WO2004085692A1

WO2004085692A1 - PROCESS OF WORKING Mg ALLOY AND Mg ALLOY

Info

Publication number: WO2004085692A1
Application number: PCT/JP2004/001885
Authority: WO
Inventors: Taku Sakai
Original assignee: Campus Create Co., Ltd.
Priority date: 2003-03-26
Filing date: 2004-02-19
Publication date: 2004-10-07
Also published as: JPWO2004085692A1; JP4632949B2

Abstract

A process of working a Mg alloy, which has the steps of: (3-1) applying a strain in the X direction to the Mg alloy, while maintaining the temperature of the alloy at a temperature of 473 K or higher, and then lowering the temperature of the alloy; (3-2) applying a strain in the Y direction and then further lowering the temperature of the alloy; and (3-3) applying a strain in the Z direction. After the three steps, one or more of the above steps may be repeated. The process of working a Mg alloy allows the conversion of crystal grains of the Mg alloy to further fine grains, which leads to the production of a Mg alloy having improved formability.

Description

Processing method of Mg alloy and 合金_g alloy

The present invention relates to a method for processing a magnesium (Mg) alloy and a Mg alloy. Background

Mg alloys have the lowest density among practical metals and are therefore lightweight. In addition, Mg alloy is excellent in terms of Hiyumi Musume, ββ shearing properties, recyclability, etc.

However, Mg alloys have few slip systems in order to take the closest hexagonal lattice protection. For this reason, Mg alloys are low-growth and ||

In this specification, the term “Mg alloy” refers to an alloy having Mg as a maximum component and having a close-packed hexagonal structure, and includes neat Mg. The shape of the Mg alloy does not matter. Disclosure of the invention

The present invention has been made in view of the circumstances of liflB. An object of the present invention is to赚improvement of ¾ Ru processing method Oyohi Roe highly Mg alloy workability of M _g alloy.

The working of the Mg alloy according to the invention comprises the following steps:

(1) applying a strain in at least one direction to the ttilBMg alloy while keeping the Mg alloy to 473 K or more;

(2) Thereafter, a step of lowering the of of the tOfBMg alloy and applying a strain to the tiflBMg alloy in a direction different from one direction.

After step (2), the method may further include the following steps:

(3) A step in which the strain of the tiJfSMg alloy is further reduced, and strain is applied to the disfavorable BM g alloy in a direction different from the direction of the strain in the force and disgust steps (1) and (2).

The directions of the return distortion in the tfrt self-steps (1) to (3) may be substantially crossed with each other. After the ttflB step (1) to (3), the tiff self step (1) to (3) can be repeated or all steps can be repeated.

The true strain in Fujiji strain is preferably 0.3 or more L ヽ₉

It is preferable to apply strain in the next step within 3 minutes after applying ItitS strain L,

The value of the Mg alloy in the self-step (1) is preferably in the range of 500 K to 700 K.

The value of Mg alloy in the Fujimi step (2) is preferably within the range of 40 OK: up to 60 OK.

It is preferable that the temperature of the Mg alloy in the self-step (3) be in the range of 30 OK to 50 OK.

3¾ strain at Hall 2 strain that force s successful preferable in the range of ^{1 X 1 0- 3 ~ 1 X} 1 0 + 1 s one ^1.

The ΐίη½ strain is, for example, a la strain.

The Mg alloy according to the present invention has been processed by one of the following processes. The workpiece according to the present invention is obtained by processing a tiftSM g alloy.

The Mg alloy according to the present invention is an alloy having Mg as a maximum component and having a force and a P structure.

(1) applying a strain in at least one direction to the Mg alloy while maintaining the temperature of the Mg alloy at 473 K or more;

(2) Thereafter, a step of reducing the temperature of the disgusting Mg alloy and applying a force to the Mg alloy in a direction different from the t & | S- direction;

(3) further reducing the ¾g of the disgusting Mg alloy and applying a strain to the tilting Mg alloy in a direction different from the direction of the strain in the key steps (1) and (2);

The crystal grain size may be reduced to 1 μm or less by applying ΔT. The crystal grain size of the Mg alloy may be 0.2 m or less.

Further, the Mg alloy may have a Vickers hardness at room temperature of 100 OMPa or more, and a breaking elongation of 150% or more in a tensile test at 150 ° C. of 300% or more.

The Mg alloy according to the present invention is an alloy having a dense hexagonal structure with Mg as a maximum component, having a crystal grain size of 1 μm or less and a Vickers hardness at room temperature of 100 μm. OMPa or more and the elongation at break in a tensile test at 150 ° C. may be 300% or more.

The Mg alloy according to the present invention is an alloy having a fine hexagonal structure with Mg as a maximum component,

(1) adding strain in at least one direction to the knitted Mg alloy while maintaining the Kg of the Mg alloy at 473K or higher;

(2) Thereafter, the step of reducing the separation of the 3 Mg alloy and applying a strain to the lift self Mg alloy in a direction different from the 己-direction;

The crystal grain size is 1 μm or less, the hardness at room temperature is 100 OMPa or more, and the elongation at break in a tensile test at 150 ° C is 300% or more. A configuration may be used. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a block diagram showing an outline of an arrangement according to another embodiment of the present invention.

FIG. 2 is a diagram illustrating a Mg alloy to be added.

FIG. 3 is a flowchart for explaining a processing method according to one embodiment of the present invention. FIG. 4 is a graph showing actual results in an experimental example of the present invention. In this graph, the horizontal axis is cumulative strain and the vertical axis is (K).

FIG. 5 is a graph showing experimental results in an experimental example of the present invention. In this graph, the horizontal axis is the cumulative strain, and the vertical axis is the true stress.

FIG. 6 is a graph showing actual results in an experimental example of the present invention. In this graph, the abscissa indicates the cumulative strain (¾ "number display"), and the ordinate indicates the calo: force (constant state force) (logarithmic display). FIG. 7 is a graph showing actual results in an experimental example of the present invention. In this graph, the horizontal axis represents the crystal grain size D as D- ¹ . The vertical axis is the Vickers hardness at room temperature.

FIG. 8 is a graph showing actual i ^ results in an experimental example of the present invention. In this Dallaf, 1 $ is the nominal strain and the vertical axis is the true stress.

FIG. 9 is an optical micrograph of the Mg alloy obtained in the experiment of the present invention. Figure (a) is after the first stage (cumulative strain = 0.8), Figure (b) is after the second stage (cumulative strain = 1.6), and Figure (c) is after the fourth stage (cumulative strain). This is a photograph of a yarn fiber with a strain of 3.2). BEST MODE FOR CARRYING OUT THE INVENTION

According to one ^^ state of the present invention, the machining ^ removed by the M _g alloy, it will be described with reference to Xie drawings. First, the outline of the repair used in this process will be described. This apparatus includes a processing section 1, a heater 2, and a control section 3. The caroe part 1 is designed to be able to add strength to the Mg alloy A (see Fig. 2) from ± ^ directions. In this device, by changing (for example, rotating) the position of the Mg alloy A, it is possible to apply strains in three directions of the Mg alloy (X, M, Z directions on the Mg alloy). I have. The heater 2 heats the Mg alloy A to a predetermined temperature. The control unit 3 automatically or manually reduces the heating of the Mg alloy A by the heater when the processing direction (that is, the strain direction) of the working of the processing unit 1 on the Mg alloy A changes. Next, a method of processing the _Mg alloy in the present embodiment will be described.

(Step 3-1 in Figure 3)

First, the temperature of the Mg alloy body is increased to 473 K or more by heater 2. More preferably, the temperature of the Mg alloy is in the range of 500K to 70 OK. Note that if the temperature of the Mg alloy is sufficiently high in the inverted state, there is no need to heat the heater 2 with calorie. Next, iBf stress is applied to the Mg alloy in the X-axis direction in FIG. This strain is a compression strain in this embodiment. Strain, 1X10 one ³ within the range of ~ 1 X 10+ ¹ s one ^1, is more favorable Mashiku the range of ^{1 X 10- 2 ~1 X 10 +} 1 s- 1 is preferred. The true strain is 0.3 or more More preferably, the force is 0.4 or more. By setting the strain conditions within these ranges, it is expected that the crystal grains after processing will be favorably reduced.

(Step 3-2 in Figure 3)

Then, after releasing the image in the X-axis direction by the processing part 1, the content of the Mg alloy is reduced. However, the load stress may be released while fi¾ is decreasing. Here, the value of the Mg alloy is preferably in the range of 400K to 60OK. Next, strain is applied to the Mg alloy from the Y-axis direction (ie, a direction substantially perpendicular to the direction). The strain conditions are the same as in IB Step 3-1. After completing the strain processing in step 3-1, proceed to step 3-2! / The time until the strain is added is preferably within 3 minutes, more preferably within 2 minutes. The same applies to the subsequent steps.

(Step 3-3 in Figure 3)

Then, after releasing the image in the Y-axis direction, the hardness of the Mg alloy is further reduced. However, the load stress strain may be released during the temperature drop. Here, the S of the Mg alloy is preferably in the range of 30 OK to 500 °, and the force S is preferable. Then, with respect to the Mg alloy, the Z axis direction (that is, the X axis and

Therefore, strain is applied to the Mg alloy. The conditions of the distortion are the same as those of Step 3-1.

Then, after releasing the applied stress in the Z-axis direction, the temperature of the Mg alloy can be further lowered, and strain from the X or Y-axis direction can be applied to the Mg alloy.

According to this embodiment, the crystal grains grow with the increase in the number of processing steps. It is possible to obtain Mg alloy with high bow jewel and large elongation of the product.

In the present difficult embodiment, since the Mg alloy is strained from three directions, the crystal grain size can be further reduced. As a result, the deformation of the Mg alloy after processing

) Can be suppressed. However, if anisotropy can be tolerated, it is also possible to adopt a method of applying strain from only two directions. Also, a configuration may be adopted in which strains from four or more directions are applied to the Mg alloy. The age of the alloy must be reduced at each stage. Is considered necessary.

Also, the directions of the strain in each stage do not necessarily have to be orthogonal to each other. The point is that any direction may be used as long as it contributes to the refinement of the crystal grain size in the Mg alloy.

River test example)

The experiment was conducted under the following conditions in accordance with the cafeteria;

Cow)

Material: Mg alloy AZ31 (Mg alloy containing 3% by mass of A1, ⁰ % by mass of Zn)

Form of Mg alloy: Cut out from Maruyanagi bark

Shape of Mg alloy (specimen): Rectangular machine with height of 13mm, length of 12mm, width of 7mm (length direction is extrusion direction)

Strain boat ^{_{ε: 3 X 10- 3 S -}} 1 ( constant)

B crane strain at each stage: 0.8 (constant)

—At the stage (X car fat direction) strain] ϊβ ^ Τ: 673Κ

Floor (Υ axis direction) J¾ |? T at strain: 523K

Floor (Z-axis direction) Fiber separation under strain T: 473K

Fourth stage (X-axis direction) j¾ | UgT at strain: 433K

In other words, in this difficult form, after the return step 3-1, another strain was applied to the Mg alloy from the X-axis direction. Figure 4 shows the relationship between separation and cumulative strain. In this cat form, water ^ λ ^ Ι was applied at the end of each step, and the test piece was further polished and formed.Then, in the next step, 0.6 ~ 0.78 ks (Kiloseconds) After heating after separation, strain was applied to the test. The results are shown in FIGS. Figure 5 shows the relationship between cumulative strain and stress when strain is applied. At each stage, a large strain of Δ ε = 0.8 was obtained. Also, Τ = 4

Even at a low heating temperature of 73Κ or 433Κ, large strains can be obtained. The stress at this time becomes a considerably high force S does not fracture.赚 in FIG. 5 is a comparative example. Τ = 473

When processing is started at Κ, the stress rises sharply and breaks at a true strain of 0.3. Figure 6 shows the crystal grain size at the contact stage and the hiding of the stress at that time. The symbols (a) to (d) in the figure correspond to the first to fourth stages of leakage. Here, the crystal grain size is an average value of crystal grain sizes in a certain range in the yarn. The crystal grain sizes in the examples (a) to (d) are as follows.

^ a) 3.5 im

(b) 1.9 m

(c) 0.5 5 μΐ

(d) 0.1 8 μτη

In addition, 〇 in the figure shows data on the Mg alloy processed only from the uniaxial direction.

From these results, it can be seen that in this experimental example, the crystal grain size is much smaller than the conventional one. It can also be seen that the higher the stress, the smaller the crystal grain size.

FIG. 7 shows the H of the crystal grain size and the room temperature hardness. The right side of the horizontal axis in the figure indicates a smaller crystal grain size toward the right. According to this, it can be seen that the smaller the crystal, the higher the hardness, and the number of bows of the Mg alloy doubles due to the change in the yarn. For example, depending on the particle size, a Vickers hardness at room temperature of 100 OMPa can be obtained. As a result, we can see the power of improving the bow girl of the work using this alloy.

Figure 8 shows the results of ¾ "Ru pull test to M _g alloy has finished processing the four stages were膽己. In this test, the conditions of strain Kura ^{ε, 8. 3 X 10 ~ 3} s ~ \ 8. 3 X 10- ⁴ s one ^1, 8.3

X 10 — ⁵ s — ¹ In result, for example, 8. 3 X ¹ 0- ⁵ s- 1 strain Sg, 3

Nearly 00%, very high, and stretch could be obtained. ¾ ^ at this time is 423 K (that is, about

1 50 ° C). Also in fast strain boat that ^{^{8. 3 X 1 0- 3 s- 1}} , could be obtained Shinpi 100%禾. From these results, it can be seen that the Mg alloy obtained according to the present invention has characteristics that can be added. In other words, plastic working, which was conventionally difficult with Mg alloys, is now possible.

Figure 9 is a photograph of Crystal Paper. It turns out that it is fine crystal separation. It is to be noted that the description of the hate state is merely an example, and does not indicate a configuration essential to the present invention. Is not limited to the above as long as the gist of the present invention can be obtained.

Also, it is acceptable if the function blocks in the ti S¾EC device are combined into one function block. Also, the function of one function block may be performed in cooperation with a plurality of function blocks. Potential use of production

According to the present invention, it is possible to improve the workability of Mg alloy. In addition, a Mg alloy having high workability can be obtained.

Claims

The scope of the claims '

1. Machining Mg alloy with the following steps:-

(1) applying a strain in at least one direction to the t & fBMg alloy while keeping the temperature of the Mg alloy above 473K;

(2) After that, the step of lowering the tiftSMg alloy and applying a strain to the force and fiitBMg alloy in a direction different from the S-direction.

2. ΙίίΙΒ Step (2), after the step (2), the following steps are further performed:

(3) Step of further reducing the 3Mg alloy and applying a strain to the tiJtSMg alloy in a direction different from the direction of the strain in the lijf self-steps (1) and (2).

3. The processing method according to claim 2, wherein the direction of the self-distortion in the wisteria S step (1) to (3) is approximately 1 degree intersecting with each other.

4. The method according to claim 2 or 3, wherein after the self-editing steps (1) to (3), the step of repeating the all-or-nothing steps (1) to (3) or all steps are repeated. : Leave.

5. The processing according to claim 1 or 2, wherein the true strain amount in each knitting strain is 0.3 or more.

6. Applying the strain in the next step within 3 minutes after applying the strain, processing according to any one of claims 1 to 5, or removing.

7. The processing according to any one of claims 6 to 6, wherein the temperature of the Mg alloy in the step (1) is within a range of 500K to 700K.

8. The process according to claim 1, wherein the temperature of the Mg alloy in the step (2) is in the range of 400K to 600K, and the processing is performed according to any one of claims 1 to 7.

9. The processing method according to any one of claims 2 to 8, wherein the Mg alloy in the step (3) is in a range of 300 to 500K.

10. This said strain rate in each strain is in the range of ^{^{1X 10- 3 ~ 1 X 10+ 1}} s 1 The process according to any one of claims 1 to 9, wherein

1 1. The circuit strain shall be abrupt. Claims 1 to 1: Any one of L 0 1 Machining with fE.

1 2. Mg alloy processed by the processing method described in claims 1 to 11

13. A caroe obtained by processing the Mg alloy according to claim 12.

1 4. An alloy that has a maximum composition of Mg and has a sperm structure.

(1) A step of applying strain to the ffjfB Mg alloy in at least one direction;

(2) Thereafter, the step of reducing the temperature of the tGlBMg alloy and applying a strain to the Mg alloy in a direction different from the Fujimi direction;

(3) further reducing the ¾g of the 1515 Mg alloy, and applying a strain to the Sukki alloy in a direction different from that of the strain in the Sukki steps (1) and (2);

As a result, it is determined that the crystal diameter is 1 μm or less.

15. The Mg alloy according to claim 14, wherein the crystal grain size is 0.2 μm or less.

16. Further, the Vickers hardness at room temperature should be 100 MPa or more, and the elongation at break in a tensile test at 150 ° C. should be 300% or more. 4 Mg total

1 7. Fine 6 ^ with Mg as the largest component? An alloy having a structure, its crystal; ¾ not more than 1 m, Vickers hardness at room temperature not less than 100 OMPa, and breaking elongation in a tensile test at 150 ° C. M g total ^ _{0 where}敷 is set to 3 0% or more as f

1 8. An alloy that has a string structure with Mg as the largest component.

(1) straining the ItjfE Mg alloy in at least one direction while maintaining the Mg alloy key at 473K or higher;

(2) Afterwards, reducing the させ g of the g alloy and applying a strain to the force and the unfavorable SMg alloy in a direction different from the direction of the hall; By ^

The crystal grain size is 1 βm or less, and the Vickers hardness at room temperature is 100 OMPa or more. It is assumed that the elongation at break in the test in C is 300% or more.