JP2008144279A - Aluminum material having high moldability - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aluminum material capable of achieving a high hem bendability and a high sheet moldability. <P>SOLUTION: The aluminum material is composed of crystal grains of different crystal orientations comprising Brass-oriented grains, Copper-oriented grains and the balance being other crystal-oriented grains. The occupancy ratio of the Brass-oriented grains is 0.2-0.4, the occupancy ratio of the Copper-oriented crystal grains is 0.05-0.1, the total occupancy ratio of these crystal orientations is 0.25-0.5, and the balance is other crystal-oriented grains. An automobile member is obtained using the same. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to an aluminum material, and in particular, aluminum having excellent hem bendability required when assembling automobile body sheets, automobile parts, machine parts, and plate formability such as press forming when forming a body or a casing. Regarding materials.

Automobiles are aluminized, such as body sheets. Outer materials are excellent in bake hardness (property that precipitates and hardens when heated during paint baking), and have high strength after paint baking (6000 series) (Al-Mg- Si-based) aluminum alloys are frequently used, and 5000-based (Al-Mg-based) aluminum alloys having excellent drawability are used as the inner material.
The outer material made of this 6000 series aluminum alloy is required to be superior in bending workability called hem bending, which is usually used by caulking with the inner material, but the 6000 series (Al-Mg-Si based alloy plate) There is a problem that bending workability is inferior, and particularly in a material solution-treated at a high temperature in order to enhance the bake hardness, the hem bending workability is remarkably deteriorated.

  Further, the outer material of the 6000 series aluminum alloy is required to have good press formability, which is a kind of plate forming with less restrictions in order to determine the design of an automobile. The press formability is inferior to that of aluminum-based aluminum alloy plates, and improvements are desired in order to integrate the materials used in consideration of the problem of recycling automobile parts.

  In such a situation, for improving the bending workability, a method for controlling the surface hardness of the aluminum alloy plate (for example, see Patent Document 1), a method for controlling the crystal grain size and the precipitate size (for example, Patent Document 2). 3), a method for controlling the crystal orientation of the surface of the aluminum alloy plate (for example, see Patent Documents 4 and 5), a method for controlling the crystal orientation of the entire aluminum alloy plate (for example, see Patent Document 6), the surface of the aluminum alloy A method of controlling the bending workability by controlling the crystal orientation from a certain depth to a certain depth (see, for example, Patent Document 7) has been proposed.

  In order to improve plate forming, a method of improving press formability by controlling the rankford value in each of the 0 ° direction, 45 ° direction, and 90 ° direction with respect to the rolling direction of the aluminum alloy plate (for example, patent document) 8, 9), and a method for improving press formability and bending workability by controlling the relationship between tensile strength and proof stress and the crystal grain size and precipitation free zone (PFZ) of the aluminum alloy plate surface (for example, Patent Document 10). Have been proposed).

  It is known that the relationship between the crystal orientation of crystal grains in plate forming and the quality of plate formability can be optimally designed based on the results obtained from single crystal orientation materials of Cube, Brass, and Copper orientations. (For example, refer nonpatent literature 1). Moreover, the difference in the deformability of the unidirectional grain material in deep drawing which is a kind of plate forming is known (for example, see Non-Patent Document 2).

  However, especially for automobile body seats, it has strong plate forming properties such as hem bending, which is necessary for the assembly of the body, and plate formability typified by press formability required for precise processing of the body shape. Although both are required at a high level, it was possible to improve only the hem bendability, but at the same time it was difficult to raise the plate formability to the same level as the conventional steel body, conversely the plate formability Attempting to raise the level of hem lowers the level of hem bendability, and also controls the press formability and bending by controlling the relationship between tensile strength and proof stress and the crystal grain size and precipitation free zone (PFZ) of the aluminum alloy sheet surface. Even with a method for improving the properties, it was difficult to obtain a high level of plate formability.

JP 2003-129201 A JP 2003-221737 A JP 2003-268472 A JP 2003-226926 A JP 2003-226927 A JP 2003-268475 A JP 2004-27253 A JP 2002-146462 A JP 2004-10982 A JP 2003-105473 A Eiji Nakamachi, Yoshinori Hamada: Plasticity and processing, 39-446 (1998), 252. Hideo Morimoto, Eiji Nakamachi: Furukawa Electric Times, 103 (1999), 7.

Under such circumstances, the present inventors have examined the influence of the crystal orientation distribution of crystal grains on hem bendability and plate formability, and as a result, found the present invention that can achieve both hem bendability and plate formability at a high level. It was.
An object of the present invention is to provide an aluminum material that can achieve both a high degree of hem bendability and sheet formability.
Specifically, by controlling the ratio of the three of the Cube orientation, the Brass orientation, and the Copper orientation among the crystal orientations indicated by the crystal grains constituting the aluminum material, the sharp bendability such as hem bending and press molding are controlled. It is an object of the present invention to provide an aluminum material excellent in both properties of plate formability.

  Usually, the texture of a rolled sheet is expressed by the relationship between the rolled surface of the sheet and the rolling direction ((ABC) and <DEF>) (A, B, C, D, E, and F represent integers). Here, the crystal orientation distribution of the crystal texture of the plate material represents a distribution of crystal orientations specific to each plate material with respect to a random orientation expressed by a ratio of crystal orientations.

  In the present invention, evaluation was made on the Cube orientation, the Brass orientation, and the Copper orientation. The Cube orientation represents the (100) <001> orientation, the Brass orientation represents the (011) <211> orientation, and the Copper orientation represents the (112) <111> orientation. Since the actual orientation of the plate material deviates from the ideal orientation of each of the Cube orientation, the Brass orientation, and the Copper orientation, each crystal based on the ideal orientation of each crystal of the Cube orientation, the Brass orientation, and the Copper orientation. It is assumed that crystal orientations up to a range shifted by 5 degrees from the ideal orientation are also included in the Cube orientation, the Brass orientation, and the Copper orientation, respectively.

The above problem has been solved by the following technical means:
(1) An aluminum material composed of crystal grains having different crystal orientations, wherein the crystal grains are Cube-oriented crystal grains, Brass-oriented crystal grains, Copper-oriented crystal grains, and the balance is the other-order crystal grains. The occupancy ratio of crystal grains in the orientation is 0.3 to 0.7, the occupancy ratio of the crystal grains in the Brass orientation is 0.1 to 0.5, the occupation ratio of the crystal grains in the Copper orientation is 0.2 or less, and these An aluminum material characterized in that the total occupancy of the orientation is 0.4 to 1.0, and the balance is crystal grains of other crystal orientations,

(2) An aluminum material composed of crystal grains having different crystal orientations, wherein the crystal grains are Cube-oriented crystal grains, Brass-oriented crystal grains, Copper-oriented crystal grains, and the balance is the other-order crystal grains. The occupancy of crystal grains in the orientation is 0.4 to 0.6, the occupancy of the crystals in the Brass orientation is 0.2 to 0.4, the occupancy of the crystals in the Copper orientation is 0.05 to 0.1, And an aluminum material characterized in that the total occupancy of these orientations is 0.65 to 0.9, and the balance is grains of other crystal orientations,

(3) An aluminum material composed of crystal grains having different crystal orientations, wherein the crystal grains are composed of a Brass-oriented crystal grain, a Copper-oriented crystal grain, and the balance is the other-order crystal grain. Occupancy rate is 0.2 to 0.4, Copper orientation crystal grain occupancy rate is 0.05 to 0.1, total occupancy rate of these orientations is 0.25 to 0.5, and the rest is other An aluminum material characterized in that it is composed of crystal grains having a crystal orientation of

(4) The ratio of bending radius / thickness is 0 in the range in which cracking on the bending surface in the hem bendability has no plate cracking property at a protruding height of 30 mm and no cracking occurs on the protruding surface. The aluminum material according to any one of (1) to (3), wherein the aluminum material has a hem bendability of .5 or less,

(5) The ratio of the bending radius / thickness is 0 in the range where there is a plate formability that does not cause cracks on the extended surface at an extended height of 50 mm, and no crack occurs on the bent surface in hem bendability. The aluminum material according to any one of (1) to (3), wherein the aluminum material has a hem bendability of .25 or less,

(6) The aluminum material is an aluminum alloy composed of Mg of 0.25 to 1.0 mass%, Si of 0.5 to 1.3 mass%, the balance Al and inevitable impurities ( The aluminum material according to any one of 1) to (5),

(7) The aluminum material has Mg of 0.25 to 1.0 mass%, Si of 0.5 to 1.3 mass%, Cu, Zn, Mn of 1 mass% or less, Fe of 0.40 mass% or less, Ti, The aluminum material according to any one of (1) to (5), wherein the aluminum material includes 0.1 mass% or less of Cr, and is an aluminum alloy including the balance Al and unavoidable impurities,

(8) The aluminum material has Mg of 0.40 to 1.0 mass%, Si of 0.5 to 1.3 mass%, Cu and Mn of 1 mass% or less, Zn of 0.3 mass% or less, and Fe of 0.20 mass%. The aluminum material according to any one of the above (1) to (5), which is an aluminum alloy containing Ti and Cr in an amount of 0.1 mass% or less and the balance being Al and inevitable impurities,

(9) The aluminum material has Mg of 0.25 to 1.0 mass%, Si of 0.5 to 1.3 mass%, Cu, Zn, Mn of 1 mass% or less, Fe of 0.40 mass% or less, Ti, Any of (1) to (5) above, characterized in that it is an aluminum alloy containing 0.1 mass% or less of Cr and further containing 0.20 mass% or less of V and Zr, and the balance being Al and inevitable impurities. The aluminum material according to item 1,

(10) The aluminum material has Mg of 0.40 to 1.0 mass%, Si of 0.5 to 1.3 mass%, Cu and Mn of 1 mass% or less, Zn of 0.3 mass% or less, and Fe of 0.20 mass%. The above (1) to (5), characterized in that it is an aluminum alloy containing 0.1 mass% or less of Ti and Cr and further containing 0.1 mass% or less of V and Zr, and the balance being Al and inevitable impurities. Aluminum material according to any one of

(11) An automobile member using the aluminum material according to (4) or (5), and (12) an automobile member using the aluminum material according to any one of (6) to (10). .

  The above and other features and advantages of the above technical means will become more apparent from the following description, with reference where appropriate to the accompanying drawings.

1 (a) to 1 (c) are diagrams schematically showing the hem bending workability test method performed in Example 1, and FIG. 1 (a) shows the setting of the test material. (B) shows punch indentation, and FIG. 1 (c) shows contact bending (tightening) by a vise.

The technical means will be described in detail below.
The above technical means is capable of controlling the ratio of the Cube orientation, the Brass orientation, and / or the Copper orientation out of the crystal orientations of the crystal grains constituting the aluminum material, thereby optimizing the sharpness such as hem bending. We have found a material that satisfies both high-level bending and plate forming such as body press molding. For example, the occupancy ratio of Cube orientation crystal grains is 0.3 to 0.7, and the occupancy ratio of Brass orientation crystal grains Is 0.1 to 0.5, the occupancy ratio of the Copper orientation crystal grains is 0.2 or less, and the total occupancy ratio of each crystal orientation of the Cube orientation, the Brass orientation, and the Copper orientation is 0.4 to 1.0. An aluminum material that satisfies the above requirements exhibits good bendability and plate formability.
The relationship between the occupancy ratio of each crystal orientation of the crystal grains constituting the aluminum material and both characteristics will be described below.

  First, it is known that the crystal orientation density of the Cube orientation crystal grains has a great influence on the hem bending, and as the crystal orientation density becomes higher than the crystal orientation density of the random orientation crystal grains, the hem bending is increased. It is known to be good. Also in the above technical means, it is preferable to increase the occupancy ratio of the crystal grains having the Cube orientation in order to improve the hem bending. However, an increase in the occupation ratio of the Cube-oriented crystal grains results in a significant loss of plate formability.

  Therefore, in the above technical means, as a result of various studies, the range of the occupation ratio is preferably 0.3 to 0.7, and more preferably 0.4 to 0.6. In the lower limit range of this range, practically sufficient hem bendability can be provided, and in the upper limit range, plate formability sufficient to perform press molding of the body sheet to the automobile outer shape is maintained.

  Second, when the occupancy ratio of the Brass orientation crystal grains is high, the plate formability is improved as opposed to the case where the occupancy ratio of the Cube orientation crystal grains is high. However, the effect of Brass-oriented crystal grains on heme bendability is not known, and the influence of the occupation ratio is also unknown.

  Therefore, in the above technical means, as a result of examining the influence of the occupancy ratio of the Brass-oriented crystal grains on the hem bending and plate forming, the occupancy ratio range is 0.1 to 0.5, preferably 0.2 to 0. .4. Within the occupancy range of the Cube orientation crystal grains, by setting the occupancy ratio of the Brass orientation crystal grains to 0.1 to 0.5, both hem bending and plate forming can be obtained at a high level. . If the material is out of this range, either hem bending or plate forming will be excellent, or both will be at a low level.

  Third, the occupation ratio of Copper-oriented crystal grains is 0.2 or less, preferably 0.05 to 0.15, and more preferably 0.05 to 0.1. The reason for this limitation is that the Copper-oriented crystal grains are known to exhibit the same function as the Brass-oriented crystal grains for plate forming. However, in the above technical means, as another effect, It has been found that the presence of the Copper-oriented crystal grains in the ratio of the occupation ratio shows an effect of raising both the hem bendability and the plate forming level. The Cube-oriented crystal grains and the Brass-oriented crystal grains It is expected that it will work as a cushioning material for both.

Next, a method for calculating the crystal orientation occupancy will be described.
An aluminum plate material to be used for measurement, here an aluminum plate material having a predetermined thickness (for example, 1 mm thickness) is prepared, and after degreasing the surface with an oil cleaning material such as acetone, an oxide layer removing agent (for example, suitable for the material of the aluminum plate material) The aluminum plate from which the oxide layer on the surface was removed using aqua regia or the like for an aluminum alloy was mirror-finished by electrolytic polishing, and the vicinity of the surface layer of the aluminum plate was used as a test material to measure crystal orientation.
Next, using this test material, the crystal orientation of the crystal grains is measured by an electron backscatter diffraction pattern (hereinafter abbreviated as EBSP).
The measurement is performed in a thermionic emission scanning electron microscope, each crystal orientation of the crystal grains in the unit area is measured, and the Cube orientation relative to the number of all crystal grains in the unit area is 1. The ratio of the number of crystal grains in the Brass orientation and Copper orientation was determined, and the value was used as the occupation ratio. For example, when the total number of crystal grains in a 1.0 mm square is 100, the total number of crystal grains in the Cube, Brass, and Copper orientations is 100 (that is, there are no crystal grains in other crystal orientations). In this case, the total occupancy (total occupancy) of each crystal grain in the Cube orientation, the Brass orientation, and the Copper orientation is 1.

  The aluminum material according to the above technical means exhibits good bendability and plate formability at the crystal orientation occupancy ratio because the crystal structure is a face-centered cubic structure. Examples of the material having a face-centered cubic structure include an Al alloy, a Cu alloy, a Ni alloy, an Ag alloy, and an Au alloy, and the Al alloy exhibits a remarkable effect.

As the Al alloy, an Al—Mg—Si alloy composed of 0.25 to 1.0 mass% of Mg, 0.5 to 1.3 mass% of Si, and the balance Al and inevitable impurities exhibits a great effect. preferable.
Si and Mg contained as essential elements in this Al—Mg—Si alloy are precipitated as Mg ₂ Si compounds and contribute to improving the strength. If the amount is too small, the effect is not sufficient, and if the amount of Si is too large. A natural aging phenomenon may occur, causing a significant decrease in bending workability. On the other hand, if the amount of Mg is too large, a large amount of coarse Mg ₂ Si compound is precipitated, and as a result, the amount of solid solution is greatly reduced, which may cause a decrease in bending workability and bake hardness. Furthermore, for example, in order to slightly increase the strength of the plate material, it is preferable to set the lower limit value of Mg to 0.40% or more.

In addition to the Mg and Si, Cu, Zn, Mn, Cr, Ti, etc. may be added. Addition of Cu increases strength, ductility, degreasing, chemical conversion treatment, etc. Addition of Zn improves degreasing and chemical conversion processing, and addition of Mn, Ti, Cr promotes refinement of crystal grains and bending. Although it works to improve the properties, if these elements are added excessively, corrosion resistance and ductility are reduced.
As described above, the addition of Cu and Zn has no practical problem as long as any element is in the range of 1 mass% or less, but considering the balance between strength, ductility, degreasing, chemical conversion treatment, corrosion resistance, and ductility. The upper limit can be appropriately determined to a level of 1 mass% or less. In particular, in order to increase the corrosion resistance of the plate material, it is preferable to add Zn to 0.3 mass% or less.
In addition, the amount of Mn, Cr, and Ti that promotes the refinement of crystal grains and improves the bending workability needs to be 1 mass% or less for Mn, and 0.1 mass% or less for Ti or Cr. preferable.

In addition to the above elements, Fe contained as an impurity forms a crystallized material that is harder than the Mg ₂ Si compound, and forms a large strain around the element to promote the propagation of cracks. It is preferable to set it to 0.40 mass% or less, more preferably 0.20 mass% or less. Furthermore, V, Zr, etc. can be included in the range of 0.20 mass% or less as needed for the purpose of crystal grain refinement. V and Zr addition amounts do not affect the plate formability such as hem bendability and press formability in the range of 0.20 mass% or less, but may be 0.1 mass% or less in consideration of corrosion resistance and ductility. preferable.

  ADVANTAGE OF THE INVENTION According to this invention, the high hem bendability required at the time of assembling an automobile body sheet, an automobile part, a machine part, etc. and an aluminum material excellent in plate formability such as press forming at the time of body formation or housing formation are provided. can do.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail based on an Example, this invention is not limited to these.

(Example 1)
0.5 mass% for Mg, 0.9 mass% for Si, 0.06 mass% for Mn, 0.07 mass% for Fe, 0.10 mass% for Cu, and all of Zn, Ti and Cr are equal to or less than 0.05 mass% In addition, an Al alloy composed of the remaining Al is melt-cast into an ingot having a thickness of 500 mm by a conventional method, and the ingot is homogenized at 540 ° C. for 6 hours, and then heated under conditions of a start temperature of 500 ° C. and an end temperature of 200 ° C. A hot rolled plate having a thickness of 10 mm was obtained by rolling. Next, this hot-rolled sheet was cold-rolled to a predetermined thickness such that a finished base sheet having a thickness of 1 mm was obtained at a finishing rate of 20%, 30%, 50%, 70%, and 90%. In addition, about the sample whose finishing cold work rate is 90%, the finishing base plate of thickness 1mm was obtained directly from the hot-rolling board of thickness 10mm.
Next, this cold-rolled sheet having a predetermined thickness was annealed at 325 ° C. for 2 hours and subjected to finish cold-rolling to produce a finished blank having a thickness of 1 mm. The finished base plate was subjected to a solution treatment at 500 ° C. using a continuous annealing furnace and a stabilization treatment at 100 ° C. for 24 hours to obtain a test material.

The crystal orientation occupancy was measured by the method described in the preceding paragraph and is shown in Table 1.
Specimen No. listed in Table 1 No. 1 was finish-rolled at a finish cold work rate of 20%. 2 is 30%. 3 is 50%. 4 is 70%. 5 is 80%. 10 is 10%. No. 11 was subjected to finish cold rolling at a finish cold work rate of 90%.
Note that the occupancy of each crystal orientation includes crystal orientations that are 5 degrees apart from the ideal orientation of each crystal of the Cube orientation, the Brass orientation, and the Copper orientation.

Using the produced test material, a 180 ° C. bending test and a stretch forming test were performed, and hem bending workability and plate formability were evaluated, respectively.
First, regarding the hem bending workability, 180 ° bending is performed in which the pre-strain is applied as shown in FIG. 1 (a), the punch is pushed up to a bending angle of 170 ° in FIG. 1 (b), and the vise clamping shown in FIG. Using the processing test, the tip curvature R of the punch 1 was changed to 0.25, 0.5, 0.75, and 1.0 mm, and the test was repeated for each tip curvature with the number of tests of 5 sheets. The minimum value of the tip curvature at which no crack occurs is shown in the column of hem bending workability in Table 1. Therefore, in this test, the smaller the tip curvature that does not cause rough skin and cracks, the better the hem bending workability.

Regarding the stretch formability, after cutting the test material into 300 mm squares and applying lubricating oil on both sides, the stretch test was repeated under the condition of a stretch height of 50 mm using a ball head punch with a diameter of 100 mm. The test was conducted to evaluate the stretch formability.
Table 1 shows all specimens with no cracks as "O", specimens with only one crack as "△", and specimens with two or more cracks as "X". .

  The strength and elongation of the prepared specimens were 230 to 240 MPa in strength, 130 to 140 MPa in 0.2% proof stress, and 30% or more in elongation, except for specimens with a finish cold working rate of 90%. . The test material with a finish cold working rate of 90% was the same in strength and 0.2% yield strength as the other test materials, but the elongation was as low as 17%.

表１から明らかなように、各結晶方位が本技術的手段の範囲内の供試材Ｎｏ．１からＮｏ．５では、ヘム曲げ加工性および板成形性共に良好であるのに対して、Ｃｕｂｅ方位の占有率割合が低く、Ｂｒａｓｓ方位の占有率割合が多い供試材Ｎｏ．１０では、両特性共に優れず、殆どの結晶粒がＣｕｂｅ方位を示す供試材Ｎｏ．１１では、ヘム曲げ加工性には優れるが、反面板成形性が劣っていることがわかる。すなわち、前記（８）項を満足する優れた材料が得られることが判る。
なお、Ｍｇを０．５ｍａｓｓ％、Ｓｉを０．９ｍａｓｓ％のみを添加し、残部がＡｌと不可避的不純物からなる材料を実施例１と同様の工程で製造したところ、前記（６）項を満足する優れた材料が得られた。また、Ｆｅ添加量のみを０．２５ｍａｓｓ％に変更した材料と、Ｆｅ添加量を０．２５ｍａｓｓ％、Ｃｕ添加量を０．１５ｍａｓｓ％と変更した材料を実施例１と同様の工程で、同様の試作材を製造したところ、両者とも、前記（７）項を満足する優れた結果が得られた。さらに、実施例１の材料に、Ｖ，Ｚｒをともに０．１５ｍａｓｓ％添加した材料と、Ｖ，Ｚｒをともに０．０８ｍａｓｓ％添加した材料を実施例１と同様の工程で、同様の試作材を製造したところ、両者とも、前記（９）または（１０）項を満足する優れた結果が得られた。

As can be seen from Table 1, each of the crystal orientations within the scope of the technical means No. 1 to No. No. 5, while the hem bending workability and the plate formability are both good, the test piece No. No. 1 has a low occupancy ratio in the Cube orientation and a large occupancy ratio in the Brass orientation. No. 10, both properties are not excellent, and most of the crystal grains have a Cube orientation. No. 11 is excellent in hem bending workability but is inferior in plate formability. That is, it can be seen that an excellent material satisfying the item (8) can be obtained.
In addition, when only 0.5 mass% of Mg and 0.9 mass% of Si were added, and the balance was made of Al and inevitable impurities in the same process as in Example 1, the above item (6) was satisfied. An excellent material was obtained. In addition, a material in which only the Fe addition amount is changed to 0.25 mass% and a material in which the Fe addition amount is changed to 0.25 mass% and the Cu addition amount is changed to 0.15 mass% are the same as those in the first embodiment. When prototype materials were manufactured, both obtained excellent results satisfying the item (7). Further, the same prototype material was prepared in the same process as in Example 1 except that the material of Example 1 was added with 0.15 mass% of both V and Zr, and the material with both V and Zr added of 0.08 mass%. As a result, both produced excellent results satisfying the item (9) or (10).

  Since the aluminum material of the present invention is excellent in hem bendability and plate formability, it can be suitably used for automobile body sheets, automobile parts, machine parts and the like.

  While this invention has been described in conjunction with its embodiments, we do not intend to limit our invention in any detail of the description unless otherwise specified and are contrary to the spirit and scope of the invention as set forth in the appended claims. I think it should be interpreted widely.

Claims (10)

  An aluminum material composed of crystal grains having different crystal orientations, wherein the crystal grains are composed of a Brass orientation crystal grain, a Copper orientation crystal grain, and the balance is the other-order crystal grain, and the occupation ratio of the Brass orientation crystal grains is 0.2 to 0.4, the crystal grain occupancy of Copper orientation is 0.05 to 0.1, the total occupancy of these orientations is 0.25 to 0.5, and the balance is other crystal orientations An aluminum material characterized by being excellent in plate formability composed of crystal grains.   It has a plate formability that does not cause cracks on the overhanging surface at an overhanging height of 30 mm, and the range in which no cracks occur on the bending surface in the hem bendability is 0.5 or less in the ratio of bending radius / plate thickness. The aluminum material according to claim 1, which has a hem bendability of:   It has a plate formability that does not cause cracks on the extended surface at an extended height of 50 mm, and the range in which no cracks occur on the bent surface in the hem bendability is 0.25 or less in terms of the ratio of bending radius / plate thickness. The aluminum material according to claim 1, which has a hem bendability of:   The aluminum material is an aluminum alloy composed of 0.25 to 1.0 mass% of Mg, 0.5 to 1.3 mass% of Si, and the balance Al and inevitable impurities. The aluminum material according to any one of the above.   The aluminum material has Mg of 0.25 to 1.0 mass%, Si of 0.5 to 1.3 mass%, Cu, Zn, and Mn of 1 mass% or less, Fe of 0.40 mass% or less, and Ti and Cr of 0. The aluminum material according to any one of claims 1 to 3, wherein the aluminum material is an aluminum alloy including a balance of Al and unavoidable impurities.   The aluminum material is Mg 0.40 to 1.0 mass%, Si 0.5 to 1.3 mass%, Cu and Mn 1 mass% or less, Zn 0.3 mass% or less, Fe 0.20 mass% or less, Ti The aluminum material according to any one of claims 1 to 3, wherein the aluminum material is an aluminum alloy containing 0.1 mass% or less of Cr and the balance being Al and inevitable impurities.   The aluminum material has Mg of 0.25 to 1.0 mass%, Si of 0.5 to 1.3 mass%, Cu, Zn, and Mn of 1 mass% or less, Fe of 0.40 mass% or less, and Ti and Cr of 0. The aluminum according to any one of claims 1 to 3, which is an aluminum alloy containing 0.1 mass% or less, further containing 0.20 mass% or less of V and Zr, and the balance being Al and inevitable impurities. material.   The aluminum material is Mg 0.40 to 1.0 mass%, Si 0.5 to 1.3 mass%, Cu and Mn 1 mass% or less, Zn 0.3 mass% or less, Fe 0.20 mass% or less, Ti 4. An aluminum alloy containing 0.1 mass% or less of Cr, further containing 0.1 mass% or less of V and Zr, and comprising the balance Al and inevitable impurities. Aluminum material described in 1.   The automobile member using the aluminum material of Claim 2 or Claim 3.   The motor vehicle member using the aluminum material of any one of Claims 4-8.

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