KR20170027520A - Hight-entropy multioelement alloy with single phase and process for preparing the same - Google Patents
Hight-entropy multioelement alloy with single phase and process for preparing the same Download PDFInfo
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- 238000004519 manufacturing process Methods 0.000 title claims abstract description 19
- 229910045601 alloy Inorganic materials 0.000 title claims description 93
- 239000000956 alloy Substances 0.000 title claims description 93
- 229910052750 molybdenum Inorganic materials 0.000 claims abstract description 9
- 229910052758 niobium Inorganic materials 0.000 claims abstract description 9
- 229910052720 vanadium Inorganic materials 0.000 claims abstract description 9
- 229910052715 tantalum Inorganic materials 0.000 claims abstract description 8
- 229910052804 chromium Inorganic materials 0.000 claims abstract description 7
- 229910052719 titanium Inorganic materials 0.000 claims abstract description 7
- 229910052721 tungsten Inorganic materials 0.000 claims abstract description 7
- 229910052726 zirconium Inorganic materials 0.000 claims abstract description 7
- 229910052735 hafnium Inorganic materials 0.000 claims abstract description 6
- 229910052702 rhenium Inorganic materials 0.000 claims abstract description 6
- 239000000203 mixture Substances 0.000 claims description 29
- 239000000843 powder Substances 0.000 claims description 28
- 239000011812 mixed powder Substances 0.000 claims description 26
- 238000000034 method Methods 0.000 claims description 23
- 238000005245 sintering Methods 0.000 claims description 21
- 238000005551 mechanical alloying Methods 0.000 claims description 19
- 238000002156 mixing Methods 0.000 claims description 6
- 238000002149 energy-dispersive X-ray emission spectroscopy Methods 0.000 claims description 5
- 238000000713 high-energy ball milling Methods 0.000 claims description 5
- 238000003701 mechanical milling Methods 0.000 claims description 5
- 238000004611 spectroscopical analysis Methods 0.000 claims description 3
- 229910001325 element alloy Inorganic materials 0.000 abstract description 6
- 238000001878 scanning electron micrograph Methods 0.000 description 7
- 239000000463 material Substances 0.000 description 4
- 229910002059 quaternary alloy Inorganic materials 0.000 description 4
- RZJQYRCNDBMIAG-UHFFFAOYSA-N [Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Zn].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn] Chemical class [Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Cu].[Zn].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Ag].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn].[Sn] RZJQYRCNDBMIAG-UHFFFAOYSA-N 0.000 description 3
- 238000005275 alloying Methods 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 238000004458 analytical method Methods 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 238000005266 casting Methods 0.000 description 2
- 239000000470 constituent Substances 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 238000000265 homogenisation Methods 0.000 description 2
- 230000000704 physical effect Effects 0.000 description 2
- 239000006104 solid solution Substances 0.000 description 2
- 238000003786 synthesis reaction Methods 0.000 description 2
- 238000002441 X-ray diffraction Methods 0.000 description 1
- 238000000441 X-ray spectroscopy Methods 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 238000007542 hardness measurement Methods 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000003801 milling Methods 0.000 description 1
- 238000005453 pelletization Methods 0.000 description 1
- 125000003367 polycyclic group Chemical group 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000001308 synthesis method Methods 0.000 description 1
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- C22C—ALLOYS
- C22C30/00—Alloys containing less than 50% by weight of each constituent
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
- B22F3/10—Sintering only
- B22F3/105—Sintering only by using electric current other than for infrared radiant energy, laser radiation or plasma ; by ultrasonic bonding
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F9/00—Making metallic powder or suspensions thereof
- B22F9/02—Making metallic powder or suspensions thereof using physical processes
- B22F9/04—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C45/00—Amorphous alloys
- C22C45/10—Amorphous alloys with molybdenum, tungsten, niobium, tantalum, titanium, or zirconium or Hf as the major constituent
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F9/00—Making metallic powder or suspensions thereof
- B22F9/02—Making metallic powder or suspensions thereof using physical processes
- B22F9/04—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling
- B22F2009/043—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling by ball milling
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Abstract
Description
The present invention relates to a single-phase multi-element high entropy alloy and a method of manufacturing the same.
The multi-component high-entropy alloys (HEAs) are composed of four or more elements mixed in the same composition, for example, five or more different elements constituting the alloy in the composition, To form solid solution alloys.
For example, a method of manufacturing a hexagonal high entropy alloy (MoNbTaTiVW) using a vacuum arc melting method (B. Zhang, 'Senary refractory high entropy alloy MoNbTaTiVW' , Materials Science and Technology, 2015), and multi-component high-entropy alloying of materials that can increase the strength of the alloy by casting (Hongbin Bei, 'Multi-component Solid Solution Alloys Having High Mixing Entropy', US20130108502, Oct. 27, 2011) Was presented.
The polyanthene-based entropy alloys produced by this method are known to have the maximum enthalpy of constitutional entropy (that is, mixed entropy) when the constituent elements have the same atomic ratio, and because of their simple crystal structure, Although exhibiting unique physical and mechanical properties, the lattice is severely deformed due to differences in atomic size. In addition, since the microstructure of a polyphase such as a two-phase or a three-phase or more is formed rather than a single phase, heterogeneity and instability arise due to the difference in physical properties and stability between phases in the case of a polyphase high entropy alloy, There is a limited problem.
SUMMARY 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 single-phase, multi-entangled, high entropy alloy with improved uniformity and stability of materials and superior strength.
The present invention also provides a method of manufacturing a single-phase multi-element high entropy alloy, which provides the single-phase multi-element high entropy alloy.
The problems to be solved by the present invention are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood from the following description.
One aspect of the present invention relates to a single phase multi-element high entropy alloy containing at least four or more elements selected from the group consisting of W, Mo, Ti, V, Cr, Nb, Zr, will be.
According to an embodiment of the present invention, the polycrystalline high entropy alloy may be one selected from the group consisting of a quaternary alloy of WMoCrNb, WVCrTa, MoVCrNb, VCrZrTa or CrNbZrTa; NbMoVTaW, WMoVCrTa, WVCrNbTa, WVNbZrTa, MoVCrZrTa or VCrNbZrTa; Or a six-element alloy such as WMoVCrZrTa, WMoCrNbZrTa, WVCrZrHfTa, MoVCrZrReHf or VCrNbZrHfTa.
According to an embodiment of the present invention, each element in the polycrystalline high entropy alloy may be included in an amount of 5 to 35 mol%.
According to an embodiment of the present invention, the entropy of the multi-element high entropy alloy may be 10 J / mol or more.
According to one embodiment of the present invention, the polycyclic entropy alloy may have a hardness of 2 GPa or more.
Another aspect of the present invention is a method for producing a multi-component mixed powder, comprising: preparing a multi-component mixed powder for mixing at least four or more elements; Forming a mechanical alloying powder that mechanically alloys the mixed powder; And forming a single-phase high entropy alloy for high-temperature sintering the mechanical alloying powder; Wherein the element is selected from the group consisting of W, Mo, Ti, V, Cr, Nb, Zr, Re, Hf and Ta.
According to one embodiment of the present invention, the step of forming the mechanical alloying powder may be performed using a high energy ball milling apparatus.
According to one embodiment of the present invention, the powder after the step of forming the mechanical alloying powder comprises a body centered cubic, a face centered cubic and a hexagonal closed packed structure Lt; RTI ID = 0.0 > entropy < / RTI >
According to an embodiment of the present invention, the step of forming the high entropy alloy may be performed using a discharge plasma sintering apparatus.
According to an embodiment of the present invention, preparing the multi-component mixed powder may include preparing at least four or more elements in an equimolar molar ratio to prepare a premix powder; Mechanical milling and high-temperature sintering the pre-mixed powder to form a poly-phase strongly entropy alloy; Confirming the element composition ratio of the single phase region containing the at least four elements among the polyphase high entropy alloys; Preparing a multi-component mixed powder containing at least four elements according to an element composition ratio of the single phase region obtained in the step of confirming the element composition ratio of the single phase region; . ≪ / RTI >
According to an embodiment of the present invention, the step of confirming the element composition ratio of the single phase region can be performed by energy dispersion spectrometry or wavelength dispersive spectroscopy.
The present invention can provide a single phase multi-element high entropy alloy having superior uniformity and stability of material and increased strength more than twice as compared with multi-element high entropy alloy manufactured by conventional casting method.
The present invention does not require the addition of a high-temperature heat treatment step necessary for microstructure homogenization in the conventional manufacturing method, realizing microstructure homogenization of an alloy by mechanical alloying and sintering of a single-phase multi-element high entropy alloy, The economical efficiency of the manufacturing process and the manufacturing cost can be improved.
The present invention can easily produce a single phase high entropy alloy by analyzing the element composition ratio of a single phase in a polyphase high entropy alloy in a simple manner and applying it to the production of a single phase high entropy alloy.
FIG. 1 illustrates a flow chart of a method for manufacturing a single-phase multi-element high entropy alloy according to an embodiment of the present invention.
FIG. 2 is a flow chart illustrating a method of manufacturing a single-phase multi-element high entropy alloy according to an embodiment of the present invention.
FIG. 3 shows an SEM image of a polyphase multi-entangled alloy produced according to an embodiment of the present invention.
FIG. 4 shows an SEM image of a single-phase multi-element high entropy alloy produced by an embodiment of the present invention.
FIG. 5 shows XRD patterns of a single-phase multi-element high entropy alloy produced by an embodiment 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.
The present invention provides a single-phase multi-entangled high entropy alloy, which forms a single phase due to a high mixed entropy effect between the constituent elements, and is superior in uniformity and stability, Strength characteristics can be shown.
According to an embodiment of the present invention, the single-phase multi-element high entropy alloy includes four or more elements; 5 or more elements; Or 6 or more elements; And the like. For example, the element may be selected from the group consisting of W, Mo, Ti, V, Cr, Nb, Zr, Re, Hf and Ta as long as it is an element capable of forming a polycrystalline and entropy alloy. . For example, the single-phase high entropy alloy may be a quaternary alloy of any one of WMoCrNb, WVCrTa, MoVCrNb, VCrZrTa or CrNbZrTa; NbMoVTaW, WMoVCrTa, WVCrNbTa, WVNbZrTa, MoVCrZrTa or VCrNbZrTa; Or a six-element alloy such as WMoVCrZrTa, WMoCrNbZrTa, WVCrZrHfTa, MoVCrZrReHf or VCrNbZrHfTa.
According to an embodiment of the present invention, the composition ratio of each element in the single-phase multi-element high-entropy alloy may be appropriately selected according to the number, types, etc. of elements constituting the single phase, To 35 mol%; 5 to 30 mol%; 5 to 25 mol%; 5 to 20 mol%; 8 to 35 mol%; 10 mol% to 35 mol%; 15 to 35 mol%; 8 to 30 mol%; Or 10 to 20 mol%; Lt; / RTI > According to an embodiment of the present invention, each element in a single phase multi-element high entropy alloy comprises, for example, from 18 mol% to 20 mol% of Nb, from 10 mol% to 13 mol% of Mo, from 32 mol% to 35 mol% But is not limited thereto, preferably 19.3% by mole of Nb, 11.9% by mole of Mo, 33.6% by mole of V, 25% by mole of Ta, 28% , 27.1% by mole of Ta, and 8.1% by mole of W, respectively. In another method of manufacturing a single-phase multi-entangled alloy according to another aspect of the present invention, an alloy is prepared by using a pre-mixed powder and confirmed through a process of confirming a single-phase composition ratio through the process. In this case, the alloy has a five-element single phase in its entirety.
According to an embodiment of the present invention, the entropy of the single phase multi-entangled high entropy alloy can be changed according to the kind of the elements constituting the alloy, and for example, the alloy has a Joule of 10 J / mol or more; 11 J / mol or more; Or 10 to 14 J / mol; Of the entropy. For example, the quaternary alloy is 10 J / mol to 12 J / mol, preferably 10 J / mol to 11.55 J / mol, the quaternary alloy has 12 J / mol to 14 J / mol, Can be from 12 J / mol to 13.5 J / mol.
According to one embodiment of the present invention, the hardness of the single phase multi-element high entropy alloy is at least 2 GPa; 5 GPa or higher; 6 GPa or higher; 2 to 20 GPa; 6 to 20 GPa; 10 GPa to 20 GPa; Or 10 GPa to 15 GPa.
The present invention provides a method of manufacturing a single phase multi-entangled high entropy alloy of the present invention, which can provide a single phase high entropy alloy having improved hardness by using mechanical alloying and high temperature sintering.
Referring to FIG. 1, a method of manufacturing a single-phase multi-element high entropy alloy according to an embodiment of the present invention is illustrated. In FIG. 1, the multi- (S1), forming a mechanical alloying powder (S2), and forming a single-phase high entropy alloy (S3); . ≪ / RTI >
The step (S1) of preparing the multi-component mixed powder is a step of preparing the multi-component mixed powder by mixing the respective elements in a predetermined amount according to the desired high entropy alloy.
Referring to FIG. 2, in accordance with an embodiment of the present invention, FIG. 2 illustrates a method of manufacturing a single phase, multi-element high entropy alloy, wherein step S1 in FIG. Step S1a of forming a multiphasic entanglement alloy, step S1b of forming a multiphasic entropy alloy, step S1c of checking the element composition ratio of the single phase region, and preparing a multiphase mixed powder S1d. Since the single-phase high-entropy alloy is manufactured using the composition ratio after analyzing the element composition ratio of the single-phase region in the poly-phase high-entropy alloy, the step S1 can more accurately predict the atomic ratio of the single- A single phase alloy can be produced. Further, the process of the single entangled high entropy alloy can be simplified and the economical efficiency of the process can be improved.
The step (S1a) of preparing the preliminarily mixed powder is a step of preparing the preliminarily mixed powder by mixing the respective elements in an equimolar mole% according to the desired high entropy alloy. According to one embodiment of the present invention, the element includes at least four kinds or more; Five or more elements; Or 6 or more; Mo, Ti, V, Cr, Nb, Zr, Re, or the like can be used as long as it is an element capable of forming a multi-element high entropy alloy. , Hf, and Ta.
The step (S1b) of forming a polyanthelophilic entropy alloy is a step of mechanically milling and sintering the preliminarily mixed powder obtained in the step (S1a) to form a polyphase high entropy alloy. According to one embodiment of the present invention, the mechanical milling can utilize a high energy ball milling apparatus such as a vibrating mill, a planetary mill, and an attrition mill. The mechanical alloying powder formed in step S1b may be formed of an amorphous, crystalline structure or a powder having both, for example, a body centered cubic, a face centered cubic and a dense A hexagonal closed packed structure, and a crystalline high entropy powder having at least one structure selected from the group consisting of hexagonal closed packed structures. The high-temperature sintering may be performed in an air or gas atmosphere; Or a vacuum state, and the high-temperature sintering is performed at a temperature of 1200 ° C or higher; 1300 ° C or higher; 1200 ° C to 1800 ° C; 1300 ° C to 1800 ° C; 1400 ° C to 1800 ° C; Or a temperature of 1500 ° C to 1800 ° C; Lt; / RTI > The high-temperature sintering is performed for 5 minutes or more; 1 hour or more; 2 hours or more; 1 hour to 6 hours; 1 hour to 5 hours; Or 2 hours to 4 hours; ≪ / RTI > The high-temperature sintering can be used without restriction as long as it is a sintering apparatus capable of alloying, and preferably a discharge plasma sintering apparatus can be used.
When the pre-mixed powder is subjected to mechanical milling and high-temperature sintering, there are many polyphase regions as a whole, and some of the regions contain only a few components, so that the entropy value is low and the physical properties required for a single- . However, in some areas, a single-phase region appears with a high entropy value including a multi-component system at a specific component ratio. The following step is a process for identifying the element composition ratio by searching for a region including both the single-phase and multi-element elements.
The step (S1c) of confirming the element composition ratio of the single phase region is a step of confirming the element composition ratio for forming a single phase by measuring the element composition ratio in the microstructure region of each phase in the multiphase high entropy alloy sintered body.
According to an embodiment of the present invention, step S1c is a step of observing the microstructure of the alloy sintered body by transmission electron microscope (TEM), scanning electron microscope (SEM) or the like, The composition ratio of elements such as regions, crystal grains and interfaces is measured by Energy Dispersive X-ray Spectroscopy (EDS) or Wave Dispersive X-ray Spectroscopy (WDS) Element composition ratio can be analyzed.
The step of preparing the multi-component mixed powder (S1d) is a step of preparing a multi-component mixed powder containing at least four elements according to the element composition ratio of the single-phase region obtained in the step S1c. The element is as mentioned in step S1a.
The step (S2) of forming the mechanical alloying powder is a step of mechanically alloying the multi-component mixed powder obtained in step (S1) to form a mechanical alloying powder, and the mechanical alloying is as mentioned in step (S1b). The mechanical alloying powder obtained in step S2 may be formed of amorphous, crystalline, or powder having both, for example, a body centered cubic, a face centered cubic, A hexagonal closed packed structure, and a crystalline high entropy powder having at least one structure selected from the group consisting of hexagonal closed packed structures.
The step (S3) of forming a single phase high entropy alloy is a step of high-temperature sintering the mechanical alloying powder obtained in the step (S2) to form a single-phase mechanical alloy sintered body, As shown above. Since the mixed powders are prepared according to the composition ratio of the single phase through the steps S1a to S1c, the single phase multi-phase high entropy alloy is formed as a whole.
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.
Example
(1) Analysis of atomic ratio of single phase region after mechanical milling and high temperature sintering of premixed powder
The mixed powders composed of W, Nb, Mo, Ta and V in the same mol% were put into a high energy ball milling machine (Fritsch, Pulverisette) and mechanically alloyed at a room temperature and 300 rpm for a maximum of 40 hours to obtain a high entropy powder. This was placed in a discharge plasma sintering apparatus (SCM, Co., Dr. Sinter 515-S) and maintained at 1700 ° C for 10 minutes (heating rate: 100 ° C per minute) to prepare a sintered body. The sintered body thus produced as a whole is a poly-phase alloy of W 20 Nb 20 Mo 20 Ta 20 V 20 . An SEM image of the sintered alloy is shown in FIG. It can be seen from the SEM image of FIG. 3 that a multi-phase multi-component alloy is formed. The composition ratios of the elements in the dark (A) region, the gray (B) region and the bright (c) region in the SEM image of FIG. 3 were analyzed by energy dispersive spectroscopy (EDS)
(2) Single-phase high-entropy alloy synthesis
From the results of the composition analysis in Table 1, it can be seen that only dark (A) among the three phases has the composition of a high entropy alloy. Mixed powders of W, Nb, Mo, Ta and V at the composition ratio measured in the dark (A) region were put into a high energy ball milling machine and mechanically alloyed at room temperature for up to 40 hours at 300 rpm to obtain a single phase high entropy alloy powder Respectively. The alloy sintered body was prepared by pelletizing it in a plasma sintering apparatus at 1700 ° C. for 10 minutes (100 ° C. per minute at a heating rate of 100 ° C.). An image and an SEM image of the sintered body are shown in FIG. 4, and it can be confirmed that a single phase alloy is formed in the SEM image. The XRD of the high entropy powder (a) after the mechanical alloying and the sintered product (b) after high-temperature sintering were measured and shown in Fig. It can be confirmed that the high entropy powder (a) and the alloy sintered body (b) are formed of a single-phase high entropy alloy as the regularity of the XRD peak follows the bcc structure with one lattice constant.
Experimental Example
The Vickers hardness measurement method was used to measure the hardness of the single-phase high-entropy alloy of the examples, and as a result, 11.9 GPa was measured.
The present invention can provide a single-phase, multi-entangled, entropy alloy having increased hardness significantly compared to conventional entropype synthesis methods using mechanical alloying and high-temperature sintering. Further, since the atomic composition ratio of the single-phase high-entropy alloy can be calculated by a simple method using the multi-phase high-entropy alloy, it is possible to reduce the synthesis step and cost of the single-phase high entropy alloy.
Claims (11)
The multi-entangled high entropy alloy is characterized in that,
WMoCrNb, WVCrTa, MoVCrNb, VCrZrTa, or CrNbZrTa;
NbMoVTaW, WMoVCrTa, WVCrNbTa, WVNbZrTa, MoVCrZrTa or VCrNbZrTa; or
WMoVCrZrTa, WMoCrNbZrTa, WVCrZrHfTa, MoVCrZrReHf, or VCrNbZrHfTa, which is a hexagonal system high entropy alloy.
Wherein each element in the polycrystalline high entropy alloy is contained in an amount of 5 to 35 mol%.
Wherein the entropy of the multi-element high entropy alloy is at least 10 J / mol.
Wherein the single phase multi-element high entropy alloy has a hardness of 2 GPa or more.
Forming a mechanical alloying powder that mechanically alloys the mixed powder; And
Forming a single-phase high entropy alloy which sinters the mechanical alloying powder at high temperature; Lt; / RTI >
Wherein the element is selected from the group consisting of W, Mo, Ti, V, Cr, Nb, Zr, Re, Hf and Ta.
(METHOD FOR MANUFACTURING.
Wherein the step of forming the mechanical alloying powder is performed using a high energy ball milling apparatus.
The powder after the step of forming the mechanical alloying powder may have at least one structure selected from the group consisting of a body centered cubic, a face centered cubic, and a hexagonal closed packed structure. Wherein the high entropy powder is a high entropy powder.
Wherein the step of forming the high entropy alloy is performed using a discharge plasma sintering apparatus.
Preparing the multi-component mixed powder comprises:
Mixing at least four or more elements in an equimolar molar ratio to prepare a preliminary mixed powder;
Mechanical milling and high-temperature sintering the pre-mixed powder to form a poly-phase strongly entropy alloy;
Confirming the element composition ratio of the single phase region containing the at least four elements among the polyphase high entropy alloys; And
Preparing a multi-component mixed powder containing at least four elements according to an element composition ratio of the single phase region obtained in the step of confirming the element composition ratio of the single phase region;
≪ / RTI >
(METHOD FOR MANUFACTURING.
Wherein the step of confirming the element composition ratio of the single phase region is performed by energy dispersive spectroscopy or wavelength dispersive spectroscopy.
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| CN107267842A (en) * | 2017-06-26 | 2017-10-20 | 北京理工大学 | A kind of high-melting-point high-entropy alloy and preparation method thereof |
| CN107267841A (en) * | 2017-06-14 | 2017-10-20 | 湘潭大学 | A kind of CrMoNbTaV high-entropy alloys and preparation method thereof |
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| JP4190720B2 (en) | 2000-11-29 | 2008-12-03 | 國立清華大學 | Multi-component alloy |
| US9150945B2 (en) | 2011-10-27 | 2015-10-06 | Ut-Battelle, Llc | Multi-component solid solution alloys having high mixing entropy |
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