KR101927611B1 - High- strength and heat-resisting high entropy alloy matrix composites and method of manufacturing the same - Google Patents

Abstract

The present invention relates to a high-strength super-heat-resistant high entropy alloy matrix composite material and a method of manufacturing the same. More particularly, And Al; a base element selected from the group consisting of Al and Al; And a sintering insulator forming alloy element, and a method of manufacturing the same.
INDUSTRIAL APPLICABILITY The present invention can improve the strength and high-temperature stability of a high entropy alloy matrix composite material and improve the yield.

Description

TECHNICAL FIELD [0001] The present invention relates to a high-strength super-heat-resistant high entropy alloy matrix composite material and a method of manufacturing the same. BACKGROUND ART [0002]

TECHNICAL FIELD The present invention relates to a high strength super heat resistant high entropy alloy matrix composite material and a manufacturing method thereof.

The development of existing alloy materials is aimed at improving the properties such as strength, toughness, heat resistance and corrosion resistance by adding trace elements based on major metals such as Ti and Ni. At present, development of alloy materials by adding trace elements has reached the limit.

Recently, the entropy alloys have been actively studied. They are composed of 4 to 5 or more metal elements mixed at a constant element ratio, and have high mechanical entropy, excellent lattice warping due to difference in size of elements, Is being reported.

The CoCrFeMnNi entropy alloy reported in Science magazine in 2014 exhibits fracture toughness of 200 MPa · m ^0.5 , which is close to three times that of titanium alloys. It is a next-generation extreme environment material that can replace existing structural alloys. It is attracting attention.

In order to further increase the applicability of high entropy alloys, research on improvement of mechanical properties through addition of reinforcement materials is required. For this purpose, researches are being conducted on composite materials using oxidized materials and carbonized materials used as reinforcements in existing metal bases. In order to uniformly disperse the reinforcement material and refine the crystal structure, research results using powder metallurgy process have been reported. In powder metallurgy process, high energy milling process including oil mill is mainly used.

In the case of high energy milling process using FCC - based entropy alloy with high ductility, cold welding occurs on balls and containers during milling process, resulting in low yield of powder and contamination by balls.

In the case of a composite entropy alloy to which a reinforcing material is added, the reinforcing material tends to be a reaction point causing cold-pressing, and serious yield deterioration is caused by cold-pressing. A new technique is needed to reduce the cold pressing phenomenon of the composite high entropy alloy using the powder metallurgy process.

Disclosure of the Invention The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a high entropy alloy matrix composite material capable of improving the heat resistance and mechanical properties of an alloy and lowering the cold- will be.

The problems to be solved by the present invention are not limited to the above-mentioned problems, and other matters not mentioned can be clearly understood by those skilled in the art from the following description.

One aspect of the present invention is to provide a method of manufacturing a base material comprising at least four base elements selected from the group consisting of Co, Cr, Fe, Ni, Mn, Cu, Mo, V, Nb, Ta, Ti, Zr, W, Si, Hf, ; And sintering additive element; To a high entropy alloy matrix composite material.

According to an embodiment of the present invention, the high entropy alloy matrix composite material further comprises a reinforcement material, wherein the reinforcement material is at least one of Al, Si, Ti, Zr, Ta, Mg, Be, Ba, Zn, Metal silicide, metal carbide, metal nitride and metal boride containing at least one of Sn, W, Hf, V, Nb, Ta, Mo, W, Ta, Or more species.

According to an embodiment of the present invention, the reinforcing material may be contained in an amount of 0.01 to 50 volume% with respect to the high entropy alloy matrix composite material.

According to an embodiment of the present invention, the value of the VEC (valence electron concentration) may be 7 or less.

According to an embodiment of the present invention, the sintering filler metal forming alloy element is different from the base element and includes at least one element selected from the group consisting of Al, Cr, Mn, Mo, Nb, Ta, Ti, . ≪ / RTI >

According to an embodiment of the present invention, the sintered body forming alloy element may be contained in an amount of 0.01 mol% to 90 mol% with respect to the high entropy alloy matrix composite material.

According to an embodiment of the present invention, the VEC (valence electron concentration) of the high entropy alloy matrix composite material may be 10 or less.

According to an embodiment of the present invention, the high entropy alloy matrix composite material further includes a precipitate phase, and the precipitate phase is at least one of Co, Cr, Fe, Ni, Mn, Cu, Mo, V, Nb, A metal oxide including at least one of Ti, Zr, Ta, Mg, Be, Ba, Zn, Cr, Y, Sn, W, Hf, V, Nb, Ta, Mo, W, Ta, La, , Metal silicides, metal carbides, metal nitrides, metal borides and intermetallic compounds; And at least one selected from the group consisting of

According to an embodiment of the present invention, the precipitated phase may be at least one selected from the group consisting of Ni ₃ Nb, TiC, MoC, CrC, Cr ₂₃ C ₆ , Mo ₂₃ C ₆ , W ₂₃ C ₆ , Co ₂₃ C ₆ , Fe ₂₃ C ₆ , Mo _{6 c, W 6 c, Co 6} c, Ni 6 c, Ni 3 Al, Ni 3 Ti, TiAl and Cr _a Mo _b Ni _c comprises at least one selected from the group consisting of (a, b, and c is a rational number) can do.

In another aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: at least four base elements selected from the group consisting of Co, Cr, Fe, Ni, Mn, Cu, Mo, V, Nb, Ta, Ti, Zr, W, Si, Hf and Al; And a sintering intermetallization forming alloy element; Forming a mechanical alloying powder that mechanically alloys the mixed powder; And high-temperature sintering the mechanical alloying powder; Wherein the mechanical alloying powder forming step is a method of manufacturing a high entropy alloy matrix composite material, wherein the sintering intermetallization forming alloy element bonds with at least a part of the base element.

According to one embodiment of the present invention, the step of forming the mechanical alloying powder is performed using a high energy ball milling apparatus, and a high entropy alloy matrix composite material can be obtained at a yield of 50% or more.

According to an embodiment of the present invention, the step of preparing the mixed powder may further comprise a reinforcement material, a precipitate forming element, or both.

According to an embodiment of the present invention, there is provided a method for producing a metal alloy, comprising the steps of preparing the mixed powder or forming a mechanical alloying powder, Wherein the precipitation phase forming element is at least one element selected from the group consisting of Co, Cr, Fe, Ni, Mn, Cu, Mo, V, Nb, Al, Si, Ti, Zr, Ta, Mg, And at least one selected from the group consisting of Y, Sn, W, Hf, V, Nb, Ta, Mo, W, Ta, La,

According to an embodiment of the present invention, the method may further include a step of subjecting the mechanical alloying powder to high temperature sintering followed by heat treatment at 300 ° C to 1500 ° C to form a precipitate phase.

According to an embodiment of the present invention, the high-temperature sintering of the mechanical alloying powder may be performed at a temperature of 50% to 99% of the melting point of the mechanical alloying powder.

The present invention relates to a high entropy alloy base compound material having improved mechanical properties by adding a body-centered cubic (BCC) -forming alloy element to a high entropy alloy base to lower the occurrence of cold- .

1 is a flow chart illustrating a method of manufacturing a high entropy alloy matrix composite material according to an embodiment of the present invention.
FIG. 2 shows the yields of powders of the entropy alloy base composite material prepared according to Examples 1 to 3 and Comparative Examples 1 and 2 of the present invention.
3 is an X-ray diffraction (XRD) graph of a hyper-entropy alloy matrix composite material produced according to Examples 1 to 3 of the present invention.
4 is a scanning electron microscope (SEM) image of a high entropy alloy matrix composite fabricated according to Example 1 and Example 2 of the present invention.
5 is a graph showing the hardness of the entropy alloy base composite material produced according to Examples 1 to 3 and Comparative Examples 1 and 2 of the present invention.
FIG. 6 is a graph showing the compressive strength of a high entropy alloy matrix composite material manufactured according to Example 1 of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. Also, terminologies used herein are terms used to properly represent preferred embodiments of the present invention, which may vary depending on the user, intent of the operator, or custom in the field to which the present invention belongs. Therefore, the definitions of these terms should be based on the contents throughout this specification. Like reference symbols in the drawings denote like elements.

' 상 및 산화물, 탄화물, 질화물, 붕화물 및 규화물 형성을 비롯한 석출상 형성에 의해서 합금의 기계적 물성과 고온 안정성을 동시에 향상시킬 수 있다. The present invention relates to a high entropy alloy matrix composite material, wherein the high entropy alloy matrix composite material of the present invention according to an embodiment of the present invention has a body centered cubic (FCC) (BCC) forming alloying element is added to increase the brittleness of the powder by a small amount to prevent the cold pressing phenomenon and to improve the yield of the alloy powder in the mechanical alloying process. Also

The mechanical properties and high temperature stability of the alloy can be improved at the same time by forming a precipitate phase including phases and oxides, carbides, nitrides, borides and silicides.

According to an embodiment of the present invention, the high entropy alloy matrix composite material includes a base element; And a sintering intermetallization forming alloy element, and may further comprise a reinforcement material and / or a precipitate phase.

According to an embodiment of the present invention, the base element forms a base high entropy alloy of the high entropy alloy matrix composite material, and is preferably an element forming an alloy of a face centered cubic structure (FCC). For example, the base element can be used without limitation as long as it is an element that forms a surface-to-be-coupled structure. For example, the base element may be any one of Co, Cr, Fe, Ni, Mn, Cu, Mo, And at least one selected from the group consisting of Ta, Ti, Zr, W, Si, Hf and Al and preferably at least one selected from the group consisting of CoCrFeNi, CoCrFeMn, CoCrFeCu, CoCrFeMo and CoCrFeV, CoCrFeNb, CuCrFeNi and CoCrCuNi Quaternary alloys; A quaternary alloy of any one of CoCrFeNiMn, CoCrFeNiCu, CoCrFeNiMn, CoCrFeNiMo, CoCrFeNiV, CuCrFeNiMn, CoCrCuFeNi and CoCrFeNiNb; And a hexagonal system alloy of any one of CoCrFeNiMnMo, CoCrFeNiMnCu, CoCrFeNiMnV and CoCrFeNiMnNb; Lt; / RTI >

For example, the base elements may be included in an amount of 5 mol% to 35 mol% with respect to the base high entropy alloy, respectively.

For example, an alloy base, for example, an alloy having an average VEC (valence electron concentration) of 8 or more may be used as the FCC phase alloy It is possible to prevent the cold-press-contact in the mechanical alloying process and to improve the yield of the alloy powder remarkably by adding the sintering additive-forming alloying element capable of lowering the alloy average VEC to 8 or less. In addition, it is possible not only to prevent contamination by the balls due to cold pressing, but also to improve the mechanical properties of the alloy.

For example, the shed-insulator-forming alloying element is an element capable of lowering the average VEC of the high-entropy alloy, and preferably has a VEC value of 7 or less; More preferably not more than 6.8; And more preferably at most 5 elements and may include at least one element selected from the group consisting of Al, Cr, Mn, Mo, Nb, Ta, Ti, V and W. The VEC is a value obtained by adding the valence electrons and the number of atoms contained in the d-orbital. In the 2011 Journal of Applied Physics, Guo et al. According to the published articles, the entropy alloy can determine the FCC and BCC phases by VEC of constituent elements.

For example, the sintering filler metal forming alloy element may be added in an amount of 0.01 mol% to 90 mol% with respect to the high entropy alloy matrix composite material; 0.1 mol% to 60 mol%; 0.1 to 30 mol%; 0.1 mol% to 20 mol%; Or from 0.1 mol% to 5 mol%. When the content of the sintering initiator forming alloying element is within the above range, it is possible to provide a metal composite material which is excellent in mechanical properties while preventing cold pressing in the mechanical alloying process .

The reinforcing material may be one selected from the group consisting of Al, Si, Ti, Zr, Ta, Mg, Be, Ba, Zn, Cr, Y, Sn At least one selected from the group consisting of metal oxides, metal silicides, metal carbides, metal nitrides and metal borides including at least one of W, Hf, V, Nb, Ta, Mo, W, Ta, . ≪ / RTI >

For example, the metal oxide may be selected from the group consisting of Al ₂ O ₃ , SiO ₂ , TiO ₂ , ZrO ₂ , Ta ₂ O ₅ , MgO, BeO, BaTiO ₃ , ZnO, BaO, CrO ₂ , Y ₂ O ₃ , SnO ₂ , WO to _2, W ₂ O _3, and WO ₃ may include at least one selected from the group consisting of the metal carbide, SiC, TiC, ZrC, HfC, VC, NbC, TaC, Mo ₂ C and WC It may include at least one selected from the group consisting of the metal nitride, include TiN, ZrN, HfN, VN, NbN, TaN, AlN, AlON, and at least one member selected from the group consisting of Si ₃ N ₄ And the metal boride includes at least one selected from the group consisting of TiB ₂ , ZrB ₂ , HfB ₂ , VB ₂ , NbB ₂ , TaB ₂ , WB ₂ , MoB ₂ , B ₄ C and LaB ₆ .

For example, the reinforcement may be present in an amount ranging from 0.01% by volume to 50% by volume of the high entropy alloy matrix composite material; And preferably from 0.05% by volume to 10% by volume. When the content of the reinforcement is within the above range, the alloy is well dispersed in the base and the strength of the metal composite can be improved.

'상; 및 산화물, 탄화물, 질화물, 붕화물, 규화물 및 금속간화합물로 이루어진 군에서 선택된 1종 이상을 포함할 수 있다. In one embodiment of the present invention, the precipitation phase improves the high-temperature properties of the metal composite material to form a high entropy alloy matrix composite material applicable as a material for high temperature. The precipitated phase may include a base element; Alloying Element for In - situ Filling System; And added precipitate forming elements or materials; And the like. For example, the precipitate phase is formed by at least one selected from the group consisting of

'Prize; And at least one selected from the group consisting of oxides, carbides, nitrides, borides, silicides and intermetallic compounds.

'상은 기지 고엔트로피 합금 내에 분산된 기지원소, 체심입방계 형성 합금 원소 및 석출상 형성 원소에서 선택된 1종 또는 2종 이상의 원소들로 이루어진 결정상이며, 예를 들어, Ni₃Al, Ni₃Ti 및 TiAl 등으로 이루어진 군에서 선택된 1종 이상을 포함할 수 있다. For example,

'Phase is a crystalline phase consisting of one or more elements selected from the base element, the sintering transition element forming alloy and the precipitation forming element dispersed in the matrix and entropy alloy, for example Ni ₃ Al, Ni ₃ Ti and TiAl, and the like.

For example, oxides, carbides, nitrides, borides, silicides and intermetallic compounds in the precipitation phase are preferably selected from the group consisting of Co, Cr, Fe, Ni, Mn, Cu, Mo, V, Nb, Al, Si, Ti, Zr, A metal oxide, a metal silicide, a metal carbide, and a metal oxide including at least one of Ta, Mg, Be, Ba, Zn, Cr, Y, Sn, W, Hf, V, Nb, Ta, Mo, W, , Metal nitrides and metal borides, and intermetallic compounds.

For example, the metal carbide, TiC, MoC, CrC, Cr 23 C 6, Mo 23 C 6, W 23 C 6, Co 23 C 6, Fe 23 C 6, Mo 6 C, W 6 C, Co 6 C, Ni ₆ C, and the like.

For example, the intermetallic compound is a binary or higher intermetallic compound, and M1 _a M2 _b And M1 _a M2 _b M3 _c wherein M1 to M3 are at least one element selected from the group consisting of Co, Cr, Fe, Ni, Mn, Cu, Mo, V, Nb, Al, Si, Ti, Zr, Ta, Mg, Wherein a, b and c are the same or different ratios, and the ratios of the ratios of the ratios of ruthenium, tin, have.). Specifically, M1 _a M2 _b is Ni ₃ Nb, Ni ₃ Al, Ni ₃ Ti, TiAl, and the like, and M1 _a M2 _b M3 _c may be a CrMoNi compound such as Cr _a Mo _b Ni _c .

For example, the precipitation phase may be formed by the base element, the sintered element, or both in the alloying process of the entanglement alloy matrix composite material and / or by the addition of the element for precipitation formation before or after the formation of the mechanical alloying powder . Or by heat treatment after sintering and / or sintering of the mechanical alloying powder.

For example, the precipitation phase forming element may be the same as or different from the base element, and specifically, Co, Cr, Fe, Mn, Cu, Mo, V, Nb, Ni, Al, Si, Ti, Zr And at least one selected from the group consisting of Ta, Mg, Be, Ba, Zn, Cr, Y, Sn, W, Hf, V, Nb, Ta, Mo, W, Ta, La, , The base element; And / or more than 0 mol% and not more than 300 mol% with respect to the sintered element forming alloy element; And preferably from 1 mol% to 100 mol%.

As an example of the present invention, the average VEC of the entantopy alloy base composite material is 10 or less; Preferably 5 to 8; And more preferably from 6 to 7.5 since the base alloy element forms the FCC structure, so that the average VEC of the alloy is lowered by injecting the element having a lower VEC than that of the base alloy element, so that the BCC structure and the FCC Structure can be formed at the same time. For example, by lowering the average VEC of the composite material, it is possible to prevent cold welding or the like between the base alloying elements during the mechanical alloying process.

The present invention relates to a method of manufacturing a high entropy alloy matrix composite material, wherein the manufacturing method according to an embodiment of the present invention is a method for manufacturing a high entropy alloy matrix composite material, It is possible to improve the alloy yield and mechanical strength of the entropy alloy base composite material and to further form the precipitation phase, thereby improving the high temperature characteristics of the entanglement alloy base composite material.

According to one embodiment of the present invention, the manufacturing method refers to FIG. 1, wherein FIG. 1 illustrates an exemplary flow chart of a method of manufacturing a high entropy alloy matrix composite material of the present invention, according to an embodiment of the present invention . 1, the manufacturing method includes: preparing (110) a mixed powder; Forming an alloyed powder (120); And a high-temperature sintering step (130).

In one embodiment of the present invention, the step (110) of preparing a mixed powder comprises: And a sintering intermetallization-forming alloy element; and each of the elements is as described in the above-mentioned entropy alloy base composite material. The step 110 of preparing the mixed powder may utilize the powder mixing method used in the technical field of the present invention and is not specifically mentioned in this specification.

In one embodiment of the present invention, forming alloyed powder 120 is a step of forming a mechanical alloyed powder that mechanically alloys the mixed powder. The step (120) of forming the alloying powder may improve the yield of the alloy by preventing the phenomenon such as cold pressing of the powders during the mechanical alloying process by adding the element for forming the sintering filler metal, and prevent the contamination by the ball mill So that the inflow of impurities into the alloy can be prevented.

For example, in the step 120 of forming an alloyed powder, the sintering filler metal forming alloy element may be combined with at least a part of the base element so that the sintering filler metal forming alloy element may be dispersed in the alloy base. Alternatively, the sintering intermetallization forming alloy element may be combined with at least a part of the base element to further form a sintering intermetallic alloy, and the sintering intermetallic alloy may be further dispersed in the alloy matrix.

For example, step 110 of preparing the mixed powder may comprise the steps of: providing a reinforcement material and / or reinforcement constituent; Can be further added to prepare a mixed powder, and the reinforcing material is as mentioned above.

For example, forming 120 a mechanical alloying powder may be performed within 120 hours; 1 hour to 120 hours; Or 10 hours to 50 hours.

For example, forming (120) a mechanical alloying powder may include forming at least 50%; 60% or more; It is possible to provide a high entropy alloy matrix composite material with a yield of 80% or more or 90% or more.

For example, the step 120 of forming a mechanical alloying powder may utilize a high energy ball milling device, for example, a vibrating mill, a planetary mill, an induction mill, etc., no.

In one embodiment of the present invention, the high-temperature sintering step 130 is a high-temperature sintering step of the mechanical alloying powder, and the mechanical alloying powder may be sintered to form a bulk material. For example, the high-temperature sintering step 130 may be performed by atmospheric pressure sintering, reactive sintering, pressure sintering, isostatic sintering, gas pressure sintering, atmospheric pressure sintering, or high-temperature sintering.

For example, the hot sintering step 130 may comprise 50% to 99% of the melting point of the mechanical alloying powder; 50% to 80%; 60% to 80%; 70% to 80%; 50% to 70%; 60% to 70%; Or at a temperature of 50% to 60%.

For example, the hot sintering step 130 may be performed in an atmosphere containing at least one of air, nitrogen, carbon, and boron for 60 hours or less; 1 minute to 60 hours; 5 minutes to 10 hours; 5 minutes to 5 hours; Or sintering for 5 minutes to 1 hour.

In one embodiment of the present invention, a step 140 of adding a precipitating phase forming element may be further included, and a step 140 of adding a precipitating phase forming element may include a step 110 of preparing a mixed powder, After the step 120 of adding and mixing the phase-forming elements and / or forming the mechanical alloying powder, the element for precipitation phase formation is added and mixed with the mechanical alloying powder, and further mechanical alloying can be carried out if necessary.

For example, the step 140 of adding a precipitated phase forming element may include adding the base element; And / or greater than 0 mol% and not more than 300 mol% with respect to the sintered element forming alloy element; Preferably from 1 mol% to 100 mol%, of the precipitated phase forming element.

In one embodiment of the present invention, the method for producing a high entropy alloy matrix composite material may further include a step of forming a precipitate phase (150), wherein the step of forming a precipitate phase (150) After step 130, the sintered body is heat-treated to form a precipitate phase. For example, from 300 DEG C to 1500 DEG C for 60 hours or less; 1 minute to 60 hours; 10 minutes to 50 hours; 1 hour to 20 hours; Or for 1 hour to 10 hours to form a precipitate phase. When the temperature is within the range of the heat treatment temperature and time range, the precipitation phase is formed well and the high temperature characteristics of the alloy material can be improved. For example, the step of forming a precipitate phase 150 may be heat treated in an atmosphere comprising at least one of air, nitrogen, carbon, and boron.

While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. This is possible. Therefore, the scope of the present invention should not be limited by the described embodiments, but should be determined by the equivalents of the appended claims, as well as the appended claims.

Example 1

The alloy was mechanically alloyed for 24 hours using a planetary milling process and then added with 3 volume% Y ₂ O ₃ Al _{0 . 3} CoCrFeMnNi high entropy alloy powders were prepared. About 5.7 mol% of Al element was added as a BCC forming alloy element. The yield of the alloy powder is shown in Fig.

Next, sintering was performed at 900 ° C for 5 minutes by a discharge plasma sintering method to prepare an alloy sintered body. The microstructure (scanning electron microscopy, scanning electron microscopy), phase analysis, hardness and compressive strength of the obtained alloy sintered body after sintering were measured and shown in FIGS. 3 to 6.

Example 2

The alloy was mechanically alloyed for 24 h using a planetary milling process to obtain a TiC doped Al _{0 . 3} CoCrFeMnNi high entropy alloy powders were prepared. About 5.7 mol% of Al element was added as a BCC forming alloy element. The yield of the alloy powder is shown in Fig.

Next, sintering was performed at 900 ° C for 5 minutes by a discharge plasma sintering method to prepare an alloy sintered body. The microstructure (scanning electron microscope, scanning electron microscopy), phase analysis and hardness of the sintered alloy obtained after sintering were measured and shown in Figs. 3 to 5.

Example 3

Mechanical alloying for 24 h using a planetary mill process was performed to obtain Mo _{0 . 8} CoCrFeMnNi high entropy alloy powders were prepared. Mo element was added in an amount of about 13.8 mol% as a BCC forming alloy element. The yield of the alloy powder is shown in Fig.

Next, sintering was performed at 900 ° C for 5 minutes by a discharge plasma sintering method to prepare an alloy sintered body. Phase analysis and hardness of the alloy sintered body obtained after sintering were measured and shown in FIG. 3 and FIG.

Comparative Example 1

The alloy powder was prepared in the same manner as in Example 1 except that the CoCrFeNiMn high entropy alloy was formed, and the yield of the alloy powder was shown in Fig. Next, sintering was performed at 900 ° C for 5 minutes by a discharge plasma sintering method to prepare an alloy sintered body. The hardness of the alloy sintered body obtained by sintering was measured and shown in Fig.

Comparative Example 2

3 volume% Y ₂ O ₃ added CoCrFeNiMn composite entropy alloy was formed in the same manner as in Example 1, and the yield of the alloy powder was shown in FIG. Next, sintering was performed at 900 ° C for 5 minutes by a discharge plasma sintering method to prepare an alloy sintered body. The hardness of the alloy sintered body obtained by sintering was measured and shown in Fig.

2, the yields of 17.6% and 16.4% of the CoCrFeNiMn entropy alloy without the BCC alloy element Al of Comparative Example 1 and the CoCrFeNiMn entropy alloy with 3 volume% Y ₂ O ₃ of Comparative Example 2, respectively, 3 volume% Y ₂ O ₃ added in Example 1 Al _{0 . 3} CoCrFeMnNi high entropy alloy powder showed a high yield of 81.2%. This is because most of the powders are entangled in balls and containers due to cold pressure welding in the mechanical alloying process to lower the recovery of the alloy powder, but the 3 volume% Y ₂ O ₃ added-Al _0.3 CoCrFeMnNi The entropy alloy powder can improve the brittleness of the powder by the BCC alloy element Al to lower the cold pressing and obtain the alloy powder with a high yield.

3, in the X-ray diffraction graph showing the phase analysis of the alloy sintered body, in the sintered body produced in Example 3, Mo was added to form a BCC phase, and it was confirmed that precipitates including Cr, Mo, and Ni were formed .

Referring to FIG. 4, it can be confirmed that the reinforcement material is evenly dispersed in a scanning electron microscopic photograph showing the microstructure of the sintered alloys of Example 1 and Example 2. FIG.

5, the sintered product of the CoCrFeNiMn alloy of Comparative Example 1 and the sintered product of the 3 volume% Y ₂ O ₃ -containing CoCrFeNiMn alloy of Comparative Example 2 had an Al ₀ O _{3 content} of 3 volume% Y ₂ O ₃ of Example 1 _{. 3} CoCrFeMnNi alloy sintered body and the 5% by volume TiC-added Al _0.3 CoCrFeMnNi alloy sintered body of Example 2 were improved. Further, referring to FIG. 6, the 3 volume% Y ₂ O ₃ -added Al _{0 . 3} CoCrFeMnNi alloy sintered body has high compressive strength. This shows that the addition of BCC alloying element Al to the entropy alloy improves the powder yield and can also increase the mechanical properties by adding the BCC alloy element Al and the reinforcement.

The present invention can improve the mechanical properties and heat resistance of a high entropy alloy matrix composite material by injecting a sintering filler metal forming alloy element and a reinforcement material and improve the yield of the alloy powder by preventing cold pressing or the like during the mechanical alloying process.

Claims (14)

At least four base elements selected from the group consisting of Co, Cr, Fe, Ni, Mn, Cu, Mo, V, Nb, Ta, Ti, Zr, W, Si, Hf and Al; And
The method according to claim 1, wherein the metal element is selected from the group consisting of Co, Cr, Fe, Ni, Mn, Cu, Mo, V, Nb, Al, Si, Ti, Zr, Ta, Mg, Be, Ba, Zn, Cr, Y, Sn, W, An intermetallic compound including at least one of Ta, Mo, W, Ta, La, and B; / RTI >
Wherein the reinforcing material further comprises at least one selected from the group consisting of metal oxides, metal silicides, metal carbides, metal nitrides and metal borides.
The method according to claim 1,
Wherein the reinforcing material is contained in an amount of 0.01 to 50 volume% with respect to the high entropy alloy matrix composite material.
The method according to claim 1,
Wherein the precipitated phase comprises a sintering intermetallization forming alloy element.
The method of claim 3,
Wherein the sintered insulator forming alloy element has a valence electron concentration (VEC) value of 7 or less.
The method of claim 3,
Wherein the sintering intermetallization forming alloy element is different from the base element and contains at least one element selected from the group consisting of Al, Cr, Mn, Mo, Nb, Ta, Ti, Base composite material.
The method of claim 3,
Wherein the sintering filler metal forming alloy element is contained in an amount of 0.01 mol% to 90 mol% with respect to the high entropy alloy matrix composite material.
The method according to claim 1,
Wherein the high entropy alloy matrix composite material has a valence electron concentration (VEC) of 10 or less.
delete At least four base elements selected from the group consisting of Co, Cr, Fe, Ni, Mn, Cu, Mo, V, Nb, Ta, Ti, Zr, W, Si, Hf and Al; And a precipitated phase forming element;
Forming a mechanical alloying powder that mechanically alloys the mixed powder; And
High-temperature sintering the mechanical alloying powder;
Lt; / RTI >
The mechanical alloying powder forming step may be such that the sintering additive forming alloy element among the precipitated phase forming elements binds to at least a part of the base element,
Wherein the step of preparing the mixed powder further comprises adding a reinforcement material,
The reinforcing material is at least one of Al, Si, Ti, Zr, Ta, Mg, Be, Ba, Zn, Cr, Y, Sn, W, Hf, V, Nb, Ta, Mo, W, Ta, La, Wherein at least one selected from the group consisting of a metal oxide, a metal silicide, a metal carbide, a metal nitride, and a metal boride is contained.
10. The method of claim 9,
Wherein the step of forming the mechanical alloying powder is performed using a high energy ball milling apparatus and obtaining a high entropy alloy matrix composite material at a yield of at least 50%.
delete 10. The method of claim 9,
The precipitation phase forming element may be at least one element selected from the group consisting of Co, Cr, Fe, Ni, Mn, Cu, Mo, V, Nb, Al, Si, Ti, Zr, Ta, Mg, Be, Ba, Zn, And at least one selected from the group consisting of Hf, V, Nb, Ta, Mo, W, Ta, La and B.
10. The method of claim 9,
Further comprising a step of subjecting the mechanical alloying powder to high-temperature sintering, followed by heat treatment at 300 ° C to 1500 ° C to form a precipitate phase.
10. The method of claim 9,
Wherein the high temperature sintering of the mechanical alloying powder is performed at a temperature of 50% to 99% of the melting point of the mechanical alloying powder.

Images