U.S. patent application number 12/690812 was filed with the patent office on 2010-09-09 for al-si-mg alloy and method of producing the same.
This patent application is currently assigned to HYUNDAI MOBIS CO., LTD.. Invention is credited to GYEWON JANG, DAEUP KIM, WOOSIK LEE, KAEHEE OH, SANGWOO PARK.
Application Number | 20100224291 12/690812 |
Document ID | / |
Family ID | 42538737 |
Filed Date | 2010-09-09 |
United States Patent
Application |
20100224291 |
Kind Code |
A1 |
JANG; GYEWON ; et
al. |
September 9, 2010 |
Al-Si-Mg ALLOY AND METHOD OF PRODUCING THE SAME
Abstract
An Al--Si--Mg-based aluminum alloy includes about 1.2 to about
1.4 wt % of Si, about 0.6 to about 0.75 wt % of Mg, about 0.8 to
about 1.0 wt % of Sn, and Al and impurities as the balance on the
basis of the total weight of the aluminum alloy.
Inventors: |
JANG; GYEWON; (YONGIN-SI,
KR) ; KIM; DAEUP; (YONGIN-SI, KR) ; LEE;
WOOSIK; (YONGIN-SI, KR) ; PARK; SANGWOO;
(SEOUL, KR) ; OH; KAEHEE; (SEOUL, KR) |
Correspondence
Address: |
KNOBBE MARTENS OLSON & BEAR LLP
2040 MAIN STREET, FOURTEENTH FLOOR
IRVINE
CA
92614
US
|
Assignee: |
HYUNDAI MOBIS CO., LTD.
SEOUL
KR
DONGYANG GANGCHUL CO., LTD.
DAEJEON
KR
|
Family ID: |
42538737 |
Appl. No.: |
12/690812 |
Filed: |
January 20, 2010 |
Current U.S.
Class: |
148/551 ;
420/530 |
Current CPC
Class: |
C22F 1/05 20130101; C22C
21/02 20130101; C22C 21/04 20130101; C22F 1/043 20130101 |
Class at
Publication: |
148/551 ;
420/530 |
International
Class: |
C22F 1/05 20060101
C22F001/05; C22C 21/12 20060101 C22C021/12; C22C 21/04 20060101
C22C021/04 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 3, 2009 |
KR |
10-2009-0018109 |
Claims
1. An Al--Si--Mg-based alloy comprising: Si in an amount of about
1.2 to about 1.4 wt %; Mg in an amount of about 0.6 to about 0.75
wt %; Sn in an amount of about 0.8 to about 1.0 wt %; and Al,
wherein each amount is with reference to the total weight of the
alloy.
2. The alloy as defined in claim 1, further comprising Mn in an
amount of about 0.50 to about 0.70 wt % with reference to the total
weight of the alloy.
3. The alloy as defined in claim 1, further comprising one or more
selected from the group consisting of: Fe in an amount of about
0.001 to about 0.50 wt %; Cu in an amount of about 0.01 to about
0.10 wt %; Cr in an amount of about 0.01 to about 0.25 wt %; and Zn
in an amount of about 0.01 to about 0.20 wt %, wherein each amount
is with reference to the total weight of the alloy.
4. A method for producing an Al--Si--Mg-based alloy, the method
comprising: providing a composition for an Al--Si--Mg-based alloy,
the composition comprising: Si in an amount of about 1.2 to about
1.4 wt %; Mg in an amount of about 0.6 to about 0.75 wt %; Sn in an
amount of about 0.8 to about 1.0 wt %; and Al, wherein each amount
is with reference to the total weight of the composition; forming
the composition into one or more billets through a continuous
casting process; and subjecting the one or more billets to
stretching, and aging heat treatment, wherein the aging heat
treatment is carried out at a temperature between about 130 and
150.degree. C.
5. The method as defined in claim 4, wherein the composition
further comprising Mn in an amount of about 0.50 to about 0.70 wt %
with reference to the total weight of the composition.
6. The method as defined in claim 5, wherein the composition
further includes one or more selected from the group consisting of:
Fe in an amount of about 0.001 to about 0.50 wt %; Cu in an amount
of about 0.01 to about 0.10 wt %; Cr in an amount of about 0.01 to
about 0.25 wt %; and Zn in an amount of about 0.01 to about 0.20 wt
%, wherein each amount is with reference to the total weight of the
composition.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is based on, and claims priority
from, Korean Application Serial Number 10-2009-0018109, filed on
Mar. 3, 2009, the disclosure of which is hereby incorporated by
reference herein in its entirety.
BACKGROUND
[0002] 1. Field
[0003] The present disclosure relates to an Al--Si--Mg-based
aluminum alloy that has excellent machinability and a method for
producing the same.
[0004] 2. Discussion of the Related Technology
[0005] A general 6000 series (Al--Mg--Si-based) wrought aluminum
alloy is commercially used as part materials such as ABS (Anti-lock
Breaking system) pump housings for vehicles, ESC (Electronic
Stability Control) pump housings and the like.
[0006] However, in the case of the general 6000 series
(Al--Mg--Si-based) wrought aluminum alloy, since the machinability
is not good, length of processed chips become long. The long chips
curl processing tools and increase a load applied to the tools
while processing is carried out. Accordingly, there are
disadvantages in that poor processing and damage to processing
tools are caused, a processing speed is lowered, and the quality of
processed products is lowered.
[0007] Therefore, in the case of when a general 6000 series wrought
aluminum alloy are used as part materials such as ABS (Anti-lock
Breaking system) pump housings or ESC (Electronic Stability
Control) pump housings, there are problems in that a production
cost is increased and the quality of parts is lowered.
SUMMARY
[0008] Embodiments of the present invention help overcome the
drawbacks in the related art and it is an aspect of the invention
to provide wrought aluminum alloy, which has high machinability and
does not cause problems such as chip curling while processing is
carried out or a damage to processing tools by changing the
composition of the 6000 series wrought aluminum alloy that is
generally used in the related art to improve the machinability, and
a method for producing the same.
[0009] One aspect of the present invention provides an
Al--Si--Mg-based aluminum alloy which comprises about 1.2 to about
1.4 wt % of Si, about 0.6 to about 0.75 wt % of Mg, about 0.8 to
about 1.0 wt % of Sn, and Al and impurities as the balance on the
basis of the total weight of the aluminum alloy.
[0010] Further, a method for producing an Al--Si--Mg-based aluminum
alloy according to one embodiment of the present invention
comprises the steps of preparing a composition for an
Al--Si--Mg-based aluminum alloy that includes about 1.2 to about
1.4 wt % of Si, about 0.6 to about 0.75 wt % of Mg, about 0.8 to
about 1.0 wt % of Sn, and Al and impurities as the balance on the
basis of the total weight of the aluminum alloy; producing the
composition for an aluminum alloy into billets through a continuous
casting process; and performing uniform heat treatment, extrusion,
stretching, and aging heat treatment in respects to the produced
billets in the above step, wherein the aging heat treatment is
carried out at about 130 to about 150.degree. C.
[0011] Since the wrought aluminum alloy according to one embodiment
of the present invention has very excellent machinability and does
not cause problems such as chip curling while processing is carried
out or a damage to processing tools, a processing cycle time is
shortened. In addition, the defect ratio of processed products is
largely lowered, the quality of processed products is improved, and
the residual amount of burr is lowered, such that it is easy to
remove and wash burrs. Therefore, the wrought aluminum alloy
according to one embodiment of the present invention largely
contributes to an improvement of productivity while processing is
carried out and provides a large cost reduction effect.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] For better understanding of the nature and features of the
present invention, reference should be made to the following
detailed description with the accompanying drawings, in which:
[0013] FIG. 1 illustrates pictures of shapes of chips that are
generated while specimens of the aluminum alloys that are produced
in Example 1 and Comparative Examples 1 to 3 are processed [(a)
Comparative Example 1, (b) Comparative Example 2, (c) Comparative
Example 3, and (d) Example 1].
DETAILED DESCRIPTION OF EMBODIMENTS
[0014] The present disclosure relates to an Al--Si--Mg-based
aluminum alloy that comprises 1.2 to 1.4 wt % of Si, 0.6 to 0.75 wt
% of Mg, 0.8 to 1.0 wt % of Sn, and Al and impurities as the
balance on the basis of the total weight of the aluminum alloy.
[0015] The aluminum alloy according to one embodiment of the
present invention is characterized in that Sn that is a low melting
point metal is added in order to improve processing characteristics
of the 6000 series wrought aluminum alloy material and the contents
of Si and Mg are optimized in order to prevent reduction of
physical properties of the material according to the addition of Sn
and to improve the physical properties thereof.
[0016] In the present disclosure, "impurities" means undesired
components that are included in the course of producing the
alloy.
[0017] Among the components that are included in the aluminum alloy
according to one embodiment of the present invention, it is
preferable that Si is included in a content in the range of 1.2 to
1.4 wt %. If it is included in a content of less than 1.2 wt %,
there is a problem in that hardness of the alloy is lowered. If it
is included in a content of more than 1.4 wt %, since a reduction
in casting speed occurs according to the high alloy content while
wrought billet is produced, the productivity is reduced, an
extrusion speed is lowered according to an increase in fluidity
stress of a material in extrusion, and the quality of the surface
thereof is lowered. In addition, because of an increase in hardness
value according to the effect of excessive Excess-Si, there is a
problem in that an amount of tool abrasion is increased.
[0018] Among the components that are included in the aluminum alloy
according to one embodiment of the present invention, it is
preferable that Mg is included in a content in the range of 0.6 to
0.75 wt %. If it is included in a content of less than 0.6 wt %, a
possibility of burning while processed chips are generated is
increased, the content of the Mg.sub.2Si precipitate phase that
functions to reinforce physical properties is relatively lowered
because of the generation of Mg--Sn-based precipitate phases, such
that physical properties of the material are lowered. If it is
included in a content of more than 0.75 wt %, since a fibrous
structure in a base is reinforced, the length of the processed chip
becomes long, and thus the machinability is lowered.
[0019] Among the components that are included in the aluminum alloy
according to one embodiment of the present invention, Sn generates
Mg--Sn-based precipitate phases with the Mg, and the precipitate
phases function to break chips while processing is carried out,
thus improving the machinability. Therefore, in accordance with the
content of Sn, these characteristics are excessive or poor. If Sn
is included in a content of less than 0.8 wt %, the improvement
effect of the machinability is insignificant. If Sn is included in
a content of more than 1.0 wt %, the size of processed chip is
small, but a possibility of generation of damage to tools is
increased while processing is carried out because of burning
between the processed chips.
[0020] It is preferable that the aluminum alloy according to one
embodiment of the present invention further includes 0.50 to 0.70
wt % of Mn on the basis of the total weight of the aluminum alloy.
Mn is an element that suppresses the generation of the precipitate
shape of the compound such as AlFeSi and is effective to make
crystal grains fine in order to improve strength. If Mn is included
in a content of less than 0.50 wt %, there is a high possibility of
generation of the precipitate shape of the compound such as AlFeSi
and the fine crystal grain effect is insignificant. If Mn is
included in a content of more than 0.70 wt %, there is a problem in
that strength is lowered.
[0021] In addition, the aluminum alloy of one embodiment of the
present invention may further include one or more that are selected
from the group consisting of 0.001 to 0.50 wt % of Fe, 0.01 to 0.10
wt % of Cu, 0.01 to 0.25 wt % of Cr, and 0.01 to 0.20 wt % of Zn on
the basis of the total weight of the aluminum alloy. If the content
of the component exceeds the above range, a reduction in physical
properties may occur in accordance with the generation of the
compound between metals, and the extrudability is lowered, such
that the productivity is lowered.
[0022] In addition, other components other than the above-mentioned
components can be included in a content of 0.15 wt % or less. It is
preferable that the aluminum alloy of one embodiment of the present
invention have the content of fine elements controlled as described
above in order to suppress the generation of the compound between
different metals.
[0023] In addition, the present disclosure relates to a method for
producing an Al--Si--Mg-based aluminum alloy, which comprises the
steps of preparing a composition for an Al--Si--Mg-based aluminum
alloy that includes 1.2 to 1.4 wt % of Si, 0.6 to 0.75 wt % of Mg,
0.8 to 1.0 wt % of Sn, and Al and impurities as the balance on the
basis of the total weight of the aluminum alloy; producing the
composition for an aluminum alloy into billets through a continuous
casting process; and performing uniform heat treatment, extrusion,
stretching, and aging heat treatment in respects to the produced
billets in the above step, wherein the aging heat treatment is
carried out at 130 to 180.degree. C.
[0024] Among the above production methods, the remaining process
except for the composition for the Al--Si--Mg-based aluminum alloy
and the temperature of the aging heat treatment may be carried out
by using the method that is known in the art. The aging heat
treatment may change the temperature of the heat treatment in
accordance with the required physical properties. Because of the
characteristics of the above composition, for example, a change in
precipitation dynamics of the compound by the addition of Sn,
unlike a known method, it is preferable that the temperature of the
aging heat treatment is in the range of 130 to 150.degree. C. More
preferably, the heat treatment process is carried out at
140.degree. C. in order to form the uniform precipitate phase
distribution and to prevent the coarse precipitation.
[0025] In the production method, it is more preferable that the
composition for the aluminum alloy further include 0.50 to 0.70 wt
% of Mn on the basis of the total weight of the aluminum alloy. In
addition, the aluminum alloy according to one embodiment of the
present invention may further include one or more that are selected
from the group consisting of 0.001 to 0.50 wt % of Fe, 0.01 to 0.10
wt % of Cu, 0.01 to 0.25 wt % of Cr, and 0.01 to 0.20 wt % of Zn on
the basis of the total weight of the aluminum alloy.
[0026] Hereinbelow, embodiments of the present invention will be
described in detail with reference to Examples. However, the
present invention should not be construed as being limited to the
Examples set forth herein. Rather, the following Examples may be
changed appropriately by those skilled in the art within the
concept of the invention.
Example 1 to Comparatives 1 to 3
Production of the Aluminum Alloy
[0027] In order to confirm the characteristics (tensile strength,
yield strength, and elongation ratio) of the aluminum alloy
according to one embodiment of the present invention, the aluminum
alloy samples of Example 1 and Comparative Examples 1 to 3 were
produced by using the component compositions of the following Table
1.
TABLE-US-00001 TABLE 1 Si Mg Sn Mn Fe Cu Cr Zn Al and impurities
Example 1 1.25 0.68 0.85 0.55 0.20 0.03 0.15 0.02 residual amount
Comparative 1.0 0.55 1.0 0.55 0.20 0.03 0.15 0.02 residual Example
1 amount Comparative 1.2 0.95 1.0 0.55 0.20 0.03 0.15 0.02 residual
Example 2 amount Comparative 1.2 0.55 1.0 0.55 0.20 0.03 0.10 0.02
residual Example 3 amount (unit: wt %)
Experimental Example 1
Evaluation of the Machinability and the Hardness of the Aluminum
Alloy
[0028] The machinability and the hardness of the aluminum alloy
samples that were produced in Example 1 and Comparative Examples 1
to 3 were evaluated, and the results were described in the
following Table 2.
TABLE-US-00002 TABLE 2 Si Mg Sn machinability hardness Example 1
1.25 0.65 0.85 excellent excellent (no chip curling, (HB 104 to
110) no damage to tools, and small residual amount of burr
Comparative 1.0 0.55 1.0 Normal poor Example 1 (HB 88 to 90)
Comparative 1.2 0.95 1.0 poor normal Example 2 (chip curling (HB
102 to 105) occurs) Comparative 1.2 0.55 1.0 Poor normal Example 3
(a damage to (HB 98 to 100) drill having a small diameter)
Experimental Example 2
Evaluation of the Tensile Strength, Yield Strength and Elongation
of the Aluminum Alloy
[0029] The tensile strength, yield strength and elongation ratio of
the samples of Example 1 and the commercial aluminum alloy were
evaluated, and the results were described in the following Table
3.
TABLE-US-00003 TABLE 3 Tensile Yield elongation Notice (MPa) (MPa)
ratio (%) Example 1 371 337 14.7 6082 357 336 13.6 commercial
alloy
[0030] From data described in Table 3, it can be seen that the
aluminum alloy according to one embodiment of the present invention
is more excellent than the 6082 commercial alloy in views of the
tensile strength, yield strength and elongation ratio.
Experimental Example 3
Evaluation of the Processing Speed of the Aluminum Alloy
[0031] The machinability of the samples of Example 1 and the 6082
commercial alloy were evaluated by using four kinds of drills
having the small diameter, and the results were described in the
following Table 4.
TABLE-US-00004 TABLE 4 Commercial notice products Example 1 remark
.PHI. 3.275 spindle speed (rpm) 15,000 15,000 100% Feeding speed
2,000 4,000 improvement .PHI. 3.63 spindle speed (rpm) 15,000
15,000 10% Feeding speed 3,000 3,500 improvement .PHI. 4.64 spindle
speed (rpm) 12,000 13,500 Feeding speed 1,500 1,800 .PHI. 5.25
spindle speed (rpm) 10,000 11,000 Feeding speed 1,300 1,500
* * * * *