Patent Application
20240093338
The present invention claims the benefit of the filing date of Korean Patent Application No. 10-2022-0039117, filed on Mar. 29, 2022, in the Korean Intellectual Property Office, the entire content of which is included in the present invention.
The present disclosure relates to a healable superplastic amorphous alloy, and specifically, to a healable superplastic amorphous alloy capable of exhibiting superplastic behavior and unique healable behavior by maximizing the complexity of the amorphous structure for an Icosahedral quenched-in nuclei quasi-crystal cluster to be formed in the amorphous matrix through the composition limitation and additive element control of Zr—Cu—Ni—Al alloy.
In general, amorphous alloys have high strength and elastic limits (about 2%) compared to crystalline metal materials, and have been widely used for high-quality structural materials thanks to their excellent physical properties.
However, amorphous materials hardly exhibit ductility at or below the amorphous transition temperature, and there are restrictions on commercialization due to limitations in mechanical reliability caused by low fracture toughness. In order to improve the ductility of amorphous alloys, methods of forming shear bands or locally causing structural dilatation by imparting deformation to the material as a post-treatment process have been utilized, but due to the nature of resulting structure, the degree of ductility increase is extremely small while bringing about deterioration of material strength, which causes deterioration in essential characteristics of structural materials, such as fatigue strength and toughness, resulting in the limitation of their use.
Accordingly, the present disclosure is to provide an amorphous alloy which has a superplastic behavior similar to that of crystalline and is imparted with a unique healable property, thereby dramatically improving the mechanical stability and service life thereof.
The technical object to be achieved by the present disclosure is to provide an amorphous alloy which has a superplastic behavior similar to that of crystalline while being imparted with a unique healable property, thereby dramatically improving the mechanical stability and service life thereof, by maximizing the complexity of the amorphous structure by forming Icosahedral quenched-in nuclei (IQN) within the amorphous matrix in a composition with a high content of Zr through precise composition control and additive element control based on Zr—Cu—Ni—Al quaternary alloy, from the fact that bulk amorphous alloys with medium-range order clusters have relatively excellent elongation properties.
However, the objects to be addressed by the present disclosure are not limited to the above-mentioned problems, and problems other than mentioned above will be clearly appreciated by those skilled in the art from the following description.
An embodiment of the present disclosure provides a healable superplastic amorphous alloy including Zr, Cu, Ni, Al and an additive element, wherein the Ni and the Zr form a cluster, the additive element and the cluster form an Icosahedral quenched-in nuclei (IQN) quasi-crystal cluster, and the radius of the additive element is 75% or more and 105% or less with respect to the atomic radius of the Zr.
The healable superplastic amorphous alloy according to an embodiment of the present disclosure can exhibit superplastic behavior similar to that of crystalline even at room temperature, thereby improving mechanical stability.
Additionally, even when being subjected to local deformation up to the plastic deformation region by the formation of a shear band in an extreme use environment, the healable superplastic amorphous alloy according to an embodiment of the present disclosure can restore characteristics through healing by application of external energy.
Effects of the present disclosure are not limited to the above-described effects, but effects other than described above will be clearly appreciated by those skilled in the art from the present specification and accompanying drawings.
Throughout this specification, when a part “includes” or “comprises” a component, it means not that the part excludes other component, but instead that the part may further include other component unless expressly stated to the contrary.
Throughout the specification, when a member is described as being located “on” another member, this includes not only a case in which the member is in contact with the other member but also a case in which another member exists between the two members.
Throughout the present specification, the term “at. %” may mean the composition ratio of the number of atoms.
Throughout this specification, the phrase “A and/or B” refers to “A and B, or A or B.”
Throughout the present specification, the term “bulk” may mean having a thickness of 1 mm or more, or an amorphous forming ability of a critical cooling rate of 103 K/s or less.
Hereinafter, the present disclosure will be described in more detail.
An embodiment of the present disclosure provides a healable superplastic amorphous alloy including Zr, Cu, Ni, Al and an additive element, wherein the Ni and the Zr form a cluster, the additive element and the cluster form an Icosahedral quenched-in nuclei (IQN) quasi-crystal cluster, and the radius of the additive element is 75% or more and 105% or less with respect to the atomic radius of the Zr.
Throughout the present specification, the term “cluster” may refer to what the Ni and the Zr form, and the term “quasi-crystal cluster” may refer to an Icosahedral quenched-in nuclei (IQN) quasi-crystal cluster formed by the additive element and the cluster.
Throughout the present specification, the term “bulk” may mean having a thickness of 1 mm or more and having an amorphous forming ability equal to or greater than the boundary thickness at which brittleness occurs during mechanical deformation.
The healable superplastic amorphous alloy according to an embodiment of the present disclosure can have superplastic behavior similar to that of crystalline even at room temperature, thereby improving mechanical stability.
Even when being subjected to local deformation up to the plastic deformation region by the formation of a shear band, the healable superplastic amorphous alloy according to an embodiment of the present disclosure can restore characteristics through healing by application of external energy due to the role of the Icosahedral quenched-in nucleus as a healing core.
According to an embodiment of the present disclosure, the healable superplastic amorphous alloy includes Zr, Cu, Ni, Al and an additive element. As described above, by the healable superplastic amorphous alloy including Zr, Cu, Ni, Al and an additive element, it is possible as will be described later to implement unique healable property while having a superplastic behavior similar to that of crystalline, by forming a cluster between the Zr and the Ni and by maximizing the complexity of the amorphous structure by causing the cluster to form Icosahedral quenched-in nuclei (IQN) in a composition with a high content of Zr.
According to an embodiment of the present disclosure, Zr may be used as the additive element separately from the Zr included in the healable superplastic amorphous alloy. As described above, by using Zr as the additive element separately from the Zr included in the healable superplastic amorphous alloy, it is possible to exhibit unique healable property while having a superplastic behavior similar to that of crystalline, by maximizing the complexity of the amorphous structure by controlling the stability of the cluster to form an Icosahedral quenched-in nuclei quasi-crystal cluster under the condition of forming a cluster (Principal cluster) formed only of the Ni and the Zr in the matrix.
According to an embodiment of the present disclosure, in the healable superplastic amorphous alloy, the Ni and the Zr form a cluster. Specifically, in the healable superplastic amorphous alloy, the Ni and the Zr are mainly connected to form a principal cluster. As described above, when the Ni and the Zr form a cluster, the complexity of the amorphous structure inside the healable superplastic amorphous alloy can be increased.
According to an embodiment of the present disclosure, in the healable superplastic amorphous alloy, the additive element and the cluster form an Icosahedral quenched-in nuclei (IQN) quasi-crystal cluster. Specifically, in the healable superplastic amorphous alloy, an additive element is disposed between clusters formed of the Ni and the Zr to connect the clusters to each other, and the clusters form Icosahedral quenched-in nuclei (IQN) quasi-crystal clusters by the additive element (Glue atom), so that the healable superplastic amorphous alloy can have a superplastic behavior similar to that of crystalline even at room temperature while exhibiting a unique healable property.
According to an embodiment of the present disclosure, the radius of the added element is 75% or more and 105% or less with respect to the atomic radius of the Zr. Specifically, the radius of the additive element is 76% or more and 104% or less, 77% or more and 103% or less, 78% or more and 102% or less, 79% or more and 101% or less, 80% or more and 102% or less, 81% or more and 101% or less, 82% or more and 100% or less, 85% or more and 97% or less, 88% or more and 95% or less, or 89% or more and 93% or less, with respect to the atomic radius of Zr. Preferably, the radius of the additive element may be 90.2% with respect to the atomic radius of the Zr. Specifically, by implementing that the radius of the additive element is 75% or more and 105% or less with respect to the atomic radius of the Zr, the additive element can effectively adhere between clusters (principal clusters) formed of the Ni and the Zr. As described above, adjusting the radius of the additive element to 75% or more and 105% or less with respect to the atomic radius of the Zr can prevent rapid crystallization due to excessive adhesion of the cluster to one additive element caused by the excessively large radius of the additive element, and can prevent that the clusters are not connected to each other because the radius of the additive element is small.
According to an embodiment of the present disclosure, the additive element may be one selected from the group consisting of Zr, V, Ir, Mo, Re, Pd, Nb, Ta, Au, Ag, Ti, Hf, and combinations thereof. Specifically, Table 1 below is a table showing, as ratios, the differences between the ideal atomic radii of additive elements and the radii of the additive elements. That is, the above elements corresponding to ±10% difference from the ideal atomic radius are listed. When this is converted into a radius size ratio relative to the atomic radius of the Zr, it corresponds to 75% or more and 105% or less with respect to the atomic radius of the Zr. Referring to Table 1 below, since the atoms corresponding to 75% or more and 105% or less with respect to the atomic radius of the Zr, more preferably, 80% or more and 100% or less with respect to the atomic radius of the Zr correspond to Zr, V, Ir, Mo, Re, Pd, Nb, Ta, Au, Ag, Ti, and Hf, the quasi-crystal cluster can be easily formed by selecting the additive element and adhering the clusters to each other. As described above, by using, as the additive element, one selected from the group consisting of Zr, V, Ir, Mo, Re, Pd, Nb, Ta, Au, Ag, Ti, Hf, and combinations thereof, the additive element can easily form an Icosahedral quenched-in nuclei (IQN) quasi-crystal cluster in an amorphous matrix by adhering between the clusters (Principal clusters) formed by the Ni and the Zr.
According to an embodiment of the present disclosure, the content of the Al may be 6 at. % or more and 18 at. % or less. As described above, by adjusting the content of the AI to 6 at. % or more and 18 at. % or less, it can be adjusted so that excellent amorphous forming ability is realized in the superplastic amorphous alloy, and if the content is out of the range, the amorphous forming ability may be rapidly lowered.
According to an embodiment of the present disclosure, the critical cooling rate of the cooling process of the molten metal of the healable superplastic amorphous alloy may be 100 K/s or more and 106 K/s or less. As described above, by adjusting the critical cooling rate of the cooling process of the molten metal of the healable superplastic amorphous alloy to 100 K/s or more and 106 K/s or less, the alloy of the aforementioned specific composition can be implemented in an amorphous structure.
According to an embodiment of the present disclosure, in the cooling process of the molten metal of the healable superplastic amorphous alloy, the thickness of the molten metal may be 10 μm or more and 20 mm or less. Specifically, in the cooling process of the molten metal of the healable superplastic amorphous alloy, by implementing the thickness of the molten metal of 10 μm or more and 20 mm or less, the critical cooling rate of the cooling process of the molten metal of the healable superplastic amorphous alloy may be adjusted to be 100 K/s or more and 106 K/s or less. As described above, by adjusting the thickness of the molten metal to be 10 μm or more and 20 mm or less in the cooling process of the molten metal of the healable superplastic amorphous alloy, an appropriate critical cooling rate is realized, so that the alloy of the specific composition can be implemented in an amorphous structure.
According to an embodiment of the present disclosure, the critical cooling rate of the cooling process of the molten metal of the healable superplastic amorphous alloy may be 100 K/s or more and 106 K/s or less, wherein when the additive element is Zr, the content of Zr may be greater than 68 at. % and less than or equal to 73 at. %, the content of Ni may be 2 at. % or more and 24 at. % or less, the content of Cu may be 2 at. % or more and 24 at. % or less, and the content of Al may be 6 at. % or more and 18 at. % or less. Alternatively, in the cooling process of the molten metal of the healable superplastic amorphous alloy, the thickness of the molten metal may be 10 μm or more and 20 mm or less, wherein when the additive element is Zr, the content of the Zr may be greater than 68 at. % and less than or equal to 73 at. %, the content of the Ni may be 2 at. % or more and 24 at. % or less, the content of the Cu may be 2 at. % or more and 24 at. % or less, and the content of the Al may be 6 at. % or more and 18 at. % or less.
According to an embodiment of the present disclosure, the critical cooling rate of the cooling process of the molten metal of the healable superplastic amorphous alloy may be 100 K/s or more and 106 K/s or less, wherein when the additive element is an element other than Zr, the content of Zr may be 59 at. % or more and 68 at. % or less, the content of Ni may be 2 at. % or more and 29 at. % or less, and the content of Cu may be 2 at. % or more and 29 at. % or less, and the content of Al may be 6 at. % or more and 18 at. % or less. Alternatively, in the cooling process of the healable superplastic amorphous alloy, the thickness of the molten metal may be 10 μm or more and 20 mm or less, wherein when the additive element is an element other than Zr, the content of the Zr may be 59 at. % or more and 68 at. % or less, the content of the Ni may be 2 at. % or more and 29 at. % or less, the content of the Cu may be 2 at. % or more and 29 at. % or less, and the content of the Al may be 6 at. % or more and 18 at. % or less.
According to an embodiment of the present disclosure, the healable superplastic amorphous alloy may be represented by Formula 1.
ZraCub-cXcNidAlf [Formula 1]
where X is one selected from the group consisting of V, Mo, Nb, Ta, Ag, Ti, Hf, and combinations thereof, b−c is 2 or more and 29 or less, c is 1 or more and 10 or less, d is 2 or more and 29 or less, f is 6 or more and 18 or less, and a is 100−(b+d+f).
As described above, by selecting the amorphous alloy corresponding to Formula 1, an amorphous structure having Icosahedral quenched-in nuclei quasi-crystal clusters can be formed in the alloy, and the mechanical strength of the alloy at room temperature can be maintained while, at the same time, the ductility can be improved.
According to an embodiment of the present disclosure, Equation 1 below may be satisfied for X in Formula 1 above.
⅓(at. % of Ti)+⅓(at. % of Nb)+⅓(at. % of Ta)+⅓(at. % of Mo)+ 1/7(at. % of V)+ 1/7(at. % of Hf)+⅙(at. % of Ag)≥1.0 [Equation 1]
As described above, when the amorphous alloy components satisfy Equation 1 above for X in Formula 1 above, an amorphous structure having Icosahedral quenched-in nuclei quasi-crystal clusters can be formed in the alloy, and the mechanical strength of the alloy at room temperature can be maintained while, at the same time, the ductility can be improved.
According to an embodiment of the present disclosure, the healable superplastic amorphous alloy may be a bulk amorphous alloy having the critical cooling rate of 100 K/s or more and 103 K/s or less in the cooling process of the molten metal thereof. As described above, by adjusting the critical cooling rate of the cooling process of the molten metal of the healable superplastic amorphous alloy to 100 K/s or more and 103 K/s or less, the alloy of the aforementioned specific composition can be implemented as an amorphous structure in bulk form.
According to an embodiment of the present disclosure, in the cooling process of the molten metal of the healable superplastic bulk amorphous alloy, the thickness of the molten metal may be 1 mm or more and 20 mm or less. Specifically, in the cooling process of the molten metal of the superplastic bulk amorphous alloy, by implementing the thickness of the molten metal of 1 mm or more and 20 mm or less, the critical cooling rate of the cooling process of the molten metal of the healable superplastic bulk amorphous alloy may be adjusted to be 100 K/s or more and 103 K/s or less. As described above, in the cooling process of the molten metal of the superplastic bulk amorphous alloy, by adjusting the thickness of the molten metal to be 1 mm or more and 20 mm or less, an appropriate critical cooling rate is realized, so that the alloy of the specific composition can be implemented in an amorphous structure in bulk form.
According to an embodiment of the present disclosure, the critical cooling rate in the cooling process of the molten metal of the healable superplastic bulk amorphous alloy may be 100 K/s or more and 103 K/s or less, wherein when the additive element is Zr, the content of Zr may be greater than 68 at. % and less than or equal to 70 at. %, the content of Ni may be 5 at. % or more and 21 at. % or less, the content of Cu may be 5 at. % or more and 21 at. % or less, and the content of Al may be 6 at. % or more and 18 at. % or less. Alternatively, in the cooling process of the molten metal of the healable superplastic bulk amorphous alloy, the thickness of the molten metal may be 1 mm or more and 20 mm or less, wherein when the additive element is Zr, the content of Zr may be greater than 68 at. % and less than or equal to 70 at. %, the content of Ni may be 5 at. % or more and 21 at. % or less, the content of Cu may be 5 at. % or more and 21 at. % or less, and the content of Al may be 6 at. % or more and 18 at. % or less.
According to an embodiment of the present disclosure, the critical cooling rate in the cooling process of the molten metal of the healable superplastic bulk amorphous alloy may be 100 K/s or more and 103 K/s or less, wherein when the additive element is an element other than Zr, the content of Zr may be 59 at. % or more and 68 at. % or less, the content of Ni may be 5 at. % or more and 26 at. % or less, and the content of Cu may be 5 at. % or more and 26 at. % or less, and the content of Al may be 6 at. % or more and 18 at. % or less. Alternatively, in the cooling process of the molten metal of the healable superplastic bulk amorphous alloy, the thickness of the molten metal may be 1 mm or more and 20 mm or less, wherein when the additive element is an element other than Zr, the content of Zr may be 59 at. % or more and 68 at. % or less, the content of Ni may be 5 at. % or more and 26 at. % or less, the content of Cu may be 5 at. % or more and 26 at. % or less, and the content of Al may be 6 at. % or more and 18 at. % or less.
According to an embodiment of the present disclosure, the healable superplastic bulk amorphous alloy may be represented by Formula 2.
ZraCub-cX′cNidAlf [Formula 2]
where X′ is one selected from the group consisting of V, Mo, Nb, Ta, Ag, Ti, Hf, and combinations thereof, b−c is 5 or more and 26 or less, c is 1 or more and 8 or less, d is 5 or more and 26 or less, f is 6 or more and 18 or less, and a is 100−(b+d+f).
As described above, by selecting the healable superplastic bulk amorphous alloy corresponding to Formula 2, an amorphous structure having Icosahedral quenched-in nuclei quasi-crystal clusters can be formed in the alloy, and the mechanical strength of the alloy at room temperature can be maintained while, at the same time, the ductility can be improved.
According to an embodiment of the present disclosure, Equation 2 below may be satisfied for X′ in Formula 2 above.
⅓(at. % of Ti)+⅓(at. % of Nb)+⅓(at. % of Ta)+⅓(at. % of Mo)+ 1/7(at. % of V)+ 1/7(at. % of Hf)+⅙(at. % of Ag)≥1.0 [Equation 2]
As described above, when the healable superplastic bulk amorphous alloy components satisfy Equation 2 above for X′ in Formula 2 above, an amorphous structure having Icosahedral quenched-in nuclei quasi-crystal clusters can be formed in the alloy, and the mechanical strength of the alloy at room temperature can be maintained while, at the same time, the ductility can be improved.
According to an embodiment of the present disclosure, the cluster may be NiZr2. Specifically, the atoms forming the cluster may be the Zr and the Ni, and the atomic ratio of the Zr and the Ni may be 2:1. As described above, by implementing the cluster whose chemical formula is NiZr2, the coupling shape of the cluster can be adjusted, and the shape and size of the cluster can be adjusted by the additive element, so that clusters can be easily connected with each other to form the Icosahedral quasi-crystal cluster.
According to an embodiment of the present disclosure, in the cluster, the Ni and the Zr form a polyhedron, and the Ni may be disposed at the center of the polyhedron. Specifically, the polyhedron may be an icosahedron. More specifically, the one Ni atom may be provided at the center, and the remaining atoms may be located at vertices of the icosahedron to form a cluster. By forming the cluster as described above, the cluster easily forms an Icosahedral quenched-in nuclei quasi-crystal cluster by the additive element to maximize the complexity of the amorphous structure of the healable superplastic amorphous alloy, so that it can exhibit unique healable property while having a superplastic behavior similar to that of crystalline.
According to an embodiment of the present disclosure, the radius of the additive element may be 0.120 nm or more and 0.169 nm or less.
According to an embodiment of the present disclosure, the plastic deformation region of the healable superplastic amorphous alloy may be recovered by application of external energy including one selected from the group consisting of mechanical energy, electrical energy, thermal energy, magnetic energy, and combinations thereof.
According to an embodiment of the present disclosure, when the external energy is thermal energy, the thermal energy application may be a thermo-cycling process in which an environment of −50° C. or less and an environment of 100° C. or more are alternately performed at intervals of a time period of 20 seconds or more.
An embodiment of the present disclosure provides a method for preparing a healable superplastic amorphous alloy, the method including: forming a composition by mixing Zr, Cu, Ni, Al and an additive element; preparing an alloy by melting and then solidifying the composition.
The method for preparing a superplastic amorphous alloy according to an embodiment of the present disclosure maximizes the complexity of the amorphous structure, and can be implemented to exhibit unique healable characteristics while having a superplastic behavior similar to that of crystalline.
Hereinafter, the present disclosure will be described in detail with reference to examples. However, it should be noted that the examples according to the present disclosure may be modified into various other forms, and the scope of the present disclosure is not construed as being limited to the examples to be described below. The examples of the present specification are provided to more completely explain the present disclosure to those of ordinary skill in the art.
In the Zr—Cu—Ni—Al quaternary alloy group, after fixing the content of the Al to 12 at. %, while adjusting the content of the Ni and the content of the Cu as shown in Table 2 below, and adjusting the content of the Zr to have a remainder, a ribbon of 10 μm and a rod shape of 1 mm were prepared, and the content of the additive element was included in the content of the Zr. Thereafter, while adjusting the content of the Ni and the content of the Cu, the internal crystals of the bulk amorphous alloy were checked to determine whether there were superplastic behavior and quasi-crystal formation in the primary precipitated phase, and the results were summarized in Table 2 below. In the table below, the formation of quasi-crystal cluster is indicated by I-phase.
Referring to
Furthermore, referring to Table 2, for example, Zr63Cu7Ni18Al12, Zr65Cu7Ni16Al12, and Zr67Cu7Ni14Al12 do not form a quasi-crystal cluster (I-phase), and only Zr70Cu9Ni9Al12 and Zr69Cu9Ni10Al12 form a quasi-crystal cluster (I-phase).
While varying the content of Nb as an additive element with respect to the Zr63Cu14.5-cXcNi10.5Al12 composition, 100 μm ribbons were prepared, and subjected to differential scanning calorimetry and heat treatment, and then the structural analysis thereof was performed through X-ray diffraction analysis.
Referring to
A 2 mm rod-shaped specimen was prepared with the Zr70Cu9Ni9Al12 composition, and the results of X-ray diffraction analysis and differential scanning calorimetry (DSC analysis) of the prepared rod-shaped specimen were checked, and the X-ray diffraction analysis results were checked after heat treatment up to 435° C., which is the peak point of the first crystallization behavior of the 2 mm rod-shaped specimen of the Zr70Cu9Ni9Al12 composition.
2 mm rod-shaped specimens were prepared with the composition Zr70Cu9Ni9Al12, and differential scanning calorimetry was performed on the prepared specimens, and the prepared specimens after 10 healing cycles.
Referring to
A 2 mm rod-shaped specimen was prepared with the composition Zr70Cu9Ni9Al12 and a compression test was performed on it.
While varying the content of Nb as an additive element (X) with respect to Zr63Cu14.5-cXcNi10.5Al12 composition, 2 mm rod-shaped specimens were prepared and X-ray diffraction analysis was performed thereon. Furthermore, with respect to the Zr63Cu14.5-cXcNi10.5Al12 composition, differential scanning calorimetry was performed on the specimen with prepared amorphous state while changing the content of Nb as an additive element, and X-ray diffraction analysis was performed after heat treatment was performed up to the first crystallization behavior.
While changing the type and content of an additive element as shown in Table 3 below with respect to Zr63Cu14.5-cXcNi10.5Al12 composition, 10 μm ribbons were prepared and the results of differential scanning calorimetry were checked, and it was confirm that the quasi-crystal cluster was generated, and while changing the ratio of an additive element as shown in Table 4 below with respect to Zr65Cu15-cXcNi10Al10 composition, 2 mm rod-shaped specimens were prepared and the results of differential scanning calorimetry were checked, and it was confirm that the quasi-crystal cluster was generated. Whether quasi-crystal cluster (I-phase) was generated in the amorphous matrix was summarized in Tables 3 and 4. In the table below, the formation of quasi-crystal cluster is indicated by I-phase.
Referring to Table 3, it was confirmed that when the additive element was Mo, Ta, Ti, Zr, Ag, Hf, V, Pd, Pt, Au, or Ir, the quasi-crystal cluster was generated, while when the additive element was Si, Gd, or Y, the quasi-crystal cluster was not formed.
Referring to Table 4, it was confirmed that even when the additive element was added in various combinations, the quasi-crystal cluster was generated in the amorphous matrix.
While varying the content of Nb as an additive element (X) with respect to Zr63Cu14.5-cXcNi10.5Al12 composition, 2 mm rod-shaped specimens were prepared, and compression experiments were performed thereon.
Referring to
While varying the content of Nb as an additive element (X) with respect to Zr63Cu14.5-cXcNi10.5Al12 composition, 2 mm rod-shaped specimens were prepared, and after performing the compression experiment, differential scanning calorimetry was performed on the specimens that had undergone a healing cycle.
Referring to
While the present disclosure has been described by limited embodiments until now, the present disclosure is not limited by them, and various modifications can be made by those skilled in the art to which the present disclosure belongs within the equivalent scope of the technical idea of the present disclosure and the claims to be provided below.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2022-0039117 | Mar 2022 | KR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/KR2023/000758 | 1/16/2023 | WO |
