KR20140061166A - Almgsi based aluminum alloy excellent in machinability, method of manufacturing the same and parts of an automobile manufactured from the same - Google Patents

Abstract

The present invention relates to an AlMgSi-based aluminum alloy including: 1.0-1.4% by weight of Si; 0.07-0.85% by weight of Mg; 0.8-1.20% by weight of Sn; 0.01-0.4% by weight of Mn; 0.001-0.50% by weight of Fe; 0.01-0.10% by weight of Cu; 0.01-0.25%% by weight of Cr; 0.01-0.20% by weight of Zn; and the rest of unavoidable impurities.

Description

TECHNICAL FIELD [0001] The present invention relates to an AlMgSi-based aluminum alloy having a high porosity, a method for manufacturing the same, and an automobile part manufactured from the AlMgSi-based aluminum alloy,

The present invention relates to an AlMgSi-based aluminum alloy having a high porosity, a method for producing the same, and an automobile part manufactured therefrom. More specifically, the present invention relates to an AlMgSi-based aluminum alloy, which improves workability of an aluminum alloy, suppresses burrs, minimizes the possibility of machining tools, reduces processing cycle time, A1 The present invention relates to an AlMgSi-based aluminum alloy which can be improved, a manufacturing method thereof, and an automobile part manufactured therefrom.

The pump housing of ABS (anti-lock breaking system) or ESC (electronic stability control) is mainly composed of 6000-series aluminum alloy.

However, alloys for 6000 series aluminum alloys generally have a long production of chips, which may cause the alloy to dry on the tool during machining, or increase the load on the tool during machining, which may increase the machining speed. And burrs may be formed on the surface of the processed product to lower the quality of the processed product.

Therefore, there is a need to develop an aluminum alloy technology that can improve processability through improvement of chip generation, minimize processing cycle time and improve the quality of machined parts.

In this regard, Korean Patent Publication No. 2008-0017374 (published on Mar. 26, 2008, title: Aluminum alloy) is an aluminum alloy containing 4.5-6.5 wt% magnesium, 1.0-3.0 wt% At least one rare earth metal, at most 0.2% by weight of iron and the remainder being aluminum < RTI ID = 0.0 > And an aluminum alloy.

An object of the present invention is to provide an AlMgSi-based aluminum alloy having improved mechanical properties and processability.

Another object of the present invention is to provide an AlMgSi-based aluminum alloy which improves the quality of an automobile part by preventing machining cycle time from being reduced due to processability and not causing defects such as burrs in final products.

It is still another object of the present invention to provide a method for manufacturing the AlMgSi-based aluminum alloy and an automotive part manufactured from the method.

In one aspect of the present invention, an AlMgSi-based aluminum alloy is an AlMgSi-based aluminum alloy containing 1.0 to 1.4% by weight of silicon (Si), 0.70 to 0.85% by weight of magnesium (Mg) 0.01-0.4 wt% of manganese (Mn), 0.001-0.50 wt% of iron (Fe), 0.01-0.10 wt% of copper (Cu), 0.01-0.25 wt% of chromium (Cr) -0.20% by weight, and inevitable impurities of the balance and aluminum (Al).

The content of manganese (Mn) may be 0.01-0.35 wt%.

The inevitable impurities may be 0.01-0.05 wt% and the total sum may be 0.05-0.15 wt%.

A method for producing an AlMgSi-based aluminum alloy according to another aspect of the present invention is a method for producing an AlMgSi-based aluminum alloy comprising 1.0-1.4 wt% of silicon (Si), 0.70-0.85 wt% of magnesium (Mg), 0.8-1.20 wt% of tin (Sn) (Cr) 0.01-0.25 wt.%, Zinc (Zn) 0.01-0.20 wt.%, And unavoidable impurities and residual amount of Comprising the steps of: preparing a composition for an AlMgSi-based aluminum alloy containing aluminum (Al) through a casting process as a billet; And subjecting the prepared billet to homogenization heat treatment, extrusion, stretching and aging heat treatment.

An automotive part, which is another aspect of the present invention, can be made of the AlMgSi-based aluminum alloy.

According to the embodiment of the present invention, an AlMgSi-based aluminum alloy improved in mechanical properties and workability can be provided. In addition, it is possible to provide an AlMgSi-based aluminum alloy improved in surface quality by preventing machining cycle time from being reduced and defects such as burrs being not generated in the finally manufactured article.

An AlMgSi-based aluminum alloy which is one aspect of the present invention is a AlMgSi-based aluminum alloy which contains 1.0-1.4 wt% of silicon (Si), 0.70-0.85 wt% of magnesium (Mg), 0.8-1.2 wt% of tin (Cr) 0.01-0.25 wt%, zinc (Zn) 0.01-0.20 wt%, and inevitable (Mn) 0.01-0.4 wt% Impurities and residual aluminum (Al).

Hereinafter, each element in the AlMgSi-based aluminum alloy of the present invention will be described in detail.

The amount of silicon in the AlMgSi-based aluminum alloy may be 1.0-1.4 wt%, preferably 1.2-1.4 wt%, more preferably 1.2-1.3 wt%, and most preferably 1.20-1.25 wt%. If it is contained in an amount less than 1.0% by weight, the hardness of the alloy is lowered. When the content exceeds 1.4% by weight, the casting speed is lowered due to the high alloy in producing the cast billet, The extrusion speed is lowered and the surface quality is lowered. In addition, there arises a problem that the amount of tool wear is increased due to an increase in hardness value due to excessive Excess-Si effect.

In the AlMgSi-based aluminum alloy, magnesium reacts with silicon to form an intermetallic compound of Mg2Si, which induces alloy strengthening by precipitation. The magnesium may be contained in an amount of 0.70-0.85% by weight, preferably 0.70-0.80% by weight, more preferably 0.75-0.80% by weight. When the magnesium content is less than 0.70% by weight, the possibility of sticking at the time of processing chip is increased, and the material property may be lowered due to the relative decrease of MgSi precipitation phase, which is a mechanism for strengthening the physical properties due to the formation of tin and precipitate phase. When the magnesium content is more than 0.85% by weight, the fibrous texture in the alloy base is strengthened, and the machining property improvement effect may be insufficient because the machined chip length becomes long.

In the AlMgSi-based aluminum alloy, tin reacts with the magnesium element to form a magnesium-tin (Mg-Sn) precipitate phase, and this precipitation phase plays a role of chip breaking during processing, and the workability can be improved. Therefore, the above characteristics may be excessive or deficient depending on the content of tin. As a result of observing the shapes and lengths of chips generated during processing according to the content of tin, the content of tin may be 0.8-1.2 wt%, preferably 0.8-1.0 wt%, more preferably 0.8-0.85 wt% have. If the tin content is less than 0.8% by weight, the effect of improving the workability of the aluminum alloy may be insufficient. If the tin content is more than 1.20% by weight, the size of the processed chips may be small, but the possibility of damage to the tools during processing may increase due to the interfaced chips.

In the AlMgSi-based aluminum alloy, manganese can improve the extrudability and the extruded surface by changing the acicular β-AlFeSi into spherical α-AlFeSi. For this purpose, manganese may be contained in an amount of 0.01-0.40 wt%, preferably 0.01-0.35 wt%, more preferably 0.30-0.35 wt%. When the content of manganese is less than 0.01% by weight, an acicular shape of a compound such as AlFeSi can be produced, and the grain refining effect can be small. When the content of manganese exceeds 0.40% by weight, the strength of the aluminum alloy may be lowered.

Iron (Fe), copper (Cu), chromium (Cr) and zinc (Zn) in the AlMgSi-based aluminum alloy must be added as unavoidable impurities to the extent that they do not impair the determined alloy properties. The higher the content of iron, copper, chromium and zinc, the more the alloy properties may be impaired. Specifically, iron may be contained in an amount of 0.50% by weight or less, preferably 0.001-0.5% by weight, and copper in an amount of 0.10% by weight or less, preferably 0.01-0.1% by weight. The chromium may be contained in an amount of 0.25% by weight or less, preferably 0.01-0.25% by weight, and the zinc may be contained in an amount of 0.20% by weight or less, preferably 0.01-0.20% by weight.

The content of titanium (Ti) in the AlMgSi-based aluminum alloy may be 0% by weight. The AlMgSi-based aluminum alloy of the present invention can secure sufficient workability without containing titanium.

In the AlMgSi-based aluminum alloy, the unavoidable impurities are each contained in an amount of 0.05 wt% or less, preferably 0.01-0.05 wt%, and the total amount of impurities is 0.15 wt% or less, preferably 0.05-0.15 wt%. Within this range, generation of intermetallic compounds between dissimilar metals can be suppressed without impairing the physical properties of the aluminum alloy.

The AlMgSi-based aluminum alloy including the elements having the weight fraction of the present invention has excellent mechanical workability and strength, thereby reducing the machining cycle type and reducing the remaining amount of the bur according to the improvement of workability.

A method of manufacturing an AlMgSi-based aluminum alloy according to another aspect of the present invention may include the following steps:

(Si), 1.0-1.4 wt% of silicon, 0.70-0.85 wt% of magnesium, 0.8-1.20 wt% of tin, 0.01-0.4 wt% of manganese (Mn), 0.001-0.50 wt% of iron (Fe) A composition for an AlMgSi-based aluminum alloy comprising 0.01-0.10 wt% of copper (Cu), 0.01-0.25 wt% of chromium (Cr), 0.01-0.20 wt% of zinc (Zn), and aluminum (Al) Producing a billet through a performance process; And

Subjecting the prepared billet to homogenization heat treatment, extrusion, stretching and aging heat treatment.

The steps of preparing the composition for an AlMgSi-based aluminum alloy through the casting process and the homogenizing heat treatment, extrusion and stretching of the prepared billet may be carried out by a method known to a person skilled in the art.

The aging heat treatment may vary the heat treatment temperature depending on the required properties. Specifically, the precipitation behavior of the compound due to the addition of tin differs, so that the heat treatment is preferably performed at 130-180 ° C, more preferably at 130-150 ° C, It may be preferable in terms of prevention of precipitation.

An automotive part, which is another aspect of the present invention, can be made of the AlMgSi-based aluminum alloy. Examples of the automotive parts are not limited, and may be ABS, ESC pump housing, or the like.

Hereinafter, the structure and operation of the present invention will be described in more detail with reference to preferred embodiments of the present invention. It is to be understood, however, that the same is by way of illustration and example only and is not to be construed in a limiting sense.

The contents not described here are sufficiently technically inferior to those skilled in the art, and a description thereof will be omitted.

Example  1 and Comparative Example  1-3

In order to evaluate the characteristics of the aluminum alloy, an aluminum alloy composition having the composition (unit: parts by weight) according to the following Table 1 was prepared. The specimens were prepared by homogenizing heat treatment, extrusion, stretching and aging heat treatment at 150 ℃.

Si Mg Sn Mn Fe Cu Cr Zn Al and
impurities Example 1 1.25 0.75 0.85 0.35 0.20 0.03 0.15 0.02 Balance Comparative Example 1 1.0 0.55 1.0 0.005 0.20 0.03 0.15 0.02 Balance Comparative Example 2 1.2 0.95 1.0 0.55 0.20 0.03 0.15 0.02 Balance Comparative Example 3 1.2 0.55 1.0 0.55 0.20 0.03 0.15 0.02 Balance

The prepared specimens were evaluated for workability and hardness, and the results are shown in Table 2 below.

Processability burglar Example 1 Great
(No chip curling, no tool breakage.
Burr residual amount Great
(HB 104-110) Comparative Example 1 usually Inadequate
(HB 88-90) Comparative Example 2 Mm.
(Chip curled) usually
(HBs 102-105) Comparative Example 3 Classroom
(Small diameter drill breakage) usually
(HB 98-100)

As shown in Table 2, the aluminum alloy according to the present invention had excellent workability because of no chip curling and residual burr, and the strength of the specimen was excellent.

On the other hand, the aluminum alloy of Comparative Example 1 in which the content of manganese is less than 0.01% by weight has a high likelihood of forming an irregular shape of a compound such as AlFeSi and a slight grain refinement effect, resulting in a decrease in the hardness value.

In addition, the aluminum alloy of Comparative Example 2 having a magnesium content of more than 0.85 wt% strengthened the fibrous structure in the alloy matrix, resulting in an increase in the length of the processed chips, resulting in poor processability improvement and chip curling.

In addition, the aluminum alloy of Comparative Example 3 having a magnesium content of less than 0.07% by weight had breakage of a small diameter drill due to high sintering at the time of forming a machining chip, and a decrease in the MgSi precipitation phase due to the formation of tin and precipitates, Can be lowered.

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.

Claims (7)

1. A method for producing an AlMgSi-based aluminum alloy, the method comprising the steps of: (a) providing an aluminum alloy containing 1.0-1.4 wt% of silicon, 0.70-0.85 wt% of magnesium, 0.8-1.20 wt% of tin, 0.01-0.4 wt% ), 0.001-0.50 wt% copper, 0.01-0.10 wt% copper, 0.01-0.25 wt% chromium (Cr), 0.01-0.20 wt% zinc (Zn), and the balance of unavoidable impurities and aluminum AlMgSi-based aluminum alloy.
The AlMgSi-based aluminum alloy according to claim 1, wherein the content of manganese (Mn) is 0.01-0.35 wt%.
The AlMgSi-based aluminum alloy according to claim 1, wherein the inevitable impurities are 0.01-0.05 wt% and 0.05-0.15 wt%, respectively.
The AlMgSi-based aluminum alloy according to claim 1, wherein the content of titanium (Ti) in the AlMgSi-based aluminum alloy is 0% by weight.
(Si), 1.0-1.4 wt% of silicon, 0.70-0.85 wt% of magnesium, 0.8-1.20 wt% of tin, 0.01-0.4 wt% of manganese (Mn), 0.001-0.50 wt% of iron (Fe) A composition for an AlMgSi-based aluminum alloy comprising 0.01-0.10 wt% of copper (Cu), 0.01-0.25 wt% of chromium (Cr), 0.01-0.20 wt% of zinc (Zn), and aluminum (Al) Producing a billet through a performance process; And
And subjecting the prepared billet to homogenization heat treatment, extrusion, stretching and aging heat treatment.
6. The method according to claim 5, wherein the content of manganese (Mn) is 0.01-0.35 wt%.
An automotive part made of the AlMgSi-based aluminum alloy according to any one of claims 1 to 4.