JPH0327619B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention provides vibration damping that is optimal for preventing pollution caused by vibrations and noises of various transportation systems and large machines, performance deterioration caused by vibrations of various precision machines and electronic devices, and harmful effects of various vibrations and noises that exist in the living environment. This study concerns an Al-Sn vibration-absorbing alloy with high performance. Attenuation capacity generally used to compare attenuation capacity
Q ^-1 has a relationship with the vibrational energy ΔE lost during the vibration cycle and the total vibrational energy E as shown in the following equation. Q ^-1 = 1/2π·ΔE/E In other words, the larger the value of the damping capacity Q ^-1 , the smaller the amplitude becomes in a shorter time and the greater the damping effect. Conventionally known vibration absorbing alloys include Fe-based alloys such as dientalloy, Mn-Cu alloys, and Al-Cu alloys.
-Ni-based alloys and Ni-Ti-based alloys. Fe-based vibration-absorbing alloys such as Dientalloy and Mn-Cu-based alloys have high damping ability, but their specific gravity is around 8 g/ ^cm3 , making them unsuitable when reducing the weight of equipment.Al-Cu-Ni The disadvantage of these alloys is that they have poor cold workability and are completely impossible to cold work. In order to obtain a vibration-absorbing alloy that is lighter than conventional vibration-absorbing alloys, the present invention is based on Al, which has a very low specific gravity of 2.7 g/ ^cm3 , and is made of an alloy with 0.1 to 60% tin added by weight. The object of the present invention is to provide a vibration-absorbing alloy which is subjected to cold working at a rate of 5% or more to increase the transition, annealed at 150°C or less as necessary, and has a large damping capacity and high strength due to the hysteresis phenomenon. Next, a method for manufacturing the alloy of the present invention will be explained. First, an alloy with the above composition range is melted in an ordinary melting furnace in air, an inert gas, or a vacuum, and then sufficiently stirred to form a uniform molten metal.Then, the alloy is poured into a sand mold or metal mold, and an ingot is poured into an ingot. Build. Next, this ingot is subjected to the following heat treatment. (A) For homogeneous solution treatment, heat at a temperature as high as possible, for example, at a temperature of 150°C or higher below the melting point of the alloy, for at least 5 minutes as long as possible (preferably at least 5 minutes and up to 100 hours), and then rapidly cool or Cool slowly at a rate below ℃. (B) Next, cold working is performed at room temperature by forging, rolling, extrusion, swaging, or drawing at a cold working rate of 5% or more in order to obtain the large damping capacity that is the objective of the present invention. (C) A material that has been subjected to cold working with a cold working rate of 5% or more in (B) is heated at a temperature of 150°C or less for 1 minute or more (preferably for 1 minute or more and within 500 hours) and then rapidly cooled, or at 1°C per second. Cool slowly at the following speed. Incidentally, when dissolving, a flux of MgCl ₂ , borax, CaF ₂ , KCl, etc. in a total amount of 5% or less may be added as a blocking agent, and a total amount of 0.5% or less of magnesium, beryllium, etc. may be added as a deoxidizing agent. In the homogeneous solution treatment step (A), if the heating temperature is high, the heating time must be shortened, and if the heating temperature is low, the heating time must be lengthened. On the other hand, if the weight of the molded object is large, it is necessary to raise the heating temperature and lengthen the heating time, but if the weight of the molded object is small, it may be heated at a relatively low temperature for a short time. The reason for this is that unless homogeneous solution treatment is sufficiently performed, product performance such as damping capacity cannot be made uniform. Cold working in step (B) following the homogeneous solution treatment step (A) increases the dislocation density by processing,
This is an essential step in order to obtain a large damping capacity through the hysteresis phenomenon, and is also necessary to increase the tensile strength of the molded article. In order to increase the damping capacity, cold working of 5% or more is enough to achieve the purpose, but the strength of the working condition,
That is, when the cold working rate is as high as 70 to 95%, or
Some alloys with a large amount of Sn have extremely low elongation, making them difficult to form by bending, deep drawing, punching, etc. Therefore, when heated to a temperature of 150°C or less in step (C) after cold working in step (B),
The elongation increases, allowing for bending, deep drawing, and
Forming such as punching becomes easier. 150 in process (C)
The reason for setting it below ℃ is that when heated above 150℃, the elongation suddenly increases and workability improves, but the damping capacity is 4×
This is because the value drops below 10 ^-3 and the intended purpose cannot be achieved. Next, examples of the present invention will be described. Example: A total of 100 g of metal having the composition shown in Table 1 was melted in an alumina crucible in a high-frequency induction electric furnace while passing Ar gas to the surface, and cast into an iron mold with a diameter of 10 mm.
An ingot was obtained. Next, this was heated at 200° C. for 10 hours and slowly cooled, and then cold swaged and drawn into a 1.1 mm wire, from which a 150 mm long wire was cut to serve as a sample. The damping capacity Q ^-1 was measured by the inverted torsion pendulum method at a frequency of about 1 Hz and a maximum strain amplitude γ _n =10×10 ^-6 . The damping capacity Q ^-1 and strength of Al-based alloys depend on the cold working rate. As an example, Figures 1 and 2 show that after heating an Al-40%Sn alloy at 200℃ for 10 hours,
The relationships between the damping capacity Q ^-1 and the tensile strength σ _t and the cold working rate when slowly cooled and processed by cold swaging and drawing are shown, respectively. Both the damping capacity Q ^-1 and the tensile strength σ _t increase as the cold working rate increases. This is the result of an increase in dislocation density as processing strain increases.
As a result, the objective of the present invention is the damping capacity Q ^-1 = 6
It can be seen that in order to obtain a value of ×10 ^-3 or more (γ _n =10×10 ^-6 ), it is necessary to perform cold working of 5% or more. Next, Table 1 shows the relationship between cold working rate and damping capacity Q ^-1 for Al-Sn binary alloys.

[Table] As is clear from Table 1, aluminum subjected to cold working with a cold working rate of 95% has a damping capacity Q ^-1 of 4×
10 ^-3 , which is inappropriate as a vibration absorbing material for the purpose of the present invention, but if 0.1% or more of tin is added to aluminum, a large value of Q ^-1 = 6 × 10 ^-3 or more, which is the purpose of the present invention, can be obtained. I know that it will happen. In short, the value of the damping capacity Q ^-1 of the alloy of the present invention is several tens of times larger than the value of Q ^-1 =1×10 ^-3 of ordinary metals. As described above, in the present invention, the damping increases as the cold working rate increases from 5% to 95%, but elongation decreases, making it brittle and reducing workability.
It is necessary to anneal at a temperature below ℃. Annealing at a temperature of 150°C or lower increases elongation and makes processing easier, but the damping ability decreases slightly, but this is not a problem. This is because the number of dislocations increased by processing is annealed by annealing, resulting in fewer dislocations. In addition,
When the annealing temperature is raised to 150° C. or higher, the elongation increases rapidly to 35% or higher, but the damping capacity Q ⁻¹ becomes 4×10 ⁻³ or lower, and the object of the present invention cannot be obtained. Furthermore, the specific gravity ρ of the alloy of the present invention is 7 to 7 of that of general metals.
The tensile strength σ t is considerably smaller than 9 g/cm ³ , and the tensile strength σ _t is considerably higher than 10 Kg/mm ² for cold-worked aluminum. For example, sample No. 5 of the example has σ _t =19
Kg/mm ² , ρ=3.3g/cm ³ . Finally, the reason for limiting the composition of the alloy of the present invention will be described. Add tin to the weight ratio of 0.1 to improve the damping capacity Q ^-1 .
The reason why it is limited to 60% is that if the lower limit of the composition is not reached, the sufficient damping ability aimed at by the present invention cannot be obtained, and if the upper limit of the composition is exceeded, the strength will be reduced. For homogeneous solution treatment, heating at a temperature of 150° C. or higher and below the melting point of the alloy for a long period of time and sufficiently homogeneous solution treatment is absolutely necessary in order to obtain the required damping ability, strength, and workability. Note that performing cold working at a cold working rate of 5% or more is an absolutely necessary condition for increasing the damping capacity by increasing the working strain and dislocation density. When tin is added to aluminum and dissolved, the aluminum and tin do not form a solid solution, but the tin appears to be dispersed as fine particles in the aluminum matrix. When a compact of such an alloy is subjected to homogeneous solution treatment by heating it for a long time at a high temperature of 150° C. or higher below the melting point of the alloy, the state of dispersion of tin particles in the aluminum matrix becomes homogeneous. When this is subjected to cold working at a cold working rate of 5% or more, tin particles are finely dispersed and the dislocation density becomes large. When this dislocation density increases, when vibration is applied from the outside, the applied external force (vibration, impact, torsion,
(compression, tension, etc.) disappears as thermal energy, resulting in vibration damping. Therefore, in order to increase the attenuation capacity, it is necessary to
Long-term heating at higher temperatures and cold working of 5% or more are sufficient to achieve the objective, but if the cold working rate is increased to 70-95% or alloys with a large amount of Sn are Depending on the composition, bending,
Some products are difficult to form by deep drawing, punching, etc. For this reason, when reheated for a long time at a low temperature of 150°C or lower, the damping capacity and strength do not deteriorate significantly, and forming processes such as bending, deep drawing, and punching become extremely easy. In this case, it is not preferable to set the reheating treatment temperature to 150° C. or higher because the damping ability will decrease. As mentioned above, the characteristics of the alloy of the present invention are that it has a large damping capacity, is lightweight, has good cold workability, has high strength, and is non-ferromagnetic. Therefore, the synthesis of the present invention can be applied to various transportation systems, large machines, moving parts of electronic devices, parts operated by magnetic fields, various household goods, and materials for buildings, etc., to prevent vibration and noise, and to reduce weight. very suitable.

[Brief explanation of the drawing]

Figure 1 shows the damping capacity ^Q -1 of Al-40%Sn alloy when heated at 200℃ for 10 hours, slowly cooled, and then cold worked.
FIG. 2 is a characteristic curve diagram showing the relationship between the tensile strength σ _t and the cold working rate of the same alloy as in FIG. 1.

Claims (1)

[Claims] 1. Consisting of 0.1 to 60% tin and the balance aluminum in terms of weight ratio, the damping capacity Q ^-1 with increased dislocation density due to cold working at a cold working rate of 5% or more is 6 x 10 ^{- 3}
An Al-Sn vibration absorbing alloy characterized by the above. 2 For alloys consisting of 0.1 to 60% tin and the balance aluminum by weight, (A) After heating at a temperature of 150°C or higher below the melting point of the alloy for 5 minutes or more and 100 hours or less, the alloy is rapidly cooled or heated at a temperature of 1°C per second or less. (B) A method for manufacturing an Al-Sn vibration absorbing alloy, characterized in that the damping capacity Q ^-1 is made 6 × 10 ^-3 or more by performing slow cooling at a speed of 5% or more. . 3 For alloys consisting of 0.1 to 60% tin and the balance aluminum by weight: (A) After heating at a temperature below the melting point of the alloy and above 150°C for 5 minutes to 100 hours, rapidly cooling or at a temperature below 1°C per second. (B) After being slowly cooled at a speed of 5% or more, (C) The material that has been subjected to the cold working ratio of 5% or more in (B) is cooled at a temperature of 150℃ or less for 1 minute. Attenuation capacity Q ^-1 is increased by 6x by heating for 500 hours or less and then rapidly cooling or slowly cooling at a rate of 1°C or less per second.
A method for producing an Al-Sn vibration-absorbing alloy, characterized in that it has a vibration absorbing alloy of 10 ^-3 or more.