JPH01255654A - Manufacturing method for vibration-proof aluminum alloy members - Google Patents

Abstract

PURPOSE:To obtain an Al alloy member excellent in vibration absorbing property by subjecting the surface layer part of the Al alloy member which has a composition containing, besides Si, one or more kinds among Fe, Ni, etc., and rare earth elements and in which average grain size of secondary-phase grains is specified to softening by means of physical working. CONSTITUTION:The Al alloy member which has a composition containing, by weight, 8-20% Si and 0.05-2.5% of one or more kinds among Fe, Ni, Zr, V, B, Ti, Na, Sn, Ca, Sr, and rare earth elements and in which average grain size of secondary-phase grains is regulated to <=10mum is prepared. Subsequently, the surface layer part of the above Al alloy member is subjected to physical workings of compression, tension, shearing, etc., by means of shot peening working, etc., and then to annealing treatment at <=300 deg.C, by which the surface layer part is softened. By this method, the Al alloy member suitably used for purposes such as prevention of adverse effects due to the vibration and noise of various equipment and excellent in vibration absorbing property can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing a vibration-proof aluminum alloy member. Specifically, the present invention is suitably used for purposes such as preventing damage caused by vibration and noise of various types of equipment. This invention relates to a method of manufacturing an aluminum alloy member with excellent vibration damping properties.

[Conventional technology]

This is one of the vibration-proof alloys currently in practical use.

There are Fe-based alloys, N1-based alloys-Mn-based alloys, Zn-based alloys, and ■-based alloys.

[Problem to be solved by the invention]

However, each of these alloys has a high specific gravity, requires complicated manufacturing conditions, and is expensive.

It has problems such as poor corrosion resistance.

On the other hand, although aluminum alloys are lightweight, have excellent specific strength and corrosion resistance, and are reasonable in terms of cost, they have not been put to practical use until now because of their vibration-proofing properties.

On the other hand, the present inventor has previously determined that Sig-, z o wt
%, Fe-Ni, Zr, V-B, Ti,
Na-Sn.

Aluminum containing a total of 0.05 to 2.5 wt% of one or more elements selected from the group consisting of Ca + Sr and rare earth elements, and whose second phase particles have an average particle diameter of 10 μm or less It was discovered that the alloy has excellent anti-vibration properties.

Incidentally, anti-vibration alloys are actually used as various product members, but the anti-vibration performance of such members is often influenced by their shape.

In some cases, the desired performance was not achieved.

[Means to solve the problem]

Therefore, as a result of intensive studies to solve these problems with the prior art, the inventors of the present invention have found that by modifying the surface layer of the aluminum alloy member using a specific method, the vibration damping performance of the member can be improved. By discovering this, we have arrived at the inventions of the present application.

That is, the gist of the first invention of the present application is that Si g
~: l O%- and Fe-Ni, Zr, V.

A total of at least one element selected from the group consisting of B-Ti-Na-Sn, Ca, Sr, and rare earth elements is 0. It has a composition containing Oj-2.5%, the balance consisting of aluminum and impurities with a total content of O, S% or less,
and the average particle size of the second phase particles is i.

The present invention relates to a method for manufacturing a vibration-proof aluminum alloy member, characterized in that the surface layer of a member made of an aluminum alloy having a particle size of .mu.m or less is subjected to physical processing to soften the surface layer.

In addition, the second gist of the present invention is to physically process the surface layer of the member made of the aluminum alloy, and then perform an annealing treatment at a temperature of 300°C or less to soften the surface layer. The present invention relates to a method for producing a vibration-proof aluminum alloy member, characterized in that:

One method of the present invention will be explained in detail below.

In the method of the present invention, 1% by weight is 81g to 2o%.
, and Fe-Ni II Zr, V, B, T
i.

A total of 0.05 to 2 of at least one element selected from the group consisting of Na-Sn, Ca-Sr and rare earth elements.
．． 5%, the balance is aluminum and total O, S%
An aluminum alloy having a composition consisting of the following impurities and whose second phase particles have an average particle size of 70 μm or less is used. Among the impurities below the total O and S%, Cu is particularly important.

(2) The total amount of Zn is preferably 0.3% or less, more preferably 0.1% or less.

When Si is added to At, the matrix At
Si particles are precipitated inside to form a eutectic structure. The second phase, the interface between the 81 particles, absorbs vibrations and improves the damping ability, but if the Si content is less than 5%, sufficient damping ability cannot be obtained because fewer second phase particles are formed. , on the other hand.

When it is more than 20%, coarse second phase particles are produced, so that the damping ability is not improved and the mechanical properties and machinability are inferior. Therefore, the amount of Si added is in the order of g-20, preferably 9 to t.
g%.

Fe, Ni, Zr, V, B, Ti, Na, Sn, Ca-
8r and rare earth elements refine the crystals, increase grain boundaries, and form fine second phase particles to improve the damping ability. If the total amount of these elements is less than 0.05%,
If the effect of crystal refinement is not sufficient and the total amount of these elements exceeds 2.5 inches, coarse intermetallic compounds are formed and the damping ability and mechanical properties are impaired. Therefore, the amount of these additions is 0.0;-2,! ;%, preferably 0.
06% to 2.0%.

In addition, in the aluminum alloy used in the present invention,
In addition to having the above-mentioned specific composition, it is necessary for the crystal structure that the average particle size of the second phase particles is less than lθ fine.

That is, by setting the average particle diameter of the λ-phase particles to 10 μm or less, the interface of the λ-phase particles can be increased, thereby making it possible to obtain a damping capacity of Q-I = s X / 0-3 or more. . The average particle size is more preferably 7 μm or less, and even more preferably 5 μm or less.

Here, the above-mentioned damping capacity Q-1 indicates a measure of converting externally applied vibration energy into thermal energy, and the vibration energy E possessed by the vibration system at the beginning of 1 cycle of vibration, and the vibration energy E possessed by the vibration system during 1 cycle of vibration. If ΔE is the energy that is converted into thermal energy, there is a relationship as shown in the following equation.

As for the method of controlling the above-mentioned organization.

There are a method of rapid cooling during solidification from a molten liquid and a method of physically dividing the second phase particles by strong processing.

Specifically, continuous casting is a rapid cooling method.

Roll casting method, die casting method, atomization method, etc.
In addition, strength processing methods include a rolling method, a rolling method, an extrusion method, a drawing method, and the like.

Now, in the method of the present invention, the vibration-isolating performance can be further improved by modifying the surface layer of product parts of various shapes made of a vibration-isolating aluminum alloy having the above-mentioned specific composition and structure in a specific manner. It is characterized by improving

In other words, it focuses on the fact that vibrations from the outside are transmitted to the inside of a member through the surface layer, and attempts to attenuate vibrations in the surface layer by improving internal friction in the surface layer. be.

The first method for modifying the surface layer is as follows.

This is to soften the surface layer by subjecting the surface layer to physical processing.

The above-mentioned physical processing is 1.For example, processing force such as compression, tension, shearing, etc. is applied to the surface layer, such as shot peening processing (shot blasting method), honing processing, spinning processing, pultrusion processing, press forming processing, hairline processing, or cutting processing. This is done by a loading method. -Although the aluminum alloy inside the film is hardened by the above processing.

In the case of the alloy used in the method of the present invention, when the processing rate exceeds 30%, it exhibits a unique phenomenon of softening due to processing, and the processed surface layer becomes soft. This softening phenomenon is due to the formation of fine cell grain boundaries, and it is thought that these cell grain boundaries increase the internal friction of the crystal and improve the vibration damping performance.

There is no particular limit to the depth of the softening treatment described above, but performing the softening treatment too deeply will unnecessarily reduce the strength of the surface layer and also significantly change the dimensions of the product component itself. So it's not a good thing. The specific depth of treatment may be determined keeping these things in mind, but sufficient results can usually be obtained within 300 μm from the surface, more preferably within /SOItm.

A second method for modifying the surface layer is to subject the surface layer to physical processing and then to annealing at a temperature of 300° C. or lower to soften the surface layer.

Regardless of the processing rate of the physical processing, annealing at a temperature of 3 ooc or less promotes the formation of fine cell grain boundaries. On the other hand, heating at a temperature exceeding 300°C is undesirable because it promotes recrystallization and the cell grains become coarser due to the disappearance and coalescence of cell grain boundaries, so that the internal friction actually decreases.

In addition, the anti-vibration performance can be further improved by etching the surface layer before, after, or in an intermediate step of the above two methods for modifying the surface layer to partially corrode and remove the surface layer. be able to. Specifically, the surface grain boundaries, second phase particles, or aluminum alloy (IJ socks) are partially corroded and removed by chemical etching treatment using chemicals containing chloride ions or hydroxide ions, or electrolytic etching treatment. This forms discontinuities in the crystal, structurally increasing internal friction and improving vibration damping performance.

〔Example〕

Next, aspects of the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to the following Examples unless the gist thereof is exceeded.

In the examples, the damping capacity was measured by the mechanical impedance method at a resonance frequency in the range of SOO to 1oooH, and the hardness was measured by the micro-Vickers hardness method on the cross section of the sample. The diameter was measured using an optical microscope.

Example 1 Alloys A-C having the composition shown in Table 1 were melted in the atmosphere in an electric melting furnace, and then cast by a water-cooled vertical continuous casting method.
! A billet of 78φ was prepared, and then soaked at SOO° C. for g hours.

Next, the billet was hot extruded at qso°C to form a square pipe (cross-sectional outline: 25 Ifi x 2
! 1101. A thickness of 3 rta) was obtained. Then, the surface layer portion of the pipe was treated under the conditions shown in Tables 2 and 3.

Next, cut the pipe to a length of 1 qoran - width of 1
A test piece having a thickness of 0 fm and a thickness of 5I+Im was used to measure the damping capacity.

The results are shown in Table 3.

Table 3 *2) Surface: Measured at a depth of 75 μm per cross section.

*3) Inside: Measured at depth Q, '7;rm per cross section.

Example 1 Alloy D-F having the composition shown in Table q was melted in the atmosphere in an electric melting furnace, and then made into a rectangular container (external diameter: 39111111 X/ j Q a
XcoQIIImH1 wall thickness 85rrrIn) was obtained. The surface layer of the container was then treated under the conditions shown in Tables 2 and 5.

Next, the container is cut to a length of 1IQWm.

Width 10a! A test piece with a thickness of 5-5 was used to measure the damping capacity.

The results are shown in Table 5.

Table S *2) Same as Table 3.

*3) Same as Table 3.

As is clear from Tables 3 and S, the attenuation ability can be improved by performing the surface modification treatment of the present invention.

〔Effect of the invention〕

The aluminum alloy member obtained by the method of the present invention is
Due to its excellent damping performance, it is suitable for use in applications that require vibration isolation, such as OA equipment parts such as platen rolls, acoustic parts such as insulators, automobile parts such as transmission cases, precision machinery parts, and electronic equipment parts. I can do it.

[Brief explanation of the drawing]

FIG. 1 is a perspective view schematically showing the shape of the member manufactured in Example 1. FIG. 2 is a perspective view schematically showing the shape of the member manufactured in Example I. Patent applicant Naoe Tsuyoshi Kasei Co., Ltd. Agent Patent attorney Yo Hase - and 1 other person Figure 1 Figure 2

Claims (4)

[Claims] (1) Si 8-20% by weight percentage, as well as Fe, Ni
, Zr, V, B, Ti, Na, Sn, Ca, Sr, and rare earth elements in a total of 0.05 to 2.5%, with the remainder being aluminum and A member made of an aluminum alloy having a composition consisting of impurities of 0.5% or less in total and an average grain size of second phase particles of 10 μm or less is subjected to physical processing on its surface layer to form a surface layer. A method for manufacturing a vibration-proof aluminum alloy member, characterized by softening the parts. (2) The method for producing a vibration-proof aluminum alloy member according to claim 1, characterized in that the surface layer is partially corroded and removed by etching the surface layer before or after the physical processing. Method. (3) Si 8-20% by weight percentage, as well as Fe, Ni
, Zr, V, B, Ti, Na, Sn, Ca, Sr, and rare earth elements in a total of 0.05 to 2.5%, with the remainder being aluminum and After physical processing is applied to the surface layer of a member made of an aluminum alloy having a composition consisting of impurities of 0.5% or less in total and an average particle size of second phase particles of 10 μm or less. A method for producing a vibration-proof aluminum alloy member, characterized in that the surface layer is softened by annealing at a temperature of 300° C. or lower. (4) In the method for manufacturing a vibration-proof aluminum alloy member according to claim 3, etching treatment is performed on the surface layer before the physical processing treatment, between the physical processing treatment and the annealing treatment, or after the annealing treatment. A method characterized by partially corroding and removing the surface layer.