JPH01316434A - Heat-resistant aluminum alloy material and its manufacture - Google Patents

Abstract

PURPOSE:To easily manufacture the title Al alloy material suitable for a material in which high temp. strength is required by forming the molten metal of an Al alloy in which the content of Fe, Zn, etc., is limited into powder by a gas atomizing method, subjecting it to hot compacting and regulating the average size of an intermetallic compound. CONSTITUTION:An alloy contg., by weight, 5.5-15% Fe, 0.1-5% Zn and one or more kinds among 0.5-15% Co, 0.7-15% Cr, 0.3-10% Zr, 0.3-10% V, 0.5-10% Ce, 0.2-8% W, 0.5-10% Ti, 0.2-10% Mo, 0.5-15% Mn and 0.2-10% Cu, in which the total amt. of all elements to be added is regulated to <=25% and the balance Al with inevitable impurities is refined. The molten metal is subjected to rapid solidification by a gas atomizing method to form powder and is subjected to hot compacting by an ordinary method. The average size of an inermetallic compound contg. Fe finely dispersing at the time of the above rapid solidification is then regulated to the range of 0.07-1mum. By this method, the heat-resistant Al alloy material can easily be obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an aluminum alloy material with excellent heat resistance and a method for manufacturing the same using a powder metallurgy method.

(Prior Art) Materials for automobile engine parts, gas turbine impellers, aircraft parts, etc. are required to have high-temperature strength at 100 to 400°C. If these materials are aluminum alloys, many advantages associated with weight reduction can be obtained. However, aluminum and its alloys generally have low strength at high temperatures.
For example, aluminum alloy (AA2) has excellent strength at room temperature.
01B, 2218.4032, etc.) at 200℃
At temperatures above this, the strength decreases significantly.

In response to this, in recent years, an aluminum powder metallurgy method has been developed in which a heat-resistant aluminum alloy is produced by adding large amounts of various transition elements to aluminum and processing the powder or ribbon-like thin strip obtained by rapid solidification into a heat-resistant aluminum alloy. and AJL-
8Fe-4Ce, AlAl1-8Fe-2, A sentence-8F
Alloys such as e-2Go are provided.

The manufacturing process using powder metallurgy for aluminum alloys involves rapid solidification of molten alloys into powder, ribbon, or flake shapes using the atomization method, y-roll method, or spray roll method, which is then cooled. After forming into a compact with a density ratio (ratio to true density) of 70% or more, the can is sealed, vacuum degassing is performed, and then hot processing is performed to form a compact with a density ratio of 10%.
A commonly used method is to form a 0% billet and further form it by extrusion, forging, etc. in order to increase the bonding force between particles.

(Problem to be solved by the invention) However, the above A Jl -8F e -4Ce,
A Jl-8Fe-2M0. Al1-8Fe-2Go
These alloys are alloys that exhibit excellent heat resistance only when the molten metal is ultra-rapidly solidified at 105°C/sec or higher and then compression molded. Cooling rate 102-105
℃/sec), there was a problem that sufficient strength and heat resistance could not be obtained.

On the other hand, ultra-rapid solidification methods that can achieve a cooling rate of 105°C/sea or higher include the quench roll method and melt spinning method, but all of them require special manufacturing equipment and solidification technology, so they do not increase costs. In addition, the ultra-rapidly solidified material produced by the quench roll method is in the form of ribbons or flakes, and as it is unsuitable for compression molding, it is necessary to cut it into small pieces. Therefore, there was a problem of high cost.

Therefore, an object of the present invention is to provide a heat-resistant aluminum alloy that is easy to manufacture and inexpensive and can be obtained by compression molding a gas atomized powder, and a method for manufacturing the same.

(Means for Solving the Problems) The present inventors have conducted intensive research to solve the above problems, and as a result, they have achieved the above objects by forming gas atomized powder using a molten metal of a specific aluminum alloy composition. Based on this finding, the present invention was completed.

That is, 1 the present invention includes (1) Fe 5.0 to 15% by weight (hereinafter simply referred to as %), Zn 0.1 to 5%, and N
i0.5-15%, Co 0.5-15%, Cr0.
7S15%, Zr0.3~IOX, V0.3~1
0%;, Ce 0.5-10%, W0.2
~8%, Ti 0.5~10%;, Mo 002~
10%, Mn 0.5-15% and Cu 0.2-10
%, and the total amount of added elements is 2.
5% or less, the balance is Al and unavoidable impurities, and the average size of the intermetallic compound containing Fe is 0.07 to I
(2) A heat-resistant aluminum alloy material characterized by being gm, and (2) containing Fe 5.0-15%, Zn 0.1-5%, Ni 0.5-15%, Co 0
．． 5-15%, Cr0.7-15X, Z r 0
．． :l ~10%, V 0.3~10%, Ce 0.
5-10%, W0.2-8%, Ti0.5-10%, M
o 0.2-10%, Mn 0.5-15% and C
A molten AJI alloy containing one or more of 12 to 10% of uO, the total amount of added elements being 25% or less, and the remainder containing Al and unavoidable impurities is rapidly solidified by gas atomization to form a powder. Formed.

Provided is a method for producing a heat-resistant aluminum alloy material having the above composition and having an average size of Fe-containing intermetallic compound of 0.07 to IILm, the method comprising hot compression molding the material. It is something.

The action of each component in the aluminum alloy material according to the present invention and the reason for limiting its content are as follows.

Fe content shall be 5.0-15%. Fe is finely dispersed as an intermetallic compound containing Fe during rapid solidification by gas atomization, and has the effect of increasing high-temperature strength. This effect is not sufficient when the Fe content is less than 5.0%, and when the Fe content exceeds 15%, not only is the degree of this effect saturated, but the intermetallic compound becomes coarse.

Zn content shall be 0.1-5%. Zn is.

By forming a solid solution in Al, it has the effect of improving the strength, and a part of it precipitates finely as an intermetallic compound that does not contain Fe, and has the effect of improving the room temperature strength. These effects are not sufficient when the Zn content is less than 0.1%, and on the other hand, when the Zn content exceeds 5%, the effects are saturated, leading to an increase in cost.

Ni, C0. Cr, Zr, V, Ce, W.

Ti and Mo have the effect of thermally stabilizing the intermetallic compound containing Fe, and this effect increases the high-temperature strength. Like Zn, Mn and Cr have the effect of improving the strength by being dissolved in A4 as a solid solution, and the effect of improving the strength by partially precipitating finely. Ni, C0
．． Cr, Zr, V, Ce, W, Ti, M0. Mn, Cu
are respectively Ni0.5-15% and Co0.5-15%
, Cr0.7-15%, Zr 0.3-10%, V
0.3~10%, Ce095~10%, W (1,2~
8%, Ti 0.5-10%, Mo 0.2-10%, M
1 in the range of n 0.5-15%, Cu 0.2-10%
Add seeds or a combination of two or more. If the amount added is less than the lower limit, the effect will not be sufficient, and if it exceeds the upper limit, not only will the degree of effect become saturated, but the cost will increase.

Further, the total amount of all additive elements is 25% or less. When this total amount exceeds 25%, the effect not only becomes saturated, but also
resulting in increased costs.

Further, even if 0.5 to 500 ppm of unavoidable impurities such as Be, B, Na, and Ca are contained in A2, the characteristics are not affected in any way.

Next, in the present invention, the average size of the intermetallic compound containing Fe in the aluminum alloy having the above composition is 0.07~
It is set to 1 μm.

In producing the aluminum alloy material of the present invention, a molten aluminum alloy having the above composition is rapidly solidified by gas atomization at a cooling rate of preferably 10 to 105°C/sec to form a powder, which is then hot heated. compression molding process. The gas atomization method is already widely used as a method for producing pure Al powder for paints and rocket solid fuel, and by using its production equipment, it is possible to easily produce large amounts of alloy powder. . Therefore, using the gas atomization method, which has established manufacturing technology and already has mass production plants, is
It has great benefits in terms of cost. In addition, since the rapidly solidified material produced by the gas atomization method is a particulate powder,
It has the advantage of being easier to handle and compression mold than ribbon-like thin strips, flakes, etc. produced by the quench roll method, etc., and is advantageous in terms of production cost.

However, in the gas atomization method, the size of the intermetallic compound containing Fe that is finely dispersed during rapid solidification is reduced to 0.077zm.
It is currently difficult to make it smaller. Generally, the size of compounds in a rapidly solidified material decreases as the solidification rate increases. For example, in a powder with a particle size of 54 m or less, the size of the intermetallic compound containing Fe is 0.07 JLm or less, but the proportion of powder of 5 Bm or less in powder produced by the gas atomization method is as low as about 2 to 3%. Classifying and using only this results in a significant increase in cost. Therefore, in this case, the size of the intermetallic compound containing Fe is 0.07g.
It is virtually impossible to make it smaller than m. However, 1. Normally, F
The average size of intermetallic compounds containing e is 0.07 to 1 μm
It is. The size of the intermetallic compound containing Fe is 0.07~
If it is in the range of IJLm, sufficient heat resistance will be exhibited.

Next, hot compression molding of the powder itself can be carried out according to a conventional method, but the temperature is preferably 400°C or less. From the viewpoint of moldability, the higher the processing temperature, the better. However, Ni, C0. Cr, Zr, V, Ce, W, Ti, M
Although the addition of o thermally stabilizes intermetallic compounds containing Fe and prevents them from becoming coarse, processing temperatures exceeding 400°C may cause the intermetallic compounds to coarsen, resulting in a decrease in strength and heat resistance. be. Further, it is preferable that the molded material processed at high temperature is rapidly cooled by water quenching or the like immediately after processing.This increases the amount of solid solution of Zn, Mn, and Cu, thereby further improving the strength.

(Example) Next, the present invention will be explained in more detail based on examples.

Example Aluminum alloy (N0.1) having the composition shown in Table 1
~N0.20) were each made into a molten metal by a conventional method, and from this molten metal, an average particle size of 70 JL was obtained by Ar gas atomization method.
m powder was produced. The cooling rate in this atomization was 10 to 104°C/sec. Each of the obtained alloy powders was cold preformed (compressed to a density ratio of 80%, diameter 100 mm, length 1
20mm) + aluminum can enclosure → high temperature vacuum degassing (3
A billet with a diameter of 80 mm and a length of 150 mm was produced by the steps of 00°C) → hot press molding (up to true density) → external grinding and dislocation, and this was extruded at 300°C to make an extruded rod with a diameter of 30 mm. .

For each of the alloy extruded materials obtained as described above, a tensile test was performed at room temperature and 300° C. (holding time: 100 hr), and the average size of the intermetallic compound containing Fe was measured. The results are shown in Table 2.

Note that the average size of the intermetallic compound containing Fe was determined as follows. That is, the structure of each extruded material is observed using a transmission electron microscope, and the size of the compound is measured from a photograph of the structure using image analysis. Large number (1000 or more)
The size of the compound is measured and the size is averaged to obtain the average size of the compound.

As is clear from the results in Table 2, aluminum alloys (N0.1 to N0.17) produced by the method of the present invention! Comparative examples used in the ultra-rapid solidification method (N0.18 to N0
．． 20) Superior in both room temperature and high temperature strength compared to 4m.

(Effects of the Invention) According to the present invention, heat-resistant aluminum suitable for materials such as engine parts, turbine impellers, and aircraft parts that require heat-resistant strength (high-temperature strength) can be produced by the gas atomization method without using the ultra-rapid solidification method. Alloys can be obtained. Furthermore, the aluminum alloy rapidly solidified material according to the present invention is not only easy to manufacture, but also can be used as is for compression molding since it is obtained as an atomized powder, which has a remarkable effect on mass production and cost reduction of the above-mentioned material.

Claims (2)

[Claims] (1) Contains Fe5.0-15%, Zn0.1-5%,
and Ni0.5-15%, Co0.5-15%, Cr
0.7-15%, Zr0.3-10%, V0.3-10
%, Ce0.5-10%, W0.2-8%, Ti0.5
-10%, Mo0.2-10%, Mn0.5-15% and Cu0.2-10%, containing one or more types,
F
The average size of intermetallic compounds containing e is 0.07 to 1 μm
A heat-resistant aluminum alloy material characterized by: (2) Contains Fe5.0-15%, Zn0.1-5%,
and Ni0.5-15%, Co0.5-15%, Cr
0.7-15%, Zr0.3-10%, V0.3-10
%, Ce0.5-10%, W0.2-8%, Ti0.5
-10%, Mo0.2-10%, Mn0.5-15% and Cu0.2-10%, containing one or more types,
Al in which the total amount of added elements is 25% or less (herein, % indicates weight %), and the balance is Al and unavoidable impurities.
The molten alloy is rapidly solidified by gas atomization to form a powder, which is then hot compression molded. A method for producing a heat-resistant aluminum alloy material having a thickness of 0.07 to 1 μm.