U.S. patent application number 16/234371 was filed with the patent office on 2019-08-08 for frozen forming method for large tailored plate aluminum alloy component.
The applicant listed for this patent is Shijian Yuan. Invention is credited to Shijian Yuan.
Application Number | 20190240716 16/234371 |
Document ID | / |
Family ID | 67475340 |
Filed Date | 2019-08-08 |
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United States Patent
Application |
20190240716 |
Kind Code |
A1 |
Yuan; Shijian |
August 8, 2019 |
FROZEN FORMING METHOD FOR LARGE TAILORED PLATE ALUMINUM ALLOY
COMPONENT
Abstract
A frozen forming method for a large-size thin-walled aluminum
alloy component using an aluminum alloy tailor-welded plate is
described. An aluminum alloy tailor-welded plate is cooled to a
temperature with a cryogenic fluid medium, and temperature of a
weld zone is regulated to be lower than that of a base metal zone;
and the component is fabricated by a tool integrally with aluminum
alloy tailor-welded plate, by placing aluminum alloy tailor-welded
plate onto tool; assembling tool and filling with cryogenic fluid
medium so temperature of tool is -150 to -196 degrees Celsius; and
apply pressure to deform the aluminum alloy tailor-welded plate
when temperature of a weld zone reaches -150 degrees Celsius to
-196 degrees Celsius, thereby facilitating forming the aluminum
alloy tailor-welded plate to a designed shape of the aluminum alloy
component; and disassembling the tool, and taking out the aluminum
alloy component.
Inventors: |
Yuan; Shijian; (Harbin,
CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Yuan; Shijian |
Harbin |
|
CN |
|
|
Family ID: |
67475340 |
Appl. No.: |
16/234371 |
Filed: |
December 27, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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PCT/CN2018/000188 |
May 23, 2018 |
|
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|
16234371 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B21D 37/16 20130101;
C22F 1/04 20130101; B21D 37/10 20130101; B21D 22/22 20130101; B21D
35/006 20130101; B21D 22/205 20130101; B21D 35/005 20130101 |
International
Class: |
B21D 37/16 20060101
B21D037/16; C22F 1/04 20060101 C22F001/04; B21D 22/22 20060101
B21D022/22; B21D 37/10 20060101 B21D037/10 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 8, 2018 |
CN |
201810126112.X |
Claims
1. A frozen forming method for an aluminum alloy component,
comprising of: cooling an aluminum alloy tailor-welded plate with a
cryogenic fluid medium, and forming the aluminum alloy plate into a
complex shape component by a tool, and the frozen forming method
further comprising the steps of: step 1, placing the aluminum alloy
tailor-welded plate onto the tool; step 2, assembling the tool and
filling the tool with the cryogenic fluid medium so that the
temperature of the tool drops to -150 degrees Celsius to -196
degrees Celsius; step 3, deforming the aluminum alloy tailor-welded
plate by applying pressure with the tool when the temperature of a
weld zone of the aluminum alloy tailor-welded plate reaches -150
degrees Celsius to -196 degrees Celsius and is lower than the
temperature of a base metal zone, that is a temperature difference
delta T occurs between the weld zone and the base metal zone,
thereby forming the aluminum alloy tailor-welded plate to a
designed shape of the aluminum alloy component; and step 4,
disassembling the tool, and taking out the aluminum alloy
component.
2. The frozen forming method for the aluminum alloy component
structure of claim 1, wherein in the step 3 the temperature
difference between the weld zone and the base metal zone is not
less than 30 degrees Celsius.
3. The frozen forming method for the aluminum alloy component of
claim 2, wherein the aluminum alloy tailor-welded plate is one of
an Al--Cu--Mg alloy plate, an Al--Cu--Mn alloy plate, an Al--Mg--Si
alloy plate, an Al--Zn--Mg--Cu alloy plate and an Al--Cu-Li alloy
plate.
4. The frozen forming method for the aluminum alloy component of
claim 2, wherein the aluminum alloy tailor-welded plate is prepared
by friction stir welding technology.
5. The frozen forming method for the aluminum alloy component of
claim 4, wherein the cryogenic fluid medium is a cooling medium for
cryogenic temperature, and is either liquid nitrogen or liquid
helium.
6. The frozen forming method for the aluminum alloy component of
claim 1, wherein a solution treatment is conducted on the aluminum
alloy tailor-welded plate before the step 1, and an artificial
aging treatment is conducted on the aluminum alloy component after
the step 4.
7. The frozen forming method for the aluminum alloy component claim
1, wherein the tool comprises at least one cooling chamber, and the
cooling chamber is disposed as a portion of the tool, where the
weld zone is located, and is used for cooling.
8. The frozen forming method for the aluminum alloy component claim
7, wherein in the step 2, the temperature of the tool is regulated
via a control device, and the control device is connected with the
cooling chamber, and further controlling of the temperature of the
cooling chamber is by regulating the flow of the cryogenic fluid
medium.
9. The frozen forming method for the aluminum alloy component of
claim 8, wherein the tool is further provided with a thermal
insulating layer.
10. The frozen forming method for the aluminum alloy component of
claim 9, wherein the tool is provided with a cooling channel, and
the cooling channel is disposed as a portion of the tool, where the
weld zone of the aluminum alloy tailor-welded plate is located.
11. The frozen forming method for the aluminum alloy component of
claim 4, wherein the aluminum alloy tailor-welded plate having a
thickness of between 2 mm to 8 mm, and made from an aluminum alloy
plate having a diameter of 2700 mm to 4200 mm.
Description
TECHNICAL FIELD
[0001] The present invention relates to the technical field of
sheet metal forming, and in particular to a forming method at
cryogenic temperature for a large-size component using an aluminum
alloy tailor-welded plate.
BACKGROUND ART
[0002] Aluminum alloy, featuring excellent specific strength,
specific stiffness and corrosion resistance, has been one of
primary structural materials for aerospace equipment such as a
rocket and an aircraft. The aluminum alloy accounts for about 80%
of the structural mass of a carrier rocket and above 50% of the
structural mass of a civil aircraft. With the development of a new
generation of large rockets and aircrafts, an urgent need emerges
for large-sized integral structure comprising aluminum alloy
thin-walled components to meet their requirements for higher
reliability, longer lifespan and lighter weight.
[0003] An existing technical roadmap for manufacturing aluminum
alloy thin-walled component was presented as "sheet metal forming
separately, welding into an integral component and heat treatment
for property control" in one prior art literature. The prior art
has the main problems that a relatively high degree of distortion
is caused after welding, and an even greater distortion is caused
after the heat treatment. What's more, the integral thin-walled
component can't be subjected to shape correction after forming and
welding, and the prior art method usually leads to lower precision
and a failure to meet the use requirements. In order to solve the
problems above, a technical roadmap to be adopted is "sheet metal
tailor-welding for preparing a large-size tailor-welded plate, heat
treatment for property control and integral forming using the
large-size tailor-welded plate for a large-size thin-walled
component". For the advantage of high strength coefficient of weld
joint, friction stir welding (FSW) has become a preferred welding
method for aluminum alloy components in the aerospace field in
recent years, instead of fusion welding methods such as arc welding
and laser welding. Therefore, there is an urgent need for
development of a large-size integral component forming technology
using aluminum alloy FSW tailor-welded plate.
[0004] However, there are some insuperable difficulties for forming
the larger-sized aluminum alloy thin-walled integral component by
an existing conventional cold forming (forming at room temperature)
technology and a hot forming (forming at elevated temperature)
technology. As to the cold forming technology, a larger-sized
thin-walled tailor blank is prone to wrinkle and a FSW weld joint
is prone to crack when a conventional deep drawing technique is
adopted, thus both the wrinkling and cracking defects exist and
can't be overcome. Sheet hydroforming has been looked as a
promising cold forming technology for large-size thin-walled
component with curved surface. However, the forming force of a
component with the diameter of 5 m reaches 800 MN, and the cost and
risk of super-large fluid high pressure forming equipment are
extremely high when sheet hydroforming technique is adopted. As to
the hot forming technology, the FSW weld joint is softened in
heating status, and the cracking problem can't be solved for the
lower strength caused by softened weld joint in the forming
process. Furthermore, there are very difficult to control the
microstructure and mechanical properties of the formed component in
the hot forming process.
[0005] In order to solve the problems when the larger-sized
aluminum alloy integral thin-walled component is manufactured with
the traditional forming technologies, a method called frozen
forming technology is invented for forming of larger-sized aluminum
alloy tailor-welded component at very low temperature by utilizing
a new phenomenon that the aluminum alloy sheet is enhanced both on
plasticity and strength at a very low temperature as described
herein below.
SUMMARY OF THE INVENTION
[0006] The present invention provides a frozen forming method for
an aluminum alloy tailor-welded component to overcome the defects
in the prior art aluminum alloy components fabricated. An
embodiment of the present invention is as follows: the frozen
forming method includes steps of cooling an aluminum alloy
tailor-welded plate to a temperature within an appropriate very low
temperature range with a cryogenic fluid medium, and forming the
aluminum alloy tailor-welded component with a set of tool (the tool
is usually comprised by a punch, a die and a blank-holder, and so
on), and particularly includes the following steps of: [0007] step
1, the aluminum alloy tailor-welded plate prepared by FSW is placed
onto the tool; [0008] step 2, the tool is assembled and the tool is
filled with the cryogenic fluid medium so that the temperature of
the tool drops to -150 degrees Celsius to -196 degrees Celsius;
[0009] step 3, the punch of the tool is allowed to apply pressure
on the aluminum alloy tailor-welded plate when the temperature of a
weld zone of the aluminum alloy tailor-welded plate reaches -150
degrees Celsius to -196 degrees Celsius and the temperature of the
weld zone is lower than the temperature of a base metal zone, that
is a temperature difference delta T occurs between the weld zone
and the base metal zone, thereby the aluminum alloy tailor-welded
component is deformed; and [0010] step 4, the tool assembled in
step 2 is disassembled in this step , and the aluminum alloy
tailor-welded component is taken out, thereby it is completed for
the frozen forming of the aluminum alloy tailor-welded
component.
[0011] Preferably, in the step 3 the temperature difference between
the weld zone and the base metal zone is not less than 30 degrees
Celsius.
[0012] Preferably, the aluminum alloy tailor-welded plate is one of
an Al--Cu--Mg alloy plate, an Al--Cu--Mn alloy plate, an Al--Mg--Si
alloy plate, an Al--Zn--Mg--Cu alloy plate and an Al--Cu--Li alloy
plate.
[0013] Preferably, the large-size aluminum alloy tailor-welded
plate is prepared by a friction stir welding technology.
[0014] Preferably, the cryogenic fluid medium is a cooling medium
for low temperature, and is, for example, either liquid nitrogen or
liquid helium.
[0015] Preferably, solution treatment is conducted on the aluminum
alloy tailor-welded plate before the step 1, and artificial aging
treatment is conducted on the aluminum alloy tailor-welded
component after the step 4.
[0016] Preferably, the tool comprises at least one cooling chamber,
and the cooling chamber is disposed at a portion, where the weld
zone is located, in the tool, and is used for cooling.
[0017] Preferably, in the step 2, the temperature of the tool is
regulated through a control device, and the control device is
connected with the cooling chamber, and the temperature of the
cooling chamber is further controlled by regulating the flow of the
cryogenic fluid medium.
[0018] Preferably, the tool is further provided with cold
insulation and preservation layers.
[0019] Preferably, the tool is provided with a cooling channel, and
the cooling channel is disposed below the aluminum alloy
tailor-welded plate.
[0020] Compared with the prior art, the present invention has some
beneficial effects which include the following aspects: 1) The
cracking problem caused by a high degree of deformation in the weld
zone can be avoided by utilizing the feature that the plasticity
and the strength of the weld zone are higher than the plasticity
and the strength of the base metal zone, which is caused by the
temperature difference on the aluminum alloy tailor-welded plate at
cryogenic temperature; 2) The microstructure damages can be avoided
and restored to original microstructure status after forming of
aluminum alloy tailor-welded component by the frozen forming
method. As a result, the microstructure and mechanical properties
of the aluminum alloy tailor-welded component are minimally changed
by the forming at the cryogenic temperature range; and 3) Frozen
lubricating layers are formed at working surfaces between the
tailor-welded plate and the tool, which can reduce friction force
and forming force during flowing of the plate, as well as the
tonnage and cost of forming equipment.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] In order to more clearly illustrate the technical schemes in
embodiments of the present invention, the drawings to be used in
the embodiments will be simply introduced as follows.
[0022] FIG. 1 is a schematic diagram of initial status/setup of
frozen forming using an aluminum alloy FSW tailor-welded plate,
where a tool is provided with a cooling channel, according to an
embodiment of the present invention.
[0023] FIG. 2 is a schematic diagram of initial status/setup of
frozen forming for a flat-bottom cylindrical component using the
aluminum alloy FSW tailor-welded plate in embodiment of Example 1
of the present invention;
[0024] FIG. 3 is a schematic diagram of final status of frozen
forming for a flat-bottom cylindrical component using the aluminum
alloy FSW tailor-welded plate in Example 1 of the present
invention;
[0025] FIG. 4 is a schematic diagram of a flat-bottom cylindrical
component structure by frozen forming using the aluminum alloy FSW
tailor-welded plate in Example 1 of the present invention;
[0026] FIG. 5 is a schematic diagram of initial status/step of
frozen forming for a hemispherical component using an aluminum
alloy FSW tailor-welded plate in Example 3 of the present
invention;
[0027] FIG. 6 is a schematic diagram of final status of frozen
forming for the hemispherical component structure using the
aluminum alloy FSW tailor-welded plate in Example 3 of the present
invention;
[0028] FIG. 7 is a hemispherical component structure diagram by
frozen forming using the aluminum alloy FSW tailor-welded plate in
Example 3 of the present invention;
[0029] FIG. 8 is a schematic diagram of initial status of frozen
forming for a -shaped component using an aluminum alloy FSW
tailor-welded plate in Example 5 of the present invention;
[0030] FIG. 9 is a schematic diagram of final status of frozen
forming for a -shaped component using the aluminum alloy FSW
tailor-welded plate in Example 5 of the present invention;
[0031] FIG. 10 is an -shaped component structure fabricated by
frozen forming using the aluminum alloy FSW tailor-welded plate in
Example 5 of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0032] The above-mentioned and other technical features and
advantages of the present invention will be further described in
detail below in conjunction with the accompanying drawings.
[0033] Please refer to FIG. 1. FIG. 1 is a schematic diagram of
initial status, or setup of cryogenic/freezing forming using an
aluminum alloy friction stir welding (FSW) tailor-welded plate,
where a tool is provided with a cooling channel, according to an
embodiment of the present invention.
[0034] The present invention provides a first embodiment of a
frozen forming method for an aluminum alloy tailor-welded component
structure. An aluminum alloy tailor-welded plate 4 is prepared by
friction stir welding (FSW) technology. The frozen forming method
according to a first embodiment of the present invention is as
follows: the aluminum alloy tailor-welded plate 4 is cooled to a
temperature within an appropriate very low temperature range with a
cryogenic fluid medium, and a aluminum alloy tailor-welded flat
bottom cylindrical component 7 is formed by a tool. For the sake of
simplicity, the aluminum alloy tailor-welded flat bottom
cylindrical component 7 is also referred to as the aluminum alloy
tailor-welded component 7 in the following descriptions.
[0035] The additional/further specific steps for the frozen forming
method in example 1 are as follows in these steps: step 1, the
aluminum alloy tailor-welded plate is placed onto the tool; [0036]
step 2, the tool is assembled and filled with the cryogenic fluid
medium so that the temperature of the tool drops to -150 degrees
Celsius to -196 degrees Celsius; step 3, the tool is allowed to
apply pressure to deform the aluminum alloy tailor-welded plate
when the temperature of a weld zone 42 of the aluminum alloy
tailor-welded plate reaches -150 degrees Celsius to -196 degrees
Celsius and the temperature of the weld zone 42 is lower than the
temperature of a base metal zone 41, that is a temperature
difference delta T occurs between the weld zone 42 and the base
metal zone 41, thereby forming the aluminum alloy tailor-welded
component 7; and step 4, the tool assembled in the step 2 is now
disassembled, and the aluminum alloy tailor-welded component 7 is
taken out, thereby completing the frozen forming of the aluminum
alloy tailor-welded component 7.
[0037] The frozen forming method for the large-size aluminum alloy
tailor-welded component involves a frozen forming device. The
frozen forming device includes a set of tool (not labelled, but
shown in FIGS. 1-3, respectively); the tool includes a punch 33, a
die 31, a blank holder 32; the die 31 is disposed at a lower
portion of the tool; the blank holder 32 is disposed at a middle
portion of the tool; and the die 33 is disposed at an upper portion
of the tool and is used for applying pressure to the aluminum alloy
tailor-welded plate 4 so as to facilitate the forming of the
aluminum alloy tailor-welded plate 4. Moreover, a first thermal
insulation layer 61 and a second thermal insulation layer 62 are
disposed in the tool so as to reduce cold/thermal exchange or
cold/thermal conduction between the tool and the outside, thus
avoiding loss of refrigeration capacity, and improving the cooling
effect of the tool. Moreover, a groove 35 is reserved at a contact
surface of the tool and the aluminum alloy tailor-welded plate 4,
and is used for storing ice, thus can be also called an ice groove.
Moreover, a cooling chamber 34 is disposed in a portion of the
tool, disposed at below the weld zone 42 of the aluminum alloy
tailor-welded plate 4, of the die 31, and is used for cooling.
[0038] The frozen forming device further includes a first
temperature sensor 51, a second temperature sensor 52, a cryogenic
fluid medium storage tank 2 and a control device (not labeled); the
first temperature sensor 51 and the second temperature sensor 52
are used for monitoring the temperature of the weld zone 42 and the
temperature of the base metal zone 41, respectively; the cryogenic
fluid medium storage tank 2 is used for storing the cryogenic fluid
medium; the control device includes a first control valve 11 and a
second control valve 12 which are connected with the cryogenic
fluid medium storage tank 2 and the cooling chamber 34,
respectively, and used for regulating a flow of the cryogenic fluid
medium to further control the temperature of the cooling chamber
34.
[0039] As a preferred embodiment, a cooling channel 8 is disposed
in the tool and the cooling channel 8 is disposed below the
aluminum alloy tailor-welded plate 4, so that the cryogenic fluid
medium is prevented from being in direct contact with the aluminum
alloy tailor-welded plate 4, evaporation and loss of the cryogenic
fluid medium are reduced, and the cryogenic fluid medium can be
recycled in the (sealed) cooling channel 8 conveniently.
EXAMPLE 1
[0040] Please refer to FIG. 2, FIG. 3 and FIG. 4. FIG. 2 is a
schematic diagram of initial status/setup of frozen forming for a
flat-bottom cylindrical component 7 using the aluminum alloy (FSW)
tailor-welded plate 4 in this illustrated example 1; For the sake
of simplicity, the tailor-welded flat bottom cylindrical component
7 is also called the aluminum alloy tailor-welded component 7 and
the flat-bottom cylindrical component 7 in the following
descriptions. FIG. 3 is a schematic diagram of final status of
frozen forming method for the flat-bottom cylindrical component 7
using the aluminum alloy (FSW) tailor-welded plate 4 in this
example 1; FIG. 4 shows a flat-bottom cylindrical component 7
fabricated by frozen forming using the aluminum alloy FSW
tailor-welded plate 4 in this example 1; The example 1 provides a
freeze-forming method for a flat-bottom cylindrical component 7
using the aluminum alloy FSW tailor-welded plate 4 which is of a
large-size, wherein an aluminum alloy plate is an Al--Cu--Mn alloy,
and particularly an annealing status 2219 aluminum alloy
tailor-welded plate with a thickness of 6 mm. Parameters for
friction stir welding performed on the aluminum alloy plate are as
follows: the welding advancing speed is 300 mm/min and the welding
rotating speed is 800 rpm; and the diameter of a circular blank is
2700 mm and one weld joint is located at a symmetric axis of the
aluminum alloy plate. A flat-bottom cylindrical rigid tool with the
diameter of 2250 mm is adopted, and includes a die 33, a punch 31
and a blank holder 32, wherein a cooling chamber 34 is preset in
the die 31. The additional/further specific steps for the frozen
forming process while above friction stir welding process is also
performed on the aluminum alloy plate are as follows: [0041] step
1, placing the 2219 aluminum alloy tailor-welded plate 4 onto the
tool and allowing a weld zone 42 to be located above the cooling
chamber 34 of the die; [0042] step 2, filling the cooling chamber
34 of the die with the cryogenic fluid medium so that the
temperature of the cooling chamber 34 of the die drops to -150
degrees Celsius; [0043] step 3, assembling the blank holder 32 and
the punch 33, allowing the blank holder 32 to apply pressure of 3
MPa, regulating the flow of the cryogenic fluid medium through the
first control valve 11 and the second control valve 12, and
allowing the punch 33 to descend to apply drawing force to deform
the 2219 aluminum alloy tailor-welded plate 4 when the temperature
of the weld zone 42 of the 2219 aluminum alloy tailor-welded plate
4 reaches -150 degrees Celsius and the temperature of the base
metal zone 41 is higher than -120 degrees Celsius, thereby forming
a flat-bottom cylindrical component 7 using the 2219 aluminum alloy
tailor-welded plate 4; and [0044] step 4, separating the punch 33,
the blank holder 32 and the die 31, and taking out the flat-bottom
cylindrical component 7 deformed using the 2219 aluminum alloy
tailor-welded plate 4, thereby completing the frozen forming
process of the 2219 aluminum alloy tailor-welded plate (that is
also prepared by a concurrent friction stir welding process) for
fabricating a flat-bottom cylindrical component 7. The cryogenic
fluid medium is a very low temperature cooling medium, and is
either liquid nitrogen or liquid helium.
[0045] By utilizing the feature that the plasticity and the
strength of the weld zone are higher than the plasticity and the
strength of the base metal zone caused by temperature difference on
the aluminum alloy tailor-welded plate, the aluminum alloy
tailor-welded plate can be deformed at a very low temperature. So,
the cracking problem caused by a high degree of deformation in the
weld zone can be avoided; the flat-bottom cylindrical component
formed using the aluminum alloy tailor-welded plate in the example
1 can avoid microstructure damage and restore to original
microstructure status after being formed, the mechanical property
of the flat-bottom cylindrical component is basically not changed
by the forming at the very low cryogenic temperature range. In the
example 1 of freeze-forming process of the flat-bottom cylindrical
component with aluminum alloy tailor-welded plate, frozen
lubricating layers are formed at working surfaces between the
tailor-welded plate and the tool, which can reduce friction force
during flowing of the blank while the performing the FSW process,
thereby reducing forming force, and greatly reducing the tonnage
and cost of forming equipment.
EXAMPLE 2
[0046] This example provides a frozen forming method for a
flat-bottom cylindrical component structure, also referred to as
flat-bottom cylindrical component herein below, using an aluminum
alloy FSW tailor-welded plate, and differs from Example 1 in that
the aluminum alloy plate is an Al--Cu--Mg alloy, and particularly
an annealing status 2024 aluminum alloy tailor-welded plate with a
thickness of 7 mm. Parameters for friction stir welding performed
on the aluminum alloy plate are as follows: the welding advancing
speed is 200 mm/min and the welding rotating speed is 1000 rpm; and
the diameter of a circular blank is 2700 mm and one weld joint is
located at a symmetric axis of the aluminum alloy plate. A
flat-bottom cylindrical rigid tool with the diameter of 2250 mm is
adopted, and includes a punch 33, a die 31 and a blank holder 32,
wherein a cooling chamber 34 is preset in the die 31. The further
specific steps for the frozen forming process of example 2 are as
follows: [0047] step 1, placing the 2024 aluminum alloy
tailor-welded plate 4 onto the tool and allowing a weld zone 42 to
be located above the cooling chamber 34 of the die; [0048] step 2,
filling the cooling chamber 34 of the die with a cryogenic fluid
medium so that the temperature of the cooling chamber 34 of the die
drops to -172 degrees Celsius; [0049] step 3, assembling the blank
holder 32 and the punch 33, allowing the blank holder 32 to apply 3
MPa pressure, regulating the flow of the cryogenic fluid medium
through the first control valve 11 and the second control valve 12,
and allowing the punch 33 to descend to apply drawing force to
deform the 2024 aluminum alloy tailor-welded plate 4 when the
temperature of the weld zone 42 of the 2024 aluminum alloy
tailor-welded plate 4 reaches -172 degrees Celsius and the
temperature of the base metal zone 41 is higher than -142 degrees
Celsius, thereby forming a flat-bottom cylindrical component 7
using the 2024 aluminum alloy tailor-welded plate 4; and [0050]
step 4, separating the punch 33, the blank holder 32 and the die
31, and taking out the flat-bottom cylindrical component 7, thereby
completing frozen forming of the flat-bottom cylindrical component
7 of the 2024 aluminum alloy tailor-welded plate 4. The cryogenic
fluid medium is a very low temperature cooling medium, and is
either liquid nitrogen or liquid helium, for example.
[0051] By utilizing the feature that the plasticity and the
strength of the weld zone are higher than the plasticity and the
strength of the base metal zone caused by temperature difference on
the aluminum alloy tailor-welded plate, the cracking problem caused
by a high degree of deformation in the weld zone can be avoided.
The flat-bottom cylindrical component of aluminum alloy
tailor-welded plate formed in the example can avoid microstructure
damage and restore to original microstructure status after being
formed, the microstructure and mechanical property are basically
not changed by the forming at the very low temperature; and in the
example of frozen forming process for flat-bottom cylindrical
component with the aluminum alloy tailor-welded plate, frozen
lubricating layers are formed at working surfaces between the
tailor-welded plate and the tool, which can reduce frictional force
during flowing of the blank, reduce forming force, and greatly
reduce the tonnage and cost of forming equipment.
EXAMPLE 3
[0052] Please refer to FIG. 5, FIG. 6 and FIG. 7. FIG. 5 is a
schematic diagram of initial status of frozen forming for a
hemispherical (aluminum alloy tailor-welded) component 7 using an
aluminum alloy FSW tailor-welded plate in Example 4 of the present
invention; FIG. 6 is a schematic diagram of final status of frozen
forming for the hemispherical (aluminum alloy tailor-welded)
component 7 using the aluminum alloy FSW tailor-welded plate in
Example 4 of the present invention; FIG. 7 shows a hemispherical
(aluminum alloy tailor-welded) component 7 fabricated by frozen
forming using the aluminum alloy FSW tailor-welded plate in Example
4 of the present invention The example 3 provides a frozen forming
method for a hemispherical component using an aluminum alloy FSW
tailor-welded plate, wherein an aluminum alloy plate is an
Al--Cu--Mn alloy, and particularly an annealing status 2219
aluminum alloy tailor-welded plate with the thickness of 8 mm.
Parameters for friction stir welding performed on the aluminum
alloy plate are as follows: the welding advancing speed is 300
mm/min and the welding rotating speed is 800 rpm; the diameter of a
circular blank is 4200 mm; two weld joints are located at two
sides, 1750 mm far away from a symmetric axis of the blank
respectively; and a semi-ellipsoidal rigid tool with the diameter
of 3350 mm is adopted, and includes a punch 33, a die 31 and a
blank holder 32, wherein cooling chambers 34 are preset in the die
31. The further specific steps for frozen forming method for
example 3 are as follows: [0053] step 1, conducting solution
treatment on the aluminum alloy tailor-welded plate 4, heating a
solid solution to 535 degrees Celsius by a box type heating
furnace, placing in the aluminum alloy tailor-welded plate 4 for
heat preservation for 45 minutes, then taking the aluminum alloy
tailor-welded plate 4 out and conducting rapid water quenching on
the aluminum alloy tailor-welded plate 4; [0054] step 2, placing
the 2219 aluminum alloy tailor-welded plate 4 onto the tool and
allowing weld zones 42 to be located above the cooling chambers 34
of the die; [0055] step 3, filling the cooling chambers 34 of the
die with the cryogenic fluid medium so that the temperatures of the
cooling chambers 34 of the die drop to -180 degrees Celsius; [0056]
step 4, assembling the blank holder 32 and the punch 33, allowing
the blank holder 32 to apply pressure of 3 MPa, regulating the flow
of the cryogenic fluid medium through the first control valve 11
and the second control valve 12, and allowing the punch 33 to
descend to apply drawing force to deform the 2219 aluminum alloy
tailor-welded plate 4 when the temperatures of the weld zones 42 of
the 2219 aluminum alloy tailor-welded plate 4 reach -180 degrees
Celsius and the temperature of the base metal zone 41 is higher
than -150 degrees Celsius, thereby forming a hemispherical
(aluminum alloy tailor-welded) component 7 using the 2219 aluminum
alloy tailor-welded plate 4; [0057] step 5, separating the punch
33, the blank holder 32 and the die 31, and taking out the
hemispheric component 7, thereby completing frozen forming of
hemispheric component 7 with the 2219 aluminum alloy tailor-welded
plate 4; and [0058] step 6, conducting artificial aging treatment
on the (thin-walled) hemispherical component 7, placing the
hemispherical component 7 in an aging furnace for heat preservation
at 175 degrees Celsius for 18 hours, then taking the hemispherical
component 7 out, and air cooling the hemispherical component to the
room temperature. The cryogenic fluid medium is a very low
temperature cooling medium, and is either liquid nitrogen or liquid
helium.
[0059] By utilizing the feature that the plasticity and the
strength of the weld zone are higher than the plasticity and the
strength of the base metal zone caused by temperature difference on
aluminum alloy tailor-welded plate at a very low temperature, the
cracking problem caused by high degrees of deformation in the weld
zones can be avoided and restore to original microstructure status
after being formed. The aluminum alloy tailor-welded plate
hemispheric component formed in the example can avoid
microstructure damage and restore to original microstructure status
after being formed, the microstructure and mechanical property are
basically not changed by the forming at the very low temperature.
In the example of the freeze-forming process of the hemispheric
component, frozen lubricating layers are formed at working surfaces
between the tailor-welded plate and the tool, which can reduce
friction force during flowing of the blank, reduce forming force,
and greatly reduce the tonnage and cost of forming equipment.
EXAMPLE 4
[0060] This example provides a frozen forming method for a
hemispherical shaped component (structure) fabricated from an
aluminum alloy FSW tailor-welded plate, and differs from Example 3
in that wherein an aluminum alloy plate is an Al--Mg--Si alloy, and
particularly a quenching status 6016 aluminum alloy tailor-welded
plate with the thickness of 6 mm. Parameters for friction stir
welding performed on the aluminum alloy plate are as follows: the
welding advancing speed is 400 mm/min and the welding rotating
speed is 1200 rpm; the diameter of a circular slab is 4200 mm; two
weld joints are located at two sides, 1750 mm far away from a
symmetric axis of the slab respectively; and a semi-ellipsoidal
rigid tool with the diameter of 3350 mm is adopted., and includes a
punch 33, a die 31 and a blank holder 32, wherein a plurality of
cooling chambers 34 are preset in the die 31. The further specific
steps for frozen forming method in example 4 are as follows: step
1, placing the 6016 aluminum alloy tailor-welded plate 4 onto the
tool and allowing weld zones 42 to be located above the cooling
chambers 34 of the die; step 3, filling the cooling chambers 34 of
the die with the cryogenic fluid medium so that the temperatures of
the cooling chambers 34 of the die drop to -160 degrees Celsius;
step 4, assembling the blank holder 32 and the punch 33, allowing
the blank holder 32 to apply pressure of 3 MPa, regulating the flow
of the cryogenic fluid medium through the first control valve 11
and the second control valve 12, and allowing the punch 33 to
descend to apply drawing force to deform the 6016 aluminum alloy
tailor-welded plate 4 when the temperatures of the weld zones 42 of
the 6016 aluminum alloy tailor-welded plate 4 reach -160 degrees
Celsius and the temperature of the base metal zone 41 is higher
than -130 degrees Celsius, thereby forming a 6016 aluminum alloy
tailor-welded plate hemispherical component; step 5, separating the
punch 33, the blank holder 32 and the die 31, and taking out the
hemispherical component, thereby completing the frozen forming of
the hemispherical component 7; and step 6, conducting artificial
aging treatment on the (thin-walled) hemispherical component 7, and
placing the hemispherical component 7 in an aging furnace for heat
preservation at 175 degrees Celsius for 20 minutes, then taking the
hemispherical component 7 out and air cooling the hemispherical
component 7 to the room temperature. The cryogenic fluid medium is
a very low temperature cooling medium, and is either liquid
nitrogen or liquid helium.
[0061] By utilizing the feature that the plasticity and the
strength of the weld zone are higher than the plasticity and the
strength of the base metal zone, caused by temperature difference
on aluminum alloy tailor-welded plate at a very low temperature,
the cracking problem caused by high degrees of deformation in the
weld zones can be avoided and restore to original microstructure
status after being formed. The hemispheric component formed using
aluminum alloy tailor-welded plate in the example can avoid
internal microstructure damage, the structure property is basically
not changed by the forming at the very low temperature. In the
example of the freeze-forming process of hemispheric component with
the aluminum alloy tailor-welded plate, frozen lubricating layers
are formed at working surfaces between the tailor-welded plate and
the tool, which can reduce frictional resistance during flowing of
the blank, reduce forming force, and greatly reduce the tonnage and
cost of forming equipment.
[0062] Example 5 Please refer to FIG. 8, FIG. 9 and FIG. 10 for
illustrating of Example 5. FIG. 8 is a schematic diagram of initial
status of frozen forming for an -shaped component with an aluminum
alloy FSW tailor-welded plate in this example; FIG. 9 is a
schematic diagram of final status of frozen forming for an -shaped
component with the aluminum alloy FSW tailor-welded plate in this
example; FIG. 10 is an -shaped component structure diagram of
freeze-forming of the aluminum alloy FSW tailor-welded plate in
this example. The example provides a frozen forming method of an
-shaped component with an aluminum alloy FSW tailor-welded plate,
wherein an aluminum alloy plate is an Al--Cu--Li alloy, and
particularly an annealing status 2195 aluminum alloy tailor-welded
plate with the thickness of 2 mm. Parameters for friction stir
welding are as follows: the welding advancing speed is 200 mm/min
and the welding rotating speed is 1000 rpm; the size of a
rectangular slab is 1200 mm (L).times.600 mm (W); three weld joints
are respectively located at a center of a symmetric axis in the
width direction of the blank, and at two sides, 200 mm far away
from the symmetric axis; and a rigid tool with the length, width
and height of 1200 mm, 300 mm and 300 mm respectively is adopted,
and includes a punch 33, a die 31 and a blank holder 32, wherein
cooling chambers 34 are preset in the die 31. The further specific
steps for example 5 are as follows: [0063] step 1, placing the 2195
aluminum alloy tailor-welded plate 4 onto the tool and allowing
weld zones 42 to be located above the cooling chambers 3-4 of the
die; [0064] step 2, filling the cooling chambers 34 of the die with
the cryogenic fluid medium so that the temperatures of the cooling
chambers 34 of the die drop to -196 degrees Celsius; [0065] step 3,
assembling the blank holder 32 and the punch 33, allowing the blank
holder 32 to apply pressure of 3 MPa, regulating the flow of the
cryogenic fluid medium through the first control valve 11 and the
second control valve 12, and allowing the punch 33 to descend to
apply drawing force to deform the 2195 aluminum alloy tailor-welded
plate 4 when the temperatures of the weld zones 42 of the 2195
aluminum alloy tailor-welded plate 4 reach -196 degrees Celsius and
the temperature of the base metal zone 41 is higher than -150
degrees Celsius, thereby forming an -shaped component with 2195
aluminum alloy tailor-welded plate; and [0066] step 4, separating
the punch 33, the blank holder 32 and the die 31, and taking out
the -shaped component, thereby completing frozen forming of the
-shaped component 7. The cryogenic fluid medium is a very low
temperature cooling medium, and is either liquid nitrogen or liquid
helium.
[0067] By utilizing the feature that the plasticity and the
strength of the weld zone are higher than the plasticity and the
strength of the base metal zone caused by temperature difference on
aluminum alloy tailor-welded plate at a very low temperature, the
cracking problem caused by high degrees of deformation in the weld
zones can be avoided and restore to original microstructure status
after being formed. The -shaped component formed using aluminum
alloy tailor-welded plate in the example can avoid microstructure
damage, the microstructure and mechanical property are basically
not changed by the forming at the very low temperature. In the
example of the frozen forming process of -shaped component with the
aluminum alloy tailor-welded plate, frozen lubricating layers are
formed at working surfaces between the tailor-welded plate and the
tool, which can reduce frictional resistance during flowing of the
blank, reduce forming force, and greatly reduce the tonnage and
cost of forming equipment.
EXAMPLE 6
[0068] This example provides a frozen forming method for a
flat-bottom cylindrical component with aluminum alloy FSW
tailor-welded plate, and differs from Example 1 in that the
aluminum alloy plate is an Al--Zn--Mg--Cu alloy, and particularly
an aging status 7075 aluminum alloy tailor-welded plate with the
thickness of 6.5 mm. Parameters for friction stir welding are as
follows: the welding advancing speed is 300 mm/min and the welding
rotating speed is 800 rpm; and the diameter of a circular blank is
2700 mm and one weld joint is located at a symmetric axis of the
blank; and a flat-bottom cylindrical rigid tool with the diameter
of 2250 mm is adopted, and includes a punch 33, a die 31 and a
blank holder 32, wherein a cooling chamber 34 is preset in the die
31. The further specific steps are as follows: [0069] step 1,
placing the 7075 aluminum alloy tailor-welded plate 4 onto the tool
and allowing a weld zone 42 to be located above the cooling chamber
34 of the die; [0070] step 2, filling the cooling chamber 34 of the
die with the cryogenic fluid medium so that the temperature of the
cooling chamber 34 of the die drops to -180 degrees Celsius; [0071]
step 3, assembling the blank holder 32 and the punch 33, allowing
the blank holder 32 to apply pressure of 3 MPa, regulating the flow
of the cryogenic fluid medium through the first control valve 11
and the second control valve 12, and allowing the punch 33 to
descend to apply drawing force to deform the 7075 aluminum alloy
tailor-welded plate 4 when the temperature of the weld zone 42 of
the 7075 aluminum alloy tailor-welded plate 4 reaches -180 degrees
Celsius and the temperature of the base metal zone 41 is higher
than -150 degrees Celsius, thereby forming a 7075 aluminum alloy
tailor-welded plate flat-bottom cylindrical component; and [0072]
step 4, separating the punch 33, the blank holder 32 and the die
31, and taking out the 7075 aluminum alloy tailor-welded plate
flat-bottom cylindrical component, thereby completing frozen
forming of the 7075 aluminum alloy tailor-welded plate flat-bottom
cylindrical component 7. The cryogenic fluid medium is a very low
temperature cooling medium, and is either liquid nitrogen or liquid
helium.
[0073] By utilizing the feature that the plasticity and the
strength of the weld zone are higher than the plasticity and the
strength of the base metal zone caused by temperature difference on
aluminum alloy tailor-welded plate at a very low temperature, the
cracking problem caused by a high degree of deformation in the weld
zone can be avoided and restore to original microstructure status
after being formed. The -shaped component formed using the aluminum
alloy tailor-welded plate in the example can avoid microstructure
damage, the microstructure and mechanical property are basically
not changed by the forming at the very low temperature. In this
example the frozen forming process of -shaped component with the
aluminum alloy tailor-welded plate, frozen lubricating layers are
formed at working surfaces between the tailor-welded plate and the
tool, which can reduce friction force during flowing of the blank,
reduce forming force, and greatly reduce the tonnage and cost of
forming equipment.
[0074] In the above examples, the fabricated different shaped
component structures or components can be classified as being of
thin wall and large size based on the specific thickness and
diameter values, respectively.
[0075] Although the invention is described in detail in combination
with the above examples, those of ordinary skill in the art shall
understood that they can modify technical schemes documented in the
above examples or perform equivalent replacement on some technical
features, and any modification, equivalent replacement, improvement
and the like made within the spirit and rule of the invention shall
be incorporated in the protection scope of the invention.
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