WO2004085689A1

WO2004085689A1 - Magnesium alloy of high strength and high toughness and method for production thereof

Info

Publication number: WO2004085689A1
Application number: PCT/JP2004/004201
Authority: WO
Inventors: Yoshihito Kawamura
Original assignee: Yoshihito Kawamura
Priority date: 2003-03-25
Filing date: 2004-03-25
Publication date: 2004-10-07
Also published as: JPWO2004085689A1

Abstract

A magnesium alloy having high strength and high toughness which is produced by providing a molten alloy comprising a atomic % of Zn, b atomic % in total of at least one rare earth element selected from the group consisting of La, Ce and Mm, the balance being Mg, with the proviso that a and b satisfy the following formulae (1) to (3): (1) 0.2 ≤ a ≤ 3.0, (2) 0.3 ≤ b ≤ 1.8, (3) -0.2a + 0.55 ≤ b ≤ -0.2a + 1.95, and solidifying the molten metal through rapid cooling, and has a lathing structure comprising cells or grains and, formed therein, fine spherical compounds having a particle diameter of 50 nm or less; and a method for producing the magnesium alloy. The magnesium alloy exhibits both the strength and toughness sufficient to be practically used in applications of a magnesium alloy being currently expanded.

Description

High strength and high toughness magnesium alloy and its manufacturing method 1. Technical field

The present invention relates to a high-strength, high-toughness magnesium alloy and a method for producing the same, and more particularly, to a high-strength, high-toughness magnesium alloy which achieves high-strength, high-toughness by containing a specific rare earth element in a specific ratio, and its production. About the method.

Rice field

2. Background technology

Magnesium alloys, along with their recyclability, have begun to spread rapidly as housings for mobile phones and laptops or as automotive parts.

For these applications, magnesium alloys are required to have high strength and high toughness. Various studies have been made on the production of high-strength, high-toughness magnesium alloys in terms of materials and manufacturing methods.

On the manufacturing side, rapid solidification powder metallurgy (RS-P /

M) method was developed, and a magnesium alloy with a strength of about 40 OMPa, which is about twice that of the forged material, has been obtained.

As magnesium alloys, Mg-A1 system, Mg-Al-Zn system, Mg_Th-Zn system, Mg_Th-Zn-Zr system, Mg-Zn_Zr system, Mg-Zn-Zr-RE (Rare earth element) alloys such as those based on components are known. When magnesium alloys having these compositions are manufactured by the RS-P / M method, the strength is higher than when manufactured by the sintering method, but the strength is still insufficient, or the toughness (ductility) is insufficient even if the strength is sufficient. There was a drawback that it was insufficient and was difficult to use for applications requiring high strength and high toughness.

As these high strength and high toughness magnesium alloys, Mg_Zn

-RE (rare earth element) alloys have been proposed (for example, Japanese Patent No. 3238516, Japanese Patent No. 2807374, Japanese Patent Application Laid-Open No. 2002-256370). 3. Disclosure of the invention

However, in conventional Mg-Zn-RE alloys, high-strength magnesium alloys are obtained by heat-treating, for example, amo / fus-like alloy materials and fine crystallization. There is a preconception that considerable amounts of zinc and rare earth elements are required to obtain the amorphous alloy material. Magnesium alloys containing relatively large amounts of zinc and rare earth elements have been used.

For example, the magnesium alloy described in Japanese Patent No. 3238516 is a Mg—Zn—RE alloy, and uses Y, Ce, La, Nd, Pr, Sm and Mm (misch metal) as rare earth elements. The minimum value of the rare earth element content is 1.0 to 2.0 atomic% as shown in FIG. The rare earth element actually used in Examples and Comparative Examples was only Mm, and the minimum value was 1 atomic% as shown in Tables 2 and 3, and the zinc content at that time was 2 to 10%. Atomic%.

Similarly, Japanese Patent No. 2807374 discloses an Mg-Zn (or Ni, Cu) -RE alloy, and the content of rare earth elements is limited to 1 to 20 atomic%. The rare earth element actually used in the examples is also Mm in Patent No. 2807374, and the minimum value is 1 atomic% in Examples 7 and 13; Is only 1 atomic%. Zinc content of the magnesium alloy of Example 7 is 5 atomic ^_0/0, the sum of the alloy components other than mug Neshiumu has a 6 atom%.

Japanese Patent No. 3238516 and Japanese Patent No. 2807374 disclose that high strength and high toughness have been obtained. However, there are almost no alloys that have practically achieved both strength and toughness. Further, at present, applications of magnesium alloys are expanding, and conventional strength and toughness are insufficient, and magnesium alloys having higher strength and toughness are demanded.

Further, Japanese Patent Application Laid-Open No. 2002-256370 discloses that a rare earth element contains 0.5 atom. / _{0 to} 5 atomic%, at least one of zinc and aluminum is 0.2 atomic% More than 4 atoms. / ₀ or less contained respectively, are Ma Guneshiumu alloys disclosed have a long period hexagonal structure further into the crystal. The composition range of the rare earth element in Japanese Patent Application Laid-Open No. 2002-256370 is set to be 0.5 atomic% or more and 5 atomic% or less, but in Examples 1 to 6, the rare earth element has 2 atoms. It is fixed at / ₀ and its usefulness in other composition ranges has not been proven. Still more 5 atomic ^_0/0 0. lower limit of the rare earth element content because if the "content is 0.5 less than 5 atomic%, it is impossible to obtain a long period six-way structure of the present invention The strength of the alloys is so low that they cannot be put to practical use. ”The range of rare earth elements contained in JP-A-2002-256370 is specific to magnesium alloys having a long-period hexagonal structure, and is relatively broad. Data is provided for only one rare earth element content range. The present invention has been made in view of the above-described circumstances, and has as its object to provide a high-strength high-toughness magnesium alloy and a high-strength and toughness magnesium alloy which are practically used in both strength and toughness for an expanded use of a magnesium alloy. It is to provide a manufacturing method.

In order to solve the above-mentioned problems, a high-strength and toughness magnesium alloy according to the present invention contains Zn and & atomic%, and has at least one rare earth element selected from the group consisting of La, Ce and Mm. The element contains a total of b atomic% and the balance consists of Mg. A and b satisfy the following equations (1) to (3).

(1) 0.2≤a≤3.0

(2) 0.3 ≤b≤ l. 8

(3)-0.2 a + 0.5 5 ≤ b ≤-0.2 a + 1.95

It is more preferable to use the following formula (4) instead of the above formula (3). That is, it is more preferable that the above a and b satisfy the above equations (1) and (2) and the following equation (4).

(4) — 0.2 a + 0.5 5 ≤ b ≤-0.2 a + 1.80

Here, Mm (Misch metal) is a mixture or alloy of a plurality of rare earth elements mainly composed of Ce and La.

This is the residue after Nd etc. has been refined, and its composition depends on the composition of the ore before refinement. Dependent.

High strength髙靱resistance Maguneshiumu alloy according to the present invention, a Z n contains% a atom, L a, b atomic ^_0/0 containing in total of at least one rare earth element selected from the group consisting of C e and Mm And Si, Gd, Dy, Tb, Ho, Er, Ca, Mn, Ag, Li, Zr, Th, Y, Yb, Eu, Pr, 3111 and (group consisting of 1) At least one metal selected from the group consisting of more than 0 atomic% and 1.8 atomic% or less, with the balance being Mg, and a and b satisfy the following formulas (1) to (3).

(1) 0.2≤a≤3.0

(2) 0.3 ≤b≤ l. 8

(3)-0.2 a + 0.55 ≤ b ≤ 0.2 a + 1.95

(4)-0.2 a + 0.5 5 ≤ b ≤-0.2 a + 1.80

Each of the high-strength and toughness magnesium alloys according to the present invention is useful as an alloy for use in high-tech equipment that requires high performance in both strength and toughness, and La, Ce, and Mm are rare earth elements. It is inexpensive in the inside, and also advantageous in terms of cost.

The high-strength high-toughness magnesium alloy according to the present invention contains Zn at & atomic%, and contains b atomic% in total of at least one rare earth element selected from the group consisting of La, Ce and Mm, The balance is made of Mg, and a and b are quenched solids after quenching and solidifying a molten metal satisfying the following equations (1) to (3).

In the rapidly solidified product, an intermetallic compound having a particle size of 100 nm or less is precipitated in a cell or a crystal grain. More specifically, it has a lath-like structure having a fine spherical compound with a particle size of 50 nm or less.

(1) 0.2≤a≤3.0

(2) 0.3 ≤ b≤ 1.8 (3) -0.2a + 0.55≤b≤-0.2a + 1.95 It is more preferable to use the following equation (4) instead of the above equation (3). That is, it is more preferable that the above a and b satisfy the above equations (1) and (2) and the following equation (4).

(4) -0.2 a + 0.5 5≤b≤- 0.2 a + 1.80

High strength and high toughness magnesium alloy according to the present invention, Z n the containing% a atom, L a, C e及b atom in total of at least one rare earth element selected from the group consisting of Pi Mm ^_0/0 Contains, Si, Gd, Dy, Tb, Ho, Er, Ca, Mn, Ag, Li, Zr, Th, Y, Yb, Eu, Pr, Sm and Nd The total content of at least one metal selected from the group is more than 0 atomic% and 1.8 atomic% or less, the balance being Mg, and a and b satisfy the following formulas (1) to (3). A rapidly solidified product after solidification,

(1) 0.2≤a≤3.0

(2) 0.3 ≤ b≤ 1.8

(3)-0.2 a + 0.5 5 ≤ b ≤-0.2 a + 1.95

(4) One 0.2 a + 0.5 5 ≤ b ≤-0.2 a + 1.80

Each of the high-strength and toughness magnesium alloys according to the present invention is useful as an alloy for high-tech equipment requiring high performance in both strength and toughness, and La, Ce and Mm are rare earth elements. It is inexpensive inside, and is cost-effective.

The reason why the content of zinc is set to 3.0 atomic% or less is that if it exceeds 3.0 atomic%, toughness (or ductility) tends to be particularly reduced. Also, rare The reason why the content of the earth element is set to 1.8 atomic% or less is that if it exceeds 1.8 atomic%, the toughness (or ductility) tends to decrease particularly.

The reason why the content of zinc is set to 0.2 atomic% or more is that if it is less than 0.2 atomic% / ₀ , at least one of strength and toughness becomes insufficient. The reason why the content of the rare earth element is 0.3 atomic% or more is that if the content is less than 0.3 atomic%, at least one of strength and toughness becomes insufficient.

The increase in strength and toughness, especially the toughness is remarkable when the rare earth element content is 0.5 to 1.5 atomic%. In the case of zinc, the increase in strength and toughness becomes remarkable at 0.5 to 2.0 atomic%. When the zinc content is around 0.5 atomic%, the strength tends to decrease as the content of the rare earth element decreases, but even in this range, the strength and toughness are higher than before.

Also selected from the group consisting of Si, Gd, Dy, Tb, Ho, Er, Ca, Mn, Ag, Li, Zr, Th, Y, Yb, Eu, Pr, Sm and Nd By containing at least one kind of metal in total of more than 0 atomic% and 1.8 atomic% or less, other properties can be improved while maintaining high strength and toughness. The high-strength, high-toughness magnesium alloy according to the present invention contains Zn at a atomic%, and contains at least one rare earth element selected from the group consisting of La, Ce and Mm in a total of 13 atomic%, The remainder consists of Mg, and a and b are quenched and solidified melts satisfying the following formulas (1) to (3) to form quenched solids, and are plastically worked products after plastic quenching of the quenched solids. So,

In the plastically worked product, an intermetallic compound having a particle size of 100 nm or less is precipitated in a cell or a crystal grain. More specifically, it has a lath-like structure having a fine spherical compound with a particle size of 50 nm or less.

(1) 0.2 ≤ a ≤ 3.0

(2) 0.3 ≤ b≤ 1.8

(3)-0.2 a + 0.55 ≤ b≤-0.2 a + 1.95

It is more preferable to use the following formula (4) instead of the above formula (3). That is, It is more preferable that the a and b satisfy the above formulas (1) and (2) and the following formula (4). '

(4) One 0.2 a + 0.5 5 ≤ b ≤-0.2 a + 1.80

High strength and high toughness magnesium alloy according to the present invention, a Z n contains% a atom, L a, b atomic ^_0/0 containing in total of at least one rare earth element selected from the group consisting of C e and Mm From the group consisting of Si, Gd, Dy, Tb, Ho, Er, Ca, Mn, Ag, Li, Zr, Th, Y, Yb, Eu, Pr, Sm and Nd. The total content of at least one selected metal is more than 0 atomic% and 1.8 atomic% or less, and the balance consists of Mg, and a and b satisfy the following formulas (1) to (3). Forming a rapidly solidified product by performing plastic working on the rapidly solidified product,

In the plastically processed product, an intermetallic compound having a particle size of 100 nm or less is precipitated in a cell or a crystal grain. More specifically, it has a lath-like structure having a fine spherical compound with a particle size of 50 nm or less.

(1) 0.2≤a≤3.0

(2) 0.3 ≤ b≤ 1.8

(3) One 0.2 a + 0.5 5 ≤ b ≤-0.2 a + 1.95

(4)-0.2 a + 0.5 5 ≤ b ≤-0.2 a + 1.80

In the high-strength and high-toughness magnesium alloy according to the present invention, it is preferable that the plastic deformation is any one of extrusion, rolling, ECAE (equal-channel-angular-extrusion), and forging.

In the high-strength and high-toughness magnesium alloy according to the present invention, the rare earth element may be La or Ce.

In the high-strength, high-toughness magnesium alloy according to the present invention, the cooling rate at the time of rapidly solidifying the molten metal is preferably 3.5 × 10 ⁴ K ns or more. Good. This is because if the cooling rate is less than 3.5 × 10 ⁴ K / sec, the toughness of the magnesium alloy decreases.

Further, in the high-strength and high-toughness magnesium alloy according to the present invention, it is more preferable that the cooling rate when rapidly solidifying the molten metal is 7 × 10 ⁴ KZ seconds or more.

Further, in the high-strength and high-toughness magnesium alloy according to the present invention, it is preferable that the intermetallic compound, for example, the spherical compound is a Mg-—η-rare earth element-based precipitate.

In the high-strength and high-toughness magnesium alloy according to the present invention, a segregation layer having a thickness of 100 nm or less may be present at a boundary of the cells or a crystal grain boundary. The reason why the thickness of the segregated material segregating at the cell boundary or grain boundary is 100 nm or less is that when a segregated material having a thickness of more than 100 nm segregates at the cell boundary or the grain boundary, it becomes brittle. This is because high toughness cannot be obtained.

It is preferable that Mg, Zn, and a rare-earth element system be present in the biased layer.

In the high-strength and high-toughness magnesium alloy according to the present invention, the total volume fraction of the intermetallic compound (for example, spherical compound) and the segregation layer is preferably 3.6% or more and 17% or less.

In the above-described high-strength and high-toughness magnesium alloy according to the present invention, the total content of rare earth elements may be 1.8 atomic% or less. In the high-strength and high-toughness magnesium alloy according to the present invention, the width of the cell or the crystal grain may be 500 nm or less.

The method for producing a high-strength, high-toughness magnesium alloy according to the present invention comprises: a) containing at least one atomic% of Zn, and at least one rare earth element selected from the group consisting of La, Ce, and Mm in a total containing atomic%, and the balance of Mg, a and b the following formula (1) to (3) the melt satisfying, 3. 5 X 1 0 ⁴ rapidly solidified product is rapidly solidified by the KZ seconds or more cooling rate Is provided.

(1) 0.2≤a≤3.0 (2) 0.3 ≤b≤ l. 8

(3)-0.2 a + 0.5 5 ≤ b ≤-0.2 a + 1.95

(4) One 0.2 a + 0.5 5 ≤ b ≤-0.2 a + 1.80

The method for producing a high-strength, high-toughness magnesium alloy according to the present invention includes the step of: containing at least one atomic% of Zn; . /. Containing, Si, Gd, Dy, Tb, Ho, Er, Ca, Mn, Ag, Li, Zr, Th, Y, Yb, Eu, Pr, Sm and Nd A total of at least one metal selected from the group consisting of more than 0 atomic% and not more than 1.8 atomic%, with the balance being Mg, and a and b are molten metals satisfying the following formulas (1) to (3). A step of rapidly solidifying at a cooling rate of 5 × 10 ⁴ seconds or more to produce a rapidly solidified product.

(1) 0.2≤a≤3.0

(2) 0.3 ≤ b≤ 1.8

(3)-0.2 a + 0.5 5 ≤ b ≤-0.2 a + 1.95

(4)-0.2 a + 0.5 5 ≤ b ≤-0.2 a + 1.80

The method for producing a high-strength, high-toughness magnesium alloy according to the present invention includes the step of: containing at least one atomic% of Zn, and adding at least one rare earth element selected from the group consisting of La, Ce and Mm to a total of b atoms % contained, and the balance of Mg, a and b are the molten metal satisfy the following formula (1) to (3), it is rapidly solidified at 7 X 1 0 ⁴ K / sec or more cooling rate making rapidly solidified product Step is provided.

(1) 0.2≤a≤3.0

(2) 0.3 ≤ b≤ 1.8 (3) — 0.2 a + 0.55 ≤ b ≤-0.2 a + 1.95 It is more preferable to use the following equation (4) instead of the above equation (3). That is, it is more preferable that the above a and b satisfy the above equations (1) and (2) and the following equation (4).

(4) -0.2 a + 0.55 ≤ b≤- 0.2 a + 1.80

The method for producing a high-strength, high-toughness magnesium alloy according to the present invention includes the step of: containing at least one atomic% of Zn and at least one rare earth element selected from the group consisting of La, Ce and Mm in total. b at%, Si, Gd, Dy, Tb, Ho, Er, Ca, Mn, Ag, Li, Zr, Th, Y, Yb, Eu, Pr, Sm and ぴ Nd A total of at least one metal selected from the group consisting of more than 0 atomic% and 1.8 atomic% or less, with the balance being Mg, and a and b satisfying the following formulas (1) to (3) Is rapidly solidified at a cooling rate of 7 × 10 ⁴ KZ seconds or more to produce a rapidly solidified product.

(1) 0.2≤a≤3.0

(2) 0.3 ≤b≤l. 8

(3)-0.2 a + 0.55 ≤ b≤-0.2 a + 1.95

It is more preferable to use the following formula (4) instead of the above formula (3). In other words, it is more preferable that the a and b satisfy the above-mentioned expressions (1) and (2) and the following expression (4).

(4) -0.2 a + 0.55≤b≤-0.2 a + l.80

In addition, the method for producing a high-strength and high-toughness magnesium alloy according to the present invention may further comprise, after the step of forming the rapidly solidified product, a step of plastically adding the rapidly solidified product to form a plastic processed product. It is possible. By applying plastic working, shearing force is applied to bring about metal bonding between rapidly solidified powders, etc., and a dense plastic processed product is created.

In the method for producing a high-strength and high-toughness magnesium alloy according to the present invention, after the step of forming the rapidly solidified product, a step of preforming the rapidly solidified product to form a preformed product; and Process of forming a plastic workpiece by plastic working It is also possible to provide further.

Further, in the method for producing a high-strength and high-toughness magnesium alloy according to the present invention, after the step of forming the rapidly solidified product, a step of solidifying and shaping the rapidly solidified product by plastic working; It is possible to further provide a step of performing plastic working on the object.

Further, the method for producing a high-strength and high-toughness magnesium alloy according to the present invention may further include, after the step of forming the plastic workpiece, a step of performing secondary plastic working on the plastic workpiece.

In the method for producing a high-strength and high-toughness magnesium alloy according to the present invention, the preforming may be compression molding or canning.

In the method for producing a high-strength, high-toughness magnesium alloy according to the present invention, the plastic working may be at least one of extrusion, rolling, ECAE, and forging. 4. Brief description of drawings

FIG. 1 is a graph showing the results of evaluation of the bite hardness and ductility of each of the magnesium alloys of Examples 1 to 18 and Comparative Examples 1 to 11.

Figure 2 shows the relationship between volume fraction (V f) and Vickers hardness (Hv) when annealing was performed at 573K in Examples 2, 3, 5, 6, 8, and 9 and Comparative Examples 2 to 7. It is a graph.

Figure 3 shows the relationship between volume fraction (vf) and Vickers hardness (Hv) when annealing was performed at 673 ° in Examples 2, 3, 5, 6, 8, and 9 and Comparative Examples 2 to 7. It is a graph.

FIG. 4 is a diagram in which the hardness lines are drawn on the graph of FIG.

FIG. 5 is a graph showing the relationship between the cooling rate during rapid cooling, Vickers hardness, and ductility.

FIG. 6A is a photograph showing the crystal structure of the test piece denoted by reference numeral 1 shown in FIG. 5, and FIG. 6B is a photograph showing the crystal structure of the test piece denoted by reference numeral 2 shown in FIG. FIG. 7 is a photograph showing the crystal structure of the test piece denoted by reference numeral 3 shown in FIG. FIG. 8 is a view showing a photograph of a crystal structure after preparing a test piece from a molten metal containing 2.0 atomic% of La by a liquid quenching method and annealing this test piece at 573K.

FIG. 9 is a view showing a photograph of a crystal structure after preparing a test piece from a molten metal containing 1.5 atomic% of La by a liquid quenching method and annealing the test piece at 573K.

FIG. 10 is a graph showing the results of the Pickers hardness and ductility evaluation of each of the magnesium alloys of Examples 19 to 24 and Comparative Examples 12 to 19.

FIG. 11 is a graph showing the results of evaluation of the Vickers hardness and ductility of each of the magnesium alloys of Examples 25 to 28 and Comparative Examples 20 to 24.

5 BEST MODE FOR CARRYING OUT THE INVENTION

Returning to the basics, the present inventors have studied the strength and toughness of the alloy starting from a binary magnesium alloy, and have further extended the study to a multi-element magnesium alloy. As a result, a magnesium alloy having both high strength and toughness is a magnesium alloy having a rare earth element of La, Ce, or Mm, which is a Mg—Zn—RE (rare earth element) alloy described below. Furthermore, unlike the prior art, a low zinc content of 3.0 atomic% or less and a rare earth element content of 1.8 atomic% or less provide unprecedented high strength and high toughness. This has led to the present invention.

(Embodiment 1)

The magnesium alloy according to Embodiment 1 of the present invention is basically a ternary or quaternary alloy composed of Mg, Zn, and a rare earth element, and the rare earth element is composed of Ce, La, and Mm. One or more elements selected from the group. Here, M m (mish metal) is a mixture or alloy of a plurality of rare earth elements mainly composed of Ce and La, and is used to precisely remove useful rare earth elements such as Sm and Nd from ore. After refining, the composition of which depends on the composition of the ore before refining Things.

Assuming that the content of zinc is a atomic% and the content of the rare earth element is b atomic%, it is preferable to satisfy the following expressions (1) to (3).

(1) 0.2≤a≤3.0

(2) 0.3 ≤b≤ l. 8

(3)-0.2 a + 0.5 5 ≤ b ≤-0.2 a + 1.95

(4)-0.2 a + 0.5 5 ≤ b ≤-0.2 a + 1.80

Next, a method for producing the magnesium alloy of the present invention will be described.

First, the above-mentioned magnesium alloy by hot melt to prepare a molten alloy, the solvent water 3. 5 X 1 0 ⁴ K / sec or more cooling rate, and more preferably from 7 X 1 0 ⁴ or KZ seconds cooling rate The powder, flakes, ribbons or thin wires obtained are preformed and solidified. The preforming may be through a billet forming step by compressing a powder, a flake, a ribbon or a thin wire, or may be a caning or the like. The preforming is for facilitating plastic working, and has effects such as solidifying powder or the like to prevent oxidation during plastic working and facilitating handling.

In addition, the plastic working may be performed by extrusion. For example, it is preferable to perform the extrusion under the conditions of an extrusion temperature of 250 to 500 ° C., an extrusion pressure of 200 to: L 000 MPa, and an extrusion ratio of 5 to 100. Les ,. Rapid solidification includes gun method, piston-anvil method, centrifugal method, single-roll method, twin-roll method, or spray method, high-pressure gas atomization method, spinning in rotating liquid, and injection molding of molten metal. The roll method, twin roll method or high pressure gas atomization method is particularly suitable.

The magnesium alloy produced in this way has a normal hcp structure and does not have a long-period hexagonal structure. The cells or crystal grains of the magnesium alloy are rod-shaped, and the width of the cells or crystal grains is 500 nm or less. There is a segregation layer having a thickness of 100 nm or less at a cell boundary or a grain boundary in a molded product obtained by the solidification molding, and a particle size of several tens nm or less in a cell or a crystal grain in the molded product. For example, fine spherical compounds of 50 nm or less are deposited almost uniformly. The crystal structure of the molded product is a structure mainly composed of a lath structure having the spherical compound. By suppressing the segregation layer at the cell boundaries or grain boundaries to 100 nm or less and uniformly depositing compounds, for example, spherical compounds, in the cells or crystal grains, a high-strength and high-toughness magnesium alloy can be obtained. It is thought that it is possible.

The magnesium alloy obtained as described above has high strength and high toughness.Even if there is a magnesium alloy in which the performance of strength and toughness alone is superior to that of the magnesium alloy of the present invention, in both performance of strength and toughness No magnesium alloy has ever surpassed the magnesium alloy of the present invention. Particularly, magnesium alloys of recent years require both high strength and high toughness, but the magnesium alloy of the present invention exactly meets these requirements.

Further, in the Mg—Zn_RE-based magnesium alloy of the present invention, both magnesium and zinc are inexpensive metals, and La and Ce are also inexpensive metals of low utility value among rare earth elements. Misch metal can also be obtained as an inexpensive alloy after removing expensive rare earth elements other than La and Ce. Therefore, the Mg—Zn—RE-based magnesium alloy of the present invention can be produced with an inexpensive material despite having high performance, which is extremely advantageous.

Further, in the Mg—Zn_RE based magnesium alloy of the present invention, since the content of zinc and the rare earth element is low, characteristics of Mg having a small specific gravity can be sufficiently obtained.

(Embodiment 2)

In the magnesium alloy according to Embodiment 2 of the present invention, the components other than zinc and the rare earth element having the contents in the above-described range are magnesium, but contain other elements to such an extent that alloy characteristics are not affected. Is also good.

That is, the magnesium alloy of the present invention has an M g—Z n— — Z n— RE—Me system (Me is Si, Gd, Dy ゝ Tb, Ho, Er, Ca, Mn, Ag, Li, Zr, Th, Y, Yb, Eu, Pr, 3111 And 1 ^ (at least one element selected from the group consisting of 1.) The content of Me is more than 0 atomic% and 1.8 atomic ° / ₀ or less. Other properties can be improved while maintaining strength and toughness.

The method of manufacturing a magnesium alloy according to the present embodiment is the same as the method of manufacturing the first embodiment.

(Embodiment 3)

A method for manufacturing a magnesium alloy according to Embodiment 3 of the present invention will be described.

A magnesium alloy having the composition of Embodiment 1 or 2 is rapidly solidified by the same manufacturing method as in Embodiment 1 and solidified to obtain a molded product. Next, a first plastic working is performed on the molded product to produce a first plastic processed product (primary workpiece). The first type of plastic working refers to processing such as extrusion, rolling, ECAE, and forging.

Thereafter, a second plastic working is performed on the first plastic processed product to produce a second plastic processed product (secondary processed product). The second type of plastic working means processing such as extrusion, rolling, ECAE, forging, drawing, and bending. Products and components such as PC housings are manufactured by the second plastic working. In the present embodiment, the first plastic working is performed, and then the second plastic working is performed to manufacture a product or a part. It is also possible to manufacture products and parts.

In the quenched and solidified product that has been quenched and solidified, in the molded product that has been solidified and formed, and in the first and second plastically processed products, Mg-Zn-rare earth element-based intermetallic compounds such as spherical compounds are precipitated. These are high strength and high toughness magnesium alloys.

According to the first to third embodiments, it is useful as an alloy for high-tech equipment requiring high performance in both strength and toughness, and La, Ce, and Mm are rare earth elements. Inexpensive among the class elements, and also advantageous in terms of cost

(Example)

Hereinafter, examples of the magnesium alloy according to the present invention will be described, but the examples do not limit the present invention.

[Examples 1 to 18 and Comparative Examples 1 to 11]

Examples 1 to 18 and Comparative Examples 1 to 11 relate to a Mg—Zn—La ′ ternary alloy.

Mg, Zn, and La were weighed so as to have the alloy compositions shown in Table 1, filled into a ruppo, and subjected to high frequency melting in an Ar gas atmosphere to prepare a total of 29 kinds of molten alloys.

Since the bulk body made of this magnesium alloy is not suitable as a sample for measuring strength and ductility, the following samples were separately prepared. From the above 29 kinds of molten alloys, a single roll type liquid quenching method was used to form two ribbons for each composition, a total of 58 pieces, a ribbon shape of about 1000 mm in length, 2 mm in width and 20 to 40 μm in thickness. Test pieces were prepared. Cooling rate during liquid quenching was a 1 X 1 0 ⁵ KZ seconds.

As mentioned above, extrusion is performed at an extrusion temperature of 250 to 500 ° C and usually at 300 to 400 ° C, so one of the test pieces of each composition is at 300 ° C (573 K) and the other is at 400 ° C. Heat treatment at ° C (673 K) approximated that of a magnesium alloy obtained by normal extrusion forming.

A force is applied to the thus obtained rifon-shaped test piece so that it bends substantially at the center in the longitudinal direction, and it is checked whether each ribbon-shaped test piece is ductile, brittle or semi-ductile. Was. 1 Ripon-shaped test piece that does not break when bent back at 80 ° has ductility, and Ripon-shaped test piece that breaks when bent back at 180 ° has semi-ductility and breaks before reaching 180 ° The piece was evaluated as brittle. The results of the Vickers hardness (Hv) and ductility evaluation of each of the magnesium alloys of Examples 1 to 18 and Comparative Examples 1 to 11 are summarized in Table 1 and the graph of FIG. In Table 1, ◎ indicates ductility, X indicates brittleness, and 〇 indicates semi-ductility. In the graph, 〇 indicates ductility, Indicates brittleness, and a semi-circle indicates semi-ductility.

[table 1]

Composition (atomic%) anneal intermetallic compound hardness toughness

Mg Z n L a Temperature (K) V f (%) (Hv)

573 3.6 119 Example 1 98.0 1.5 0.5 ◎

673 3.6 90 ◎

573 8.7 133 Example 2 97.5 1.5 1.0 ◎

673 8.7 107 ◎

573 13.7 151 〇 Example 3 97.0 1.5 1.5

673 13.7 121 〇

573 3.6 113 Example 4 98.5 1.0 0.5 ◎

673 3.6 89 ◎

573 8.7 134 Example 5 98.0 1.0 1.0 ◎

673 8.7 115 ◎

573 13.7 163 〇 Example 6 97.5 1.0 1.5

673 13.7 123 ◎

573 3.6 107 Example 7 99.0 0.5 0.5 ◎

673 3.6 81 ◎

573 8.7 121 Example 8 98.5 0.5 1.0 ◎

673 8.7 96 ◎

573 13.7 158 Example 9 98.0 0.5 1.5 ◎

673 13.7 130 ◎

573 15.7 165 X Example 10 97.3 1.0 1.7

673, 15.7 118 〇

97.7 573 16.2 163 X Example 11 0.5 1.75

5 673 16.2 123 〇

573 6.2 129 Example 12 98.5 0.75 0.75 ◎

673 6.2 95

98.2 573 8.7 130 Example 13 0.75 1.0 ◎

5 673 8.7 101 ◎

573 11.2 141 Example 14 98.0 0.75 1.25 ◎

673 11.2 111 ◎

97.7 573 13.7 160 〇 Example 15 0.75 1.5

5 673 13.7 123 ◎

573 16.2 166 X Example 16 97.5 0.75 1.75

673 16.2 125 〇

98.2 573 6.2 139 Example 17 1.0 0.75 ◎

5 673 6.2 100 ◎ Example 18 99.0 2.0 0.5 573 3.6 126 ◎ 673 3.6 90 ◎

573 3.6 92

Comparative Example 1 99.0 0 0.5 ◎

673 3.6 61 ◎

573 8.7 100

Comparative Example 2 99.0 0 1.0 ◎

673 8.7 83 ◎

573 13.7 127 X Comparative 3 98.5 0 1.5

673 13.7 107 X

573 18.7 147 X Comparative 4 98.0 0 2.0

673 18.7 110 X

573 18.7 183 X Comparative 5 96.5 1.5 2.0

673 18.7 137 X

573 18.7 168 X Comparative 6 97.0 1.0 2.0

673 18.7 112 X

573 18.7 162 X Comparative 7 97.5 0.5 2.0

673 18.7 122 X

573 0 78

Comparative Example 8 98.5 0.5 0 ◎

673 0 1 ―

573 0 85

Comparative Example 9 99.0 1.0 0 ◎

673 0 one

573 0 102

Comparative Example 10 99.0 2.0 0 ◎

673 0 ―

573 0 102

Comparative Example 11 96.0 4.0 0

In the magnesium alloys of Examples 1 to 18 described above, an Mg—Zn_La intermetallic compound (for example, a spherical compound) was precipitated in the cell or the crystal grain. The volume fraction of the intermetallic compound of the magnesium alloy to which 2. atomic% of lanthanum is added is 18.7%, and the volume fraction of 1.3.7% and 1.0 atomic% when 1.5 atomic% is added. With the addition, the volume fraction was estimated to be 8.7%.

The relationship between the volume fraction (V f) and Vickers hardness (Hv) when annealing was performed at 573 K or 670 K was calculated using the zinc addition amount (0 atomic%, 0.5 atomic%, (1.0 atomic% and 1.5 atomic%) are shown in the graphs of Fig. 2 and Fig. 3, respectively.

From Table 1 and Figures 1 to 3, the hardness of the Mg-Ζη-La La ternary alloy increases as the lanthanum addition increases, but the lanthanum addition reaches 2 atomic%. Then, it was found that the alloy became brittle. Zero zinc addition , The amount of lanthanum added is 1.5 atoms. / ₀ also made the obtained magnesium alloy brittle.

In addition, comparing the graphs of FIG. 2 and FIG. 3, it was found that the lower the annealing temperature, the higher the hardness of the obtained alloy as a whole, and the higher the annealing temperature, the better the ductility.

According to Table 1 and FIG. 1, Zn is contained in an amount of 0.2 to 3.0 atomic%, La is contained in an amount of 0.3 to 1.8 atomic%, and the balance is M It can be seen that high strength and high toughness were obtained for the ribbon-shaped test piece composed of g. Further, as described above, the test piece approximates a magnesium alloy obtained by ordinary extrusion molding. Therefore, the ductility, brittleness, and semi-ductility properties of each specimen correspond to those of magnesium alloy obtained by ordinary extrusion. The Vickers hardness obtained from the test specimen corresponds to the strength of the magnesium alloy obtained by ordinary extrusion, and when the value of the Vickers hardness is quadrupled, it becomes an approximate value of the yield strength MPa. . For example, if the Vickers hardness is 100 or more, the yield strength of a magnesium alloy obtained by ordinary extrusion molding is considered to be 40 OMPa or more.

FIG. 4 is a diagram in which the hardness lines are drawn on the graph of FIG. Vickers hardness

The iso-hardness line of 150 is indicated by reference numeral 150 and the iso-hardness line of Vickers hardness 140 is indicated by reference numeral 140 and the iso-hardness line of Vickers hardness 130 is indicated by reference numeral. It is indicated by the reference numeral 130 and the contour line of the Vickers hardness of 120 is indicated by the reference numeral 120.The reference line is indicated by the contour line of the Vickers hardness of 110.

This is indicated by 110. The inside of each isohardness line is a composition range showing each Vickers hardness. According to FIG. 4, it can be seen that the results with the best characteristics were obtained in a magnesium alloy having a Zn content of 0.5 at% and a La content of 1.5 at% and the balance being Mg.

FIG. 5 is a graph showing the relationship between the cooling rate during rapid cooling, Vickers hardness, and ductility. As shown in FIG. 5, a Z n contains 0.5 atomic%, the L a 1. 5 atoms ^_0/0 contains, from the molten metal and the balance of M g, by a single roll liquid quenching method, the length Ripon-shaped test pieces of about 100 O mm, width 2 mm, and thickness of 20 to 40 μm were prepared. At this time, the cooling rate during rapid cooling of the liquid was changed, and test specimens were prepared at each cooling rate.

Next, Vickers hardness was measured without annealing the obtained test piece (as quenched;). After annealing the obtained test piece at 573 K, Vickers hardness was measured (annealed at 573 K). Further, the obtained test piece was annealed at 673 K, and then the Vickers hardness was measured (annealed at 673 K). ₀ According to FIG. 5, it was quenched at a cooling rate of 3.5 × 10 ⁴ s or more. Regarding the test pieces, high strength and high toughness were obtained for both the annealed and non-annealed test pieces. In addition, with respect to the test pieces quenched at a cooling rate of 7 × 10 ⁴ Κ / sec or more, both the annealed test pieces and the non-annealed test pieces have high strength and high toughness.

6A is a photograph showing the crystal structure of the test piece denoted by reference numeral 1 shown in FIG. 5, and FIG. 6B is a photograph showing the crystal structure of the test piece denoted by reference numeral 2 shown in FIG. FIG. 7 is a photograph showing the crystal structure of the test piece denoted by reference numeral 3 shown in FIG. The test specimens with reference numerals 1 to 3 were annealed at 573 K.

In the photograph of the crystal structure shown in Fig. 6A, the structure of the alloy is mainly composed of a lath-like structure having a fine spherical compound with a particle diameter of 50 nm or less, and the width of the cell or crystal grain ( The short diameter of the rod-shaped portion is less than 300 nm. There is a segregation layer with a thickness of 100 nm or less at the cell boundary or the grain boundary. It is considered that high strength is obtained by having the above lath structure. Furthermore, since the segregation layer at the cell boundary or grain boundary is as thin as 1 O Onm or less, high toughness (high ductility) can be obtained without embrittlement.

In the photograph of the crystal structure shown in Fig. 6B, the cells or crystal grains are not finer than in Fig. 6A, and the thickness of the segregation layer, which is deviated at the cell boundaries or grain boundaries, is larger than in Fig. 6A. ing.

In the photograph of the crystal structure shown in Fig. 7, the cells or crystal grains are not much finer than in Fig. 6B, and the thickness of the segregation layer deviated at the cell boundaries or grain boundaries is also smaller than that in Fig. 6B. It is even thicker.

According to FIGS. 6A, 6B and 7, high strength and high strength can be obtained when the fine spherical compound in the cell or crystal grain has a particle size of 50 nm or less and precipitates almost uniformly. It can be seen that toughness characteristics can be obtained. It is considered that high toughness characteristics can be obtained when the thickness of the segregation layer at the cell boundary or crystal grain boundary is as thin as 100 nm or less. Also, it is considered that high strength and high toughness characteristics can be obtained in the case of a fine structure with a cell or crystal grain width of 300 nm or less (500 nm or less is acceptable).

8, sigma 11 contains 0.5 atomic%, the L a 2. contains 0 atomic%, the molten metal and the balance of Mg, 1 X 1 0 ⁵ KZ single roll liquid quenching cooling rate in seconds Figure shows a photograph of the crystal structure after preparing a lipon-shaped test piece with a length of about 100 Omm, a width of 2 mm, and a thickness of 20 to 40 / m by the method, and annealing this test piece at 573 K. It is.

Figure 9 contains a 211 0.5 atomic%, 1 ^ & 1. containing 5 atomic%, the molten metal and the balance of Mg, 1 X 1 0 ⁵ K / sec single-roll liquid cooling rate of This figure shows a photograph of the crystal structure of a ribbon-shaped test piece with a length of about 1000 mm, a width of 2 mm, and a thickness of 20 to 40 prepared by the quenching method and annealing this test piece at 573 K. .

When the La content was 1.5 atomic%, a crystal structure having high strength and high toughness characteristics was obtained. On the other hand, when the La content was 2.0 atomic%, high strength and high toughness were obtained. It was confirmed that a crystal structure having the following characteristics could not be obtained. The reason for such a result will be described below.

In the crystal structure shown in FIG. 9, a structure similar to the crystal structure shown in FIG. 6A is obtained, and it is considered that high strength and high toughness characteristics are obtained.

That is, it is considered that high strength and high toughness characteristics can be obtained when the fine spherical compound in the cell or crystal grain has a particle diameter of 50 nm or less and is almost uniformly precipitated. It is considered that high toughness characteristics can be obtained when the thickness of the segregation layer at the cell boundary or grain boundary is as thin as 100 nm or less. In addition, cells or It is thought that high strength and high toughness characteristics can be obtained in a fine structure with a crystal grain width of 300 nm or less (or 500 nm or less).

On the other hand, in the crystal structure shown in FIG. 8, the cell structure is large, cells or crystal grains are not finely formed, and a thick segregation layer at the cell boundaries or crystal grain boundaries is devoted. It is considered that the alloy properties become brittle due to such a thick segregation layer.

Observation of an alloy structure having a La content of 0.5 atomic% revealed that no lath structure was formed. Therefore, it is probable that high strength was not obtained with this alloy.

It has been confirmed that the segregation layer contains Mg, Zn, and a rare earth element (La).

[Examples 19 to 24 and Comparative Examples 12 to: L 9]

Examples 19 to 24 and Comparative Examples 12 to 19 relate to a Mg—Zn—Ce ternary alloy.

Mg, Zn, and Ce were weighed so as to have the alloy compositions shown in Table 2, filled in a crucible, and subjected to high frequency melting in an Ar gas atmosphere to prepare a total of 14 kinds of molten alloys.

Under the same conditions as in Example 1, a total of 14 hardness test samples and lipon-shaped test pieces were prepared from these molten alloys, and the Vickers hardness (Hv) of the former and the ductility of the latter were evaluated.

Table 2 and FIG. 10 summarize the results of evaluation of Vickers hardness (Hv) and ductility of each of the magnesium alloys of Examples 19 to 24 and Comparative Examples 12 to 19.

Table 2 and Fig. 10 show that the hardness of the Mg-Zn-Ce ternary alloy increases as the amount of added cerium increases, but when the amount of added cerium reaches 1.5 atomic%. It was found that the alloy became semi-ductile and became brittle when it reached 2.0 at%.

[Table 2] Hardness and toughness of Mg-ZnCe alloy

[Examples 25 to 28 and Comparative Examples 20 to 24]

Examples 25 to 28 and Comparative Examples 20 to 24 relate to an Mg—Zn—Mm alloy, and Mm used was Ce rich.

Mg, Zn, and Mm were weighed so as to have the alloy compositions shown in Table 3, filled in a ruppo, and subjected to high frequency melting in an Ar gas atmosphere to prepare a total of nine types of molten alloys. Under the same conditions as in Example 1, a total of 9 hardness tests were performed from these molten alloys. We prepared a sample for use and a ripon-shaped test piece, and evaluated the Vickers hardness (Hv) of the former and the ductility of the latter.

Table 3 and FIG. 11 summarize the results of Vickers hardness (Hv) and ductility evaluation of each of the magnesium alloys of Examples 25 to 28 and Comparative Examples 20 to 24.

From Table 3 and Fig. 11, it can be seen that the hardness of the obtained alloy increases with the addition of Mm in the Mg-Zn-Mm alloy, but when the addition of!! When the amount of Mm reaches 1.5 atomic%, the alloy becomes semi-ductile, and when it reaches 2.0 atomic%, it becomes brittle, but when the content is lower than this, it shows good properties. I understood. 3]

Hardness and toughness of Mg-Zn-Mm alloy

It should be noted that the present invention is not limited to the above-described embodiments and examples, and various modifications can be made without departing from the gist of the present invention.

Claims

The scope of the claims

1. It contains & atomic% of Zn, and contains b atomic% in total of at least one rare earth element selected from the group consisting of La, Ce and Mm, and the balance consists of Mg, and a and b Is a high-strength, high-toughness magnesium alloy satisfying the following equations (1) to (3).

(1) 0.2 ≤ a ≤ 3.0

(2) 0.3 ≤ b≤ 1.8

(3)-0.2 a + 0.55 ≤ b≤-0.2 a + 1.95

2. It contains a atomic% of Zn and contains b atomic% in total of at least one rare earth element selected from the group consisting of La, Ce and Mm, and the balance consists of Mg, and a and b Is a high-strength, high-toughness magnesium alloy satisfying the following equations (1) to (3).

(1) 0.2≤a≤3.0

(2) 0.3 ≤ b≤ 1.8

(3)-0.2 a + 0.55 ≤ b ≤ 0.2 a + 1.80

3. Zn is a atom. /. At least one rare earth element selected from the group consisting of La, Ce and Mm in a total of 1) atomic%, Si, Gd, Dy,

Total of at least one metal selected from the group consisting of Tb, Ho, Er, Ca, Mn, Ag, Li, Zr, Th, Y, Yb, Eu, Pr, Sm and Nd A high-strength, high-toughness magnesium alloy that contains more than 0 at.

(1) 0.2≤a≤3.0

(2) 0.3 ≤ b≤ 1.8

(3)-0.2 a + 0.55 ≤ b≤-0.2 a + 1.95

4. Containing _& 11 _& atomic%, at least 1) atomic% of at least one rare earth element selected from the group consisting of La, Ce and Mm, Si, Gd, Dy, Tb, Ho, Er, Ca, Mn, Ag, Li, Zr, Th, Y, Yb, Eu,

Contains at least one metal selected from the group consisting of Pr, Sm, and Nd in total of more than 0 atomic% and 1.8 atomic% or less, with the balance being Mg, and a and b are represented by the following formula (1) High strength and high toughness magnesium alloy that satisfies (3). (1) 0.2≤a≤3.0

(2) 0.3 ≤ b≤ 1.8

(3)-0.2 a + 0.5 5 ≤ b ≤-0.2 a + 1.80

5. It contains a atomic% of Zn and at least one rare earth element selected from the group consisting of La, Ce and Mm in a total of 1) atomic%, and the balance consists of Mg; b is a quenched solidified product after quenching and solidifying a molten metal satisfying the following equations (1) to (3)

The rapidly solidified product is a high-strength, high-toughness magnesium alloy having a lath-like structure having a fine spherical compound having a particle size of 50 nm or less.

(1) 0.2≤a≤3.0

(2) 0.3 ≤ b≤ 1.8

(3) — 0.2 a + 0.5 5 ≤ b ≤-0.2 a + 1.95

6. Zn is a atom. / ₀ content, at least one rare earth element selected from the group consisting of La, Ce and Mm is contained in a total of b atom%, and the balance is made of Mg, and a and b are represented by the following formulas (1) to (3) is a rapidly solidified product after rapidly solidifying a molten metal satisfying

(1) 0.2≤a≤3.0

(2) 0.3 ≤b≤ l. 8

(3)-0.2 a + 0.5 5 ≤ b ≤-0.2 a + 1.80

7. It contains & atomic% of Zn, and contains b atomic% in total of at least one rare earth element selected from the group consisting of La, Ce and Mm, and Si, Gd, Dy,

At least one metal selected from the group consisting of Tb, Ho, Er, Ca, Mn, Ag, Li, Zr, Th, Y, Yb, Eu, Pr, Sm and Nd in total More than 0 atomic% and not more than 1.8 atomic%, the balance being Mg, and a and b are quenched and solidified products after quenching and solidifying a molten metal satisfying the following formulas (1) to (3). The rapidly solidified product has a lath shape with a fine spherical compound with a particle size of 50 nm or less. High strength, high toughness magnesium alloy with a microstructure.

(1) 0.2≤a≤3.0

(2) 0.3 ≤ b≤ 1.8

(3) — 0.2 a + 0.5 5 ≤ b ≤-0.2 a + 1.95

8. It contains _& 11% by atom, contains at least one rare earth element selected from the group consisting of La, Ce and Mm in total atom%, Si, Gd, Dy, Tb, Ho , Er, Ca, Mn, Ag, Li, Zr, Th, Y, Yb, Eu, Pr, Sm, and Nd, in a total of 0 atoms. % More than 1.8 atoms. / ₀ or less, the balance being made of Mg, and a and b are quenched solids after quenching and solidifying a molten metal satisfying the following formulas (1) to (3); A high-strength, high-toughness magnesium alloy with a lath-like structure having a fine spherical compound of 50 nm or less.

(1) 0.2≤a≤3.0

(2) 0.3 ≤ b≤ 1.8

(3) — 0.2 a + 0.5 5 ≤ b ≤-0.2 a + 1.80

9. Contains & at% of Zn, contains at least b at% of at least one rare earth element selected from the group consisting of La, Ce and Mm, with the balance being Mg, a and b Is a rapidly solidified product obtained by quenching and solidifying a molten metal satisfying the following formulas (1) to (3).

The plastic workpiece is a high-strength, high-toughness magnesium alloy having a lath-like structure having a fine spherical compound having a particle size of 50 nm or less.

(1) 0.2≤a≤3.0

(2) 0.3 ≤ b≤ 1.8

(3)-0.2 a + 0.5 5 ≤ b ≤-0.2 a + 1.95

1 0. It contains _& 11% by atom, contains at least one rare earth element selected from the group consisting of La, Ce and Mm in total 1) atom%, and the balance consists of Mg, a And b are quenched and solidified molten metal satisfying the following formulas (1) to (3) to form a quenched solidified product, and the quenched solidified product is subjected to plastic working, The plastic workpiece is a high-strength, high-toughness magnesium alloy having a lath-like structure having a fine spherical compound having a particle size of 50 nm or less.

(1) 0.2≤a≤3.0

(2) 0.3 ≤ b≤ 1.8

(3) — 0.2 a + 0.55≤ b≤- 0.2 a + 1.80

1 1. Contains & 11% of ∑11 and contains at least one rare earth element selected from the group consisting of La, Ce and Mm in total. / _0, contains S, Gd, Dy, Tb, Ho, Er, Ca, Mn, Ag, Li, Zr, Th, Y, Yb, Eu, Pr, Sm and Nd A total of at least one metal selected from the group consisting of more than 0 atomic% and not more than 1.8 atomic%, with the balance being Mg, and a and b satisfying the following formulas (1) to (3) To form a rapidly solidified product by subjecting the rapidly solidified product to plastic working,

(1) 0.2≤a≤3.0

(2) 0.3 ≤ b≤ 1.8

(3)-0.2 a + 0.55 ≤ b≤-0.2 a + 1.95

1 2. It contains & atomic% of Zn, contains 13 atomic% in total of at least one rare earth element selected from the group consisting of La, Ce and Mm, and contains Si, Gd, Dy, Tb, At least one metal selected from the group consisting of Ho, Er, Ca, Mn, Ag, Li, Zr, Th, Y, Yb, Eu, Pr, Sm and Nd is 0 atomic% in total. Super 1.8 atomic% or less, the balance is made of Mg, and a and b are rapidly solidified by rapidly solidifying molten metal that satisfies the following formulas (1) to (3) to produce a rapidly solidified solid, It is a plastic product after performing the process,

The plastically processed product is a high-strength, high-toughness magnesium alloy having a lath-like structure having a fine spherical compound having a particle size of 50 nm or less.

(1) 0.2≤a≤3.0

(2) 0.3 ≤ b≤ 1.8 (3)-0.2 a + 0.55 ≤ b ≤ 0.2 a + 1.80

1 3. Contains 211% by atom and 211%, at least one rare earth element selected from the group consisting of La, Ce and Mm contains a total of b atom%, and the balance consists of Mg. b is an extrudate obtained by extruding the molten solid satisfying the following formulas (1) to (3) by rapidly solidifying the molten metal to form a rapidly solidified product, and extruding the rapidly solidified product. A high-strength, high-toughness magnesium alloy with a lath-like structure having fine spherical compounds of nm or less.

(1) 0.2≤a≤3.0

(2) 0.3 ≤ b≤ 1.8

(3) One 0.2 a + 0.55 ≤ b ≤-0.2 a + 1.95

14. It contains & atomic% of 211, contains at least one rare earth element selected from the group consisting of La, Ce and Mm in total of 13 atomic%, and the balance consists of Mg, and a and b are A molten solid satisfying the following formulas (1) to (3) is quenched and solidified to form a quenched solidified product, and is an extruded product obtained by extruding the quenched solidified material, wherein the extruded product has a particle size of 50 nm or less. A high-strength, high-toughness magnesium alloy having a lath-like structure with fine spherical compounds.

(1) 0.2≤a≤3.0

(2) 0.3 ≤ b≤ 1.8

(3)-0.2 a + 0.55 ≤ b ≤ 0.2 a + 1.80

15.2 & atomic%, at least b at% of at least one rare earth element selected from the group consisting of La, Ce and Mm, Si, Gd, Dy, Tb, At least one metal selected from the group consisting of Ho, Er, Ca, Mn, Ag, Li, Zr, Th, Y, Yb, Eu, Pr, Sm, and Nd in total of 0 More than at.% And below 1.8 at.%, The balance being Mg, and a and b are rapidly solidified by quenching and solidifying a molten metal satisfying the following formulas (1) to (3) to produce a rapidly solidified product. Extruded after extrusion to

The extruded product is a high-strength and high-toughness magnesium alloy having a lath-like structure having a fine spherical compound having a particle size of 50 nm or less. (1) 0.2≤a≤3.0

(2) 0.3 ≤ b≤ 1.8

(3)-0.2 a + 0.55 ≤ b ≤ 0.2 a + 1.95

1 6. It contains Zn at a atomic%, and contains at least one rare earth element selected from the group consisting of La, Ce and Mm in a total of b atomic%, Si, Gd, Dy,

'' Total of at least one metal selected from the group consisting of Tb, Ho, Er, Ca, Mn, Ag, Li, Zr, Th, Y, Yb, Eu, Pr, Sm, and Nd The content is more than 0 at.% And not more than 1.8 at.%, The balance is made of Mg, and a and b are rapidly solidified by quenching and solidifying a molten metal satisfying the following formulas (1) to (3). An extruded product after extruding the cold coagulated product,

The extruded product is a high-strength high-toughness magnesium alloy having a lath-like structure having a fine spherical compound having a particle size of 50 nm or less.

(1) 0.2≤a≤3.0

(2) 0.3 ≤ b≤ 1.8

5 (3) -0.2 a + 0.55≤ b≤- 0.2 a + 1.80

1 7. It contains ∑11% by atomic%, contains at least one rare earth element selected from the group consisting of La, Ce and Mm in a total of ゎ atomic%, with the balance being Mg, b is a rapidly solidified product obtained by rapidly solidifying a molten metal satisfying the following formulas (1) to (3), and is a rolled product after rolling to the rapidly solidified product;

0 The rolled product is a high-strength, high-toughness magnesium alloy having a lath-like structure having a fine spherical compound having a particle size of 50 nm or less.

(1) 0.2≤a≤3.0

(2) 0.3 ≤ b≤ 1.8

(3)-0.2 a + 0.55 ≤ b ≤ 0.2 a + 1.95

25 1 8. It contains a atomic% of Zn, at least one rare earth element selected from the group consisting of La, Ce and Mm in a total of 1> atomic%, with the balance being Mg A and b are quenched and solidified from a molten metal satisfying the following formulas (1) to (3) to form a quenched solidified material, and the rolled material after rolling to the quenched solidified material; The rolled product is a high-strength, high-toughness magnesium alloy having a lath-like structure having a fine spherical compound having a particle size of 50 nm or less.

(1) 0.2≤a≤3.0

(2) 0.3 ≤ b≤ 1.8

(3)-0.2 a + 0.55 ≤ b ≤ 0.2 a + 1.80

1 9. Atomic% of Zn, at least one rare earth element selected from the group consisting of La, Ce and Mm at a total of 1) atomic%, Si, Gd, Dy, Tb , Ho, Er, Ca, Mn, Ag, Li, Zr, Th, Y, Yb, Eu, Pr, Sm, and Nd. More than at.% And below 1.8 at.%, The balance being Mg, and a and b are rapidly solidified by quenching and solidifying a molten metal satisfying the following formulas (1) to (3) to produce a rapidly solidified product. Rolled after rolling to

The rolled product is a high-strength, high-toughness magnesium alloy having a lath-like structure having a fine spherical compound having a particle size of 50 nm or less.

(1) 0.2 ≤ a ≤ 3.0

(2) 0.3 ≤ b≤ 1.8

(3)-0.2 a + 0.55 ≤ b≤-0.2 a + 1.95

20. Contains 211% by atom and at least one rare earth element selected from the group consisting of La, Ce and Mm in a total of 1) atomic%, and contains Si, Gd, Dy, At least one metal selected from the group consisting of Tb, Ho, Er, Ca, Mn, Ag, Li, Zr, Th, Y, Yb, Eu, Pr, Sm and Nd in total Exceeds 0 atomic% and contains 1.8 atomic% or less, with the balance being Mg, and a and b are quenched and solidified by quenching and solidifying a molten metal satisfying the following formulas (1) to (3). Rolled product after rolling into

(1) 0.2≤a≤3.0

(2) 0.3 ≤ b≤ 1.8 (3)-0.2 a + 0.55 ≤ b ≤ 0.2 a + 1.80

21. Contains & at% of Zn, b at% in total of at least one rare earth element selected from the group consisting of La, Ce and Mm, with the balance being Mg, b is a rapidly solidified product obtained by rapidly cooling and solidifying a molten metal satisfying the following formulas (1) to (3), and an E CAE product obtained by performing E CAE on the rapidly solidified product, wherein the EC AE product is: A high-strength, high-toughness magnesium alloy with a lath-like structure having a fine spherical compound with a particle size of 50 nm or less.

(1) 0.2≤a≤3.0

(2) 0.3 ≤b≤ l. 8

(3) -0.2 a + 0.55≤b≤'-0.2 a + l. 95

22. Contains & at% of Zn, b at% in total of at least one rare earth element selected from the group consisting of La, Ce and Mm, with the balance being Mg, b is a rapidly solidified product obtained by quenching and solidifying a molten metal satisfying the following formulas (1) to (3), and the quenched solidified product is subjected to ECAE, and the ECAE product has a particle size of 50 A high-strength, high-toughness magnesium alloy with a lath-like structure having fine spherical compounds of nm or less.

(1) 0.2≤a≤3.0

(2) 0.3 ≤ b≤ 1.8

(3)-0.2 a + 0.55 ≤ b ≤ 0.2 a + 1.80

23. Contains ∑11 at% by atom, contains at least one at least one rare earth element selected from the group consisting of La, Ce, and Mm in b atom%, and contains Si, Gd, Dy, Tb, and Ho. , Er, Ca, Mn, Ag, Li, Zr, Th, Y, Yb, Eu, Pr, Sm and Nd in a total of 0 atomic%. Super 1.8 atomic% or less, the balance being Mg, a and b are quenched and solidified from the molten metal satisfying the following formulas (1) to (3) to produce quenched solidified material. E CAE after CAE,

The ECAE is a high-strength, high-toughness magnesium alloy having a lath-like structure having a fine spherical compound having a particle size of 50 nm or less. (1) 0.2≤a≤3.0

(2) 0.3 ≤ b≤ 1.8

(3) — 0.2 a + 0.55≤ b≤- 0.2 a + 1.95

24. It contains a atomic% of Zn, and contains a total of b atomic% of at least one rare earth element selected from the group consisting of La, Ce and Mm, Si, Gd, Dy, Tb, Ho , Er, Ca, Mn, Ag, Li, Zr, Th, Y, Yb, Eu, Pr, Sm, and Nd, in a total of 0 atoms. % At most 1.8 atomic%, with the balance being Mg, and a and b are rapidly solidified by quenching and solidifying a molten metal that satisfies the following formulas (1) to (3). E CAE after E CAE,

The ECAE is a high-strength, high-toughness magnesium alloy having a lath-like structure having a fine spherical compound having a particle diameter of 50 nm or less.

(1) 0.2≤a≤3.0

(2) 0.3 ≤ b≤ 1.8

(3) — 0.2 a + 0.55≤ b≤- 0.2 a + 1.80

25. It contains & at% of Zn and at least one rare earth element selected from the group consisting of La, Ce and Mm in a total of 1) atm%, and the balance consists of Mg; And b are quenched and solidified from a molten metal satisfying the following formulas (1) to (3) to form a quenched solidified material, and the quenched solidified material is forged after forging.

The forged product is a high-strength, high-toughness magnesium alloy having a lath structure having a fine spherical compound having a particle size of 50 nm or less.

(1) 0.2≤a≤3.0

(2) 0.3 ≤ b≤ 1.8

(3)-0.2 a + 0.55 ≤ b≤-0.2 a + 1.95

26. Contains _{& at} % of Zn, contains b at% in total of at least one rare earth element selected from the group consisting of La, Ce and Mm, the balance consisting of Mg, b is a rapidly solidified product obtained by rapidly solidifying a molten metal satisfying the following formulas (1) to (3), and a forged product obtained by forging the rapidly solidified product. The forged product is a high-strength, high-toughness magnesium alloy having a lath-like structure having a fine spherical compound having a particle size of 50 nm or less.

(1) 0.2≤a≤3.0

(2) 0.3 ≤ b ≤ 1.8

(3) — 0.2 a + 0.55≤ b≤- 0.2 a + 1.80

27. Zn is a atom. / _0, contains at least one rare earth element selected from the group consisting of La, Ce and Mm in a total of 1) atomic%, Si, Gd, Dy, Tb, Ho, Er, 0 atoms in total of at least one metal selected from the group consisting of Ca, Mn, Ag, Li, Zr, Th, Y, Yb, Eu, Pr, Sm and Nd. /. Super 1.8 atoms. / ₀ or less, the balance consisting of Mg, and a and b are quenched and solidified from the molten metal satisfying the following formulas (1) to (3) to produce a quenched solidified material, and after forging the quenched solidified material A forging,

The forged product is a high-strength, high-toughness magnesium alloy having a lath-like structure having a fine spherical compound having a particle size of 50 nm or less.

(1) 0.2 ≤ a ≤ 3.0

(2) 0.3 ≤ b≤ 1.8

(3)-0.2 a + 0.55 ≤ b≤-0.2 a + 1.95

28. Contains a atom% of Zn, and has a total of b atoms of at least one rare earth element selected from the group consisting of La, Ce and Mm. / ₀ contained, consisting of Si, Gd, Dy, Tb, Ho, Er, Ca, Mn, Ag, Li, Zr, Th, Y, Yb, Eu, Pr, Sm and Nd The total content of at least one metal selected from the group is more than 0 atomic% and 1.8 atomic% or less, with the balance being Mg, and a and b quenching the molten metal satisfying the following formulas (1) to (3) Solidifying to form a quenched solid, and forging the quenched solid,

(1) 0.2≤a≤3.0

(2) 0.3 ≤ b≤ 1.8 (3)-0.2 a + 0.5 5 ≤ b ≤-0.2 a + 1.80

29. The high-strength and high-toughness magnesium alloy according to any one of claims 1 to 28, wherein the rare earth element is La or Ce.

30. The high-strength, high-toughness magnesium alloy according to any one of claims 5 to 28, wherein a cooling rate at the time of rapidly solidifying the molten metal is 3.5 × 10 ⁴ KZ seconds or more.

3 1. The high-strength, high-toughness magnesium alloy according to any one of claims 5 to 28, wherein a cooling rate at the time of rapidly solidifying the molten metal is 7 × 10 ⁴ Κ / sec or more.

3 2. The high-strength and high-toughness magnesium alloy according to any one of claims 5 to 28, wherein the spherical compound is an Mg-Zn-rare earth element-based precipitate.

33. The high-strength, high-toughness magnesium alloy according to any one of claims 5 to 32, wherein a segregation layer having a thickness of 100 nm or less is provided at a cell boundary or a crystal grain boundary.

34. The high-strength, high-toughness magnesium alloy according to claim 33, wherein the segregation layer contains Mg, Zn, and a rare earth element system.

35. The high-strength high-toughness magnesium alloy according to claim 33 or 34, wherein the total volume fraction of the spherical compound and the segregation layer is 3.6% or more and 17% or less.

3 6. In any one of claims 5 to 34, the total content of rare earth elements is 1.8 atoms. /. High strength high toughness magnesium alloy which is below.

3 7. The high-strength and high-toughness magnesium alloy according to any one of claims 5 to 28, wherein the width of the cell or the crystal grain is 500 nm or less.

38. Contains & at% of ∑11, contains at least one rare earth element selected from the group consisting of La, Ce and Mm in total at%, and the balance consists of Mg, and a and b are Manufacture of a high-strength, high-toughness magnesium alloy having a process of rapidly solidifying a molten metal satisfying the following formulas (1) to (3) at a cooling rate of 3.δΧ ί ί ^ Κ / sec or more to produce a rapidly solidified product. Method.

(1) 0.2≤a≤3.0 (2) 0.3 ≤ b≤ 1.8

(3)-0.2 a + 0.55 ≤ b≤-0.2 a + 1.95

39. contains & at% of Zn, contains at least b at% of at least one rare earth element selected from the group consisting of La, Ce and Mm, with the balance being Mg, a and b Is a high-strength, high-toughness magnesium alloy that has a process of rapidly solidifying a molten metal satisfying the following formulas (1) to (3) at a cooling rate of 3.5Χ10 ⁴ Κ / sec or more to produce a rapidly solidified product. Production method.

(1) 0.2≤a≤3.0

(2) 0.3 ≤ b≤ 1.8

(3) -0.2 a + 0.55 ≤ b≤-0.2 a + 1.80

40. Contains & 11% by atom, contains at least one rare earth element selected from the group consisting of La, Ce and Mm in total of b atom%, and contains Si, Gd, Dy, Tb, At least one metal selected from the group consisting of Ho, Er, Ca, Mn, Ag, Li, Zr, Th, Y, Yb, Eu, Pr, Sm, and Nd in total of 0 Above 1.8% by atom, with the balance being Mg, a and b quenched molten metal satisfying the following formulas (1) to (3) at a cooling rate of 3.5 X 10 ⁴ KZ seconds or more A method for producing a high-strength, high-toughness magnesium alloy comprising a step of solidifying to produce a rapidly solidified product.

(1) 0.2≤a≤3.0

(2) 0.3 ≤ b ≤ l. 8

(3)-0.2 a + 0.55 ≤ b≤-0.2 a + 1.95

41. It contains & atomic% of Zn, and contains b atomic% in total of at least one rare earth element selected from the group consisting of La, Ce and Mm, and contains Si, Gd, Dy,

At least one metal selected from the group consisting of Tb, Ho, Er, Ca, Mn, Ag, Li, Zr, Th, Y, Yb, Eu, Pr, Sm and Nd in total Exceeds 0 atomic% and contains 1.8 atomic% or less, with the balance being Mg. A and b are melts satisfying the following formulas (1) to (3) at a cooling rate of 3.5 X 10 ⁴ KZ seconds or more. High-strength, high-toughness magnesium with a process of rapidly solidifying to produce a rapidly solidified product Alloy manufacturing method.

(1) 0.2≤a≤3.0

(2) 0.3 ≤ b≤ 1.8

(3) -0.2 a + 0.55≤ b≤- 0.2 a + 1.80

42. Contains & at% of Zn, at least b at% of at least one rare earth element selected from the group consisting of La, Ce and Mm, with the balance consisting of Mg, a and b Is a method for producing a high-strength, high-toughness magnesium alloy comprising a step of rapidly solidifying a molten metal satisfying the following formulas (1) to (3) at a cooling rate of 7 × 10 ⁴ K / sec or more to produce a rapidly solidified product. .

(1) 0.2≤a≤3.0

(2) 0.3 ≤ b≤ 1.8

(3) -0.2 a + 0.55 ≤ b≤-0.2 a + 1.95

43. It contains a atomic% of Zn and at least b atomic% of at least one rare earth element selected from the group consisting of La, Ce and Mm, with the balance being Mg, b is a method for producing a high-strength, high-toughness magnesium alloy comprising a step of rapidly solidifying a molten metal satisfying the following formulas (1) to (3) at a cooling rate of 7 × 10 ⁴ K / sec or more to produce a rapidly solidified product. .

(1) 0.2≤a≤3.0

(2) 0.3 ≤ b≤ 1.8

(3) -0.2 a + 0.55≤b≤ ~ 0.2 a + l. 80

44. Zn is a atom. / ₀ , and at least one rare earth element selected from the group consisting of La, Ce and Mm in a total of 1) atomic%, and Si, Gd, Dy, Tb, Ho, and Er. , Ca, Mn, Ag, Li, Zr, Th, Y, Yb, Eu, Pr, Sm, and Nd. 8% by atom or less, with the balance being Mg, a and b are quenched and solidified at a cooling rate of 7 × 10 ⁴ KZ seconds or more for molten metal that satisfies the following formulas (1) to (3). A method for producing a high-strength, high-toughness magnesium alloy comprising a step of making. (1) 0.2≤a≤3.0

(2) 0.3 ≤ b≤ 1.8

(3) — 0.2 a + 0.55≤ b≤- 0.2 a + 1.95

45. Contains & at.% Of Zn and has b atoms in total of at least one rare earth element selected from the group consisting of La, Ce, and Mm. / ₀ containing, group consisting of Si, Gd, Dy, Tb, Ho, Er, Ca, Mn, Ag, Li, Zr, Th, Y, Yb, Eu, Pr, Sm and Nd Total of at least one metal selected from the group consisting of more than 0 atomic% and 1.8 atomic atoms. / ₀ or less, the balance is made of Mg, and a and b are quenched and solidified at a cooling rate of 7 X 10 ⁴ KZ seconds or more to produce a quenched solid A method for producing a high-strength, high-toughness magnesium alloy comprising a process.

(1) 0.2≤a≤3.0

(2) 0.3 ≤ b≤ 1.8

(3) — 0.2 a + 0.55≤ b≤- 0.2 a + 1.80

46. The high-strength and toughness according to any one of claims 38 to 45, further comprising, after the step of forming the rapidly solidified product, a step of plastically processing the rapidly solidified product to form a plastic processed product. Manufacturing method of magnesium alloy.

47. The method according to any one of claims 38 to 45, wherein after the step of forming the quenched solid, the step of preforming the quenched solid to form a preform, and A method for producing a high-strength, high-toughness magnesium alloy, further comprising a step of forming a plastic workpiece by processing.

48. The method for producing a high-strength and high-toughness magnesium alloy according to claim 47, further comprising, after the step of forming the plastic work product, a step of performing a second plastic work on the plastic work product.

49. The method for producing a high-strength, high-toughness magnesium alloy according to claim 47 or 48, wherein the preforming is compression molding or canning.

50. The method according to any one of claims 46 to 49, wherein the plastic working is extrusion, rolling, E

High strength 髙 tough magnesium alloy that is at least one of CAE and forging 6S

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