JP2009091624A - Aluminum-based material and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aluminum-based material which has high strength, high hardness and superior forgeability, and to provide a manufacturing method therefor. <P>SOLUTION: The aluminum-based material contains crystal grains of an aluminum alloy, and includes (1) fine particles of a scandium compound, and (2) the crystal grains having grain sizes of 5 μm or less in an amount of 100 pieces or more per 1,000 μm<SP>2</SP>of the aluminum-based material. The manufacturing method is also disclosed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a novel aluminum-based material and a method for producing the same.

  In aircraft materials, automobile parts materials, precision machine parts materials, electronic materials, spring materials, screw materials, etc., high-strength aluminum alloy moldings are widely used because of the demand for weight reduction. However, in terms of strength, it is not yet sufficient as compared with steel materials, and various high-strength alloys have been studied.

  By the way, generally, a metal material such as an aluminum alloy has a polycrystalline structure in which a large number of crystal grains are arranged. In the relationship between the crystal grain size and the strength of the metal-based material (Hall-Petch equation), it has been found that the crystal grain size and the strength are inversely related. That is, it has been found that the smaller the crystal grains, the higher the strength of the metal material. Therefore, in order to obtain high strength, it is important to refine crystal grains constituting the metal material.

  As a method for refining the crystal grains, there has been proposed a method (TMT method) in which a metal material such as an aluminum alloy is extruded and processed into a molded body, and then the molded body is heated (non-patent document). 1).

  However, this TMT method can make the crystal grains finer, but particularly in an aluminum alloy, the size of the crystal grains can be reduced only to about 10 μm at most. And there is room for improving hardness.

On the other hand, since an aluminum alloy is used for various materials as described above, it is also formed into a material having a complicated structure. Therefore, in addition to high strength and the like, it is also important that it can be easily molded. In other words, a property (forgeability) that is high strength during use but can be easily deformed during processing (high temperature) is also required.
Yotaro Murakami: Bulletin of the Japan Institute of Metals, Vol. 13 (1974), p479.

  It is an object of the present invention to provide an aluminum-based material having a further excellent strength and hardness and having good forgeability and a method for producing the same.

  In view of the above prior art, the present inventors have made extensive studies. As a result, it has been found that by using a specific raw material and further performing a specific process, an aluminum-based material having further excellent strength and the like and having good forgeability can be produced. The present invention has been completed based on such findings. That is, this invention relates to the following aluminum-type material, its forged product, and those manufacturing methods.

Item 1. An aluminum-based material containing crystal grains of an aluminum alloy,
(1) The aluminum-based material contains scandium compound fine particles,
(2) There are 100 or more crystal grains having a grain size of 5 μm or less per 1000 μm ^{2 of the} aluminum-based material.
An aluminum-based material characterized by that.

  Item 2. Aluminum type material is Al 83.5-90 mass%, Zn 7-10 mass%, Mg 2-4.5 mass%, Cu 0.5-2 mass%, Ag 0.01-0.1 mass%, and Sc0.2-2. Item 2. The aluminum-based material according to Item 1, comprising mass%.

  Item 3. Item 3. The aluminum-based material according to Item 1 or 2, wherein the scandium compound fine particles have an average particle size of 3 nm to 50 nm.

Item 4. Item 4. The aluminum-based material according to any one of Items 1 to ₃ , wherein the scandium compound fine particles are Al ₃ Sc.

  Item 5. Item 5. The aluminum-based material according to any one of Items 1 to 4, wherein the content of the scandium compound fine particles is 1 to 5% by volume.

  Item 6. Item 6. A forged product made of an aluminum-based material, obtained by forging the aluminum-based material according to any one of items 1 to 5.

Item 7. Item 7. The forged product according to Item 6, wherein there are 200 or more crystal grains having a particle size of 5 µm or less per 1000 µm ^{2 of the} aluminum material.

Item 8. A method for producing an aluminum-based material, comprising:
(1) a first step of preparing rapidly solidified powder from a molten metal containing aluminum and scandium by an atomizing method;
(2) a second step of producing a molded body by molding the powder;
(3) including a third step of depositing scandium compound fine particles in the compact by heating the compact, and (4) a fourth step of obtaining an extruded material by hot extruding the compact. A method for producing an aluminum-based material.

  Item 9. Molten metal is Al 78.5-90.29 mass%, Zn 7-12 mass%, Mg 2-5 mass%, Cu 0.5-2 mass%, Ag 0.01-0.1 mass%, and Sc 0.2-2 mass%. The manufacturing method of claim | item 8 containing this.

  Item 10. Item 10. The method according to Item 8 or 9, wherein in the third step, heating is performed at a temperature rising rate of 10 to 100 ° C / min.

  Item 11. Item 11. The production method according to any one of Items 8 to 10, wherein the scandium compound fine particles have an average particle size of 3 nm to 50 nm.

Item 12. 5th process which further forges the aluminum-type material obtained by the manufacturing method in any one of claim | item 8 -11.
Forging products including

1. Aluminum-based material The aluminum-based material of the present invention is an aluminum-based material containing crystal grains of an aluminum alloy, and (1) the aluminum-based material contains scandium compound fine particles, and (2) the particle size is 5 μm or less. More than 100 crystal grains exist per 1000 μm ² of the aluminum-based material. This will be described in detail below.

  The aluminum-based material of the present invention is a material containing aluminum alloy and scandium compound fine particles, and has a polycrystalline structure composed of crystal grains of a plurality of aluminum alloys. Scandium compound fine particles are contained in the crystal grain boundaries.

  Although the crystal grain of an aluminum alloy is not limited, it should just contain aluminum about 80 mass% or more, and should just contain Zn, Mg, Cu, Ag, Si, etc. as other metal seeds. . Specific examples of the preferable composition of the aluminum alloy of the present invention include, for example, Al 81 to 94% by mass, Zn 4 to 10% by mass, Mg 1 to 4% by mass, Cu 0.5 to 2% by mass, and Ag 0 to 0.2% by mass. It is. Particularly preferable are Al 82 to 90% by mass, Zn 7 to 10% by mass, Mg 2 to 4% by mass, Cu 0.5 to 2% by mass, and Ag 0.01 to 0.1% by mass.

In the present invention, it is essential that 100 or more crystal grains having a grain size of 5 μm or less are present per 1000 μm ^{2 of the} aluminum-based material. Preferably 200 or more, most preferably 300 or more. As described above, since there are a large number of crystal grains having a very small grain size, the aluminum-based material of the present invention has extremely high strength such as yield strength and tensile strength, and excellent forgeability. The upper limit of the number present is not limited, but is usually about 800 or less. Moreover, although the minimum of the particle size of the crystal grain of 5 micrometers or less is not limited, For example, what is necessary is just to be about 1 micrometer.

  The crystal grain size and the number of crystal grains in the present invention are measured using SEM-EBSD (scanning electron microscope-electron beam backscatter diffraction method).

  The aluminum-based material of the present invention further contains fine particles of a scandium (Sc) compound in addition to the aluminum alloy crystal grains. Thus, by including scandium compound fine particles, forgeability and the like are excellent. In addition, the crystal grains can be further refined during forging, and the aluminum-based material (forged product) after forging can have higher strength and higher hardness.

  The composition of the aluminum-based material of the present invention is Al 83.5 to 90% by mass, Zn 7 to 10% by mass, Mg 2 to 4.5% by mass, Cu 0.5 to 2% by mass, Ag 0.01 to 0.1% by mass, and It is preferable that it consists of Sc0.2-2 mass%. More preferably, they are Al84-90 mass%, Zn7-10 mass%, Mg2-4 mass%, Cu0.5-2 mass%, Ag0.01-0.1 mass%, and Sc0.2-2 mass%.

As the scandium compound fine particles, for example, a scandium-aluminum compound, particularly, Al ₃ Sc is preferably exemplified. The average particle diameter of the fine particles is not limited, but is usually about 3 nm to 50 nm, preferably about 5 nm to 20 nm. By setting it as this range, the pinning force by the fine particles can be increased, and the crystal grains of the aluminum alloy can be increased. As a result, strength, hardness, etc. can be improved.

  The content of the scandium compound fine particles is not limited, but may be, for example, about 1 to 5% by volume, preferably about 2 to 4% by volume in the aluminum-based material.

In the present invention, fine particles of other inorganic compounds may be included. For example, fine particles such as a zirconium compound and a scandium-zirconium composite compound may be included. More specifically, Al ₃ Zr, Al ₃ (Zr, Sc) and the like can be mentioned. The average particle size of these fine particles is not limited, but is usually about 3 nm to 50 nm, preferably about 5 nm to 20 nm.

  When zirconium compound fine particles are contained, the content thereof may be about 0.01 to 3% by volume, preferably about 0.5 to 2% by volume in the aluminum-based material.

  The scandium compound fine particles and the inorganic compound fine particles are preferably present in a dispersed state in the crystal grains constituting the aluminum alloy and / or in the crystal grain boundaries.

  The measurement method of the average particle diameter of these scandium compound fine particles and inorganic compound fine particles is performed by a method of calculating an average value by selecting about 100 arbitrary particles by image analysis by cross-sectional electron microscope observation (for example, TEM). .

  The content (volume%) of the scandium compound fine particles and the inorganic compound fine particles is measured from a phase diagram (aluminum = scandium binary phase diagram, etc.).

  Since the aluminum-based material of the present invention has the above characteristics, it has excellent strength, hardness, and the like. In addition, the aluminum-based material of the present invention is excellent in forgeability, that is, has a low high-temperature deformation resistance, and thus can be easily deformed by heating. Specifically, it has excellent strength as described above at room temperature, but when heated to a high temperature, deformation is processed at a lower compression pressure. Therefore, it becomes easy to process parts having a more complicated structure.

  In addition, the forged aluminum-based material (aluminum-based material forged product) is further refined in crystal grains by a forging process, and has more excellent strength, hardness, and the like.

2. Method for Producing Aluminum-Based Material A method for producing an aluminum-based material according to the present invention includes (1) a first step of preparing a rapidly solidified powder from a molten metal containing aluminum and scandium by an atomizing method, and (2) by forming the powder. A second step of producing a molded body, (3) a third step of depositing scandium compound fine particles in the molded body by heating the molded body, and (4) extrusion by hot extruding the molded body. A fourth step of obtaining a material.

(1) First Step In the first step, a rapidly solidified powder is prepared from a molten metal containing aluminum and scandium by an atomizing method.

  The molten metal used in the present invention is not limited as long as it contains aluminum and scandium. For example, it is sufficient that aluminum is contained in an amount of about 80% by mass or more, and as other metal species, Zn, Mg, Cu , Ag, Si and the like may be contained. For example, Al 78.5-90.29 mass%, Zn 7-12 mass%, Mg 2-5 mass%, Cu 0.5-2 mass%, Ag 0.01-0.1 mass%, and Sc 0.2-2 mass% ( In particular, Al 84 to 90% by mass, Zn 7 to 10% by mass, Mg 2 to 4.5% by mass, Cu 0.5 to 2% by mass, Ag 0.01 to 0.1% by mass, and Sc 0.2 to 2% by mass). Molten metal is preferred. The molten metal may further contain about 0.15 to 1.5% by mass of Zr.

  The material of the molten metal is, for example, an alloy material generally used in 2000 series, 6000 series, 7000 series alloys, etc. and known or commercially available scandium, etc., which are mixed in an appropriate amount, and the composition ratio of the molten metal What is necessary is just to prepare so that. In the present invention, scandium or a compound thereof is added to the 7000 series alloy material (Al—Zn—Mg—Cu series alloy material, in particular, Al—Zn—Mg—Cu—Ag series alloy material) in the above blending ratio (0.2 to 0.2). 2% by mass) is preferably mixed. When the ratio of scandium exceeds 2% by mass, it becomes difficult to dissolve in the treatment by the atomizing method, and coarse scandium compound fine particles may be precipitated. On the other hand, if it is less than 0.2% by mass, the effect of increasing crystal grains may not be exhibited.

  For the preparation of the molten metal, for example, an Al alloy raw material having the above composition may be melted in a high-frequency melting furnace and held at a temperature of about 800 to 1000 ° C.

  The atomizing method may be any of a gas atomizing method, a water atomizing method, a centrifugal atomizing method, and the like, for example, but in the present invention, the gas atomizing method can be suitably used. As a gas (fluid) used in the gas atomization method, for example, in addition to air, an inert gas (argon, helium, nitrogen, etc.) can be used.

Atomization can be performed using a known apparatus (gas atomizer). For example, Al alloy molten metal is poured into a crucible attached to an atomizer. A hole is made in the bottom of the crucible so that it can be led from here to the molten metal outlet of the atomizing nozzle without lowering the temperature of the molten metal. Immediately before the Al alloy molten metal reaches the atomized nozzle molten metal outlet, high pressure air atomized gas is ejected from the nozzle hole, and the Al alloy molten metal coming out of the molten metal outlet is finely pulverized by the pressure of this gas. . The molten metal finely pulverized in this manner is immediately cooled and solidified by a high-pressure gas and / or atmosphere to obtain an Al alloy rapidly solidified powder. In atomization, the molten Al alloy is solidified at a cooling rate of 10 ² K / second or more.

  The Al alloy rapidly solidified powder obtained by the atomization method can be sieved to a predetermined particle size (for example, 150 μm or less by a 100-mesh sieve) depending on the application. Further, the particle shape of the Al alloy rapidly solidified powder is not limited, and may be any of spherical shape, flake shape, and indefinite shape.

(2) 2nd process In a 2nd process, a molded object is produced by shape | molding the said powder. The molding method is not particularly limited, and a known method such as cold isostatic pressing (CIP) or hot isostatic pressing (HIP) can be employed. The molding pressure at the time of molding can be appropriately determined according to the desired relative density, the composition of the powder to be used, and the like, but it is usually about 500 to 5000 kg / cm ² . Alternatively, after the Al alloy powder rapidly solidified powder obtained as described above is solidified and formed, degassing treatment may be performed if necessary.

(3) Third Step In the third step, scandium compound fine particles are precipitated in the molded body by heating the molded body.

The heating temperature is about 400 to 550 ° C, preferably about 450 to 500 ° C. By setting this temperature, scandium compound fine particles (especially Al ₃ Sc) can be precipitated in the formed body (for example, in the crystal grains and / or crystal grain boundaries of the aluminum alloy).

In the present invention, the heating rate is preferably about 10 to 100 ° C./min, particularly about 15 to 30 ° C./min during the heating. When the molded body is heated to a temperature in the above range, scandium compound fine particles are precipitated, and the precipitated fine particles depend on the rate of temperature rise. For example, if the rate of temperature rise is too fast, the particle size of the fine particles that precipitate out increases. On the other hand, if the rate of temperature rise is too slow, the particle size becomes small. Here, in the fourth step, which will be described later, the precipitated fine particles will refine the crystal grains. However, if the precipitated fine particles are too large, the crystal grains due to the fine particles produced in the fourth step are refined. The force to be applied (pinning force) becomes too small, and there is a possibility that miniaturization cannot be performed. Moreover, even if it is too small, there is a possibility that the pinning force becomes too small and cannot be miniaturized. Therefore, by setting the heating rate within the above range, it becomes possible to precipitate scandium compound fine particles having a particle size (for example, about 3 nm to 50 nm, particularly about 5 nm to 20 nm, which is more suitable for miniaturization. In addition, it is possible to easily manufacture an aluminum material to be manufactured in which 100 or more crystal grains exist per 1000 μm ² .

  The holding time after the temperature rise is not limited, but is usually 0.5 to 5 hours, preferably 0.5 to 1 hour.

  The heat treatment atmosphere in this case is generally performed in an air atmosphere, but may be heated in an inert atmosphere.

(4) Fourth Step In the fourth step, an extruded material is obtained by hot extruding the molded body. That is, extrusion is performed while maintaining the heated state in the third step. Although the alloy crystal is refined during the extrusion, the crystal grain is remarkably refined by the synergistic effect of the presence of the scandium compound fine particles precipitated in the third step and the pressure applied to the compact. It will be.

  What is necessary is just to perform the temperature conditions in the case of hot extrusion at the heating temperature performed at the 3rd process, and are about 350-550 degreeC normally, Preferably what is necessary is just about 450-500 degreeC. The conditions for hot extrusion are not limited. The extrusion ratio can be a molding material by extruding at about 5 to 100 (particularly about 10 to 60).

  The extrusion speed is not limited, but is usually about 10 to 300 mm / min, preferably 30 to 100 mm / min.

  The pressure applied to the molded body at the time of extrusion may usually be about 400 MPa to 2000 MPa.

(5) 5th process In this invention, you may perform this 5th process further after a 4th process as needed. In the fifth step, an aluminum material forged product is obtained by forging the extruded material.

  Forging may be performed, for example, by compressing at a high temperature.

  The temperature during forging is usually about 350 to 550 ° C, preferably about 400 to 480 ° C.

  The pressure at the time of compression is not particularly limited as long as the aluminum-based material can be compressed at the above temperature, but is usually about 1 MPa to 30 MPa, preferably about 1 MPa to 20 MPa.

  Further, if necessary, after the fifth step (after the fourth step when the fifth step is not performed), the forged product obtained in the fifth step or the extruded material obtained in the fourth step is 400 to 400. After the volumeification treatment at 550 ° C. (preferably 450 to 500 ° C.), it can be rapidly cooled in ice water and further subjected to T6 treatment. In the T6 treatment, for example, after heating at 450 to 500 ° C. for 0.5 to 2 hours, it may be further heated at 100 to 130 ° C. for about 20 to 100 hours.

  According to the present invention, since it includes specific fine particles and further has a specific fine crystal structure, it is possible to provide an aluminum-based material having superior strength, hardness, and forgeability, and a forged product thereof. .

  According to the manufacturing method of the present invention, since a specific material is used as a raw material and further molded at a high temperature, an aluminum-based material including specific fine particles and having a fine crystal structure and a forged product thereof are manufactured. be able to.

  The aluminum-based material and the forged product of the present invention can be suitably used as, for example, aircraft materials, automobile component materials, precision machine component materials, electronic materials, spring materials, screw materials, and the like. In particular, it is also optimal as a material for automobile parts and the like that are highly demanded for weight reduction and precision.

  The features of the present invention will be described more specifically with reference to the following examples and comparative examples. However, the scope of the present invention is not limited to the examples.

Aluminum (Al) -based materials were prepared using aluminum (Al) alloy raw materials having the following compositions. In the following composition, the Al composition ratio (mass%) is the remainder of the other alloy components.
-Composition No. 1: Al-9.59Zn-3.11Mg-1.47Cu-0.04Ag-1.43Sc (mass%)
-Composition No. 2: Al-9.60Zn-3.09Mg-1.45Cu-0.04Ag-0.74Sc (mass%)
-Composition No. 3: Al-9.50Zn-3.15Mg-1.42Cu-0.04Ag-0.37Sc (mass%)
-Composition No. 4: Al-8.76Zn-2.93Mg-1.62Cu-0.04Ag (mass%)
Example 1
(First step)
Said composition No. The Al alloy raw material having the composition of 1 is melted in a high-frequency melting furnace and maintained at a temperature of 900 ° C., and then the Al alloy molten metal is poured into a crucible attached to an atomizer, and Al alloy rapidly solidified powder (average particle diameter) is obtained by a gas atomization method. Was 40 μm). The particle size was measured by a laser diffraction particle size distribution measurement method.

(Second step)
The obtained powder is filled into a rubber mold, and a powder green compact with a diameter of 95 mm × length of 200 mm is produced at a molding surface pressure of 1500 kg / cm ² by cold isostatic pressing (CIP). Billet for use.

(Third step)
Next, the billet was heated to 500 ° C. at a temperature rising rate of 40 ° C./min. Thereby, scandium compound fine particles (Al ₃ Sc) were precipitated in the Al alloy. The average particle size of the precipitated fine particles was measured and found to be 31 nm. The average particle size was measured by TEM.

(4th process)
After maintaining the billet at 500 ° C. for 1 hour, hot extrusion was performed at an extrusion ratio of 10 and an extrusion speed of 30 mm / min to produce a rod-shaped extruded material (Al-based material) of Example 1 having a diameter of 10 mm. A test piece was prepared from the extruded material.

The obtained Al-based material of Example 1 was measured by SEM / EBSD, and crystal grains constituting the Al-based material were measured. The measurement results are shown in FIG. In addition, when crystal grains having a grain size of 5 μm or less were calculated from FIG. 1, there were 385 grains per 1000 μm ² . The content of Al ₃ Sc fine particles in the Al-based material was 3.9% by volume. This content (volume%) was calculated from a phase diagram (aluminum = scandium binary phase diagram) at 500 ° C., which is the heating temperature of the billet.

  The tensile strength, yield strength, and hardness of the Al-based material of Example 1 were measured. These results are shown in Table 1. The tensile strength and yield strength were obtained by cutting the extruded material (Al-based material) of Example 1 into a cylindrical test piece having a diameter of 2.4 mm and a length of 15.9 mm, and performing T6 treatment on the test piece. Using a tensile tester (manufactured by Shimadzu Corp., Autograph AG-IS), the tensile test was performed by performing a tensile test at an initial strain rate of 2% / min. The hardness was determined by cutting the extruded material (Al-based material) of Example 1 into a cylindrical test piece having a diameter of 10 mm and a length of 10 mm, and subjecting the test piece to T6 treatment. -E) was used to measure the Vickers hardness with a load of 300 gf. In this example, the T6 treatment was performed by heating the test piece at 490 ° C. for 30 minutes and further heating at 110 ° C. for 30 hours.

  Further, in order to evaluate forgeability, the high temperature deformation resistance of the Al-based material of Example 1 was measured. The results are shown in Table 1. The high temperature deformation resistance was obtained by cutting the extruded material (Al material) of Example 1 into a cylindrical test piece having a diameter of 10 mm and a length of 15 mm, and then using a hydraulic servo type material strength tester (manufactured by Shimadzu Corporation, EHF-ED5). This test piece was measured by compressing the test piece under the conditions of 440 ° C. and initial strain rate of 120% / min, and measuring the compression resistance.

Example 2
The Al alloy raw material is composed of the composition No. An Al-based material of Example 2 was produced in the same manner as Example 1 except that the composition of 2 was used.

The average particle size of the Al ₃ Sc fine particles precipitated in the third step was 33 nm. The content was 2.1% by volume. In addition, when the crystal grains having a particle size of 5 μm or less of the obtained Al-based material of the example were measured, there were 159 particles per 1000 μm ² .

  Table 1 shows the measurement results of the tensile strength, hardness, and yield strength of the Al-based material of Example 2.

Example 3
The Al alloy raw material is composed of the composition No. An Al-based material of Example 3 was produced in the same manner as in Example 1 except that the composition was 3.

The average particle diameter of the Al ₃ Sc fine particles precipitated in the third step was 22 nm. The content was 1.0% by volume. The measured crystal grain particle size 5μm or less of Al-based material obtained in Examples, 1000 .mu.m ² per were present 125.

  Table 1 shows the measurement results of tensile strength, yield strength, hardness, and high temperature deformation resistance of the Al-based material of Example 3.

Example 4
An Al-based material of Example 4 was produced in the same manner as in Example 1 except that the temperature increase rate in the third step was 15 ° C./min.

The average particle size of the Al ₃ Sc fine particles precipitated in the third step was 5.1 nm. The content was 3.9% by volume. The measured crystal grain particle size 5μm or less of Al-based material obtained in Examples, 1000 .mu.m ² per 433 cells was present.

  Table 1 shows the measurement results of tensile strength, yield strength, hardness, and high temperature deformation resistance of the Al-based material of Example 4.

Example 5
The Al alloy raw material is composed of the composition No. The Al-based material of Example 5 was manufactured in the same manner as in Example 1 except that the composition was 2 and the temperature increase rate in the third step was 15 ° C./min.

The average particle size of the Al ₃ Sc fine particles precipitated in the third step was 7.8 nm. The content was 2.1% by volume. Further, when crystal grains having a particle size of 5 μm or less of the Al-based material of the obtained example were measured, there were 223 particles per 1000 μm ² .

  Table 1 shows the measurement results of tensile strength, yield strength, hardness and high temperature deformation resistance of the Al-based material of Example 5.

Comparative Example 1
The Al alloy raw material is composed of the composition No. An Al-based material of Comparative Example 1 was produced in the same manner as in Example 1 except that the composition of 4 was used.

The crystal grains of the obtained Al-based material of Comparative Example 1 were measured. The measurement results are shown in FIG. In addition, when crystal grains having a grain size of 5 μm or less were calculated from FIG. 2, there were 29 grains per 1000 μm ² .

  Table 1 shows the measurement results of tensile strength, yield strength, hardness, and high temperature deformation resistance of the Al-based material of Comparative Example 1.

  The average particle diameters of the Al alloy rapidly solidified powders obtained in the first step of Examples 2 to 5 and Comparative Example 1 were both in the range of 35 to 50 μm.

Example 6
(5th process)
The Al-based material forged product of Example 6 was manufactured by high-temperature compression (compression pressure: 10 MPa) of the Al-based material obtained in Example 1 at an initial strain rate of 120% / min and 440 ° C.

The crystal grains constituting this forged product were measured. The measurement results are shown in FIG. When crystal grains having a grain size of 5 μm or less were calculated from FIG. 3, there were 523 crystals per 1000 μm ² .

  Moreover, the hardness of the forged product of Example 6 was measured. The results are shown in Table 2.

Examples 7 to 8 and Comparative Example 2
The fifth step was carried out on the Al-based materials obtained in Examples 2-3 and Comparative Example 1 in the same manner as in Example 6 to produce Al-based material forged products of Examples 7-8 and Comparative Example 2, respectively.

When the crystal grains constituting these forged products were measured, the number of crystal grains per 1000 μm ² was 410 in Example 7, 248 in Example 8, and 62 in Comparative Example 2. In addition, the measurement result of the forged product of the comparative example 2 is shown in FIG.

  Further, the hardness of the forged products of Examples 7 to 8 and Comparative Example 2 was measured. The results are shown in Table 2.

Evaluation As compared with the Al-based material of Comparative Example 1, the Al-based materials of Examples 1 to 5 of the present invention showed good values for both yield strength and tensile strength. Moreover, since the value of high temperature change resistance was low, it was excellent in forgeability.

  Furthermore, even when compared with the Al-based material forged product of Examples 6 to 8 of the present invention as compared with the Al-based material forged product of Comparative Example 2, the values of hardness and the like were high and good.

FIG. 1 shows the crystal grain state of the Al-based material of Example 1 measured by SEM / EBSD. FIG. 2 shows the crystal grain state of the Al-based material of Comparative Example 1 measured by SEM / EBSD. FIG. 3 shows the crystal grain state of the Al-based material forged product of Example 6 measured by SEM / EBSD. FIG. 4 shows the crystal grain state of the Al-based material forged product of Comparative Example 2 measured by SEM / EBSD.

Claims (12)

An aluminum-based material containing crystal grains of an aluminum alloy,
(1) The aluminum-based material contains scandium compound fine particles,
(2) There are 100 or more crystal grains having a grain size of 5 μm or less per 1000 μm ^{2 of the} aluminum-based material.
An aluminum-based material characterized by that.   Aluminum type material is Al 83.5-90 mass%, Zn 7-10 mass%, Mg 2-4.5 mass%, Cu 0.5-2 mass%, Ag 0.01-0.1 mass%, and Sc0.2-2. The aluminum-based material according to claim 1, comprising mass%.   The aluminum-based material according to claim 1 or 2, wherein the scandium compound fine particles have an average particle diameter of 3 nm to 50 nm. The aluminum-based material according to claim 1, wherein the scandium compound fine particles are Al ₃ Sc.   The aluminum-based material according to any one of claims 1 to 4, wherein the content of the scandium compound fine particles is 1 to 5% by volume.   A forged product made of an aluminum-based material obtained by forging the aluminum-based material according to claim 1. The forged product according to claim 6, wherein there are 200 or more crystal grains having a particle size of 5 µm or less per 1000 µm ^{2 of the} aluminum-based material. A method for producing an aluminum-based material, comprising:
(1) a first step of preparing rapidly solidified powder from a molten metal containing aluminum and scandium by an atomizing method;
(2) a second step of producing a molded body by molding the powder;
(3) including a third step of depositing scandium compound fine particles in the compact by heating the compact, and (4) a fourth step of obtaining an extruded material by hot extruding the compact. A method for producing an aluminum-based material.   Molten metal is Al 78.5-90.29 mass%, Zn 7-12 mass%, Mg 2-5 mass%, Cu 0.5-2 mass%, Ag 0.01-0.1 mass%, and Sc 0.2-2 mass%. The manufacturing method of Claim 8 containing these.   The manufacturing method of Claim 8 or 9 which heats at a temperature increase rate of 10-100 degrees C / min in a 3rd process.   The manufacturing method in any one of Claims 8-10 whose average particle diameter of a scandium compound fine particle is 3 nm-50 nm. 5th process which further forges the aluminum-type material obtained by the manufacturing method in any one of Claims 8-11,
Forging products including

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