CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the priority of Chinese Patent Application No.
CN 201611096735.4 filed in China on December 2, 2016, the entire content of which is hereby incorporated
by reference.
FIELD
[0002] The present disclosure relates to the field of alloys, and in particular to a semi-solid
die-casting aluminum alloy and a method for preparing a semi-solid die-casting aluminum
alloy casting.
BACKGROUND
[0003] Die casting is a liquid molding method. Due to the high injection speed, the liquid
easily forms turbulent flow in the mold cavity, and the air in the mold cavity is
drawn into the product. When the liquid hits the mold, the temperature difference
is large, the liquid on the surface is rapidly solidified, which increases the flow
resistance of the core liquid, so it cannot be well fused to form a cold partition.
Due to the introduction of oxides or some other impurities in the alloy smelting and
casting process, the product performance is ultimately lowered.
[0004] With the rapid development of 3C (Computer, communication, and consumer electronics)
and automotive products, die-casting aluminum alloys have been rapidly applied. By
the 1980s, 68% of aluminum alloy components in the United States were produced by
die-casting technology. At present, the die-casting aluminum alloys used in the industry
mainly include aluminum-silicon alloys, aluminum-magnesium alloys, aluminum-zinc alloys,
aluminum-silicon-copper alloys, and aluminum-silicon-magnesium alloys.
[0005] The most commonly used die-casting alloy for die casting is ADC12, which has a yield
strength of about 190 MPa, a tensile strength of about 280 MPa, and an elongation
of 2 to 3%, and cannot be strengthened by heat treatment. The wrought aluminum alloy
(including aluminum alloy for extrusion, forging, rolling, etc.) has high mechanical
properties and stable performance, but due to the harsh process conditions and high
equipment requirements, it is impossible to form complicated parts, and it is impossible
to realize the demands of simplification and integration for automobile parts.
SUMMARY
[0006] An objective of the present disclosure is to provide a semi-solid die-casting aluminum
alloy and a method for preparing a semi-solid die-casting aluminum alloy casting.
The semi-solid die-casting aluminum alloy has high strength and high plasticity, can
be subjected to high pressure casting, and can form various complicated parts and
ensure high mechanical properties.
[0007] To achieve the above objective, the present disclosure provides a semi-solid die-casting
aluminum alloy, containing alloying elements, inevitable impurities and the balance
of an aluminum element; based on the total weight of the semi-solid die-casting aluminum
alloy, the alloying elements include: 7.5 to 9.5 wt% of Si, 3.5 to 4.8 wt% of Cu,
0.5 to 0.75 wt% of Mn, 0.01 to 0.5 wt% of Ti and 0.01 to 0.35 wt% of rare earth element.
[0008] Optionally, based on the total weight of the semi-solid die-casting aluminum alloy,
the alloying elements include: 8.0 to 9.0 wt% of Si, 3.5 to 4.5 wt% of Cu, 0.5 to
0.6 wt% of Mn, 0.05 to 0.25 wt% of Ti and 0.15 to 0.25 wt% of rare earth element.
[0009] Optionally, the rare earth element includes at least one of La, Ce, Pr and Nd.
[0010] Optionally, the impurities in the semi-solid die-casting aluminum alloy are not more
than 0.8 wt%.
[0011] Optionally, the ratio of the weight content of Ti to Cu is 1:(14 to 90).
[0012] Optionally, the semi-solid die-casting aluminum alloy includes 7.5 to 9.5 wt% of
Si, 3.5 to 4.8 wt% of Cu, 0.5 to 0.75 wt% of Mn, 0.01 to 0.5 wt% Ti, 0.01 to 0.35
wt% of rare earth element, no more than 0.8 wt% of impurities and the balance of aluminum.
[0013] Optionally, the semi-solid die-casting aluminum alloy includes 8.0 to 9.0 wt% of
Si, 3.5 to 4.5 wt% of Cu, 0.5 to 0.6 wt% of Mn, 0.05 to 0.25 wt% Ti, 0.15 to 0.25
wt% of rare earth element, no more than 0.7 wt% of impurities and the balance of aluminum.
[0014] Optionally, the semi-solid die-casting aluminum alloy has a tensile strength of not
less than 370 MPa, a yield strength of not less than 290 MPa, and an elongation of
not less than 5.5%.
[0015] Optionally, the semi-solid die-casting aluminum alloy has a tensile strength of not
less than 380 MPa, a yield strength of not less than 300 MPa, and an elongation of
not less than 6%.
[0016] The present disclosure further provides a method for preparing a semi-solid die-casting
aluminum alloy casting, including: after performing ratio smelting on aluminum alloy
raw materials, performing semi-solid die casting to obtain the semi-solid die-casting
aluminum alloy casting; where the aluminum alloy raw materials are such that the obtained
semi-solid die-casting aluminum alloy casting includes: based on the total weight
of the semi-solid die-casting aluminum alloy casting, 7.5 to 9.5 wt% of Si, 3.5 to
4.8 wt% of Cu, 0.5 to 0.75 wt% of Mn, 0.01 to 0.5 wt% of Ti, 0.01 to 0.35 wt% of rare
earth element, and the balance of aluminum and inevitable impurities.
[0017] Optionally, the aluminum alloy raw materials are such that the obtained semi-solid
die-casting aluminum alloy casting includes: based on the total weight of the semi-solid
die-casting aluminum alloy casting, 8.0 to 9.0 wt% of Si, 3.5 to 4.5 wt% of Cu, 0.5
to 0.6 wt% of Mn, 0.05 to 0.25 wt% of Ti, 0.15 to 0.25 wt% of rare earth element,
and the balance of aluminum and inevitable impurities.
[0018] Optionally, the aluminum alloy raw materials are elemental metals or metal alloys.
[0019] Optionally, the aluminum alloy raw materials are elemental aluminum or an alloy of
aluminum, elemental silicon or an alloy of silicon, elemental copper or an alloy of
copper, elemental manganese or an alloy of manganese, elemental titanium or an alloy
of titanium, and an elemental rare earth element or an alloy containing a rare earth
element.
[0020] Optionally, the aluminum alloy raw materials are elemental aluminum, an Al-Si alloy,
an Al-Ti alloy, an Al-Cu alloy, an Al-Mn alloy and an Al-Re intermediate alloy.
[0021] Optionally, the purity of the elemental metal is 99.9 wt% or more, and the total
content of the alloying elements in the metal alloy is 99.9 wt% or more.
[0022] Through the above technical solution, according to the semi-solid die-casting aluminum
alloy of the present disclosure, the adjustment and optimization of the formula and
the addition of rare earth elements have the purification effect of removing gases
and impurities and the modification effect of refining crystal grains on the alloy
melt, and also increase the melt fluidity and enhance the casting properties. The
method for preparing a semi-solid die-casting aluminum alloy casting of the present
disclosure adopts the above semi-solid die-casting aluminum alloy for semi-solid die
casting. The method can form various complicated components, enhances the mechanical
properties of the casting, reduces the defects of the casting, and enhances the yield.
[0023] Other features and advantages of the present disclosure will be described in detail
in the detailed description which follows.
DETAILED DESCRIPTION
[0024] Specific implementations of the present disclosure are described in detail below.
It should be understood that the specific implementations described herein are merely
illustrative of the present disclosure and are not intended to limit the present disclosure.
[0025] The present disclosure provides a semi-solid die-casting aluminum alloy, containing
alloying elements, inevitable impurities and the balance of an aluminum element; based
on the total weight of the semi-solid die-casting aluminum alloy, the alloying elements
include: 7.5 to 9.5 wt% of Si, 3.5 to 4.8 wt% of Cu, 0.5 to 0.75 wt% of Mn, 0.01 to
0.5 wt% of Ti and 0.01 to 0.35 wt% of rare earth element.
[0026] According to the semi-solid die-casting aluminum alloy of the present disclosure,
the adjustment and optimization of the formula and the addition of rare earth elements
have the purification effect of removing gases and impurities and the modification
effect of refining crystal grains on the alloy melt, and also increase the melt fluidity
and enhance the casting properties. According to the semi-solid die-casting aluminum
alloy of the present disclosure, when the composition of the semi-solid die-casting
aluminum alloy is within the above range, high mechanical properties can be obtained
while good casting properties are obtained. The semi-solid die-casting aluminum alloy
obtained by using the formula has a tensile strength of not less than 370 MPa, a yield
strength of not less than 290 MPa, and an elongation of not less than 5.5%.
[0027] According to the present disclosure, to further enhance the mechanical properties
and casting properties of the semi-solid die-casting aluminum alloy, optionally, based
on the total weight of the semi-solid die-casting aluminum alloy, the alloying elements
include: 8.0 to 9.0 wt% of Si, 3.5 to 4.5 wt% of Cu, 0.5 to 0.6 wt% of Mn, 0.05 to
0.25 wt% of Ti and 0.15 to 0.25 wt% of rare earth element. The semi-solid die-casting
aluminum alloy obtained according to the formula has a tensile strength of not less
than 380 MPa, a yield strength of not less than 300 MPa, and an elongation of not
less than 6%.
[0028] According to the present disclosure, the kind of the rare earth element is not particularly
limited, may be a conventional kind well known to those skilled in the art, and may
be a single kind of rare earth element or mixed rare earths. To reduce the raw material
cost, optionally, the rare earth element may include at least one of La, Ce, Pr and
Nd, and the relative content of each rare earth element is also not particularly required.
The above rare earth element may be a commercially available product and is industrial
mixed rare earths.
[0029] According to the present disclosure, the purity of the semi-solid die-casting aluminum
alloy is one of the important factors affecting the performance of the aluminum alloy.
To make the semi-solid die-casting aluminum alloy of the present disclosure excellent
in performance, optionally, the impurities in the semi-solid die-casting aluminum
alloy are not more than 0.8 wt%.
[0030] According to the present disclosure, the addition of the metal element titanium in
the semi-solid die-casting aluminum alloy can refine the crystal grains, enhance the
strength and plasticity of the alloy, improve the fluidity of the alloy and enhance
the casting properties. At the same time, the added metal element copper can form
a Ti
2Cu
3 phase with titanium and be distributed at the grain boundary, so that the grain boundary
slip during alloy stretching is effectively suppressed, thereby enhancing the strength
of the alloy. To further enhance of the effect of enhancing the performance of the
semi-solid die-casting aluminum alloy by the above two elements, optionally, the ratio
of the weight content of Ti to Cu may be 1:(7 to 350), preferably 1:(14 to 90).
[0031] To further enhance the mechanical properties and casting properties of the semi-solid
die-casting aluminum alloy, optionally, the semi-solid die-casting aluminum alloy
may include 7.5 to 9.5 wt% of Si, 3.5 to 4.8 wt% of Cu, 0.5 to 0.75 wt% of Mn, 0.01
to 0.5 wt% Ti, 0.01 to 0.35 wt% of rare earth element, no more than 0.8 wt% of impurities
and the balance of aluminum.
[0032] Optionally, the semi-solid die-casting aluminum alloy may include 8.0 to 9.0 wt%
of Si, 3.5 to 4.5 wt% of Cu, 0.5 to 0.6 wt% of Mn, 0.05 to 0.25 wt% Ti, 0.15 to 0.25
wt% of rare earth element, no more than 0.7 wt% of impurities and the balance of aluminum.
[0033] The present disclosure further provides a method for preparing a semi-solid die-casting
aluminum alloy casting, including: after performing ratio smelting on aluminum alloy
raw materials, performing semi-solid die casting to obtain the semi-solid die-casting
aluminum alloy casting, where the aluminum alloy raw materials are such that the obtained
semi-solid die-casting aluminum alloy casting includes: based on the total weight
of the aluminum alloy casting, 7.5 to 9.5 wt% of Si, 3.5 to 4.8 wt% of Cu, 0.5 to
0.75 wt% of Mn, 0.01 to 0.5 wt% of Ti, 0.01 to 0.35 wt% of rare earth element, and
the balance of aluminum and inevitable impurities.
[0034] According to the method for preparing a semi-solid die-casting aluminum alloy casting
of the present disclosure, to obtain a semi-solid die-casting aluminum alloy casting
having higher mechanical properties, in an optional case, the aluminum alloy raw materials
are such that the obtained semi-solid die-casting aluminum alloy casting includes:
based on the total weight of the semi-solid die-casting aluminum alloy casting, 8.0
to 9.0 wt% of Si, 3.5 to 4.5 wt% of Cu, 0.5 to 0.6 wt% of Mn, 0.05 to 0.25 wt% of
Ti, 0.15 to 0.25 wt% of rare earth element, and the balance of aluminum and inevitable
impurities.
[0035] According to the method for preparing a semi-solid die-casting aluminum alloy casting
of the present disclosure, the melting may be performed in a smelting furnace, and
the aluminum alloy raw materials added to the smelting furnace may be simple substances
or metal alloys, as long as the composition of the aluminum alloy obtained by smelting
the added aluminum alloy raw materials is within the above range. In an optional case,
the aluminum alloy raw materials may be elemental aluminum or an alloy of aluminum,
elemental silicon or an alloy of silicon, elemental copper or an alloy of copper,
elemental manganese or an alloy of manganese, elemental titanium or an alloy of titanium,
and an elemental rare earth element or an alloy containing a rare earth. In an optional
case, the above aluminum alloy raw materials are elemental aluminum, an Al-Si alloy,
an Al-Ti alloy, an Al-Cu alloy, an Al-Mn alloy and an Al-Re intermediate alloy. Further,
to prevent the introduction of impurities from affecting the performance of the aluminum
alloy, the purity of the elemental metal is 99.9 wt% or more, and the total content
of the alloying elements in the alloy is 99.9 wt% or more.
[0036] According to the method for preparing a semi-solid die-casting aluminum alloy casting
of the present disclosure, the semi-solid die-casting aluminum alloy casting is obtained
by performing semi-solid die casting after performing ratio smelting on the aluminum
alloy raw materials. The smelting and semi-solid die casting can employ conventional
methods and operating conditions, and the present disclosure does not impose any particular
requirements.
[0037] For example, the smelting process may adopt the existing steps of material preparation→melting→refining→slag
removing→casting. Specifically, the method for preparing a semi-solid die-casting
aluminum alloy casting of the present disclosure may include the following steps:
Step 1: Material preparation: 1) raw materials: a pure aluminum ingot (purity≥99.9
wt%), an Al-Si intermediate alloy, an Al-Ti intermediate alloy, an Al-Cu intermediate
alloy, an Al-Mn intermediate alloy and an Al-Re intermediate alloy; and 2) fluxes:
a covering agent, a refining agent and a modifier, which may be the existing covering
agent, refining agent and modifier for aluminum alloy preparation, for example, the
covering agent SY-LF1, the refining agent hexachloroethane and the modifier K2ZrF6.
Step 2: Drying: the prepared raw materials are dried, where the pure aluminum ingot
is dried at a temperature of 100°C±10°C, the Al-Si intermediate alloy, the Al-Ti intermediate
alloy, the Al-Cu intermediate alloy, the Al-Mn intermediate alloy and the Al-Re intermediate
alloy are dried at a temperature of 150°C±10°C, and the purpose of drying is to remove
moisture from the raw materials.
Step 3: Melt alloying: the inner wall of a crucible is coated with the prepared covering
agent, the crucible is preheated to 200 to 250°C, the weighed aluminum ingot, Al-Si
intermediate alloy, Al-Ti intermediate alloy, Al-Cu intermediate alloy, Al-Mn intermediate
alloy and Al-Re intermediate alloy ingot are placed into the crucible, and heated
and melted after the addition of the covering agent, and the alloys are stirred uniformly
after fully melted, where the time of the entire melting process is controlled within
2 to 3 h, and the final temperature of the aluminum alloy melt is controlled at 750
to 770°C.
Step 4: Refining: the purpose of refining is to remove non-metallic inclusions in
the alloy liquid; at 700 to 720°C, a bell jar is used to press the refining agent
hexachloroethane into about 2/3 below the surface of the melt in batches, and is rotated
clockwise uniformly and slowly, and when the hexachloroethane is fully reacted, the
inclusions and gases in the melt are taken out. The speed of stirring is low. The
amount of hexachloroethane is related to the alloy composition and the mass of the
original ingot, and is generally 0.5 wt% to 0.7 wt% of the charge. Melting is performed
in a resistance furnace, and the refining time is within 10 min.
Step 5: Slag removing: after fully refining with the hexachloroethane, the bell jar
is taken out, the residual oxides are removed, and the inclusions on the surface of
the melt are removed with a slag spoon.
Step 6: Casting: after the alloy slag is removed, pouring should be immediately performed
after 4 to 10 min of heat preservation to obtain an alloy ingot for die casting or
a die-cast block. The pouring temperature is generally required to be 720 to 750°C.
Step 7: Die Casting: the above-mentioned alloy ingot for die casting or die-cast block
is die-cast into a sample by a conventional semi-solid die casting process, thereby
obtaining the aluminum alloy casting of the present disclosure.
[0038] The aluminum alloy and a method for preparing the same of the present disclosure
are further described below by way of embodiments. However, the present disclosure
is not limited to the embodiments listed below.
[0039] In the following embodiments and comparative embodiments of the present disclosure,
the rare earth element is mixed rare earths (containing 39.8 wt% of La and 58.8 wt%
of Ce).
Embodiment 1
[0040] This embodiment is for explaining a semi-solid die-casting aluminum alloy and a method
for preparing a semi-solid die-casting aluminum alloy casting of the present disclosure.
[0041] The semi-solid die-casting aluminum alloy included: based on the total weight of
the semi-solid die-casting aluminum alloy, 8.5 wt% of Si, 4.0 wt% of Cu, 0.55 wt%
of Mn, 0.15 wt% of Ti, 0.20 wt% of rare earth element, and the balance of aluminum.
[0042] The aluminum ingot, the Al-Si intermediate alloy, the Al-Ti intermediate alloy, the
Al-Cu intermediate alloy, the Al-Mn intermediate alloy and the Al-Re intermediate
alloy ingot measured according to the above semi-solid die-casting aluminum alloy
composition were placed into a crucible coated with a covering agent and preheated
to 220°C, and were heated and melted after the addition of the covering agent, and
the alloys were stirred uniformly after fully melted, where the melting process was
2.5 h, and the final temperature of the aluminum alloy melt was 750°C; at 700 to 720°C,
a bell jar was used to press the refining agent hexachloroethane into about 2/3 below
the surface of the melt in batches, and was rotated clockwise uniformly and slowly,
for refining for 8 min where the amount of hexachloroethane was 0.5 wt% of the charge;
after fully refining, the bell jar was taken out, the residual oxides were removed,
and the inclusions on the surface of the melt were removed with a slag spoon; after
5 min of heat preservation, pouring was performed to obtain an aluminum alloy ingot
Z1, where the pouring temperature was 750°C; and the above aluminum alloy ingot Z1
was die-cast into a sample by a conventional semi-solid die casting process, thereby
obtaining the aluminum alloy casting A1 of this embodiment.
Embodiment 2
[0043] This embodiment is for explaining a semi-solid die-casting aluminum alloy and a method
for preparing a semi-solid die-casting aluminum alloy casting of the present disclosure.
[0044] The method of Embodiment 1 was employed, except that the semi-solid die-casting aluminum
alloy included: based on the total weight of the semi-solid die-casting aluminum alloy,
9.5 wt% of Si, 3.5 wt% of Cu, 0.5 wt% of Mn, 0.01 wt% of Ti, 0.01 wt% of rare earth
element and the balance of aluminum, thereby obtaining the aluminum alloy casting
A2 of this embodiment.
Embodiment 3
[0045] This embodiment is for explaining a semi-solid die-casting aluminum alloy and a method
for preparing a semi-solid die-casting aluminum alloy casting of the present disclosure.
[0046] The method of Embodiment 1 was employed, except that the semi-solid die-casting aluminum
alloy included: based on the total weight of the semi-solid die-casting aluminum alloy,
7.5 wt% of Si, 4.8 wt% of Cu, 0.75 wt% of Mn, 0.5 wt% of Ti, 0.35 wt% of rare earth
element and the balance of aluminum, thereby obtaining the aluminum alloy casting
A3 of this embodiment.
Embodiment 4
[0047] This embodiment is for explaining a semi-solid die-casting aluminum alloy and a method
for preparing a semi-solid die-casting aluminum alloy casting of the present disclosure.
[0048] The method of Embodiment 1 was employed, except that the semi-solid die-casting aluminum
alloy included: based on the total weight of the semi-solid die-casting aluminum alloy,
9.0 wt% of Si, 4.4 wt% of Cu, 0.52 wt% of Mn, 0.10 wt% of Ti, 0.15 wt% of rare earth
element and the balance of aluminum, thereby obtaining the aluminum alloy casting
A4 of this embodiment.
Comparative Embodiment 1
[0049] This comparative embodiment is for explaining a semi-solid die-casting aluminum alloy
and a method for preparing a aluminum alloy casting different from the present disclosure.
[0050] The method and the raw materials of Embodiment 1 were employed except that no rare
earth element was added, thereby obtaining the aluminum alloy casting B1 of this comparative
embodiment.
Comparative Embodiment 2
[0051] This comparative embodiment is for explaining a semi-solid die-casting aluminum alloy
and a method for preparing an aluminum alloy casting different from the present disclosure.
[0052] The method and the raw materials of Embodiment 1 were employed except that the content
of the rare earth element in the semi-solid die-casting aluminum alloy was 0.5 wt%,
thereby obtaining the aluminum alloy casting B2 of this comparative embodiment.
Comparative Embodiment 3
[0053] This comparative embodiment is for explaining a semi-solid die-casting aluminum alloy
and a method for preparing the aluminum alloy casting different from the present disclosure.
[0054] The method and the raw materials of Embodiment 1 were employed except that the content
of the Si in the semi-solid die-casting aluminum alloy was 10 wt%, thereby obtaining
the aluminum alloy casting B3 of this comparative embodiment.
Comparative Embodiment 4
[0055] This comparative embodiment is for explaining a semi-solid die-casting aluminum alloy
and a method for preparing an aluminum alloy casting different from the present disclosure.
[0056] The method and the raw materials of Embodiment 1 were employed except that the content
of the Si in the semi-solid die-casting aluminum alloy was 7 wt%, thereby obtaining
the aluminum alloy casting B4 of this comparative embodiment.
Comparative Embodiment 5
[0057] This comparative embodiment is for explaining a semi-solid die-casting aluminum alloy
and a method for preparing the aluminum alloy casting different from the present disclosure.
[0058] The method and the raw materials of Embodiment 1 were employed except that the content
of the Cu in the semi-solid die-casting aluminum alloy was 5 wt%, thereby obtaining
the aluminum alloy casting B5 of this comparative embodiment.
Comparative Embodiment 6
[0059] This comparative embodiment is for explaining a semi-solid die-casting aluminum alloy
and a method for preparing an aluminum alloy casting different from the present disclosure.
[0060] The method and the raw materials of Embodiment 1 were employed except that the content
of the Cu in the semi-solid die-casting aluminum alloy was 3 wt%, thereby obtaining
the aluminum alloy casting B6 of this comparative embodiment.
Comparative Embodiment 7
[0061] This comparative embodiment is for explaining a semi-solid die-casting aluminum alloy
and a method for preparing an aluminum alloy casting different from the present disclosure.
[0062] The method of Embodiment 1 was employed except that a commercially available ADC12
aluminum alloy ingot was used as the ingot, thereby obtaining the aluminum alloy sample
B7.
Comparative Embodiment 8
[0063] This comparative embodiment is for explaining a semi-solid die-casting aluminum alloy
and a method for preparing an aluminum alloy casting different from the present disclosure.
[0064] The method of Embodiment 1 was employed except that a commercially available A356.2
aluminum alloy ingot was used as the ingot, thereby obtaining the aluminum alloy sample
B8.
Comparative Embodiment 9
[0065] This comparative embodiment is for explaining a die-casting aluminum alloy and a
method for preparing an aluminum alloy casting different from the present disclosure.
[0066] The raw materials of Embodiment 1 were employed except that a conventional die casting
method was used, thereby obtaining the aluminum alloy sample B9.
Comparative Embodiment 10
[0067] This comparative embodiment is for explaining a die-casting aluminum alloy and a
method for preparing an aluminum alloy casting different from the present disclosure.
[0068] Pure aluminum (A00 aluminum), an aluminum-manganese alloy (AlMn10), an aluminum-silicon
alloy (AlSi12), an aluminum-iron alloy (AlFe10), an aluminum-copper alloy (Al-50Cu),
pure magnesium (99.9), pure zinc (99.95), an aluminum-titanium-carbon-boron alloy,
magnesium-lanthanum-cerium (Mg-LaCe) and magnesium-yttrium (Mg-Y) were subjected to
mixture calculation, smelting and pouring. The contents of the main elements of the
finally obtained alloy were as follows: Si: 6.0 wt%, Cu: 0.5 wt%, Fe: 0.42 wt%, Mn:
0.05 wt%, Mg: 1.0 wt%, Zn: 1.5 wt%, Ti: 0.05 wt%, C: 0.002 wt%, LaCe: 0.20 wt%, Y:
0.12 wt%, and the balance of Al and inevitable impurities. A conventional die casting
method was employed to obtain the aluminum alloy sample B10.
Comparative Embodiment 11
[0069] This comparative embodiment is for explaining a die-casting aluminum alloy and a
method for preparing an aluminum alloy casting different from the present disclosure.
- (1) A pure magnesium ingot and intermediate alloys Al-Si, Al-Mn, Al-Cu, Al-Ti were
preheated to 180 to 240°C, the temperature was kept within the range of 740 to 760°C
after pure aluminum was melted, the pure magnesium ingot and the intermediate alloys
Al-Si, Al-Mn, Al-Cu, Al-Ti were sequentially added into the aluminum liquid, and after
being melted, they were kept at 740°C for 30 minutes to be sufficiently homogenized,
where the weight percents of the ingredients in the above materials were Si: 8.5 to
11.5%, Mn: 0.1 to 0.8%, Cu: 0.5 to 3.0%, Mg: 0.25 to 0.5%, Ti: 0.15 to 0.35%, and
other impurities ≤ 0.4% (where Fe<0.8%, P<0.004%).
- (2) The temperature of the alloy liquid was raised to 780°C, the mixed rare earths
were added, the surface scum was removed after the mixed rare earths were melted,
the mixture was stirred for 3 to 6 minutes to homogenize the composition, and after
stirring, the temperature of the alloy liquid was raised to 770 to 780°C, and then
kept to stand for 30 minutes, where the total weight of the mixed rare earths is not
more than 1%, and each of La, Ce, Sm and Nd is less than 0.35% by weight.
- (3) After the alloy liquid was cooled to 750°C and refined for 15 minutes, the alloy
liquid was cooled to 710°C and subjected to slag removal, then the alloy liquid was
cooled to 690°C and subjected to gas removal, finally the alloy liquid after slag
removal and gas removal was cooled to at 680°C and subjected to die casting, and the
heat treatment process was performed after the casting was formed. The casting was
subjected to solution treatment at a temperature of higher than 545°C for 3 hours,
and then subjected to aging treatment at a temperature of 165°C for 6 to 12 hours,
thereby obtaining the aluminum alloy sample B11.
Test
[0070] This test was used to determine the mechanical properties of the semi-solid die-casting
aluminum alloy castings obtained in Embodiments 1 to 4 and Comparative Embodiments
1 to 11 at room temperature.
[0071] For the tensile strength, yield strength and elongation of the aluminum alloy castings
tested with reference to "GB/T 228.1-2010 Metallic Materials-Tensile Testing-Part
1: Method of test at room temperature", the specific results are shown in Table 1.
Table 1
Embodiment |
Yield Strength (MPa) |
Breaking Strength (MPa) |
Elongation (%) |
Embodiment 1 |
310 |
392 |
8.5 |
Embodiment 2 |
300 |
371 |
7.0 |
Embodiment 3 |
291 |
376 |
5.5 |
Embodiment 4 |
305 |
385 |
8.0 |
Comparative Embodiment 1 |
254 |
332 |
5.5 |
Comparative Embodiment 2 |
296 |
367 |
7.0 |
Comparative Embodiment 3 |
280 |
371 |
6.0 |
Comparative Embodiment 4 |
261 |
323 |
5.0 |
Comparative Embodiment 5 |
290 |
342 |
4.0 |
Comparative Embodiment 6 |
243 |
296 |
5.0 |
Comparative Embodiment 7 |
185 |
292 |
2.5 |
Comparative Embodiment 8 |
251 |
310 |
8.0 |
Comparative Embodiment 9 |
174 |
278 |
2 |
Comparative Embodiment 10 |
200 |
300 |
6.2 |
Comparative Embodiment 11 |
230 |
308 |
5.0 |
[0072] It can be seen from the comparison of the results of Embodiments 1 to 4 and Comparative
Embodiments 1 to 11 that the semi-solid die-casting aluminum alloy of the present
disclosure has good mechanical properties and casting properties, and the semi-solid
die-casting aluminum alloy has a tensile strength of not less than 370 MPa, a yield
strength of not less than 290 MPa, and an elongation of not less than 5.5%. In particular,
the optional alloying elements in the present disclosure include: 8.0 to 9.0 wt% of
Si, 3.5 to 4.5 wt% of Cu, 0.5 to 0.6 wt% of Mn, 0.05 to 0.25 wt% of Ti and 0.15 to
0.25 wt% of rare earth element, the semi-solid die-casting aluminum alloy obtained
according to the formula has a tensile strength of not less than 380 MPa, a yield
strength of not less than 300 MPa, and an elongation of not less than 6%. It can be
seen from the comparison of the data of Embodiment 1 and Embodiment 4 with Embodiments
2 to 3 that in the case where the ratio of the weight content of Ti to Cu of the present
disclosure is 1:(14 to 90), the semi-solid die-casting aluminum alloy of the present
disclosure has better mechanical properties and casting properties.
[0073] Although optional implementations of the present disclosure are described in detail
above, the present disclosure is not limited to specific details in the foregoing
implementations. Various variations can be made to the technical solutions of the
present disclosure within the scope of the technical idea of the present disclosure,
and such variations all fall within the protection scope of the present disclosure.
[0074] It should be further noted that the specific technical features described in the
foregoing specific implementations can be combined in any appropriate manner provided
that no conflict occurs. To avoid unnecessary repetition, various possible combination
manners are not further described in the present disclosure.
[0075] In addition, various different implementations of the present disclosure may alternatively
be combined randomly. Such combinations should also be considered as the content disclosed
in the present disclosure provided that these combinations do not depart from the
concept of the present disclosure.
1. A semi-solid die-casting aluminum alloy, containing alloying elements, inevitable
impurities and the balance of aluminum element, wherein based on the total weight
of the semi-solid die-casting aluminum alloy, the alloying elements comprise: 7.5
to 9.5 wt% of Si, 3.5 to 4.8 wt% of Cu, 0.5 to 0.75 wt% of Mn, 0.01 to 0.5 wt% of
Ti and 0.01 to 0.35 wt% of rare earth element.
2. The semi-solid die-casting aluminum alloy according to claim 1, wherein based on the
total weight of the semi-solid die-casting aluminum alloy, the alloying elements comprise:
8.0 to 9.0 wt% of Si, 3.5 to 4.5 wt% of Cu, 0.5 to 0.6 wt% of Mn, 0.05 to 0.25 wt%
of Ti and 0.15 to 0.25 wt% of rare earth element.
3. The semi-solid die-casting aluminum alloy according to claim 1 or 2, wherein the rare
earth element comprises at least one of La, Ce, Pr and Nd.
4. The semi-solid die-casting aluminum alloy according to any one of claims 1 to 3, wherein
the impurities in the semi-solid die-casting aluminum alloy are not more than 0.8
wt%.
5. The semi-solid die-casting aluminum alloy according to any one of claims 1 to 4, wherein
the ratio of the weight content of Ti to Cu is 1:(14 to 90).
6. The semi-solid die-casting aluminum alloy according to any one of claims 1 to 5, wherein
the semi-solid die-casting aluminum alloy comprises 7.5 to 9.5 wt% of Si, 3.5 to 4.8
wt% of Cu, 0.5 to 0.75 wt% of Mn, 0.01 to 0.5 wt% Ti, 0.01 to 0.35 wt% of rare earth
element, no more than 0.8 wt% of impurities and the balance of aluminum.
7. The semi-solid die-casting aluminum alloy according to claim 6, wherein the semi-solid
die-casting aluminum alloy comprises 8.0 to 9.0 wt% of Si, 3.5 to 4.5 wt% of Cu, 0.5
to 0.6 wt% of Mn, 0.05 to 0.25 wt% Ti, 0.15 to 0.25 wt% of rare earth element, no
more than 0.7 wt% of impurities and the balance of aluminum.
8. The semi-solid die-casting aluminum alloy according to any one of claims 1 to 7, wherein
the semi-solid die-casting aluminum alloy has a tensile strength of not less than
370 MPa, a yield strength of not less than 290 MPa, and an elongation of not less
than 5.5%.
9. The semi-solid die-casting aluminum alloy according to claim 2 or 7, wherein the semi-solid
die-casting aluminum alloy has a tensile strength of not less than 380 MPa, a yield
strength of not less than 300 MPa, and an elongation of not less than 6%.
10. A method for preparing a semi-solid die-casting aluminum alloy casting, comprising:
after performing ratio smelting on aluminum alloy raw materials, performing semi-solid
die casting to obtain the semi-solid die-casting aluminum alloy casting, wherein the
aluminum alloy raw materials are such that the obtained semi-solid die-casting aluminum
alloy casting comprises: based on the total weight of the aluminum alloy casting,
7.5 to 9.5 wt% of Si, 3.5 to 4.8 wt% of Cu, 0.5 to 0.75 wt% of Mn, 0.01 to 0.5 wt%
of Ti, 0.01 to 0.35 wt% of rare earth element, and the balance of aluminum and inevitable
impurities.
11. The method according to claim 10, wherein the aluminum alloy raw materials are such
that the obtained semi-solid die-casting aluminum alloy casting comprises: based on
the total weight of the semi-solid die-casting aluminum alloy casting, 8.0 to 9.0
wt% of Si, 3.5 to 4.5 wt% of Cu, 0.5 to 0.6 wt% of Mn, 0.05 to 0.25 wt% of Ti, 0.15
to 0.25 wt% of rare earth element, and the balance of aluminum and inevitable impurities.
12. The method according to claim 10 or 11, wherein the aluminum alloy raw material is
elemental metals or metal alloys.
13. The method according to claim 12, wherein the aluminum alloy raw materials are elemental
aluminum or an alloy of aluminum, elemental silicon or an alloy of silicon, elemental
copper or an alloy of copper, elemental manganese or an alloy of manganese, elemental
titanium or an alloy of titanium, and an elemental rare earth element or an alloy
containing a rare earth element.
14. The method according to claim 12 or 13, wherein the aluminum alloy raw materials are
elemental aluminum, an Al-Si alloy, an Al-Ti alloy, an Al-Cu alloy, an Al-Mn alloy
and an Al-Re intermediate alloy.
15. The method according to any one of claims 12 to 14, wherein the purity of the elemental
metal is 99.9 wt% or more, and the total content of the alloying elements in the metal
alloy is 99.9 wt% or more.