KR101488288B1 - Vibration damping aluminum alloy - Google Patents

Abstract

The present invention relates to a vibration damping type aluminum alloy, which comprises 38 to 43% by weight of zinc (Zn) relative to the weight of the entire alloy, and has an excellent vibration damping effect as compared with the conventional aluminum alloy. To a vibration damping type aluminum alloy capable of improving the noise vibration (NVH) quality of a vehicle without design or modification.

Description

[0001] Vibration damping aluminum alloy [0002]

The present invention relates to a vibration damping type aluminum alloy, more particularly, by controlling a composition ratio of an aluminum alloy to further improve a vibration damping function of the alloy itself, thereby reducing vibrations and noise generated in the timing chain cover, To an improved vibration damping type aluminum alloy.

In order to meet the standards of the consumers who want to purchase the car, the automobile industry competes for the development of technologies such as reduction of vibration, noise, ride comfort and fuel consumption of the automobile. Especially, the vibration and noise of the automobile, The importance of which is increasing.

The vibration and noise of a car can be divided into two types, that is, an external condition and an internal condition. In particular, the noise from the interior of the vehicle occurs mainly when the engine and driveline are operating. The portion where vibration and noise are mainly generated in the engine is a portion including a timing chain and a timing gear. Generally, the timing chain is provided with a timing chain on one side of an engine constituting an automobile. The timing chain functions to connect a timing gear mounted on a crankshaft and a timing gear of a camshaft.

Meanwhile, the reciprocating linear motion of the piston generated by the engine is converted into rotational motion through the crankshaft. The timing chain includes an intake stroke for receiving the air and the fuel sucked into the engine by allowing the camshaft to move the rotational movement properly, A compression stroke for compressing the air and the fuel, an explosion stroke for exploding the compressed air and the fuel, and an exhaust stroke for discharging the gas burned by the explosion to the outside.

1 is a view showing a vehicle timing chain cover. In order to protect the conventional timing chain, a metallic timing chain cover 100 is used. The timing chain cover 100 causes vibrations generated in the engine to vibrate the timing chain cover 100, thereby causing vibration and noise in the timing chain cover 100. [ In addition, since the wide and thin shape of the timing chain cover 100 can not effectively block the transmission or spread of vibration and noise generated in the timing chain itself, the quality of the noise (vibration, vibration, and harshness) .

Also, since the timing chain is connected to the oil pump of the engine, there is a disadvantage that the vibration and noise generated in the engine oil pump diffuse to the outside of the vehicle through the timing chain cover 100 through the timing chain. In addition, the vibration and the noise of the engine combustion chamber are also transmitted to the timing chain through the crankshaft, and the vibration and the combustion noise are transmitted to the outside of the automobile through the timing chain cover 100.

In the conventional timing chain cover 100, an aluminum alloy such as ADC10, ADC12, and ADC12Z is manufactured using a die casting process (high pressure die casting process, HPDC). ADC alloys are widely used for die casting And the mechanical properties are excellent. However, the alloy itself has a limitation in that it can not improve the quality of the noise vibration (NVH) by suppressing vibration and noise of the timing chain cover.

In order to cope with this problem, there is a method of increasing the thickness of the timing chain cover 100 itself to reduce the amount of noise emitted or adding a lip to the fragile portion. However, if the thickness is increased, And there is a problem in that when the lip is added, interference with peripheral components occurs.

[Patent Document 1] Published Unexamined Patent Application No. 10-2014-0015932 (2014. 02. 07; Casting alloy composition) [Patent Document 2] Published Unexamined Patent Application No. 10-2014-0025599 (April, 2014, high strength aluminum alloy material and manufacturing method thereof) [Patent Document 3] Published Japanese Translation of PCT Application No. 10-2011-0139926 (Dec. 30, 2011: Aluminum alloy composition for cylinder head)

It is an object of the present invention to solve the above problems and to provide a vibration damping effect in an alloy itself by controlling a composition ratio of zinc (Zn) and silicon (Si) And an object of the present invention is to provide a vibration damping type aluminum alloy capable of improving vibration (NVH) quality.

In order to achieve the above object, the vibration damping type aluminum alloy according to the present invention comprises 38 to 43% by weight of zinc (Zn) based on the weight of the entire alloy.

The vibration damping aluminum alloy may further include at least one component selected from the group consisting of silicon (Si), copper (Cu), iron (Fe), manganese (Mn), and titanium (Ti).

In this case, when the vibration damping aluminum alloy further includes silicon (Si), copper (Cu), iron (Fe), manganese (Mn), and titanium (Ti) Si is not less than 0 and not more than 4 wt%, copper (Cu) is not less than 2 to 4 wt%, iron (Fe) is more than 0 and not more than 1 wt%, manganese (Mn) More preferably more than 0 and 0.3% by weight or less.

In one embodiment of the present invention, the vibration attenuating aluminum alloy preferably further comprises silicon (Si), copper (Cu), and iron (Fe), wherein the zinc (Zn) It is more preferable that silicon (Si) is 0.4% by weight, copper (Cu) is 3.0% by weight and iron (Fe) is 0.3% by weight.

On the other hand, the vibration damping type aluminum alloy can be used for a timing chain cover of an automobile.

The effect of the present invention having the above structure is advantageous in that the composition of the conventional aluminum alloy is modified to exhibit the vibration damping effect in the alloy itself. At this time, when the alloy is applied to the automotive timing chain cover 100, there is an advantage that the quality of the NVH of the automobile can be improved without changing the design.

In addition, since the damping ratio of the alloy further increases as the temperature increases, the ability of the vibration-damping aluminum alloy itself to absorb vibration is improved, which is advantageous for a high-temperature engine room environment.

In addition, since manufacturing and processing are performed in almost the same manufacturing process as conventional aluminum alloys, there is no need for additional processing cost, and there is no restriction on the alloy design, so that the degree of freedom of design can be improved.

In addition, the tensile strength of the vibration damping type aluminum alloy is increased as compared with the conventional aluminum alloy, so that the durability of the vibration damping type aluminum alloy is improved. In addition, since the price of the vibration damping aluminum alloy of the present invention is lower than that of the conventional aluminum alloy, it is advantageous in terms of economy and it is possible to reduce the weight (50%) of the conventional cast iron parts, And fuel economy improvement can be expected.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a view of a timing chain cover of a motor vehicle.
FIG. 2 is the Al-Zn phase diagram of aluminum (Al) -zinc (Zn).
3 is a schematic view showing the principle of vibration damping effect at an interface.
4 is a view showing a spinodal line of the phase equilibrium diagram
FIG. 5 is a graph showing a comparison of NVH quality when the timing chain cover 100 prepared by applying the components of the embodiment and the comparative example shown in Table 3 is applied to an actual vehicle.
6 is a microstructure photograph of an aluminum alloy (Al-40% Zn).

The terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms and the inventor may appropriately define the concept of the term in order to best describe its invention It should be construed as meaning and concept consistent with the technical idea of the present invention. Therefore, the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and do not represent all the technical ideas of the present invention. Therefore, It should be understood that variations can be made.

The present invention relates to an aluminum alloy having improved vibration and noise reducing function, and the present invention will be described in detail below with reference to the accompanying tables and drawings.

division Zn (% by weight) Si (% by weight) Cu (% by weight) Fe (% by weight) Mn (% by weight) Ti (% by weight) Al (% by weight) Invention 38 ~ 43 4.0 or less 2.0 to 4.0 1.0 or less 0.5 or less 0.3 or less Remainder Conventional 0.1 or less 9.6-12.0 1.5 to 3.5 0.6 to 1.0 0.5 or less 0.3 or less all

Table 1 above shows a comparison between a composition of a vibration-attenuating aluminum alloy and a conventional aluminum alloy composition as one embodiment of the present invention. As shown in the above table, the greatest difference between the conventional aluminum alloy and the vibration damping type aluminum alloy of the present invention is the content of zinc (Zn). The conventional aluminum alloy contains a small amount of 0.1 wt% or less of zinc (Zn) based on the total weight, but the vibration damping type aluminum alloy of the present invention is characterized by containing 38 to 43 wt% of zinc (Zn) , And the zinc having the above composition forms a zinc (Zn) precipitate phase in the aluminum alloy, which will be described in detail below.

2 shows the phase diagram of aluminum (Al) -Zn (Zn). As shown in the phase equilibrium diagram, when the total weight of zinc (Zn) is 32.4 to 77.7% by weight Eutectoid transformation occurs at 277 ° C. That is, from 277 ° C, a zinc (Zn) precipitate phase is formed in the aluminum (Al) matrix texture, and two phases causing interfacial friction appear on the microstructure.

FIG. 3 is a schematic view showing the principle of vibration damping effect at the interface. As described above, the precipitation phase 300 of zinc (Zn) is formed in the base structure 200 of aluminum (Al) by the vacancy transformation, so that the interface 400 is generated. When the vibration energy is transmitted to the aluminum alloy , Part of the vibration energy is converted into friction energy by the interface (400), and vibration is reduced.

Particularly, FIG. 4 is a view showing a spinodal line of the phase equilibrium diagram. When the content of zinc is 38 to 70 wt% based on the total weight, zinc (Zn) is decomposed due to spinodal decomposition, Phase separation occurs even in the precipitation phase, and an interface is further generated inside the zinc (Zn) precipitation phase.

That is, an additional vibration damping effect is exhibited not only by the base structure 200 of aluminum (Al) and the interface 400 between the precipitation phases of zinc (Zn) but also by the internal interface of the zinc (Zn) precipitation phase.

Therefore, in consideration of the area of the interface where the vacancy change and the spinodal decomposition occur at 277 ° C and the increase in the alloy and the vibration damping effect, the zinc (Zn) It is preferable that it is contained in an amount of 38% by weight or more based on the weight of the alloy.

At this time, the vibration damping effect of the aluminum alloy containing zinc increases as the area of the interface 400 composed of the base structure 200 of aluminum (Al) and the precipitation image 300 of zinc (Zn) becomes wider, As Zn content increases, the vibration damping effect also increases. However, since zinc (Zn) is heavier and more expensive than aluminum (Al), the weight and material ratio of the alloy increase as the content of zinc (Zn) It is preferable that zinc is contained in an amount of 43 wt% or less based on the total weight of the alloy.

The vibration damping type aluminum alloy according to the present invention may further comprise at least one member selected from the group consisting of silicon (Si), copper (Cu), iron (Fe), manganese (Mn) and titanium It is preferable that the vibration damping type aluminum alloy includes all of silicon (Si), copper (Cu), iron (Fe), manganese (Mn) and titanium (Ti) Si is not less than 0 and not more than 4 wt%, copper (Cu) is not less than 2 to 4 wt%, iron (Fe) is more than 0 and not more than 1 wt%, manganese (Mn) More preferably more than 0 and 0.3% by weight or less.

Specifically, the silicon (Si) is added to the alloy since it plays a role in improving the fluidity of the molten alloy in the casting of the aluminum alloy. When silicon (Si) is added to an aluminum alloy, primary silicon is formed in the microstructure of the alloy, and the silicon (Si) is strong and Brittleness particles are formed on the microstructure There is an advantage that the wear resistance of the alloy can be improved. However, silicon (Si) acts to lower other physical properties of the alloy.

division Composition of aluminum alloy Tensile Strength (MPa) Elongation (%) Vibration damping ratio (%) Example 1 Al-40Zn-3.0Cu-0.4Si-0.3Fe 357 2.7 5.67 Comparative Example 1 Al-40Zn-3.5Cu-4.2Si-0.3Mn 240 ~ 260 1.5 to 2 - Comparative Example 2 Al-40Zn-3.0Cu-8.0Si-0.3Mn 200 ~ 220 1 to 1.2 4.87

Table 2 is a table showing tensile strength, elongation and vibration damping ratio according to the content of silicon (Si). As can be seen from the above table, tensile strength, elongation and vibration damping ratio are decreased as the content of silicon (Si) increases. As described above, silicon (Si) has a disadvantage of deteriorating the physical properties of alloys as a structural material and also lowering the vibration damping effect, and it is preferable that silicon (Si) is contained in an amount of more than 0 wt.

The copper (Cu) reacts with aluminum (Al) in the aluminum alloy to form a CuAl ₂ compound, thereby improving the strength of the aluminum alloy. In view of the effect of improving the strength of the alloy, . However, the brittleness and the specific gravity are increased when the excess amount is added to reduce the castability, so that it is preferable that the brittleness and the specific gravity are included in an amount of 4 wt% or less based on the total weight of the alloy.

In addition, iron (Fe) is added to prevent the burning of the alloy and the mold at the time of manufacturing the alloy by a die casting method. The added iron (Fe) forms an intermetallic compound in the aluminum alloy, The mechanical properties such as elongation and tensile strength decrease are rapidly reduced, and it is preferable that the content is in the range of more than 0 and 1 weight% with respect to the weight of the whole alloy.

The manganese (Mn) is added to suppress the deterioration of the mechanical properties caused by the iron (Fe) as described above. It is preferable that the manganese (Mn) is contained in an amount of more than 0 to 0.5 wt% Do.

Titanium (Ti) is added because it improves mechanical properties through grain refinement in an aluminum alloy. It is preferable that titanium (Ti) is contained in an amount of more than 0 to 0.3% by weight based on the weight of the entire alloy such as a conventional aluminum alloy.

The other impurities are preferably contained in an amount of 0.1 wt% or less based on the weight of the entire alloy so as not to deteriorate the physical properties of the alloy.

division Zn (% by weight) Si (% by weight) Cu (% by weight) Fe (% by weight) Mn (% by weight) Ti (% by weight) Al (% by weight) Example 1 40 0.4 3.0 0.3 - - Remainder Comparative Example 3 - 11.0 2.5 0.6 0.3 - Remainder

Table 3 shows that zinc (Zn) is contained in an amount of 0.4 wt% of silicon (Si), 3.0 wt% of copper (Cu) and 0.3 wt% of iron (Fe) And a comparison between a vibration attenuating type aluminum alloy and a conventional aluminum alloy.

High purity aluminum (Al) and zinc (Zn) were used to test the vibration damping effect and a master alloy containing silicon (Si) and copper (Cu) was used.

First, in order to remove hydrogen gas in the alloy, argon (Ar) gas was blown into the degassing apparatus for 5 minutes to perform degassing treatment.

The temperature of the melting furnace was maintained at a higher temperature of 700 ° C because the melting point of the alloy was about 580 ° C, and the injection temperature of the die casting machine for manufacturing the timing chain cover 100 was set at 680 ° C. The timing chain cover (100) mold was manufactured using a timing chain cover (100) mold which is mass-produced by a conventional automobile company, and a conventional die casting machine was used for casting. In addition, as a condition for injection of the finished product, injection was performed at a low speed of 0.5 m / s and a high speed of 3.0 m / s, and the high speed position was set at 475 mm.

The timing chain cover 100 using the vibration attenuating aluminum alloy fabricated as described above was manufactured through a conventional mass production line, and the engine was constituted by other components including an oil pump which is a conventional mass production component. FIG. 4 shows the result of applying the engine manufactured as described above to the actual vehicle and evaluating the quality of the noise vibration (NVH).

FIG. 5 is a graph comparing the noise vibration (NVH) of the actual vehicle with the timing chain cover 100 manufactured by applying the components shown in Table 3 and Comparative Example. Except for the component related parts, the manufacturing and machining were made in the same manner as the existing mass production method, and the measurement was carried out in an actual vehicle and measured outside the RH 50 cm in the No load Sweep. As a result, It was confirmed that the average noise of 1.0 dB was reduced in the 1.4 to 5 kHz band.

6 is a microstructure photograph of an aluminum alloy (Al-40% Zn). When zinc (Zn) is 40% by weight based on the total weight of the alloy, precipitation of zinc (Zn) Phase 300 is formed so that the interface 400 is generated so that a part of the vibration energy is converted into friction energy by the interface and disappears to reduce vibration and noise.

division Tensile Strength (MPa) Elongation (%) Vibration damping ratio (%) Example 1 357 2.7 5.67 Comparative Example 3 227 1.6 3.94

As shown in the table, the vibration damping type aluminum alloy according to the present invention is superior to the conventional aluminum alloy in vibration damping type aluminum alloy according to the present invention. Not only the decay rate but also the physical properties such as tensile strength and elongation are increased.

As described above, the present invention provides a vibration damping type aluminum alloy which exhibits a vibration damping effect in the alloy itself and can improve the quality of a vehicle's noise vibration (NVH) when applied to an automotive timing chain cover (100).

Although the present invention has been described in connection with the specific embodiments of the present invention, it is to be understood that the present invention is not limited thereto. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims and their equivalents. Various modifications and variations are possible.

100: Timing chain cover
200: Base structure of aluminum (Al)
300: precipitation phase of zinc (Zn)
400: interface

Claims (6)

Compared to the weight of the entire aluminum alloy,
Wherein the aluminum alloy comprises 40% by weight of zinc (Zn), 0.4% by weight of silicon (Si), 3.0% by weight of copper (Cu) and 0.3% by weight of iron (Fe) .
The method according to claim 1,
Wherein the aluminum alloy further comprises manganese (Mn) and titanium (Ti).
delete delete delete 3. The method according to claim 1 or 2,
Wherein the vibration attenuating aluminum alloy is used for a timing chain cover of an automobile.

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