JPH06293932A - High strength heat resistant aluminum-base alloy and its production - Google Patents

Abstract

PURPOSE:To produce a high strength heat resistant Al-base alloy having high temp. strength higher than that of the conventional Al-base alloy. CONSTITUTION:This alloy consists of a matrix phase, which has a composition represented by the general formula AlaNibCod(wherein in 50=<=a<=95 atomic %, 0.5<=b<=35 atomic %, 0.5<=c<=15 atomic %, and 0.5<=d<=10 atomic %) and is composed of fine crystalline substances, and fine grains to be dispersed, which are dispersed into the matrix phase and composed of AlNiY intermetallic compound or AlNiYCo intermetallic compound. A rapidly solidified Al-base alloy is optimized as fine crystalline substance, and, by applying hot plastic working to the rapidly solidified Al-base alloy, proper amounts of fine grains to be dispersed with high thermal stability are precipitated and dispersed in optimum shape into the matrix phase of fine crystalline substance and, as a result, deformation in the matrix phase at high temp. can be sufficiently prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high strength heat resistant aluminum base alloy excellent in high hardness, high strength, high wear resistance and high heat resistance, and particularly to a high strength heat resistant aluminum base alloy excellent in high temperature strength and its It relates to a manufacturing method.

[0002]

2. Description of the Related Art Amorphous alloys, that is, amorphous alloys are defined as those in which the arrangement of the atoms that make up a substance does not have the long-period regularity as in crystalline alloys, and are generally used for rapid cooling and electrodeposition of molten alloys. , Vapor deposition, sputtering and the like. It is known that this amorphous alloy has various excellent properties in terms of material properties as compared with the corresponding crystalline alloy.

Even in aluminum (Al) based alloys,
It is conventionally known that an amorphous alloy can be obtained, and as a metal-metal amorphous alloy, an Al-Ln binary alloy (Ln = Y, La, Pr, Nd, Sm, Eu, Gd, T) is used.
b, Dy, Ho, Er, Tm, Yb), or Al-
Ln-TM ternary alloy (TM = V, Nb, Mo, Mn, F
e, Co, Ni) and the like.

The hardness (Hv) and the tensile strength (σf) of the ultra-quenched amorphous ribbon of Al-Ln binary alloy increase with the increase of the amount of Ln. The maximum value of hardness is 250 Hv and the tensile strength is 875 MPa. Furthermore, high mechanical strength is obtained in the Al-Ln-TM ternary amorphous alloy, and hardness is 340 Hv and tensile strength is 1140 MPa in the Al-Ln-Ni system.
Therefore, these values are much higher than the maximum value (180 Hv, 550 MPa) of the practical Al-based crystalline alloy,
It can be seen that the Al-based amorphous alloy has excellent mechanical properties.

Further, in Japanese Patent Laid-Open No. 1-275732, a general formula Al _a M _b X _c (where M = V, Cr, M
n, Fe, Co, Ni, Cu, Zr, Ti, Mo, W,
One or more metal elements selected from Ca, Li, Mg, Si and Nb, X = Y, La, Ce, Sm, N
One or more metal elements selected from b, Hf, Ta, and Mm (mesh metal), a, b, and c are atomic percentages of 50 ≦ a ≦ 95, 0.5 ≦ b ≦ 35, 0.5.
≦ c ≦ 25) by rapid solidification of a ternary alloy having a tensile strength of 87 to 103 kgf / mm ² and a yield strength of 8
2-96 kgf / mm ² of amorphous, a composite of amorphous and fine crystalline, or fine crystalline is obtained. Such Al
An amorphous alloy composed of a base, a composite alloy of amorphous and microcrystalline, or a microcrystalline alloy has a hardness and a tensile strength that are at least twice as high as those of a conventional Al-based crystalline alloy. ing.

[0006]

However, as is clear from Table 1, the strength of conventional Al alloys is remarkably reduced at a high temperature of 300 ° C.
Stop showing a.

[0007]

[Table 1]

Therefore, in order to reduce the weight of aircrafts and automobiles, the advent of high heat-resistant Al-based alloys having higher high temperature strength has been desired. The present invention has been made in view of the above-mentioned problem that the high temperature strength of the conventional Al-based alloy is insufficient, and a high-strength heat-resistant Al-based alloy that maintains a higher high-temperature strength than the conventional Al-based alloy. It is also an object to provide an alloy.

[0009]

The present inventor has found that Al--Ni
It was studied to improve the high temperature strength by optimizing the microstructure by adding other elements in the -Y alloy. As a result, the high temperature strength of the conventional Al-based alloy remains at the above-mentioned level because the intermetallic compound having high thermal stability is insufficiently dispersed and the conventional intermetallic compound is It was discovered that it was not enough to suppress the deformation.
Further, Co is adopted as an additional element, and AlNiY intermetallic compound or AlNi which has high thermal stability in the fine crystalline material.
It has been discovered that high temperature strength can be obtained by dispersing the YCo intermetallic compound. And an appropriate amount of AlNi
Ni, Y, C in which a Y intermetallic compound or AlNiYCo intermetallic compound forms a fine structure in an optimal shape and dispersion state
As a result of repeated research on the appropriate content range of o, high strength heat resistance A with higher high temperature strength than conventional Al-based alloys
The l-based alloy was completed.

That is, the high-strength heat-resistant Al-based alloy of the present invention has the general formula Al _a Ni _b Y _c Co _d (where atomic percent is 50 ≦ a ≦ 95, 0.5 ≦ b ≦ 35, 0.5 ≦ c
≦ 15, 0.5 ≦ d ≦ 10), and has a fine crystalline matrix phase and AlN dispersed in the matrix phase.
iY intermetallic compound or AlNiYCo intermetallic compound dispersed particles.

In the high-strength heat-resistant Al-based alloy of the present invention, the dispersed fine particles have a long side length of 1 μm or less and an aspect ratio (long side length: short side length) of 1.5 or more. It can be needle-shaped or plate-shaped. General formula Al _a Ni _b Y _c
In Co _d , in atomic percent 50 ≦ a ≦ 95,
The reason for limiting each to 0.5 ≦ b ≦ 35 is that it is difficult to form a non-equilibrium phase outside this range. Further, in the general formula Al _a Ni _b Y _c Co _d , the atomic percentages are limited to 0.5 ≦ c ≦ 15 and 0.5 ≦ d ≦ 10, respectively.
iY intermetallic compound or AlNiYCo intermetallic compound cannot be obtained, and AlNiY intermetallic compound or Al on the high concentration side.
This is because the NiYCo intermetallic compound becomes coarse and an optimum precipitation / dispersion state cannot be obtained.

The dispersed fine particles are limited to those having a long side length of 1 μm or less and an aspect ratio of 1.5 or more, which are needle-like or plate-like. This is because it can be obtained. In addition, the method for producing a high-strength heat-resistant Al-based alloy of the present invention is based on the general formula Al _a Ni _b Y _c Co
_d (provided that atomic percentage is 50 ≦ a ≦ 95, 0.5 ≦
b ≦ 35, 0.5 ≦ c ≦ 15, 0.5 ≦ d ≦ 10), a rapidly solidified Al-based alloy is subjected to hot plastic working, and AlNiY metal It is characterized in that dispersed fine particles composed of a compound or AlNiYCo intermetallic compound are deposited and dispersed.

The rapidly solidified Al-based alloy is obtained by rapidly solidifying a molten alloy having the above composition by a liquid rapid solidification method. The liquid rapid solidification method is a method of rapidly cooling and supercooling a molten metal / alloy and freezing its structure to obtain an amorphous material. A gun method and a piston-anvil method for obtaining a thin piece of about several hundreds of mg. Alternatively, there are a centrifugal method capable of continuously obtaining a ribbon, a single roll method, a twin roll method, a spray method capable of obtaining a powder, and a rotating submerged spinning method obtainable as a fine wire.

The single roll method, the twin roll method, the rotating submerged spinning method and the high pressure molten metal spraying method are particularly effective for the present invention. With these methods, a cooling rate of about 10 ² to 10 ⁶ ° C / sec can be obtained. To produce a thin strip by the single roll method or the twin roll method, the molten metal is jetted through a nozzle hole and onto a copper or steel roll having a diameter of 30 to 300 mm which is rotating at a constant speed of about 300 to 10000 rpm. To do. This makes it possible to produce amorphous flakes having a width of about 1 to 300 mm and a thickness of about 5 to 500 μm. In order to obtain an amorphous fine wire by a spinning liquid spinning method, a depth of 1 to 10 held by a centrifugal force in a drum rotating at about 50 to 500 rpm is used.
cm cooling liquid layer is formed, and in this rotating cooling liquid layer,
Molten metal is jetted through a nozzle hole with a back pressure of argon.
In order to obtain a rapidly solidified powder by the high pressure molten metal spraying method, 40-100 kgf / cm ² of high pressure nitrogen is added to the dropped molten metal,
The molten metal is rapidly cooled and solidified by blowing argon gas or helium gas. Whether or not the rapidly solidified Al-based alloy is fine crystalline can be known by a usual X-ray diffraction method. That is, the presence of fine crystalline material indicates a synthesized diffraction pattern of diffraction peaks due to the fine crystalline material.

As means for subjecting the rapidly solidified Al-based alloy to hot plastic working, extrusion, press working, or hot forging can be adopted. The structure of the rapidly solidified Al-based alloy may include an amorphous phase in addition to the fine crystalline material.
Further, it may be an amorphous phase or a single phase. The amorphous phase changes into fine crystalline by hot composition processing at a crystallization temperature or higher.

[0016]

In the high strength heat resistant Al-based alloy of the present invention, Al, N
The optimum content range of i, Y, and Co optimizes the rapidly solidified Al-based alloy as fine crystalline. In other words, when the parent phase is an amorphous phase, it is crystallized by the phase transformation above the crystallization temperature and the strength is reduced, but in the case of fine crystalline, there is no such phase transformation, so at high temperature High thermal stability.
Then, by subjecting the rapidly solidified Al-based alloy to hot plastic working, AlNi having high thermal stability is formed in the microcrystalline matrix phase.
Dispersed fine particles composed of Y intermetallic compound or AlNiYCo intermetallic compound are deposited and dispersed in an appropriate amount and in an optimum shape,
Since these dispersed fine particles sufficiently suppress the deformation in the matrix at high temperature, high high temperature strength can be obtained.

[0017]

EXAMPLES Examples of the present invention will be described below together with comparative examples.

[0018]

[Table 2]

Al alloys having chemical components shown in Table 2 were melted by arc melting to prepare a mother alloy. After melting the mother alloy in a high frequency furnace under an argon gas atmosphere, a non-equilibrium phase powder (amorphous single phase) powder was produced by a high pressure molten metal spraying method under the condition of a helium gas pressure of 100 kgf / cm ² . And
The powder classified to 25 μm or less has a temperature of 500 ° C. and a pressing force of 5
It was extruded at an extrusion ratio of 10: 1 at 00 to 1000 MPa to obtain a columnar material having a diameter of 7 mm and a length of 200 mm. The columnar material obtained by extrusion had a true density.

TEM (tra
nsmisson electron microsc
As a result of carrying out observation, in addition to fcc (face centered cubic lattice) Al and YAl ₃ ,
It was confirmed that the acicular intermetallic compounds of AlNiY and AlNiYCo were dispersed with the long side of 1 μm or less and the aspect ratio of 1.5 or more. On the other hand, in Comparative Examples 6 to 8, fccA
1 and YAl ₃ and Ni ₃ Al were observed, but AlNi
No acicular intermetallic compounds of Y and AlNiYCo were observed.

Next, the tensile test of the columnar material was conducted by using an Instron type tester with a tensile test piece prepared from the columnar material. The results obtained are also shown in Table 2. Also, Al _88.5 Ni
_A tensile test piece was similarly prepared from an Al alloy having a composition of ₈ Mm _3.5 and used as Comparative Example 9. The relationship between the temperature (° C.) and the tensile strength σf (MPa) for Example 1 and Comparative Examples 6, 7, and 9. Is also shown in FIG. Note that Mm in Comparative Example 9 represents misch metal. The main elements of misch metal are La and Ce
In addition to the above, rare earth (lanthanoid series) elements other than La and Ce and unavoidable impurities (Si, Mg,
Fe, Ag, etc.) is a common name for a complex containing the components of Ce45 to 54 wt%, La23 to 32 wt%, and Nd1.
3 to 19 wt%, Pr3 to 8 wt%, Fe less than 1%, and other less than 1 wt%.

In Comparative Examples 6, 7, and 9, the tensile strength at 300 ° C. was 350 MPa or less. On the other hand, in Examples 1 to 5, high high temperature strength of 410 MPa or more at 300 ° C. was shown, and the effect of the present invention could be confirmed.

[0023]

As described in detail above, the high-strength heat-resistant aluminum-based alloy of the present invention can exhibit higher high-temperature strength than conventional Al-based alloys. Therefore, by adopting the high-strength heat-resistant aluminum-based alloy of the present invention, it is possible to meet the demands of aircrafts and automobiles that are being reduced in weight.

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between temperature and tensile strength for Example 1 and Comparative Examples 6, 7, and 9.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akira Kato 2-36-1, Yagiyamamotomachi, Taihaku-ku, Sendai City, Miyagi Prefecture 26-3 Success 26 B101 (72) Ken Ken Masumoto 3-8-22, Uesugi, Aoba-ku, Sendai City, Miyagi Prefecture No. (72) Inventor Akihisa Inoue Kawauchi Muzen, Aoba-ku, Sendai-shi, Miyagi Kawauchi Housing 11-806 (72) Hidehiko Horikiri 2-255 Yonegabukuro, Aoba-ku, Sendai-shi, Miyagi

Claims (3)

[Claims] 1. A general formula Al _a Ni _b Y _c Co _d (provided that atomic percentage is 50 ≦ a ≦ 95, 0.5 ≦ b ≦ 35,
0.5 ≦ c ≦ 15, 0.5 ≦ d ≦ 10) and a matrix phase composed of a fine crystalline material, and an AlNiY intermetallic compound or Al dispersed in the matrix phase.
A high-strength heat-resistant aluminum-based alloy, characterized by comprising dispersed fine particles of NiYCo intermetallic compound. 2. The dispersed fine particles have long sides of 1 μm or less,
The high-strength heat-resistant aluminum-based alloy according to claim 1, which has an aspect ratio of 1.5 or more and is needle-shaped or plate-shaped. 3. A general formula Al _a Ni _b Y _c Co _d (provided that atomic percentage is 50 ≦ a ≦ 95, 0.5 ≦ b ≦ 35,
0.5 ≦ c ≦ 15, 0.5 ≦ d ≦ 10), a rapidly solidified aluminum-based alloy is subjected to hot plastic working,
A method for producing a high-strength heat-resistant aluminum-based alloy, which comprises depositing and dispersing dispersed fine particles of an AlNiY intermetallic compound or an AlNiYCo intermetallic compound in a matrix of fine crystalline material.