JPH03264637A - Aluminum alloy high damping material and its production - Google Patents

Abstract

PURPOSE:To produce an Al alloy high damping material excellent in cold workability and vibration damping property by forming an intergranular corrosion layer of specific depth to an Al alloy having a specific composition containing Mg and Si by subjecting this Al alloy to solution treatment, to heating, and to etching treatment. CONSTITUTION:An Al alloy which has a composition consisting of, by weight, 2-11% Mg, 0.3-10% Si, and the balance Al with inevitable impurities and further containing, if necessary, one or more kinds among 0.01-2.5% Mn, 0.01-1% Cu, 0.01-2.0% Cr, 0.01-0.4% Zr, 0.005-1.0% Ti, 0.0001-0.1% B, 0.05-3% Ni, and 0.01-2% V is subjected to solution treatment. Subsequently, this alloy is heated at 100-250 deg.C for >=1hr, by which potentially base precipitates are precipitated in the grain boundary. Then, etching treatment is applied to this alloy to form an intergranular corrosion layer having a depth of >= at least 20mum from the surface, and this corrosion layer is subjected, if necessary, to resin impregnation treatment. By this method, the lightweight Al alloy high damping material excellent in cold workability and having superior vibration damping property can be obtained.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an aluminum alloy vibration damping material that has excellent vibration damping properties and is used as a structural member that dislikes vibrations in audio equipment, precision equipment, automobiles, etc. It is something.

[Conventional technology]

Generally, when an object is vibrated, the amplitude increases at a certain frequency (fr) (Figure 1). This frequency is called the resonant frequency. If the amplitude at the resonance frequency is Ao, then the amplitude that is 1/2 of this energy is A. //2 (d
In B display, this is a frequency of -3 dB). If this frequency width (half width, 3dB width) is Δf, then the loss coefficient η
It is expressed by the following equation.

η-Δf/f r A material with a large value of this loss coefficient η has excellent vibration damping properties, and when an external force is removed, vibrations are damped quickly and rapidly.

The loss coefficient η of ordinary metal materials is 0.001 or less.

Conventionally, Fe-Cr has been used as a so-called vibration damping material, a metal material for structural members that dislike vibrations in audio equipment, precision equipment, automobiles, etc.
Alloys such as Mn-Cu, Zn-An, and Ni-Ti are known. Furthermore, Mg and Mg-Zr based cast materials are also known as vibration damping materials.

[Problem to be solved by the invention]

Fe-Cr series, Mn-Cu series, Zn-Affi series, N
Although alloys such as the i-Tj series have high vibration damping properties, they have a common drawback of high specific gravity, making them unsuitable when attempting to reduce the weight of equipment. On the other hand, Mg, Mg-
Zr-based cast materials also have the advantage of exhibiting high vibration damping properties and low specific gravity, but have the disadvantage that they cannot be cold worked at all.

[Means to solve the problem]

The present invention has been made based on various studies in view of the above, and has developed an aluminum alloy vibration damping material that has a low specific gravity and is easy to cold work, and a method for manufacturing the same.

That is, the invention of claim 1 provides Mg2 to 11 wt%, 5iO0
An aluminum alloy vibration damping material characterized by forming an intergranular corrosion layer with a depth of at least 20 mm from the surface on an aluminum alloy containing 3 to 10 wt% and the balance Aff and unavoidable impurities. The invention of item 2 is M
Contains g2~11wt%, Si0.3~10wt%, and the balance is A! and unavoidable impurities,
This is an aluminum alloy vibration damping material characterized by forming a resin-impregnated intergranular corrosion layer at a depth of at least 20 μm or more from the surface.

Further, the invention of claim 3 provides M g 2 to 11 wt%, Si
Contains 0.3 to 10 wt%, roughly M n 0.01 to
2.5 wt%, Cu 0.01-1 wt%, Cr 0
．． 01-2.0wt%, Zr0.01-0.4wt%,
T i 0.005~1.0wt%, B0.0001~
0.1 匈L%, N i 0.05-3i+t%, V0.
An intergranular corrosion layer with a depth of at least 20 II m or more from the surface is formed on an aluminum alloy containing one or more of the 01 to 2 wt% of the element group, the balance being Al and inevitable impurities. The invention of claim 4 is an aluminum alloy vibration damping material having Mg2-11w.
t%, S i 0.3-10wt%, and further contains M
n0.01-2.5wt%, Cu 0.01-1wt
%, Cr0.01-2.0wt%, Z r0.01-0
．． 4wt%, Ti 0.005-1.0wt%, 80
．． 0001-0.1wt%, Ni 0.05-3wt
%, V0.01 to 2 wt% of one or more of the element groups, and the remainder is Al2 and inevitable impurities, and the particles are impregnated with resin to a depth of at least 20 capes from the surface. This is an aluminum alloy vibration damping material characterized by the formation of an interfacial corrosion layer.

Furthermore, the invention of claim 5 provides that Mg2 to 11wt%, Si
Contains 0.3 to 10 wt%, the remainder is A! After solution treatment, an aluminum alloy consisting of
Heating at 0 to 250°C for 1 hour or more to precipitate potentially base precipitates at grain boundaries, followed by corrosion treatment to form an intergranular corrosion layer at least 20 depths from the surface. A method for manufacturing an aluminum alloy vibration damping material, characterized in that Mg2-11wt
After solution treatment, an aluminum alloy containing 0.3 to 10 wt% of Si and the balance AP and unavoidable impurities is heated at 100 to 250°C for more than 1 hour to form potentially base precipitation at grain boundaries. A method for producing an aluminum alloy vibration damping material, which comprises precipitating a substance and then subjecting it to corrosion treatment and resin impregnation treatment to form a resin-impregnated intergranular corrosion layer at a depth of at least 20 μm from the surface. It is.

Moreover, the invention of claim 7 provides Mg2 to 11 wt%, Si0.
3-10 wt%, and M n 0.01-2.
5 wt%, Cu 0.01-1 wt%, Cr 0.0
1-2.0 wt%, ZrO, 01-0, 4 wt%
, T i 0.005-1. kt%, B0.0OOI ~
0.1 wt%, Ni 0.05-3 wt%, V0.
01 to 2 wt% of one or more of the element groups, and the remainder is Al! , and unavoidable impurities, is subjected to solution treatment, heated at 100 to 250°C for more than 1 hour to precipitate potentially base precipitates at grain boundaries, and then subjected to corrosion treatment. A method for producing an aluminum alloy vibration damping material, which is characterized by forming an intergranular corrosion layer with a depth of at least 20 Fm from the surface, and the invention according to claim 8 provides
Contains i 0.3-10wt%, and further contains Mn0.01~
2.5 wt%, Cu 0.01-1 wt%, Cr0.
01-2.0 wt%, Z r0.01-0.4 wt%
, T i 0.005-1.0i%, 80.0001-
0.1st%, Ni0.05-3%, V0.01-2
Contains one or more of the wt% element groups,
Remainder A! After solution treatment, an aluminum alloy consisting of unavoidable impurities is heated at 100 to 250°C for 1 hour or more to precipitate potentially base precipitates at grain boundaries, followed by corrosion treatment and resin impregnation treatment. This is a method for producing an aluminum alloy vibration damping material, characterized in that a resin-impregnated intergranular corrosion layer is formed to a depth of at least 20 layers from the surface of the aluminum alloy damping material.

[Function] Damping materials are classified into dislocation type, composite phase type, ferromagnetic type, and twin type depending on their vibration damping mechanism.

The vibration damping material of the present invention differs from the above-mentioned mechanism in that it absorbs vibration energy through minute friction between the crystal grains of the intergranular corrosion layer formed on the surface, and absorbs the vibration quickly, or forms a layer on the surface. This is based on the technical idea that the grain boundary corrosion layer is impregnated with resin, and vibration energy is absorbed by the viscoelastic deformation of the resin filled in the micro voids at the grain boundaries, thereby quickly absorbing the vibration.

That is, the present invention applies to aluminum alloys that have been subjected to intergranular corrosion treatment to a depth of 201M or more from the surface, or
Aluminum alloys with intergranular corrosion layers impregnated with resin to a depth of more than μm exhibit extremely good vibration damping properties.
Furthermore, it was discovered that the specific gravity is small and cold working is easy.

As a means to preferentially corrode grain boundaries, it is possible to precipitate an intermetallic compound with a base potential that is easily corroded at the grain boundaries, or to perform corrosion treatment after making the potential near the grain boundaries less noble compared to the inside of the grains. It is effective to apply

Mg is in the β phase (/M!-Mg-based intermetallic compound
At the same time, it is added to preferentially precipitate MgzSi at grain boundaries, and preferentially dissolve MgzSi, the beta phase whose potential is less noble, by corrosion treatment. Its content is 2-11wt%
The reason for this limitation is that below 2 wt%, β phase and MgzSi do not precipitate, while above 11 wt%, β phase and MgzS do not precipitate.
Since a large amount of i precipitates not only at the grain boundaries but also within the grains,
This is because it becomes difficult to preferentially corrode grain boundaries.

St precipitates Mg2Si together with Mg, improving material strength. Further, depending on the heat treatment conditions, it is possible to preferentially precipitate M g 2S+ at grain boundaries.

When Mg234 is precipitated at grain boundaries, Mg25i, which has a less noble potential, is preferentially dissolved by the corrosion treatment, and a grain boundary corrosion layer can be formed. The reason why the content is limited to 1 to 10 wt% is that if it is less than 1 wt%, precipitation of M g zSi will not occur, and if it exceeds 104%, a large amount of M g 2Si will precipitate not only at the grain boundaries but also within the grains. This is because it becomes difficult to preferentially corrode grain boundaries.

Others Mn, CuSCr, Zr, Ti, B.

The elements Ni and (2) mainly contribute to improving the strength of the material, and also have the effect of adjusting the crystal grain size of the material and improving vibration damping properties. Below the respective lower limits, these effects will not be sufficient, while above the upper limits, coarse compounds may be formed and the ductility of the material may be inhibited.

Note that impurities such as Fe contained in normal aluminum metal are 0.
If the content is 5 wt% or less, the effects of the present invention will not be impaired. Further, Ti, B, etc., which are usually added as a refiner for the casting structure, do not particularly impair the effects of the present invention if they are 0.5 wt % or less.

Next, in the manufacturing method of the present invention, Mg2 to 11 wt%, Si
Aluminum alloy consisting of 1~10-1% of Mg and 2~11 wt% of Mg, the balance Al and unavoidable impurities, S
i 1 to 10 wt%, and further M n 0.01
~2.5 wt%, Cu 0.01~1 wt%, Cr
0.01-2.0wt%, Zr0.01-0.4wt%
, T i 0.005-1.0wt%, B0.0001
~0. ht%, Ni0.05-3wt%, V0.01-
Contains 2iyt% of one or more of the element groups, and the remainder is A! Heating aluminum alloys (plates, extrusions, pipes, forgings, castings, etc.) at 100 to 250°C for more than 1 hour after solution treatment, which contains unavoidable impurities, produces β phase and Mg2Si at grain boundaries. The purpose is to precipitate
If the heating temperature is less than 100°C or more than 250°C and the holding time is less than 1 hour, β, Mg, and Si
cannot be precipitated at grain boundaries. The most suitable condition is 1
The solution treatment should be maintained at 40-180"C for 2 hours or more. It is appropriate to carry out the solution treatment at 450-550"C for 1 hour or more. The β phase and Mg2Si are precipitated at the grain boundaries during the treatment, and even if the solution treatment conditions are slightly different, the effects of the present invention will not be significantly impaired.

The aluminum alloy subjected to grain boundary precipitation treatment in this manner is then subjected to grain boundary corrosion treatment so that the corrosion layer extends 20 mm or more from the surface. Intergranular corrosion treatment can be carried out by immersing the material in an aqueous solution of salts such as NAL, e, acids such as HFXH (l), alkalis such as NaOH, or a mixed solution thereof, or by electrolyzing by adding an anode current. In either case, the corrosion layer should be at a depth of 20 tml or more.

Aluminum alloys subjected to such intergranular corrosion treatment are
Although it exhibits excellent vibration damping properties as it is, when the intergranular corrosion layer is further impregnated with resin, the vibration damping properties are dramatically improved. Examples of resins to be impregnated include alkyd resin, nitrocellulose resin, butyral resin, polyurethane resin, polypropylene resin, polyethylene resin, epoxy resin, aminoalkyd resin, acrylic resin, polyester resin,
Vinyl acetate resin, vinyl chloride resin, silicone resin, mixed resins of these resins, and modified versions of these resins are all suitable for use, but among these, polyester resins, polypropylene resins, and polypropylene resins, which have particularly high viscoelasticity, are used.
Polyethylene resin, silicone resin, etc. exhibit the highest vibration damping properties. These resins can be spray painted, electrostatically painted, T
It is impregnated into an aluminum alloy that has been subjected to intergranular corrosion treatment by methods such as FS painting, dipping, and powder coating. At this time, it is desirable to impregnate at least until the intergranular corrosion layer is completely filled.

Generally, during vibration, the amplitude is maximum at the surface of the object, so intergranular corrosion and resin impregnation are effective if applied to the surface layer, but if the depth is less than 2 (b++n), the vibration damping property is insufficient and the control is reduced. In order to use it as a vibration material, it is necessary to form an intergranular corrosion layer with a depth of 20 mm or more or a resin-impregnated intergranular corrosion layer.

Although the aluminum alloy vibration damping material of the present invention can be cold-worked, the effects of the present invention may be particularly impaired even if cold-work is performed before intergranular corrosion treatment or resin impregnation treatment if necessary. isn't it.

〔Example〕

Example 1 An aluminum alloy ingot having the composition shown in Table 1 was hot-rolled and cold-rolled into a plate having a thickness of 2 mm.

Next, after solution treatment at 490°C for 8 hours, grain boundary precipitation treatment was performed at 150°C for 12 hours, followed by 3% NaCN+
It was immersed in a 1% HCI solution (50°C) to form intergranular corrosion layers of various depths. In addition, some of these intergranular corrosion-treated materials were impregnated with polyethylene resin by a dipping method to completely fill the intergranular voids in the intergranular corrosion layer. Thickness 2 from this
A test piece with a width of 10 mm, a width of 10 mm, and a length of 250 mm was cut out, and its vibration damping property (loss coefficient η) was evaluated using a cantilever vibration method.

That is, one end of the test piece is chunked, an oscillator is used to forcibly apply random vibrations, and the resulting vibrations of the test piece are detected. The input-output amplitude ratio (frequency response function) in the frequency domain is determined from this input vibration and the detected (output) vibration using a 2-channel fast Fourier transform analyzer (2ch, FFT). The resonance frequency (fr) showing the maximum amplitude ratio and the frequency width (Δf) that is 3 dB lower than the maximum amplitude ratio were measured, and the loss coefficient 5 6 number η was determined by the following equation (half width method).

η-Δf/fr The depth of the intergranular corrosion layer was measured by polishing the sample cross section and using an optical microscope. These measured values are also listed in Table 1.

Table 1 As is clear from Table 1, comparative products No. 10 to 12, which differ from the composition of the alloy of the present invention, were unable to preferentially corrode grain boundaries even if they were subjected to corrosion treatment, resulting in a full-scale dissolution type of corrosion. Therefore, the loss coefficient η showed a low value. Comparative product N, which has the composition of the alloy of the present invention but has a grain boundary corrosion layer of less than 20
o13.14 also has a low loss coefficient η. On the other hand, materials impregnated with resin exhibit a higher loss factor η than materials treated only with intergranular corrosion treatment, and this is particularly noticeable in materials with intergranular corrosion layers of 20μ or more.

Example 2 An aluminum alloy ingot having the composition No. 3 in Table 1 was hot rolled and cold rolled into a plate material with a thickness of 2 mm, and after solution treatment at 490°C for 8 hours, various conditions shown in Table 2 were applied. The same precipitation treatment as in Example 1 was performed, and the same intergranular corrosion treatment and resin impregnation as in Example 1 were performed. Measure the loss coefficient η for these,
The results are also listed in Table 2.

9 As is clear from Table 2, products Nos. 21 to 25 of the present invention, which were subjected to precipitation treatment by the production method of the present invention to form intergranular corrosion layers of 201 M or more, exhibit high loss coefficients η.

On the other hand, comparative product N with precipitation treatment that deviates from the production method of the present invention
o26-30 cannot cause intergranular corrosion, and the loss coefficient η is also a low value. Furthermore, the material impregnated with resin as in Example 1 shows a higher loss factor η than the material treated only with intergranular corrosion treatment.

Example 3 An aluminum alloy ingot having the composition shown in Table 3 was hot-rolled and cold-rolled into a plate material with a thickness of 2 mm.

Next, after solution treatment at 490°C for 8 hours, 150'C
grain boundary precipitation treatment for 12 hours, followed by 3% Na (1
It was immersed in +1% HCj2 solution (50°C) to form intergranular corrosion layers of various depths. In addition, some of these intergranular corrosion-treated materials were impregnated with polyethylene resin by a dipping method to completely fill the intergranular voids in the intergranular corrosion layer. A test piece with a thickness of 2 mm, a width of 10 mm, and a length of 250 mm was cut out from this, and its vibration damping property (loss coefficient η) was evaluated in the same manner as in Example 1.

The depth of the intergranular corrosion layer was measured by polishing a cross section of the sample and using an optical microscope. These measured values are also listed in Table 3.

As is clear from Table 3, comparative products Nos. 39 to 41, which differ from the composition of the alloy of the present invention, were unable to preferentially corrode the grain boundaries even if they were subjected to corrosion treatment, resulting in full-scale dissolution type or pitting type corrosion. The loss coefficient η showed a low value.

Note that No. 42 could not be rolled to a thickness of 2 mm. Comparative product N has the composition of the alloy of the present invention but has an intergranular corrosion layer of less than 20 μm.

No. 43 also has a low loss coefficient η. On the other hand, materials impregnated with resin exhibit a higher loss factor η than materials treated only with intergranular corrosion treatment, and this is particularly noticeable in materials with intergranular corrosion layers of 20 μm or more.

Example 4 An aluminum alloy ingot having composition No. 32 in Table 3 was hot-rolled and cold-rolled into a 2 mm thick plate material, and heated at 490°C.
After solution treatment for 8 hours, precipitation treatment was performed under the various conditions shown in Table 4, and the same intergranular corrosion treatment and resin impregnation treatment as in Example 3 were performed. The loss coefficient η was measured for these, and the results are also listed in Table 4.

4 As is clear from Table 4, the product NoA=E of the present invention, which was subjected to precipitation treatment by the production method of the present invention to form an intergranular corrosion layer of 20 p or more, exhibits a high loss coefficient η.

On the other hand, comparative product N with precipitation treatment that deviates from the production method of the present invention
In oF to J, intergranular corrosion cannot occur, and the loss coefficient η is also a low value. Further, as in Example 3, the material impregnated with resin shows a higher loss factor η than the material treated only with intergranular corrosion treatment.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to obtain an aluminum alloy vibration damping material that is lightweight, has excellent cold workability, and has excellent vibration damping properties because it uses aluminum as its base, and is an industrially outstanding material. It is effective.

[Brief explanation of drawings]

Figure 1 shows the vibration resonance curve.

Claims (8)

[Claims] (1) An aluminum alloy containing 2 to 11 wt% of Mg and 0.3 to 10 wt% of Si, with the remainder being Al and inevitable impurities, is characterized by forming an intergranular corrosion layer with a depth of at least 20 μm or more from the surface. Aluminum alloy vibration damping material. (2) An intergranular corrosion layer impregnated with resin to a depth of at least 20 μm from the surface is formed on an aluminum alloy containing 2 to 11 wt% Mg and 0.3 to 10 wt% Si, with the remainder being Al and unavoidable impurities. An aluminum alloy vibration damping material featuring: (3) Contains Mg2-11wt%, Si0.3-10wt%, and further includes Mn0.01-2.5wt%, Cu0.0
1 to 1 wt%, Cr0.01 to 2.0 wt%, Zr0.
01-0.4wt%, Ti0.005-1.0wt%,
B0.0001~0.1wt%, Ni0.05~3wt
%, V0.01 to 2 wt% of one or more of the element groups, and the balance is Al and unavoidable impurities, forming an intergranular corrosion layer with a depth of at least 20 μm from the surface. An aluminum alloy vibration damping material characterized by: (4) Contains Mg2-11wt%, Si0.3-10wt%, and further includes Mn0.01-2.5wt%, Cu0.0
1 to 1 wt%, Cr0.01 to 2.0 wt%, Zr0.
01-0.4wt%, Ti0.005-1.0wt%,
B0.0001~0.1wt%, Ni0.05~3wt
%, V0.01 to 2 wt% of the element group, and the balance is Al and inevitable impurities, and the aluminum alloy is impregnated with resin at a depth of at least 20 μm from the surface. An aluminum alloy vibration damping material characterized by the formation of a corrosion layer. (5) After solution-treating an aluminum alloy containing 2 to 11 wt% Mg and 0.3 to 10 wt% Si, with the remainder being Al and unavoidable impurities, the aluminum alloy is heated at 100 to 250°C for over 1 hour to form grain boundaries. Potentially base precipitates are precipitated and then subjected to corrosion treatment to remove at least 20% from the surface.
A method for producing an aluminum alloy vibration damping material, characterized by forming an intergranular corrosion layer with a depth of 0 μm or more. (6) An aluminum alloy containing 2 to 11 wt% Mg, 0.3 to 10 wt% Si, and the remainder Al and unavoidable impurities is solution-treated and then heated at 100 to 250°C for over 1 hour to form grain boundaries. An aluminum alloy characterized by precipitating electrically base precipitates, followed by corrosion treatment and resin impregnation treatment to form a resin-impregnated intergranular corrosion layer at a depth of at least 20 μm from the surface. Method of manufacturing vibration damping material. (7) Contains Mg2-11wt%, Si0.3-10wt%, and further includes Mn0.01-2.5wt%, Cu0.0
1 to 1 wt%, Cr0.01 to 2.0 wt%, Zr0.
01-0.4wt%, Ti0.005-1.0wt%,
B0.0001~0.1wt%, Ni0.05~3wt
%, V0.01-2wt% of an aluminum alloy containing one or more of the element groups, and the remainder consisting of Al and unavoidable impurities.
Heating at 0°C for 1 hour or more to precipitate potentially base precipitates at grain boundaries, followed by corrosion treatment to form an intergranular corrosion layer with a depth of at least 20 μm from the surface. A method for producing a featured aluminum alloy vibration damping material. (8) Contains Mg2-11wt%, Si0.3-10wt%, and further includes Mn0.01-2.5wt%, Cu0.0
1 to 1 wt%, Cr0.01 to 2.0 wt%, Zr0.
01-0.4wt%, Ti0.005-1.0wt%,
B0.0001~0.1wt%, Ni0.05~3wt
%, V0.01-2wt% of an aluminum alloy containing one or more of the element groups, and the remainder consisting of Al and unavoidable impurities.
Grains heated at 0°C for 1 hour or more to precipitate potentially base precipitates at grain boundaries, and then subjected to corrosion treatment and resin impregnation treatment to be impregnated with resin to a depth of at least 20 μm from the surface. A method for producing an aluminum alloy vibration damping material, the method comprising forming an interfacial corrosion layer.