JP2019202532A - Hard-soft laminate structural material and method for producing the same - Google Patents

Abstract

To provide a hard-soft laminate structural material having higher strength than that of the original materials.SOLUTION: An embodiment of this invention is a hard-soft laminate structural material, which is a material having a structure in which a plurality of hard layers and a plurality of soft layers are alternately laminated, the soft layer being thicker than the hard layer, the soft layer having a thickness of 1 μm or less.SELECTED DRAWING: None

Description

  The present invention relates to a hard / soft laminated structure material and a method for producing the same.

  Magnesium alloys are rapidly spreading in mobile phone and notebook PC casings and automotive parts. High strength is required for magnesium alloys for use in these applications.

  KUMADAI Magnesium Alloy is attracting attention as a next-generation high-strength magnesium alloy because it has mechanical strength and heat resistance that overturn conventional wisdom and has a high ignition temperature, and research and development is being promoted as a material for transport equipment and medical equipment. Yes. The source of strengthening of KUMADAI heat-resistant magnesium alloy is long-period laminated structure (LPSO structure) and its kink formation. These are the structural and material strengthening methods first discovered in KUMADAI magnesium alloy.

  The “LPSO structure” of LPSO type magnesium alloy has a structure in which hard layers and soft laminates are densely and orderly laminated in an atomic order. Since the hard layers (consisting of heavy additive elements) are densely stacked, the additive elements increase, so that the specific gravity of the LPSO-type magnesium alloy becomes relatively heavy (see, for example, Patent Documents 1 and 2).

  When a strengthening method such as the above KUMADAI magnesium alloy is found, the range of application of the material will be expanded and it will contribute to the dramatic development of the industry. Therefore, there is always a need for new strengthening methods for materials that can be stronger than the original materials. It has been.

WO2005 / 052203 publication WO2005 / 052204

  An object of one embodiment of the present invention is to provide a hard / soft laminated structure material whose strength is higher than that of the original material or a method for manufacturing the same.

Various aspects of the present invention will be described below.
[1] A material having a structure in which a plurality of hard layers and soft layers are alternately laminated,
The soft layer is thicker than the hard layer,
A hard / soft laminated material, wherein the soft layer has a thickness of 1 μm or less.
[2] In the above [1],
The material is a hard / soft laminated material characterized in that the material is a kink-deforming substance.
[3] In the above [1] or [2],
A hard / soft laminated material, wherein kinks are formed in the hard layer and the soft layer.

[4] The hard / soft laminated material according to [3] has higher strength than the hard / soft laminated material according to [1] in which the kink is not formed. Laminated structure material.

[5] In any one of [1] to [4] above,
The soft layer is filled with no gap between the hard layers,
A hard / soft laminated material characterized in that slip deformation or shear deformation of the soft layer when plastically deforming the material is limited to a layer surface of the soft layer.

[6] In any one of [1] to [5] above,
A hard / soft laminated material, wherein the material is any one of a metal, a ceramic, and a polymer.

[7] In any one of the above [1] to [6],
A hard / soft laminated material, wherein the hard layer has a thickness of 100 nm or less.

[8] In any one of the above [1] to [7],
A hard / soft laminated material, wherein the thickness of the hard layer is ½ or less of the thickness of the soft layer.

[9] In any one of [1] to [8] above,
The hard / soft laminated material is characterized in that the hard layer is composed of a plate-like layer in which thin soft layers and thin hard layers are alternately laminated.

[10] In the above [9],
A hard / soft laminated material, wherein each of the thin soft layer and the thin hard layer has a thickness of 10 nm or less.

[11] The hard / soft laminated structure material according to any one of [1] to [10] is a metal-based material,
A hard / soft laminated material, wherein the crystal structure of the hard layer is different from the crystal structure of the soft layer.

[12] The hard / soft laminated structure material according to any one of [1] to [10] is a metal-based material,
The crystal structure of the hard layer and the soft layer is the same,
A hard / soft laminated material, wherein a solute element concentration of the hard layer is different from a solute element concentration of the soft layer.
When the solute element concentration of the hard layer is different from the solute element concentration of the soft layer, metal-based materials having the same crystal structure and no concentration modulation are excluded.

[13] The hard / soft laminated structure material according to any one of [1] to [10] is a metal material,
The hard layer has one of an hcp structure and a bcc structure;
A hard / soft laminate material, wherein the soft layer has the other of an hcp structure and a bcc structure.

[14] The hard / soft laminated structure material according to any one of [1] to [10] is a metal-based material,
The hard layer has one of an hcp structure and an fcc structure;
A hard / soft laminated material, wherein the soft layer has the other of an hcp structure and an fcc structure.

[15] The hard / soft laminated material according to any one of [1] to [10] is a metal-based material,
The hard layer has one of an fcc structure and a bcc structure;
A hard / soft laminate material, wherein the soft layer has the other of an fcc structure and a bcc structure.

[16] The hard / soft laminated material according to [14] is a Mg alloy.

[17] In the above [16],
The Mg alloy includes Mg—Zn—Y alloy, Mg—Zn—Gd alloy, Mg—Zn— (Y—Gd) alloy, Mg—Zn—Y—X—Z alloy, Mg—Zn—Gd—X—Z. Alloy, or Mg-Zn-Y-Gd-XZ alloy,
X is at least one element selected from the group consisting of Al, Ca and Li;
Z is at least one element selected from the group consisting of rare earth elements, Mn, Si, Zr, Ti, Hf, Nb, Sn, Ag, Sr, Sc, Sb, B, C, and Be;
The Zn content is a atomic%, the Y content is b atomic%, the Gd content is b atomic%, the total content of Y and Gd is b atomic%, and the X content is c. A hard / soft laminated structure material satisfying the following (formula 1) to (formula 6) when the atomic percent and the Z content are d atomic percent.
(Formula 1) 0.1 ≦ a ≦ 3.0
(Formula 2) 0.1 ≦ b ≦ 3.0
(Formula 3) c ≦ 3.0
(Formula 4) d ≦ 1.0
(Formula 5) b ≦ a + 2
(Formula 6) b ≧ a−1
The rare earth element is meant to include all rare earth elements.

[18] having a step of casting a metal;
The metal after casting has a structure in which a plurality of hard layers and soft layers are alternately laminated,
The soft layer is thicker than the hard layer,
The method for producing a hard / soft laminated structure material, wherein the soft layer has a thickness of 1 μm or less.

[19] In the above [18],
A method for producing a hard / soft laminated structure material, wherein a cooling rate during casting is less than 100,000 ° C./second.
[20] In the above [19],
A method for producing a hard / soft laminated material, comprising a step of heating the cast metal to a temperature of 50% or more of a melting point (absolute temperature) after the casting step.
[21] In the above [19] or [20],
A method for producing a hard / soft laminated structure material, wherein a cooling rate during casting is 100 ° C./second or more.

[22] In any one of [18] to [21] above,
The metal is Mg—Zn—Y alloy, Mg—Zn—Gd alloy, Mg—Zn— (Y—Gd) alloy, Mg—Zn—Y—X—Z alloy, Mg—Zn—Gd—X—Z alloy. And Mg—Zn—Y—Gd—X—Z alloy,
X is at least one element selected from the group consisting of Al, Ca and Li;
Z is at least one element selected from the group consisting of rare earth elements, Mn, Si, Zr, Ti, Hf, Nb, Sn, Ag, Sr, Sc, Sb, B, C, and Be;
The Zn content is a atomic%, the Y content is b atomic%, the Gd content is b atomic%, the total content of Y and Gd is b atomic%, and the X content is c. A method for producing a hard / soft laminated material characterized by satisfying the following (formula 1) to (formula 6) when the atomic percent and the Z content are d atomic percent.
(Formula 1) 0.1 ≦ a ≦ 3.0
(Formula 2) 0.1 ≦ b ≦ 3.0
(Formula 3) c ≦ 3.0
(Formula 4) d ≦ 1.0
(Formula 5) b ≦ a + 2
(Formula 6) b ≧ a−1

[23] In any one of [18] to [22] above,
The soft layer is filled with no gap between the hard layers,
A method for producing a hard / soft laminated material, wherein slip deformation or shear deformation of the soft layer when the material is plastically deformed is limited to a layer surface of the soft layer.

[24] In any one of [18] to [23] above,
A method for producing a hard / soft laminated material, wherein a cooling rate in producing the magnesium alloy casting is 1000 K / second or less (preferably 100 K / second or less).

[25] The hard / soft laminated structure material according to any one of [1] to [8] is a polymer material,
A hard / soft laminated structure material, wherein the hard layer is a crystalline layer and the soft layer is an amorphous layer.

[26] In the above [25],
The polymer material includes a crystalline polymer, a blend of the first crystalline polymer and the second crystalline polymer, a blend of the crystalline polymer and the polymer, and the first polymer. A hard / soft laminate material characterized in that it is one of blends obtained by mixing a second polymer.

[27] The hard / soft laminated material according to any one of [1] to [8] is a polymer material,
A hard / soft laminated material, wherein the hard layer is an amorphous layer and the soft layer is an amorphous layer.

[28] In the above [27],
The polymer material may be any of a polymer, a blend obtained by mixing the first polymer with the second polymer, and a polymer blend obtained by phase-separating a component polymer having a high elastic modulus and a component polymer having a low elastic modulus. A hard / soft laminated material characterized by

[29] In any one of [25] to [28] above,
Polymers that are constituent components of the polymer material include polypropylene, polyethylene, polybutene 1, polyvinylidene fluoride, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyphenylene sulfide, polysulfone, polyethylene oxide, Polylactic acid, nylon, polystyrene, polycarbonate, polymethyl methacrylate and its copolymer, polyvinyl chloride, phenol resin, polyether ketone, polybutadiene, polyisoprene, polystyrene-polybutadiene copolymer, polyacrylonitrile-polystyrene copolymer, And a hard / soft laminated material comprising at least one of polyacrylonitrile-polybutadiene copolymer.

[30] A crystalline polymer, a blend of the first crystalline polymer and the second crystalline polymer, a blend of the crystalline polymer and the polymer, and the first polymer and the second polymer (A) preparing a polymer material of any one of a blend, a polymer, and a polymer blend obtained by phase-separating a component polymer having a high elastic modulus and a component polymer having a low elastic modulus.
(B) performing plastic working on the polymer material at a temperature higher than room temperature;
Comprising
The material after the step (b) has a structure in which a plurality of hard layers and soft layers are alternately laminated,
The soft layer is thicker than the hard layer,
The method for producing a hard / soft laminated structure material, wherein the soft layer has a thickness of 1 μm or less.

[31] In the above [30],
The method (b) is a method for producing a hard / soft laminated structure material, characterized in that the step (b) is a step of performing hot stretching to apply strain of 200% or more to the polymer material.
[32] In the above [30] or [31],
The method for producing a hard / soft laminated material, wherein the hard layer has an oriented molecular chain.

[33] In any one of the above [30] to [32],
A method for producing a hard / soft laminate material, comprising a step (c) of performing plastic working on the material at room temperature after the step (b).

[34] In the above [33],
The step (c) is a step of performing stretching by applying a strain of 10% or more to the material at room temperature, and a method for producing a hard / soft laminated structure material.
[35] In the above [33] or [34],
A kink is formed in the hard layer and the soft layer after the step (c), and the method for producing a hard / soft laminated structure material is provided.

[36] In any one of the above [30] to [35],
The method for producing a hard / soft laminated structure material, wherein a major axis direction of each of the hard layer and the soft layer is a direction intersecting with an extending direction in the step (b).

  According to one embodiment of the present invention, it is possible to provide a hard / soft laminated structure material whose strength is higher than that of the original material or a manufacturing method thereof.

It is a figure for demonstrating the manufacturing method of the hard and soft laminated structure material which concerns on 1 aspect of this invention. It is a figure for demonstrating the manufacturing method of the hard and soft laminated structure material which concerns on 1 aspect of this invention. It is a TEM photograph of Mg _93.5 Ni ₃ Y _3.5 hard-soft layered structure material made of an alloy. It is a diagram showing the results of tensile testing of Mg _93.5 Ni ₃ Y _3.5 hard-soft layered structure material made of an alloy. It is sectional drawing which shows typically an example in case the hard and soft laminated structure material which concerns on 1 aspect of this invention is a magnesium alloy. The figure which shows the relationship between the extrusion ratio and mechanical characteristic (0.2% yield strength) of each Mg ₉₇ Zn ₁ Gd ₂ alloy wrought material of Example (■), Comparative Example 1 (♦), and Comparative Example 2 (●). It is. (A), (B) is a figure for demonstrating the polymer-type hard and soft laminated structure material by an Example.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and it will be easily understood by those skilled in the art that modes and details can be variously changed without departing from the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited to the description of the embodiments below.

[First Embodiment]
In magnesium alloys, we have found that a hard / soft laminated structure in which a hard layer and a soft layer are laminated in the order of submicron is strengthened by kink formation regardless of order or disorder.

  The kink strengthening of this submicron disordered hard / soft laminated structure is not only based on magnesium alloys containing rare earth elements, but also other metal-based materials such as magnesium alloys that do not contain rare earth elements or titanium alloys and aluminum alloys, It can also be applied to ceramic materials, polymer materials and rear new materials.

First, the KUMADAI magnesium alloy will be described.
The source of strengthening of the KUMADAI magnesium alloy is the long-period laminated structure (LPSO structure shown in FIG. 1) and its kink formation. This long-period stacked structure is a structure in which a cluster arrangement layer (hard layer) having 4 atomic faces and an hcp magnesium layer (soft layer) having 1 to 4 atomic faces shown in FIG. And the soft layer has a densely ordered structure. And because of having such a laminated structure, kinks are formed and strengthened by plastic working. As described above, the KUMADAI magnesium alloy is a material having a crystal structure in which hard layers and soft layers are alternately stacked.

  On the other hand, the hard / soft laminated structure material according to one embodiment of the present invention is a material having a structure in which a plurality of hard layers and soft layers are alternately and randomly laminated. This material can be made of, for example, a metal material such as a magnesium alloy, a titanium alloy, or an aluminum alloy, a ceramic material, and a polymer material. “Disorderly stacked” means removing an ordered stacked structure.

  The soft layer may be thicker than the hard layer, and the soft layer may have a thickness of 1 μm or less. Since the thickness of the soft layer is larger than the thickness of the hard layer, an LPSO structure in which a hard layer of 4 atomic layers and a soft layer of 1 to 4 atomic layers are periodically and regularly stacked is not included.

  The hard / soft laminated structure material may be a kink-deforming substance. Further, kinks may be formed on the hard layer and the soft layer. Further, the above-mentioned hard / soft laminated structure material has higher strength than the hard / soft laminated structure material in which kinks are not formed.

  “Kink” means that a hard-worked hard layer is bent, and is a bent / curved part introduced into the hard layer by plastic deformation of the hard layer.

  The soft layer is filled with no gap between the hard layers. Specifically, when the material is strongly processed to form a kink in the hard layer, delamination that causes the hard layer to peel from the soft layer does not occur. Therefore, no gap is formed between the hard layer and the hard layer, and the soft layer is filled with no gap between the hard layers formed with kinks. That is, the hard layer is not peeled from the soft layer.

  In addition, it is preferable that slip deformation or shear deformation of the soft layer when plastically deforming the material is limited to a layer surface of the soft layer. In other words, the easy slip system of crystals when plastically deforming the material is preferably limited to the layer surface of the soft layer.

  Moreover, it is preferable that the thickness of the said hard layer is 100 nm or less. Moreover, it is preferable that the thickness of the said hard layer is 1/2 or less of the thickness of the said soft layer. In addition, the thickness of a soft layer is an interlayer distance (distance between a hard layer and a hard layer) of a hard layer.

  In the hard / soft laminated structure material according to one embodiment of the present invention, the hard layer may be formed of a plate-like layer in which thin soft layers and thin hard layers are alternately stacked. An example of the hard layer here is an LPSO phase in the case of a magnesium alloy. In this case, the thin soft layer is an hcp magnesium layer having 1 to 4 atomic faces, and the thin hard layer is a cluster arrangement layer (hard layer) having 4 atomic faces.

  Moreover, the thickness of each of the thin soft layer and the thin hard layer is preferably 10 nm or less. When the hard / soft laminated structure material is a metal material, it is preferable that the crystal structure of the hard layer is different from the crystal structure of the soft layer.

  When the hard / soft laminated material is a metal-based material, the hard layer and the soft layer have the same crystal structure, and the solute element concentration of the hard layer is equal to the solute element concentration of the soft layer. And are preferably different. This excludes metal-based materials having the same crystal structure and no concentration modulation. Concentration modulation means that the concentration of a solute element changes periodically every several atomic layers.

  When the hard / soft laminated material is a metal material, the hard layer may have one of an hcp structure and a bcc structure, and the soft layer may have the other of an hcp structure and a bcc structure.

  When the hard / soft laminated material is a metal-based material, the hard layer may have one of an hcp structure and an fcc structure, and the soft layer may have the other of an hcp structure and an fcc structure.

  When the hard / soft laminated material is a metal-based material, the hard layer may have one of an fcc structure and a bcc structure, and the soft layer may have the other of an fcc structure and a bcc structure.

The hard / soft laminated material may be an Mg alloy. This Mg alloy includes Mg—Zn—Y alloy, Mg—Zn—Gd alloy, Mg—Zn— (Y—Gd) alloy, Mg—Zn—Y—X—Z alloy, Mg—Zn—Gd—X—Z. It may be either an alloy or an Mg—Zn—Y—Gd—X—Z alloy. X is at least one element selected from the group consisting of Al, Ca and Li, and Z is a rare earth element, Mn, Si, Zr, Ti, Hf, Nb, Sn, Ag, Sr, Sc And at least one element selected from the group consisting of Sb, B, C and Be. The Zn content is a atomic%, the Y content is b atomic%, the Gd content is b atomic%, the total content of Y and Gd is b atomic%, and the X content is c. When the atomic% and the Z content are d atomic%, the following (formula 1) to (formula 6) may be satisfied.
(Formula 1) 0.1 ≦ a ≦ 3.0
(Formula 2) 0.1 ≦ b ≦ 3.0
(Formula 3) c ≦ 3.0
(Formula 4) d ≦ 1.0
(Formula 5) b ≦ a + 2
(Formula 6) b ≧ a−1
The rare earth element is meant to include all rare earth elements.
Further, the Mg alloy may contain impurities that do not affect the alloy characteristics.

  In the hard / soft laminated structure material according to the present embodiment, the strength can be made higher than that of the original material. The original material means a material having the same composition and generally used conventionally.

  When the above-mentioned hard / soft laminated material is a magnesium alloy, the single cluster arrangement layer (hard layer consisting of four atomic planes) shown in FIG. 1 is sparsely and randomly deposited in the soft hcp magnesium matrix. By forming kinks in the hard / soft laminate structure, the magnesium alloy is strengthened. Compared to LPSO structures such as KUMADAI magnesium alloy, this hard layer cluster arrangement layer, which is a sparsely layered structure, can reduce the amount of elements added to magnesium, thus reducing the weight and cost of the alloy. Can be achieved.

  In other words, a hard / soft laminated structure in which a single cluster arrangement layer (a hard layer consisting of four atomic planes) is sparsely and randomly deposited in a soft hcp magnesium matrix on a magnesium alloy with the same composition as the KUMADAI magnesium alloy When kink is formed in, the strength can be made higher than that of the KUMADAI magnesium alloy having the same composition (this will be described later with reference to FIG. 2). Therefore, even if kinks are formed in a hard / soft laminate structure in which a single cluster arrangement layer is sparsely and randomly deposited in a soft hcp magnesium matrix in a magnesium alloy with a reduced amount of additive elements than the KUMADAI magnesium alloy It is possible to develop almost the same strength as the KUMADAI magnesium alloy with a large amount of added elements. Therefore, the weight and cost of the alloy can be reduced.

  FIG. 5 is a cross-sectional view schematically showing an example of the case where the hard / soft laminated material is a magnesium alloy. The magnesium alloy shown in FIG. 5 is one in which kinks are formed in a hard / soft laminated structure in which cluster arrangement layers SF are sparsely and randomly laminated in soft α-Mg.

[Second Embodiment]
A method for manufacturing a hard / soft laminated structure material according to one embodiment of the present invention will be described. This hard / soft laminated material is a metal-based material.

First, prepare a metal. This metal includes Mg—Zn—Y alloy, Mg—Zn—Gd alloy, Mg—Zn— (Y—Gd) alloy, Mg—Zn—Y—X—Z alloy, Mg—Zn—Gd—X—Z alloy. , And Mg—Zn—Y—Gd—X—Z alloy. X is at least one element selected from the group consisting of Al, Ca and Li, and Z is a rare earth element, Mn, Si, Zr, Ti, Hf, Nb, Sn, Ag, Sr, Sc And at least one element selected from the group consisting of Sb, B, C and Be. The Zn content is a atomic%, the Y content is b atomic%, the Gd content is b atomic%, the total content of Y and Gd is b atomic%, and the X content is c. When the atomic% and the Z content are d atomic%, the following (formula 1) to (formula 6) are satisfied.
(Formula 1) 0.1 ≦ a ≦ 3.0
(Formula 2) 0.1 ≦ b ≦ 3.0
(Formula 3) c ≦ 3.0
(Formula 4) d ≦ 1.0
(Formula 5) b ≦ a + 2
(Formula 6) b ≧ a−1

  Next, the metal is cast. The cast metal has a structure in which a plurality of hard layers and soft layers are alternately laminated. The thickness of the soft layer is thicker than the thickness of the hard layer, and the thickness of the soft layer is 1 μm or less. .

  Even when the metal after the casting does not have the above structure, the metal having the above structure is formed by heating the metal to a temperature of 50% or more of the melting point (absolute temperature) after the casting. Is done. The hard layer is a cluster arrangement layer, and the soft layer is an hcp magnesium layer.

  The cooling rate during the casting is preferably less than 100,000 ° C./second, and preferably 100 ° C./second or more and less than 100,000 ° C./second. Further, the cooling rate at the time of casting may be 1000 K / second or less.

  The metal manufactured by the above manufacturing method has the characteristics described in the first embodiment.

[Third Embodiment]
1 and 2 are diagrams for explaining a method of manufacturing a hard / soft laminated structure material according to one embodiment of the present invention.

First, an Mg ₉₇ Zn ₁ Gd ₂ alloy material is prepared. In the present embodiment, an Mg ₉₇ Zn ₁ Gd ₂ alloy is used. However, the present invention is not limited to this alloy, and a magnesium alloy having any one of the following compositions [1] to [11] can also be used. . These magnesium alloys are called “Type-II” of KUMADAI magnesium alloy.

[1] The magnesium alloy contains a atom% of Zn, contains a total of b atom% of at least one element selected from the group consisting of Gd, Tb, Tm, and Lu, with the balance being Mg and inevitable impurities It is preferable that a and b satisfy the following (formula 41) to (formula 43) or (formula 44) to (formula 46).
(Formula 41) 0.1 ≦ a ≦ 5.0
(Formula 42) 0.25 ≦ b ≦ 5.0
(Formula 43) 0.5a−0.5 ≦ b
(Formula 44) 0.1 ≦ a ≦ 3.0
(Formula 45) 0.25 ≦ b ≦ 5.0
(Formula 46) 2a-3 ≦ b
In addition, the more preferable upper limit content of Gd is less than 3 atomic% in consideration of the increase in economy and specific gravity.

[2] The magnesium alloy contains a atom% of Zn, contains a total of b atom% of at least one element selected from the group consisting of Gd, Tb, Tm, and Lu, with the balance being Mg and inevitable impurities It is preferable that a and b satisfy the following (formula 41 ′), (formula 42 ′) and (formula 43) or (formula 44 ′), (formula 45 ′) and (formula 46).
(Formula 41 ′) 0.2 ≦ a ≦ 5.0
(Formula 42 ′) 0.5 ≦ b ≦ 5.0
(Formula 43) 0.5a−0.5 ≦ b
(Formula 44 ′) 0.2 ≦ a ≦ 3.0
(Formula 45 ′) 0.5 ≦ b ≦ 5.0
(Formula 46) 2a-3 ≦ b

[3] The magnesium alloy according to the above [1] or [2] further contains at least one element selected from the group consisting of Yb, Sm and Nd in total c atom%, and c is the following: (Expression 47) and (Expression 48) should be satisfied.
(Formula 47) 0 ≦ c ≦ 3.0
(Formula 48) 0.25 (0.5) ≦ b + c ≦ 6.0

[4] The magnesium alloy according to the above [1] or [2] further contains at least one element selected from the group consisting of La, Ce, Pr, Eu and Mm in total c atom%, c should satisfy the following (formula 49) and (formula 50).
(Formula 49) 0 ≦ c ≦ 2.0
(Formula 50) 0.25 (0.5) ≦ b + c ≦ 6.0

[5] The magnesium alloy according to the above [1] or [2] further contains at least one element selected from the group consisting of Yb, Sm and Nd in total c atom%, and La, Ce, It is preferable that at least one element selected from the group consisting of Pr, Eu, and Mm is contained in a total of d atomic%, and c and d satisfy the following (formula 51) to (formula 53).
(Formula 51) 0 ≦ c ≦ 3.0
(Formula 52) 0 ≦ d ≦ 2.0
(Formula 53) 0.25 (0.5) ≦ b + c + d ≦ 6.0

[6] In the magnesium alloy according to any one of [1] to [5], the total amount of at least one element selected from the group consisting of Dy, Ho, and Er is more than 0 atomic%. It is good to contain 5 atomic% or less.

[7] The magnesium alloy according to any one of [1] to [5] may further contain Y in an amount of more than 0 atomic% and not more than 1.0 atomic%.

[8] The magnesium alloy according to any one of [1] to [7], further comprising at least one element selected from the group consisting of Gd, Tb, Tm, and Lu in total less than 3 atomic% It is good to contain.

[9] The magnesium alloy according to any one of [1] to [8], further includes Al, Th, Ca, Si, Mn, Zr, Ti, Hf, Nb, Ag, Sr, Sc, B, and It is preferable to contain at least one element selected from the group consisting of C more than 0 atomic% and 2.5 atomic% or less in total.

[10] The magnesium alloy contains Zn by a atom%, and contains at least one element of Gd and Tb by b atom% in total, Al, Y, La, Ce, Pr, Nd, Sm, Dy, Ho, An alloy containing at least one element selected from the group consisting of Er, Tm, and Yb in a total amount of c atomic%, with the balance being Mg and inevitable impurities, wherein a, b, and c are represented by the following formula (Formula 81 ) To (Equation 84) should be satisfied.
(Formula 81) 0.2 ≦ a ≦ 5.0
(Formula 82) 0.2 ≦ b ≦ 5.0
(Formula 83) 2a-3 ≦ b
(Formula 84) 0.05b ≦ c <0.75b

[11] The magnesium alloy wire is an alloy containing Al at a atom%, Gd at b atom%, the balance being Mg and inevitable impurities, wherein a and b are the following (formula 91) and ( Equation 92) should be satisfied.
(Formula 91) 0.01 ≦ a ≦ 2.0
(Formula 92) 0.2 ≦ b ≦ 5.0

Next, the Mg ₉₇ Zn ₁ Gd ₂ alloy is melted and cast to make a magnesium alloy casting. The cooling rate during casting may be 1000 K / sec or less, or 100 K / sec or less. As this magnesium alloy casting, what was cut out into a predetermined shape from an ingot is used. This magnesium alloy casting has α-Mg and Mg ₃ Gd, but no cluster alignment layer is formed. Therefore, as shown in FIG. 2, the yield strength (0.2% yield strength) of the magnesium alloy casting is about 290 MPa.

  Next, the magnesium alloy casting is subjected to a solution treatment. Next, the magnesium alloy casting is subjected to heat treatment. The heat treatment conditions at this time are preferably in the range of “SF” in the T-T-T Diagram shown in FIG. Specifically, the heat treatment conditions are such that the temperature is 300 ° C. or higher (preferably 350 ° C. or higher) and 20 ° C. lower than the melting point, and the processing time is 0.1 hour or longer and 100 hours or shorter. This heat treatment forms a crystal structure in which a plurality of cluster arrangement layers (hard layers) and hcp magnesium layers (soft layers) are alternately stacked on the magnesium alloy. The thickness of the soft layer is larger than the thickness of the hard layer, and the thickness of the soft layer is preferably 1 μm or less.

  Next, the magnesium alloy casting is subjected to plastic working at a temperature of 300 ° C. or higher and 450 ° C. or lower. Examples of the plastic working method include extrusion, ECAE (equal-channel-angular-extrusion) processing, rolling, drawing, forging, pressing, rolling, bending, FSW (friction stir welding), These repeated processes are used.

  Kinks are formed in the hard layer and the soft layer by the plastic processing described above. That is, a plastic workpiece subjected to plastic working has kink deformation.

  In the plastic workpiece, a cluster arrangement layer as a hard layer and an hcp magnesium layer as a soft layer are randomly stacked, and the cluster arrangement layer has kink deformation. In other words, kinks are formed in a hard / soft laminated structure in which hard cluster arrangement layers are sparsely and randomly deposited in a soft hcp magnesium matrix. Thereby, as shown in FIG. 2, the yield strength of the magnesium alloy (plastic workpiece) can be increased to about 380 MPa. In addition, as long as this plastic workpiece has a structure in which a hard layer and a soft layer are randomly stacked, a long-period stacked structure phase (LPSO) may be formed on the plastic workpiece. Further, the plastic workpiece obtained with a yield strength of 380 MPa shown in FIG. 2 is subjected to extrusion with an extrusion ratio of 10 at a temperature of 623K.

Further, as shown in FIG. 2, the yield strength of the KUMADAI magnesium alloy (long-period laminated structure and kink formation) having the same composition as the plastic workpiece is about 350 MPa. The KUMADAI magnesium alloy manufacturing method is different from the above-mentioned plastic work product only in heat treatment conditions when heat-treating the magnesium alloy casting, and this heat treatment condition is “14H-LPSO phase” of TTT Diagram shown in FIG. The range of the
Therefore, the above-mentioned plastic workpiece can be made stronger than the KUMADAI magnesium alloy.

FIG. 6 shows the extrusion ratio and mechanical properties (0.2% proof stress) of the Mg ₉₇ Zn ₁ Gd ₂ alloy wrought material of each of Example (■), Comparative Example 1 (♦), and Comparative Example 2 (●). Showing the relationship.

In Comparative Example 1 (♦), a Mg ₉₇ Zn ₁ Gd ₂ alloy is melted and cast to make a magnesium alloy casting. Next, the casting was extruded at a temperature of 350 ° C. The extrusion ratios at that time were 6, 10, and 15. Next, tensile tests were performed on the extruded products having extrusion ratios of 6, 10, and 15, and the results are shown in FIG.

In Comparative Example 2 (●), a Mg ₉₇ Zn ₁ Gd ₂ alloy is melted and cast to make a magnesium alloy casting. Next, the casting is subjected to heat treatment. The heat treatment conditions at this time are a temperature of 500 ° C. and a treatment time of 10 hours. By this heat treatment, a long-period laminated structure phase is formed, and a KUMADAI magnesium alloy is produced. Thereafter, the alloy was extruded at a temperature of 350 ° C. The extrusion ratios at that time were 6, 10, and 15. Next, tensile tests were performed on the extruded products having extrusion ratios of 6, 10, and 15, and the results are shown in FIG.

In Example (■), a Mg ₉₇ Zn ₁ Gd ₂ alloy is melted and cast to make a magnesium alloy casting. Next, the casting is subjected to heat treatment. The heat treatment conditions at this time are a temperature of 400 ° C. and a treatment time of 10 hours. By this heat treatment, a hard / soft laminated material having a structure in which a plurality of hard layers and soft layers are alternately laminated is formed. Thereafter, the alloy was extruded at a temperature of 350 ° C. The extrusion ratios at that time were 6, 10, and 15. Next, tensile tests were performed on the extruded products having extrusion ratios of 6, 10, and 15, and the results are shown in FIG.

  As shown in FIG. 6, the alloy made of the hard / soft laminated material of Example (■) has superior mechanical properties (0.2% proof stress) compared to KUMADAI magnesium alloy of Comparative Example 2 (●). It was confirmed to have.

[Fourth Embodiment]
A method for manufacturing a hard / soft laminated structure material according to one embodiment of the present invention will be described.
First, an Mg _93.5 Ni ₃ Y _3.5 alloy material is prepared. In this embodiment, an Mg _93.5 Ni ₃ Y _3.5 alloy is used, but the present invention is not limited to this alloy, and a magnesium alloy having any one of the following compositions [12] to [18] is used. Is also possible. These magnesium alloys are called “Type-I” of KUMADAI magnesium alloy.

[12] The magnesium alloy contains a total of at least one metal of Cu, Ni, and Co, and is at least one selected from the group consisting of Y, Dy, Er, Ho, Gd, Tb, and Tm. These elements are a total of b atomic%, the balance being Mg and inevitable impurities, and a and b preferably satisfy the following (formula 61) to (formula 63).
(Formula 61) 0.2 ≦ a ≦ 10
(Formula 62) 0.2 ≦ b ≦ 10
(Formula 63) 2 / 3a-2 / 3 <b

[13] The magnesium alloy according to [12] above further contains c atomic% of Zn, and a and c preferably satisfy the following (formula 64).
(Formula 64) 0.2 <a + c ≦ 15

[14] In the above [13], the a and c may further satisfy the following (formula 65).
(Formula 65) c / a ≦ 1/2

[15] The magnesium alloy according to any one of [12] to [14] is further at least one selected from the group consisting of La, Ce, Pr, Nd, Sm, Eu, Yb, and Lu. It is preferable that the element contains d atomic% in total, and the b and d satisfy the following (formula 66).
(Formula 66) 0.2 <b + d ≦ 15

[16] In the above [15], b and d may further satisfy the following (formula 67).
(Formula 67) d / b ≦ 1/2

[17] The magnesium alloy according to any one of [12] to [16], further includes Zr, Ti, Mn, Al, Ag, Sc, Sr, Ca, Si, Hf, Nb, B, C, Containing at least one element selected from the group consisting of Sn, Au, Ba, Ge, Bi, Ga, In, Ir, Li, Pd, Sb, V, Fe, Cr, and Mo in a total of e atomic%, It is preferable that e satisfies the following (Formula 68).
(Formula 68) 0 <e ≦ 2.5

[18] In the above [17], the e, a, b, and d may further satisfy the following (formula 69).
(Formula 69) e / (a + b + c + d) ≦ 1/2

Next, the Mg _93.5 Ni ₃ Y _3.5 alloy is melted and cast to make a magnesium alloy casting. The cooling rate at the time of casting is 0.05 K / second or more and 1000 (10 ³ ) K / second or less, more preferably 0.5 K / second or more and 1000 (10 ³ ) K / second or less, and still more preferably 0.8. 5K / second or more and 100K / second or less. As this magnesium alloy casting, what was cut out into a predetermined shape from an ingot is used. In this magnesium alloy casting, a cluster arrangement layer is formed.

  Next, the magnesium alloy casting is subjected to heat treatment. The heat treatment conditions at this time are preferably a temperature of 300 ° C. or higher (preferably 350 ° C. or higher) and a temperature lower than the melting point by 20 ° C. or lower, and a processing time of 0.1 hours or longer and 100 hours or shorter. This heat treatment forms a crystal structure in which a plurality of cluster arrangement layers (hard layers) and hcp magnesium layers (soft layers) are alternately stacked on the magnesium alloy. The thickness of the soft layer is larger than the thickness of the hard layer, and the thickness of the soft layer is preferably 1 μm or less.

  Next, plastic working is performed on the magnesium alloy casting. Specific examples of this plastic working are as follows.

  When performing plastic working by extrusion, it is preferable that the extrusion temperature is 200 ° C. or more and 500 ° C. or less, and the cross-sectional reduction rate by extrusion is 5% or more.

  The ECAE processing method is a method of rotating the sample longitudinal direction by 90 ° for each pass in order to introduce a uniform strain to the sample. Specifically, a magnesium alloy cast material as a molding material is forcibly entered into the molding hole of the molding die in which a L-shaped molding hole is formed. This is a method of applying a stress to the magnesium alloy casting at a portion bent at a degree to obtain a molded body having excellent strength and toughness. The number of ECAE passes is preferably 1 to 8 passes. More preferably, it is 3 to 5 passes. The temperature during processing of ECAE is preferably 200 ° C. or more and 500 ° C. or less.

  When performing plastic working by rolling, it is preferable that the rolling temperature is 200 ° C. or more and 500 ° C. or less, and the rolling reduction is 5% or more.

  When performing plastic working by drawing, it is preferable that the temperature at the time of drawing is 200 ° C. or more and 500 ° C. or less, and the cross-sectional reduction rate of the drawing is 5% or more.

When performing plastic working by forging, it is preferable that the temperature at the time of forging is 200 ° C. or more and 500 ° C. or less, and the processing rate of the forging is 5% or more.
Moreover, you may use the process accompanying plastic deformation, such as the above-mentioned repetition of plastic processing, FSW (friction stir welding).

  Kinks are formed in the hard layer and the soft layer by the plastic processing described above. That is, a plastic workpiece subjected to plastic working has kink deformation.

In the plastic workpiece, a cluster arrangement layer that is a hard layer and an hcp magnesium layer that is a soft layer are randomly stacked, and the cluster arrangement layer has a kink band. In other words, kinks are formed in a hard / soft laminated structure in which hard cluster arrangement layers are sparsely and randomly deposited in a soft hcp magnesium matrix (see FIG. 3). Thereby, as shown in FIG. 4, the yield strength (σ _0.2 ) of the magnesium alloy (plastic workpiece) can be increased to 512 MPa, and the elongation (δ) can be 8.9%. In addition, as long as this plastic workpiece has a structure in which a hard layer and a soft layer are randomly stacked, a long-period stacked structure phase (LPSO) may be formed on the plastic workpiece. Moreover, the plastic work product in which the structure of the TEM photograph shown in FIG. 3 and the yield strength of 512 MPa shown in FIG. 4 were obtained was subjected to extrusion with an extrusion ratio of 10 at a temperature of 673K.

  Moreover, the yield strength of the KUMADAI magnesium alloy (long-period laminated structure and kink formation) having the same composition as the plastic workpiece subjected to the test shown in FIG. 4 is considerably lower than 512 MPa. The only difference between the KUMADAI magnesium alloy manufacturing method and the plastic workpiece is the heat treatment conditions when the magnesium alloy casting is heat treated.

[Fifth Embodiment]
A method for manufacturing a hard / soft laminated structure material according to one embodiment of the present invention will be described.
First, a magnesium alloy having any one of the following compositions [19] to [40] is prepared. These magnesium alloys are called “Type-I” of KUMADAI magnesium alloy.

[19] The magnesium alloy is an alloy containing Zn at a atom%, Y at b atom%, and the balance being Mg and inevitable impurities, wherein a and b are the following (formula 11) to (formula) 13) or (Expression 14) to (Expression 16) may be satisfied.
(Formula 11) 0.25 ≦ a <5.0
(Formula 12) 0.5 <b <5.0
(Formula 13) 2 / 3a-5 / 6 ≦ b
(Formula 14) 0.25 ≦ a ≦ 5.0
(Formula 15) 0.5 ≦ b ≦ 5.0
(Formula 16) 0.5a ≦ b

[20] The magnesium alloy is an alloy containing Zn at a atom%, Y at b atom%, the balance being Mg and unavoidable impurities, wherein a and b are the following (formula 11 ′), ( It is preferable to satisfy Expression 12) and Expression 13.
(Formula 11 ′) 0.5 ≦ a <5.0
(Formula 12) 0.5 <b <5.0
(Formula 13) 2 / 3a-5 / 6 ≦ b

[21] The magnesium alloy according to the above [19] or [20] further contains at least one element selected from the group consisting of Yb, Tb, Sm and Nd in total c atom%, and c is It is preferable to satisfy the following (Equation 17) and (Equation 18).
(Formula 17) 0 ≦ c ≦ 3.0
(Formula 18) 0.1 (0.2) ≦ b + c ≦ 6.0

[22] The magnesium alloy according to [19] or [20] further includes at least one element selected from the group consisting of La, Ce, Pr, Eu, Mm, and Gd in total c atom% C preferably satisfies the following (formula 19) and (formula 20).
(Formula 19) 0 ≦ c <2.0
(Formula 20) 0.2 ≦ b + c ≦ 6.0

[23] The magnesium alloy according to [19] or [20] further includes at least one element selected from the group consisting of La, Ce, Pr, Eu, Mm, and Gd in total c atom% C preferably satisfies the following (formula 20) and (formula 21).
(Formula 20) 0.2 ≦ b + c ≦ 6.0
(Formula 21) c / b ≦ 1.5

[24] The magnesium alloy according to [19] or [20] further includes at least one element selected from the group consisting of La, Ce, Pr, Eu, Mm, and Gd in total c atom% C preferably satisfies the following (Equation 22) and (Equation 23).
(Formula 22) 0 ≦ c ≦ 3.0
(Formula 23) 0.1 <= b + c <= 6.0

[25] The magnesium alloy according to [19] or [20] described above further includes at least one element selected from the group consisting of Yb, Tb, Sm, and Nd in total c atom%, La, It is preferable that at least one element selected from the group consisting of Ce, Pr, Eu, Mm and Gd is contained in total in d atom%, and c and d satisfy the following (formula 14) to (formula 16).
(Formula 14) 0 ≦ c ≦ 3.0
(Formula 15) 0 ≦ d <2.0
(Formula 16) 0.2 ≦ b + c + d ≦ 6.0

[26] The magnesium alloy according to the above [19] or [20] further contains at least one element selected from the group consisting of Yb, Tb, Sm and Nd in total c atom%, La, It is preferable that at least one element selected from the group consisting of Ce, Pr, Eu, Mm, and Gd is contained in total in d atom%, and c and d satisfy the following (formula 16) and (formula 17).
(Formula 16) 0.2 ≦ b + c + d ≦ 6.0
(Formula 17) d / b ≦ 1.5

[27] The magnesium alloy according to the above [19] or [20] further contains at least one element selected from the group consisting of Yb, Tb, Sm, and Nd in total c atom%, La, It is preferable that at least one element selected from the group consisting of Ce, Pr, Eu, Mm and Gd is contained in total in d atomic%, and c and d satisfy the following (formula 18) to (formula 20).
(Formula 18) 0 ≦ c ≦ 3.0
(Formula 19) 0 ≦ d ≦ 3.0
(Formula 20) 0.1 ≦ b + c + d ≦ 6.0

[28] The magnesium alloy according to any one of [19] to [27], further includes Al, Th, Ca, Si, Mn, Zr, Ti, Hf, Nb, Ag, Sr, Sc, B, A total of at least one element selected from the group consisting of C, Sn, Au, Ba, Ge, Bi, Ga, In, Ir, Li, Pd, Sb and V is more than 0 atom% and less than 2.5 atom% It is good to contain.

[29] The magnesium alloy contains Zn at a atom%, contains at least one element selected from the group consisting of Dy, Ho, and Er in total b atom%, and the balance consists of Mg and inevitable impurities. It is an alloy, and a and b may satisfy the following (formula 21) to (formula 23) or (formula 24) to (formula 26).
(Formula 21) 0.1 ≦ a ≦ 5.0
(Formula 22) 0.1 ≦ b ≦ 5.0
(Formula 23) 0.5a-0.5 <= b
(Formula 24) 0.1 ≦ a ≦ 3.0
(Formula 25) 0.1 ≦ b ≦ 5.0
(Formula 26) 2a-3 ≦ b

[30] The magnesium alloy contains Zn at a atom%, contains at least one element selected from the group consisting of Dy, Ho, and Er in total b atom%, with the balance being Mg and inevitable impurities. In the alloy, a and b may satisfy the following (formula 21 ′), (formula 22 ′) and (formula 23) or (formula 24 ′), (formula 25 ′) and (formula 26).
(Formula 21 ′) 0.2 ≦ a ≦ 5.0
(Formula 22 ′) 0.2 ≦ b ≦ 5.0
(Formula 23) 0.5a-0.5 <= b
(Formula 24 ′) 0.2 ≦ a ≦ 3.0
(Formula 25 ′) 0.2 ≦ b ≦ 5.0
(Formula 26) 2a-3 ≦ b

[31] The magnesium alloy according to [29] or [30] further contains at least one element selected from the group consisting of Yb, Sm, and Nd in total c atom%, and c is the following: (Expression 27) and (Expression 28) should be satisfied.
(Formula 27) 0 ≦ c ≦ 3.0
(Formula 28) 0.1 (0.2) <= b + c <= 6.0

[32] The magnesium alloy according to the above [29] or [30] further contains at least one element selected from the group consisting of La, Ce, Pr, Eu, and Mm in a total of c atomic%, c should satisfy the following (formula 29) and (formula 30).
(Formula 29) 0 ≦ c ≦ 3.0
(Formula 30) 0.1 (0.2) ≦ b + c ≦ 6.0

[33] The magnesium alloy according to the above [29] or [30] further contains at least one element selected from the group consisting of Yb, Sm and Nd in total c atom%, and La, Ce, It is preferable that at least one element selected from the group consisting of Pr, Eu, and Mm is contained in d atom% in total, and c and d satisfy the following (formula 31) to (formula 33).
(Formula 31) 0 ≦ c ≦ 3.0
(Formula 32) 0 ≦ d ≦ 3.0
(Formula 33) 0.1 (0.2) ≦ b + c + d ≦ 6.0

[34] The magnesium alloy according to any one of [29] to [33] described above further contains at least one of Y and Gd in a total of y atomic%, wherein y is represented by the following (Formula 34) and (Formula: 35) should be satisfied.
(Formula 34) 0 ≦ y ≦ 4.9
(Formula 35) 0.1 ≦ b + y ≦ 5.0

[35] The magnesium alloy according to any one of [29] to [34] described above further includes Al, Th, Ca, Si, Mn, Zr, Ti, Hf, Nb, Ag, Sr, Sc, B, A total of at least one element selected from the group consisting of C, Sn, Au, Ba, Ge, Bi, Ga, In, Ir, Li, Pd, Sb and V is more than 0 atom% and less than 2.5 atom% It is good to contain.

[36] The magnesium alloy contains Zn by a atom%, and contains at least one element of Y, Dy, Ho and Er in total b atom%, La, Ce, Pr, Nd, Sm, Gd, Tb and It is an alloy containing at least one element selected from the group consisting of Yb in a total of c atomic% and the balance being Mg and inevitable impurities, wherein a, b and c are the following (formula 71) to (formula 74) should be satisfied.
(Formula 71) 0.2 <= a <= 5.0
(Formula 72) 0.2 ≦ b ≦ 5.0
(Formula 73) 2a-3 ≦ b
(Formula 74) 0.05b ≦ c <0.75b

[37] The magnesium alloy according to [36] may further contain d atomic% of Al and satisfy the following (formula 75).
(Formula 75) 0.05b ≦ d <0.75b

[38] The magnesium alloy according to the above [36] or [37] may contain a total of b atom% of at least two elements of Y, Dy, Ho and Er.

[39] The magnesium alloy contains Zn by a atom%, and contains at least one element selected from the group consisting of Y, Dy, Ho, Er, Gd, Tb and Tm in total b atom%, Al It is preferable that a, b, and c satisfy the following (formula 101) to (formula 104).
(Formula 101) 0.2 ≦ a ≦ 5.0
(Formula 102) 0.2 ≦ b ≦ 5.0
(Formula 103) 2a-3 ≦ b
(Formula 104) 0.05b ≦ c <0.75b

[40] The magnesium alloy according to the above [39] further includes Li, Sn, Di, La, Ce, Pr, Nd, Sm, Eu, Mm, Yb, Th, Ca, Si, Mn, Zr, Ti, At least one element selected from the group consisting of Hf, Nb, Ag, Sr, Sc, B, C, Ga, and Ge is contained in total in d atomic%, and d may satisfy the following (Formula 105). .
(Formula 105) 0 ≦ d ≦ b / 2

  Next, one of the above magnesium alloys is melted and cast to make a magnesium alloy casting. The cooling rate at the time of casting is 1000 K / second or less, more preferably 100 K / second or less. Various processes can be used as the casting process. For example, high pressure casting, roll casting, inclined plate casting, continuous casting, thixo molding, die casting, and the like can be used. Moreover, you may use what cut out the magnesium alloy casting in the predetermined shape. In this magnesium alloy casting, a cluster arrangement layer is formed.

  Next, the magnesium alloy casting is subjected to heat treatment. The heat treatment conditions at this time are preferably a temperature of 300 ° C. or higher (preferably 350 ° C. or higher) and a temperature lower than the melting point by 20 ° C. or lower, and a processing time of 0.1 hours or longer and 100 hours or shorter. This heat treatment forms a crystal structure in which a plurality of cluster arrangement layers (hard layers) and hcp magnesium layers (soft layers) are alternately stacked on the magnesium alloy. The thickness of the soft layer is larger than the thickness of the hard layer, and the thickness of the soft layer is preferably 1 μm or less.

  Next, plastic working is performed on the magnesium alloy casting. Examples of the plastic working method include extrusion, ECAE (equal-channel-angular-extrusion) processing, rolling, drawing, forging, pressing, rolling, bending, FSW (friction stir welding), These repeated processes are used.

  Kinks are formed in the hard layer and the soft layer by the plastic processing described above. That is, a plastic workpiece subjected to plastic working has kink deformation.

  In the plastic workpiece, a cluster arrangement layer that is a hard layer and an hcp magnesium layer that is a soft layer are randomly stacked, and the cluster arrangement layer has a kink band. In other words, kinks are formed in a hard / soft laminated structure in which hard cluster arrangement layers are sparsely and randomly deposited in a soft hcp magnesium matrix. Thereby, the intensity | strength of said plastic workpiece can be made high. In addition, as long as this plastic workpiece has a structure in which a hard layer and a soft layer are randomly stacked, a long-period stacked structure phase (LPSO) may be formed on the plastic workpiece.

[Sixth Embodiment]
A method for manufacturing a hard / soft laminated structure material according to one embodiment of the present invention will be described.

  First, a crystalline polymer, a blend of the first crystalline polymer with the second crystalline polymer, a blend of the crystalline polymer with the polymer, and the second polymer into the first polymer Prepare any polymeric material of the blended blend. Polypropylene, polyethylene, polybutene 1, polyvinylidene fluoride, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyphenylene sulfide, polysulfone, polyethylene oxide , Polylactic acid, nylon, polystyrene, polycarbonate, polymethyl methacrylate and its copolymer, polyvinyl chloride, phenol resin, polyether ketone, polybutadiene, polyisoprene, polystyrene-polybutadiene copolymer, polyacrylonitrile-polystyrene copolymer , And at least one of polyacrylonitrile-polybutadiene copolymers can be used.

  Next, the polymer material is subjected to plastic working at a temperature higher than room temperature. For example, thermal stretching is performed in which a strain of 200% or more (preferably 300% or more, more preferably 400% or more, and still more preferably 500% or more) is applied to the above polymer material. The thermal stretching means stretching in a temperature range higher than room temperature and lower than the melting point of the polymer material.

  The material subjected to the heat stretching has a structure in which a plurality of hard layers and soft layers are alternately laminated, the hard layer is a crystalline layer, and the soft layer is an amorphous layer. And the thickness of a soft layer is thicker than the thickness of a hard layer, and the thickness of a soft layer will be 1 micrometer or less. The hard layer preferably has an oriented molecular chain. Further, this material is a substance that undergoes kink deformation. In addition, the major axis direction of each of the hard layer and the soft layer is preferably a direction that intersects the heat stretching direction (for example, a direction perpendicular to the heat stretching direction).

  Thereafter, this material is plastically processed at room temperature. For example, the material is stretched by 10% or more (preferably 20% or more, more preferably 30% or more, and further preferably 40% or more) at room temperature. Since kinks are formed in the hard layer and soft layer during this plastic working, the increase in strength as seen in work hardening of metal is expressed without increasing the stress (strength) after yielding, and high Both strength and ductility are shown. And the kink is formed in the hard layer and soft layer in the material after extending | stretching. This kink works hardens the material and increases its strength.

  In other words, since the material exhibits work hardening by forming the kink at a low temperature, the strength can be increased by cold working as in the case of metal. Therefore, this material can be applied to material applications made by cold working of metals such as automobile body materials.

  FIGS. 7A and 7B are diagrams for explaining a polymer-based hard / soft laminated structure material according to an example.

  As a sample, a blend of polyvinylidene fluoride (PVDF) / polymethyl methacrylate (PMMA) having a composition of 50/50 was used. PVDF is a crystalline polymer and PMMA is an amorphous polymer.

  The PVDF / PMMA blend sample was hot-pressed in a state of being melted at a melting point or higher of PVDF, and then rapidly cooled to obtain a film sample in which PVDF of the component polymer was crystallized (untreated sample in FIG. 7B) ).

  Next, a hard layer which is a PVDF crystal layer and a soft layer which is a PVDF / PMMA amorphous layer by uniaxial thermal stretching (plastic processing) at 100 ° C. which is lower than the melting point of PVDF (the melting point of PVDF is about 160 ° C.) A hard / soft laminated material having a layered structure in which a plurality of layers are alternately laminated is formed. A strain of 300% or more was applied by this thermal stretching. FIG. 7A shows the relationship between strain (%) and stress (MPa) when this heat stretching is performed. The major axis direction of the layer in this layered structure is oriented in the direction perpendicular to the stretching direction. This can be confirmed from the fact that in the small-angle X-ray scattering measurement, a broad arc-shaped scattered image in the meridian direction is observed. A small angle X-ray scattering image shown in FIG. 7A shows a scattering image by a layered structure. The PVDF crystal (hard layer) has molecular chains oriented in the stretching direction (SD direction).

  In this example, a hard / soft laminated structure material was produced by plastic working by uniaxial thermal stretching, but not only by uniaxial thermal stretching, but also by hard plastic working by general-purpose injection molding machines. It is possible to produce a laminated structure material.

  Thereafter, stretching (tensile test) at room temperature was performed on each of the untreated sample, the sample heat-stretched to a strain of 300%, and the sample heat-stretched to a strain close to 500%. The relationship between the strain (%) and the stress (MPa) is shown in FIG.

The untreated sample as a comparative example, like a general polymer, had a stress sag when the strain increased, and there was no increase in strength after yielding.
On the other hand, the sample heat-stretched to 300% strain, unlike the general polymer stress-strain behavior, showed a breaking strength about 4 times that of the untreated sample.
Samples obtained by hot stretching up to strain of 500% are completely different from the stress-strain behavior of general polymers, and show an increase in stress as seen in work hardening of metals, compared to untreated samples. It was found to show 10 times the breaking strength.

SEM observation of a 500% strained stretch sample showed a clear kink formation, so that a dramatic increase in fracture stress and a unique stress-strain behavior in the 500% stretch sample were observed at room temperature. This is thought to be due to kink formation during stretching.
In addition, although clear kink formation was not observed in the SEM observation of a 300% strain stretched sample, it was considered that kinks were slightly formed from the increase in strength.

  In addition, it was found that the kink-reinforced 500% heat stretched sample is difficult to tear in the stretching direction and suppresses a decrease in strength in the direction perpendicular to the stretching direction. From this, it is expected that the kink-reinforced polymer hard / soft laminated material can be applied to a three-dimensional structural material.

  If the above-mentioned material strengthening method can be applied to polypropylene, it can be expected to be applied to the body of cars and electrical appliances by devising the molding method.

[Seventh Embodiment]
A method for manufacturing a hard / soft laminated structure material according to one embodiment of the present invention will be described.

  First, a polymer, a blend obtained by mixing the first polymer with the second polymer, or a polymer blend obtained by phase-separating a component polymer having a high modulus of elasticity and a component polymer having a low modulus of elasticity. Prepare the materials. As the polymer that is a constituent component of these polymer materials, the same polymers as those in the sixth embodiment can be used.

  Next, plastic processing is performed on the above-described polymer material by the same method as in the sixth embodiment.

  The material subjected to the above plastic working has a structure in which a plurality of hard layers and soft layers are alternately laminated, the hard layer is an amorphous layer, and the soft layer is an amorphous layer. And the thickness of a soft layer is thicker than the thickness of a hard layer, and the thickness of a soft layer will be 1 micrometer or less. Further, this material is a substance that undergoes kink deformation. Further, the major axis direction of each of the hard layer and the soft layer may be a direction that intersects the heat stretching direction, as in the sixth embodiment.

  Thereafter, as in the sixth embodiment, this material is plastically processed at room temperature. Since kinks are formed in the hard layer and soft layer during this plastic working, the increase in strength as seen in work hardening of metal is expressed without increasing the stress (strength) after yielding, and high Both strength and ductility are shown. And the kink is formed in the hard layer and the soft layer in the material after plastic working. This kink works hardens the material and increases its strength.

  It should be noted that the first to seventh embodiments can be implemented in appropriate combination.

Claims (36)

A material having a structure in which a plurality of hard layers and soft layers are alternately laminated,
The soft layer is thicker than the hard layer,
A hard / soft laminated material, wherein the soft layer has a thickness of 1 μm or less. In claim 1,
The material is a hard / soft laminated material characterized in that the material is a kink-deforming substance. In claim 1 or 2,
A hard / soft laminated material, wherein kinks are formed in the hard layer and the soft layer.   The hard / soft laminate structure material according to claim 3, wherein the hard / soft laminate structure material has higher strength than the hard / soft laminate structure material according to claim 1, wherein the kink is not formed. In any one of Claims 1 thru | or 4,
The soft layer is filled with no gap between the hard layers,
A hard / soft laminated material characterized in that slip deformation or shear deformation of the soft layer when plastically deforming the material is limited to a layer surface of the soft layer. In any one of Claims 1 thru | or 5,
A hard / soft laminated material, wherein the material is any one of a metal, a ceramic, and a polymer. In any one of Claims 1 thru | or 6,
A hard / soft laminated material, wherein the hard layer has a thickness of 100 nm or less. In any one of Claims 1 thru | or 7,
A hard / soft laminated material, wherein the thickness of the hard layer is ½ or less of the thickness of the soft layer. In any one of Claims 1 thru | or 8,
The hard / soft laminated material is characterized in that the hard layer is composed of a plate-like layer in which thin soft layers and thin hard layers are alternately laminated. In claim 9,
A hard / soft laminated material, wherein each of the thin soft layer and the thin hard layer has a thickness of 10 nm or less. The hard / soft laminated structure material according to any one of claims 1 to 10 is a metal-based material,
A hard / soft laminated material, wherein the crystal structure of the hard layer is different from the crystal structure of the soft layer. The hard / soft laminated structure material according to any one of claims 1 to 10 is a metal-based material,
The crystal structure of the hard layer and the soft layer is the same,
A hard / soft laminated material, wherein a solute element concentration of the hard layer is different from a solute element concentration of the soft layer. The hard / soft laminated structure material according to any one of claims 1 to 10 is a metal-based material,
The hard layer has one of an hcp structure and a bcc structure;
A hard / soft laminate material, wherein the soft layer has the other of an hcp structure and a bcc structure. The hard / soft laminated structure material according to any one of claims 1 to 10 is a metal-based material,
The hard layer has one of an hcp structure and an fcc structure;
A hard / soft laminated material, wherein the soft layer has the other of an hcp structure and an fcc structure. The hard / soft laminated structure material according to any one of claims 1 to 10 is a metal-based material,
The hard layer has one of an fcc structure and a bcc structure;
A hard / soft laminate material, wherein the soft layer has the other of an fcc structure and a bcc structure.   The hard / soft multilayer structure material according to claim 14 is an Mg alloy. In claim 16,
The Mg alloy includes Mg—Zn—Y alloy, Mg—Zn—Gd alloy, Mg—Zn— (Y—Gd) alloy, Mg—Zn—Y—X—Z alloy, Mg—Zn—Gd—X—Z. Alloy, or Mg-Zn-Y-Gd-XZ alloy,
X is at least one element selected from the group consisting of Al, Ca and Li;
Z is at least one element selected from the group consisting of rare earth elements, Mn, Si, Zr, Ti, Hf, Nb, Sn, Ag, Sr, Sc, Sb, B, C, and Be;
The Zn content is a atomic%, the Y content is b atomic%, the Gd content is b atomic%, the total content of Y and Gd is b atomic%, and the X content is c. A hard / soft laminated structure material satisfying the following (formula 1) to (formula 6) when the atomic percent and the Z content are d atomic percent.
(Formula 1) 0.1 ≦ a ≦ 3.0
(Formula 2) 0.1 ≦ b ≦ 3.0
(Formula 3) c ≦ 3.0
(Formula 4) d ≦ 1.0
(Formula 5) b ≦ a + 2
(Formula 6) b ≧ a−1 Having a process of casting metal,
The metal after casting has a structure in which a plurality of hard layers and soft layers are alternately laminated,
The soft layer is thicker than the hard layer,
The method for producing a hard / soft laminated structure material, wherein the soft layer has a thickness of 1 μm or less. In claim 18,
A method for producing a hard / soft laminated structure material, wherein a cooling rate during casting is less than 100,000 ° C./second. In claim 19,
A method for producing a hard / soft laminated material, comprising a step of heating the cast metal to a temperature of 50% or more of a melting point (absolute temperature) after the casting step. In claim 19 or 20,
A method for producing a hard / soft laminated structure material, wherein a cooling rate during casting is 100 ° C./second or more. In any one of claims 18 to 21,
The metal is Mg—Zn—Y alloy, Mg—Zn—Gd alloy, Mg—Zn— (Y—Gd) alloy, Mg—Zn—Y—X—Z alloy, Mg—Zn—Gd—X—Z alloy. And Mg—Zn—Y—Gd—X—Z alloy,
X is at least one element selected from the group consisting of Al, Ca and Li;
Z is at least one element selected from the group consisting of rare earth elements, Mn, Si, Zr, Ti, Hf, Nb, Sn, Ag, Sr, Sc, Sb, B, C, and Be;
The Zn content is a atomic%, the Y content is b atomic%, the Gd content is b atomic%, the total content of Y and Gd is b atomic%, and the X content is c. A method for producing a hard / soft laminated material characterized by satisfying the following (formula 1) to (formula 6) when the atomic percent and the Z content are d atomic percent.
(Formula 1) 0.1 ≦ a ≦ 3.0
(Formula 2) 0.1 ≦ b ≦ 3.0
(Formula 3) c ≦ 3.0
(Formula 4) d ≦ 1.0
(Formula 5) b ≦ a + 2
(Formula 6) b ≧ a−1 In any one of claims 18 to 22,
The soft layer is filled with no gap between the hard layers,
A method for producing a hard / soft laminated material, wherein slip deformation or shear deformation of the soft layer when the material is plastically deformed is limited to a layer surface of the soft layer. A method according to any one of claims 18 to 23.
The method for producing a hard / soft laminated structure material, wherein a cooling rate during casting is 1000 K / second or less. The hard / soft laminated structure material according to any one of claims 1 to 8 is a polymer material,
A hard / soft laminated structure material, wherein the hard layer is a crystalline layer and the soft layer is an amorphous layer. In claim 25,
The polymer material includes a crystalline polymer, a blend of the first crystalline polymer and the second crystalline polymer, a blend of the crystalline polymer and the polymer, and the first polymer. A hard / soft laminate material characterized in that it is one of blends obtained by mixing a second polymer. The hard / soft laminated structure material according to any one of claims 1 to 8 is a polymer material,
A hard / soft laminated material, wherein the hard layer is an amorphous layer and the soft layer is an amorphous layer. In claim 27,
The polymer material may be any of a polymer, a blend obtained by mixing the first polymer with the second polymer, and a polymer blend obtained by phase-separating a component polymer having a high elastic modulus and a component polymer having a low elastic modulus. A hard / soft laminated material characterized by A device according to any one of claims 25 to 28.
Polymers that are constituent components of the polymer material include polypropylene, polyethylene, polybutene 1, polyvinylidene fluoride, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyphenylene sulfide, polysulfone, polyethylene oxide, Polylactic acid, nylon, polystyrene, polycarbonate, polymethyl methacrylate and its copolymer, polyvinyl chloride, phenol resin, polyether ketone, polybutadiene, polyisoprene, polystyrene-polybutadiene copolymer, polyacrylonitrile-polystyrene copolymer, And a hard / soft laminated material comprising at least one of polyacrylonitrile-polybutadiene copolymer. Crystalline polymer, blend of first crystalline polymer mixed with second crystalline polymer, blend of crystalline polymer mixed with polymer, blended first polymer with second polymer Preparing a polymer material of any one of a blend, a polymer, and a polymer blend in which a component polymer having a high elastic modulus and a component polymer having a low elastic modulus are phase-separated;
(B) performing plastic working on the polymer material at a temperature higher than room temperature;
Comprising
The material after the step (b) has a structure in which a plurality of hard layers and soft layers are alternately laminated,
The soft layer is thicker than the hard layer,
The method for producing a hard / soft laminated structure material, wherein the soft layer has a thickness of 1 μm or less. In claim 30,
The method (b) is a method for producing a hard / soft laminated structure material, characterized in that the step (b) is a step of performing hot stretching to apply strain of 200% or more to the polymer material. In claim 30 or 31,
The method for producing a hard / soft laminated material, wherein the hard layer has an oriented molecular chain. In any one of claims 30 to 32,
A method for producing a hard / soft laminate material, comprising a step (c) of performing plastic working on the material at room temperature after the step (b). In claim 33,
The step (c) is a step of performing stretching by applying a strain of 10% or more to the material at room temperature, and a method for producing a hard / soft laminated structure material. In claim 33 or 34,
A kink is formed in the hard layer and the soft layer after the step (c), and the method for producing a hard / soft laminated structure material is provided. In any one of claims 30 to 35,
The method for producing a hard / soft laminated structure material, wherein a major axis direction of each of the hard layer and the soft layer is a direction intersecting with an extending direction in the step (b).