U.S. patent application number 16/917110 was filed with the patent office on 2021-08-05 for aluminum alloy composition and manufacturing method thereof.
The applicant listed for this patent is Delta Electronics, Inc.. Invention is credited to En-Yi Chu, Yu-Xian Huang, Fei-Yi Hung.
Application Number | 20210238715 16/917110 |
Document ID | / |
Family ID | 1000004939275 |
Filed Date | 2021-08-05 |
United States Patent
Application |
20210238715 |
Kind Code |
A1 |
Hung; Fei-Yi ; et
al. |
August 5, 2021 |
ALUMINUM ALLOY COMPOSITION AND MANUFACTURING METHOD THEREOF
Abstract
The present disclosure provides an aluminum alloy composition
and a manufacturing method thereof. By utilizing the mutually
insoluble properties between tantalum and silver and sequentially
adding chromium, tantalum and silver to an aluminum master alloy
containing copper in plural times of melting, it avoids the
eutectic reaction between chromium and silver, and required
eutectic compositions are formed. Thus, the aluminum alloy
composition with excellent corrosion resistance, fatigue
resistance, wear resistance and high-temperature resistance is
obtained. The aluminum alloy composition comprises 4.2 to 5.5
weight percent copper, 1.4 to 2.0 weight percent magnesium, 0.5 to
1.2 weight percent manganese, 0.05 to 1.0 weight percent silicon,
0.05 to 0.8 weight percent chromium, 0.01 to 0.5 weight percent
tantalum, 0.01 to 0.5 weight percent silver and the balance of
aluminum.
Inventors: |
Hung; Fei-Yi; (Taoyuan City,
TW) ; Huang; Yu-Xian; (Taoyuan City, TW) ;
Chu; En-Yi; (Taoyuan City, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Delta Electronics, Inc. |
Taoyuan City |
|
TW |
|
|
Family ID: |
1000004939275 |
Appl. No.: |
16/917110 |
Filed: |
June 30, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C22C 1/026 20130101;
C22C 21/18 20130101; C22C 21/14 20130101; C22C 21/16 20130101 |
International
Class: |
C22C 21/18 20060101
C22C021/18; C22C 21/16 20060101 C22C021/16; C22C 21/14 20060101
C22C021/14; C22C 1/02 20060101 C22C001/02 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 3, 2020 |
CN |
202010078483.2 |
Claims
1. An aluminum alloy composition comprising: 4.2 to 5.5 weight
percent copper, 1.4 to 2.0 weight percent magnesium, 0.5 to 1.2
weight percent manganese, 0.05 to 1.0 weight percent silicon, 0.05
to 0.8 weight percent chromium, 0.01 to 0.5 weight percent
tantalum, 0.01 to 0.5 weight percent silver and the balance of
aluminum.
2. The aluminum alloy composition according to claim 1, further
comprising 0.05 to 0.8 weight percent zinc.
3. The aluminum alloy composition according to claim 2, further
comprising 0.05 to 1.0 weight percent iron and 0.01 to 0.3 weight
percent titanium.
4. The aluminum alloy composition according to claim 1, wherein the
aluminum alloy composition comprises an aluminum-chromium eutectic
composition, wherein the aluminum-chromium eutectic composition
comprises an atomic ratio aluminum/chromium of 1:2.
5. The aluminum alloy composition according to claim 1, wherein the
aluminum alloy composition comprises an aluminum-tantalum eutectic
composition, wherein the aluminum-tantalum eutectic composition
comprises an atomic ratio aluminum/tantalum of 3:1.
6. The aluminum alloy composition according to claim 1, wherein the
aluminum alloy composition comprises an aluminum-copper-tantalum
eutectic composition, wherein the aluminum-copper-tantalum eutectic
composition comprises an atomic ratio aluminum/copper/tantalum of
3:1:1 or an atomic ration aluminum/tantalum/copper of 2:1:1.
7. The aluminum alloy composition according to claim 1, wherein the
aluminum alloy composition comprises an aluminum-silver eutectic
composition, wherein the aluminum-silver eutectic composition
comprises an atomic ratio aluminum/silver of 1:2.
8. The aluminum alloy composition according to claim 1, wherein the
aluminum alloy composition comprises an aluminum-chromium-silver
eutectic composition, wherein the aluminum-chromium-silver eutectic
composition comprises an atomic ratio silver/chromium/aluminum of
2:1:1.
9. A manufacturing method of an aluminum alloy composition,
comprising the following steps in the sequence set forth: (S1)
providing an aluminum master alloy, wherein the aluminum master
alloy comprises aluminum and copper; (S2) adding chromium to the
aluminum master alloy and performing a first melting; (S3) adding a
tantalum-chromium alloy and performing a second melting; and (S4)
adding silver and performing a third melting to form the aluminum
alloy composition.
10. The manufacturing method according to claim 9, wherein the
tantalum-chromium alloy in the step (S3) comprises an atomic ratio
chromium/tantalum of 2:1.
11. The manufacturing method according to claim 9, wherein the
aluminum master alloy in the step (S1) comprises aluminum, copper,
magnesium, manganese and silicon, and the aluminum alloy
composition in the step (S4) comprises 4.2 to 5.5 weight percent
copper, 1.4 to 2.0 weight percent magnesium, 0.5 to 1.2 weight
percent manganese, 0.05 to 1.0 weight percent silicon, 0.05 to 0.8
weight percent chromium, 0.01 to 0.5 weight percent tantalum, 0.01
to 0.5 weight percent silver and the balance of aluminum.
12. The manufacturing method according to claim 11, wherein the
aluminum master alloy in the step (S1) further comprises zinc, and
the aluminum alloy composition in the step (S4) further comprises
0.05 to 0.8 weight percent zinc.
13. The manufacturing method according to claim 12, wherein the
aluminum master alloy in the step (S1) further comprises iron and
titanium, and the aluminum alloy composition in the step (S4)
further comprises 0.05 to 1.0 weight percent iron and 0.01 to 0.3
weight percent titanium.
14. The manufacturing method according to claim 9, wherein an
aluminum-chromium eutectic composition is formed after the chromium
is added to the aluminum master alloy and the first melting is
performed in the step (S2), wherein the aluminum-chromium eutectic
composition comprises an atomic ratio aluminum/chromium of 1:2.
15. The manufacturing method according to claim 9, wherein an
aluminum-tantalum eutectic composition is formed after the
tantalum-chromium alloy is added and the second melting is
performed in the step (S3), wherein the aluminum-tantalum eutectic
composition comprises an atomic ratio aluminum/tantalum of 3:1.
16. The manufacturing method according to claim 9, wherein an
aluminum-copper-tantalum eutectic composition is formed after the
tantalum-chromium alloy is added and the second melting is
performed in the step (S3), wherein the aluminum-copper-tantalum
eutectic composition comprises an atomic ratio
aluminum/copper/tantalum of 3:1:1 or an atomic ration
aluminum/tantalum/copper of 2:1:1.
17. The manufacturing method according to claim 9, wherein an
aluminum-silver eutectic composition is formed after the silver is
added and the third melting is performed in the step (S4), wherein
the aluminum-silver eutectic composition comprises an atomic ratio
aluminum/silver of 1:2.
18. The manufacturing method according to claim 9, wherein an
aluminum-chromium-silver eutectic composition is formed after the
silver is added and the third melting is performed in the step
(S4), wherein the aluminum-chromium-silver eutectic composition
comprises an atomic ratio silver/chromium/aluminum of 2:1:1.
Description
FIELD OF THE INVENTION
[0001] The present disclosure relates to an aluminum alloy
composition, and more particularly to an aluminum alloy composition
with excellent corrosion resistance, fatigue resistance, wear
resistance and high-temperature resistance, and a manufacturing
method thereof.
BACKGROUND OF THE INVENTION
[0002] The density of aluminum alloy material is about one third of
that of copper or steel. The corrosion resistance, the
processability, the thermal conductivity and the electrical
conductivity of the aluminum alloy material are excellent.
Moreover, the surface treatment characteristics of the aluminum
alloy material are good. Therefore, the aluminum alloy material has
been widely used in the fields of aerospace, automobiles, bridges,
construction, machinery manufacturing, electrical furniture,
semiconductors and so on.
[0003] In response to the requirements of different application
fields, the mechanical properties of the aluminum alloy material
are improved by adding other ingredients to an aluminum master
alloy. Taking the application of a speed reducer or a force sensor
as an example, the aluminum alloy material must meet the basic
requirements of corrosion resistance, fatigue resistance, wear
resistance, high-temperature resistance, and high mechanical
strength. It is a common way to improve the mechanical strength of
aluminum alloy by adding a copper alloy or a copper-magnesium alloy
to the aluminum master alloy. Thereby, an aluminum-copper-magnesium
alloy with high mechanical strength is formed. However, while the
mechanical strength of the aluminum-copper-magnesium alloys is
improved, the problems of such as poor corrosion resistance, poor
fatigue resistance, poor wear resistance and poor high-temperature
resistance are caused. It fails to meet the basic requirements of
speed reducer or force sensor.
[0004] Therefore, there is a need of providing an aluminum alloy
composition with corrosion resistance, fatigue resistance, wear
resistance and high-temperature resistance, and a manufacturing
method thereof, so as to address the above issues encountered by
the prior arts.
SUMMARY OF THE INVENTION
[0005] An object of the present disclosure is to provide an
aluminum alloy composition and a manufacturing method thereof. By
adding chromium in an aluminum master alloy with copper contained
therein, an aluminum-chromium eutectic composition (AlCr.sub.2) is
formed, and it is helpful of solving the problems of poor corrosion
resistance and poor fatigue resistance. By adding tantalum in the
aluminum master alloy, an aluminum-tantalum eutectic composition
(Al.sub.3Ta) is formed or an aluminum-copper-tantalum eutectic
composition (Al.sub.3(Cu)Ta or Al.sub.2(Ta)Cu) is further formed
due to a sufficient amount of copper contained in the aluminum
master alloy, and it is helpful of solving the problem of poor wear
resistance. By adding silver, an aluminum-silver eutectic
composition (Ag.sub.2Al) is formed, or an aluminum-chromium-silver
eutectic composition (Ag.sub.2(Cr)Al) is further formed due to an
additional amount of chromium in the aluminum master alloy, and it
is helpful of solving the problem of poor high-temperature
resistance.
[0006] Another object of the present disclosure is to provide an
aluminum alloy composition and a manufacturing method thereof. With
the mutually insoluble properties between tantalum and silver,
chromium, tantalum and silver are added in the aluminum master
alloy with copper contained therein sequentially, and the first
melting, the second melting, and the third melting are performed,
sequentially. Moreover, the eutectic reaction generated when
chromium and silver are added simultaneously is avoided. Thus the
eutectic compositions required are formed, and the aluminum alloy
composition with excellent corrosion resistance, fatigue
resistance, wear resistance and high-temperature resistance is
obtained. When the aluminum alloy composition is applied to for
example but not limited to the speed reducer or the force sensor,
the properties of corrosion resistance, fatigue resistance, wear
resistance and high-temperature resistance meets the basic
requirements, and it also prevents from increasing the excessive
cost of the raw material for the aluminum alloy composition.
[0007] In accordance with an aspect of the present disclosure, an
aluminum alloy composition is provided. The aluminum alloy
composition comprises 4.2 to 5.5 weight percent copper, 1.4 to 2.0
weight percent magnesium, 0.5 to 1.2 weight percent manganese, 0.05
to 1.0 weight percent silicon, 0.05 to 0.8 weight percent chromium,
0.01 to 0.5 weight percent tantalum, 0.01 to 0.5 weight percent
silver and the balance of aluminum.
[0008] In accordance with another aspect of the present disclosure,
a manufacturing method of an aluminum alloy composition is
provided. The manufacturing method comprises the following steps in
the sequence set forth: (S1) providing an aluminum master alloy,
wherein the aluminum master alloy comprises aluminum and copper;
(S2) adding chromium to the aluminum master alloy and performing a
first melting; (S3) adding a tantalum-chromium alloy and performing
a second melting; and (S4) adding silver and performing a third
melting to form the aluminum alloy composition.
[0009] The above contents of the present disclosure will become
more readily apparent to those ordinarily skilled in the art after
reviewing the following detailed description and accompanying
drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a flow chart illustrating a manufacturing method
of an aluminum alloy composition according to an embodiment of the
present disclosure.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0011] The present disclosure will now be described more
specifically with reference to the following embodiments. It is to
be noted that the following descriptions of preferred embodiments
of this disclosure are presented herein for purpose of illustration
and description only. It is not intended to be exhaustive or to be
limited to the precise form disclosed.
[0012] FIG. 1 is a flow chart illustrating a manufacturing method
of an aluminum alloy composition according to an embodiment of the
present disclosure. In the embodiment, the aluminum alloy
composition is applied to for example but not limited to a speed
reducer or a force sensor. Since the working environment of the
speed reducer or the force sensor is harsh, the aluminum alloy
composition used must have high mechanical strength, and meets the
requirements of corrosion resistance, fatigue resistance, wear
resistance and high-temperature resistance. In the embodiment, as
shown in the step S1, an aluminum master alloy is provided firstly.
The aluminum master alloy at least contains aluminum and copper.
Preferably but not exclusively, in an embodiment, the aluminum
master alloy is a 2024 aluminum alloy in accordance with the
standards of the Aluminum Association (AA) in the USA. In addition
to the aluminum, the 2024 aluminum alloy further contains copper,
magnesium, manganese, silicon and other elements. Thereafter, as
shown in the step S2, chromium is added to the aforementioned
aluminum master alloy for performing a first melting in a melting
furnace. Preferably but not exclusively, the vacuum degree of the
melting furnace for performing the first melting is less than
10.sup.-2 Pa, and the melting temperature of the melting furnace
for performing the first melting is ranged from 700.degree. C. to
800.degree. C., higher than the melting point of aluminum, which is
660.3.degree. C. During the first melting, the raw materials in the
melting furnace are stirred continuously for mixing well. In an
embodiment, when the chromium content is greater than, for example,
3.8 weight percent (wt. %) relative to the aluminum master alloy,
an aluminum-chromium eutectic composition (AlCr.sub.2) is formed in
the aluminum alloy composition. The aluminum-chromium eutectic
composition contains an atomic ratio aluminum/chromium of 1:2.
Notably, by adding the chromium in the aluminum master alloy with
the copper contained therein, an aluminum-chromium eutectic
composition (AlCr.sub.2) is formed, and it is helpful of solving
the problems of poor corrosion resistance and poor fatigue
resistance.
[0013] Thereafter, in the step S3, a tantalum-chromium alloy is
added into the aforementioned melting furnace for performing a
second melting. Preferably but not exclusively, the vacuum degree
of the melting furnace for performing the second melting is less
than 10.sup.-2 Pa, and the melting temperature of the melting
furnace for performing the second melting is ranged from
700.degree. C. to 800.degree. C. During the second melting, the raw
materials in the melting furnace are stirred continuously for
mixing well. Since the melting point of tantalum is as high as
3017.degree. C., if it is added directly for performing the second
melting, it will take a long time to melt. In the embodiment, by
adding the tantalum-chromium alloy, the second melting is completed
in a shorter melting time. Moreover, the tantalum-chromium alloy
provides an additional amount of chromium for the aluminum alloy
composition, and the chromium content in the Step S2 is further
increased. In the embodiment, by adding the tantalum in the
aluminum master alloy, an aluminum-tantalum eutectic composition
(Al.sub.3Ta) is formed. The aluminum-tantalum eutectic composition
contains an atomic ratio aluminum/tantalum of 3:1. In the
embodiment, when a sufficient amount of copper is contained in the
aluminum master alloy, an aluminum-copper-tantalum eutectic
composition (Al.sub.3(Cu)Ta or Al.sub.2(Ta)Cu) with wear resistance
is further formed. The aluminum-copper-tantalum eutectic
composition contains an atomic ratio aluminum/copper/tantalum of
3:1:1 or an atomic ration aluminum/tantalum/copper of 2:1:1. It is
helpful of solving the problem of poor wear resistance. In the
embodiment, the tantalum-chromium alloy contains an atomic ratio
chromium/tantalum of 2:1. Namely, the tantalum-chromium alloy
comprises 12 weight percent (wt. %) tantalum and 88 weight percent
(wt. %) chromium.
[0014] Then, in the step S4, silver is added into the
aforementioned melting furnace for performing a third melting.
Preferably but not exclusively, the vacuum degree of the melting
furnace for performing the third melting is less than 10.sup.-2 Pa,
and the melting temperature of the melting furnace for performing
the third melting is ranged from 700.degree. C. to 800.degree. C.
During the third melting, the raw materials in the melting furnace
are stirred continuously for mixing well. Thereby, the aluminum
alloy composition of the present disclosure is formed. By adding
the silver, an aluminum-silver eutectic composition (Ag.sub.2Al) is
formed. The aluminum-silver eutectic composition contains an atomic
ratio aluminum/silver of 1:2. Furthermore, an
aluminum-chromium-silver eutectic composition (Ag.sub.2(Cr)Al) is
formed by mixing the aluminum-silver eutectic composition and the
aforementioned additional amount of chromium. The
aluminum-chromium-silver eutectic composition contains an atomic
ratio silver/chromium/aluminum of 2:1:1. It is helpful of solving
the problem of poor high-temperature resistance. Notably, since the
melting point of silver is 961.8.degree. C. far less than the
melting point of tantalum 3017.degree. C. and the silver and the
tantalum are insoluble with each other, while the silver and the
chromium are added simultaneously, an eutectic reaction of the
silver and the chromium will occur, and the composition and the
performance of aluminum alloy composition are affected. Therefore,
with insoluble properties between the tantalum and the silver, the
chromium, the tantalum and the silver are added sequentially into
the aluminum master alloy with the copper contained therein for
performing the first melting, the second melting and the third
melting, sequentially. It avoids the eutectic reaction due to
simultaneous addition of the chromium and the silver. Moreover, the
required eutectic compositions are formed, so as to obtain the
aluminum alloy composition with excellent corrosion resistance,
fatigue resistance, wear resistance and high-temperature
resistance. In the embodiment, the aluminum alloy composition
comprises 4.2 to 5.5 weight percent copper, 1.4 to 2.0 weight
percent magnesium, 0.5 to 1.2 weight percent manganese, 0.05 to 1.0
weight percent silicon, 0.05 to 0.8 weight percent chromium, 0.01
to 0.5 weight percent tantalum, 0.01 to 0.5 weight percent silver
and the balance of aluminum. In some embodiments, the aluminum
master alloy contains aluminum, copper, magnesium, manganese and
silicon, and further contains zinc. Thereby, the aluminum alloy
composition comprises at least 4.2 to 5.5 weight percent copper,
1.4 to 2.0 weight percent magnesium, 0.5 to 1.2 weight percent
manganese, 0.05 to 1.0 weight percent silicon, 0.05 to 0.8 weight
percent chromium, 0.01 to 0.5 weight percent tantalum, 0.01 to 0.5
weight percent silver, 0.05 to 0.8 weight percent zinc and the
balance of aluminum. In the other embodiments, the aluminum master
alloy contains aluminum, copper, magnesium, manganese and silicon,
and further contains zinc, iron and titanium. Thereby, the aluminum
alloy composition comprises at least 4.2 to 5.5 weight percent
copper, 1.4 to 2.0 weight percent magnesium, 0.5 to 1.2 weight
percent manganese, 0.05 to 1.0 weight percent silicon, 0.05 to 0.8
weight percent chromium, 0.01 to 0.5 weight percent tantalum, 0.01
to 0.5 weight percent silver, 0.05 to 0.8 weight percent zinc, 0.05
to 1.0 weight percent iron, 0.01 to 0.3 weight percent titanium and
the balance of aluminum. The present disclosure is not limited
thereto.
[0015] In the embodiment, after the chromium, the tantalum and the
silver are added sequentially into the aluminum master alloy with
the copper contained therein for the three times of melting, the
aforementioned aluminum alloy composition is further produced by
refining, deslagging, homogenization treatment, solution treatment
and artificial full aging treatment (Heat treating temper code,
T6), so as to prepare a test sample of the aluminum alloy
composition, which are utilized for testing the features of fatigue
resistance, corrosion resistance, wear resistance, and
high-temperature resistance. Certainly, the present disclosure is
not limited thereto. For testing the fatigue resistance, the test
sample is subjected to a tensile testing at a frequency of 10 Hz
under a pressure of 150 Mpa. Thus, a fatigue life (N) is recorded.
The more the fatigue life (N) is, the higher the fatigue resistance
is. For testing corrosion resistance, the test sample is immersed
in a 3.5 weight percent (wt. %) sodium chloride (NaCl) solution and
a polarization curve is obtained by the polarization testing. Thus,
a corrosion potential (Ecorr V) is further calculated. The more the
corrosion potential decreases, the better the corrosion resistance.
For testing the wear resistance, solid powders of silicon oxide
(SiO.sub.2) or aluminum oxide (Al.sub.2O.sub.3) are used as erosion
particles of parameters, to erode the surface of the test sample at
an erosion angle of for example 30.degree.. Thus, an erosion rate
is recorded. The erosion rate refers to the percentage of the mass
loss of the test sample relative to the total mass of the solid
powders of erosion particles. The lower the percentage value is,
the better the wear resistance is. As to testing the
high-temperature resistance, it is produced by observing the change
in tensile strength at room temperature and high temperature.
[0016] Notably, by utilizing the insoluble properties between the
tantalum and the silver, the chromium, the tantalum and the silver
are added sequentially into the aluminum master alloy with the
copper contained therein for performing the first melting, the
second melting and the third melting, sequentially, so as to obtain
the aluminum alloy composition of the present disclosure. It avoids
the eutectic reaction due to simultaneous addition of the chromium
and the silver, so as to prevent from affecting the composition and
the performance of the aluminum alloy composition. Moreover, the
required eutectic compositions are formed, so as to obtain the
aluminum alloy composition with excellent corrosion resistance,
fatigue resistance, wear resistance and high-temperature
resistance. In addition, the aluminum alloy composition is applied
to for example but not limited to the speed reducer or the force
sensor and meets the requirements thereof. It avoids increasing the
excessive cost of the raw material for the aluminum alloy
composition. In the embodiment, the aluminum alloy composition
comprises 4.2 to 5.5 weight percent copper, 1.4 to 2.0 weight
percent magnesium, 0.5 to 1.2 weight percent manganese, 0.05 to 1.0
weight percent silicon, 0.05 to 0.8 weight percent chromium, 0.01
to 0.5 weight percent tantalum, 0.01 to 0.5 weight percent silver
and the balance of aluminum. In some embodiments, the aluminum
master alloy contains aluminum, copper, magnesium, manganese and
silicon, and further contains zinc. Thereby, the aluminum alloy
composition comprises 4.2 to 5.5 weight percent copper, 1.4 to 2.0
weight percent magnesium, 0.5 to 1.2 weight percent manganese, 0.05
to 1.0 weight percent silicon, 0.05 to 0.8 weight percent chromium,
0.01 to 0.5 weight percent tantalum, 0.01 to 0.5 weight percent
silver, 0.05 to 0.8 weight percent zinc and the balance of
aluminum. The subsequent exemplary samples are described by
combining the procedures of the first melting, the second melting
and the third melting to illustrate the effects, which are achieved
by sequentially adding the chromium, the tantalum, and the silver
to the aluminum master alloy with the copper contained therein.
[0017] In a comparative example 1, the 2024 aluminum alloy in
accordance with the standards of Aluminum Association (AA) is used
as the aluminum master alloy and placed in the melting furnace for
performing the first melting. The vacuum degree of the melting
furnace for performing the first melting is less than 10.sup.-2 Pa,
the melting temperature of the melting furnace for performing the
first melting is maintained at 700.degree. C., and the raw
materials in the melting furnace are stirred continuously for
mixing well during the first melting. After the first melting, the
composition of the aluminum master alloy is further produced by
solution treatment and artificial full aging treatment, so as to
obtain a test sample of the comparative example 1. In the
comparative example 1, the composition of the aluminum master alloy
at least contains 4.9 weight percent copper, 1.8 weight percent
magnesium, 0.9 weight percent manganese, 0.5 weight percent
silicon, 0.5 weight percent iron, 0.25 weight percent zinc, 0.15
percent titanium and the balance of aluminum. The test sample of
the comparative example 1 is subjected to the tensile testing at
the frequency of 10 Hz under the pressure of 150 Mpa. The Fatigue
life (N) of the test sample of the comparative example 1 is listed
in Table 1. In addition, the test sample of the comparative example
1 is immersed in a 3.5 weight percent (wt. %) sodium chloride
(NaCl) for the corrosion potential testing. The obtained corrosion
potential (Ecorr V) of the test sample of the comparative example 1
is listed in Table 1.
[0018] While in examples 2 to 8, the 2024 aluminum alloy in
accordance with the standards of Aluminum Association (AA) and
similar to the comparative example 1 is used as the aluminum master
alloy. The aluminum master alloy and the chromium added in
different weights are placed in the melting furnace for performing
the first melting, respectively. The vacuum degree of the melting
furnace for performing the first melting is less than 10.sup.-2 Pa,
the melting temperature of the melting furnace for performing the
first melting is maintained at 700.degree. C., and the raw
materials in the melting furnace are stirred continuously for
mixing well during the first melting. After the first melting, the
aluminum alloy compositions are further produced by solution
treatment and artificial full aging treatment, respectively, so as
to obtain the test samples of the examples 2 to 8. In the test
samples of the examples 2 to 8, the chromium contents (wt. %)
contained in the aluminum alloy compositions are listed in Table 1.
The copper, the magnesium, the manganese, the silicon, the iron,
the zinc and the titanium contained in the aluminum alloy
compositions are maintained at the same content ratio relative to
the aluminum master alloy. The test samples of the examples 2 to 8
are subjected to the tensile testing and the corrosion potential
testing in the same conditions described above. The obtained
results of the fatigue life (N) and corrosion potential (Ecorr V)
are listed in Table 1.
TABLE-US-00001 TABLE 1 Fatigue Cr life Ecorr First melting (wt. %)
(N) .times. 10.sup.5 V Example 1 Aluminum master alloy 0 0.42
-0.730 Example 2 Aluminum master alloy + Cr 0.05 0.47 -0.741
Example 3 Aluminum master alloy + Cr 0.22 0.51 -0.752 Example 4
Aluminum master alloy + Cr 0.25 0.56 -0.779 Example 5 Aluminum
master alloy + Cr 0.67 0.60 -0.805 Example 6 Aluminum master alloy
+ Cr 0.80 0.60 -0.808 Example 7 Aluminum master alloy + Cr 0.97
0.60 -0.811 Example 8 Aluminum master alloy + Cr 1.22 0.60
-0.811
[0019] Among the results of the tensile testing and the corrosion
potential testing in Table 1, the composition of the aluminum
master alloy without the chromium in the comparative example 1 is
compared to the aluminum alloy compositions of the examples 2 to 8
of the present disclosure, which are obtained by adding the
chromium in different weight to the 2024 aluminum alloy in
accordance with the standards of Aluminum Association (AA) and
performing the first melting. Accordingly, as the chromium content
(wt. %) in the obtained aluminum alloy composition is increased,
the fatigue life (N) is increased, the corrosion potential is
decreased and the corrosion resistance is enhanced. Among them,
when the chromium content in the aluminum alloy composition is in
the range of 0.05 to 0.8 weight percent, the fatigue resistance and
the corrosion resistance are better. In other words, when the
chromium content of the aluminum alloy composition is ranged from
0.05 to 0.8 weight percent, the aluminum-chromium eutectic
composition (AlCr.sub.2) is formed in the aluminum alloy
composition, and it is helpful of solving the problems of poor
corrosion resistance and poor fatigue resistance.
[0020] While in examples 9 to 15, the 2024 aluminum alloy in
accordance with the standards of Aluminum Association (AA) and
similar to the comparative example 1 is used as the aluminum master
alloy. The chromium is added in the aluminum master alloy, and the
aluminum master alloy and the chromium added are placed in the
melting furnace for performing the first melting. Then, the
tantalum or the tantalum-chromium alloy is further added in
different weights for performing the second melting, respectively.
The vacuum degree of the melting furnace for performing the second
melting is less than 10.sup.-2 Pa, the melting temperature of the
melting furnace for performing the second melting is maintained at
700.degree. C., and the raw materials in the melting furnace are
stirred continuously for mixing well during the second melting.
After the first melting and the second melting are completed
sequentially, the aluminum alloy compositions are further produced
by solution treatment and artificial full aging treatment,
respectively, so as to obtain the test samples of the examples 9 to
15. In the test samples of the examples 9 to 15, the chromium added
in the first melting and the tantalum-chromium added in the second
melting are maintained at a constant chromium content (wt. %)
contained in the aluminum alloy compositions. The chromium contents
(wt. %) and the tantalum contents (wt. %) contained in the aluminum
alloy compositions of the example 9 to 15 are listed in Table 2.
The copper, the magnesium, the manganese, the silicon, the iron,
the zinc and the titanium contained in the aluminum alloy
compositions are maintained at the same content ratio relative to
the aluminum master alloy, and the aluminum alloy compositions
comprise the balance of the aluminum The test samples of the
examples 9 to 15 are subjected to the wear resistance testing, the
solid powder of silicon oxide (SiO.sub.2) are used as the erosion
particles for erosion medium, and the surfaces of the test samples
are eroded at an erosion angle of 30.degree., respectively. The
removal grams of the test samples eroded by the unit grams of the
erosion particles of silicon oxide (SiO.sub.2) are recorded, so as
to obtain the erosion rate 1 (g/g.times.10.sup.-4), respectively.
In addition, the test samples of the examples 9 to 15 are subjected
to the wear resistance testing, the solid powder of aluminum oxide
(Al.sub.2O.sub.3) are used as the erosion particles for erosion
medium, and the surfaces of the test samples are eroded at an
erosion angle of 30.degree., respectively. The removal grams of the
test samples eroded by the unit grams of the erosion particles of
aluminum oxide (Al.sub.2O.sub.3) are recorded, so as to obtain the
erosion rate 2 (g/g.times.10.sup.-4), respectively. The obtained
results of the erosion rate 1 (g/g.times.10.sup.-4) and the erosion
rate 2 (g/g.times.10.sup.-4) from the wear resistance testing of
the test samples of the examples 9 to 15 are listed in Table 2.
TABLE-US-00002 TABLE 2 Cr Ta Erosion rate 1 Erosion rate 2 Second
melting (wt. %) (wt. %) (g/g .times. 10.sup.-4) (g/g .times.
10.sup.-4) Example 9 Aluminum master alloy + Cr + Ta--Cr alloy 0.22
0.01 56 78 Example 10 Aluminum master alloy + Cr + Ta--Cr alloy
0.22 0.23 44 70 Example 11 Aluminum master alloy + Cr + Ta--Cr
alloy 0.22 0.25 32 62 Example 12 Aluminum master alloy + Cr +
Ta--Cr alloy 0.22 0.42 25 59 Example 13 Aluminum master alloy + Cr
+ Ta--Cr alloy 0.22 0.51 18 56 Example 14 Aluminum master alloy +
Cr + Ta--Cr alloy 0.22 0.78 17 56 Example 15 Aluminum master alloy
+ Cr + Ta--Cr alloy 0.22 0.81 16 55
[0021] Among the results of the wear resistance testing in Table 2,
the aluminum alloy compositions of the examples 9 to 15 of the
present disclosure are obtained by sequentially adding the chromium
and the tantalum to the aluminum master alloy and performing the
first melting and the second melting respectively. Accordingly, as
the tantalum content (wt. %) in the obtained aluminum alloy
composition is increased, both of the erosion rate 1
(g/g.times.10.sup.-4) and the erosion rate 2 (g/g.times.10.sup.-4)
are decreased, and the wear resistance is enhanced. Among them,
when the tantalum content in the aluminum alloy composition is in
the range of 0.01 to 0.5 weight percent, the wear resistance meets
the requirements of the application, such as in the speed reducer
or the force sensor. In other words, when the tantalum content of
the aluminum alloy composition is ranged from 0.01 to 0.5, an
aluminum-copper-tantalum eutectic composition (Al.sub.3(Cu)Ta or
Al.sub.2(Ta)Cu) with wear resistance is further formed due to the
sufficient amount of copper contained in the aluminum alloy
composition, and it is helpful of solving the problem of poor wear
resistance. Moreover, it also avoids increasing the excessive cost
of the raw material for the aluminum alloy composition as well. On
the other hand, the additions of the tantalum in the examples 9 to
15 are produced through the tantalum-chromium alloy. It is helpful
of shortening the melting time in the second melting. Moreover, the
chromium content of the tantalum-chromium alloy is added to
increase the chromium content in the previous first melting.
[0022] While in examples 16 to 25, the 2024 aluminum alloy in
accordance with the standards of Aluminum Association (AA) and
similar to the example 11 is used as the aluminum master alloy. The
chromium is added in the aluminum master alloy, and the aluminum
master alloy and the chromium added are placed in the melting
furnace for performing the first melting. The tantalum-chromium
alloy is further added for performing the second melting, and then
the silver is added in different weight for performing the third
melting, sequentially. The vacuum degree of the melting furnace for
performing the third melting is less than 10.sup.-2 Pa, the melting
temperature of the melting furnace for performing the third melting
is maintained at 700.degree. C., and the raw materials in the
melting furnace are stirred continuously for mixing well during the
third melting. After the first melting, the second melting and the
third melting are completed sequentially, the aluminum alloy
composition is further produced by solution treatment and
artificial full aging treatment, sequentially, so as to obtain the
test samples of the examples 16 to 25. In the test samples of the
examples 16 to 25 obtained after the first melting, the second
melting and the third melting, the chromium content (wt. %) and the
tantalum content (wt. %) contained in the aluminum alloy
composition are maintained at constant values, which are similar to
those of the example 11. The chromium contents (wt. %), the
tantalum contents (wt. %) and the silver contents (wt. %) contained
in the aluminum alloy compositions of the examples 16 to 25 are
listed in Table 3. The copper, the magnesium, the manganese, the
silicon, the iron, the zinc and the titanium contained in the
aluminum alloy compositions are maintained at the same content
ratio relative to the aluminum master alloy, and the aluminum alloy
compositions comprise the balance of the aluminum. The test samples
of the examples 16 to 25 are subjected to the tensile strength
testing at room temperature of 25.degree. C. and high temperature
of 200.degree. C. and 250.degree. C. The obtained results are
listed in Table 3.
TABLE-US-00003 TABLE 3 Tensile Tensile Tensile strength at strength
at strength Cr Ta Ag 25.degree. C. 200.degree. C. at 250.degree. C.
Third melting (wt. %) (wt. %) (wt. %) (Mpa) (Mpa) (Mpa) Example 16
Aluminum master alloy + 0.22 0.25 0.01 462 308 260 Cr + Ta--Cr
alloy + Ag Example 17 Aluminum master alloy + 0.22 0.25 0.22 469
312 264 Cr + Ta--Cr alloy + Ag Example 18 Aluminum master alloy +
0.22 0.25 0.24 475 316 268 Cr + Ta--Cr alloy + Ag Example 19
Aluminum master alloy + 0.22 0.25 0.31 481 324 273 Cr + Ta--Cr
alloy + Ag Example 20 Aluminum master alloy + 0.22 0.25 0.37 486
332 277 Cr + Ta--Cr alloy + Ag Example 21 Aluminum master alloy +
0.22 0.25 0.48 492 336 281 Cr + Ta--Cr alloy + Ag Example 22
Aluminum master alloy + 0.22 0.25 0.50 497 338 284 Cr + Ta--Cr
alloy + Ag Example 23 Aluminum master alloy + 0.22 0.25 0.53 498
339 285 Cr + Ta--Cr alloy + Ag Example 24 Aluminum master alloy +
0.22 0.25 0.70 505 340 286 Cr + Ta--Cr alloy + Ag Example 25
Aluminum master alloy + 0.22 0.25 0.86 511 340 287 Cr + Ta--Cr
alloy + Ag
[0023] Among the results of the tensile strength testing at room
temperature of 25.degree. C. and high temperature of 200.degree. C.
and 250.degree. C. in Table 3, the aluminum alloy compositions of
the examples 16 to 25 of the present disclosure are obtained by
adding the chromium, the tantalum and the silver to the aluminum
master alloy and performing the first melting, the second melting
and the third melting, sequentially. Accordingly, as the silver
content (wt. %) in the obtained aluminum alloy composition is
increased, the tensile strength at high temperature of 200.degree.
C. and the tensile strength at high temperature of 250.degree. C.
are enhanced, and the high-temperature resistance is improved.
Among them, when the silver content in the aluminum alloy
composition is in the range of 0.01 to 0.5 weight percent, the
high-temperature resistance meets the requirements of the
application, such as in the speed reducer or the force sensor. In
other words, when the silver content of the aluminum alloy
composition is ranged from 0.01 to 0.5, an aluminum-chromium-silver
eutectic composition (Ag.sub.2(Cr)Al) is formed by the additional
amount of chromium except for forming the aforementioned
aluminum-chromium eutectic composition (AlCr.sub.2). It is helpful
for solving the problem of poor high-temperature resistance.
Moreover, it also avoids increasing the excessive cost of the raw
material for the aluminum alloy composition as well. On the other
hand, due to the silver and the tantalum are insoluble with each
other and the eutectic reaction occurs while the silver and the
chromium are added simultaneous, the composition and the
performance of the aluminum alloy composition are affected easily.
Therefore, by utilizing the insoluble properties between the
tantalum and the silver, the chromium, the tantalum and the silver
are added sequentially into the aluminum master alloy with the
copper contained therein for performing the first melting, the
second melting and the third melting, respectively, so as to obtain
the aluminum alloy composition of the present disclosure. It avoids
the eutectic reaction due to simultaneous addition of the chromium
and the silver. Thus, the required eutectic compositions are
formed, and the aluminum alloy composition with excellent corrosion
resistance, fatigue resistance, wear resistance and
high-temperature resistance is obtained. When the aluminum alloy
composition of the present disclosure is applied to for example but
not limited to the speed reducer or the force sensor, it prevents
from increasing the excessive cost of the raw material for the
aluminum alloy composition.
[0024] In summary, the present disclosure provides an aluminum
alloy composition and a manufacturing method thereof. By adding
chromium in an aluminum master alloy with copper contained therein,
an aluminum-chromium eutectic composition (AlCr.sub.2) is formed,
and it is helpful of solving the problems of poor corrosion
resistance and poor fatigue resistance. By adding tantalum in the
aluminum master alloy, an aluminum-tantalum eutectic composition
(Al.sub.3Ta) is formed or an aluminum-copper-tantalum eutectic
composition (Al.sub.3(Cu)Ta or Al.sub.2(Ta)Cu) is further formed
due to a sufficient amount of copper contained in the aluminum
master alloy, and it is helpful of solving the problem of poor wear
resistance. By adding silver, an aluminum-silver eutectic
composition (Ag.sub.2Al) is formed, or an aluminum-chromium-silver
eutectic composition (Ag.sub.2(Cr)Al) is further formed due to an
additional amount of chromium in the aluminum master alloy, and it
is helpful of solving the problem of poor high-temperature
resistance. Furthermore, with the mutually insoluble properties
between tantalum and silver, the chromium, the tantalum, and the
silver are added in the aluminum master alloy with the copper
contained therein sequentially, and the first melting, the second
melting and the third melting are performed, respectively. The
eutectic reaction generated when chromium and silver are added
simultaneously is avoided. Thereby, the eutectic compositions
required are formed, and the aluminum alloy composition with
excellent corrosion resistance, fatigue resistance, wear resistance
and high-temperature resistance is obtained. When the aluminum
alloy composition is applied to for example but not limited to the
speed reducer or the force sensor, the properties of corrosion
resistance, fatigue resistance, wear resistance and
high-temperature resistance meets the basic requirements, and it
also prevents from increasing the excessive cost of the raw
material for the aluminum alloy composition.
[0025] While the disclosure has been described in terms of what is
presently considered to be the most practical and preferred
embodiments, it is to be understood that the disclosure needs not
be limited to the disclosed embodiment. On the contrary, it is
intended to cover various modifications and similar arrangements
included within the spirit and scope of the appended claims which
are to be accorded with the broadest interpretation so as to
encompass all such modifications and similar structures.
* * * * *