JP2005125341A - Aluminum blank material for press formation - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aluminum blank material having excellent press-formability. <P>SOLUTION: In the aluminum blank material unified with a butt-joining of two platy aluminum basic materials 12, 14 different in plate thicknesses, in the case of using t1 for plate thickness and σ1 for tensile strength of either one of the platy basic material 12(14) in two platy aluminum basic materials and t2 for plate thickness and σ2 for tensile strength of the other one 14(12) therein, the ratio: R=(t1×σ1)/(t2×σ2) of the product: t1×σ1 of the plate thickness and the tensile strength in the one side of the platy basic material 12(14) to the product: t2×σ2 of the plate thickness and the tensile strength in the other side of the platy basic material 14(12), is constituted so as to become the value in the range of 0.8-1.25. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a press-molding aluminum blank, and more particularly to a technique for improving the press-formability of a press-molding aluminum blank obtained by integrating two plate-like aluminum base materials by butt joining. It is.

  Conventionally, by using a plate material (aluminum plate material) made of aluminum or an aluminum alloy as a blank material (material) for press molding and performing press molding on the blank material, for example, daily necessities, building materials, aircraft or ships A wide variety of press products such as outer panels are manufactured.

  Further, in recent years, when obtaining such a pressed product made of aluminum, two aluminum plate members (plate-like aluminum base materials) are integrated by being brought into contact with each other and generally called a tailored blank material. A technology for obtaining a single aluminum blank for press molding and performing a predetermined press molding on the blank for press molding is, for example, a body panel of an outer material of an automobile or an inner material (vehicle body). Has been adopted for the manufacture of pressed products that give panels).

  In such a press molding technology, when a blank material for press molding is formed by butt-joining two plate-like aluminum base materials and integrating them, a blank material for press molding is obtained. In addition, waste materials due to cutting and the like are not generated at all, and a small aluminum plate that cannot be used in general press molding technology can be used as a blank forming material, thereby reducing the material cost. Reduction can be advantageously achieved. In addition, when the press molding technique is used, if two plate-like aluminum base materials having different thicknesses are butt-joined and a partially thickened press molding blank is used, a predetermined thickness is used. While the part is a thick part with high strength and rigidity, while the other part is a lightweight thin part, it is only necessary for the necessary part in a state where lightness is secured as much as possible. A press product to which strength and rigidity are imparted can be easily obtained.

  Further, in such a press molding technique, when a blank material formed by integrating two plate-like aluminum base materials having a difference in plate thickness is used, it is possible to stably obtain a press product having high quality performance. Therefore, it is necessary to stabilize the bonding quality of the blank material regardless of the thickness difference between the base materials to be bonded. When forming an aluminum blank for press molding in which the base material is integrated, the two plate-like aluminum base materials are formed by a friction stir welding method capable of forming a joint having sufficient joint strength by solid phase joining. Various attempts have been made to butt-join (for example, see Patent Documents 1 to 6).

Under such circumstances, the present inventors actually performed press molding using an aluminum blank for press molding in which two plate-like aluminum base materials having different thicknesses are butt-joined by a friction stir welding method. However, in such press molding, it is true that sufficient bonding strength is exhibited at the joint of the blank material, and breakage at the joint can be effectively eliminated. It has been recognized so far that the small thin part deforms preferentially and greatly over the thick part with a large plate thickness and becomes easy to break, so that the press shape and the processing amount are naturally limited. It turns out that the problem that did not exist is inherent.
JP-A-10-249553 Japanese Patent Laid-Open No. 20000016676 JP 2001-267979 A JP 2001-321968 A JP 2002-224858 A JP 2002-331370 A

  Here, the present invention has been made in the background as described above, and the solution is to butt-join two plate-like aluminum base materials having different plate thicknesses. In the aluminum blank material for press molding, which is integrated by forming a thick part and a thin part, the preferential and large deformation to the thick part of the thin part during press molding is eliminated or suppressed. Accordingly, it is an object of the present invention to provide a novel structure in which press formability (press workability) can be advantageously improved.

  And, in order to solve such problems, the inventors of the present invention have material characteristics of an aluminum blank material for press molding that is integrated by butt-joining two plate-like aluminum base materials having different plate thicknesses. As a result of various examinations from various viewpoints, the thickness and tensile strength of each base material between two plate-like aluminum base materials that give such a blank material are different. By optimizing the balance, the thin-walled portion given by the thin plate-like aluminum base material and the thick-walled portion given by the thick plate-shaped aluminum base material are almost uniform during press forming of the blank material. I found out that it can be transformed into

That is, the present invention has been completed based on such knowledge, and the first aspect thereof is that two plate-like aluminum base materials having different plate thicknesses are formed between end surfaces of each other. In an aluminum blank material used for press molding, which is integrated by joining the butted portions under the mutually butted state in the two plate-shaped aluminum base materials The plate thickness of one of the plate-like base materials is t ₁ , the tensile strength is σ ₁ , and the plate thickness of any one of the plate-like base materials is t ₂ , and the tensile strength is σ ₂ The product of the plate thickness and tensile strength of the one plate-shaped base material: t ₁ × σ ₁ and the product of the plate thickness and tensile strength of the other plate-shaped base material: t ₂ × σ ₂ The value of the ratio: R = (t ₁ × σ ₁ ) / (t ₂ × σ ₂ ) is a value within the range of 0.8 or more and 1.25 or less. The aluminum blank material for press forming is characterized by being configured as described above.

  Moreover, in the preferable 2nd aspect of the aluminum blank for press molding according to this invention, the said plate-shaped aluminum base material is comprised with an Al-Mg type alloy or an Al-Mg-Si type alloy.

  Furthermore, in another advantageous third aspect of the aluminum blank for press molding according to the present invention, this blank material is used as a blank for press molding that gives a vehicle body panel of an automobile by press molding.

  Furthermore, in another desirable fourth aspect of the aluminum blank for press forming according to the present invention, the joining of the butt portions of the two plate-like aluminum base materials is realized by performing a friction stir welding operation.

In short, according to the first aspect of the aluminum blank for press forming according to the present invention, the plate thickness and tensile strength of one plate-shaped base material of two plate-shaped aluminum base materials having different plate thicknesses can be obtained. Ratio of product: t ₁ × σ ₁ and the product of thickness and tensile strength of the other plate-shaped base material: t ₂ × σ ₂ : R = (t ₁ × σ ₁ ) / (t ₂ × (sigma) ₂ ) is comprised so that it may become a value within the range of 0.8 or more and 1.25 or less, The board thickness of the plate-shaped aluminum base material with a small board thickness which gives the thin part of a blank material is The plate-like aluminum base material with a small plate thickness has the same thickness as the plate-like aluminum base material with a large plate thickness, which gives the thick part of the blank material. The plate thickness of the plate-shaped aluminum base material, which is made to be moderately larger than the tensile strength of the sheet-shaped aluminum base material and has a large plate thickness, Therefore, the tensile strength of the plate-shaped aluminum base material with a large plate thickness is more appropriate than that of the thin plate-shaped aluminum base material. The balance between the thickness and tensile strength of each base metal between the two sheet-like aluminum base materials with different thicknesses is optimized, thereby, during press molding on the blank material, The thin wall portion provided by the plate-like aluminum base material having a small plate thickness and the thick wall portion provided by the plate-like aluminum base material having a large plate thickness can be deformed substantially uniformly.

  Therefore, in the aluminum blank for press molding according to the present invention, the thin wall portion provided by the plate-like aluminum base material having a small plate thickness during the press molding has a thickness provided by the plate-like aluminum base material having a large plate thickness. It can be advantageously eliminated or suppressed that it is deformed preferentially and greatly compared to the meat part, and it is also effective that the thin part breaks more easily than the thick part. Can be avoided.

  Therefore, in the aluminum blank material for press molding according to the present invention, the thick wall portion can be sufficiently deformed along with the deformation of the thin wall portion at the time of press molding, and the ductility of the entire blank material can be improved. It can be effectively increased, whereby the amount of deformation of the entire blank during press forming can be advantageously increased. As a result, it becomes possible to perform press molding with a free press shape and a larger processing amount, and the press moldability can be improved extremely effectively.

  Further, in the second aspect of the aluminum blank for press molding according to the present invention, excellent strength derived from the Al—Mg based alloy or Al—Mg—Si based alloy is provided. Sufficient strength can be imparted to the resulting pressed product.

  Furthermore, according to the third aspect of the aluminum blank for press forming according to the present invention, high strength and rigidity are required partially in the body panel of an automobile, for example, an attachment part to which various parts are attached. The part can be given by the thick part of the blank material, which advantageously eliminates the need to attach the reinforcing material to the parts mounting part of the body panel, and reduces the number of parts of the body panel. The cost reduction due to can be effectively realized.

  Further, according to the fourth aspect of the aluminum blank for press forming according to the present invention, the joint strength at the joint can be sufficiently increased, and the fracture at the joint at the time of press molding can be effectively eliminated. Thus, an improvement in press formability can be realized even more advantageously.

  Hereinafter, in order to clarify the present invention more specifically, the configuration of an aluminum blank for press forming according to the present invention will be described in detail with reference to the drawings.

  First, in FIG. 1, as an example of an aluminum blank material for press molding having a structure according to the present invention, a tailored blank material 10 which is a press molding aluminum blank material that gives a body panel such as an inner material of an automobile has a longitudinal sectional form. In FIG. As shown in FIG. 1, the tailored blank material 10 is formed by joining the two aluminum base materials 12 and 14 having a flat plate shape to each other in a state where the two end surfaces face each other. Thus, the joint portion 16 is formed to be integrated. Although not explicitly shown in FIG. 1, the two flat aluminum base materials 12 and 14 are joined over the entire length of the abutting portion. And is formed to extend continuously along the entire length.

  And here, one aluminum base material 12 of the two flat aluminum base materials 12 and 14 which comprise such a tailored blank material 10 is more than the other aluminum base material 14 of them. The predetermined dimension is a thick thickness. Thereby, the strength and rigidity of the tailored blank material 10 are larger in the thick portion 18 made of the thick plate-like aluminum base material 12 than the thin portion 20 made of the thin plate-like aluminum base material 14 having a smaller plate thickness. The weight of the tailored blank member 10 is increased by the amount corresponding to the difference in plate thickness, and the weight of the tailored blank member 10 is reduced by the thickness of the thin portion 20. Thus, it is possible to advantageously realize a high strength or a high rigidity of a desired portion in a body panel such as an inner material of an automobile obtained by the above and a weight reduction of the entire inner material.

  The thick plate-like and thin plate-like aluminum base materials 12 and 14 that form the tailored blank material 10 are literally made of aluminum or an aluminum alloy. The type of the aluminum material to be configured is not particularly limited, and the same type or different types of aluminum or various types of aluminum may be used depending on the material and characteristics required for the target press product. It is appropriately selected from alloys.

  Among them, as a forming material of a blank material that gives a pressed product that requires excellent strength, such as the tailored blank material 10 of this embodiment that gives a body panel such as an inner material of an automobile, a thick plate and a thin plate are used. When the aluminum base materials 12 and 14 are used, as an aluminum material for providing each of the plate base materials 12 and 14, for example, an Al—Mg system (5000 series) having both sufficient strength and high press formability. ) Alloys and Al-Mg-Si (6000) alloys are preferably used.

  Further, when an aluminum alloy is used as the aluminum material for providing the thick and thin plate-like aluminum base materials 12 and 14, the non-heat treatment type alloy including the Al-Mg system as described above, the Al-Mg-Si system, etc. Any of the heat treatment type alloys can be used, but as the non-heat treatment type alloy, for example, one having a classification such as O, H1, H2, and H3 is used, while as the heat treatment type alloy, for example, Those having a classification such as O, T4, and T6 are used. As a result, the thick plate-like and thin plate-like base materials 12 and 14 have appropriate hardness, respectively, and thus the thick plate-like and thin plate-like aluminum base materials 12 and 14 are integrated. Sufficient robustness can be exhibited in a body panel such as an inner material of an automobile that is a press product of 10.

  The thick plate-like and thin plate-like aluminum base materials 12 and 14 are, for example, ingots of aluminum or aluminum alloy selected on the basis of the above-mentioned criteria are first agglomerated by a semi-continuous casting method using a normal DC method. Next, the obtained ingot is subjected to homogenization treatment, and then hot rolled to produce a hot rolled plate. Alternatively, a molten aluminum or aluminum alloy adjusted to a predetermined chemical composition may be directly produced as a continuous cast plate by a continuous casting method (CC method). Then, these hot-rolled plates or continuous cast plates are subjected to intermediate annealing treatment, cold rolling, etc., if necessary, and formed into a flat plate shape having a predetermined thickness, and then subjected to heat treatment. It is tempered according to the required quality and used as thick and thin aluminum base materials 12 and 14.

  Further, the joining method of the thick plate-like aluminum base material 12 and the thin plate-like aluminum base material 14 is not limited at all, and joining by a general melt welding method such as laser welding or arc welding is possible. Preferably, a friction stir welding method is employed. If this friction stir welding method is employed, it is possible to advantageously prevent the occurrence of joint defects in the joint portion 16 as compared with the case where the melt welding method is employed, and the joint strength is sufficiently increased, so that during press molding. The breakage at the joint 16 can be effectively eliminated.

By the way, as described above, the tailored blank material 10 of the present embodiment is formed by butt-joining the thick plate-like aluminum base material 12 and the thin plate-like aluminum base material 14 having a thinner thickness to each other. The plate-shaped differential thickness joint is lightweight and high in strength. The plate thickness of the thick plate-like aluminum base material 12 is t ₁ and the plate thickness of the thin plate-like aluminum base material 14 is t _2. These are not particularly limited, and the thickness t ₁ of the thick plate-like aluminum base material 12 that gives the thick portion 18 of the tailored blank material 10 is the strength and rigidity required in the thick portion 18. depending been appropriately determined, also, the thickness of the thin plate aluminum base material 14 to provide a thin portion 20 of the tailored blank 10: t ₂ is obtained the desired weight reduction is attained in the entire tailored blank 10 To the extent, it is about to be appropriately determined.

Then, in the tailored blank 10 of the present embodiment, in particular, thick plate thickness: the tensile strength of thick plate aluminum matrix 12 with t ₁ and sigma _1, and a thin plate thickness: t _When the tensile strength of the thin plate-like aluminum base material 14 having ₂ is σ ₂ , the product of the plate thickness and the tensile strength of the thick plate-like aluminum base material 12: t ₁ × σ ₁ and the thin plate-like aluminum base material 14 Product of sheet thickness and tensile strength: value of ratio of t ₂ × σ ₂ : R = (t ₁ × σ ₁ ) / (t ₂ × σ ₂ ) is 0.8 or more and 1.25 or less It is configured to have a value within the range, and there are extremely large features here.

That is, in this embodiment, having the above-described characteristic configuration, the plate thickness: t ₂ of the thin plate-like aluminum base material 14 is larger than the plate thickness: t ₁ of the thick plate-like aluminum base material 12. The tensile strength: σ _{2 of} the thin plate-like aluminum base material 14 is made to be appropriately larger than the tensile strength: σ _{1 of} the thick plate-like aluminum base material 12 by the amount of the thin plate-like aluminum, and the thick plate-like aluminum The tensile strength: σ ₁ of the thick plate-like aluminum base material 12 is a thin plate, so that the plate thickness: t _{1 of the} base material 12 is thicker than the plate thickness: t _{2 of the} thin plate-like aluminum base material 14. Tensile strength of the aluminum base material 14: The base materials 14 and 12 between the thin plate-like aluminum base material 14 and the thick plate-like aluminum base material 12 which are appropriately smaller than σ ₂ and have different plate thicknesses. The balance between plate thickness and tensile strength is optimized, thereby At their lamellar aluminum base member 14 and the thickness plate aluminum matrix 12, and the thin portions 20 provided respectively and the thick portion 18, at the time of press forming, so that substantially caused to uniformly deform.

  Thus, in such a tailored blank material 10, the thin-walled portion 20 is deformed preferentially and largely over the thick-walled portion 18 and is not easily broken during press molding. As a result of this deformation, the thick wall portion 18 is also sufficiently deformed, and the overall ductility including the thin wall portion 20 and the thick wall portion 18 is effectively enhanced. The amount of deformation can be advantageously increased. As a result, press forming with a free press shape and a larger processing amount is possible, and thus press formability can be improved extremely effectively.

Thus, in the tailored blank material 10 of the present embodiment, the product of the plate thickness and tensile strength of the thick plate-like aluminum base material 12: t ₁ × σ ₁ and the plate thickness and tensile strength of the thin plate-like aluminum base material 14. Product: t ₂ × σ ₂ ratio value: R = (t ₁ × σ ₁ ) / (t ₂ × σ ₂ ) is limited to a value within the above range for the first time. An improvement in press formability can be realized. Therefore, when the value of the ratio: R is a value that falls outside the above specific range, such as a value that is less than 0.8 or a value that exceeds 1.25, the expected improvement in press formability is achieved. The purpose or the effect cannot be achieved, and in that respect, in the tailored blank material 10 of the present embodiment, the product of the plate thickness and tensile strength of the thick plate-like aluminum base material 12 and the thin plate-like aluminum base plate. The value of the ratio of the thickness of the material 14 to the product of the tensile strength: R must be a value within the range of 0.8 to 1.25. Further, the value of the ratio: R is preferably set to a value in the range of 0.9 to 1.1 in order to achieve further improvement in press formability.

Here, the plate thickness of the thick plate-like aluminum base material 12 is t ₁ , its tensile strength is σ ₁ , the plate thickness of the thin plate-like aluminum base material 14 is t ₂ , and its tensile strength is σ ₂ . The product of the plate thickness and tensile strength of the thick plate-like aluminum base material 12: t ₁ × σ ₁ and the product of the plate thickness and tensile strength of the thin plate-like aluminum base material 14: t ₂ × σ ₂ The ratio value: R = (t ₁ × σ ₁ ) / (t ₂ × σ ₂ ) was specified as a value within the range of 0.8 to 1.25. When the thickness is t ₁ , the tensile strength is σ ₁ , the plate thickness of the thick aluminum plate 12 is t ₂ , and the tensile strength is σ ₂ , the plate of the thin aluminum plate 14 The product of thickness and tensile strength: t ₁ × σ ₁ and the product of the plate thickness and tensile strength of thick plate-like aluminum base material 12: t ₂ × σ ₂ : R = (t ₁ × σ _{1 ) / (t 2 × σ 2} ) is, 0 So that the specified to a value in the range of 8 to 1.25.

  Moreover, in the tailored blank material 10 of this embodiment, the value of the ratio of the product of the plate thickness and tensile strength of the thick plate-like aluminum base material 12 and the product of the plate thickness and tensile strength of the thin plate-like aluminum base material 14 : R is limited to a value within the specific range as described above, and the thickness and tensile strength of each of the base materials 12 and 14 between the thick plate-like aluminum base material 12 and the thin plate-like aluminum base material 14 In order to optimize the balance, it is necessary to adjust the tensile strength of each base material 12, 14. The adjustment of the tensile strength depends on the type of alloy that provides each base material 12, 14, etc. Various methods are appropriately employed.

  That is, for example, when the thick plate-like and thin plate-like aluminum base materials 12 and 14 are made of an Al—Mg-based alloy, the Mg content is adjusted, or before each of the base materials 12 and 14 is joined, The tensile strength of each of the base materials 12 and 14 can be adjusted by performing cold working. And when both the thick plate-like aluminum base material 12 and the thin plate-like aluminum base material 14 are in the tailored blank material 10 made of an Al-Mg alloy, the Mg content of the thin plate-like aluminum base material 14 is thick. When the Mg content of the plate-shaped aluminum base material 12 is increased, the ratio of the product of the plate thickness and the tensile strength in each base material 12 and 14: R is from 0.9 to 1.1 A value within the preferred range can be achieved.

  Further, for example, when the thick plate-like and thin plate-like aluminum base materials 12 and 14 are made of an Al—Mg—Si alloy, particularly when it is a T4 material, the temperature of the solution treatment at the time of tempering, The tensile strength of each of the base materials 12 and 14 can be adjusted by adjusting the time or performing an artificial aging treatment after tempering. Furthermore, if the O material is used, the tensile strength of each of the base materials 12 and 14 can be made the lowest.

  As described above, in the tailored blank material 10 of the present embodiment, a thick-walled portion capable of realizing high strength or high rigidity of a desired portion in a body panel such as an inner material of an automobile obtained by press molding. 18 and the thin-walled portion 20 that contributes to the weight reduction of the entire inner material, the inner material that requires light weight, for example, a part such as a mounting site where various parts are mounted It is possible to provide such a portion with the thick-walled portion 18 without attaching a reinforcing material to a portion where high strength and rigidity are required, thereby reducing the number of parts of the inner material and thereby Cost reduction can be effectively realized.

  And in this tailored blank material 10, since especially the thick part 18 and the thin part 20 are equipped with the outstanding press-formability which can be press-molded to a free shape with a uniform and big deformation amount. A body panel such as an inner material of a target automobile can be stably molded with a desired shape and excellent quality.

  In addition, in this embodiment, although the specific example of what applied this invention with respect to the aluminum blank material for press molding (tailored blank material) which gives body panels, such as an inner material of a motor vehicle, this invention is others Of course, the present invention can be advantageously applied to any other than the aluminum blank for press forming that gives various press products other than the body panel such as the inner material of the automobile.

  In addition, the present invention can be implemented in various forms, and any of various embodiments relating to various changes, modifications, and improvements of the present invention adopted based on the knowledge of those skilled in the art. It should be understood that the present invention belongs to the category of the present invention without departing from the spirit of the present invention.

  In the following, some examples of the present invention will be shown and the characteristics of the present invention will be further clarified, but the present invention is not limited by the description of such examples. Needless to say.

<Example>
First, ingots made of six types of alloys (A to F) having chemical components (component compositions) as shown in Table 1 below were cast by a semi-continuous casting method. In addition, each component of Table 1 was shown on the weight% basis.

  Thereafter, homogenization treatment is performed on each of the ingots made of the four types of alloys A to D among the six types of cast ingots (A to F) according to a conventional method. , Hot rolling, cold rolling, and annealing, and as shown in Table 2 below, it is made of any of four types of alloys (A to D) and has a plate thickness of 1.0 mm, 1 A total of 8 types of aluminum plate materials made of O material, each of 3 mm, 1.5 mm, and 2.0 mm, were prepared and prepared.

  Further, in addition to the eight kinds of aluminum plate materials made of the O material, homogenization treatment, hot rolling, cold cooling are performed on each of the ingots made of the two types of alloys E and F in accordance with a conventional method. Hot-rolling, solution treatment, and quenching are performed to make any one of the alloys E and F, two types of aluminum plate materials made of T4 material, which have a plate thickness of 1.0 mm, and any of the alloys E and F. Two types of aluminum plate materials made of T4 and having a plate thickness of 1.3 mm were prepared and prepared. In addition, among these four types of aluminum plate materials, two types of aluminum plate materials having a thickness of 1.0 mm were further subjected to artificial aging treatment at 170 ° C. for 4 hours.

  Then, the tensile strength of each of the 12 kinds of aluminum plate materials prepared in this way was measured according to JIS Z 2241. The results are also shown in Table 2 below.

Next, as shown in Table 2 below, among the 12 types of prepared aluminum plate materials, five types of aluminum plate materials having a plate thickness of 1.0 mm were used as the thin plate-like aluminum base material, while the plate thickness was 1 .7 kinds of aluminum plate materials of 3 mm, 1.5 mm, and 2.0 mm are used as thick plate-like aluminum base materials, and the thickness of the thin plate-like aluminum base material is t ₁ When the strength is σ ₁ , the thickness of the thick aluminum plate is t ₂ , and the tensile strength is σ ₂ , the product of the thickness of the thin aluminum plate and the tensile strength: t ₁ × The product of the plate thickness and tensile strength of σ ₁ and the thick plate-like aluminum base material: The value of the ratio of t ₂ × σ ₂ : R = (t ₁ × σ ₁ ) / (t ₂ × σ ₂ ) A thin plate-like aluminum base material and a thick plate-like aluminum plate having values within the range specified in the invention After selecting one type each of the um base material, the selected thick plate-like aluminum base material and thin-plate-like aluminum base material are in a state where they are butted against each other at the end faces in the length direction. The butt portion was friction stir welded to produce an aluminum blank for press molding. In this case, 13 kinds of press-molding aluminum blanks (test materials 1 to 13) having different combinations of thick plate and thin plate aluminum base materials were obtained by such a method.

In addition, the value of R in each of these 13 types of test materials 1 to 13 is shown in Table 2 below. In 13 types of test materials 1 to 13, the thickness of the thick plate-like aluminum base material is t ₁ , the tensile strength is σ ₁ , the thickness of the thin plate-like aluminum base material is t ₂ , and the tensile strength is The value of R when σ ₂ is set, that is, the reciprocal of the value of R shown in Table 2 below, is also within the scope of the present invention. Further, among the 13 types of test materials 1 to 13, when producing the test materials 1 to 5 and the test materials 10 to 13, a steel rotary tool was rotated at a rotational speed of 1000 rpm and a joining speed of 200 mm / min. Friction stir welding is carried out under the condition of horizontal movement at, and when the test materials 6 to 9 are produced, the steel rotary tool is horizontally moved at a rotation speed of 1000 rpm and a welding speed of 500 mm / min. Friction stir welding was carried out.

  And, in order to examine the press formability of the 13 types of test materials 1 to 13 thus obtained, first, from each of the test materials 1 to 13, the JIS No. 5 type test piece, the bonding line between the base materials, At the center of the test piece, each sample was cut out and produced so as to extend and be positioned in a direction perpendicular to the tensile direction in the tensile test described later. Subsequently, a tensile test was performed on the 13 types of test pieces prepared from each of the test materials 1 to 13 at normal temperature according to JIS Z 2241, and the elongation at break was measured at a distance between the gauge points of 50 mm. . The results are shown in Table 3 below.

  Moreover, apart from the test piece for measuring the elongation at break, a disc-shaped test piece having a diameter of 120 mm is used from 13 kinds of test pieces 1 to 13 so that the joint line between the base materials is located at the center of the test piece. It cut out to each and produced. And after applying a low-viscosity lubricating oil to the surface of each test piece using 13 types of test pieces and an Erichsen tester, each of which was produced one by one from these test materials 1 to 13, each of these test pieces was applied. Under the conditions of a wrinkle pressing force of 40 kN and a forming speed of 2.0 mm / s, an overhanging process using a 50 mm diameter spherical head punch was performed, and the limit forming height of each test piece was examined. At this time, a lock bead having a width of 3 mm and a height of 20.5 mm was provided over the entire circumference of the crease presser die to prevent inflow of material. The results are also shown in Table 3 below.

As is clear from the results in Table 3, all of the 13 types of test materials 1 to 13 have a large elongation value of 20% or more and a limit molding height of 16 mm or more. Thus, when the plate thickness of the thin plate-like aluminum base material is t ₁ , the tensile strength is σ ₁ , the plate thickness of the thick plate-like aluminum base material is t ₂ , and the tensile strength is σ ₂ , The product of the thickness and tensile strength of the aluminum base material: t ₁ × σ ₁ and the product of the thickness and tensile strength of the thick aluminum base material: t ₂ × σ ₂ : R = (t High press capable of being deformed with a sufficient amount of deformation during press forming of a press forming aluminum blank material in which ₁ × σ ₁ ) / (t ₂ × σ ₂ ) is a value within the range specified in the present invention. It is clearly recognized that it has moldability.
<Comparative example>
For comparison, first, an ingot made of six kinds of alloys (A to F) having the same component composition as that used in the above-described examples was cast by a semi-continuous casting method, and then this casting Among the ingots made of the six types of alloys (A to F), homogenization treatment and hot rolling are performed on each of the ingots made of the four types of alloys A to D according to conventional methods. , Cold rolling, and annealing, consisting of any of four types of alloys (A to D), and having a plate thickness of 1.0 mm, four types of aluminum plates made of O material, Four types of aluminum plates made of O material, each made of any of four types of alloys (A to D) and having a plate thickness of 1.5 mm, were prepared and prepared. In addition, homogenization treatment, hot rolling, cold rolling, solution treatment, and quenching are performed on each of the ingots made of the two types of alloys E and F according to a conventional method. Made of either of two types of alloys (E, F), two types of aluminum plate made of T4 material, with a plate thickness of 1.0 mm, and one of two types of alloys (E, F) Two types of aluminum plate materials made of T4 material having a plate thickness of 1.5 mm were prepared and prepared. Then, the tensile strength of each of the 12 kinds of aluminum plate materials prepared in this way was measured in the same manner as in the above example. The results are shown in Table 4 below.

Next, as shown in Table 4 below, among the 12 types of prepared aluminum plate materials, six types of aluminum plate materials having a plate thickness of 1.0 mm were used as the thin plate-like aluminum base material, while the plate thickness was 1 .6 mm aluminum plate with a thickness of 5 mm is used as a thick aluminum plate, and among them, the thickness of the thin aluminum plate is t ₁ and the tensile strength is σ _1. When the plate thickness of the aluminum plate is t ₂ and the tensile strength is σ ₂ , the product of the plate thickness and tensile strength of the thin plate aluminum substrate: t ₁ × σ ₁ and the thickness of the plate aluminum plate Product of plate thickness and tensile strength: Ratio value of t ₂ × σ ₂ : R = (t ₁ × σ ₁ ) / (t ₂ × σ ₂ ) is a value outside the range specified in the present invention. 1 type each of thin plate-like aluminum base material and thick plate-like aluminum base material After selection, in the state where the selected thick plate-like aluminum base material and thin plate-like aluminum base material are butted against each other at the end surfaces in the length direction, the butt portions are friction stir welded and pressed. An aluminum blank for molding was produced. Here, six kinds of press-molding aluminum blanks (test materials 14 to 19) having different combinations of thick and thin plate-like aluminum base materials were obtained by such a method.

In addition, the value of R in each of these six types of test materials 14 to 19 is shown in Table 4 below. In the six types of test materials 14 to 19, the thickness of the thick plate-like aluminum base material is t ₁ , the tensile strength is σ ₁ , the thickness of the thin plate-like aluminum base material is t ₂ , and the tensile strength is The value of R when σ ₂ , that is, the reciprocal of the value of R shown in Table 4 below, is also outside the scope of the present invention. Furthermore, in producing the six types of test materials 14 to 19, friction stir welding was performed under the conditions in which a steel rotary tool was horizontally moved at a rotational speed of 1000 rpm and a joining speed of 300 mm / min. .

  Then, in order to examine the press formability of the six types of test materials 14 to 19 thus obtained, the breaking elongation and the limit molding height of each of the test materials 14 to 19 were measured by the same method as in the above example. The results are shown in Table 5 below.

かかる表５から明らかなように、６種類の試験材１４〜１９は、何れも、破断伸びが２０％未満で、且つ限界成形高さが１６ｍｍ未満であって、前記実施例における試験材１〜１３のそれぞれの破断伸びと限界成形高さの値に比して、明らかに小さな値となっている。これは、薄板状アルミニウム母材の板厚をｔ₁ 、引張強さをσ₁ とし、且つ厚板状アルミニウム母材の板厚をｔ₂ 、引張強さをσ₂ としたときに、薄板状アルミニウム母材の板厚と引張強さの積：ｔ₁ ×σ₁ と厚板状アルミニウム母材の板厚と引張強さの積：ｔ₂ ×σ₂ との比の値：Ｒ＝（ｔ₁ ×σ₁ ）／（ｔ₂ ×σ₂ ）が本発明において特定される範囲外の値とされたプレス成形用アルミニウムブランク材が、プレス成形において劣るものであることを、如実に示しているのである。

As is clear from Table 5, all of the six types of test materials 14 to 19 had a breaking elongation of less than 20% and a limit molding height of less than 16 mm, and the test materials 1 to 1 in the above examples were used. The values are clearly smaller than the values of the respective breaking elongations and the limit molding heights. This is because when the plate thickness of the thin plate-like aluminum base material is t ₁ , the tensile strength is σ ₁ , the plate thickness of the thick plate-like aluminum base material is t ₂ , and the tensile strength is σ ₂ , The product of the thickness and tensile strength of the aluminum base material: t ₁ × σ ₁ and the product of the thickness and tensile strength of the thick aluminum base material: t ₂ × σ ₂ : R = (t _It clearly shows that an aluminum blank for press molding in which ₁ × σ ₁ ) / (t ₂ × σ ₂ ) is outside the range specified in the present invention is inferior in press molding. It is.

It is explanatory drawing which expands and shows a part of longitudinal section of an example of the aluminum blank for press molding according to this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Tailored blank material 12 Thick plate-shaped aluminum base material 14 Thin plate-shaped aluminum base material 16 Joint part 18 Thick part 20 Thin part

Claims (4)

Two plate-shaped aluminum base materials having different plate thicknesses are used in press molding, in which the butted portions are joined together while being joined to each other at their end faces. An aluminum blank material,
The plate thickness of any one of the two plate-like aluminum base materials is t ₁ , the tensile strength is σ ₁ , and the plate of the other plate-like base material is one of them. When the thickness is t ₂ and the tensile strength is σ ₂ , the product of the plate thickness of the one plate-shaped base material and the tensile strength: t ₁ × σ ₁ and the plate thickness of the other plate-shaped base material Product of tensile strength: Value of ratio with t ₂ × σ ₂ : R = (t ₁ × σ ₁ ) / (t ₂ × σ ₂ ) in a range of 0.8 or more and 1.25 or less It is comprised so that it may become. The aluminum blank material for press molding characterized by the above-mentioned.   The aluminum blank for press forming according to claim 1, wherein the plate-like aluminum base material is made of an Al-Mg alloy or an Al-Mg-Si alloy.   The aluminum blank material for press molding according to claim 1 or 2, which is used as a blank material for press molding that gives a vehicle body panel of an automobile by press molding. The aluminum blank for press forming according to any one of claims 1 to 3, wherein the joining of the butted portions of the two plate-like aluminum base materials is realized by performing a friction stir welding operation.

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