JP2001300643A - Manufacturing method of magnesium product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method by which a magnesium product of a prescribed shape is manufactured by subjecting a magnesium plate to plastic working with using a punch/die without causing a crack to the magnesium product and a flaw/scratch on a surface of the product. SOLUTION: In the method to manufacture a product of a prescribed shape by subjecting a plate of magnesium or magnesium alloy to plastic working with using a punch/die, plastic working is conducted by mounting a sheet softer than the plate on at least one surface of the punch/die in contact with the plate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a magnesium or magnesium alloy (both are collectively referred to as a magnesium material in the present specification), and more particularly, the present invention relates to a method for producing a crack in a magnesium material product. The present invention relates to a manufacturing method capable of manufacturing a magnesium material product having a predetermined shape by plastic working of a magnesium material plate without causing any damage or scratches on the surface of the product.

[0002]

2. Description of the Related Art When an iron alloy or an aluminum alloy is formed by plastic working such as press working or deep drawing, an iron alloy or an aluminum alloy having excellent plastic workability is manufactured, and the alloy is subjected to plastic working. Plastic working with improved plastic workability by cooling (low-temperature working) or heating (warm or hot working) iron or aluminum alloys during working or plastic working Or both of them are combined and plastic working is performed. Further, when a flaw generated on the surface of a plastically processed product becomes a problem, a hardened layer is formed on the surface of the material before plastic processing to prevent the flaw.

[0003] However, regarding the plastic working of magnesium material, if the plastic working method used for iron alloys and aluminum alloys is directly employed, cracks may occur in the magnesium material product, and the surface of the product may be damaged or damaged. Since abrasion may occur, not only molding is difficult, but also an inspection step and a step of correcting a flaw need to be performed, so that the cost is high. Further, if a hardened layer is formed on the surface of the magnesium material before plastic working, the original characteristics of the magnesium material as a lightweight material are lost. Furthermore, addition of a new additive element that makes separation difficult at the time of recycling may adversely affect the global environment.

[0004]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and the present invention provides a method for manufacturing a magnesium product by causing cracks or scratches or scratches on the surface of the product. It is an object of the present invention to provide a manufacturing method capable of manufacturing a magnesium material product having a predetermined shape by plastic working of a magnesium material plate using a punch and a die without using a punch and a die.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted various studies to achieve the above object, and as a result, have obtained a product having a predetermined shape by plastic working of a magnesium material plate using a punch and a die. In the manufacturing method, when a thin sheet softer than the plate is attached to at least one surface of the punch and the die in contact with the sheet and plastic working is performed, even if the surface of the soft sheet is scratched, the magnesium material product The present invention was found to be able to produce a product having no cracks and no scratches or abrasions on the surface of the product, and thus having no cracks and no scratches or abrasions on the surface.

That is, a method of manufacturing a magnesium material product according to the present invention is a method of manufacturing a product having a predetermined shape by plastically processing a magnesium material plate using a punch and a die. A thin plate softer than the plate is attached to at least one of the surfaces to perform plastic working.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The plastic working method using a punch and a die, the plastic working conditions, the type of magnesium alloy, and the like in the method for manufacturing a magnesium material product of the present invention will be specifically described below. As the plastic working method that can be employed in the manufacturing method of the present invention, any method may be used as long as it can plastically work a plate material using a punch and a die, and any product shape may be used.

In the manufacturing method of the present invention, the material of the thin sheet softer than the plate attached to at least one surface of the punch and the die that comes into contact with the magnesium sheet is under plastic working conditions with the magnesium sheet. Any material may be used as long as it is non-reactive, non-welding, and non-alloying at temperature and pressure), and is not particularly limited. For example, when the magnesium material plate is a magnesium alloy plate, it is preferable to use a thin plate of pure magnesium, pure aluminum, resin, or the like. Of course, when a resin plate is used, the temperature of the punch and die and the temperature of the magnesium material plate when performing plastic working are limited in relation to the heat resistance.

In the manufacturing method of the present invention, plastic working is carried out by attaching a thinner softer than the plate to at least one surface of the punch and the die in contact with the magnesium plate. Is applied to both surfaces of the punch and the die in contact with the magnesium material plate, and plastic working is performed, or only the surface of the punch or die that comes into contact with the surface of the plate on the product surface side after the plastic working. The plastic working may be performed by attaching. The thickness of this soft thin plate is not particularly limited, but when a soft thin plate is attached to the surface of a punch and / or die in contact with a magnesium material plate and plastic working is performed, magnesium having a desired shape and thickness is obtained. Since it is essential to obtain a material, the thickness of the soft sheet is related to the dimensions of the punch and die and the shape and thickness of the intended magnesium material.

[0010] In addition, as a method of attaching a soft thin plate,
It is also possible to form a thin plate by coating or overlaying on the surface of the punch and / or die that comes into contact with the magnesium plate, but in this case, it takes time to repair the thin plate when it is worn. On the other hand, the thin plate is formed so as to conform to the shape of the surface of the punch and / or the die in contact with the plate of magnesium material, and the formed thin plate is attached to the surface of the punch and / or the die by, for example, screws. The attachment and detachment of the thin plate becomes easy, and replacement when the thin plate becomes worn becomes easy.

In the manufacturing method of the present invention, the thickness of the magnesium material plate to be plastically worked is not particularly limited as long as the thickness can be plastically worked.
In consideration of the smoothness of the product surface after plastic working, it is generally preferable that the thickness be 5 mm or less.

In the manufacturing method of the present invention, the materials of the punch and the die used for performing the plastic working are not particularly limited. It is common to use a punch and a die made of an iron-based alloy. However, if a punch and a die made of an iron-based alloy are used for plastic working of a magnesium material plate, galling may generally occur. However, by employing the manufacturing method of the present invention, even if an iron-based alloy punch and die are used, the thin plate exists on the surface thereof, so that the plastic working can be conveniently performed.

In the manufacturing method of the present invention, in order to improve the plastic workability of a magnesium material plate during plastic working, the temperature of the punch, die and thin plate is generally set to 100 to 500 ° C. 80 temperature of magnesium plate
It is preferable to carry out plastic working at a temperature of up to 450 ° C.
However, this range is not uniformly preferable, but the preferred temperature range differs according to the material of the magnesium material plate used, the material of the thin plate, and the like, and the particularly preferred temperature range also differs. The preferable temperature range is such that a person skilled in the art can easily determine the temperature range according to the material of the magnesium plate and the material of the thin plate to be used.

In the manufacturing method of the present invention, even if the surface of a soft thin plate is scratched during plastic working, the magnesium product may be cracked, or the surface of the product may be scratched or scratched. Therefore, it is possible to produce a magnesium product having a predetermined shape without any cracks and no scratches or scratches on the surface. After a number of plastic workings, the worn sheet is removed, and the sheet is recovered, recycled into a sheet having a desired thickness, and reused.

The manufacturing method of the present invention can be applied to all kinds of magnesium and magnesium alloy sheets.
However, in order to be able to produce a magnesium product of a predetermined shape by plastic working of a magnesium material plate without cracking or scratching the product surface, magnesium material must be plastically processed. It is desirable that the property is high.

As such a magnesium material, aluminum contains 35% by mass or less, zinc 5% by mass or less,
Magnesium alloy containing at least 10 mass% of at least one selected from manganese 5 mass% or less, rare earth metal 5 mass% or less, silicon 5 mass% or less and silver 5 mass% or less, with the balance being essentially magnesium , Specifically A
Z31, AZ61, AZ80 and the like.

Also, zinc 5% by mass or less, silver 5% by mass or less, rare earth metal 5% by mass or less, zirconium 1% by mass or less, manganese 1% by mass or less, calcium 5% by mass or less
5% by mass or less of silicon, at least one member selected from 5% by mass or less of yttrium, and a total of 10% by mass or less,
Magnesium alloy, the balance being essentially magnesium,
Specifically, there are ZK60, ZE10 and the like.

In the production method of the present invention, the crystal grain size in the above magnesium alloy is preferably 50 μm or less in order to further improve formability and plastic workability. When the crystal grain size in the magnesium alloy is 20 μm or less, since the magnesium alloy shows superplasticity,
In this case, superplastic working becomes possible.

Furthermore, lithium is contained in an amount of 7 to 16% by mass,
5% by mass or less of aluminum, 5% by mass or less of zinc, 5% by mass or less of calcium, 5% by mass or less of rare earth metal and 5% by mass or less of silicon in total of 10%
Magnesium alloy containing not more than 1% by mass and the balance essentially magnesium, specifically Mg-9.5Li-1Z
n. It is desirable that these lithium-containing magnesium alloys also have a small crystal grain size. However, the crystal structure of these lithium-containing magnesium alloys is bcc (body-centered cubic) excellent in plastic workability or h is poor in plastic workability.
Since it has a two-phase structure of cp (dense hexagonal) and bcc, the structure is different from that of other magnesium alloys having only the hcp structure. It doesn't have to be as problematic as magnesium alloys.

[0020]

The present invention will be specifically described below based on examples and comparative examples. Examples 1 to 18 and Comparative Examples 1 to 5 A punch support with a cartridge heater inside and a die support with a cartridge heater inside were attached to an Amsler universal test apparatus. As shown in FIG. 1, a punch 2 made of a material shown in Table 1 was attached to a punch support 1, and a die 4 made of a material shown in Table 1 was attached to a die support 3. The shape of the punch is 77mm x 77mm
With a height of 10 mm and a die shape of 80 mm x 80 m
m and a depth of 10 mm. The shape of the punch used in the drawing of a 4.5 mm thick magnesium material plate was 77 mm × 77 mm and 15 mm in height, and the shape of the die was 87 mm × 87 mm and 15 mm in depth. As shown in FIG. 1, thin plates 5 having the materials and thicknesses shown in Table 1 were attached to both surfaces of the punch and the die.

The materials and crystal grain sizes (average values) shown in Table 1
A magnesium material plate having a thickness of 120 mm × 120 mm is used, boron nitride (BN) is used as a lubricant, and the temperature of the magnesium material plate, the temperature of the punch, the die, and the thin plate are set to the first.
The temperature was adjusted to the temperature shown in the table, and drawing was performed at a molding speed of 10 mm / min. The obtained molded product was examined for cracks and scratches on the surface, and a pass product or a reject product was determined. This drawing was repeated 30 times. However, when a rejected product occurred, the subsequent drawing was stopped. Table 1 shows the number of times of drawing in which a good product was obtained (the number of times of drawing before the drawing in which a rejected product occurred). In addition, when a pass product was obtained even when the drawing process was repeated 30 times, it was described as “> 30 times”.

The meanings of the symbols in Table 1 are as follows. AZ31 = Mg-3Al-1Zn alloy material AZ61 = Mg-6Al-1Zn alloy material ZK60 = Mg-6Zn-0.6Zr alloy material LZ101 = Mg-9.5Li-1Zn alloy material A2024 = Al-4.4Cu-1. 5Mg-0.6M
n alloy material S45C = carbon steel material for machine structure specified by JIS G 4051 SKD8 = alloy tool steel material specified by JIS G 4404

[0023]

[Table 1]

As is evident from the data in Table 1, in the manufacturing method of the present invention described in Examples 1 to 18, the same thin plate can be drawn 30 times or more while the same thin plate remains. In the case of Comparative Examples 1 to 5 in which no thin plate was used, scratches were generated from the first drawing, and the products were rejected.

[0025]

By adopting the method for manufacturing a magnesium material product of the present invention, the magnesium material product can be subjected to a predetermined process by plastic working of a magnesium material plate without causing cracks or scratches on the product surface. It has become possible to produce shaped magnesium products, and it has become possible to produce high quality magnesium products at lower cost.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a drawing apparatus used in Examples and Comparative Examples.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Punch support 2 Punch 3 Die support 4 Die 5 Thin plate

Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court II (Reference) C22C 23/02 C22C 23/02 (72) Inventor Kohei Kubota 1333-2 Hara-shi, Ageo-shi, Saitama Mitsui Kinzoku Mining Co., Ltd. In-house F-term (reference) 4E050 JA01 JA08 JC02 JD03

Claims (8)

[Claims] 1. A method of manufacturing a product having a predetermined shape by plastically processing a magnesium or magnesium alloy plate using a punch and a die, wherein at least one surface of the punch and the die that comes into contact with the plate is provided with the plate. A method for producing a magnesium material product, wherein a plastic work is carried out by attaching a soft thin plate. 2. The method according to claim 1, wherein a soft thin plate is detachably attached. 3. The method according to claim 1, wherein the thickness of the magnesium or magnesium alloy plate is 5 mm or less, and the material of the punch and the die is an iron-based alloy. 4. The temperature of the punch, die and sheet is 100 to 5
The method according to claim 1, wherein the plastic working is performed at a temperature of 00 ° C. and a temperature of the magnesium or magnesium alloy plate at 80 to 450 ° C. 5. 5. An alloy containing 35% by mass or less of aluminum, 5% by mass or less of zinc, 5% by mass or less of manganese, and 5% by mass of rare earth metal.
It is characterized in that a sheet of a magnesium alloy containing at least one selected from the group consisting of at least one selected from the group consisting of at most 1 mass%, at most 5 mass% of silicon and at most 5 mass% of silver and at most 10 mass%, with the balance being essentially magnesium, is plastically processed. The production method according to any one of claims 1 to 4, wherein 6. Zinc 5% by mass or less, silver 5% by mass or less, rare earth metal 5% by mass or less, zirconium 1% by mass or less, manganese 1% by mass or less, calcium 5% by mass or less, silicon 5% or less
A sheet of a magnesium alloy containing at least one member selected from the group consisting of not more than 5% by mass and not more than 5% by mass of yttrium in a total amount of not more than 10% by mass, and the balance being essentially magnesium, is subjected to plastic working. 5. The production method according to any one of items 4. 7. The crystal grain size in a magnesium alloy is 50 μm.
7. The method according to claim 5, wherein: 8. The composition contains 7 to 16% by mass of lithium, 5% by mass or less of aluminum, 5% by mass or less of zinc, and 5% by mass of calcium.
Mass% or less, rare earth metal 5 mass% or less and at least one element selected from silicon 5 mass% or less is 10 mass% in total.
The method according to any one of claims 1 to 4, wherein a plate of a magnesium alloy containing below and essentially magnesium is plastically worked.