JPH04187387A - Vibration-proof metallic material - Google Patents

Abstract

PURPOSE:To improve heat resistance and workability by using one of two kinds of metallic materials having specified acoustic impeadance ratio as the central material and performing metallic joining as the other metallic material is used for the upper and lower surfaces as clad material. CONSTITUTION:As one of two kinds of metallic materials wherein an acoustic impeadance ratio to a longitudinal or a transversal wave exceeds 2:1 is used as the central material 1 and the other metallic material is used for the upper and lower surfaces of this central material l as clad material 2, these metals are joined to form vibration-proof metallic material composed of clad material. For example, A as the central material 1 and carbon steel as the clad material 2 on both sides of it are joined. In this case, since the impeadance ratio of steel to Al is 2.7, a loss of energy of 5% is generated. Since this loss of energy acts repeatedly on the longitudinal wave transmitted through vibration-proof metallic material, the vibration is attenuated by the repeated effect. Consequently, this vibration-proof metallic material is excellent in heat resistance and workability because it does not use high polymer material.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a vibration-proof metal material that has excellent vibration damping characteristics and good workability and formability.

(Prior art) Recently, there have been many pollution problems caused by vibrations emitted by machine tools, industrial machinery, etc., and noise emitted by transportation such as trains and automobiles when they run at high speed or pass over bridges, etc. However, there are expectations from various quarters that vibration and noise can be reduced by applying anti-vibration metal materials to such machines and structures.

Generally, the following three methods can be considered as methods for damping vibrations.

■ A method of absorbing vibration energy by installing an external damper system, such as an oil damper or an air damper.

■ Method of sandwiching a viscoelastic polymer material between metal materials 0 This is a method of absorbing vibration energy through the sliding deformation of the viscoelastic polymer material accompanying bending vibration.

■ A method of imparting large damping capacity to the metal material itself,
This is a method of absorbing vibration energy using materials called anti-vibration alloys, vibration-absorbing alloys, vibration-damping alloys, etc., which were born from a completely different idea from conventional ones. It is.

Figure 2 is a diagram showing the relationship between the tensile strength and vibration damping coefficient of metal materials (New Materials Handbook 1990J, page 334, published by the Japan International Trade and Industry Materials Investigation Committee on April 16, 1990). A material with a large damping capacity and high strength is a vibration-isolating alloy (also called a vibration-absorbing alloy or a vibration-damping alloy).

(Problems to be Solved by the Invention) The conventional vibration damping method described above has the following drawbacks.

In method (2), vibration isolation is achieved by adding unnecessary equipment if vibrations do not occur, and this poses the problem of hindering the downsizing, cylindrical design, and cost reduction of machines and structures. be.

In method (2), two metal plates are bonded using a viscoelastic polymer material, so the adhesion between the metal plates is not necessarily sufficient, and deep drawability is generally poor. Since it does not pass through it, it has poor spot weldability, and furthermore, the operating temperature ranges from room temperature to about 120°C, which exceeds that range. 4
! Cannot be used in Maro.

The performance of all of the above-mentioned vibration-proof alloys developed by method (1), except flake graphite cast iron and ^l-Zn alloy, is significantly degraded due to residual stress caused by processing, welding, etc. On the other hand, flake graphite cast iron and At-Zn alloys have a problem in that processing, welding, etc. are difficult.

An object of the present invention is to provide a vibration-proof metal material that is free from the above-mentioned drawbacks and has excellent workability and formability.

(Means for solving problems) The gist of the present invention lies in the following vibration-proof metal materials.

■ A cladding material made by metal-bonding two types of metal materials with an acoustic impedance ratio of 2 = 1 or more for longitudinal waves or transverse waves, with one metal as the core material and the other metal material as laminate materials on the upper and lower surfaces of this core material. Anti-vibration metal material made of

(2) The vibration-proof metal material as described above, wherein the thickness of the core material is 60% or less of the total thickness of the cladding material.

■ A vibration-proof metal material consisting of a multilayer cladding material made by metal-bonding four or more layers of two types of metal materials with an acoustic impedance ratio of 2:1 or more for longitudinal waves or transverse waves.

(2) The vibration-proof metal material according to (1), (2) or (2) above, which has a junction material at the bonding interface of two types of metal materials.

The above-mentioned metal materials may be either pure metals or alloys. Combinations of metal materials that provide a ratio of acoustic impedance to longitudinal waves or transverse waves of 2:1 or more include aluminum and sea bream, and aluminum and stainless steel. Examples include steel, aluminum and copper, magnesium and titanium.

FIG. 1 is an explanatory view showing the structure of an example of the vibration-proof metal material of the present invention (invention (■)), in which (a) is a plate, and (a) is a tube. In FIGS. 1(a) and 1(c), 1 is a central material, and 2 is a laminate joined to both sides of the central material 1.

Invention (2) is the invention (2) in which the thickness of the core material is 60% or less of the total thickness of the cladding material, which makes it possible to weld and join the cladding material as a single piece of metal, as described later. Become a product.

The invention described in (■) involves the following steps when joining two types of metal materials:
Four or more layers are alternately stacked on top of each other.

In the invention (2), when two types of metal materials are joined, a layer of one or more other metal materials is interposed at the interface as a mediating material.

The purpose of interposing the intermediate material is to prevent hard and brittle intermetallic compounds or carbides that may precipitate at the joint depending on the combination of the two types of metal materials to be joined, which can significantly reduce the joint strength. For example, in the case of a combination of aluminum and carbon steel or aluminum and stainless steel, the former may cause precipitation of FaA 1, etc.
Also, the latter is N1Aj! The bonding performance may be significantly deteriorated due to the precipitation of such substances. On the other hand, for example, before rolling, a copper sheet with a thickness of about 50 μm to 2 ms is interposed between the two types of metal materials to be joined, and after rolling the sheet has a thickness of several tI1.
By forming a copper layer with a thickness of about 1 to 500 μm at the bonding interface, the above problems can be prevented.

(Function) The reason why the vibration-proof metal material of the present invention having the above-mentioned configuration has excellent vibration damping characteristics and good workability and formability is based on the following functions.

Table 1 shows the acoustic impedance of aluminum (8L) and steel.The acoustic impedance of Al to longitudinal waves is 16.9X10'kg/-Tomi・S, and that of sea bream is approximately 46X10''kg/■ Mushroom S. Therefore, the ratio of acoustic impedance to longitudinal waves of steel and Al is 2.7 for steel and ^ff1l.

The energy transfer coefficient of acoustic energy at the interface where Al and the sea bream are bonded is 15, as described below, that is, not all of the incident energy is reflected or transmitted, but the value is the ratio of the acoustic impedance of both materials. Depending on the
loss) occurs.

Figure 3 shows two adjacent materials with semi-infinite areas.
The acoustic energy transmitted through the interface of materials 1 and 2 is plotted on the horizontal axis with the ratio of the acoustic impedances of both materials (Z, /Z1, where Z and Z are the acoustic impedances of materials 1 and 2, respectively). "New Materials/New Metals and the Latest Manufacturing and Processing Technologies" 570 pages General Junjutsu Publishing 19
9B, published 2.29).

In the figure, material zl is Al, material 2. When considered as steel, the impedance ratio of sea bream to Al is 2.7, so the dashed line drawn perpendicularly from the 2.7 point on the horizontal axis intersects the curve representing the energy transfer coefficient at the 0.95 point. . That is, in this case, an energy loss of 5% occurs. This energy loss repeatedly acts on the longitudinal waves propagating through the vibration-proof metal material of the present invention, and the superimposed effect causes vibration attenuation.1 For example, when aluminum is used as the core material and carbon steel is bonded to both sides, In a plate having a thickness of IOIIM, a sound wave (longitudinal wave) incident in the thickness direction of the plate reciprocates within the plate approximately 300,000 times per second. Therefore, the bonding interface between aluminum and carbon steel is 1
If there is a 5% energy loss every time it passes,
Almost all energy is consumed in 1/10000 seconds.

As mentioned above, the energy loss at the interface between two different types of metals that are joined is due to the acoustic impedance ratio of 2.
: If it is less than 1, it will be 4% or less, and the vibration isolation property will be small (therefore, in the present invention, the acoustic impedance ratio is 2:]
It was decided to use the above metal 21111.

In invention (2), the thickness of the core material is set to be 60% or less of the total thickness of the cladding material, because when a certain member is assembled by welding using this cladding material, the thickness of the core material exceeds 60%. This is because welding becomes difficult.

Figure 4 is a diagram schematically showing an example of the joining state during welding, where (a) the total plate thickness is relatively thick, and (b) the core material 1 has a relatively thin layer thickness. Or, if the total plate thickness is relatively thin, as can be inferred from this figure, if the thickness of the core material 1 is too large (over 60%) of the total thickness, only the laminate material can be used. It is possible to obtain the necessary strength by welding, and if the ratio of the core material is low or the total plate thickness is thin, the effect of dilution of the weld metal by the core material will be reduced, so welding can be done as a single piece of metal. Welding is possible.

In order to manufacture the vibration-proof metal material of the present invention, any of the rolling method and other conventional methods for manufacturing cladding materials may be used depending on the two types of metal materials used.

(Example 1) An assembled slab having the structure shown in FIG. 5 was manufactured using pure aluminum and carbon steel having the chemical composition and dimensions shown in Table 2. In the figure, 4 is pure aluminum, 5 is carbon steel, a is column 16 m, and b is column 17@en. The joint surfaces of both pure aluminum and carbon steel are polished.

The acoustic impedance of the materials used was 16.9 x 10'kgI-''·s for pure aluminum and 46.
At 0×10′kg/m”·S, the acoustic impedance ratio of carbon steel and pure aluminum is 2.7.

After heating this assembled slab (thickness: 50mm, diameter: 1100mm, length: 1500mm) at 550°C for 3 hours, the reduction ratio was 5.
Rolled to a thickness of 10 mm, a radius of 1300 as, and a length of 500 mm.
A 0m-thick clad steel plate (vibration-proof metal material of the present invention) was used.

Regarding this steel plate, 20℃ of pure aluminum and carbon steel
We investigated the joint strength, acoustic effects against impact, and vibration damping status of the cantilever beam. Thickness 10 for comparison material
A carbon steel plate of mm was used.

The bonding strength was measured according to the shear strength test specified in JIS G 0601.

In measuring the acoustic effect against impact, as shown in Fig. 6, one piece of the clad steel plate and the comparative material were
A cube with a diameter of 00 mm and only one side open is made by welding and a falling object of a predetermined weight is allowed to fall naturally from a position 1 m directly above the center of side A, and a cube 1 m in front of the open side is made.
Impact sound was measured at position P.

The vibration damping condition of the cantilever beam is determined from the above-mentioned clad steel plate and comparative material: thickness 10mm, diameter 30m1, length 20〇-■
Cut out a test piece and fix one end in a vise.
Then, its vibration damping curve was measured.

As a result of the investigation, the bond strength between pure aluminum and carbon steel is 14
．． It had sufficient strength at 3 kgf/l.

Fig. 7 shows the measurement results of the acoustic effect against impact, and Fig. 8 shows the vibration damping state of the cantilever beam (Fig.

From FIG. 7 (acoustic effect on impact), it can be seen that the clad steel plate of the present invention has significantly lower impact noise than the carbon steel plate. Furthermore, as is clear from FIG. 8 (vibration damping situation with a cantilever beam), the time required for vibration damping was also significantly shorter in the clad steel plate 4 of the present invention (Fig. 4 (Q))).

(Example 2) The vibration-proof metal materials (examples of the present invention) shown in FIGS. 9(a) to (e) were produced using metal materials having the chemical components and acoustic impedance shown in Table 3, and the core material and The joint strength of the laminates and the acoustic effects against impact were investigated. In addition, the third
Numbers 1 to 5 in the table correspond to figures (a) to (e) in Figure 9, respectively, and in figures (a), (b1, and (d)), 11, 1, and ! Also 3 mm.

In figures (C) and (e), ! 5.12, I!
, , 14 and 1. are both 2-. In addition, in the present invention examples Na 1 and Na 4, a medium junction material was used (the 4th
(see table).

The bonding strength was measured using the same method as in Example 1.

The measurement of the acoustic effect on impact was also carried out under the same conditions as in Example I, except that the weight of the falling object was only 250 g.

The results of the investigation are shown in Table 4. As is clear from the table, the bonding strength of all of them showed satisfactory values, and the acoustic effects (impact sound) against impact were also observed for each of the comparative materials (listed in the right column of the table). ) showed a considerably lower value than that of

(Hereinafter, blank space) (Effects of the invention) The vibration-proof metal material of the present invention does not use a polymer material, so it has excellent heat resistance, good workability, and the layer thickness ratio of the core material and the laminated material can be made appropriate. This makes it possible to ensure good weldability.

[Brief explanation of drawings]

FIG. 1 is an explanatory view showing the structure of an example of the vibration-proof metal material of the present invention, in which (a) is a plate and (c) is a tube. FIG. 2 is a diagram showing the relationship between the tensile strength and vibration damping coefficient of a metal material. FIG. 3 is a diagram showing the relationship between the ratio of acoustic impedance of two materials and the energy transfer coefficient. FIG. 4 is a schematic diagram showing a joining situation during welding of the vibration-proof metal material of the present invention. FIG. 5 is an explanatory diagram showing the structure of an assembled slab for producing the vibration-proof metal material used in the example. FIG. 6 is an explanatory diagram of a method for measuring acoustic effects on impact. FIG. 7 is a diagram showing the measurement results of acoustic effects on impact. FIG. 8 is a diagram showing the results of an investigation of the vibration fiIi voice condition in a cantilever beam, in which (a) the comparison material and 0:I) the vibration-proof metal material of the present invention. FIG. 9 is a diagram showing the structure of the vibration-proof metal material used in the example.

Claims (4)

[Claims] (1) Two types of metal materials with an acoustic impedance ratio of 2:1 or more for longitudinal waves or transverse waves, one of which is used as a core material, and the other metal material is used as a laminate material to join the upper and lower surfaces of this core material. Anti-vibration metal material made of cladding material. (2) The vibration-proof metal material according to claim (1), wherein the thickness of the core material is 60% or less of the total thickness of the cladding material. (3) A vibration-proofing metal material consisting of a multilayer cladding material in which four or more layers of two types of metal materials having an acoustic impedance ratio for longitudinal waves or transverse waves of 2:1 or more are alternately stacked and metal-bonded. (4) The vibration-proof metal material according to claim (1), (2) or (3), further comprising a junction material at the bonding interface between the two types of metal materials.