JPH03120331A - Aluminum alloy high damping material and its manufacture - Google Patents

Abstract

PURPOSE:To obtain the Al alloy high damping material having excellent cold workability and vibration damping properties by subjecting an Al alloy contg. specified Mn to cold working at a prescribed working ratio and regulating its loss coefficient into a prescribed one. CONSTITUTION:An Al alloy constituted of, by weight, 0.5 to 20% Mn and the balance Al is refined. The Al alloy is subjected to cold working at >=30% working ratio to regulate its loss coefficient eta into >=0.006. The Al alloy is lightweight and has excellent cold workability as well as excellent vibration damping properties.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to aluminum alloy vibration damping materials that have excellent vibration damping properties and are used as structural members that dislike vibrations in audio equipment, precision equipment, automobiles, etc. The present invention relates to a manufacturing method thereof.

[Conventional technology]

Generally, when an object is vibrated, the amplitude increases rapidly at a certain frequency (f r) (Figure 1).This frequency is called the resonant frequency, and if the maximum amplitude at the resonant frequency is A, then l/ 2 means the amplitude is A.

/J<-3dB in dB).

If this frequency width (half width) is Δf, the loss coefficient η is expressed by the following equation.

η-Δr/f r Materials with a large value of this loss coefficient η have excellent vibration damping ability, and vibrations are rapidly damped when external force is removed. 0 The loss coefficient η of ordinary metal materials is 0.001 It is as follows.

Conventionally, metal materials for structural members that dislike vibration such as audio equipment, precision equipment, and automobiles, so-called vibration damping materials, have been used.
Fe-Cr series, Mn-Cu series, Zn-Al series, Ni-T
Alloys such as i-series are known. Also, Mg, Mg-Zr
Cast materials of this type are also known as vibration damping materials.

[Problem to be solved by the invention]

However, Fe-Cr series, Mn-Cu series, Zn-Aj
! Alloys such as Ni-Ti and Ni-Ti have high vibration damping properties, but 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 for Solving the Problems] In view of this, 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, and a method for manufacturing the same.

That is, the invention of claim 1 contains 0.5 to 20i1L% of Mn, and the balance is Al and unavoidable impurities, and the loss coefficient I is 0.
．． It is an aluminum alloy vibration damping material characterized in that the Mn is 006 or more, and the invention of claim 2 is an aluminum alloy vibration damping material characterized in that the Mn is
11%, with the remainder consisting of Al and unavoidable impurities
A method for producing an aluminum alloy vibration damping material, characterized in that the l alloy is subjected to cold working at a working rate of at least 30% or more so that the loss coefficient η becomes 0.006 or more, and the invention according to claim 3 further provides , Mno, 5 to 20 wt%,
The remainder consists of Al and inevitable impurities. ! 200-52 immediately after hot working or after cold working the alloy.
A method for producing an aluminum alloy vibration damping material, characterized in that precipitation treatment is performed for 0'C7-1 hour or more, and cold working is further applied at a working rate of at least 30%, so that the loss coefficient η is 0.006 or more. It is.

[Effect]

Damping materials are classified into dislocation type, composite type, ferromagnetic type, and twin type depending on their vibration damping mechanism, and the vibration damping material according to the present invention falls under the dislocation type. In other words, Al distributed inside the alloy
The vibration damping effect is achieved through the interaction of -Mn-based fine intermetallic compounds and dislocations introduced by cold working.

Mn is A7! By adding it to the matrix, a fine Al2-Mn-based intermetallic compound is formed which is uniformly distributed in the matrix. This Al-Mn-based intermetallic compound quickly consumes the vibrational energy when vibration is applied due to interaction with dislocations introduced by cold working, that is, by repeating the temporary fixation and detachment of moving dislocations. , extremely high vibration damping properties can be obtained.

As mentioned above, <Mn is an extremely effective A/
! - It is added to form a Mn-based intermetallic compound, and the content is limited to 0.5 to 20 wt%. 20-t%
If it exceeds 100%, the effect will be saturated and cold working will become impossible.

Note that Ti and B, which are usually added as refiners for the casting structure,
are preferably added in a range of 0.05 wt% or less, respectively, and Fe is added together with Mn Aj! --Fe-Mn
It is preferable to add in a range of 5% or less because it forms a system intermetallic compound and further improves vibration damping properties.Other impurities contained in ordinary Al metal such as St and Cu include Q,
If the amount is less than 5 wt%, the effects of the present invention will not be particularly affected.On the other hand, since the addition of Mg lowers the vibration damping properties of the material, it is desirable to limit it to less than 0.5 wt%.

The Al alloy with the above composition is melted and cast using a normal method, subjected to homogenization treatment if necessary, and then hot worked,
It is finished into a predetermined size by performing cold working or intermediate annealing before or during cold working. that time! l The final cold working rate must be 30% or more. This is the aforementioned dislocation and A/! This is because dislocations are introduced by cold working in order to obtain vibration damping properties based on the interaction of -Mn-based intermetallic compounds, and no effect can be obtained if the working is less than 30%.

Furthermore, a treatment for actively precipitating intermetallic compounds may be performed before the final cold working. This precipitation treatment was carried out at 200 to 520°C for more than 1 hour at 200°C.
Below, AN-Mn-based intermetallic compounds do not precipitate, and 52
This is because the Al-Mn-based intermetallic compound re-dissolves at temperatures above 0°C. Furthermore, if the heat treatment time is less than 1 hour, the amount of precipitation will be insufficient, so the reason why cold working of at least 30% or more is further performed after the precipitation treatment is due to the above-mentioned reason.

〔Example] The present invention will be explained in more detail below using examples.

Example 1 A He2 alloy having the composition shown in Table 1 was melted and cast to a thickness of 50 mm.
The ingot was 0a*, width 1200m, and length 3000mm.

After cutting, the material was homogenized at 560° C. for 10 hours, then hot rolled to various thicknesses shown in Table 1, and then cold rolled to obtain a final thickness of 2++a.

A test piece with a thickness of 2u, a width of 10m+, and a length of 250a* was cut out from this, and its vibration damping property (loss coefficient 77) was evaluated by the cantilever vibration method. That is, one end of the test piece was chaffed to forcibly vibrate with an oscillator, and the loss coefficient η at the resonant frequency "r" was determined using equation (1).
Also listed in the table.

ηFuΔr/f r・・・・・・・・・・・・・・・
(1) However, Δf has a value range of 3 dB.As is clear from Table 1, the Al alloy vibration damping material (Nnl-5) manufactured by the method of the present invention all exhibits a loss coefficient η of 0.006 or more, and has excellent vibration damping properties. It turns out that it has.

On the other hand, the comparative method stone 6 which does not have the alloy composition of the present invention and the comparative method Nα7.8 which has a cold working rate of less than 30% have low loss coefficient ηΦ values.

Example 2 An alloy having the composition shown in Table 2 was melted and cast to form an ingot having a thickness of 500 mm, a width of 1200 mm, and a length of 3000 mm. After cutting this, it was homogenized at 560℃ for 10 hours, and the thickness was 5.
A was hot-rolled, subjected to precipitation treatment under the conditions shown in Table 2, and then cold-rolled to obtain a plate with a final thickness of 2 mm.

From this, as in Example 1, the thickness is 21, the radius is 1OaI11,
A test piece with a length of 250 mm was cut out, and the loss coefficient η at the resonant frequency was determined. The results are also listed in Table 2.

As is clear from Table 2, all of the Al alloy damping materials (kl~5) produced by the method of the present invention were compared to A, which differs from the method of the present invention.
It can be seen that the material exhibits a higher loss coefficient η than the l-alloy damping material (N116-8) and has excellent vibration damping properties.

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

[Brief explanation of the drawing]

FIG. 1 is a vibrational resonance curve.

Claims (3)

[Claims] (1) An aluminum alloy vibration damping material comprising 0.5 to 20 wt% of Mn, the balance being Al and unavoidable impurities, and having a loss coefficient η of 0.006 or more. (2) A working rate of at least 30
A method for producing an aluminum alloy vibration damping material, characterized in that it undergoes cold working of 0.006% or more and has a loss coefficient η of 0.006 or more. (3) Immediately after hot working or after cold working, an Al alloy containing 0.5 to 20 wt% Mn and the remainder Al and unavoidable impurities is subjected to precipitation treatment at 200 to 520°C for 1 hour or more. furthermore, the processing rate is at least 30
A method for producing an aluminum alloy vibration damping material, characterized in that it undergoes cold working of 0.006% or more and has a loss coefficient η of 0.006 or more.