JPH05331586A - High strength aluminum alloy - Google Patents

Abstract

PURPOSE:To obtain an amorphous or fine crystalline high strength aluminum alloy having low specific gravity and high strength. CONSTITUTION:This alloy has a composition where the content of Mm to be incorporated into Al is controlled to 0.5-4 atomic % and also Fe and Ti or Mn are incorporated so that they satisfy, by atom, 1<=Fe+Ti+Mn<=8 and 0.2<=(Ti+Mn)/(Fe+Ti+Mn)<=0.7. Further, this alloy has a structure of fine crystalline substances or a mixed structure of amorphous and fine crystalline substances. Because the amounts of the addition elements having relatively high specific gravities are limited and the content of Al by atomic percentage is increased, the specific gravity of the alloy can be reduced. Moreover, amorphous phases or fine crystalline phases are uniformly and properly dispersed in fine crystalline phases in a matrix and the fine crystalline phases in the matrix are subjected to solid solution strengthening by means of Mm and transition metals, such as Ti, Mn, and Fe, by which low specific gravity and high strength which cannot be provided by the conventional alloy can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-strength aluminum alloy having fine crystalline or amorphous phase dispersed therein.

[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 a crystal-like long-period regularity.
It is manufactured by a manufacturing method such as vapor deposition and sputtering. It is well known that this amorphous alloy has various excellent properties in terms of material properties as compared with the corresponding crystalline alloy.

It has been well known that an amorphous alloy can be obtained even from an Al-based alloy. As a metal-metal non-binding alloy, an Al-Ln binary alloy (Ln = Y, L) is used.
a, Ce, Pr, Nd, Sm, Eu, Gd, Tb, D
y, Ho, Er, Tm, Yb), or Al-Ln-
TM ternary alloy (TM = V, Nb, Mo, Mn, Fe, C
o, Ni), etc.

The hardness (Hv) and the tensile strength (σf) of the Al-Ln binary alloy increase as the amount of Ln increases, and the maximum value of Hv and σf in the binary amorphous alloy is 250 and 875
It is MPa. Higher mechanical strength is Al-Ln-T
Al-Ln- was obtained in the M3 element amorphous alloy.
In Ni system, the maximum values of σf and Hv are respectively 1140
These values are MPa and 340, which are much higher than the maximum values (550 MPa, 180) of the Al-based crystalline alloy, and it can be seen that the Al-based amorphous alloy has excellent mechanical properties.

Further, in Japanese Patent Application Laid-Open No. 1-275732, the general formula: Al _a M _b X _c (where M: V, C
r, Mn, Fe, Co, Ni, Cu, Zr, Ti, M
1 selected from o, W, Ca, Li, Mg, Si, Nb
Or two or more metal elements, X: Y, La, Ce,
One or more metal elements selected from Sm, Nd, Hf, Ta, Mm (Misch metal), a, b, c
Is an atomic percentage, a: 50 to 95 at%, b: 0.
5 to 35 at%, c: 0.5 to 25 at%) 3
Tensile strength 87-10 by quenching and solidifying the original alloy
3 kg / mm ^2, a complex of amorphous or amorphous and fine crystalline yield strength 82~96kg / mm ² is obtained.

As described above, excellent mechanical strength can be obtained in the Al-Ln-Ni ternary amorphous alloy. However, the basic composition is Al ₈₈ Ni ₁₀ Y ₂ alloy,
Studies have been conducted on a quaternary alloy in which a part of Ni is replaced with Mn, Fe, Co, Zr, etc., and it is as high as 1400 MPa in the Al ₈₈ Ni ₅ Y ₂ Fe ₅ alloy and 1470 MPa in the Al ₈₈ Ni ₈ Y ₂ Mn ₂ alloy. Tensile strength is obtained (Japan Society for the Promotion of Science, Amorphous Materials, 147th Committee, 3rd Committee)
0th research material).

[0007]

As described above, an Al-based amorphous alloy or an alloy composed of a composite of an amorphous and a fine crystalline material has a tensile strength more than twice that of a conventional Al crystalline alloy. Although having the hardness or hardness is as described above, the specific gravity and the tensile strength are as shown in Table 1 when compared with other crystalline or amorphous alloys.

[0008]

[Table 1]

As is clear from Table 1, among the amorphous Al alloys, the specific gravity is Al ₈₈ which is the strongest quaternary alloy.
3.2 in Ni ₈ Y ₂ Mn ₂ alloy, Al ₈₈ Fe ₉ Mm ₃
In alloy, it is as large as 3.3. On the other hand, the specific gravity of the current crystalline forged material / extruded material is as small as 2.8 to 2.9, but the strength is as small as 700 MPa at the maximum.

The reason why the conventional amorphous alloy has a heavy specific gravity is that it contains Fe, Ni, Mn, etc., which have a higher specific gravity than Al. Therefore, weight reduction of aircraft and automobiles,
In order to reduce fuel consumption, it has been desired to develop an Al-based amorphous alloy having a lower specific gravity and a high strength.

The present invention has been made in view of the above-mentioned problem that the specific gravity of the Al-based amorphous alloy is large, and maintains the high strength with a lower specific gravity than the conventional Al-based amorphous alloy. The present invention aims to provide the Al-based amorphous alloy described above.

[0012]

[Means for Solving the Problems] In order to reduce the specific gravity,
The idea was to increase the atomic percentage of Al in the Al-Ln-TM system as much as possible. On the other hand, by adding various kinds of Ln and TM to the minimum, the amorphous forming ability of the alloy was maintained, and by optimizing the structure, high strength was maintained, and practicality such as cost was examined.

As a result, TM is Ti, Mn, Fe.
And Lm was selected as Mm. Further, considering that high strength can be obtained by dispersing the fine crystalline phase in the amorphous phase, an appropriate amount of the amorphous phase or the fine crystalline phase is dispersed and the matrix structure is optimally solid-solution strengthened. As a result of repeated research on appropriate content ranges of Ti, Mn, Fe, and Mm that have different crystal phases, an Al-based amorphous alloy having lower specific gravity and higher strength than the conventional Al amorphous alloy was completed. ..

The high strength aluminum alloy of the present invention is Fe
And one or two of Ti and Mn, and Mm (where Mm is misch metal), the balance consisting of unavoidable impurities and Al, the respective amounts being in atomic%, and the following relational expression 1 ≦ Fe + Ti + Mn ≦ 8 0.2 ≦ (Ti + Mn) / (Fe + Ti + Mn) ≦ 0.
7 The condition is that 0.5 ≦ Mm ≦ 4 is satisfied, and a fine crystalline structure or a mixed structure of fine crystalline and amorphous is provided.

Mm represents a misch metal, and the main elements of the misch metal are La and Ce. In addition to the above La and Ce, rare earth (lanthanoid series) elements and inevitable impurities (Si, Mg, Fe, Ag, etc.) Is a common name for a composite containing, and the component is Ce45 to 54 wt%,
La23 to 32 wt%, Nd13 to 19 wt%, Pr3
˜8 wt%, Fe less than 1% and other less than 1 wt%.

In the high-strength aluminum alloy of the present invention, in order to obtain a mixed phase of amorphous and fine crystalline or fine crystalline, a molten alloy of the above composition is rapidly solidified 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.
Gun method for obtaining thin slices, piston-anvil method, or centrifugal method for continuously obtaining thin strips, single-roll method, twin-roll method, spray method for obtaining powder, rotating liquid for obtaining fine wire There is a spinning method.

The single roll method, the twin roll method or the rotating submerged spinning method is particularly effective for the present invention. By these methods, a cooling rate of about 10 ⁴ to 10 ⁶ ° C / sec can be obtained. In order to produce a thin strip by the single roll method or the twin roll method, the molten metal is jetted to 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 through a nozzle hole. .. This results in a width of about 1
Amorphous flakes with a thickness of 300 mm of about 5 to 500 μm can be produced.

In order to obtain an amorphous fine wire by the rotating submerged spinning method, a cooling liquid layer having a depth of 1 to 10 cm held by centrifugal force is formed in a drum rotating at about 50 to 500 rpm, and this rotation is performed. It is obtained by jetting the molten metal through the nozzle hole into the cooling liquid layer under a back pressure of argon.

In order to obtain an amorphous powder by the high-pressure molten metal spraying method, a high-pressure nitrogen or argon gas or a helium gas of 40 to 100 kgf / cm ² is blown onto the dropped molten metal to quench the molten metal. Be done. In addition, in order to obtain the amorphous phase or the fine crystalline phase, a vacuum vapor deposition method, a sputtering method, a vapor phase chemical reaction method (CVD method) or the like can be used in addition to the liquid rapid solidification method.

Whether the aluminum alloy obtained by the liquid rapid solidification method or the like is a mixed phase of amorphous and fine crystalline or fine crystalline can be known by a usual X-ray diffraction method. That is, the presence of amorphous material shows a halo pattern peculiar to an amorphous structure, and in the case of a composite of amorphous and fine crystalline material, a diffraction peak due to the halo pattern and fine crystalline material was synthesized. The diffraction pattern is shown.

Amorphous alloys have a differential scanning calorimeter (DS).
In C), it is detected as a heating at the crystallization temperature (T _X) or higher.

[0022]

The high-strength aluminum alloy of the present invention has a total content of Fe, Ti and Mn as additive elements of 8 atomic% or less,
Further, since Mm is 4 atomic% or less, the content of Al having a low specific gravity is large, the specific gravity of the alloy can be suppressed to 3.0 or less, and the specific strength can be improved.

Further, since Mm, Ti, Mn, and Fe were selected from the lanthanoid series element and the transition metal element forming the Al amorphous alloy, and their contents were regulated according to the above relational expressions, they were amorphous. The fine phase or fine crystals are dispersed in the fine crystalline phase to a suitable degree, and the resulting fine crystalline phase of the matrix is solid-solution strengthened by Mm and the transition metal, resulting in low specific gravity and high strength that cannot be obtained with conventional alloys. was gotten.

Next, the reason why the component range is limited in the present invention will be explained. 1 ≦ (Fe + Ti + Mn) ≦ 8% If Fe + Ti + Mn is less than 1%, the amount of solid solution is small and solid solution strengthening is not performed, and there is no strengthening by Ti and Mn. On the other hand, if it exceeds 8%, there is strengthening by Ti and Mn, but the specific gravity increases and the specific strength decreases, so the content of Fe + Ti + Mn was limited to 1-8%.

0.2 ≦ (Ti + Mn) / (Fe + Ti +
Mn) ≦ 0.7 Ti or Mn promotes solid solution strengthening due to the interaction with Fe, and improves the strength of the Al alloy by promoting the refinement of the crystal phase. The details of its action are not clear yet, but according to the experiment, (Ti + Mn) in atomic%
If / (Fe + Ti + Mn) is less than 0.2, the strength is not sufficiently improved, and if it exceeds 0.7, the strength improving effect is saturated, so the ratio is limited to 0.2 to 0.7. ..

0.5 ≦ Mm ≦ 4 If the Mm content is less than 0.5%, the solid solution strengthening of Mm and the ability to form an amorphous phase are not exhibited, and the strength is low. On the other hand, if it exceeds 4%, solid solution strengthening and amorphous forming ability are sufficient, but specific gravity increases and specific strength decreases. Therefore, the Mm content is limited to 0.5 to 4%.

[0027]

EXAMPLES Examples of the present invention will be described together with comparative examples to clarify the effects of the present invention. A button ingot was produced by melting the Al alloy having the chemical composition shown in Table 2 by plasma melting. In addition, No. 1 to 12 are examples of the present invention. No. Nos. 13 to 19 are comparative examples outside the composition range of the present invention, but No. Nos. 13 and 14 are JP-A-1-275732
Corresponding to the components disclosed in No. 15, Mm is less than 0.5%, Fe + Ti + Mn is less than 1%, N
o. No. 16 has Mm of 4% or more, Fe + Ti + Mn of 8% or more, and No. No. 17 is a comparative example in which Mm is 4% or more and Fe + Ti + Mn is less than 1%. In addition, No. 18 is (Ti +
Comparative example in which Mn) / (Fe + Ti + Mn) is 0.7 or more,
No. 19 is a comparative example in which (Ti + Mn) / (Fe + Ti + Mn) is 0.2 or less.

[0028]

[Table 2]

The ingot cut out from this button ingot is put into the quartz tube 1 of the single roll type liquid rapid solidification apparatus shown in FIG. 1, and a small hole 5 (hole diameter:
(0.3 mm) is installed directly above the copper roll 5 with a gap of 0.5 mm, the ingot in the quartz tube 1 is melted by high frequency, and then a jet pressure of 1 kgf / is applied to the copper roll 5 rotating at 4000 rpm. The molten metal 3 was sprayed in cm ² , and rapidly solidified to obtain a ribbon 4 having a width of about 1 mm and a thickness of about 20 μm.

As a result of carrying out X-ray diffraction on the obtained ribbon, all diffraction peaks were αAl and there was no intermetallic compound. Moreover, as a result of performing the differential thermal analysis, No. 1
Since ~ 6 had no exothermic reaction, it was found to be crystalline. In addition, No. 7 to 12 all had an endothermic reaction, the presence of an amorphous phase was confirmed, and it was confirmed that it was a mixed phase of amorphous and crystalline. Next, a ribbon tensile test was performed using an Instron tensile tester. The results obtained are summarized in Table 3.

[0031]

[Table 3]

As shown in Table 3, no.
No. 13 has a large specific gravity because Fe + Ti + Mn is 8% or more, and has a low specific strength because it does not contain Ti or Mn. In addition, No. No. 14 contained 10% of Mm and had high strength, but had low specific strength. No. No. 15 had an Mm of less than 0.5% and Fe + Ti + Mn of less than 1%, so the strength was extremely low. 16 has a Mm of 4%
As described above, since Fe + Ti + Mn is 8% or more, the strength is high, but the specific gravity is large and the specific strength is low. 17
Since Mm was 4% or more and Fe + Ti + Mn was less than 1%, solid solution strengthening was insufficient and strength was poor.
In addition, No. 18 is (Ti + Mn) / (Fe + Ti + M
n) is 0.7 or more, and No. 19 is (Ti + Mn)
Since / (Fe + Ti + Mn) was 0.2 or less, the tensile strength was low at 820 to 880 MPa, and the specific strength was low.

On the other hand, No. 1 which is an embodiment of the present invention.
1 to 12 have a small specific gravity of 2.75 to 3.04 and a large tensile strength of 1000 to 1200 MPa, and as a result, a specific strength of 329 to 401 MPa, confirming the effect of the present invention.

[0034]

As described above, the high-strength aluminum alloy of the present invention has a Mm content of Al of 0.1% by atom.
It is regulated to 5 to 4%, and Fe and Ti or Mn in atomic% are 1 ≦ Fe + Ti + Mn ≦ 8 and 0.2 ≦ (Ti
+ Mn) / (Fe + Ti + Mn) ≦ 0.7, and is characterized by having a fine crystalline structure or a mixed structure of fine crystalline and amorphous and having a relatively large specific gravity. Since the amount of elements was regulated and the atomic percentage of Al was increased, the specific gravity of the alloy could be suppressed lightly. Further, the amorphous phase or the fine crystalline phase is appropriately dispersed uniformly in the fine crystalline phase of the matrix, and the fine crystalline phase of the matrix is solid-solution strengthened by Mm and transition metals such as Ti, Mn, and Fe. , Low specific gravity and high strength, which cannot be obtained with conventional alloys.

[Brief description of drawings]

FIG. 1 is a schematic side view of a single roll type liquid rapid solidification apparatus used in Examples.

[Explanation of symbols]

 1 Quartz tube 2 Copper roll 3 Molten metal 4 Ribbon 5 Small hole

Claims (1)

[Claims] 1. Fe, one or two of Ti and Mn, and Mm (where Mm is a misch metal), the balance consisting of unavoidable impurities and Al, the respective amounts of which are atomic% The following relational expression 1 ≦ Fe + Ti + Mn ≦ 8 0.2 ≦ (Ti + Mn) / (Fe + Ti + Mn) ≦ 0.
7 High-strength aluminum alloy satisfying 0.5 ≦ Mm ≦ 4 and having a microcrystalline structure or a mixed structure of microcrystalline and amorphous