JP2003064406A - Parts made of aluminum alloy and production method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the overspecks of parts produced by using rapidly solidifying aluminum alloy powder obtained by an atomizing method as a starting raw material, and to reduce useless working. SOLUTION: A preliminary compact 1 obtained by compacting the atomizing powder of an Al alloy containing 10 to 40 mass% Si as the raw material is heated to a temperature in a prescribed range. Next, plastic deformation is applied only to the part requiring mechanical strength therein by an amount required for the appearance of the characteristics, and the densification of the alloy and the impartation of the shape of parts are simultaneously performed. The part with the required plastic deformation applied is provided with a structure in which the mean value of the aspect ratios of the alloy powder grains is >=3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention eliminates wasteful steps for avoiding excessive specifications of aluminum alloy parts manufactured by powder metallurgy, which have excellent strength, heat resistance and creep resistance. And a manufacturing method for manufacturing the same.

[0002]

2. Description of the Related Art Aluminum alloy parts manufactured by pressing and forging using a rapidly solidified aluminum alloy powder obtained by an atomizing method as a starting material include, for example,
JP 2001-98304 A describes a piston for internal combustion engine, a cylinder sleeve, a connecting rod, a valve lifter,
There are various things such as rocker arms and scroll plates for compressors.

An oxide film is present on the surface of the rapidly solidified aluminum alloy powder produced by atomization. Therefore, when the powder is used as a raw material for making parts, the strength and toughness required for the parts are ensured. In addition, it is necessary to destroy the oxide film on the surface and promote the bonding of the powder.

As a technique therefor, the above-mentioned Japanese Patent Laid-Open No. 2001
-98304 is a raw material which is compacted into a metal lump, which is then pressed hot to densify the structure, and then upset to produce an aluminum alloy billet for forging. To manufacture forged pistons for internal combustion engines.

[0005]

In the prior art disclosed in the above publications, the compacted powder compact is once densified, and the material in the entire region is plastically deformed by upsetting. However, the plastic deformation is required to break the oxide film on the surface of the raw material powder to strengthen the material, such as the ceiling of the piston where the load is high, whereas according to the conventional method, a large mechanical strength is required. There is a high possibility that large plastic flow will occur even in the parts that do not require, and the material properties will be over-specified.

The overspec of its material properties increases unnecessary processing. However, it is not known which part of the component should be finally added with the amount of plastic deformation, and thus it is impossible to prevent over-spec which increases unnecessary machining.

The present invention has been made in view of the above points, and an object thereof is to provide an aluminum alloy part in which over-spec is eliminated by using the cross-sectional structure of the part as an index and a method for manufacturing the part. There is.

[0008]

In order to solve the above-mentioned problems, in the present invention, the amount of plastic deformation required for exhibiting the characteristics is given only to the portion requiring mechanical strength in the process of densifying the structure. The average value of the aspect ratio of the aluminum alloy powder particles observed in the plane in which the internal structure of the site is parallel to the direction requiring mechanical strength is the major axis length of the powder particles is a, and the minor axis length is b. As a result, an aluminum alloy part having a structure represented by a / b ≧ 3 is provided.

As a starting material, Si: 10-40
Mass%, 3 to 11 mass% of one or more elements selected from V, Cr, Mn, Fe, Co and Ni, Ti:
Parts using a rapidly solidified aluminum alloy powder having a composition of 1 to 3 mass% and the balance substantially consisting of Al, and Si: 10
~ 30 mass%, Ti, V, Cr, Mn, Fe, Co, N
One or more elements selected from i, Mo and W are 3 to 10% by mass in total, Zr: 1 to 3% by mass, rare earth elements (including misch metal): 3 to 6% by mass, and the balance is substantially And a part using a rapidly solidified aluminum alloy powder having a composition of Al.

Further, regarding the starting material having the specified composition, a step of atomizing the molten metal to obtain a rapidly solidified aluminum alloy powder having a desired composition, the rapidly solidified aluminum alloy powder being cold compacted and preliminarily prepared The step of obtaining a compact, the step of heating the preform to a temperature of 430 ° C. or higher and 530 ° C. or lower, the heated preform is immediately subjected to hot plastic working, and the relative density of necessary parts is 99% or higher. In addition to manufacturing the aluminum alloy parts through the steps of performing part shape imparting and the above steps, in the densification and part shape imparting steps, it is necessary to develop characteristics only in the parts that require mechanical strength of the parts. The average value of the aspect ratio of the aluminum alloy powder particles after solidification observed in a plane parallel to the direction in which the maximum stress is applied, given the amount of plastic deformation. , Powder particle major axis length a, short axis as b, providing together a method of manufacturing an aluminum alloy part, wherein the obtaining tissue represented by a / b ≧ 3.

[0011]

[Operation] If the amount of plastic deformation necessary for manifesting the characteristics of the part is known, it is not necessary to give extra plastic deformation.

In the present invention, the shape of the aluminum alloy powder grains observed in the internal structure is adopted as an index of the plastic deformation, and the amount of plastic deformation necessary for manifesting the characteristics is determined.

The alloy powder grains are plastically deformed by the pressure applied for densification and imparting of the shape of the parts and extend in the direction perpendicular to the direction of the applied pressure, and the aspect ratio a / of the alloy powder grains after solidification is b becomes large. There is a correlation between this aspect ratio and the mechanical properties of parts, and the aspect ratio is 3
If it exceeds, it is considered that the oxide film on the surface of the grains will be destroyed at once, and the strength of the component will be rapidly increased.

The forging pressure and compression ratio at which the average aspect ratio of the portion requiring mechanical strength is 3 or more can be obtained in advance by experiments, and the forging pressure and compression ratio can be controlled to obtain the required amount of the required amount in the required portion. Gives plastic deformation. By doing so, it is possible to prevent over-specification of the material and eliminate unnecessary processing.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 3 is a flowchart based on the flow shown in FIG.
A forged body 10 having the shape shown in was produced. This forged body 10
Is a preformed body 1 of FIG. 2 (a) obtained by cold compaction of rapidly solidified aluminum alloy powder at 430 ° C. or higher,
It is heated to 530 ° C. or below, and the molds 2 and 3 shown in FIG.
It is made by immediately hot forging using (upper die and lower die), and the portion of the large diameter head 11 is compressed by a necessary amount to densify it to a relative density of 99% or more. The central portion of the head located on the extension thereof is hardly compressed by the molds 2 and 3.

A test piece 4 shown in FIG. 4 was cut out from the forged body 10 shown in FIG. 3 and subjected to a tensile test. The test piece 4 was cut out in the direction shown in FIGS. 3 (a) and 3 (b) from the portion of the head 11 to which the necessary plastic deformation was applied. Figure 3
(C) is an image view of the internal structure of the test piece 4.

Next, the test piece 4 after the tensile test is parallel to the axial direction (substantially right angle to the fracture surface 4a) and the direction in which the principal stress acts during forging (the direction of arrow A in FIG. 3A). Cut at plane 5 in Figure 5 (this is perpendicular to the paper),
The cut surface was mirror-polished, and the polished surface was etched to observe the structure. The observed surface is enlarged and shown in FIG. In FIG. 6A, the white and contrasted elliptical particles are the raw material aluminum alloy powder particles after the tissue densification. The major axis length a and the minor axis length b of the alloy powder particles
(See FIG. 6B) and measure the aspect ratio a of the grain.
/ B was determined. Then, with respect to one test piece, the aspect ratio of the alloy powder particles was measured at 15 points, and the average value was obtained for each test piece.

Further, as a comparative example, a test piece was cut out from a forged body manufactured by the flow shown in FIG. 7 (a billet whose entire body was once densified was hot worked) and the same test and observation as above were performed.

The following are details of the test.

-Experimental Example 1-Test pieces were made from the materials shown in Table 1 based on the flow of FIG. 1 and the forged body manufactured under the conditions, and the materials shown in Table 2 based on the flow of FIG. 7 and the forged body manufactured under the conditions. Was cut out and subjected to a tensile test at room temperature. The results are shown in Table 5.

FIG. 8 shows the results of investigation of the relationship between the tensile strength of the test piece and the average aspect ratio of the alloy powder particles in the test piece. FIG. 8 shows the relationship between the breaking elongation of the test piece and the average aspect ratio of the alloy powder particles in the piece. The results of the investigation are shown in FIG.

As can be seen from FIGS. 8 and 9, there is a correlation between the aspect ratio of the raw material aluminum alloy powder particles in the alloy after densification and the mechanical properties of the alloy, and the average aspect ratio of 3 or more ( Sample numbers 1 to 47) are shown in FIG.
The same tensile strength as that of the forged body (Sample Nos. 66 and 67) obtained by the flow of No. 2 was obtained, and those having a large average aspect ratio had comparable tensile elongation values.

The preforms whose heating temperature is lower than 430 ° C. (Sample Nos. 48 to 55) have lower elongation values and whose heating temperature exceeds 530 ° C. (Sample Nos. 56 to 6).
In 5), the tensile strength is greatly reduced.

-Experimental Example 2-A test piece is made from the material shown in Table 3 based on the flow of FIG. 1 and the forged body produced under the conditions, and the material shown in Table 4 based on the flow of FIG. 7 and the forged body produced under the conditions. Was cut out and subjected to a tensile test at room temperature. The results are shown in Table 6.

FIG. 10 shows the results of investigation of the relationship between the tensile strength of the test piece and the average aspect ratio of the alloy powder particles in the test piece. FIG. 10 shows the relationship between the breaking elongation of the test piece and the average aspect ratio of the alloy powder particles in the piece. Figure 1 shows the survey results
1 shows each.

As can be seen from FIGS. 10 and 11, there is a correlation between the aspect ratio of the raw material aluminum alloy powder particles in the alloy after densification and the mechanical properties of the alloy, and those having an average aspect ratio of 3 or more ( (Sample Nos. 68 to 114)
Is a forged body (sample numbers 133, 13
The same tensile strength as that of 4) was obtained, and those having a large average aspect ratio had comparable tensile elongation values.

The preforms having a heating temperature of less than 430 ° C. (Sample Nos. 115 to 122) had a lower elongation value and had a heating temperature of more than 530 ° C. (Sample No. 12).
3 to 132), the tensile strength is greatly reduced.

-Experimental Example 3-Test pieces were made from the materials shown in Table 1 based on the flow of FIG. 1 and the forged body manufactured under the conditions, and the materials shown in Table 2 based on the flow of FIG. 7 and the forged body manufactured under the conditions. Was cut out and subjected to a tensile test at 200 ° C. The results are shown in Table 7.

FIG. 12 shows the results of investigation of the relationship between the tensile strength of the test piece and the average aspect ratio of the alloy powder particles in the test piece. FIG. 12 shows the relationship between the breaking elongation of the test piece and the average aspect ratio of the alloy powder particles in the piece. Figure 1 shows the survey results
3 respectively.

As can be seen from FIGS. 12 and 13, there is a correlation between the aspect ratio of the raw material aluminum alloy powder particles in the alloy after densification and the mechanical properties of the alloy, and the average aspect ratio of 3 or more ( Sample number 133-14
2) is a forged body (Sample No. 151,
The same tensile strength as 152) is obtained.

The tensile elongation of the alloy decreases as the average aspect ratio becomes smaller, but the tensile elongation of alloys with a large average aspect ratio is comparable. Those having an average aspect ratio of 3 or less (Sample Nos. 143-150)
Has a poor tensile elongation at 200 ° C.

-Experimental Example 4-Test pieces were made from the materials shown in Table 3 based on the flow of FIG. 1 and the forged body manufactured under the conditions, and the materials shown in Table 4 based on the flow of FIG. 7 and the forged body manufactured under the conditions. Was cut out and subjected to a tensile test at 200 ° C. The results are shown in Table 8.

FIG. 14 shows the results of investigation of the relationship between the tensile strength of the test piece and the average aspect ratio of the alloy powder particles in the test piece. FIG. 14 shows the relationship between the breaking elongation of the test piece and the average aspect ratio of the alloy powder particles in the piece. Figure 1 shows the survey results
5 shows each.

There is a correlation between the aspect ratio of the raw material aluminum alloy powder particles and the mechanical properties of the alloy, and those having an average aspect ratio of 3 or more (Sample Nos. 153 to 160) are:
Forged body according to the flow of FIG. 7 (Sample Nos. 169 and 170)
The same tensile strength is obtained, and those with a large average aspect ratio have comparable tensile elongation values.

If the average aspect ratio of the raw material alloy powder particles in the alloy is 3 or less (Sample Nos. 161 to 168),
Both the tensile strength and tensile elongation at 0 ° C are small.

-Experimental Example 5- Using a rapidly solidified aluminum alloy powder having the composition shown in Table 10, a test piece was cut out from a forged body produced under the conditions shown in the flow chart of Fig. 1 and Table 9, and a tensile test was conducted at 200 ° C. . The results are shown in Table 10.

The starting material used in this experiment was Si: 10.
˜40% by mass, one or more elements selected from V, Cr, Mn, Fe, Co and Ni in total is 3 to 11% by mass,
Ti: 1 to 3% by mass, the balance substantially consisting of Al.

In the aluminum alloy of this composition, Si improves the wear resistance of the alloy, and V, Cr, Mn, F
e, Co, Ni and Ti are Al-V type, Al-Cr type, A
The 1-Fe-based, Al-Co-based, Al-Ti-based fine intermetallic compounds and the binary intermetallic compounds of Al-Fe-Ni are crystallized in the Al matrix to improve the heat resistance of the matrix. If the addition amount of Ti, Ti, or a transition metal is insufficient, the tensile strength at 200 ° C. decreases (Sample No. 186,
188, 190), and when its Si, Ti or transition metal is added excessively, the tensile elongation at 200 ° C. decreases (Sample Nos. 187, 189, 191). Sample number 171
In Examples 185 to 185, those elements are within the specified range, and favorable values are obtained for both the tensile strength and the tensile elongation at 200 ° C.

--Experimental Example 6-- Using a rapidly solidified aluminum alloy powder having the composition shown in Table 11, a test piece was cut out from a forged body produced under the conditions shown in the flow chart of FIG. 1 and shown in Table 9 and subjected to a tensile test at 200.degree. . The results are shown in Table 11.

The starting material used in this experiment was Si: 10.
~ 30 mass%, Ti, V, Cr, Mn, Fe, Co, N
One or more elements selected from i, Mo, and W are 3 to 10% by mass in total, Zr: 1 to 3% by mass, rare earth elements (including misch metal): 3 to 6% by mass, and the balance is substantially Is composed of Al.

The aluminum alloy of this composition was used in Experimental Example 5
However, since the rare earth element has a function of refining the aluminum-transition metal intermetallic compound and the silicon crystal, and the simultaneous addition of Zr with the rare earth element is effective, the rare earth element and Zr are added. On the other hand, Ti is added to Zr at the same time as it prevents the refinement of crystal grains, so that the composition does not contain Ti, and W is added if necessary. Also in the alloy having this composition, the tensile strength and the elongation at 200 ° C. are lowered due to the excess or deficiency of Si, transition metal, Zr, and rare earth elements (Sample Nos. 202 to 209). 200 ℃ for each element within the specified range (Sample Nos. 192-201)
Although the tensile strength at 100 ° C. is slightly inferior to that of the composition shown in Table 10, the elongation at 200 ° C. is extremely high in all cases.

[0042]

[Table 1]

[0043]

[Table 2]

[0044]

[Table 3]

[0045]

[Table 4]

[0046]

[Table 5]

[0047]

[Table 6]

[0048]

[Table 7]

[0049]

[Table 8]

[0050]

[Table 9]

[0051]

[Table 10]

[0052]

[Table 11]

[0053]

As described above, according to the present invention, the average aspect ratio of the aluminum alloy powder grains observed in the structure of only the portion requiring mechanical strength is a / b. Since it is plastically deformed to the point where ≧ 3, over-spec of aluminum alloy parts produced by using rapidly solidified aluminum alloy powder as a starting material is suppressed, and the alloy is densified and the shape of parts is given. At the same time, it is possible to reduce unnecessary processing.

Further, by reducing wasteful processing, it is possible to simplify equipment and improve product yield.

[Brief description of drawings]

FIG. 1 is a diagram showing a manufacturing flow of a component of the present invention.

FIG. 2 (a) is a view showing the shape and dimensions of a preform. (B) Diagram showing the shape of the forged body and the forging method

3 (a) is a perspective view of the forged body of FIG. 2 (b). (B) The same plan view (C) Image of internal structure of test piece

FIG. 4 is a diagram showing the shape and dimensions of a test piece.

FIG. 5 is a diagram showing a test piece fractured in a tensile test.

FIG. 6A is a diagram showing an internal structure of a test piece, and FIG. 6B is a diagram showing an aspect ratio of aluminum alloy powder grains in the structure.

FIG. 7 is a diagram showing a flow of manufacturing parts by a conventional method.

FIG. 8 is a diagram showing the relationship between the average aspect ratio and tensile strength in Experimental Example 1.

FIG. 9 is a diagram showing the relationship between the average aspect ratio and breaking elongation in Experimental Example 1.

FIG. 10 is a graph showing the relationship between the average aspect ratio and tensile strength in Experimental Example 2.

FIG. 11 is a graph showing the relationship between the average aspect ratio and elongation at break in Experimental Example 2.

FIG. 12 is a diagram showing the relationship between the average aspect ratio and tensile strength in Experimental Example 3.

FIG. 13 is a graph showing the relationship between the average aspect ratio and breaking elongation in Experimental Example 3.

FIG. 14 is a diagram showing the relationship between average aspect ratio and tensile strength in Experimental Example 4.

FIG. 15 is a diagram showing the relationship between average aspect ratio and breaking elongation in Experimental Example 4.

[Explanation of symbols]

1 Preform A few molds 4 test pieces 4a fracture surface 5 piece cut surface 10 Forged body 11 heads 12 Shaft

[Procedure amendment]

[Submission date] February 28, 2002 (2002.2.2)
8)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction content]

[Document name] Statement

Title: Aluminum alloy part and method of manufacturing the same

[Claims]

2. A rapidly solidified aluminum alloy powder as a starting material, wherein Si: 10 to 30% by mass, and one or more elements selected from Ti, V, Cr, Mn, Fe, Co, Ni, Mo and W. 3-10% by mass in total, Zr: 1-3% by mass, rare earth element (including misch metal): 3-6% by mass, and a composition having a balance substantially consisting of Al is used. Aluminum alloy parts.

3. Si: 10 to 30% by mass, one or more elements selected from Ti, V, Cr, Mn, Fe, Co, Ni, Mo and W in total 3 to 10% by mass, Zr: 1-3 mass%, rare earth element (including misch metal): 3-6 mass%, a step of atomizing a molten metal having a composition in which the balance substantially consists of Al to obtain rapidly solidified aluminum alloy powder, the rapidly solidified aluminum A step of cold compacting the alloy powder to obtain a preformed body, a step of heating the preformed body to a temperature of 430 ° C. or higher and 530 ° C. or lower, immediately hot plastic working the heated preformed body, A step of performing densification with a relative density of 99% or more in a necessary part and imparting a part shape together. Through the above steps, an aluminum alloy part is manufactured, and in the step of densifying and imparting a part shape, a part machine is used. Aspect ratio of aluminum alloy powder particles after solidification, which is observed in a plane parallel to the direction in which maximum stress is applied, by giving the amount of plastic deformation required to develop characteristics only to the part requiring mechanical strength. The method of manufacturing an aluminum alloy part is characterized in that the average value of a is a and the minor axis length is b and the minor axis length is b, and a structure represented by a / b ≧ 3 is obtained.

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention eliminates wasteful steps for avoiding excessive specifications of aluminum alloy parts manufactured by powder metallurgy, which have excellent strength, heat resistance and creep resistance. And a manufacturing method for manufacturing the same.

[0002]

2. Description of the Related Art Aluminum alloy parts manufactured by pressing and forging using a rapidly solidified aluminum alloy powder obtained by an atomizing method as a starting material include, for example,
JP 2001-98304 A describes a piston for internal combustion engine, a cylinder sleeve, a connecting rod, a valve lifter,
There are various things such as rocker arms and scroll plates for compressors.

An oxide film is present on the surface of the rapidly solidified aluminum alloy powder produced by atomization. Therefore, when the powder is used as a raw material for making parts, the strength and toughness required for the parts are ensured. In addition, it is necessary to destroy the oxide film on the surface and promote the bonding of the powder.

As a technique therefor, the above-mentioned Japanese Patent Laid-Open No. 2001
-98304 is a raw material which is compacted into a metal lump, which is then pressed hot to densify the structure, and then upset to produce an aluminum alloy billet for forging. To manufacture forged pistons for internal combustion engines.

[0005]

In the prior art disclosed in the above publications, the compacted powder compact is once densified, and the material in the entire region is plastically deformed by upsetting. However, the plastic deformation is required to break the oxide film on the surface of the raw material powder to strengthen the material, such as the ceiling of the piston where the load is high, whereas according to the conventional method, a large mechanical strength is required. There is a high possibility that large plastic flow will occur even in the parts that do not require, and the material properties will be over-specified.

The overspec of its material properties increases unnecessary processing. However, it is not known which part of the component should be finally added with the amount of plastic deformation, and thus it is impossible to prevent over-spec which increases unnecessary machining.

The present invention has been made in view of the above points, and an object thereof is to provide an aluminum alloy part in which over-spec is eliminated by using the cross-sectional structure of the part as an index and a method for manufacturing the part. There is.

[0008]

In order to solve the above-mentioned problems, in the present invention, the amount of plastic deformation required for exhibiting the characteristics is given only to the portion requiring mechanical strength in the process of densifying the structure. The average value of the aspect ratio of the aluminum alloy powder particles observed in the plane in which the internal structure of the site is parallel to the direction requiring mechanical strength is the major axis length of the powder particles is a, and the minor axis length is b. As a result, an aluminum alloy part having a structure represented by a / b ≧ 3 is provided.

As a starting material, Si: 10-30
Mass%, Ti, V, Cr, Mn, Fe, Co, Ni, M
One or more elements selected from o and W are 3-1 in total
A part using a rapidly solidified aluminum alloy powder having a composition of 0 mass%, Zr: 1 to 3 mass%, rare earth element (including misch metal): 3 to 6 mass%, and the balance substantially consisting of Al is provided.

Further, regarding the starting material having the specified composition, a step of atomizing the molten metal to obtain a rapidly solidified aluminum alloy powder having a desired composition, the rapidly solidified aluminum alloy powder being cold compacted and preliminarily prepared The step of obtaining a compact, the step of heating the preform to a temperature of 430 ° C. or higher and 530 ° C. or lower, the heated preform is immediately subjected to hot plastic working, and the relative density of necessary parts is 99% or higher. In addition to manufacturing the aluminum alloy parts through the steps of performing part shape imparting and the above steps, in the densification and part shape imparting steps, it is necessary to develop characteristics only in the parts that require mechanical strength of the parts. The average value of the aspect ratio of the aluminum alloy powder particles after solidification observed in a plane parallel to the direction in which the maximum stress is applied, given the amount of plastic deformation. , Powder particle major axis length a, short axis as b, providing together a method of manufacturing an aluminum alloy part, wherein the obtaining tissue represented by a / b ≧ 3.

[0011]

[Operation] If the amount of plastic deformation necessary for manifesting the characteristics of the part is known, it is not necessary to give extra plastic deformation.

In the present invention, the shape of the aluminum alloy powder grains observed in the internal structure is adopted as an index of the plastic deformation, and the amount of plastic deformation necessary for manifesting the characteristics is determined.

The alloy powder grains are plastically deformed by the pressure applied for densification and imparting of the shape of the parts and extend in the direction perpendicular to the direction of the applied pressure, and the aspect ratio a / of the alloy powder grains after solidification is b becomes large. There is a correlation between this aspect ratio and the mechanical properties of parts, and the aspect ratio is 3
If it exceeds, it is considered that the oxide film on the surface of the grains will be destroyed at once, and the strength of the component will be rapidly increased.

The forging pressure and compression ratio at which the average aspect ratio of the portion requiring mechanical strength is 3 or more can be obtained in advance by experiments, and the forging pressure and compression ratio can be controlled to obtain the required amount of the required amount in the required portion. Gives plastic deformation. By doing so, it is possible to prevent over-specification of the material and eliminate unnecessary processing.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 3 is a flowchart based on the flow shown in FIG.
A forged body 10 having the shape shown in was produced. This forged body 10
Is a preformed body 1 of FIG. 2 (a) obtained by cold compaction of rapidly solidified aluminum alloy powder at 430 ° C. or higher,
It is heated to 530 ° C. or below, and the molds 2 and 3 shown in FIG.
It is made by immediately hot forging using (upper die and lower die), and the portion of the large diameter head 11 is compressed by a necessary amount to densify it to a relative density of 99% or more. The central portion of the head located on the extension thereof is hardly compressed by the molds 2 and 3.

A test piece 4 shown in FIG. 4 was cut out from the forged body 10 shown in FIG. 3 and subjected to a tensile test. The test piece 4 was cut out in the direction shown in FIGS. 3 (a) and 3 (b) from the portion of the head 11 to which the necessary plastic deformation was applied. Figure 3
(C) is an image view of the internal structure of the test piece 4.

Next, the test piece 4 after the tensile test is parallel to the axial direction (substantially right angle to the fracture surface 4a) and the direction in which the principal stress acts during forging (the direction of arrow A in FIG. 3A). Cut at plane 5 in Figure 5 (this is perpendicular to the paper),
The cut surface was mirror-polished, and the polished surface was etched to observe the structure. The observed surface is enlarged and shown in FIG. In FIG. 6A, the white and contrasted elliptical particles are the raw material aluminum alloy powder particles after the tissue densification. The major axis length a and the minor axis length b of the alloy powder particles
(See FIG. 6B) and measure the aspect ratio a of the grain.
/ B was determined. Then, with respect to one test piece, the aspect ratio of the alloy powder particles was measured at 15 points, and the average value was obtained for each test piece.

Further, as a comparative example, a test piece was cut out from a forged body manufactured by the flow shown in FIG. 7 (a billet whose entire body was once densified was hot worked) and the same test and observation as above were performed.

The following are details of the test.

-Experimental Example 1- Test pieces were made from the materials shown in Table 1 based on the flow of FIG. 1 and the forged body produced under the conditions, and the materials shown in Table 2 based on the flow of FIG. 7 and the forged body produced under the conditions. Was cut out and subjected to a tensile test at room temperature. The results are shown in Table 3 .

FIG. 8 shows the results of investigation of the relationship between the tensile strength of the test piece and the average aspect ratio of the alloy powder particles in the test piece. FIG. 8 shows the relationship between the breaking elongation of the test piece and the average aspect ratio of the alloy powder particles in the piece. respectively show findings in Fig.

As can be seen from FIGS. 8 and 9, there is a correlation between the aspect ratio of the raw material aluminum alloy powder particles in the alloy after densification and the mechanical properties of the alloy, and the average aspect ratio of 3 or more ( Sample numbers 68-114)
Forged body according to the flow of FIG. 7 (Sample Nos. 133 and 134)
The same tensile strength was obtained, and those with a large average aspect ratio had comparable tensile elongation values.

The preforms whose heating temperature is lower than 430 ° C. (Sample Nos. 115 to 122) have a lower elongation value and whose heating temperature exceeds 530 ° C. (Sample No. 12).
3 to 132), the tensile strength is greatly reduced.

-Experimental Example 2-A test piece is made from the material shown in Table 1 based on the flow of FIG. 1 and the forged body produced under the conditions, and the material shown in Table 2 based on the flow of FIG. 7 and the forged body produced under the conditions. Was cut out and subjected to a tensile test at 200 ° C. The results are shown in Table 4 .

Further, in the tensile strength and the test piece of test piece 1 0 findings of the relationship between the average aspect ratio of the alloy powder particles, the alloy powder particles in the elongation at break and pieces of the test pieces average aspect ratio Figure 1 shows the results of the relationship survey
1 shows each.

There is a correlation between the aspect ratio of the raw material aluminum alloy powder particles and the mechanical properties of the alloy, and those having an average aspect ratio of 3 or more (Sample Nos. 153 to 160) are:
Forged body according to the flow of FIG. 7 (Sample Nos. 169 and 170)
The same tensile strength is obtained, and those with a large average aspect ratio have comparable tensile elongation values.

If the average aspect ratio of the raw material alloy powder particles in the alloy is 3 or less (Sample Nos. 161 to 168), 20
Both the tensile strength and tensile elongation at 0 ° C are small.

-Experimental Example 3- Using a rapidly solidified aluminum alloy powder having the composition shown in Table 6 , a test piece was cut out from a forged body produced under the conditions shown in the flow of FIG. 1 and Table 5, and a tensile test was conducted at 200 ° C. . The results are shown in Table 6 .

The starting material used in this experiment was Si: 10.
~ 30 mass%, Ti, V, Cr, Mn, Fe, Co, N
One or more elements selected from i, Mo, and W are 3 to 10% by mass in total, Zr: 1 to 3% by mass, rare earth elements (including misch metal): 3 to 6% by mass, and the balance is substantially Is composed of Al.

The aluminum alloy of this composition, the rare earth element aluminum - It works by refining the transition metal intermetallic compound and the silicon crystal, rare earth elements since the rare earth element is simultaneous addition of Zr valid And Zr, on the other hand,
If Ti is added at the same time as Zr, grain refining is hindered. Therefore, the composition does not include Ti, and W is added as necessary. Alloys of this composition also include Si, transition metals,
Due to the excess or deficiency of Zr and rare earth elements, the tensile strength and elongation at 200 ° C. decrease (Sample Nos. 202 to 209). Each element is within the specified range (Sample No. 192-201)
Has a tensile strength at 200 ° C. of 1 to 1% for Ti instead of Zr.
Although some of them are inferior to those of the composition with 3% by mass added , the elongation at 200 ° C. is extremely high in all cases.

[0031]

[Table 1]

[0032]

[Table 2]

[0033]

[Table 3]

[0034]

[Table 4]

[0035]

[Table 5]

[0036]

[Table 6]

[0037]

As described above, according to the present invention, the average aspect ratio of the aluminum alloy powder grains observed in the structure of only the portion requiring mechanical strength is a / b. Since it is plastically deformed to the point where ≧ 3, over-spec of aluminum alloy parts produced by using rapidly solidified aluminum alloy powder as a starting material is suppressed, and the alloy is densified and the shape of parts is given. At the same time, it is possible to reduce unnecessary processing.

Further, by reducing wasteful processing, it is possible to simplify equipment and improve product yield.

[Brief description of drawings]

FIG. 1 is a diagram showing a manufacturing flow of a component of the present invention.

FIG. 2 (a) is a view showing the shape and dimensions of a preform. (B) Diagram showing the shape of the forged body and the forging method

3 (a) is a perspective view of the forged body of FIG. 2 (b). (B) The same plan view (C) Image of internal structure of test piece

FIG. 4 is a diagram showing the shape and dimensions of a test piece.

FIG. 5 is a diagram showing a test piece fractured in a tensile test.

FIG. 6A is a diagram showing an internal structure of a test piece, and FIG. 6B is a diagram showing an aspect ratio of aluminum alloy powder grains in the structure.

FIG. 7 is a diagram showing a flow of manufacturing parts by a conventional method.

FIG. 8 is a diagram showing the relationship between the average aspect ratio and tensile strength in Experimental Example 1.

FIG. 9 is a diagram showing the relationship between the average aspect ratio and breaking elongation in Experimental Example 1.

FIG. 10 is a graph showing the relationship between the average aspect ratio and tensile strength in Experimental Example 2.

FIG. 11 is a graph showing the relationship between the average aspect ratio and elongation at break in Experimental Example 2.

[Explanation of symbols] 1 Preform A few molds 4 test pieces 4a fracture surface 5 piece cut surface 10 Forged body 11 heads 12 Shaft

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   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takao Nishioka             Sumitomo Electric Co., Ltd. 1-1-1 Koyo Kita, Itami City             Business Itami Manufacturing Co., Ltd. F term (reference) 3G016 BB02 BB09 EA08 EA10 EA24                       FA04 FA11 FA15                 4K018 AA16 BA07 BB01 EA41 EA44

Claims (5)

[Claims] 1. A component manufactured by using a rapidly solidified aluminum alloy powder obtained by atomizing a molten metal having a predetermined composition as a starting material, through a powder compacting process and a hot plastic working process, which requires mechanical strength. The average value of the aspect ratio of the aluminum alloy powder particles observed in the plane parallel to the orientation requiring mechanical strength is given the amount of plastic deformation required for the characteristic expression only to the site, and the internal structure of the site, An aluminum alloy part characterized by having a structure represented by a / b ≧ 3 in which the major axis length of powder particles is a and the minor axis length is b. 2. A rapidly solidified aluminum alloy powder as a starting material, wherein Si: 10 to 40% by mass, and one or more elements selected from V, Cr, Mn, Fe, Co and Ni in total is 3 to 11% by mass. %, Ti: 1 to 3 mass%, and the aluminum alloy part according to claim 1, which has a composition in which the balance substantially consists of Al. 3. A rapidly solidified aluminum alloy powder as a starting material, which comprises Si: 10 to 30 mass%, one or more elements selected from Ti, V, Cr, Mn, Fe, Co, Ni, Mo and W. 3-10% by mass in total, Zr: 1-3% by mass, rare earth element (including misch metal): 3-6% by mass, and a composition having a balance substantially consisting of Al is used. Aluminum alloy parts. 4. Si: 10 to 40% by mass, V, Cr, Mn, Fe, Co, and Ni in total of 3 to 11% by mass, and Ti: 1 to 3% by mass. A step of atomizing a molten metal having a composition with the balance substantially consisting of Al to obtain a rapidly solidified aluminum alloy powder, a step of cold compacting the rapidly solidified aluminum alloy powder to obtain a preform, and its preforming A step of heating the body to a temperature of 430 ° C. or higher and 530 ° C. or lower, a step of subjecting the heated preformed body to hot plastic working immediately, and densification of a necessary portion to a relative density of 99% or more and imparting a part shape together While manufacturing aluminum alloy parts through each of the above steps, in the step of densifying and imparting the shape of parts, plastic deformation of the amount necessary for characteristic expression is given only to the parts requiring mechanical strength of the parts, The average value of the aspect ratios of the aluminum alloy powder particles after solidification observed in a plane parallel to the direction in which the maximum stress is applied is the major axis length of the powder particles is a and the minor axis length is b. As a method of manufacturing an aluminum alloy part, a structure represented by a / b ≧ 3 is obtained. 5. Si: 10 to 30% by mass, a total of 3 to 10% by mass of one or more elements selected from Ti, V, Cr, Mn, Fe, Co, Ni, Mo and W, Zr: 1-3 mass%, rare earth element (including misch metal): 3-6 mass%, a step of atomizing a molten metal having a composition in which the balance substantially consists of Al to obtain rapidly solidified aluminum alloy powder, the rapidly solidified aluminum A step of cold compacting the alloy powder to obtain a preformed body, a step of heating the preformed body to a temperature of 430 ° C. or higher and 530 ° C. or lower, immediately hot plastic working the heated preformed body, A step of performing densification with a relative density of 99% or more in a necessary part and imparting a part shape together. Through the above steps, an aluminum alloy part is manufactured, and in the step of densifying and imparting a part shape, a part machine is used. The amount of plastic deformation required to develop the characteristics is given only to the part that requires static strength, and the aspect ratio of the aluminum alloy powder particles after solidification observed in a plane parallel to the direction in which the maximum stress is applied to that part. A method for manufacturing an aluminum alloy component, wherein an average value is a structure in which a / b ≧ 3 is obtained, where a major axis length of powder particles is a and a minor axis length is b.