JP2009012041A - Warm-forming method and warm-formed article manufactured by the method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a warm-formed article having high strength by using an Al-Mg alloy having high strength. <P>SOLUTION: An Al-Mg alloy plate 6 having high strength is placed on a wrinkle presser 3 while keeping a space 7 between a die 2 and the wrinkle presser 3, and heated to the temperature range not reaching an O material. Since the plate is formed by a punch 4 while being held by the die 2 and the wrinkle presser 3, expansion is not prevented by the space and any distortion is not generated even when the Al-Mg alloy plate 6 is expanded when the plate is heated. Further, since the heating is performed for a short time, the degradation of the strength is minimum, and a warm-formed article having high strength can be obtained. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a warm forming method of an Al alloy, particularly an Al-Mg alloy, and a formed product manufactured by the warm forming method.

  Conventionally, when trying to obtain a molded product of high-strength Al alloy, the shape of the molded product is complicated, heat treatment is performed after molding, or the molding material has high strength such as Al-Mg alloy There are molding methods such as using materials.

However, in the above molding method, if the shape of the molded product is complicated to increase the strength, the appearance of the molded product is restricted.
In addition, in the case where heat treatment is performed after the forming process, Al alloys that can be used for the forming process are limited, and distortion may occur due to the heat treatment after the forming process. As a result, the yield of the molded product decreases, and the manufacturing cost of the molded product increases due to the addition of the heat treatment step. Further, the strength obtained by heat treatment of the molded product is limited to the semi-hardness of the tempering.
And when using a high-strength Al alloy such as an Al-Mg alloy as the molding material, the cold forming process cannot expect the extensibility of the molding material, and there are limits to applying complex shapes and deep drawing. is there. In addition, the molded product and the mold are easily damaged during the molding process.

  Therefore, after using a high-strength Al alloy such as an Al—Mg alloy as a forming material, a forming method in which the forming material is heated in a warm temperature range that does not reach the O material during the forming process (Patent Documents 1 and 2). And 3) have been proposed.

  However, in the drawing forming process including, for example, a die, a wrinkle presser and a punch, heating is performed while sandwiching the periphery of the molding material by the die and the wrinkle presser. As a result, due to the large linear expansion coefficient, the Al alloy molding material may generate strain that leads to deformation of the molded product at the periphery held by the die and the wrinkle retainer.

JP-A-4-158937 JP 7-310137 A JP 2006-205244 A

  The invention of the present application minimizes a decrease in strength when performing warm forming using a high-strength Al alloy molding material, and prevents deformation of the molded product, so that a high-strength molded product is obtained. To be obtained.

In order to solve the above problems, as a first feature, in a warm forming apparatus including a die, a crease presser, and a punch that are in contact with each other and have a built-in heater,
Between the dice and the crease presser that are separated from each other in the warm forming processing device, while having a gap between the dies and the crease presser, a molding material of Al-Mg alloy is formed on the other crease presser or die. A process of placing;
A step of heating the molding material to a temperature range of 180 to 350 ° C. that does not reach O material by heating the inside of the warm molding processing apparatus;
Sandwiching the molding material with a die and a crease press;
And forming a molding material sandwiched between the die and the wrinkle presser by a punch.

  As described above, even if the Al—Mg alloy, which is a molding material having a large linear expansion coefficient, expands greatly during heating, the expansion of the molding material is allowed by the gap formed between the die and the wrinkle retainer. Therefore, generation | occurrence | production of the distortion of a molded product can be prevented in the said Al-Mg alloy.

And since the Al-Mg alloy which is a forming material is in a temperature range of 180 to 350 ° C. which does not reach the O material by heating, the extensibility of the Al—Mg alloy is improved several times compared to normal temperature. As a result, the molding process becomes easy, and a complicated shape and deep drawing can be performed. Furthermore, since it is in the warm temperature range, the molded product does not reach the O material, and a sufficient strength can be ensured.
Here, the heating with respect to the forming material is preferably performed in a temperature range of 230 to 350 ° C. in the Al—Mg alloy. The present invention relates to an Al—Mg alloy. When the molding material is 1000 series, it is 180 to 300 ° C., 3000 series is 200 to 330 ° C., and 6000 series is 180 to 330 ° C. Is preferred.

  Further, based on the first feature, as a second feature, the time from the start of heating in the warm molding apparatus to the removal of the molded product is set to 2 to 30 seconds.

As described above, since the heating of the Al—Mg alloy in the warm forming apparatus is the minimum necessary, it is possible to prevent the strength of the formed product from being lowered due to the annealing generated by excessive heating. In addition, the working time of the molding process is shortened, so the temperature drop of the molding material is minimized, and the extensibility of the molding material during the molding process can be secured sufficiently, enabling complex shapes and deep drawing become.
Here, if the time from the start of heating in the warm molding apparatus to the removal of the molded product is less than 2 seconds, unevenness in the temperature distribution of the molding material is likely to occur, and the entire surface of the molding material is sufficient during the molding process. May not be able to ensure proper extensibility. On the other hand, if the time is 30 seconds or more, the molded product may be softened and deformed.

  Here, the heating to the forming material is sufficient if the temperature reaches a temperature range where the Al—Mg alloy does not reach the O material. Therefore, not only heating in the warm forming apparatus, but also heating in advance by using induction heating or hot press, the heating time in the forming apparatus is shortened, and the working time of the forming process is reduced. It can be shortened.

  And based on the 1st and 2nd characteristics, content of Mg in the said shaping | molding raw material shall be 3-10 mass% as a 3rd characteristic.

  As described above, when the content of Mg in the Al—Mg alloy, which is a molding material, is 3 to 10 mass%, a molded product with sufficient strength can be obtained. If the content of Mg contained in the molding material is less than 3 mass%, the strength of the molded product cannot be sufficiently ensured. On the other hand, if the Mg content exceeds 10 mass%, casting cracks occur due to segregation of Mg in the molding material, and ingot formation becomes difficult, making it impossible to obtain a molding material.

  By the way, the tempering for the Al—Mg alloy as the molding material is also H14, H16 or H18 in the case of work hardening in order to sufficiently secure the strength of the molded product, and in the case of moderate softening after work hardening. For example, H24, H26 or H28, and H34, H36 or H38 in the case of stabilizing after work hardening are preferable.

  The present invention uses a high-strength Al alloy as a molding material to prevent deformation and a decrease in strength due to warm forming, as well as enable complex shapes and deep drawing, The molded product has an excellent effect that it can have a high strength without deformation.

Examples of the present invention will be described below.
In addition, this Example is for demonstrating one preferable embodiment of this invention, Comprising: This invention is not restrict | limited by this.

  Therefore, as an example, the molded product 8 was manufactured based on the warm molding method of the present invention. Here, as shown in FIG. 1, the warm forming apparatus 1 that performs the warm forming method of the present invention abuts the die 2 containing the heater 5 above the wrinkle presser 3 containing the heater 5. A punch 4 that includes a heater 5 that is molded into a predetermined shape with respect to an Al-Mg alloy plate 6 that is a molding material that is placed between the die 2 and the wrinkle presser 3 in contact with the die 2 and the die 2 and The wrinkle presser 3 is arranged so as to be movable in the vertical direction from below. Here, although the die 2 is disposed above the wrinkle retainer 3 in the warm forming apparatus 1, the wrinkle retainer 3 may be disposed above the die 2. The punch 4 is arranged so as to be movable in the vertical direction from below, but may be movable in the vertical direction from above. Further, the punch 4 is movable with respect to the Al—Mg alloy plate 6 of the molding material sandwiched by the die 2 and the wrinkle presser 3, but conversely, the molding material sandwiched by the die 2 and the wrinkle presser 3 with respect to the punch 4. The Al—Mg alloy plate 6 may be movable.

  In addition, in order to be able to take out the molded product 8 smoothly and reliably, it is necessary to smooth the surfaces of the die 2, the wrinkle presser 3 and the punch 4 of the warm forming apparatus 1. Therefore, it is preferable to perform surface treatment such as chromium plating, nitriding treatment or DLC (diamond-like carbon) treatment having heat resistance and lubricity on the surfaces of the die 2, the wrinkle presser 3 and the punch 4.

  The Al-Mg alloy plate 6 of the molding material is JIS 5182-H18 (Mg: 4.5 mass%) having a thickness of 0.8 mm, and is a square tube having a height of 50 mm, a width of 60 mm, and a length of 80 mm. A drawn molded article 8 having a shape was manufactured.

That is, in the warm forming apparatus 1,
First, between the dice 2 and the wrinkle presser 3 that are spaced apart from each other (see FIG. 2A), the Al-Mg alloy plate 6 is placed on the wrinkle presser 3 while having a gap 7 between the die 2 and the wrinkle presser 3. It was mounted (see FIG. 2 (B)).
Next, while heating to 200-300 degreeC with the heater 5 which contains this die | dye 2, the wrinkle presser 3, and the punch 4 which comprise this warm forming apparatus 1, this Al-Mg alloy plate 6 is 270 +/- 20. Heated to a temperature range of ° C.
Thereafter, the Al—Mg alloy plate 6 was sandwiched between the die 2 and the wrinkle presser 3. As a result, the temperature distribution of the die 2 and the wrinkle retainer 3 and the Al—Mg alloy plate 6 sandwiched between the die 2 and the wrinkle retainer 3 became uniform.
Thereafter, the punch 4 is moved upward with respect to the Al-Mg alloy plate 6 sandwiched between the die 2 and the wrinkle presser 3 (see FIG. 2 (c)), and a predetermined shape without deformation is formed. A molded product 8 was obtained [see FIG. 2 (d)].
In the warm molding method, the time from the start of heating in the warm molding apparatus 1 to the removal of the molded product 8 was within 30 seconds.

Therefore, a tensile test specified in JIS was performed on the molded product 8 obtained by the warm molding method of the present invention, and the yield strength was measured. As a result, the yield strength of the molded product 8 is 250 to 300 N / mm ² , and the decrease in the yield strength can be kept within 10% even when compared to the yield strength of the Al—Mg alloy plate 6 before the molding process. It was.

On the other hand, when a drawn product having the same shape as the above embodiment is manufactured by cold forming, 1100-H24 or 5052-H32 is the limit for the material and tempering of the Al alloy as the forming material.
Therefore, as a comparative example with respect to the embodiment of the present invention, 1050-H24 and 5052-H32 are used for the Al alloy plate of the forming material, and the drawing height of the same shape as the above embodiment is based on the warm forming method of the present invention. A molded product having a thickness of 50 mm was produced. As a result, strength of the molded article, the strength becomes 1050-H24 in 100N ^/ mm 2, 5052-H32 in 150 N / mm ² is low, significantly reduced even in comparison with strength of the molding material before molding It was confirmed.

  Therefore, in the molded product 8 produced by the warm molding method of the present invention, a molded product produced by warm molding using 1050-H24 and 5052-H32 Al alloy plates as the molding material, and If it is sufficient if the same strength can be ensured, in the present invention, the thickness of the Al—Mg alloy plate 6 as a forming material can be reduced to about 2/3 to 1/2. As a result, the molded product 8 of the present invention can be reduced in weight, and the manufacturing cost can be reduced.

  The present invention can be widely applied in warm forming using a high-strength Al—Mg alloy.

It is a schematic diagram which shows the structure of the warm forming apparatus provided to the warm forming method of this invention. It is the schematic diagram which showed the manufacturing process of the molded product by the warm forming method of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Warm forming apparatus 2 Dice 3 Wrinkle holding | suppressing 4 Punch 5 Heater 6 Al-Mg alloy board 7 Cavity 8 Molding processed goods

Claims (4)

In a warm forming apparatus equipped with a die, a wrinkle presser and a punch that can come into contact with each other and have a built-in heater,
Between the dice and the crease presser that are separated from each other in the warm forming processing device, while having a gap between the dies and the crease presser, a molding material of Al-Mg alloy is formed on the other crease presser or die. A process of placing;
A step of heating the molding material to a temperature range of 180 to 350 ° C. that does not reach O material by heating the inside of the warm molding processing apparatus;
Sandwiching the molding material with a die and a crease press;
A warm forming method comprising: forming a molding material sandwiched between the die and the wrinkle press with a punch. 2. The warm forming method according to claim 1, wherein the time from the start of heating in the warm forming apparatus to the removal of the formed product is 2 to 30 seconds. The warm forming method according to claim 1 or 2, wherein the content of Mg in the molding material is 3 to 10 mass%. A molded article manufactured by the warm molding method according to any one of claims 1 to 3.

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