Note: Descriptions are shown in the official language in which they were submitted.
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LOW LEAD COPPER ALLOY
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to copper alloys, and more particularly, to
a low lead brass alloy.
2. Description of Related Art
Brass comprises copper and zinc, as major ingredients, usually at a ratio
of about 7:3 or 6:4. In addition, brass usually comprises a small amount of
impurities. In the context of improving the properties of brass, a
conventional brass contains lead (mostly in the range of I to 3 wt%) to
achieve the desired mechanical properties for use in industry, thereby
becoming an important industrial material that is widely applicable in
metallic devices and valves for use in pipelines, faucets and water supply
and discharge system.
However, as the awareness of environmental protection grows and the
impact of heavy metals on human health and issues like environmental
pollution become major focuses, there is a tendency to restrict the usage
of lead-containing alloys. Various countries, such as Japan and the United
States, etc, have sequentially amended relevant regulations in an effect to
lower lead content in the environment by particularly demanding that no
lead shall leach from lead-containing alloy materials used in products
ranging from electronic appliances and automobiles to faucets and water
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systems, and stipulating that lead contamination shall be avoided during
processing.
On another relevant matter, if the zinc content of brass exceeds 20 wt%,
corrosion (such as dezincification) is likely to occur. This occurs
particularly when brass is in an environment with a high concentration of
chlorine ions (such as a marine environment) in which dezincification
corrosion of brass is accelerated. Because dezincification seriously
damages the structure of brass, the surface intensity of brass products is
lowered and even pores may be formed in brass pipes. This significantly
decreases the lifespan of brass products, thereby causing application
problems.
Regarding the above issues of high lead contents and dezincification,
the industry continues to develop copper alloy formulations. For example,
in addition to copper and zinc as main ingredients, TW421674, US7354489,
US20070062615, US20060078458, US2004023441, US2002069942, etc.,
disclose lead-free copper alloy formulations containing silicon (Si) and
other elements. However, the drawback of these alloys is poor
machinability. CN10144045 discloses a lead-free copper alloy formulation
comprising aluminum, silicon and phosphorus as major ingredients.
Although this formulation can be used in casting, the alloy has poor
machinability and a processing efficiency much lower than that of a lead
brass. Thus, the alloy is not suitable for large-scale production.
CN101285138 and CN101285137 disclose lead-free copper alloy
formulations comprising phosphorus as a major element, but the
formulations are likely to lead to defects like cracks and slag inclusions in
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the alloy when they are used in casting. For example, US7297215,
US6974509, US6955378, US6149739, US5942056, US5653827,
US5487867, US5330712, US 5637160, US20060005901, US20040094243,
US20070039667, etc. disclose brass alloys comprising added bismuth (Bi).
The bismuth content of the above alloy formulations approximately range
from 0.5 wt% to 7 wt%. However, the high bismuth content is likely to lead
to defects like cracks and slag inclusions. Further, the high bismuth content
leads to higher production costs, making it adverse to commercialization.
US6413330 discloses a lead-free copper alloy formulation comprising
ingredients like bismuth, silicon, etc. CN101440444 discloses a lead-free
high zinc brass alloy. Because the zinc brass alloy has a combination of
high silicon content and low copper content, the alloy has poor fluidity in
the molten state. The poor fluidity makes the molten alloy fill in the cavity
of a metallic mold more slowly, thereby causing defects like misrun.
CN101403056 discloses a brass alloy comprising bismuth and manganese,
but the high bismuth content is likely to cause defects like cracks and slag
inclusions. The combination of low bismuth content and high manganese
content causes a high degree of hardness, such that chip breaking is less
likely to occur and machinability is poor. Moreover, the brass alloy
formulation still has defects like poor casting properties and material
embrittlement.
Furthermore, regarding the formulations of dezincification-resistant
brass alloys, in addition to copper and zinc as principle ingredients, US
4417929 discloses a formulation comprising iron, aluminum and silicon,
US 5507885 and US 6395110 disclose formulations comprising phosphorus,
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tin and nickel, US 5653827 discloses a formulation comprising iron, nickel
and bismuth, US 6974509 discloses a formulation comprising tin, bismuth,
iron, nickel and phosphorus, US 6787101 discloses a formulation
comprising phosphorus, tin, nickel, iron, aluminum, silicon and arsenic, all
at the same time, and US 6599378 and US 5637160 disclose adding
selenium and phosphorus in brass alloys to achieve a dezincifying effect.
Conventional dezincification-resistant brasses usually have higher lead
contents (most in the range from 1 to 3 wt%), which facilitates
cold/thermal processing of brass materials. However, they do not meet
environmental requirements, because lead leaching is high and lead
contamination is likely to occur during processing.
Thus, the industry continues to develop brass materials, and to seek for
an alloy formulation that can substitute for lead-containing brasses while
possessing desirable properties like good dezincification corrosion
resistance, casting properties, machinability, corrosion resistance and
mechanical properties. S
SUMMARY OF THE INVENTION
In order to attain the above and other objectives, the present invention
provides a dezincification-resistant copper alloy, comprising 0.05 to 0.3
wt% of lead; 0.3 to 0.8 wt% of aluminum; 0.01 to 0.1 wt% of bismuth; 1 to
4 wt% of silicon; 0.1 to I wt% of tin; and more than 93.8% of copper and
zinc, wherein the copper is more than 74.8 wt%, and the zinc is in an
amount ranging from 15.6 to 19 wt%.
In an embodiment, the low-lead copper ally of the present invention is
comprised of copper and zinc in a total amount ranging from 93.8 to 98.54
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wt%, and preferably more than 94 wt%. In an embodiment, copper is
present in the low-lead copper alloy in an amount ranging from 61 to 78
wt%, preferably ranging from 62 to 74 wt%, and more preferably ranging
from 66 to 72 wt%. As mentioned, the low-lead copper alloy of the present
invention also comprises a silicon ingredient. Therefore, as compared with
conventional lead brasses, the low-lead copper alloy of the present
invention must have higher copper content, so as to provide the alloy
material with good toughness.
In the low-lead copper alloy of the present invention, the lead content
ranges from 0.05 to 0.3 wt%. In a preferred embodiment, the lead content
ranges from 0.1 to 0.25 wt%, and more preferably ranges from 0.15 to 0.20
wt%. Addition of an appropriate amount of lead can increase the
machinability of the brass alloy.
In the low-lead copper alloy of the present invention, the bismuth
content is less than 0.3 wt%. In an embodiment, the bismuth content ranges
from 0.01 to 0.3 wt%, preferably ranges from 0.05 to 0.25 wt%, and more
preferably ranges from 0.1 to 0.2 wt%. Addition of an appropriate amount
of bismuth is beneficial to increasing machinability of the alloy.
In the low-lead copper alloy of the present invention, the aluminum
content ranges from 0.3 to 0.8 wt%. In a preferred embodiment, the
aluminum content ranges from 0.4 to 0.7 wt%, and preferably ranges from
0.5 to 0.65 wt%. Addition of an appropriate amount of aluminum can
increase the fluidity of a copper liquid, and improve the casting properties
of the alloy material.
In the low-lead copper alloy of the present invention, the silicon content
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ranges from 1 to 4 wt%. In a preferred embodiment, the silicon content
ranges from 1.5 to 3.5 wt%, and more preferably ranges from 2 to 3 wt%.
Addition of an appropriate amount of silicon can increase the machinability
of the brass, and increase the corrosion resistance and stress corrosion
resistance of the alloy material in an environment with a high concentration
of chlorine ions (such as a marine environment).
In the lower-lead copper alloy of the present invention, the tin content
ranges from 0.1 to I wt%. In a preferred embodiment, the tin content
ranges from 0.2 to 0.9 wt%, and preferably ranges from 0.4 to 0.8 wt%.
Addition of an appropriate amount of tin can increases the corrosion
resistance of the alloy material in an environment with a high concentration
of chlorine ions (such as a marine environment), and increases the intensity
of the alloy material.
Moreover, addition of silicon and bismuth in the copper alloy maintains
the machinability of the alloy material when it has low lead content, and
increases the corrosion resistance of the alloy material in an environment
with a high concentration of chlorine ions (such as a marine environment).
The low-lead copper alloy of the present invention can be a substitute
material for conventional lead-containing brasses, and has excellent casting
properties and good machinability and mechanical properties. Further, the
low-lead copper alloy of the present invention comprises an extremely low
lead content, thereby complying with environmental regulations. At the
same time, the low-lead copper alloy of the present invention has good
dezincification corrosion resistance, especially resistance to high
concentrations of chlorine ions. Thus, the alloy of the present invention is
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suitable for application to environments with higher concentrations of
chlorine ions, such as marine waters and swimming pools.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram showing the relationship of the kinetic property and
the zinc content of a copper alloy;
FIG. 2A is a metallographic structural distribution of a specimen of an
C85710 lead brass;
FIG. 2B is a metallographic structural distribution of a specimen of a
low-lead brass of the present invention;
FIG. 3A is a metallographic structural distribution of a specimen of the
C85710 lead brass after a test of dezincification corrosion resistance was
performed;
FIG. 3B is a metallographic structural distribution of a specimen of the
low-lead brass of the present invention after a test of dezincification
corrosion resistance was performed; and
FIG. 4 is a schematic diagram of an inlaid sample in an electrochemical
test.
DETAILED DESCRIPTION OF THE PREFERRED
EMBODIMENTS
The detailed description of the present invention is illustrated by the
following specific examples. Persons skilled in the art can conceive of
other advantages and effects of the present invention based on the
disclosure contained in the specification of the present invention.
Unless otherwise specified, the ingredients comprised in the copper
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alloy of the present invention, as discussed herein, are all based on the
total weight of the alloy, and are expressed in weight percentages (wt%).
FIG. 1 is a graph showing the relationship of the kinetic property and
the zinc content of a copper material. As for (a+O) dual phases, before the
zinc content of the alloy reaches 45%, the intensity of the alloy increases
with increasing zinc content at room temperature. Once the zinc content
exceeds 45%, due to the appearance of y phase in the metallographic
distribution of the alloy, the embrittlement of the structure is increased,
and the intensity of the alloy is drastically decreased. On the other hand,
regarding a brass alloy formulation comprising complex ingredients, "zinc
equivalents" of the elements comprised in the formulation are used to
calculate the zinc content. Because the copper alloy of the present
invention comprises silicon, the zinc equivalent of silicon is 10. That is,
when 1% silicon is added in a Cu-Zn alloy, the metallographic structure of
the alloy is comparable to the metallographic structure of a Cu-Zn alloy
with 10% zinc content. As such, addition of silicon in the brass alloy
enables &(a+13) phase boundary in the Cu-Zn alloy to obviously shift to the
copper side, strongly reducing in the a phase region. Therefore, the silicon
content of the alloy should be no higher than 4 wt%. Silicon content of
higher than 4 wt% is likely to lead to the presence of y phase, which
increases the embrittlement of the structure. Further, the copper alloy of
the present invention should comprise higher copper content, so that good
intensity and toughness of the alloy material are maintained. In the
low-lead copper alloy of the present invention, the zinc equivalents of the
comprised ingredients are as follows: zinc equivalent of 10 for silicon, zinc
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equivalent of 6 for aluminum, zinc equivalent of 2 for tin, zinc equivalent
of 1 for lead, and zinc equivalent of 1 for bismuth.
The low-lead copper alloy formulation according to the present
invention can have lead content that is lowered to the range of 0.05 to 0.3
wt%, to comply with international standards of lead content of pipeline
materials in contact with water. Hence, the low-lead copper alloy according
to the present invention is beneficial to the manufacture of faucets and
lavatory components, pipelines for tap water, water supply systems, etc.
In an embodiment, the low-lead copper alloy of the present invention
comprises 61 to 78 wt% of copper, 0.05 to 0.3 wt% of lead, 0.3 to 0.8 wt%
of aluminum, 0.01 to 0.3 wt% of bismuth, I to 4 wt% of silicon, 0.1 to 1
wt% of tin, and zinc in balance.
In an embodiment, the the low-lead copper alloy of the present
invention comprises 62 to 74 wt% of copper, 0.1 to 0.25 wt% of lead, 0.4
to 0.7 wt% of aluminum, 0.05 to 0.25 wt% of bismuth, 1.5 to 3.5 wt% of
silicon, 0.2 to 0.9 wt% of tin, and zinc in balance, wherein unavoidable
impurities are less than 0.1 wt%.
In an embodiment, the the low-lead copper alloy of the present
invention comprises 66 to 72 wt% of copper, 0.15 to 0.25 wt% of lead, 0.5
to 0.65 wt% of aluminum, 0.2 to 0.3 wt% of bismuth, 2 to 3 wt% of silicon,
0.4 to 0.8 wt% of tin, and zinc in balance, wherein unavoidable impurities
are less than 0.1 wt%.
The present invention is illustrated by the following exemplary
examples.
The ingredients of the the low-lead copper alloy of the present
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invention used in the following test examples are described below,
wherein each of the ingredients is added at a proportion based on the total
weight of the alloy.
Example 10
Cu072.21. wtO A100.594 wtO
Bi00.178 wtO . Si02.732 wtO
Sn00.498 wtO Pb00.141 wt%
Zn: in balance
Example 20
Cu074.23 wtf A100.451 wtO
Bi00.169 wtO Si02.941 wt%
Sn00.645 wtO Pb00.184 wt%
ZnOin balance
Example 30
Cu069.91 wtO A100.554 wtO
Bi00.183 wtO Si02.941 wt%
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..............
Sn00.762 wtO Pb00.136 wt%
ZnOin balance
Example 40
Cu062.47 wtO A100.684 wt0
BiOO.187 wt0 Si02.123 wt%
Sn00.417 wtO PbfO.193 wt%
ZnOin balance
Test Example 1:
Rounded sand, a urea formaldehyde resin, a furan resin and a curing
agent were used as raw materials to prepare a sand core using a core
shooter, and the gas evolutions of the resins were measured using a testing
machine for testing gas evolutions. The obtained sand core must be
completely used within 5 hours, or it needs to be baked dry.
The low-lead brass alloy of the present invention and scrap returns
were preheated for 15 minutes to reach a temperature higher than 4000.
Then, the alloy of the present invention and the scrap returns were mixed at
a weight ratio of 7:1, along with addition of 0.2 wt% of refining slag, for
melting in an induction furnace at a temperature ranging from 1100 to
10500 until the brass alloy reached a certain molten state (hereinafter
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referred to as "molten copper liquid"). A metallic gravity casting machine
coupled with the sand core and the gravity casting molds to perform casting,
and a temperature monitoring system further controlled temperatures so as
to maintain the casting temperature in a range from 1060 to 10800. In each
casting, the feed amount was preferably 1 to 2 kilograms, and the casting
time was controlled to a range of 3 to 8 seconds. By the above
high-temperature melting and low-temperature rapid casting, segregation of
silicon in the alloy structure can be effectively avoided.
After the molds were cooled, the molds were opened and the casting
head was cleaned. The mold temperatures were monitored so as to control
the mold temperatures in a range from 200 to 2200 to form casting parts.
Then, the casting parts were released from the molds. Then, the molds were
cleaned to ensure that the site of the core head was clean. A graphite liquid
was spread on the surfaces of the molds following by cooling by immersion.
The temperature of the graphite liquid for cooling the mold was preferably
maintained in a range from 30 to 360, and the specific weight of the
graphite liquid ranged from 1.05 to 1.06.
Inspaction was performed on the cooled casting parts, and the casting
parts were sent into a sand cleaning drum for cleaning. Then, an as-cast
treatment was performed, wherein a thermal treatment for distressing
annealing was performed on as-casts to eliminate the internal stress
generated by casting. The as-casts were subsequently mechanically
processed and polished, so that no sand, metal powder or other impurities
adhered to the cavities of the casting parts. A quality inspection analysis
was performed and the overall production yield was calculated by the
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following equation.
O.P. Yield = Number of Non-Defective Products/Total Number of
Products x 100%
The overall production yield reflects the qualitative stability of
production processes. High qualitative stability of production processes
ensures normal production.
Moreover, a conventional C85710 lead brass was used as a comparative
example to produce products by the same process as described above. The
ingredients, processing characteristics and overall production yield of each
of the alloys are shown in Table 1.
Table 1
Ingredients, Processing Characteristics and Overall Production Yield of
the Alloys
C85710 Lead Brass Low-Lead Brass of the Present Invention
Category Comparative Comparative
Example 1 Example 2 Example 3 Example 4
Example 1 Example 2
Measured Cu
61.5 61.1 72.21 74.23 69.91 62.47
Content (%)
Measured Al
0.607 0.589 0.594 0.451 0.554 0.684
Content (%)
Measured Pb
1.47 1.54 0.141 0.184 0.136 0.193
Content (%)
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Measured Bi
0.0119 0.0089 0.178 0.169 0.183 0.187
Content (%)
Measured Si
0.0002 0.0002 2.732 2.941 2.421 2.123
Content (%)
Measured Sn
<0.0005 <0.0005 0.498 0.645 0.762 0.417
Content (%)
Casting Yield 96% 95% 94% 93% 92% 91%
Processing
99% 99% 97% 97% 98% 97%
Yield
Polishing Yield 92% 94% 96% 95% 95% 96%
Overall
Production 87.4% 88.4% 87.5% 85.7% 85.6% 84.7%
Yield
The material fluidity of the low-lead brass of the Further, the low-lead
brass of the present invention had low sensitivity to embrittlement, and
can maintain machinability of the material while not being particularly
susceptible to defects like cracks. Thus, the low-lead brass of the present
invention can satisfy the needs of production processes.
As shown in Table 1, as for the test group in which the low-lead brass
of the present invention was used as a raw material, the yield can be more
than 80%. Also, the material fluidity of the low-lead brass of the present
invention was close to that of the conventional C85710 lead brass, and the
yield of the low-lead brass of the present invention was also comparable
to that of the C85710 lead brass. Hence, the low-lead brass of the present
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invention can indeed be a substitute material for the C85710 lead brass.
The low-lead brass of the present invention also has the advantage of
having low-lead content, thereby meeting environmental needs and
statutes.
Test Example 2:
FIGs. 2A and 2B show the metallographic structural distributions of
the brass materials when the specimens were examined under an optical
metallographic microscope at I00X magnification.
FIG. 2A shows the metallographic structural distribution of the
C85710 lead brass (Comparative Example 2). The measured values of the
major ingredients of the C85710 lead brass are as follows: Cu: 61.1 wt%,
Al: 0.589 wt%, Pb: 1.54 wt%, Bi: 0.0089 wt%, and Si: 0.0002 wt%. The
alloy had an a phase, and the grains were granular.
The measured values of the ingredients of the low-lead brass of
Example 1 are as follows: Cu: 72.21 wt%, Al: 0.594 wt%, Pb: 0.141 wt%,
Bi: 0.178 wt%, Si: 2.732 wt% and Sn: 0.498 wt%. FIG. 2B shows the
metallographic structural distribution of the low-lead brass of Example I.
As shown in FIG. 2B, Example 1 exhibited an equitaxed dendritic crystal
phase structure having low sensitivity to embrittlement. Because grains
are dendritic and granular, chip breaking of the material can provide good
machinability.
Test Example 3:
A dezincification test was performed on the brass alloys of Example I
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and Comparative Example 1 to test the corrosion resistance of the brasses.
The dezincification test was performed according to the Australian
standard AS2345-2006 "Dezincification resistance of copper alloys."
Before a corrosion experiment was performed, a novolak resin was used
for inlaying to make the exposed area of each of the specimens to be 100
mm2. All the specimens were ground flat using a #600 metallographic
abrasive paper, following by washing using distilled water. Then, the
specimens were baked dry. The test solution was 1% CuC12 solution
prepared before use, and the test temperature was 75 2D. The specimens
and the CuC12 solution were placed in a temperature-controlled water bath
to react for 24 0.5 hours. The specimens were removed from the water
bath, and cut along the vertical direction. The cross-sections of the
specimens were polished, and then the depths of corrosion of the
specimens were measured and observed under a digital metallographic
electron microscope. Results are shown in FIGs. 3A and 3B.
As shown in FIG. 3A, the average depth of dezincification for
Comparative Example 1 was 372.54 14m. As shown in FIG. 3B, the average
depth of dezincification for Example 1 was 37.67 m. It can be
corroborated from the above that the low-lead brass of the present
invention had better dezincification corrosion resistance.
Test Example 4:
A test of the average levels of corrosion of the brass alloys of
Example 1 and Comparative Example 1 was performed by an
electrochemical method, so as to determine the average corrosion
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resistance of the brass alloys. The specimens of the brass alloys were
polished and inlaid into a sample 1 as shown in FIG. 4, wherein the length
of the surface of a brass specimen 11 exposed on the Inlaid Sample I was
about 10 mm, the depth of the brass specimen 11 chelated in a resin layer
12 was about 12 mm, and the brass was coupled to a conductive wire 13.
The Inlaid Sample I was immersed in a 5% sodium chloride solution.
A polarization curve of polarization potential versus electric current
density was plotted by employing a linear polarization method, and the
polarization resistance Rp was calculated using the following formula.
Specifically, the greater the Rp value is, the better the average corrosion
resistance of the material.
RP = AEOAI,
where RP representa the polarization resistance, AE represents polarization
potential, and AI represents external electric current density.
Table 2
Polarization Resistance Comparison
Inlay Sample No.
Comparative Example I Example 1
Category
#1 #2 #3 Avg. #1 #2 #3 Avg.
Polarization
Resistance RP 5.72 5.65 6.21 5.83 15.73 16.17 16.65 16.17
(KSZ/cm2)
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As shown in Table 2, the RP value (i.e., 16.17 KSl/cm2) of the low-lead
brass of the present invention was way higher than that (i.e., 5.83 KS2/cm2)
of the C85710 lead brass. It is corroborated that the low-lead brass alloy
of the present invention had excellent average corrosion resistance,
particularly in an environment with a high concentration of chlorine ions.
Thus, the low-lead brass alloy of the present invention can be a material
for products in an environment with a high concentration of chlorine ions.
Examples include, but are not limited to, pipelines for use in swimming
pools or pipelines for use in marine environments.
Test Example 5:
A test of mechanical properties was performed on the brass alloys
according to the standard set forth in IS06998-1998 "Tensile experiments
on metallic materials at room temperature." Results are shown in Table 3.
Table 3
Precipitation Amounts of the Metals in the Products
Mechanical Properties
Material
Tensile StrengthOMpaO ElongationUOO
Type
1 2 3 4 5 Avg. 1 2 3 4 5 Avg.
Example 1 398 404 421 417 391 406.2 12 12 11 10 13 11.6
Comparative
356 337 363 374 367 359.6 12 11 13 13 12 12.2
Example 1
As shown in Table 3, the tensile strength of the low-lead brass alloy of
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the present invention was higher than that of the conventional C85710
lead brass, and the elongation of the low-lead brass alloy of the present
invention was comparable to that of the C85710 lead brass, indicating that
the low-lead brass alloy of the present invention had mechanical
properties comparable to those of the C857 10 lead brass. Nevertheless, the
low-lead brass of the present invention has low-lead content, thereby
meeting environmental demands. Thus, the low-lead brass of the present
invention can indeed substitute for the C85710 lead brass in the
manufacturing of products.
Test Example 6:
A test was performed according to the standard set forth in NSF
61-2007a SPAC for the allowable precipitation amounts of metals in
products, to examine the precipitation amounts of the metals of the brass
alloys in an aqueous environment. Results are shown in Table 4.
Table 4
Precipitation Amounts of the Metals of the Products
Elements Upper Comparative Comparative Example 1
Limit of Example I Example 1
Std. Value (after a
( g/L) lead-stripping
treatment)
Lead 5.0 19.173 0.462 0.352
Bismuth 50.0 0.011 0.006 0.019
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Aluminum 5.0 0.093 0.012 0.273
L Tin 10.0 0.032 0.026 0.053
As shown in Table 4, the precipitation amounts of each of the metals
of the low-lead brass of the present invention were all lower than the
upper limits of the standard values. Thus, the low-lead brass alloy of the
present invention complies with the requirements set forth in NSF
61-2007a SPAC. The lead content of the material of Comparative Example
1 that didn't experience a lead-stripping treatment substantially exceeded
the standard value almost four-fold. However, the material of Example 1
easily met the standard value without experiencing a lead-stripping
treatment. Further, the precipitation amount of lead of Example 1 was still
lower than Comparative Example 1 after a lead-stripping treatment was
performed. Thus, the low-lead brass alloy of the present invention is more
environmentally friendly, and less threatening to human health.
In light of the above, the low-lead copper alloy of the present
invention has mechanical processing properties comparable to those of the
conventional C85710 lead brass. Further, the low-lead copper alloy of the
present invention had better tensile strength and higher production yields
in processing, and can substantially decrease the precipitation amount of
lead in production. Thus, the alloy of the present invention is extremely
suitable for replacing the alloy material of a conventional brass in
manufacturing of products (such as lavatory products (e.g., faucets)).
Moreover, the low-lead copper alloy of the present invention has excellent
resistance to chlorine ions, thereby facilitating production of water supply
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systems for use in an environment with a high concentration of chlorine
ions and facilitating production of copper products for use in a marine
environment.
The invention has been described using exemplary preferred
embodiments. However, it is to be understood that the scope of the
invention is not limited to the disclosed arrangements. The scope of the
claims, therefore, should be accorded the broadest interpretation, so as to
encompass all such modifications and similar arrangements.
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