KR101191772B1 - Menufacturing method of aluminum alloy for automobile handle - Google Patents

Abstract

The present invention relates to a method for producing an aluminum alloy composition for automobile handles, Mg: 2.0 to 2.3% by weight, Zn: 0.01 to 0.15% by weight, Mn: 0.4 to 0.5% by weight, Ti: 0.01 to 0.05% by weight, Fe: 0.5 to 0.7 wt%, Si: 0.2 to 0.3 wt%, Cu: 0.01 to 0.15 wt%, Ni: 0.007 to 0.01 wt%, Cr: 0.01 to 0.15 wt%, Sn: 0.007 to 0.01 wt%, Pb: 0.007 to A first step of melting the metal having a composition of 0.01% by weight and the balance Al at 7 to 8 hours at a temperature of 650 ° C. to 750 ° C .; It may be characterized in that it comprises a second step of removing, and a third step of calming the molten metal for 5 to 10 minutes. The aluminum alloy for automobile handles manufactured according to the present invention has excellent strength and elongation, and is easy to mold, and has strong strength and light weight as compared to existing aluminum alloys.

Description

Manufacturing method of aluminum alloy composition for automobile steering wheel {MENUFACTURING METHOD OF ALUMINUM ALLOY FOR AUTOMOBILE HANDLE}

The present invention relates to a method of manufacturing an aluminum alloy composition for automobile handles, and more particularly, to an Al-Mg alloy having excellent strength and elongation among existing aluminum alloys as a model, and excellent in strength and elongation, and easy to mold. The present invention relates to a method for producing an aluminum alloy composition for automobile steering wheels having a stronger strength and lighter weight than an aluminum alloy.

In general, the aluminum main alloy has been widely spotlighted for various transportation equipment, aircraft parts, defense parts, and industrial parts because of its light weight, and as aerospace parts, housing, cylinder head and piston, turbine impeller, and missile fin (Fin) ), It is used for manufacturing various parts such as landing gear housing and cooling fan.

In particular, in recent years, as it is used as an automotive component, it is possible to expect an improvement in fuel efficiency by reducing the weight of the vehicle, and thus an aluminum main alloy is applied to various parts such as engine parts, suspensions, wheels, handles, and the like.

However, the aluminum alloy produced by the casting method can be suitably used for parts having a complicated shape compared to the workpiece, but has a disadvantage of being inadequate for use in parts requiring high ductility due to low ductility.

For example, the most ductile alloy among aluminum main alloys is aluminum-magnesium alloy, and the representative commercially available high ductility aluminum alloys include AC7A (KS standard), 513.0 (ASTM standard) and 515.0 (ASTM standard). As shown in Table 1 below, they have a low elongation.

TABLE 1

(The ingredient content in Table 1 is all in weight percent)

As shown in Table 1, these high ductility aluminum main alloys have a tensile strength and elongation of AC7A: 210 MPa, 12%; 513.0: 276 MPa (yield strength: 152 MPa), 10%; The value of 515.0: 283 MPa, 10%, but not suitable for automotive parts requiring sufficient ductility.

This is because the elongation must be 16% or more to ensure maximum safety of the occupants because the plastic deformation without breaking the material in the event of a vehicle crash.

The invention of the prior art Patent No. 10-0703130 (name of the invention: a non-heat treatment type high ductility aluminum main alloy and a manufacturing method thereof) is, by weight, Mg: 4.0 ~ 4.8%, Zn: 0.5 ~ 0.7%, Mn : 0.5% or less, Ti: 0.25% or less, Fe: 0.2% or less, Si: 0.2% or less, Cu: 0.1% or less, Be: 0.005% or less, and the balance Al, tensile strength of 260 ~ 273MPa, yield strength even in casting state It has 110-123 MPa and elongation 16-23%.

The prior art has a relatively high specific gravity of Mg and Zn in the composition, and even though the elongation is high, there is a problem that it is difficult to use as a material for automobile parts due to low formability and strength.

Therefore, an object of the present invention is to solve the problems of the prior art as described above, modeled on the Al-Mg alloy excellent in strength and elongation among the general aluminum alloy, and excellent in strength and elongation, easy molding, The present invention provides a method for producing an aluminum alloy composition for automobile handles, which is stronger and lighter than conventional aluminum alloys.

According to a feature of the present invention for achieving the above object, the manufacturing method of the aluminum alloy composition for automobile handle of the present invention is Mg: 2.0 to 2.3% by weight, Zn: 0.01 to 0.15% by weight, Mn: 0.4 to 0.5 % By weight, Ti: 0.01% to 0.05%, Fe: 0.5% to 0.7%, Si: 0.2% to 0.3%, Cu: 0.01% to 0.15%, Ni: 0.007% to 0.01%, Cr: 0.01% to 0.15% , A first step of melting a metal having a composition of Sn: 0.007 to 0.01% by weight, Pb: 0.007 to 0.01% by weight and the balance Al at a temperature of 650 to 750 ° C for 7 to 8 hours,
A second step of removing the gas in the molten metal by bubbling the molten metal formed by the melting with argon gas for 5 to 15 minutes;
It characterized in that it comprises a third step of calming the molten metal for 5 to 10 minutes.

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The manufacturing method of the aluminum alloy composition for automobile handles according to the present invention is easy to be molded while having excellent strength and elongation so as to be suitable for use as an automotive parts material by modeling an aluminum alloy having excellent strength and elongation among existing aluminum alloys. And, compared to the existing aluminum alloy has a strong strength and light weight has the effect of providing an aluminum alloy for a steering wheel.

1 is a flowchart illustrating a method of manufacturing an aluminum alloy composition for a vehicle steering wheel according to the present invention.

Hereinafter, a preferred embodiment according to the manufacturing method of the aluminum alloy composition for automobile handles according to the present invention will be described in detail.

The method of manufacturing an aluminum alloy composition for a car handle of the present invention is first, Mg, Zn, Mn, Ti, Fe, Si, Cu, Ni, Cr, Sn, Pb and Al to remove impurities for the composition of the aluminum alloy for a car handle Prepared.

The aluminum alloy composition for a car handle is Mg: 2.0 to 2.3% by weight, Zn: 0.01 to 0.15% by weight, Mn: 0.4 to 0.5% by weight, Ti: 0.01 to 0.05% by weight, Fe: 0.5 to 0.7% by weight, Si 0.2 to 0.3% by weight, Cu: 0.01 to 0.15% by weight, Ni: 0.007 to 0.01% by weight, Cr: 0.01 to 0.15% by weight, Sn: 0.007 to 0.01% by weight, Pb: 0.007 to 0.01% by weight, and the balance Al It is configured to include.

Mg is added to the aluminum alloy to affect the corrosion resistance and strength.

In the aluminum alloy composition, when the composition ratio of Mg is 2.0 to 2.3% by weight, which is lower than 4.0 to 4.8% by weight of the prior art, corrosion resistance and strength are lowered.

On the other hand, the elongation is increased, the flowability of the molten metal is improved and the castability is increased.

When the composition ratio of Mg is less than 2.0% by weight, the strength is drastically decreased. When the composition ratio of Mg is more than 2.3% by weight, the strength is improved but the elongation is rapidly decreased. Therefore, the composition ratio of Mg is preferably 2.0 to 2.3% by weight. .

Zn is added to the aluminum alloy, affecting the corrosion resistance and strength.

In the aluminum alloy composition, when the composition ratio of Zn is 0.01 to 0.15% by weight, which is reduced from 0.5 to 0.7% by weight of the prior art, corrosion resistance and strength are increased.

When the Zn is added in an excessive amount, since corrosion resistance and strength are reduced, it is preferable to make the composition ratio 0.01 to 0.15% by weight.

When Zn is added to Cu or Mg simultaneously with heat treatment, the corrosion resistance and strength are improved.

Mn does not have a great influence on the aluminum alloy, but is added in order to cancel out the negative effect of Fe addition, and the composition ratio is preferably 0.4 to 0.5% by weight.

Ti is added to the aluminum alloy to refine the crystal grains and improve heat resistance and solubility.

However, when Ti is added in an excessive amount, segregation occurs and mechanical properties are lowered, so that the composition ratio is preferably 0.01 to 0.05% by weight.

Fe is added to the aluminum alloy to prevent the sintering of the mold and the molten metal during the melting and casting process, and serves to improve the strength.

In the aluminum alloy composition, when the composition ratio of Fe is 0.5 to 0.7% by weight, which is increased from 0.23% by weight of the prior art, corrosion resistance and strength are increased.

The composition ratio of Fe is higher than the composition ratio of the prior art in order to prevent the decrease in strength due to the decrease in the composition ratio of Mg, and in order to maintain the elongation of the prior art, the composition ratio is preferably 0.5 to 0.7% by weight. Do.

Si is added to the aluminum alloy to improve the flowability of the molten metal, and serves to lower the melting point of the aluminum alloy.

At this time, by lowering the melting point to reduce the gas absorption to reduce the occurrence of swelling, as well as to prevent hot cracking and to enable the production of complex castings.

It is preferable that the composition ratio of said Si shall be 0.2 to 0.3 weight%.

Cu is added to the aluminum alloy, and serves to improve the strength.

When the Cu is added simultaneously with Si, the elongation is greatly reduced, so that the composition ratio is preferably 0.01 to 0.15% by weight.

When Ni is excessively added to the aluminum alloy, the strength is lowered, so it is preferable to make the composition ratio 0.007 to 0.01 wt%.

When Cr is excessively added to the aluminum alloy, the strength of the material is lowered, so the composition ratio is preferably 0.01 to 0.15% by weight.

When Sn is excessively added to the aluminum alloy, the strength of the material is lowered. Therefore, the composition ratio is preferably 0.007 to 0.01 wt%.

When Pb is excessively added to the aluminum alloy, the strength of the material is lowered, so the composition ratio is preferably 0.007 to 0.01 wt%.

Hereinafter, the manufacturing method of the aluminum alloy for automobile handles which has the composition as mentioned above is demonstrated.

The manufacturing method, the first step (S10) of melting the metal having the above-described composition at a temperature of 650 ~ 750 ℃ 7-8 hours, the second step (S20) of removing the gas in the melt formed by the melting, the molten metal It characterized in that it comprises a third step (S30) to calm 5 to 10 minutes.

First, a first step S10 of melting the metal having the above-described composition at a temperature of 650 to 750 ° C for 7 to 8 hours is performed.

That is, Mg: 2.0 to 2.3% by weight, Zn: 0.01 to 0.15% by weight, Mn: 0.4 to 0.5% by weight, Ti: 0.01 to 0.05% by weight, Fe: 0.5 to 0.7% by weight, Si: 0.2 to 0.3% by weight, Aluminum for automobile steering wheels including Cu: 0.01 to 0.15% by weight, Ni: 0.007 to 0.01% by weight, Cr: 0.01 to 0.15% by weight, Sn: 0.007 to 0.01% by weight, Pb: 0.007 to 0.01% by weight, and balance Al The alloy composition is melted at a temperature of 650 to 750 ° C for 7 to 8 hours.

When the melting temperature is more than 750 ℃, the concentration of the gas contained in the molten metal increases to reduce the elongation of the aluminum alloy, when the melting temperature is less than 650 ℃ to reduce the fluidity of the molten aluminum alloy composition for a car steering wheel is obtained. It becomes impossible.

Therefore, it is preferable that the said melting temperature shall be 650-750 degreeC.

Next, a second step (S20) of removing the gas in the molten metal formed by the melting proceeds.

In the second step (S20), the molten gas is bubbled with argon gas for 5 to 15 minutes to remove the gas in the molten metal.

When the bubbling time is 5 minutes or less, the gas in the molten metal is not completely removed, so that the elongation of the aluminum alloy does not reach a target value. When the bubbling time is 15 minutes or more, the effect of degassing does not increase any more. It is preferable to set it as 5 to 15 minutes.

Subsequently, a third step S30 of calming the molten metal for 5 to 10 minutes is performed.

The third step (S30) is to stabilize the molten metal, to equalize the chemical composition and temperature, the implementation time is preferably 5 minutes to 10 minutes.

On the other hand, the aluminum alloy composition for automobile handles formed through the above steps is introduced into the preheated handle mold to be molded to manufacture the automobile handles.

Table 1 below shows the results of the strength test of the steering wheel formed of the aluminum alloy composition for automobile handles according to an embodiment of the present invention.

Load Load-displacement A 400.000 Kg.f 117.400 mm B 500.500 Kg.f 77.780 mm C 397.900 Kg.f 87.880 mm

The test was conducted at a temperature of 24 ° C. and a humidity of 50%.

The test handle was mounted in the same manner as that normally mounted on the vehicle, and the upper corners at the 12 o'clock, 3 o'clock, and 6 o'clock directions were shown as A, B, and C at the center of the handle, respectively.

As shown in Table 1, A is deformed to 117.400 mm at a maximum load of 400.000 Kg.f.

B deforms up to 77.780 mm at a maximum load of 500.500 Kg.f.

C deforms to 87.880 mm at a maximum load of 397.900 Kg.f.

The present invention is not limited to the above-described specific preferred embodiments, and various modifications can be made by those skilled in the art without departing from the gist of the present invention as claimed in the claims. Of course, such changes will fall within the scope of the claims.

Claims (3)

Mg: 2.0-2.3 wt%, Zn: 0.01-0.15 wt%, Mn: 0.4-0.5 wt%, Ti: 0.01-0.05 wt%, Fe: 0.5-0.7 wt%, Si: 0.2-0.3 wt%, Cu: Metals having a composition of 0.01 to 0.15% by weight, Ni: 0.007 to 0.01% by weight, Cr: 0.01 to 0.15% by weight, Sn: 0.007 to 0.01% by weight, Pb: 0.007 to 0.01% by weight, and the balance Al are 650 ° C to 750 ° C. A first step S10 of melting at a temperature of 7 to 8 hours;
A second step (S20) of removing the gas in the molten metal by bubbling the molten metal formed by the melting with argon gas for 5 to 15 minutes;
The third step (S30) to calm the molten metal for 5 to 10 minutes; Manufacturing method of the aluminum alloy composition for a vehicle handle, comprising a.


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