JPH05331584A - Aluminum alloy with high elasticity and high strength - Google Patents

Abstract

PURPOSE:To obtain an Al-Ln-TM ternary aluminum alloy having high strength and high elasticity. CONSTITUTION:This alloy has a composition consisting of by weight ratio, 4-14% Mm(where Mm means misch metal), <=2% Fe, and the balance Al with inevitable impurity elements and also has a structure consisting of 10-50%, by volume ratio, of either or both of intermetallic compounds, Al4Ce and Al11La3, and the balance fine crystal phase of alpha-Al. Because the alpha-Al fine crystal phase in the resulting matrix is subjected to solid-solution strengthening by means of Mm and Fe and the high elasticity intermetallic compounds, Al4Ce and Al11La3, are deposited by 10-50% by volume ratio, the aluminum alloy having high elasticity as well as high strength 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 highly elastic and high strength lanthanoid aluminum alloy.

[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.

On the other hand, according to the powder metallurgy method utilizing the rapid solidification method of aluminum alloy, Si particles can be finely dispersed even in a hypereutectic alloy, for example, in Al-Si system, and further Fe, Mn and Ni can be dispersed. And the like can be added in a large amount, the Young's modulus is as large as 10600 kgf / mm ^2, and an alloy excellent in high temperature strength can be manufactured.

[0007]

However, the rigidity and Young's modulus of the amorphous alloy are 20 to 40% smaller than the crystals of the same alloy, and about 90 MPa at the maximum.
The reason for this is that it originates from the amorphous structure, but the low elastic value of this alloy is that unstable atoms originally present in the irregular atomic arrangement undergo internal displacement due to external stress.

Further, the Al-Si type alloy produced by the powder metallurgy method using the rapidly solidified powder has a high Young's modulus because a large amount of fine Si particles are precipitated and dispersed as described above.
Low tensile strength. This is because a large amount of Si is deposited to increase the elastic modulus, but the cooling rate is low, so that solid solution strengthening of various elements is insufficient and the crystal phase is not sufficiently refined. ..

According to the present invention, the conventional amorphous alloy has a small Young's modulus, and the Al-Si alloy produced by the powder metallurgy method using a rapidly solidified powder has a large Young's modulus but lacks in strength. The present invention has been made in view of the above points, and an object thereof is to provide a high-elasticity / high-strength aluminum alloy that is excellent in strength in addition to Young's modulus.

[0010]

In order to solve the above-mentioned problems, the inventor has conducted extensive studies on the composition range, cooling conditions and mechanical strength of an Al-Ln-TM ternary amorphous alloy. As a result, select Mm as Ln,
With respect to TM, Fe was selected, and the present invention was completed by newly discovering that an Al-Ln intermetallic compound having a large elastic modulus is deposited under a constant cooling condition in a specific composition range.

The high-elasticity / high-strength aluminum alloy of the present invention has a weight ratio of Mm (where Mm is Misch metal);
4 to 14% and Fe; 2% or less, the balance consisting of Al and an impurity element, and one or two of intermetallic compounds Al ₄ Ce and Al ₁₁ La _{3 in} a volume ratio of 10
The gist of the present invention is to have a structure in which the balance is up to 50% and the balance is a fine crystalline phase of α-Al.

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-elasticity / high-strength aluminum alloy of the present invention, in order to obtain fine crystalline and Al-Ln intermetallic compound, it is obtained by quenching and solidifying a molten metal of the alloy having the above composition by a liquid rapid solidification method. Be done. 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 pieces of about g, piston-anvil method, 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 medium 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 gas such as 40 to 100 kgf / cm ² or argon gas or helium gas 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 fine crystalline is determined by the usual X
It can be known by the line 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. Further, the Al-Ln intermetallic compound can be detected by X-ray diffraction and SEM observation.
The volume percentage of the Al-Ln intermetallic compound is
Since it is observed as a round crystal in M, it is determined by its area ratio.

[0018]

In the present invention, Mm and Fe are respectively selected from the lanthanoid series elements and the transition metal elements forming the Al amorphous alloy, and the contents thereof are regulated according to the above relational expression. The crystalline phase is evenly dispersed,
Moreover, since the fine crystalline phase produced is solid solution strengthened by Mm and the transition metal, high strength not obtained by the conventional alloys was obtained.

In the alloy of the present invention, the weight ratio is Mm; 4
.About.14%, Fe; 2% or less, and by rapid solidification, the intermetallic compound Al ₄ Ce having a large elastic modulus is obtained.
And since the Al ₁₁ La ₃ could be 10-50% precipitated by volume, could be a high elasticity of the aluminum alloy with a high strength.

Next, the reason why the component range is limited in the present invention will be explained. Mm: 4 to 14% Mm strengthens the Al alloy by solid solution and forms Al and intermetallic compounds Al ₄ Ce and Al ₁₁ La ₃ to improve the elastic modulus. If the content is less than 4%, the above effect cannot be obtained, and 1
If it exceeds 4%, an amorphous phase is formed, so that the strength is improved but the elastic modulus is decreased. Therefore, the content rate is 4 to 1
Limited to 4%.

Fe: 2% or less Fe is an element necessary for solid solution strengthening the Al alloy and improving the strength, but if it is contained in excess of 2%, the amount of Al-Ln intermetallic compound decreases. Young's modulus decreases, so the upper limit is 2
%.

In the present invention, the intermetallic compound Al ₄
The precipitation amount of Ce and Al ₁₁ La ₃ is 10 to 50 by volume ratio.
% Is because if it is less than 10%, the Young's modulus is not sufficiently improved, and if it exceeds 50%, the Young's modulus is improved but the strength is lowered.

[0023]

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 1 by plasma melting. In addition, No. 1 to 3 are examples of the present invention. No. Nos. 4 to 6 are comparative examples outside the composition range of the present invention, but No. No. 4 has an Mm content of 4% or less, and No. 5
Has an Mm content of 14% or more and an Fe content of 2% or more. No. 6 has an Mm content of 14% or more.

[0024]

[Table 1]

An 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. In addition, No. For 6, the rotation speed of the copper roll is 1
It was set to 000 rpm.

As a result of X-ray diffraction of the obtained ribbon, intermetallic compounds Al ₄ Ce and Al other than α-Al were obtained.
₁₁ La ₃ was detected. Then, after measuring the volume ratio of these intermetallic compounds by SEM, the tensile test of the ribbon was performed using an Instron tensile tester, Young's modulus and tensile strength were measured, and the obtained results are summarized in Table 1. Showed.

As shown in Table 1, no.
In No. 4, since the Mm content was 4% or less, the intermetallic compound was 10% or less, and both Young's modulus and strength were low. In addition, No. In No. 5, since the Fe content was 2% or more, the intermetallic compound was 10% or less, and although the strength was large, the amorphous phase was formed and the intermetallic compound was absent, so that the Young's modulus was lowered. No. 6 had Mm of 14% or more, so the rotation speed of the copper roll was 100.
Although the rpm was set to 0 rpm, the intermetallic compound was 50% or more, and the Young's modulus was large because there were many intermetallic compounds, but the strength decreased conversely.

On the other hand, No. 1 is the embodiment of the present invention.
1-3, the volume% of the intermetallic compound is 15-35%,
Young's modulus is as high as 105 to 117 MPa and tensile strength is 7
It was found that an aluminum alloy having a high Young's modulus and a high strength of 50 to 850 MPa was obtained, and the effect of the present invention was confirmed.

[0029]

As described above, the high-elasticity / high-strength aluminum alloy of the present invention has a weight ratio of Mm of 4 to 14%.
And Fe; 2% or less, with the balance being Al and impurity elements, and the intermetallic compounds Al ₄ Ce and Al ₁₁ L
a 1 or 2 of a ₃ are contained in a volume ratio of 10 to 50%, and the balance has a structure that is a fine crystalline phase of α-Al. -A
l The fine crystalline phase is solid solution strengthened by Mm and Fe, and the intermetallic compounds Al ₄ Ce and Al with high elastic modulus
_{Since 11} La ₃ could be deposited in a volume ratio of 10 to 50%, an aluminum alloy having high strength and high elasticity could be obtained.

[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. A weight ratio of Mm (where Mm is misch metal); 4 to 14% and Fe; 2% or less, the balance being Al and impurity elements, and an intermetallic compound Al.
High elasticity and high strength, characterized by containing one or two of ₄ Ce and Al ₁₁ La _{3 in} a volume ratio of 10 to 50%, and the balance being a microcrystalline phase of α-Al. Aluminum alloy.