Aluminum alloy sheet

Abstract

The present disclosure relates to an aluminum alloy sheet manufactured by performing diffusion heat treatment on a layered structure of aluminum plates and titanium plates. Intermetallic compound layers may be formed in the aluminum alloy sheet by means of diffusion heat treatment, in response to which titanium atoms of the titanium plates are diffused, from the bonded boundaries between the aluminum plates and the titanium plates, into the aluminum matrices of the aluminum plates.

Description

aluminum alloy sheet

[0001] Various embodiments of the present disclosure relate to a method for manufacturing an aluminum alloy plate by diffusion heat treating an aluminum (Al) plate and a titanium (Ti) plate having a layered structure, and to an aluminum alloy plate manufactured thereby.

[0002] Electronic devices such as smartphones use metal exteriors to protect them from external impact or for aesthetic purposes. Aluminum alloy sheets are primarily used for the exteriors of these electronic devices. Depending on the manufacturing method, these aluminum alloy sheets can be categorized into cast aluminum alloy sheets and wrought aluminum alloy sheets.

[0003] Aluminum alloy sheets, which possess high strength due to the addition of additive elements (e.g., copper), are widely used not only in the automotive and aerospace industries but also as exterior materials for electronic devices. In addition to mechanical strength, aluminum alloy sheets that are smooth and glossy without surface defects are preferred for these electronic device exterior materials.

[0004] According to one embodiment of the present disclosure, an aluminum alloy plate manufactured by diffusion heat treating a layered structure in which an aluminum plate and a titanium plate are hot-welded can be formed by, in response to the diffusion heat treatment, titanium atoms of the titanium plate and aluminum atoms of the aluminum plate mutually diffuse with respect to the bonding boundary between the aluminum plate and the titanium plate, so that the titanium atoms can combine with the aluminum atoms to form an intermetallic compound layer.

[0005] FIG. 1 is a drawing illustrating a diffusion heat treatment process for manufacturing an aluminum alloy plate according to one embodiment of the present disclosure.

[0006] FIG. 2a is an exemplary diagram of mutual diffusion during a diffusion heat treatment process for manufacturing an aluminum alloy plate according to one embodiment of the present disclosure.

[0007] FIG. 2b is a drawing showing an example of the arrangement of an intermetallic compound after a diffusion heat treatment process for manufacturing an aluminum alloy plate according to one embodiment of the present disclosure is completed.

[0008] FIGS. 3A to 3C are drawings illustrating changes in an intermetallic compound layer during a diffusion heat treatment process for manufacturing an aluminum alloy plate according to one embodiment of the present disclosure.

[0009] FIG. 4 is a drawing illustrating a processing procedure for manufacturing an aluminum alloy plate according to one embodiment of the present disclosure.

[0010] FIG. 5a exemplarily shows the mutual diffusion of aluminum atoms (Al) and titanium atoms (Ti) during a diffusion heat treatment process for manufacturing an aluminum alloy plate according to one embodiment of the present disclosure.

[0011] FIG. 5b shows the structure of an aluminum alloy plate manufactured by diffusion heat treatment according to one embodiment of the present disclosure.

[0012] In connection with the description of the drawings, the same or similar reference numerals may be used for identical or similar components.

[0013] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings so that those skilled in the art can easily implement the present disclosure. However, the present disclosure may be implemented in various different forms and is not limited to the embodiments described herein. In connection with the description of the drawings, the same or similar reference numerals may be used for identical or similar components. Furthermore, in the drawings and related descriptions, descriptions of well-known functions and configurations may be omitted for clarity and conciseness.

[0014] One embodiment of the present disclosure can provide an aluminum alloy plate having an intermetallic compound layer formed therein by diffusion heat treating a layered structure in which an aluminum plate is laminated on the surface of a titanium plate having a relatively thin thickness.

[0015] According to one embodiment of the present disclosure, an aluminum alloy plate having a high ductility aluminum layer exposed to the outside can increase resistance to external force by primarily reducing impact by external force.

[0016] The technical problems to be achieved in the present disclosure are not limited to the technical problems mentioned above, and other technical problems not mentioned above can be derived from the exemplary embodiments of the present disclosure by a person having ordinary knowledge in the relevant technical field.

[0017] The effects that can be achieved by the exemplary embodiments of the present disclosure can be clearly derived and understood by those skilled in the art to which the exemplary embodiments of the present disclosure pertain, from the following description. In other words, unintended effects resulting from the implementation of the exemplary embodiments of the present disclosure can also be derived by those skilled in the art from the exemplary embodiments of the present disclosure.

[0018] FIG. 1 is a drawing illustrating a diffusion heat treatment process in a manufacturing system (100) for manufacturing an aluminum alloy plate according to one embodiment of the present disclosure.

[0019] Referring to FIG. 1, a diffusion heat treatment device (110) may be set to a predetermined temperature and / or time required for diffusion heat treatment of a layered structure (120). The predetermined temperature may be a temperature to be used for diffusion heat treatment. The predetermined temperature may be controlled to an optimal temperature as the time for diffusion heat treatment elapses. The time required may be the total time for diffusion heat treatment. The time required may be a time required for all titanium atoms (Ti) of at least one titanium plate (125) included in the layered structure (120) to combine with aluminum atoms (Al) through diffusion to form an intermetallic compound having a predetermined crystal structure (e.g., TiAl, Ti2Al, Ti3Al, TiAl2, TiAl3). The temperature range for the diffusion heat treatment may be, for example, 550 to 600 degrees. In this case, the temperature for the diffusion heat treatment may be determined between 550 and 600 degrees. The time required for the above diffusion heat treatment may be, for example, 24 to 120 hours. In this case, the time required for the above diffusion heat treatment may be determined between 24 and 120 hours.

[0020] In the diffusion heat treatment device (110), a predetermined temperature and / or required time can be set, for example, in consideration of the number of aluminum plates (121, 123) included in the layered structure (120). In the diffusion heat treatment device (110), a predetermined temperature and / or required time can be set, for example, in consideration of the number of titanium plates (125) included in the layered structure (120). In the diffusion heat treatment device (110), a predetermined temperature and / or required time can be set, for example, in consideration of the number of aluminum plates (121, 123) and the number of titanium plates (125) included in the layered structure (120). In the diffusion heat treatment device (110), a predetermined temperature and / or required time can be set, for example, in consideration of the thickness of the aluminum plates (121, 123) included in the layered structure (120). In the diffusion heat treatment device (110), a predetermined temperature and / or required time can be set, for example, in consideration of the thickness of the titanium plate (125) included in the layered structure (120). In the diffusion heat treatment device (110), a predetermined temperature and / or required time can be set, for example, in consideration of the thickness of the aluminum plates (121, 123) included in the layered structure (120) and the thickness of the titanium plate (125). In the diffusion heat treatment device (110), a predetermined temperature and / or required time can be set, for example, in consideration of the number and thickness of the aluminum plates (121, 123) included in the layered structure (120). In the diffusion heat treatment device (110), a predetermined temperature and / or required time can be set, for example, in consideration of the number and thickness of the titanium plates (125) included in the layered structure (120).In the above diffusion heat treatment device (110), a predetermined temperature and / or required time can be set by considering, for example, the number and thickness of aluminum plates (121, 123) included in the layered structure (120) and the number and thickness of titanium plates (125).

[0021] According to one example, a layered structure (120) supplied to a diffusion heat treatment device (110) as a target for diffusion heat treatment may have a multilayered structure in which at least one aluminum plate (121, 123) and at least one titanium plate (125) are laminated. The layered structure (120) may be an object hot-welded by applying a predetermined amount of heat and pressure to the laminated at least one aluminum plate (121, 123) and at least one titanium plate (125). The layered structure (120) may have, for example, a structure in which one titanium plate (125) is sandwiched between two aluminum plates (121, 123). The titanium plate (125) sandwiched between the aluminum plates (121, 123) may have a relatively thin thickness compared to the aluminum plates (121, 123). That is, one aluminum plate (121, 123) and one titanium plate (125) may have a predetermined thickness ratio. For example, the thickness ratio may be 20:1. below defines an example of the thickness relationship (thickness ratio) of one aluminum plate (121, 123) and one titanium plate (125).

[0022] Aluminum plate thickness (mm)Titanium plate thickness (mm)2.00.11.80.091.60.081.40.071.20.061.00.05

[0023] In the above , the thickness of the titanium plate (125) is limited to 0.1 millimeter (mm) or less. Limiting the thickness of the titanium plate (125) to 0.1 mm or less may mean limiting the thickness of the aluminum plate (121, 123) to 2.0 mm or less. However, even if the thickness of the titanium plate (125) is limited to 0.1 mm or less, it does not necessarily mean that the thickness of the aluminum plate (121, 123) must be limited to 2.0 mm or less. For example, according to the above , when the thickness of the titanium plate (125) is 0.1 mm, the thickness of the aluminum plate (121, 123) may be 2.0 mm or more. For example, when the thickness of the titanium plate (125) is 0.05 mm, the thickness of the aluminum plate (121, 123) may be 1.0 mm or more.

[0024] The above proposes the thickness of one aluminum plate (121, 123) and the thickness of one titanium plate (125) so that the thickness ratio of the aluminum plates (121, 123) and the titanium plates (125) in the layered structure (120) is 20:1. The thickness of the aluminum plate (121, 123) or the thickness of the titanium plate (125) can be determined, for example, by considering the thickness of the aluminum alloy plate (130) to be manufactured. The thickness of the aluminum plate (121, 123) or the thickness of the titanium plate (125) can be determined, for example, by considering the number of aluminum plates (121, 123) and / or the number of titanium plates (125) constituting the layered structure (120). The thickness of the aluminum plate (121, 123) or the thickness of the titanium plate (125) can be determined, for example, by considering the thickness of the aluminum alloy plate (130) to be manufactured and the number of aluminum plates (121, 123) constituting the layered structure (120). The thickness of the aluminum plate (121, 123) or the thickness of the titanium plate (125) can be determined, for example, by considering the thickness of the aluminum alloy plate (130) to be manufactured and the number of titanium plates (125) constituting the layered structure (120). The thickness of the aluminum plate (121, 123) or the thickness of the titanium plate (125) can be determined, for example, by considering the thickness of the aluminum alloy plate (130) to be manufactured, the number of aluminum plates (121, 123) constituting the layered structure (120), and the number of titanium plates (125).For example, in order to increase the thickness of the aluminum alloy plate (130) to be manufactured, the number of aluminum plates (121, 123) and / or the number of titanium plates (125) must inevitably be increased, or the thickness of the aluminum plates (121, 123) and / or the thickness of the titanium plates (125) must be increased. Conversely, for example, in order to reduce the thickness of the aluminum alloy plate (130) to be manufactured, the number of aluminum plates (121, 123) and / or the number of titanium plates (125) must inevitably be reduced, or the thickness of the aluminum plates (121, 123) and / or the thickness of the titanium plates (125) must be reduced. For example, if the thickness of the aluminum alloy plate (130) to be manufactured has been determined, the number of aluminum plates (121, 123) and / or the number of titanium plates (125) constituting the layered structure (120) can be determined. For example, if the thickness of the aluminum alloy plate (130) to be manufactured has been determined, the thickness of the aluminum plates (121, 123) and / or the thickness of the titanium plates (125) can be determined by considering the number of aluminum plates (121, 123) and / or the number of titanium plates (125) constituting the layered structure (120).

[0025] For example, a plurality of aluminum plates (121, 123) constituting the layered structure (120) may have substantially the same thickness. For example, a plurality of aluminum plates (121, 123) constituting the layered structure (120) may have different thicknesses, respectively. For example, a plurality of titanium plates (125) constituting the layered structure (120) may have substantially the same thickness. For example, a plurality of titanium plates (125) constituting the layered structure (120) may have different thicknesses, respectively. For example, in the layered structure (120), a plurality of aluminum plates (121, 123) may have substantially the same thickness, and a plurality of titanium plates (125) may have different thicknesses, respectively. For example, in the layered structure (120), a plurality of aluminum plates (121, 123) may have different thicknesses, and a plurality of titanium plates (125) may have substantially the same thickness.

[0026] According to one embodiment, at least one aluminum plate (121, 123) constituting the layered structure (120) can be produced by recycling a recycled aluminum alloy such as waste aluminum scrap or waste aluminum chips. The recycled aluminum alloy used to produce the at least one aluminum plate (121, 123) constituting the layered structure (120) can have a chemical composition consisting of, for example, 3.0 to 6.0% of zinc (Zn), 0.33 to 2.0% of magnesium (Mg), 0.04 to 0.5% of copper (Cu), and the remainder being aluminum (Al). The recycled aluminum alloy may also contain, for example, silicon (Si), iron (Fe), titanium (Ti), and manganese (Mn) as impurities. At least one titanium plate (125) constituting the layered structure (120) may have a chemical composition ratio of, for example, nitrogen (N) of about 0.03%, carbon (C) of about 0.08%, hydrogen (H) of about 0.013%, iron (Fe) of about 0.20%, oxygen (O) of about 0.15%, and the remainder being titanium (Ti).

[0027] As described above, when recycling recycled aluminum, even without adding reinforcing elements to strengthen the aluminum alloy, an aluminum alloy sheet having fewer surface defects and high strength can be produced by utilizing dissimilar metals (e.g., titanium) contained in the recycled aluminum. For example, when improving strength by utilizing scrap aluminum and pure aluminum, reinforcing elements had to be added. In this case, in order to increase the strength during the aging heat treatment process, the amount of reinforcing elements added must be increased, which may increase surface defects caused by precipitates and / or impurities. In contrast, when producing an aluminum alloy sheet by recycling recycled aluminum, reinforcing elements can be omitted or the amount added can be reduced, thereby reducing surface defects in the aluminum alloy sheet. In addition, when producing an aluminum alloy sheet by recycling recycled aluminum, a TiAlMg intermetallic compound can be generated due to the magnesium (Mg) contained in the recycled aluminum, thereby enabling further improvement in the strength of the aluminum alloy sheet.

[0028] The reason why the aluminum plates (121, 123) have a relatively thicker thickness than the titanium plate (125) is to take into account the fact that the speed at which each material diffuses into another material is different. For example, when the layered structure (120) is subjected to diffusion heat treatment, the titanium atoms of the titanium plate (125) and the aluminum atoms of the aluminum plates (121, 123) may diffuse into each other. At this time, the speed at which the aluminum atoms (Al) diffuse into the matrix within the titanium plate (125) (D_Al) (in Ti) ) is the rate at which titanium atoms (Ti) diffuse into the matrix within the aluminum plate (121, 123) (D_Ti (in Al)) is known to be about 10 times faster than that of the titanium plate (125). Therefore, in order to ensure that aluminum or aluminum alloy remains on the outer surface of the aluminum alloy plate (130) obtained by diffusion heat treatment, it is preferable that the aluminum plate (121, 123) have a relatively thicker thickness than the titanium plate (125).

[0029] In one example, the diffusion heat treatment device (110) can perform a diffusion heat treatment operation on the layered structure (120). The diffusion heat treatment in the diffusion heat treatment device (110) causes aluminum atoms (Al) and titanium atoms (Ti) to mutually diffuse and bond within the layered structure (120). For example, the bonding of aluminum atoms (Al) and titanium atoms (Ti) can generate an intermetallic compound layer (135) having a predetermined crystal structure (e.g., TiAl, Ti2Al, Ti3Al, TiAl2, TiAl3) in the layered structure (120). For example, the diffusion heat treatment device (110) can obtain an aluminum alloy (130) including the intermetallic compound layer (135) by performing the diffusion heat treatment for a preset required time. In the aluminum alloy (130), only an intermetallic compound (TiAl / Ti3Al) layer (135) and aluminum layers (131, 133) may be present without a titanium plate (125). The aluminum alloy (130) may have a multilayer structure in which one or more aluminum layers (131, 133) and one or more intermetallic compound layers (135) are laminated. The reason why aluminum or an aluminum alloy remains on the outer surface of the aluminum alloy plate (130) is for the convenience of surface treatment such as anodizing of aluminum. In the one or more intermetallic compound layers (135), the thickness of the central axis (e.g., substantially near the center of the intermetallic compound layer) and the thickness of the edge (e.g., substantially near both sides of the intermetallic compound) may be different. The one or more intermetallic compound layers (135) may be, for example, a titanium aluminide (TiAl) layer.

[0030] According to the above, in the aluminum alloy plate (130) made by the diffusion heat treatment device (110), in response to the diffusion heat treatment, the titanium atoms of the titanium plate (125) and the aluminum atoms of the aluminum plate (121, 123) can diffuse mutually based on the bonding boundary between the aluminum plate (121, 123) and the titanium plate (125), so that an intermetallic compound layer (261, 263) can be formed by bonding all the titanium atoms of the titanium plate (125) and the aluminum atoms.

[0031] In one example, at the joint boundary between an aluminum plate (121, 123) (e.g., an aluminum plate (511, 513, 515) of FIG. 5a or an aluminum plate (551, 553, 555) of FIG. 5b) and a titanium plate (125) (e.g., a titanium plate (521, 523) of FIG. 5a or a titanium plate (561, 563) of FIG. 5b), unevenness (e.g., unevennesses (571, 572, 573, 574, 575, 576, 577, 578, 579) of FIG. 5b)) may be generated. The above-mentioned irregularities (571, 572, 573, 574, 575, 576, 577, 578, 579) are formed because, during diffusion heat treatment, titanium atoms constituting the titanium plate (e.g., titanium plate (521, 523) of FIG. 5a) are closer to the grain boundaries (e.g., grain boundaries (b1, b2, b3, b4, b5, b6, b7, b8, b9, b of FIG. 5a) than within the grains of the aluminum plate (e.g., aluminum plate (511, 513, 515) of FIG. 5a). 10 , b 11 )) is fast. For example, in a metal material, the grain boundaries (e.g., grain boundaries (b1, b2, b3, b4, b5, b6, b7, b8, b9, b in Fig. 5a) 10 , b 11)) may correspond to a vacant lattice point where the metal atoms are empty due to the different arrangement directions of the metal atoms. The above crystal grain boundaries (b1, b2, b3, b4, b5, b6, b7, b8, b9, b 10 , b 11 ) can facilitate the diffusion of heterogeneous metal atoms.

[0032] The above aluminum alloy plate (130) can be processed and used as an exterior material for an electronic device.

[0033] FIG. 5a exemplarily shows the mutual diffusion of aluminum atoms (Al) and titanium atoms (Ti) during a diffusion heat treatment process for manufacturing an aluminum alloy plate according to one embodiment of the present disclosure.

[0034] Referring to FIG. 5a, a hot-welded layered structure (e.g., a laminated structure (120) of FIG. 1) may be subjected to a diffusion heat treatment to which at least one of a predetermined temperature or a predetermined holding time is applied. By the diffusion heat treatment, in the layered structure (120), aluminum atoms (Al) of aluminum plates (511, 513, 515) may diffuse (531) into titanium plates (521, 523). By the diffusion heat treatment, in the layered structure (120), titanium atoms (Ti) of titanium plates (521, 523) may diffuse (541) into aluminum plates (511, 513, 515). In the above layered structure (120), the aluminum plates (511, 513, 515) have grain boundaries (b1, b2, b3, b4, b5, b6, b7, b8, b9, b 10 , b 11 ) may include the crystal grain boundaries (b1, b2, b3, b4, b5, b6, b7, b8, b9, b 10 , b 11) may correspond to a vacant lattice point where aluminum atoms are empty due to the different arrangement directions of aluminum atoms in the aluminum plates (511, 513, 515). When the titanium atoms (Ti) of the titanium plates (521, 523) are mutually diffused due to the diffusion heat treatment, the titanium atoms (Ti) of the titanium plates (521, 523) are more abundant at the grain boundaries (b1, b2, b3, b4, b5, b6, b7, b8, b9, b) than within the grains of the aluminum plates (511, 513, 515). 10 , b 11 ) can spread relatively quickly.

[0035] FIG. 5b shows the structure of an aluminum alloy plate (e.g., aluminum alloy plate (130) of FIG. 1) manufactured by diffusion heat treatment according to one embodiment of the present disclosure.

[0036] Referring to FIG. 5b, when a diffusion heat treatment process is completed by applying at least one of a predetermined temperature or a predetermined holding time to a hot-welded layered structure (e.g., a layered structure (120) of FIG. 1), an aluminum alloy plate (130) can be obtained. The aluminum alloy plate (130) can have a structure in which an intermetallic compound layer (561, 563) is formed between remaining aluminum plates (551, 553, 555). One or more unevennesses (571, 572, 573, 574, 575, 576, 577, 578, 579) can be formed at the bonding boundary between the remaining aluminum plates (551, 553, 555) and the intermetallic compound layer (561, 563). For example, the one or more protrusions (571, 572, 573, 574, 575, 576, 577, 578, 579) may have a sawtooth-like shape. The one or more protrusions (571, 572, 573, 574, 575, 576, 577, 578, 579) may be included in the aluminum plate (551, 553, 555) at a grain boundary (e.g., grain boundaries (b1, b2, b3, b4, b5, b6, b7, b8, b9, b in FIG. 5a). 10 , b 11 )) can be made along the grain boundaries (b1, b2, b3, b4, b5, b6, b7, b8, b9, b 10 , b 11 ) is made along the grain boundaries (b1, b2, b3, b4, b5, b6, b7, b8, b9, b) during diffusion heat treatment. 10 , b 11 ) because the rate at which titanium atoms (Ti) diffuse into the crystal is faster than in other areas (e.g., within the grains).

[0037] FIG. 2a is an exemplary diagram of mutual diffusion during a diffusion heat treatment process for manufacturing an aluminum alloy plate according to one embodiment of the present disclosure.

[0038] Referring to FIG. 2a, the layered structure (200a) before diffusion heat treatment may have a structure in which at least one aluminum plate (211, 213, 215) and at least one titanium plate (221, 223) are arranged based on the bonding boundary. For example, the first titanium plate (221) may be arranged between the first aluminum plate (211) and the second aluminum plate (213). For example, the second titanium plate (223) may be arranged between the second aluminum plate (213) and the third aluminum plate (215). The illustrated layered structure (200a) has a five-layer structure, but may also have a three-layer structure or a seven-layer or more structure.

[0039] In the layered structure (200a), the aluminum plates (211, 213, 215) may have a relatively thicker thickness than the titanium plates (221, 223). This is in consideration of the fact that the speed at which each material diffuses into another material is different. The thickness of the titanium plates (221, 223) may be limited to, for example, 0.1 millimeter (mm). For example, when the layered structure (200a) is subjected to diffusion heat treatment, aluminum atoms of the aluminum plates (211, 213, 215) may diffuse (231) in a first direction (e.g., a direction from the first aluminum plate (211) to the first titanium plate (221)) and a second direction (e.g., a direction from the second aluminum plate (213) to the first titanium plate (221). For example, when the layered structure (200a) is subjected to diffusion heat treatment, titanium atoms of titanium plates (221, 223) can diffuse (241) in a third direction (e.g., a direction from the first titanium plate (221) to the first aluminum plate (211)) and a fourth direction (e.g., a direction from the first titanium plate (221) to the second aluminum plate (213).

[0040] The speed (D_Al) at which the aluminum atoms (Al) diffuse (231) into the matrix within the titanium plate (221, 223) (in Ti) ) is the rate at which the titanium atoms (Ti) diffuse into the matrix within the aluminum plate (211, 213, 215) (D_Ti (in Al)) is known to be about 10 times faster than that of titanium plates (221, 223). Therefore, in order to have aluminum or an aluminum alloy remain on the outer surface of the aluminum alloy plate (200b) obtained by diffusion heat treatment, it may be desirable to have the aluminum plates (211, 213, 215) have a relatively thicker thickness than the titanium plates (221, 223). The reason for having aluminum or an aluminum alloy remain on the outer surface of the aluminum alloy plate (200b) is that surface treatment such as anodizing of aluminum or an aluminum alloy is easy.

[0041] At least one of the temperature or holding time for the diffusion heat treatment may be determined, for example, by the thickness of the titanium plate (221, 223) in the layered structure (220a). At least one of the temperature or holding time for the diffusion heat treatment may be determined, for example, by the thickness of the aluminum plate (211, 213, 215) in the layered structure (220a). The thickness of the titanium plate (221, 223) may decrease or increase in proportion to the thickness of the aluminum plate (211, 213, 215). The thickness of the intermetallic compound layer (261, 263) may increase or decrease in proportion to at least one of the temperature or holding time for the diffusion heat treatment. The ratio of the thickness of the aluminum plate (211, 213, 215) to the thickness of the titanium plate (221, 223) may be, for example, 20:1.

[0042] The number or thickness of the aluminum plates (211, 213, 215) that constitute the layered structure (220a) and the number or thickness of the titanium plates (221, 223) can be determined by considering the thickness of the aluminum alloy plate (220b).

[0043] At least one of the temperature or holding time for the above diffusion heat treatment may be determined, for example, by the number of titanium plates (221, 223) included in the layered structure (220a). At least one of the temperature or holding time for the above diffusion heat treatment may be determined, for example, by the number of aluminum plates (211, 213, 215) included in the layered structure (200a).

[0044] FIG. 2b is a drawing showing an example of the arrangement of an intermetallic compound after a diffusion heat treatment process for manufacturing an aluminum alloy plate according to one embodiment of the present disclosure is completed.

[0045] Referring to FIG. 2b, the aluminum alloy plate (200b) produced by completing the diffusion heat treatment process may have a multilayer structure in which one or more aluminum layers (251, 253, 255) and one or more intermetallic compound layers (261, 263) are laminated. A titanium layer does not exist in the aluminum alloy plate (200b). That is, the aluminum alloy plate (200b) may not have any titanium plates (e.g., titanium plates (221, 223) in FIG. 2a) remaining, and only intermetallic compound (TiAl / Ti3Al) layers (261, 263) and aluminum layers (251, 253, 255) may exist entirely.

[0046] In one example, one or more intermetallic compound layers (261, 263) may be formed by interdiffusion of titanium atoms and aluminum atoms (e.g., diffusion (231, 241) in FIG. 2a) at a bonding boundary between an aluminum plate (e.g., an aluminum plate (211, 213, 215) in FIG. 2a) and a titanium plate (e.g., a titanium plate (221, 223) in FIG. 2a) in response to diffusion heat treatment, such that all titanium atoms are bonded with aluminum atoms, thereby forming an intermetallic compound. The intermetallic compound may have, for example, a predetermined crystal structure (e.g., TiAl, Ti2Al, Ti3Al, TiAl2, TiAl3).

[0047] The aluminum layer (251, 255) exposed to the outside of the aluminum alloy plate (200b) is a highly ductile layer and can primarily reduce impact caused by external force. The aluminum alloy plate (200b) having an outer surface made of the aluminum layer (251, 255) can have higher resistance to external force and thus enhance the impact absorption effect compared to a plate made only of an intermetallic compound. In addition, the aluminum layer (251, 255) corresponding to the outer surface of the aluminum alloy plate (200b) can block microcracks generated on the outside due to repeated fatigue stress from propagating.

[0048] FIGS. 3A to 3C are drawings illustrating changes in an intermetallic compound layer during a diffusion heat treatment process for manufacturing an aluminum alloy plate according to one embodiment of the present disclosure.

[0049] Referring to FIG. 3a, a layered structure (e.g., a layered structure (200a) of FIG. 2a) before diffusion heat treatment may have a structure in which at least one aluminum plate (310a) (e.g., aluminum plates (211, 213, 215) of FIG. 2a) and at least one titanium plate (320a) (e.g., titanium plates (221, 223) of FIG. 2a) are arranged based on a bonding boundary. The at least one titanium plate (320a) may be made of pure titanium (unalloyed titanium or pure titanium). The pure titanium may be, for example, one of Ti-Grade 1 (Gr1), Ti-Gr2, Ti-Gr3, or Ti-Gr4.

[0050] The above at least one aluminum plate (310a) can be produced by recycling a recycled aluminum alloy (Recycled-Al), such as waste aluminum scrap or waste aluminum chips. The recycled aluminum alloy can have a chemical composition consisting of 3.0 to 6.0% zinc (Zn), 0.33 to 2.0% magnesium (Mg), 0.04 to 0.5% copper (Cu), and the remainder aluminum (Al). The recycled aluminum alloy may also contain, for example, silicon (Si), iron (Fe), titanium (Ti), and manganese (Mn) as impurities.

[0051] Referring to FIG. 3b, when diffusion heat treatment is performed at a predetermined temperature (e.g., 550°C) for a predetermined period of time (e.g., 24 hours), diffusion in both directions (e.g., first to third direction diffusion (231, 241) in FIG. 2a) can occur based on the bonding boundary between at least one aluminum plate (310b) and at least one titanium plate (320b) within the layered structure (200a). The diffusion in both directions can expand the area of ​​the intermetallic compound layer (330b) in both directions from near the bonding boundary of the hot-welded layered structure (200a). The intermetallic compound layer (330b) can be made of a material (TiAl, Ti3Al) composed of aluminum and titanium atoms.

[0052] Referring to FIG. 3c, when diffusion heat treatment is performed at a predetermined temperature (e.g., 550° C.) for a predetermined time (e.g., 48 hours), the area of ​​the intermetallic compound layer (330c) can be expanded within the layered structure (200a).

[0053] As described above, the area of ​​the intermetallic compound layer (330c) in the layered structure (200a) can gradually increase in proportion to the temperature and / or time required for diffusion heat treatment.

[0054] below defines the thickness (unit: ㎛) of the intermetallic compound layer (330b, 330c) that can be formed depending on the temperature and time required for diffusion heat treatment.

[0055]

[0056] Referring to the above , the thickness of the intermetallic compound (TiAl / Ti3Al) layer (330b, 330c) can increase in proportion to the temperature and time required for diffusion heat treatment.

[0057] For example, when the temperature is 550°C and the time required is 24 hours (hr) as the conditions for diffusion heat treatment, the thickness of the intermetallic compound layer (330b, 330c) formed by the diffusion heat treatment may be about 10 μm. When the temperature is maintained at 550°C and the time required is increased to 48 hours (hr) as the conditions for the diffusion heat treatment, the thickness of the intermetallic compound layer (330b, 330c) formed by the diffusion heat treatment may be about 20 μm. That is, when the temperature is maintained and the time required is increased, the thickness of the intermetallic compound layer (330b, 330c) increases as the time required increases. For example, the thickness of the intermetallic compound layer (330b, 330c) may increase by 10 μm for every 24 hours (hr) that the time required increases.

[0058] For example, when the temperature is 580°C and the time required for diffusion heat treatment is 24 hours (hr), the thickness of the intermetallic compound layer (330b, 330c) formed by the diffusion heat treatment may be approximately 50 μm. When the time required for the diffusion heat treatment is maintained at 24 hours (hr) and the temperature is increased to 600°C, the thickness of the intermetallic compound layer (330b, 330c) formed by the diffusion heat treatment may increase at a rate of 200 μm. That is, it can be confirmed that the thickness of the intermetallic compound layer (330b, 330c) increases as the temperature increases during the diffusion heat treatment because the diffusion speed of atoms increases. However, at a critical temperature (e.g., 620°C), the diffusion distance increases, so the thickness of the intermetallic compound layer (330b, 330c) tends to increase relatively significantly. However, since the multilayer structure is not maintained and deformation may occur because it is close to the melting point of the aluminum alloy, it may be desirable to perform the diffusion heat treatment at a temperature (e.g., 600°C) lower than the critical temperature (e.g., 620°C).

[0059] FIG. 4 is a drawing illustrating a work processing procedure for manufacturing an aluminum alloy sheet in a manufacturing system for manufacturing an aluminum alloy sheet according to one embodiment of the present disclosure.

[0060] Referring to FIG. 4, the manufacturing system can produce an aluminum plate for manufacturing an aluminum alloy sheet (operations 410 and 420). The manufacturing system can perform operations 410 and 420 only when it is intended to recycle recycled aluminum, such as waste aluminum scrap or waste aluminum chips.

[0061] For example, the manufacturing system may, in operation 410, input materials for manufacturing an aluminum plate and perform a melting operation to melt the input materials. The materials input for manufacturing the aluminum plate may be, for example, recycled aluminum such as waste aluminum scrap or waste aluminum chips, or pure aluminum.

[0062] In order to use the waste aluminum scrap or waste aluminum chips as recycled aluminum, a process of classifying them based on additive elements (e.g., Cu, Mn, Mg, Si, Zn, etc.) may be performed first. This is because the type of additive element used in the waste aluminum scrap or waste aluminum chips can be determined depending on the intended use. For example, Si or Mg may be an additive element for improving castability, and Cu may be an additive element for improving strength. An aluminum alloy in which the Si or Mg is used as an additive element may be classified as an Al-Si alloy or an Al-Mg alloy. An aluminum alloy in which the Cu is used as an additive element may be classified as an Al-Cu-Si alloy. The aluminum alloy classified based on the additive elements must be diluted with a certain amount of pure aluminum through a melting operation to adjust the purity that can obtain the ability for each intended use. The pure aluminum may be input in an amount such that the purity of the recycled aluminum can be adjusted to 80% to 90%, for example.

[0063] The above manufacturing system can perform a compression molding operation on a molten material of recycled aluminum and pure aluminum (operation 420). The compression molding operation can perform a task to solidify the molten material into a predetermined shape (e.g., a plate). The manufacturing system can produce an aluminum plate to be used in a layered structure through the compression molding operation.

[0064] The manufacturing system (100) can perform a hot welding operation on a layered structure using a predetermined heat and / or pressure in operation 430. At least one aluminum plate and at least one titanium plate included in the layered structure can be joined by the hot welding operation. The manufacturing system (100) can produce a hot-welded layered structure (e.g., the layered structure (200a) of FIG. 2A) by the hot welding operation. The layered structure (200a) can have a structure in which, for example, at least one aluminum plate (e.g., the aluminum plates (211, 213, 215) of FIG. 2A) and at least one titanium plate (e.g., the titanium plates (221, 223) of FIG. 2A) are arranged based on a joining boundary (see FIG. 2A).

[0065] The above manufacturing system (100) can perform a diffusion heat treatment operation on the hot-welded layered structure (200a) in operation 440. The hot-welded layered structure (200a) can have a structure in which at least one aluminum plate containing aluminum atoms (e.g., aluminum plates (211, 213, 215) of FIG. 2a) and at least one titanium plate containing titanium atoms (e.g., titanium plates (221, 223) of FIG. 2a) are hot-welded.

[0066] In one example, the diffusion heat treatment operation in the manufacturing system (100) causes aluminum atoms (Al) and titanium atoms (Ti) to mutually diffuse and bond within the layered structure (200a). For example, the bonding of aluminum atoms (Al) and titanium atoms (Ti) can generate an intermetallic compound layer (e.g., the intermetallic compound layers (261, 263) of FIG. 2b) having a predetermined crystal structure (e.g., TiAl, Ti2Al, Ti3Al, TiAl2, TiAl3) in the layered structure (200a). For example, the manufacturing system (100) can obtain an aluminum alloy plate (e.g., the aluminum alloy plate (200b) of FIG. 2b) including the intermetallic compound layer (261, 263) by performing the diffusion heat treatment for a preset required time. In the above aluminum alloy plate (200b), only intermetallic compound (TiAl / Ti3Al) layers (261, 263) and aluminum layers (e.g., aluminum layers (251, 253, 255) of FIG. 2b) may be present without any titanium plates (221, 223) remaining. The aluminum alloy plate (200b) may have a multilayer structure in which one or more aluminum layers (251, 253, 255) and one or more intermetallic compound layers (261, 263) are laminated.

[0067] According to one example, the manufacturing system (100) can diffusion heat treat a layered structure (200a) made by hot welding at a predetermined temperature (e.g., 550 to 600° C.). Through the diffusion heat treatment, an intermetallic compound having a crystal structure such as TiAl, Ti2Al, Ti3Al, TiAl2, or TiAl3 can be generated within the layered structure (200a). The intermetallic compound can form an intermetallic compound layer (261, 263) within the aluminum alloy plate (200b). If the diffusion heat treatment operation continues for a predetermined period of time, no more titanium plates (221, 223), i.e., no titanium layer, are present within the aluminum alloy plate (200b).

[0068] The manufacturing system (100) above can complete the manufacturing of an aluminum alloy plate at operation 450. The aluminum alloy plate may have lower mechanical properties of aluminum and titanium compared to the layered structure before diffusion heat treatment, but may have higher resistance to plastic deformation due to external force due to the intermetallic compound (TiAl / Ti3Al) layers (261, 263). The increased resistance to plastic deformation may result in improved mechanical properties (yield strength). In addition, even if an external force is applied to an aluminum layer exposed to the outside of the aluminum alloy plate (e.g., the aluminum layer (251, 255) of FIG. 2b), the primary impact reduction effect is achieved in the highly ductile layer, so that the resistance to external force is higher than when the aluminum alloy plate is composed only of an intermetallic compound, thereby enhancing the impact absorption effect. In other words, it is expected that the propagation of microcracks generated externally due to repeated fatigue stress can be blocked by the multilayer structure.

[0069] below compares the mechanical properties of aluminum, titanium, and intermetallic compounds by type.

[0070] Regenerated AlTi Gr1Ti Gr2Ti Gr3Ti Gr4Ti3AlTiAl Hardness (Hv) 50 130 160 200 230 Yield strength (MPa) 24 12 76 37 9 48 3700~990 350~750 Room temperature elongation (%) 27 23 18 152~81~4

[0071] Referring to the above , the aluminum alloy plate having a multilayer structure can have a unique role for each layer. For example, the aluminum layers (251, 255) constituting the surface of the aluminum alloy plate can facilitate plastic deformation due to external force and / or damage buffering due to external force, and surface processing or treatment. For example, the intermetallic compound layers (261, 263) constituting the interior of the aluminum alloy plate can enhance strength and / or resistance to bending deformation.

[0072] According to one embodiment of the present disclosure, an aluminum alloy plate (130) can be manufactured by diffusion heat treating a layered structure (120) in which an aluminum plate (211, 213, 215) and a titanium plate (221, 223) are hot-welded.

[0073] According to one embodiment of the present disclosure, in response to the diffusion heat treatment, in the aluminum alloy plate (130), titanium atoms of the titanium plate (221, 223) and aluminum atoms of the aluminum plate (211, 213, 215) can mutually diffuse (231, 241) based on the bonding boundary between the aluminum plate (211, 213, 215) and the titanium plate (221, 223), so that the titanium atoms can combine with the aluminum atoms to form an intermetallic compound layer (261, 263).

[0074] According to one embodiment of the present disclosure, at least one of the temperature or holding time for the diffusion heat treatment can be determined by the thickness of the titanium plate (221, 223) in the layered structure (120).

[0075] According to one embodiment of the present disclosure, the thickness of the titanium plate (221, 223) may be relatively thin compared to the aluminum plate (211, 213, 215).

[0076] According to one embodiment of the present disclosure, the thickness of the titanium plate (221, 223) may be limited to 0.1 millimeter (mm).

[0077] According to one embodiment of the present disclosure, the thickness of the titanium plate (221, 223) may be reduced or increased in proportion to the thickness of the aluminum plate (211, 213, 215).

[0078] According to one embodiment of the present disclosure, the ratio of the thickness of the aluminum plate (211, 213, 215) to the thickness of the titanium plate (221, 223) may be 20:1.

[0079] According to one embodiment of the present disclosure, at least one of the temperature or holding time for the diffusion heat treatment can be determined by the thickness of the aluminum plate (211, 213, 215) in the layered structure (120).

[0080] According to one embodiment of the present disclosure, at least one of the temperature or holding time for the diffusion heat treatment can be determined by the number of titanium plates (221, 223) included in the layered structure (120).

[0081] According to one embodiment of the present disclosure, at least one of the temperature or holding time for the diffusion heat treatment can be determined by the number of aluminum plates (211, 213, 215) included in the layered structure (120).

[0082] According to one embodiment of the present disclosure, the thickness of the intermetallic compound layer (261, 263) may increase or decrease in proportion to at least one of the temperature or holding time for the diffusion heat treatment.

[0083] According to one embodiment of the present disclosure, when the diffusion heat treatment is performed at a preset temperature and for a preset holding time, the titanium layer (221, 223) may not be present, and at least two aluminum layers (211, 213, 215) and at least one intermetallic compound layer (261, 263) may be present.

[0084] According to one embodiment of the present disclosure, an aluminum layer (251, 253, 255) having a predetermined thickness and remaining without bonding with titanium atoms can be formed inward from both surfaces.

[0085] According to one embodiment of the present disclosure, the aluminum plate (211, 213, 215) can be prepared by extruding a composite of melted waste aluminum scrap or waste aluminum chips and pure aluminum.

[0086] According to one embodiment of the present disclosure, the thickness of the intermetallic compound layer (261, 263) near the center axis and the edge may be different.

[0087] According to one embodiment of the present disclosure, the intermetallic compound layer (261, 263) may be a titanium aluminide (TiAl) layer.

[0088] According to one embodiment of the present disclosure, an aluminum alloy plate (130) can be used as an exterior material of an electronic device.

[0089] According to one embodiment of the present disclosure, the number or thickness of the aluminum plates (211, 213, 215) that constitute the layered structure (120) and the number or thickness of the titanium plates (221, 223) can be determined by considering the thickness of the aluminum alloy plate (130).

[0090] According to one embodiment of the present disclosure, the temperature range for the diffusion heat treatment may be 550 to 600 degrees, and the time range required for the diffusion heat treatment may be 24 to 120 hours.

[0091] According to one embodiment of the present disclosure, the bonding boundary between the remaining aluminum layer (251, 253, 255) and the intermetallic compound layer (561, 563) may have a sawtooth shape (571, 572, 573, 574, 575, 576, 577, 578, 579).

[0092] According to one embodiment of the present disclosure, the remaining aluminum layer (251, 253, 255) may be relatively soft and glossy compared to the intermetallic compound layer (261, 263).

[0093] Electronic devices according to the various embodiments disclosed in this document may take various forms. Electronic devices may include, for example, portable communication devices (e.g., smartphones), computer devices, portable multimedia devices, portable medical devices, cameras, wearable devices, or home appliances. Electronic devices according to the embodiments of this document are not limited to the aforementioned devices.

[0094] The various embodiments of this document and the terminology used therein are not intended to limit the technical features described in this document to specific embodiments, but should be understood to include various modifications, equivalents, or substitutes of the embodiments. In connection with the description of the drawings, similar reference numerals may be used for similar or related components. The singular form of a noun corresponding to an item may include one or more of the items, unless the context clearly indicates otherwise. In this document, each of the phrases "A or B", "at least one of A and B", "at least one of A or B", "A, B, or C", "at least one of A, B, and C", and "at least one of A, B, or C" can include any one of the items listed together in the corresponding phrase among those phrases, or all possible combinations thereof. Terms such as "first," "second," or "first" or "second" may be used merely to distinguish one component from another, and do not limit the components in any other respect (e.g., importance or order). When a component (e.g., a first component) is referred to as "coupled" or "connected" to another (e.g., a second component), with or without the terms "functionally" or "communicatively," it means that the component can be connected to the other component directly (e.g., wired), wirelessly, or through a third component.

[0095] The term "module" used in various embodiments of this document may include a unit implemented in hardware, software, or firmware, and may be used interchangeably with terms such as logic, logic block, component, or circuit. A module may be an integral component, or a minimum unit or part of such a component that performs one or more functions. For example, according to one embodiment, a module may be implemented in the form of an application-specific integrated circuit (ASIC).

[0096] Various embodiments of the present document may be implemented as software (e.g., a program (940)) including one or more instructions stored in a storage medium (e.g., an internal memory (936) or an external memory (938)) readable by a machine (e.g., an electronic device (901)). For example, a processor (e.g., a processor (920)) of the machine (e.g., an electronic device (901)) may call at least one instruction among the one or more instructions stored from the storage medium and execute it. This enables the machine to operate to perform at least one function according to the at least one called instruction. The one or more instructions may include code generated by a compiler or code executable by an interpreter. The machine-readable storage medium may be provided in the form of a non-transitory storage medium. Here, 'non-transitory' simply means that the storage medium is a tangible device and does not contain signals (e.g., electromagnetic waves), and the term does not distinguish between cases where data is stored semi-permanently or temporarily on the storage medium.

[0097] According to one embodiment, the method according to various embodiments disclosed in this document may be provided as included in a computer program product. The computer program product may be traded as a product between a seller and a buyer. The computer program product may be distributed in the form of a machine-readable storage medium (e.g., compact disc read-only memory (CD-ROM)), or may be distributed online (e.g., downloaded or uploaded) through an application store (e.g., Play Store™) or directly between two user devices (e.g., smart phones). In the case of online distribution, at least a portion of the computer program product may be temporarily stored or temporarily generated in a machine-readable storage medium, such as the memory of a manufacturer's server, an application store's server, or an intermediary server.

[0098] According to various embodiments, each component (e.g., a module or a program) of the above-described components may include one or more entities, and some of the entities may be separated and placed in other components. According to various embodiments, one or more components or operations of the aforementioned components may be omitted, or one or more other components or operations may be added. Alternatively or additionally, a plurality of components (e.g., a module or a program) may be integrated into a single component. In such a case, the integrated component may perform one or more functions of each of the plurality of components identically or similarly to those performed by the corresponding component among the plurality of components prior to the integration. According to various embodiments, the operations performed by a module, program, or other component may be executed sequentially, in parallel, iteratively, or heuristically, or one or more of the operations may be executed in a different order, omitted, or one or more other operations may be added.

Claims

1. In an aluminum alloy plate (130) manufactured by diffusion heat treating a layered structure (120) in which aluminum plates (211, 213, 215) and titanium plates (221, 223) are hot-welded, An aluminum alloy plate (130), wherein, in response to the diffusion heat treatment, titanium atoms of the titanium plate (221, 223) and aluminum atoms of the aluminum plate (211, 213, 215) are mutually diffused (231, 241) based on the bonding boundary between the aluminum plate (211, 213, 215) and the titanium plate (221, 223), so that the titanium atoms are bonded to the aluminum atoms to form an intermetallic compound layer (261, 263).

2. In paragraph 1, At least one of the temperature or holding time for the above diffusion heat treatment is determined by the thickness of the titanium plate (221, 223) in the layered structure (120), The thickness of the above titanium plate (221, 223) has a predetermined ratio to the thickness of the above aluminum plate (211, 213, 215). The thickness of the titanium plate (221, 223) is relatively thin compared to the aluminum plate (211, 213, 215), and the aluminum alloy plate (130).

3. In paragraph 1 or 2, An aluminum alloy plate (130) having a thickness of the titanium plate (221, 223) limited to 0.1 millimeter (mm).

4. In paragraph 1 or paragraph 3, An aluminum alloy plate (130) in which the ratio of the thickness of the aluminum plate (211, 213, 215) to the thickness of the titanium plate (221, 223) is 20:

1.

5. In paragraph 2 or paragraph 4, An aluminum alloy plate (130), wherein at least one of the temperature or holding time for the above diffusion heat treatment is determined by the thickness of the aluminum plate (211, 213, 215) in the layered structure (120).

6. In paragraph 1, An aluminum alloy plate (130), wherein at least one of the temperature or holding time for the above diffusion heat treatment is determined by the number of titanium plates (221, 223) included in the layered structure (120).

7. In paragraph 1, An aluminum alloy plate (130), wherein at least one of the temperature or holding time for the above diffusion heat treatment is determined by the number of aluminum plates (211, 213, 215) included in the layered structure (120).

8. In paragraph 1, An aluminum alloy plate (130), wherein the thickness of the intermetallic compound layer (261, 263) increases or decreases in proportion to at least one of the temperature or holding time for the diffusion heat treatment.

9. In paragraph 1, An aluminum alloy plate (130) in which, when the above diffusion heat treatment is performed at a preset temperature and for a preset holding time, no titanium layer (221, 223) exists, and at least two aluminum layers (211, 213, 215) and at least one intermetallic compound layer (261, 263) exist.

10. In paragraph 1, An aluminum alloy plate (130) prepared by extruding a composite material of melted pure aluminum and scrap aluminum or chips and waste aluminum to form the aluminum plate (211, 213, 215).

11. In paragraph 1, An aluminum alloy plate (130) having different thicknesses near the center axis and edges in the intermetallic compound layer (261, 263).

12. In paragraph 1, The intermetallic compound layer (261, 263) is a titanium aluminide (TiAl) layer, and is an aluminum alloy plate (130).

13. In any one of paragraphs 1 to 4, An aluminum alloy plate (130) in which the number or thickness of the aluminum plates (211, 213, 215) forming the layered structure (120) and the number or thickness of the titanium plates (221, 223) are determined by taking into account the thickness of the aluminum alloy plate (130).

14. In any one of paragraphs 1 to 4, The temperature range for the above diffusion heat treatment is 550 to 600 degrees, An aluminum alloy plate (130) having a time range of 24 to 120 hours for the above diffusion heat treatment.

15. In any one of paragraphs 1 to 5, In the above layered structure (120), the titanium atoms diffuse (241) into the aluminum plates (211, 213, 215) arranged on both sides of the titanium plates (221, 223), thereby forming the intermetallic compound layer (261, 263). The bonding boundary between the residual aluminum layer (551, 553, 555) and the intermetallic compound layer (561, 563) included in the aluminum alloy plate (130) has a sawtooth shape (571, 572, 573, 574, 575, 576, 577, 578, 579). An aluminum alloy plate (130) in which the residual aluminum layer (251, 253, 255) is relatively soft and glossy compared to the intermetallic compound layer (261, 263).

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