JPH04344A - Aluminum alloy high damping material - Google Patents

Abstract

PURPOSE:To obtain a high damping material, light in weight and excellent in plastic workability as well as damping capacity by incorporating a specified amt. of B and specified amounts of elements in the group of Fe, Si, Cu, Mn, Ni, Hf and rare earth elements into Al. CONSTITUTION:An Al alloy contg., by weight, 0.1 to 20% B, total 0.05 to 20% of one or more kinds among Fe, Si, Cu, Mn, Ni, Hf and rare earth elements and the balance Al with inevitable impurities is prepd. If required, total 0.05 to 10% of one or more kinds among Sb, Bi and Ge are furthermore added to the above components. In this way, the aluminum alloy high damping material light in weight and excellent in plastic workability as well as damping capacity can be obtd. and is suitable as the structural material having an aversion to vibration such as an acoustic device.

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 maximum amplitude at the resonant frequency is Ao, the amplitude that is 1/2 of this energy is Ao /I2
(-3 dB in dB representation). If this frequency width (half width, 3 dB value width) is Δf, the loss coefficient η 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 the external force is removed, the vibration is rapidly damped. 0 The loss coefficient η of ordinary metal materials is 0.001 It is as follows.

Conventionally, Fe has been used as a so-called vibration damping material for structural members of audio equipment, precision equipment, automobiles, etc. that dislike vibration.
-Cr based, Mn-Cu based, ZnAf based, Ni-Ti based alloys, and the like are known.

Furthermore, Mg and Mg-Zr based cast materials are also known as vibration damping materials.

[Problem to be solved by the invention]

However, Fe-Cr series, Mn-Cu series, Zn-Al series,
Alloys such as Ni--Ti have high vibration damping properties, but 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
Cast materials of this type also have the advantage of exhibiting high vibration damping properties and low specific gravity, but have the disadvantage of not being able to be cold-worked at all.

[Means for Solving the Problems] In view of the above, and as a result of various studies, the present invention has developed an aluminum alloy vibration damping material that has a low specific gravity and is easy to cold work.

That is, the present invention contains 8001 to 20 wt%, and further contains F.
A total of 0.05 to 20 wt of one or more of e, Si, Cu, Mn, Ni, Hf, and rare earth elements
Including %, balance A! Claim 1 is an aluminum alloy vibration damping material characterized by comprising B and unavoidable impurities.
Contains 1 to 20 wt% of O3, and further contains one or more of Sb, Bi, and Ge for a total of 0.05 to 10 w.
Claim 2 provides an aluminum alloy vibration damping material characterized in that it contains t% and the balance consists of Al and unavoidable impurities, and B
Contains 0.1 to 20iit%, and further contains Fe, Si
, Cu, Mn, Ni, Hf, and one or more of rare earth elements in a total of 0.05 to 20 wt%,
Claim 3 provides an aluminum alloy vibration damping material which further contains one or more of Sb, Bi, and Ge in a total of 0.05 to 10 wt%, with the balance being An and unavoidable impurities. be.

[Effect]

Damping materials are classified into dislocation type, composite phase type, ferromagnetic type, and twin type depending on their vibration damping mechanism, and the vibration damping material according to the present invention has both of the dislocation type and composite phase type.

By adding B to Al, B forms a fine compound such as AlB2 that is uniformly distributed in the matrix. When vibration is applied to such a material, the compound and A! The vibrational energy is quickly absorbed by the viscous flow at the interface with the matrix (effect as a composite phase type), and the dislocations introduced by plastic working repeatedly attach and detach temporarily from the compound, absorbing the vibrational energy. Absorb(
Effects as a transposed type) Extremely high vibration damping properties can be obtained due to the effect of 0 or more. Addition of B alone is sufficient to exhibit this effect, but addition of Fe, St,
When one or more of Cu, Mn, Ni, Hf, and rare earth elements are added, these also form respective fine compounds, and dislocations are also temporarily fixed/fixed to these compounds.
It repeatedly detaches and absorbs vibrational energy. Furthermore, s
When one or more of b, Bi, and Ge are added, each of these forms a single particle or a compound,
Since vibration energy is absorbed by viscous flow at the interface with the matrix, vibration damping properties can be further improved.

As mentioned above, B is added to form a compound extremely effective in improving vibration damping properties in the 11 matrix, and the content is limited to 0.1 to 2 Qwt% because it is 0.1wt%. If it is less than 20 wt %, the amount of the A RB z compound formed is small and vibration damping properties are poor, and if it exceeds 20 wt %, the effect is saturated and plastic working becomes difficult.

Fe, Si, Cu,
One or more of Mn5Hf, Ni, Hf, and rare earth elements are added, but the content is limited to 0.05 to 20 wt% because if it is less than 0.1 wt%, the compound will be distributed in the matrix. This is because the amount is too small and the effect of improving vibration damping properties is insufficient, and if it exceeds 2Qwt%, the effect is saturated and workability is reduced. Also, Sb,
One or more of Bi and Ge is added, but the content is limited to 0.05 to 10 wt% because if it is less than 0.05@t%, the amount of these particles and compounds is small and vibrations occur. The damping property improvement effect is insufficient, and 10wt%
If it exceeds the limit, the effect will be saturated, and the distribution of particles and compounds will become uneven, causing variations in vibration damping properties. Coarse particles and compounds will be formed, which may deteriorate plastic workability, mechanical properties, corrosion resistance, etc. This is because there is. Rare earth elements are not particularly limited in type, but specifically include Y, La, Ce, Pr, and Nd.

Pm, Sm etc. and mixtures thereof can be used.

The AN alloy with the above composition can be melted and cast using the usual method to form an A1 alloy ingot, but in order to refine the intermetallic compounds and improve vibration damping properties, the rapid solidification powder method is or mechanical alloying method can be used. This /1 alloy ingot is subjected to homogenization treatment as necessary. This homogenization treatment is performed in order to make the distribution state of the added elements more uniform, but it can be heated at a temperature of 150 to 600 ° C for several hours. . The A2 alloy ingot in this state has superior vibration damping properties compared to normal Aj2 metal, but in order to further improve the vibration damping properties, this A1 alloy ingot has an area reduction of 30% or more. Add plastic working. That is, by adding plastic working, the dislocation density increases, and as mentioned above, the vibration energy absorption effect is exhibited by repeated temporary attachment/detachment of dislocations to the compound, and the vibration damping property is improved. The plastic working may be performed by hot working, cold working, or cold working after hot working, and may be performed by any means such as rolling, extrusion, drawing, and forging.

The larger the amount of plastic working, the larger the loss coefficient, and a higher loss coefficient can be obtained with cold working than with hot working, but preferably the area reduction from the ingot to the final processed product is 30. % or more, the loss coefficient will be 40.006 or more regardless of hot working or cold working, and sufficient vibration damping properties can be obtained as a vibration damping material.

In addition, annealing is commonly performed to adjust strength and elongation.
The effect of the present invention will not be impaired even if it is applied after hot working or during cold working, and temper annealing is also applied to the final processed product to adjust the strength and elongation. This tends to reduce the vibration damping properties because it reduces the dislocations introduced by plastic working, but there is no particular problem as long as it is kept at a temperature of 400''C or less for about 24 hours or less.

〔Example〕

Examples of the present invention will be described below.

Example 1 An alloy having the composition shown in Table 1 was melted and cast to a thickness of 500 mm.
The ingot had a width of 1200 m and a length of 3000 m. After cutting, it was homogenized at 500°C for 10 hours, hot rolled to a thickness of 5ml, and then cold rolled to a thickness of 2mm.
It was made into a plate material of m.

From this thickness 2cm, width 10as, length 25oIII11
A test piece was cut out and the vibration damping property (loss coefficient η) was evaluated using the cantilever vibration method. That is, one end of the test piece is chucked and vibration is forcibly applied using an oscillator, and the vibration of the test piece is detected. This input vibration and output (detection) vibration are converted into a 2-channel fast Fourier transformer (2ch, FFT).
) to find the input/output amplitude ratio in the frequency domain.

The loss coefficient η was determined using the following equation at the resonant frequency (fr) exhibiting the maximum amplitude ratio.

η=Δf/f r Δf has a value range of 3 dB. This loss coefficient ηΦ value is also listed in Table 1.

As is clear from Table 1, A1 according to the alloy composition of the present invention
All of the alloy vibration damping materials (No. 1 to 9) exhibit a loss coefficient η of 0.006 or more, indicating that they have excellent vibration damping properties. On the other hand, the comparative alloy Nα10 which deviates from the alloy composition of the present invention
has a loss coefficient η smaller than 0.006, kll, 12
Plastic working could not be performed on Nα13, and the value of loss coefficient η was smaller than 0.006.

[Effects of the Invention] As described above, according to the present invention, since it is based on aluminum, it is possible to obtain an aluminum alloy vibration damping material that is lightweight, has excellent workability, and has excellent vibration damping properties. , which has a remarkable industrial effect.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a resonance curve of vibration.

Claims (3)

[Claims] (1) Contains 0.1 to 20 wt% of B, and also Fe, Si
, containing a total of 0.05 to 20 wt% of one or more of Cu, Mn, Ni, Hf, and rare earth elements,
An aluminum alloy vibration damping material characterized in that the remainder consists of Al and unavoidable impurities. (2) Contains 0.1 to 20 wt% of B, and further includes Sb and Bi
, a total of 0.05 of one or two or more of Ge
An aluminum alloy vibration damping material characterized in that it contains ~10 wt%, and the remainder consists of Al and inevitable impurities. (3) Contains 0.1 to 20 wt% of B, and also Fe, Si
, Cu, Mn, Ni, Hf, and rare earth elements in a total of 0.05 to 20 wt%, and further contains one or more of Sb, Bi, and Ge in a total of 0. An aluminum alloy vibration damping material characterized by containing .05 to 10 wt%, and the remainder consisting of Al and unavoidable impurities.