JPH01316433A - 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, Mg, 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% Mg and one or more kinds among 0.5-15% Ni, 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, 1.5-15% Mn and 0.1-5% Zn, 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 sooidification by a gas atomizing method to form powder and is subjected to hot compacting by an ordinary method. The average size of an intermetallic 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.
018.2218.4032 etc.) is also 200°
At temperatures above C, 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 A1-8
Fe-4Ce, An-8Fe-2M0. Al1-8Fe
Alloys such as -2Go have been provided.

The manufacturing process using powder metallurgy for aluminum alloys involves rapid solidification of a molten alloy using the atomization method, twin roll method, spray roll method, etc. to form a powder, ribbon, or flake shape, which is then cold-opened. The density ratio (
After sealing the compact with a powder density of 70% or more (ratio to true density),
After vacuum degassing treatment, the density ratio is reduced by hot processing.
% billet, and then extrusion, forging, etc. are generally used in order to increase the bonding strength between the particles.

(Problem to be solved by the invention) However, the above AU-8Fe-4Ce, Aft-8F
e-2M0. Alloys such as An-8Fe-2Co are easy to manufacture because they exhibit excellent heat resistance only when the molten metal is ultra-rapidly solidified at 105°C/sec or higher and then compression molded. Large and inexpensive gas atomized powder (cooling rate 10-105°C/5ec)
However, there was a problem in 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 10"C/sec or higher include the quench roll method and melt spinning method, but all of them require special manufacturing equipment and solidification technology, resulting in increased costs. Furthermore, 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. There was a problem that the cost was high.

Accordingly, 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) In order to solve the above problems, the present inventors conducted intensive research and found a specific aluminum alloy! The inventors have discovered that the above object can be achieved by forming a gas atomized powder using a molten metal of the same composition, and have completed the present invention based on this knowledge.

That is, 1 the present invention includes (1) Fe 5.5 to 15% by weight (hereinafter simply referred to as %), Mg 0.1 to 5%, and Ni0
．． 5-15%, Co 0.5-15X, Cr 0.
7-15%, Zr0.3-10%, V0.3-10%,
Ce 0.5-10%, W 0.2-8%, Ti 0
．． 5-10%, Mo 0. '2-10%.

1 of Mnl', 5-15% and Zn 0.1-5%
Contains one or more species, the total amount of added elements is 25% or less, and the remainder is A! ;L and unavoidable impurities, F
The average size of intermetallic compounds containing e is 0.07 to lJL
and (2) containing 5.5-15% Fe, 0.1-5% Mg, 0.5-15% Ni, and 0.5% Co.
F15%, Cr0.7-15%, Zr0.3-10%
, V 0. :1~10%, Ce 0.5~10%,
W0.2-8%, T i 0.5-10%,
M o 0.2-10%, M n 1.5-15%
, A1 alloy molten metal containing one or more of 0.1 to 5% of Zn, the total amount of added elements being 25% or less, and the remainder containing AJI and unavoidable impurities, by gas atomization method. A powder having the above composition characterized in that it is rapidly solidified to form a powder and then hot compression molded, and the average size of the intermetallic compound containing Fe is 0.0.
The present invention provides a method for producing #thermal aluminum alloy material having a thickness of 7 to 1 μm.

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 5.5-15%. 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 5.5%, and when the Fe content exceeds 15%, not only does the degree of this effect become saturated, but the intermetallic compound becomes coarse.

The Mg content is 0.1 to 5%. Mg acts as a solid solution in An to improve the strength, and a part of it precipitates finely as an intermetallic compound not containing Fe, thereby improving the room temperature strength. These effects are caused by Mg
If the content is less than 0.1%, it is not sufficient; on the other hand, if it exceeds 5%, its effect is saturated, leading to an increase in cost.

Ni, G0. Cr, Zr, V, Ce, W.

Ti and Mo have the effect of thermally stabilizing intermetallic compounds containing Fe, which increases high-temperature strengtha.
Like Mg, M n and Z n have the effect of improving the strength by being dissolved in An as a solid solution, and the effect of improving the strength by partially precipitating finely. Ni
,C,0. Cr, Zr, V.

Ce, W, Ti, M0. Mn and Zn are respectively.

Ni0.5-15%, Go 0.5-15%, Cr0.
7-15%, Zr 0.3-10%, V 0.3-10%
, Ce 0.5-10%, W 0.2-8%, Ti0
．． 5-1G%, Mo0.2-10%, Mn 1.5-1
5%, and Zn is added singly or in combination in the range of 0.1 to 5%. 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 An, 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~
Let it be lILm.

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 An 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, the use of the gas atomization method, which has established manufacturing technology and already has a mass production plant, has significant cost advantages. In addition, since the rapidly solidified material produced by the gas atomization method is in the form of particulate powder, it is difficult to handle and press, compared to ribbon-shaped thin strips, flakes, etc. produced by the rapid cooling roll method. It has the advantage of being easy to mold, and is advantageous in terms of manufacturing costs.

However, in the gas atomization method, the size of the intermetallic compound containing Fe that is finely dispersed during rapid solidification is reduced to 0.07 pm.
It is currently difficult to make it smaller. In general, the compound size in a rapidly solidified material becomes smaller as the solidification rate increases.For example, in a powder with a particle size of 5Bm or less, Fe
The size of the intermetallic compound containing
The proportion of the following powders is as low as about 2 to 3%, and classifying and using them alone would result in a significant increase in cost. Therefore, in this case, the size of the intermetallic compound containing Fe was reduced to
It is practically impossible to make the size smaller than 1Lm, but the average size of intermetallic compounds containing Fe in a molded material obtained by compression molding ordinary gas atomized powder is 0.07~lp.
It is m. The size of the intermetallic compound containing Fe is 0.07
If it is in the range of ~lILm, 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 point of view of moldability, the higher the processing temperature, the better. However, Ni, C0. Cr.

Although the addition of Zr, V, Ce, W, Ti, and Mo thermally stabilizes the intermetallic compounds containing Fe and prevents them from becoming coarse, the intermetallic compounds become coarse at processing temperatures exceeding 400°C. , strength and heat resistance may decrease. 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 Mg, Mn, and Zn, 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) was made into a molten metal using a conventional method, and the average particle size of the molten metal was 70IL by Ar gas atomization method.
m powder was produced. The cooling rate in this atomization was 10-10'C/sec.

Next, 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 (
A billet with a diameter of 80 mm and a length of 150 mm is produced by the process of hot press forming (up to true density) → external milling and dislocation (300 °C), and this is extruded at 300 °C to form a billet with a diameter of 3
It was made into an extruded rod of 0 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, the aluminum alloys (N0.1-N0.17) produced by the method of the present invention were compared to the comparative examples (N0.18-N0.17) used in the ultra-rapid solidification method.
20), it is superior in both strength at room temperature and after being kept at high temperature.

(Effects of the Invention) According to the present invention, heat-resistant aluminum, which is 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. Mu alloy can be obtained.

In addition, the rapidly solidified aluminum alloy material according to the present invention is not only easy to manufacture, but since it is obtained as an atomized powder, it can be used as it is for compression molding, and has a remarkable effect on mass production and cost reduction of the material.

Claims (2)

[Claims] (1) Contains Fe5.5-15%, Mg0.1-5%,
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%, Mn1.5~15%, and Zn0.1~5%. ) with the balance being Al and unavoidable impurities, and Fe
A heat-resistant aluminum alloy material characterized in that the average size of the intermetallic compound containing is 0.07 to 1 μm. (2) Contains Fe5.5-15%, Mg0.1-5%,
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%, Mn1.5~15%,
Contains one or more of Zn0.1 to 5%, and the total amount of added elements is 25% or less (% indicates weight%).
A molten Al alloy having the remainder Al and unavoidable impurities is rapidly solidified by gas atomization to form a powder, which is then hot compression molded. and a method for producing a heat-resistant aluminum alloy material, wherein the average size of the intermetallic compound containing Fe is 0.07 to 1 μm.