a mold.

Next, in the step of homogenizing heat treatment of the ingot, heat treatment is performed to homogenize the microstructure of the ingot. At this time, the heat treatment temperature may be 1100 to 1300 ℃. The heat treatment time may be 4 to 8 hours. When the heat treatment temperature is less than 1100 ° C, the homogenization effect of the microstructure may not be sufficient. On the other hand, if it exceeds 1300 ° C, the heat treatment cost may be excessive.

Next, in the step of polishing the surface of the heat-treated ingot, the oxide formed on the surface of the ingot can be removed by grinding the surface of the heat-treated ingot.

Next, in the step of manufacturing the sheet material by cold rolling the ingot, the heat-treated ingot is cold-rolled. At this time, the ingot may be cold rolled so that the reduction ratio is 50 to 80%.

Next, in the step of annealing the plate material, the annealing treatment of the plate material may cause the μ phase to be deposited on the FCC matrix according to the annealing conditions.

The annealing temperature may be 800 to 1250 ° C. Specifically, it may be 900 to 1200 ℃. The annealing time may be 10 to 100 minutes.

In general, as the temperature during annealing increases, the size of the grains grows, but the growth of grains is suppressed by the precipitation of μ phases in the grains, especially in the FCC matrix. Accordingly, excellent yield strength and room temperature mechanical properties may be exhibited due to grain refinement.

Hereinafter, specific examples of the present invention will be described. However, the following examples are only specific examples of the present invention, and the present invention is not limited to the following examples.

Example

(One) Example  And Comparative example  Follow Medium entropy  Preparation of alloy

[Examples] Fe, Co, Ni, Cr, Mo metal having a purity of 99.9% or more was prepared to prepare an ingot having a composition as shown in Table 1 below. After the prepared raw metal was charged to the crucible, it was heated and dissolved at 1550 ° C, and a mold was used to cast a plurality of ingots having a rectangular parallelepiped shape of 150 g in thickness 7.8 mm, width 33 mm, and length 80 mm.

The cast ingot was subjected to a homogenization heat treatment at a temperature of 1250 ° C. for 6 hours, followed by surface grinding to remove oxides formed on the surface of the ingot, and the thickness of the polished ingot became 7 mm. The surface-polished ingot having a thickness of 7 mm was cold rolled to 1.5 mm.

A plurality of alloy plate materials according to Examples 1 to 4 were prepared and annealed under the conditions in Table 2 below.

[Comparative Example] Fe, Mn, Co, Ni, and Cr metals having a purity of 99.9% or more were prepared and prepared to have a mixing ratio as shown in Table 1 below.

Subsequently, a plurality of alloy plate materials according to Comparative Example 1 were prepared through the same process as in Example 1, and annealed under the conditions shown in Table 2 below.

Raw material mixing ratio (atomic%) Fe Co Ni Cr Mo Mn Example 1 55 17.5 10 12.5 5 - Example 2 55 18 7 12.5 7.5 - Example 3 55 19.5 8 12.5 5 - Example 4 55 20 5 12.5 7.5 - Comparative Example 1 20 20 20 20 - 20

Psalter Annealing temperature (℃) Annealing time (minutes) Example 1 (Psalm 1) 900 60 Example 1 (Psalm 2) 1000 60 Example 1 (Psalm 3) 1100 60 Example 1 (Psalm 4) 1200 60 Example 2 (Psalm 1) 900 60 Example 2 (Psalm 2) 1000 60 Example 2 (Psalm 3) 1100 60 Example 2 (Psalm 4) 1200 60 Example 3 (Psalm 1) 800 60 Example 3 (Psalm 2) 850 60 Example 3 (Psalm 3) 900 60 Example 4 (Psalm 1) 900 60 Example 4 (Psalm 2) 1000 60 Example 4 (Psalm 3) 1100 60 Example 4 (Psalm 4) 1200 60 Comparative Example 1 (Psalm 1) 900 60 Comparative Example 1 (Psalm 2) 1000 60 Comparative Example 1 (Psalm 3) 1100 60 Comparative Example 1 (Psalm 4) 1200 60

(2) X-ray diffraction analysis results

FIG. 3 shows the results of X-ray diffraction measurement at room temperature of the alloys of Example 1 (Psalms 1 to 4) and Example 2 (Psalms 1 to 4) subjected to annealing treatment.

X-ray diffraction measurement was performed after polishing in the order of sandpaper 600, 800, and 1200 in order to minimize phase transformation due to deformation during polishing of the specimen, and then electrolytic polishing in 8% perchloric acid.

As a result, as shown in FIG. 3, in the case of Example 1, upon annealing at 900 ° C. or less (Psalm 1), the metastable FCC phase is predominant, and the μ phase is observed as a phase containing a small amount, and the temperature is higher than that. Upon annealing in Essence (Psalms 2-4), it was observed to form a metastable FCC single phase.

On the other hand, in the case of Example 2, when annealing at a temperature of 1100 ° C. or lower (Psalms 1 to 3), a metastable FCC phase is predominant and observed as a phase containing a μ phase, and when annealing at a temperature of 1200 ° C. or higher (Psalm 4) Only the metastable FCC was observed to form a single phase.

That is, as the content of Mo increases, the FCC single-phase reverse region becomes narrower, and as a result, a phase in which a metastable FCC phase and a μ phase coexist in a wide temperature range as in Samples 1 to 3 of Example 2 was formed.

(3) μ phase  Formation and Grain boundary  Size analysis result

4 is a photograph of EBSD image quality (IQ) map for specimen 2 of Example 2.

As shown in FIG. 4, it can be seen that the μ phase is mostly formed in the grain boundary, and a part exists in the grain.

Figure 5 shows the grain size change according to the annealing treatment temperature change through the EBSD analysis of the alloys of the specimens 1 to 4 of Comparative Example 1 and specimens 1 to 4 of Example 2 subjected to annealing treatment.

As can be seen in Figure 5, in Comparative Example 1, the grain size grows as the temperature increases, but in Example 2, at a temperature of 1100 ° C. or lower where the μ phase is present, it is constant at about 6 μm, and there is no μ phase. It can be seen that the grain size grows at a temperature of 1200 ° C. or higher and has a relatively small grain size compared to Comparative Example 1.

That is, it can be seen that the grain growth suppression shown in Example 2 is largely formed in the vicinity of the grain boundary by the addition of Mo, and a μ-phase is formed around the grain boundary, which greatly contributes to the suppression of grain growth between annealing treatments by the Zener pinning effect.

(4) Tensile test result

6, 7, and Table 3 are specimens 1 to 4 of Example 1, specimens 1 to 4 of Example 2, specimens 1 to 3 of Example 3, specimens 1 to 3 of Example 4, and Comparative Example 1, respectively. The results of the room temperature tensile test of specimen 2 of the.

Psalter Yield strength (MPa) Tensile strength (MPa) Elongation (%) Example 1 (Psalm 1) 433 840 61.6 Example 1 (Psalm 2) 301 718 77.5 Example 1 (Psalm 3) 261 673 86.6 Example 1 (Psalm 4) 231 638 87.2 Example 2 (Psalm 1) 711 1096 38.3 Example 2 (Psalm 2) 684 1078 48.1 Example 2 (Psalm 3) 506 933 59.3 Example 2 (Psalm 4) 296 693 63.2 Example 3 (Psalm 1) 1090 1190 46.1 Example 3 (Psalm 2) 651 1077 61.3 Example 3 (Psalm 3) 525 996 71.1 Example 4 (Psalm 1) 880 1372 20.8 Example 4 (Psalm 2) 656 1108 50.1 Example 4 (Psalm 3) 561 979 81.5 Comparative Example 1 (Psalm 2) 194 599 63.2

6, 7 and Table 3, it can be seen that the room temperature tensile property of the heavy entropy alloy prepared according to the embodiment of the present invention varies greatly depending on annealing conditions.

Particularly, in the alloy of Example 2, as shown in FIG. 4 depending on the annealing conditions, a μ phase was formed in the FCC matrix, and yield strength and tensile strength were significantly improved (yield strength: 296 MPa-> 684 MPa, Tensile strength: 693MPa-> 1078MPa) It was confirmed that the elongation was slightly reduced compared to specimen 4 of Example 2 showing FCC single-phase structure.

In addition, when compared with the specimen 2 of Comparative Example 1, which is an FCC-based high-entropy alloy having the same molar fraction as Examples 3 and 4 of the present invention, the yield strength and tensile strength are improved by the precipitation strengthening effect by the μ phase, and at the same time. It was confirmed that the elongation was also slightly increased.

(5) Deformation Phase transformation

FIG. 8 shows the results of neutron diffraction analysis for the expression of strain-induced phase transformation during tensile deformation of the heavy entropy alloy according to Example 4 of the present invention.

As shown in FIG. 8, it is observed that the alloy of Example 4 is mainly composed of the FCC phase that is metastable at the beginning and contains a small amount of the μ phase.

On the other hand, after the tensile strain, the neutron diffraction peak of the BCC phase appears stronger than the diffraction peak of the FCC phase due to the strain organic phase transformation to the BCC phase between the metastable FCC phase deformations, which means that the phase fraction of the BCC phase after deformation becomes larger.

The present invention is not limited to the above embodiments and / or embodiments, but may be manufactured in various different forms, and those skilled in the art to which the present invention pertains may change the technical spirit or essential features of the present invention. It will be understood that it may be practiced in other specific forms without. Therefore, it should be understood that the above-described embodiments and / or embodiments are illustrative in all respects and not restrictive.

Claims (13)

Heavy entropy alloy comprising Cr: 3-15 atomic%, Fe: 40-60 atomic%, Co: 5-20 atomic%, Ni: 5-20 atomic% and Mo: 3-15 atomic%. According to claim 1,
The content ratio of Cr to Cr content (Cr / Co) is 1 or less heavy entropy alloy. According to claim 1,
Medium entropy alloy consisting of single-phase face-centered cubic structures (FCC). According to claim 1,
Medium entropy alloy with μ-phase formed in matrix structure formed by face-centered cubic structure (FCC). According to claim 4,
A medium entropy alloy having an average grain size of 4 to 8 µm. According to claim 1,
A medium entropy alloy in which plastic phase transformation occurs during plastic deformation. According to claim 1,
A medium-entropy alloy with a tensile strength of 500 MPa or more and an elongation of 38% or more. Preparing an ingot comprising Cr: 3-15 atomic%, Fe: 40-60 atomic%, Co: 5-20 atomic%, Ni: 5-20 atomic% and Mo: 3-15 atomic%;
Homogenizing heat treatment of the ingot;
Cold-rolling the heat-treated ingot to produce a plate material; And
Annealing the plate material; The method of manufacturing a medium entropy alloy comprising a. The method of claim 8,
After the step of homogenizing heat treatment of the ingot,
Polishing the surface of the heat-treated ingot; Medium entropy alloy manufacturing method further comprising. The method of claim 8,
In the step of homogenizing heat treatment of the ingot,
The heat treatment temperature is 1100 to 1300 ℃ medium entropy alloy manufacturing method. The method of claim 8,
In the step of manufacturing a sheet material by cold rolling the ingot,
A method of manufacturing a heavy entropy alloy that is cold rolled at a rolling reduction rate of 50 to 80%. The method of claim 8,
In the step of annealing the plate material,
A method for manufacturing a medium entropy alloy having an annealing temperature of 800 to 1250 ° C. The method of claim 8,
In the step of annealing the plate material,
A method for manufacturing a medium entropy alloy having an annealing time of 10 to 100 minutes.

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