TWI695895B - Method of fabricating aluminum-magnesium-silicon alloy sheet with high bendability - Google Patents

Abstract

This invention is focused on a method of fabricating an aluminum-magnesium-silicon alloy sheet with high bendability. In this method, the aluminum slabs with a specific composition range were hot-rolled and cold-rolled into aluminum sheets by specific steps, followed by a necessary heat treatment. During the fabrication, an innovative two-step homogenization process was introduced on aluminum slabs to remove the harmful low-melting-point Mg ₂Si phase and further to spheroidize the irregular, hard Al ₁₅(Fe,Mn) ₃Si ₂phase. Moreover, a unique intermediate annealing process at high temperatures is also applied between a hot rolling step and a cold rolling step, so that the obtained aluminum-magnesium-silicon alloy sheets with randomized distribution of grain orientation show very excellent bendability, which do not cause microcracks during a bending process and still have a commercially acceptable post-baking yield strength (PBYS).

Description

Method for manufacturing high-bending aluminum magnesium silicon alloy sheet

The invention relates to a method for manufacturing an alloy sheet, in particular to a method for manufacturing an aluminum magnesium silicon alloy sheet with high bendability.

Al-Mg-Si alloy has the advantages of light weight, good formability and high strength after painting and baking. This kind of material has become the mainstream of lightweight vehicles in the world. However, after this material is stamped and formed into the outer and inner sheet parts of the hood, the outer sheet parts still need to be bent to cover the inner sheet parts. Although it is acceptable to have a rough surface at the bend, it should not have micro cracks. Because this will affect the safety of the above assembly. However, existing aluminum-magnesium-silicon alloys often produce micro-cracks at the bends.

Therefore, it is necessary to provide a high-bendability aluminum-magnesium-silicon alloy sheet to solve the problems in the conventional technology.

One object of the present invention is to provide a method for manufacturing a high-bendability aluminum magnesium silicon alloy sheet, which is to form aluminum sheets of a specific composition into aluminum sheets through specific hot rolling and cold rolling steps, and then apply necessary heat treatment ; In the meantime, through the innovative two-stage homogenization step to remove the harmful low-melting phase (Mg ₂ Si) in the aluminum embryo, and the irregular hard and brittle phase (Al ₁₅ (Fe,Mn) ₃ Si ₂ ) Spheroidization, in addition, a unique high-temperature intermediate annealing step is also applied between the hot rolling step and the cold rolling step, so that the grain orientation of the produced highly bendable aluminum magnesium silicon alloy sheet can be scattered and distributed No micro-cracks are generated during the folding process, while still having commercially acceptable yield strength after baking (PBYS).

In order to achieve the above object, the present invention provides a method for manufacturing a highly bendable aluminum magnesium silicon alloy sheet, comprising the steps of: providing an aluminum blank, comprising: 0.8 to 1.5 weight percent silicon; 0.2 to 0.7 weight percent magnesium; 0.1 to 0.5 weight percent iron; 0.01 to 0.2 weight percent manganese; the total amount of one or more impurities is less than 0.15 weight percent; and the rest is aluminum; a homogenization treatment of the aluminum embryo, including: 530 to 540 Perform a first homogenization step on the aluminum embryo at ℃ for 3 to 8 hours; and Perform a second homogenization step on the aluminum embryo at 560 to 570 °C for 9 to 12 hours; after performing the homogenization treatment The aluminum blank is subjected to a hot-rolling step to form a hot-rolled sheet, wherein a finishing temperature of the hot-rolling step is between 250 and 300°C; an intermediate annealing is performed on the hot-rolled sheet at 380 to 560°C Steps from 30 seconds to 3 hours; performing a cold rolling step on the hot rolled sheet after the intermediate annealing step to form a cold rolled sheet; and performing a heat treatment step on the cold rolled sheet to obtain the High bending aluminum magnesium silicon alloy sheet.

In an embodiment of the invention, a weight ratio of silicon to magnesium is between 1.4 and 2.0.

In an embodiment of the invention, the hot-rolled sheet is subjected to the intermediate annealing step at 540 to 560°C for 30 to 60 seconds.

In an embodiment of the invention, the hot rolling step further includes preheating the aluminum blank at 450 to 550°C for at least 2 hours.

In an embodiment of the invention, the reduction rate of forming the hot-rolled sheet from the aluminum blank is between 99% and 99.6%.

In an embodiment of the invention, the reduction rate of forming the cold-rolled sheet from the hot-rolled sheet is between 50% and 75%.

In an embodiment of the invention, the heat treatment step includes: performing a solution treatment on the cold-rolled sheet at 560 to 580°C for 40 to 60 seconds.

In an embodiment of the invention, the heat treatment step includes: performing an aging treatment after the solution treatment to make the highly bendable aluminum magnesium silicon alloy sheet have a predetermined strength.

In an embodiment of the invention, after the aluminum embryo is subjected to the first homogenization step, the aluminum embryo does not contain the Mg ₂ Si phase.

In an embodiment of the invention, after the second stage homogenization step is performed on the aluminum embryo, the aluminum embryo includes a spheroidized Al ₁₅ (Fe,Mn) ₃ Si ₂ phase.

In order to make the above and other objects, features, and advantages of the present invention more comprehensible, the preferred embodiments of the present invention will be specifically described below in conjunction with the accompanying drawings, which will be described in detail below. Furthermore, the terms of direction mentioned in the present invention, such as up, down, top, bottom, front, back, left, right, inner, outer, side, surrounding, center, horizontal, horizontal, vertical, longitudinal, axial, The radial direction, the uppermost layer or the lowermost layer, etc., are only the directions referring to the attached drawings. Therefore, the directional terminology is used to illustrate and understand the present invention, not to limit the present invention.

Please refer to FIG. 1, a manufacturing method 10 of an aluminum-magnesium-silicon alloy sheet according to an embodiment of the present invention mainly includes the following steps 11 to 16: providing an aluminum blank, including: 0.8 to 1.5 weight percent silicon; 0.2 To 0.7 weight percent magnesium; 0.1 to 0.5 weight percent iron; 0.01 to 0.2 weight percent manganese; the total amount of one or more impurities is less than 0.15 weight percent; and the rest is aluminum (step 11); A homogenization treatment includes: performing a first homogenization step on the aluminum embryo at 530 to 540°C for 3 to 8 hours; and performing a second homogenization step on the aluminum embryo at 560 to 570°C for 9 To 12 hours (step 12); performing a hot rolling step on the aluminum blank after the homogenization treatment to form a hot rolled sheet, wherein the finishing temperature of the hot rolling step is between 250 and 300°C (Step 13); performing an intermediate annealing step on the hot-rolled sheet at 380 to 560°C for 30 seconds to 3 hours (Step 14); performing a cold rolling step on the hot-rolled sheet after the intermediate annealing step, to Forming a cold-rolled sheet (step 15); and performing a heat treatment step on the cold-rolled sheet to produce the highly bendable aluminum magnesium silicon alloy sheet (step 16). The present invention will describe in detail the implementation details and principles of the above steps in the embodiments below.

Please refer to FIG. 1, a method 10 for manufacturing a highly bendable aluminum-magnesium-silicon alloy sheet according to an embodiment of the present invention is first step 11: providing an aluminum blank including: 0.8 to 1.5 weight percent silicon; 0.2 to 0.7 weight percent magnesium; 0.1 to 0.5 weight percent iron; 0.01 to 0.2 weight percent manganese; the total amount of one or more impurities is less than 0.15 weight percent; and the rest is aluminum.

In one embodiment, the purpose of adding silicon is to increase the precipitation of magnesium silicon (Mg-Si) strengthening phase (β”) after the sheet is painted and baked to improve the post-bake yield of the sheet. strength; PBYS). When the above sheet is used in the production of outer and inner sheet parts of automobiles, it can have sufficient dent resistance. The above effect is particularly significant when the silicon content is greater than 0.8wt.%. However, with the silicon content The increase will produce coarse magnesium silicon casting phase and precipitation phase, thereby reducing the flexibility of the sheet, especially when the silicon content is greater than 1.5wt.%.

In one embodiment, the purpose of adding magnesium is to form the aforementioned magnesium-silicon strengthening phase (β”) together with silicon, and its effect is better when the magnesium content is 0.25 wt.% or more. However, when the magnesium content is greater than 0.7 wt. %, the formability and bendability of the sheet deteriorates. In one embodiment, iron is an inevitable impurity component (>0.1wt.%) of raw materials (such as primary aluminum ingots), a small amount of iron can improve the The problem of rope streaks of aluminum-magnesium-silicon alloy sheets. However, when the iron content is higher than 0.5wt.%, coarse and brittle aluminum-iron-manganese-silicon (Al-(Fe, The Mn)-Si) compound not only deteriorates the ductility and toughness of the sheet, but also consumes the strengthening element silicon, and the strength of the sheet also decreases.

In one embodiment, the purpose of adding a trace amount of manganese element is to form fine aluminum-iron-manganese ((Mn,Fe)Al ₆ ) dispersed phases (Dispersoids) during the homogenization stage, so it can be used to suppress crystals during high-temperature solid solution The grain grows to avoid the rough orange peel phenomenon caused by coarse crystals on the surface of the sheet during stamping. However, if the manganese content is higher than 0.2 wt.%, similar to the effect of adding too much iron, there is also a risk of coarse crystals. In one embodiment, for example, the raw materials (primary aluminum ingot and master alloy ingot) in the aforementioned composition range may be smelted and subjected to direct quenching casting (Direct Chill Casting; DC) to obtain the aluminum embryo referred to herein as the present invention. .

In one embodiment, the weight ratio of silicon to magnesium is less than or equal to 2.0. In one example, a weight ratio of silicon to magnesium is between 1.4 and 2.0, such as 1.5, 1.6, 1.7, 1.8, or 1.9.

A method 10 for manufacturing a highly bendable aluminum magnesium silicon alloy sheet according to an embodiment of the present invention is followed by step 12: performing a homogenization treatment on the aluminum embryo, including: performing a first on the aluminum embryo at 530 to 540°C The stage homogenization step takes 3 to 8 hours; and the aluminum embryo is subjected to a second stage homogenization step at 560 to 570°C for 9 to 12 hours. In this step 12, the first homogenization step is mainly to heat the aluminum embryo through a specific temperature for a specific time to completely eliminate or almost completely eliminate the Mg ₂ Si phase in the aluminum embryo. It should be mentioned that the foregoing method of judging complete or almost complete elimination may be, for example, observing the crystalline phase in the aluminum embryo through a microscope and failing to find the Mg ₂ Si phase, or even trace amounts of the Mg ₂ Si Phase, but its content has not substantially affected the characteristics (such as bending characteristics, mechanical properties) of the highly bendable aluminum magnesium silicon alloy sheet. In addition, it is specifically mentioned that the Mg ₂ Si phase belongs to a low-melting point phase, and has a coarse, hard and brittle nature. Therefore, the first-stage homogenization step can effectively reduce the adverse effects caused by the Mg ₂ Si phase. In addition, the second homogenization step is mainly to heat the aluminum embryo through a specific temperature for a specific time, so that the originally elongated and irregularly shaped Al ₁₅ (Fe,Mn) ₃ Si ₂ phase produces a spheroidizing effect. Since the crystalline phase is the elongated and irregularly shaped Al ₁₅ (Fe,Mn) ₃ Si ₂ phase, it is easy to cause micro-cracks during the bending of the aluminum sheet, so this second stage of homogenization step can effectively reduce the non-spherical The adverse effects of Al ₁₅ (Fe,Mn) ₃ Si ₂ phase.

In one embodiment, the first homogenization step is performed before the second homogenization step to prevent the Mg ₂ Si phase from being dissolved in the aluminum base to achieve the elimination effect. Specifically, the processing temperature of the second homogenization step is higher than the processing temperature of the first homogenization step, so the Mg ₂ Si phase of the low-temperature phase will directly become the liquefied phase at high temperatures, and cannot exist in the form of solid solution In the aluminum base. After cooling, the liquefied phase will return to the Mg ₂ Si phase, and the elimination effect cannot be achieved.

A method 10 for manufacturing a highly bendable aluminum magnesium silicon alloy sheet according to an embodiment of the present invention is followed by step 13: performing a hot rolling step on the aluminum blank after the homogenization treatment to form a hot rolled sheet, wherein The finishing temperature of this hot rolling step is between 250 and 300°C. In this step 13, the aluminum blank may be preheated at 450 to 550°C for at least 2 hours (for example, between 2 and 24 hours), and then subjected to rolling treatment. In one embodiment, the reduction rate of forming the hot-rolled sheet from the aluminum blank is between 99% and 99.6%. In one example, for example, the aluminum blank has a thickness between 400 and 600 mm, and is hot rolled to a thickness of 2 to 3 mm.

The manufacturing method 10 of the high-bending aluminum magnesium silicon alloy sheet according to an embodiment of the present invention is followed by step 14: performing an intermediate annealing step on the hot-rolled sheet at 380 to 560°C for 30 seconds to 3 hours. In this step 14, it is mainly through the intermediate annealing step to recrystallize the elongated grains that are preferably arranged along the rolling direction in the hot-rolled sheet, and turn the grain orientation into a scattered distribution status. After the subsequent cold rolling step and heat treatment, the above-mentioned grain orientations can still be maintained in a scattered distribution state. In other words, through this intermediate annealing step, the highly bendable aluminum-magnesium-silicon alloy sheet produced by the present invention will not cause many grains arranged in the same orientation to be deformed in the same direction at the same time during bending, thereby avoiding strain concentration and micro The adverse effect of cracks in series. Therefore, the highly bendable aluminum-magnesium-silicon alloy sheet produced by the present invention can improve the bend resistance. In one embodiment, for example, the hot-rolled sheet may be subjected to the intermediate annealing step for 30 seconds to 60 seconds at 540 to 560°C. In another embodiment, the intermediate annealing step may be performed on the hot rolled sheet at 380 to 400°C for 1.5 to 3 hours.

The method 10 for manufacturing a highly bendable aluminum magnesium silicon alloy sheet according to an embodiment of the present invention is followed by step 15: performing a cold rolling step on the hot-rolled sheet after the intermediate annealing step to form a cold-rolled sheet . In this step 15, the reduction rate of forming the cold-rolled sheet from the hot-rolled sheet is, for example, between 50% and 75%. In a specific example, the hot rolled sheet has a thickness of 2 to 3 mm, and the cold rolling step is, for example, rolling the hot rolled sheet to a cold rolled sheet of 0.8 to 1.2 mm.

A method 10 for manufacturing a high-bendability aluminum-magnesium-silicon alloy sheet according to an embodiment of the present invention is followed by step 16: performing a heat treatment step on the cold-rolled sheet to obtain the high-bendability aluminum-magnesium-silicon alloy sheet . In this step 16, the heat treatment step may perform a solution treatment on the cold-rolled sheet at 560 to 580°C for 40 to 60 seconds, for example. In addition, aging treatment can also be performed according to the high bending aluminum-magnesium-silicon alloy sheet to achieve a predetermined strength. It should be mentioned that the heat treatment step mainly makes the high-bendability aluminum-magnesium-silicon alloy sheet as a whole have more uniform performance properties, and the aging treatment can improve the hardenability after baking. It is worth mentioning that the aging treatment can design the temperature and time used according to the actual application, so that the highly bendable aluminum magnesium silicon alloy sheet has the required post-baking hardenability.

In one embodiment, between the homogenization process and the hot rolling step, the method for manufacturing a highly bendable aluminum magnesium silicon alloy sheet of the present invention may further include a planing step for the aluminum embryo. The skinning step referred to here is to remove the brittle layer on the surface of the aluminum blank after the homogenization treatment, so as to further improve the surface quality of the produced highly bendable aluminum magnesium silicon alloy sheet.

In one embodiment, the manufacturing method of the highly bendable aluminum-magnesium-silicon alloy sheet of the present invention is only applicable to 6000 series aluminum alloys (that is, mainly contains 0.8 to 1.5 weight percent silicon, 0.2 to 0.7 weight percent magnesium, 0.1 to 0.5% by weight of iron and 0.01 to 0.2% by weight of manganese, the total amount of one or more impurities is less than 0.15% by weight, the rest is aluminum), other series of metal alloys or aluminum alloys can not be applied to the high bending of the present invention Folding aluminum magnesium silicon alloy sheet manufacturing method.

Several examples and several comparative examples are given below to illustrate that the highly bendable aluminum-magnesium-silicon alloy sheet produced by the manufacturing method of the present invention does have excellent bendability.

Example 1

First, an aluminum blank is provided, which meets the 6000 series aluminum alloy specifications, wherein the weight ratio of silicon to magnesium of the aluminum blank is about 2.0. Next, a homogenization treatment is performed on the aluminum embryo, which includes performing a first homogenization step on the aluminum embryo at about 530°C for about 8 hours, and performing a second homogenization on the aluminum embryo at about 570°C 9 hours. Next, a hot rolling step is performed on the aluminum blank after the homogenization treatment to form a hot rolled sheet, wherein a finishing temperature of the hot rolling step is between 250 and 300°C, formed from the aluminum blank The reduction rate of this hot-rolled sheet is about 99.6%. Thereafter, the hot rolled sheet is subjected to an intermediate annealing step at about 550°C for about 50 seconds. A cold-rolling step is performed on the hot-rolled sheet after the intermediate annealing step to form a cold-rolled sheet, wherein the reduction rate of forming the cold-rolled sheet from the hot-rolled sheet is about 50%. Next, a heat treatment step is performed on the cold-rolled sheet to obtain the highly bendable aluminum magnesium silicon alloy sheet of Example 1.

Examples 2 to 3 and Comparative Examples 1 to 5

The manufacturing methods of Examples 2 to 3 and Comparative Examples 1 to 5 are similar to Example 1, except that some of the parameters are different or some steps are not performed. For the detailed differences, please refer to Table 1 below.

Table I Si/Mg weight ratio Homogenization Intermediate annealing step Bending (level) Judgment of yield strength after baking Comparative example 1 2.0 no no 5 Commercially acceptable Comparative example 2 2.0 One period (550 to 570°C for 9 to 12 hours) no 4 Commercially acceptable Comparative Example 3 2.0 Two stages (530 to 540°C for 3 to 8 hours, and 560 to 570°C for 9 to 12 hours) no 3 Commercially acceptable Comparative Example 4 1.4 no no 3 Commercially acceptable Comparative example 5 1.4 Two stages (530 to 540°C for 3 to 8 hours; and 560 to 570°C for 9 to 12 hours) no 3 Commercially acceptable Example 1 2.0 Two stages (about 530℃ for 8 hours; and about 570℃ for 9 hours) About 550℃, about 50 seconds 2 Commercially acceptable Example 2 1.4 Two stages (about 540℃ for 3 hours; and about 560℃ for 12 hours) About 390℃, about 2 hours 2 Commercially acceptable Example 3 1.4 Two stages (about 535°C for 5 hours; and about 565°C for 10 hours) 550℃, about 50 seconds 1 Commercially acceptable

Examples 1 to 3 and Comparative Examples 1 to 5 were judged for bendability and yield strength after baking. Regarding the judgment of bendability, the judgment is mainly based on the Fiat Chrysler (FCA) standard. Specifically, each example and each comparative example are bent and compared with the photos in the standard, where: level 1 means no micro-cracks and the surface is smooth; level 2 means no micro-cracks and the surface is rough; level 3 means There are micro cracks on the outer surface; grade 4 indicates that the outer surface has medium cracks; grade 5 indicates that the outer surface has severe cracks. Levels 1 and 2 indicate commercial acceptance, and levels 3 to 5 indicate commercial acceptance. In addition, for the determination of the yield strength after baking, it is mainly determined by determining whether the yield strength after baking is greater than or equal to 200 MPa. If it is greater than or equal to 200 MPa, it is judged that the commercial use is acceptable; if it is less than 200 MPa, it is judged that the commercial use is not acceptable.

For Comparative Examples 1 and 2, it is mainly for Al-Mg-Si aluminum alloys with a Si/Mg ratio of 2.0. Comparative Examples 1 and 2 are respectively without homogenization and only one period of homogenization treatment, and are not subjected to any intermediate annealing treatment, resulting in their elongated low melting point phase (Mg ₂ Si) and/or crystalline phase (Al ₁₅ (Fe,Mn) ₃ Si ₂ ) failed to be dissolved back to the aluminum base by solid solution, and the grain arrangement is more directional, so its bendability is the worst (grade 5 and 4 respectively).

For Comparative Example 3, it is mainly for an Al-Mg-Si aluminum alloy with a Si/Mg ratio of 2.0, and is subjected to two-stage homogenization treatment. However, since it does not undergo an intermediate annealing step, the bendability is still unacceptable (grade 3).

Comparative Examples 4 and 5 are mainly for Al-Mg-Si aluminum alloys with a Si/Mg ratio of 1.4. Comparative Example 4 did not undergo homogenization and intermediate annealing, so the bendability was still unacceptable (grade 3). In addition, in Comparative Example 5, although the two-step homogenization treatment was performed, the intermediate annealing step was not performed, so the bendability was still unacceptable (level 3).

For Examples 1 and 2, Al-Mg-Si aluminum alloys with Si/Mg ratios of 2 and 1.4 were used, and after two stages of homogenization treatment and intermediate annealing steps with different parameters, commercially acceptable bending can be achieved Folding (level 2).

For Example 3, it adopts a low Si/Mg ratio (1.4), and undergoes two stages of homogenization treatment and a short-term intermediate annealing step at high temperature. The advantage of this method is that the two-stage homogenization process can eliminate the elongated low-melting point phase (Mg ₂ Si phase) and the irregular and hard and brittle crystalline phase (Al ₁₅ (Fe,Mn) ₃ Si ₂ ) Produce a spheroidizing effect. Then, the short-term intermediate annealing step at high temperature can change the grain arrangement from a preferred orientation along the rolling direction to a randomized distribution. Therefore, when the bending test is performed, the strain will not be excessively concentrated, thereby avoiding the generation of micro cracks. In addition, Example 3 has the best bendability test results (level 1).

In addition, although Examples 1 to 3 and Comparative Examples 1 to 5 have acceptable yield strength after baking (200 MPa or more), Comparative Examples 1 to 5 fail to pass the bendability test. Thus, it can be seen that the highly bendable aluminum magnesium silicon alloy sheet produced by the manufacturing method of the embodiment of the present invention does have the above effect.

It should be mentioned that the various parameters used in Comparative Examples 1 to 5 do not represent that the inventor of the present case recognized it as prior art. In particular, the manufacturing method in this case mainly uses specific steps and parameters to achieve the above effects, at least including: a specific aluminum composition (need to be 6000 series aluminum material); two stages of homogenization treatment steps of a specific parameter range (Used to remove or spheroidize a specific crystal phase); and an intermediate annealing step within a specific parameter range (which can turn the grain arrangement into a randomized distribution). In other words, at least the above three specific steps and parameters, as well as the related hot rolling, cold rolling and heat treatment steps, can be used to produce the highly bendable aluminum magnesium silicon alloy sheet of the present invention.

Although the present invention has been disclosed in preferred embodiments, it is not intended to limit the present invention. Anyone who is familiar with this skill can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the present invention The scope of protection shall be as defined in the scope of the attached patent application.

10: Method 11~16: Step

FIG. 1 is a schematic flow chart of a method for manufacturing a highly bendable aluminum magnesium silicon alloy sheet according to an embodiment of the invention.

10: Method

11~16: Step

Claims (10)

A method for manufacturing a highly bendable aluminum magnesium silicon alloy sheet, comprising the steps of: Provide an aluminum embryo, including: 0.8 to 1.5 weight percent silicon; 0.2 to 0.7 weight percent magnesium; 0.1 to 0.5 weight percent iron; 0.01 to 0.2 weight percent manganese; One or more impurities with a total amount of less than 0.15 weight percent; and The rest is aluminum; Perform a homogenization treatment on the aluminum embryo, including: Performing a first homogenization step on the aluminum embryo at 530 to 540°C for 3 to 8 hours; and Perform a second homogenization step on the aluminum embryo at 560 to 570°C for 9 to 12 hours; Performing a hot rolling step on the aluminum blank after the homogenization treatment to form a hot rolled sheet, wherein a finishing temperature of the hot rolling step is between 250 and 300°C; Performing an intermediate annealing step on the hot-rolled sheet at 380 to 560°C for 30 seconds to 3 hours; Performing a cold rolling step on the hot rolled sheet after the intermediate annealing step to form a cold rolled sheet; and A heat treatment step is performed on the cold-rolled sheet to obtain the highly bendable aluminum magnesium silicon alloy sheet. The method for manufacturing a high-bending aluminum-magnesium-silicon alloy sheet according to claim 1, wherein a weight ratio of silicon to magnesium is between 1.4 and 2.0. The method for manufacturing a high-bendability aluminum magnesium silicon alloy sheet according to claim 1, wherein the hot-rolled sheet is subjected to the intermediate annealing step at 540 to 560°C for 30 seconds to 60 seconds. The method for manufacturing a high-bendability aluminum magnesium silicon alloy sheet according to claim 1, wherein the hot rolling step further includes preheating the aluminum blank at 450 to 550°C for at least 2 hours. The method for manufacturing a high-bendability aluminum-magnesium-silicon alloy sheet according to claim 1, wherein the reduction rate of forming the hot-rolled sheet from the aluminum blank is between 99% and 99.6%. The method for manufacturing a high-bendability aluminum-magnesium-silicon alloy sheet according to claim 1, wherein the reduction rate of forming the cold-rolled sheet from the hot-rolled sheet is between 50% and 75%. The method for manufacturing a high-bendability aluminum magnesium silicon alloy sheet according to claim 1, wherein the heat treatment step includes: performing a solution treatment on the cold-rolled sheet at 560 to 580°C for 40 to 60 seconds. The method for manufacturing a high-bendability aluminum-magnesium-silicon alloy sheet according to claim 7, wherein the heat treatment step includes: performing an aging treatment after the solution treatment to make the high-bendability aluminum-magnesium-silicon sheet The alloy sheet has a predetermined strength. The method for manufacturing a high-bending aluminum-magnesium-silicon alloy sheet according to claim 1, wherein the aluminum embryo does not contain an Mg ₂ Si phase after performing the first homogenization step. The method for manufacturing a high-bendability aluminum magnesium silicon alloy sheet according to claim 1, wherein after performing the second homogenization step, the aluminum embryo comprises spheroidized Al ₁₅ (Fe, Mn) ₃ Si ₂ phase.

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