Technical field
[0001] The present invention relates to an aluminium alloy, which is useful for printing
plate making, especially for (computer) direct-to-plate. The invention also relates
to an article produced from the alloy, which article is, e.g., in the form of sheet,
strip or foil, and to a process of producing same.
Background
[0002] Document
JP2008063667 discloses an aluminium alloy material for lithography. Document
CN101182611A discloses an alloy composition for lithographic sheets. In the recent years, as the
development of the printing technology, the printing plate is changing from presensitized
plate (PS plate) to computer-to-plate (CTP plate). Meanwhile, the printing requires
stringently on the plate, where the CTP technology requires particularly stringently
on the CTP plate and the properties of the aluminium alloy sheet, strip or foil to
produce the CTP plate, such as the appearance properties, physical properties and
adaptability to electrolysis. In particular, the current CTP plates are generally
used for high grade of color printing plate-making. In order to ensure the plate quality,
the properties of the plate substrate are the foundation. The printing field generally
requires the follows:
1) requirements on dimensions of the aluminium alloy sheet/strip/foil;
[0003]
- a) thickness and tolerance
The aluminium alloy sheet/strip/foil useful for CTP plate requires a thickness of
0.14mm-0.50mm, and a tolerance of ±0.005mm;
- b) tolerance of width
The aluminium alloy sheet/strip/foil requires a tolerance of width of ≤±0.5mm; and
- c) uniformity in the longitudinal and transversal directions
The aluminium alloy sheet/strip/foil requires tolerances of thickness in both longitudinal
and transverse directions of ≤±0.005mm. The current plate-making machine sets generally
a thickness of 0.280mm or 0.275mm for the plate, then the variation in the longitudinal
or transverse direction will affect adversely to the plate-making. Also, the settings
of the CTP plate-making device are usually unallowable for adjustment arbitrarily.
2) requirements on appearance of the aluminium alloy sheet/strip/foil
[0004] The appearance of the aluminium alloy sheet/strip/foil is required to be clean and
smooth; have no defects of crack, corrosion hole, corrosion spot, through hole, scratch,
fold, impression, peeling, pine pattern mark or oil mark; have no press-in mark by
a non-metal, sticking mark, peeling or wave on the surface; have no chromatic aberration
or highlighting band; and have no swelling or wavy edges.
3) requirements on the mechanical properties of the aluminium alloy sheet/strip/foil
[0005]
- a) the aluminium sheet for the CTP plate must have good mechanical properties and
good properties after baking.
- b) the CTP plate usually uses an automatic plate loading and an automatic positioning
and punching device, requiring the plate with a stiffness. If the plate is too soft,
the stiffness is lower, and the plate is readily bent to affect adversely the going
up of edition material. If the aluminium sheet is too hard, it is difficult to level
the plate.
4) requirements on the electrolytic properties of the aluminium alloy sheet/strip/foil
[0006] As the CTP plate is usually used for high grade color printing, the grain of the
substrate of the CTP plate is lower than that of the PS plate. In particular, the
CTP plate-making device generally uses a FM screening or FM/AM mixed screening, such
that the reduction of fine screen dot and screen line is associated directly with
the surface roughness of the substrate, i.e., the grain of the substrate. The greater
the grain is, the worse the reduction of the screen dot and screen line is. In order
to obtain a layer with fine and uniform grain through electrolysis, the appearance
quality and the surface roughness of the substrate should be focused. If the appearance
quality of the substrate is too bad, the defects of the plate surface cannot be eliminated
without a strengthened electrolysis, resulting in a greater grain. If the substrate
has a Ra≥0.30µm, it is difficult to obtain a lower grain.
[0007] In order to obtain a layer with fine and uniform grain, the inherent composition
of the aluminium substrate is the core. That is, the components of the aluminium alloy
to produce the aluminium plate are interested, which, in turn, are associated with
the composition and contents of the specific metals of the aluminium alloy. The process
of preparing or treating the aluminium alloy is also concerned.
[0008] A good aluminium alloy sheet/strip/foil requires not only good mechanical properties
but also good adaptability to electrolysis, so as to be useful for electrolysis with
hydrochloric acid or nitric acid electrolyte. A sensitivity of grain corresponding
to the electrolysis is also required, so as to form a layer with fine and uniform
grain without a strengthened treatment.
5) requirements on the planeness of the aluminium alloy sheet/strip/foil
[0009] The aluminium alloy sheet/strip/foil for the CTP requires a high planeness, as most
of the CTP apparatuses use scanning imaging, different from the printing-down for
the PS plate where a vacuum is applied to tight the plate with the film. Then, if
the plate has a poor planeness, the quality of the imaging by laser will be affected
adversely. Therefore, the aluminium alloy sheet/strip/foil for CTP requires stringently
on the planeness.
[0010] For the production of an aluminium alloy sheet/strip/foil, some factors are generally
controlled, comprising:
- 1. Controlling the contents of the trace elements, so as to improve the mechanical
properties and the grain properties by electrolysis;
- 2. Using a homogenous annealing at a high temperature, so as to improve the internal
structure of the product; and
- 3. Using appropriate intermediate annealing temperature and period for cold rolling,
for the desired mechanical properties of the product.
[0011] Currently, in the market of aluminium alloy sheet/strip/foil for CTP print, the AA1050
alloy is popularly used. For the AA1050 alloy, those skilled persons can refer to
"
Quality Requirements and Typical Defects Analysis of Aluminium Material for CTP",
Aluminium Fabrication, 2008.3, Vol. 182, such as the aluminium substrate introduced. The quality of electrochemical roughening
is affected by a plurality of factors, such as the electric current density, the linear
velocity, the chemical components and the like. In order to obtain a better roughened
surface, an AA1050 alloy is generally used, where the content of aluminium is controlled
to be 99.5% or more.
[0012] For the currently usual AA1050 alloy, the components of the alloy are controlled
as follows:
Si (Max) |
0.25 |
Fe (Max) |
0.4 |
Cu (Max) |
0.05 |
Mn (Max) |
0.05 |
Mg (Max) |
0.05 |
Zn (Max) |
0.05 |
V (Max) |
0.05 |
Ti (Max) |
0.03 |
Other Each (Max) |
0.03 |
Others Total |
-- |
Al(Min) |
99.50 |
[0014] The CTP substrate prepared according to the Table above comprises the typical mechanical
properties of: a tensile strength of 130-150MPa, a yield strength of 120-140MPa, and
an elongation of 1.0-3.0%, at room temperature; and a tensile strength of 120-130MPa,
a yield strength of 110-120MPa, and an elongation of 2.0-3.5%, at a baking temperature.
It can be seen that the properties are not so stable, decreasing the printing quality.
[0015] As the CTP plate is usually used for high grade color printing, the grain of the
substrate of the CTP plate is lower than that of the PS plate. In particular, the
CTP plate-making device generally uses a FM screening or FM/AM mixed screening, such
that the reduction of fine screen dot and screen line is associated directly with
the surface roughness of the substrate, i.e., the grain of the substrate. The greater
the grain is, the worse the reduction of the screen dot and screen line is. The AA1050
alloy has poor uniformity for the internal structure, such that the electrolysis properties
are undesirable, and the grains after electrolytic roughening are not uniform, resulting
too poor reduction to satisfy the requirement by the high grade of CTP plate.
Summary of the Invention
[0016] Regarding the problems of the prior art above, it is one of the objects of the present
invention to provide a process of producing aluminium sheet/strip/foil for printing
plate. The aluminium sheet/strip/foil has a uniform internal structure, such that
besides the high surface quality and good planeness of the plate, the sheet/strip/foil
has improved mechanical properties at room temperature and improved mechanical properties
at a baking temperature, and also can generate an excellent grain structure through
electrolysis.
[0017] Accordingly, the present invention provides an aluminium alloy for printing plate,
comprising Al, Si, Fe, Mg, Cu, Ti and other impurities, characterized in that the
components are comprised in amounts by weight defined by claim 1. Mg/Fe>=0.125.
[0018] The present invention also provides a process of producing an aluminium alloy article
for printing plate, characterized in comprising the steps of:
- 1) adding raw materials of the alloy into a remelting furnace, melting, refining,
inclusion removing, degassing and filtering, followed by casting into a sheet ingot
with a thickness of about 500 to about 650 mm;
- 2) sawing the head and butt of the sheet ingot, scalping, and then heating to a temperature
of about 500 to about 600 degrees centigrade for about 2 to about 12 hours; and hot
rolling the sheet ingot into a strip with a thickness of about 2.0 to about 5.0 mm
at a finish rolling temperature of about 250 to about 320 degrees centigrade;
- 3) cold rolling the strip to a thickness of about 1 to about 3 mm, wherein the roll
has a roughness, Ra, of about 0.30 to about 0.80 µm;
- 4) annealing the cold rolled strip from step 3) in an annealing furnace at a temperature
of about 350 to about 450 degrees centigrade, and holding the temperature for about
2 to about 4 hours;
- 5) continuing rolling the strip from step 4) on a cold rolling machine to a thickness
of about 0.14 to about 0.4 mm, with a Ra of about 0.15 to about 0.30 µm; and
- 6) cleaning the strip from step 5), edge trimming, and tension leveling, to obtain
the aluminium alloy article for printing plate according to the present invention,
which is in the form of, e.g., strip, foil or sheet.
[0019] Accordingly, the present invention also provides an aluminium alloy sheet/strip/foil
for printing plate produced by the process above, which sheet/strip/foil comprises
the aluminium alloy according to the present invention.
[0020] The aluminium alloy sheet/strip/foil has a thickness of about 0.14 mm to about 0.50
mm, preferably 0.20 to 0.38 mm, such as about 0.220 mm to about 0.275 mm.
[0021] The aluminium alloy article (such as an aluminium alloy strip) according to the present
invention has a tensile strength of about 175 to about 210MPa, a yield strength of
about 170 to about 200MPa, and/or an elongation of about 2% to about 6%, at room temperature.
[0022] Through a simulated baking condition treatment at a temperature of 240 degrees centigrade
for 10 minutes, the aluminium alloy article, after cooling, has a tensile strength
of about 145 to about 170MPa, a yield strength of about 135 to about 155MPa, and/or
an elongation of about 3% to about 8%.
Description of Drawings
[0023]
Fig.1: comparison of crystal grains in the as-cast state and grains after annealing
between the alloy strip produced by Example 1 according to the present invention and
an alloy sheet produced by AA1050 alloy from prior art.
Fig.2: comparison of grain precipitation of the intermetallic compounds (the second
phase) between the alloy strip produced by Example 1 according to the present invention
and an alloy sheet produced by AA1050 alloy from prior art.
Fig.3: comparison of grains between the alloy strip produced by Example 1 according
to the present invention and an alloy sheet produced by AA1050 alloy from prior art.
Fig.4: comparison of article etching between the alloy strip produced by Example 1
according to the present invention and an alloy sheet produced by AA1050 alloy from
prior art.
Fig.5: comparison of images after graining between the alloy strip produced by Examples
1 to 5 according to the present invention and an alloy sheet produced by AA1050 alloy
from prior art; under the test conditions of SEM×250, and a line speed of 50m/min,
60m/min, 70m/min, and 80m/min, respectively.
Fig.6: comparison of images after graining between the alloy strip produced by Examples
1 to 5 according to the present invention and an alloy sheet produced by AA1050 alloy
from prior art; under the test conditions of SEM×1000, and a line speed of 50m/min,
60m/min, 70m/min, and 80m/min, respectively.
Fig.7: comparison of etching in the graining electrolytes between the alloy strip
produced by Examples 1 to 5 according to the present invention and an alloy sheet
produced by AA1050 alloy from prior art; under the test conditions of: etching after
5 seconds of deoiling, SEM×40 magnifications.
Fig.8: comparison of corrosion etching in the graining electrolytes between the alloy
strip produced by Examples 1 to 5 according to the present invention and an alloy
sheet produced by AA1050 alloy from prior art; under the test conditions of: etching
after 5 seconds of deoiling, SEM×250 magnifications.
Embodiments of the invention
[0024] The present invention provides an aluminium alloy for printing plate, comprising
Al, Si, Fe, Mg, Cu, Ti and other impurities, characterized in that the components
are comprised in amounts by weight as defined in claim 1. Mg/Fe>=0.125.
[0025] In an embodiment, Si is preferably used in an amount of not less than 0.05%, more
preferably not less than 0.06%. In an embodiment, Si is preferably used in an amount
of not more than 0.10%, more preferably not more than 0.08%.
[0026] Fe is used in an amount of not less than 0.3%. In an Fe is used in an amount of not
more than 0.38%.
[0027] Mg is used in an amount of not less than 0.07%. Mg is used in an amount of not more
than 0.10%.
[0028] In an embodiment, Cu is preferably used in an amount of not less than 0.0045%, more
preferably not less than 0.005%. In an embodiment, Cu is preferably used in an amount
of not more than 0.009%, more preferably not more than 0.008%.
[0029] In an embodiment, Ti is preferably used in an amount of not less than 0.004%, more
preferably not less than 0.005%. In an embodiment, Ti is preferably used in an amount
of not more than 0.017%, more preferably not more than 0.015%.
[0030] The aluminium alloy according to the present invention may comprise the typical impurities
in the art, such as Li, Na, Pb, Be, Zn, or V, where the amount of any one impurity
is in an amount by weight of not more than 0.03%. Preferably, the total amount of
the impurities is at most 0.1 wt%. The aluminium alloy according to the present invention
comprises Al in an amount of not less than 99.30%.
[0031] The aluminium alloy according to the present invention can be produced by a process
known in the art, according to the formulation above. A typical producing process
comprises, for example:
- 1) melt casting - scalping - annealing - hot rolling - cold rolling - annealing -
cold rolling - tension leveling - packaging; or
- 2) cast rolling - cold rolling - tension leveling - packaging.
[0032] The aluminium alloy sheet/strip/foil according to the present invention can be used
for CTP printing plate, bottle cap, sheet for soft tube, curtain wall panel, decoration
board, case of an electric equipment, heat exchanger, wrapper of electric cable, extrusion
coil, powder for fireworks, nameplate, light-reflecting device, thermal isolation
aluminium foil and so on.
[0033] The aluminium alloy according to the present invention can be particularly used to
produce an aluminium alloy sheet/strip/foil for printing plate (including a treatment-free
printing plate). Accordingly, the present invention also provides a process of producing
an aluminium alloy sheet/strip/foil for printing plate, characterized in comprising
the steps of:
- 1)adding raw materials of the alloy into a remelting furnace, melting, holding, refining
, degassing and filtering, followed by casting into a sheet ingot with a thickness
of about 500 to about 650 mm;
- 2)sawing the head and butt of the sheet ingot, scalping, and then heating to a temperature
of about 500 to about 600 degrees centigrade for about 2 to about 12 hours; and hot
rolling the sheet ingot into a strip with a thickness of about 2.0 to about 5.0 mm
at a temperature of about 250 to about 320 degrees centigrade;
- 3) cold rolling the strip obtained in step 2) to a thickness of about 1 to about 3
mm, wherein the roll has a roughness, Ra, of about 0.30 to about 0.80 µm;
- 4) annealing the cold rolled strip from step 3) in an annealing furnace at a temperature
of about 350 to about 450 degrees centigrade for an intermediate annealing, and holding
the temperature for about 2 to about 4 hours;
- 5) continuing rolling the strip from step 4) on a cold roller to a thickness of about
0.14 to about 0.50 mm, to provide a sheet, strip or foil with a Ra of about 0.15 to
about 0.30 µm; and
- 6) cleaning the sheet, strip or foil from step 5), edge trimming, and tension leveling,
to obtain the aluminium alloy sheet /strip/ foil for printing plate according to the
present invention.
[0034] In an embodiment, the remelting furnace has a temperature of about 720 to 740 degrees
centigrade. The sheet ingot has preferably a thickness of not less than about 520mm.
The sheet ingot has preferably a thickness of not more than about 620mm.
[0035] Accordingly, the present invention also provides an aluminium alloy article produced
by the process above for printing plate, such as in the form of sheet/strip/foil,
which comprises the aluminium alloy according to the present invention.
[0036] In an embodiment, the alloy strip has a thickness of about 0.27mm.
[0037] In an embodiment, the aluminium alloy strip has a tensile strength at room temperature
of about 175 to about 210MPa, preferably about 185MPa. In an embodiment, the aluminium
alloy strip has a yield strength at room temperature of about 170 to about 200MPa,
preferably about 180MPa. In an embodiment, the aluminium alloy strip has an elongation
at room temperature of about 2 to about 6%, preferably about 2 to about 3.5%.
[0038] In an embodiment, through a simulated baking condition treatment at a temperature
of 240 degrees centigrade for 10 minutes, the aluminium alloy strip, after cooling,
has a tensile strength of about 145 to about 175 MPa, preferably about 160 to about
175 MPa or about 160 to about 170 MPa; a yield strength of about 135 to about 155
MPa, preferably about 140 to about 150 MPa; and/or an elongation of about 3 to about
8%, preferably about 3 to about 6%.
[0039] The technical solution of the present invention can achieve beneficial technical
effects, including, but not limited to, for example, the present invention capable
of using a relatively lower homogenizing temperature to achieve a complete transition
between a non-equilibrium phase and a equilibrium phase, which increases the utilization
efficiency of heating furnace and saves the energy consumption; according to the present
invention, homogeneously dispersed intermetallic compounds being precipitated, such
that the electrolytic roughening occurs at more positions homogeneously and rapidly,
the electrolyzing voltage is decreased and the electrolysis energy consumption is
saved; the technical solution according to the present invention resulting in a clean
surface, which can improve greatly the treatment efficiency before electrolysis and
save the consumption of acid and base; and the technical solution according to the
present invention resulting in high mechanical properties, such that a rapid plate
loading can be achieved, the production efficiency can be increased, and the excellent
baking performances improves greatly the durability.
Examples
[0040] The present invention will be illustrated through the following examples, which are
exemplary but not restrictive.
Material :
[0041] Electrolytic aluminium ingot Al99.70, available from Aluminium Corporation of China
Limited.
[0042] AMG grain refiner, available from London and Scandinavian metallurgical Co., Ltd.
Company.
[0043] Intermediate alloy, 80Fe, 20Si, 50Cu, Ti5, available from Yongte Master Alloys Co.,
Ltd., Jiangxi.
Instruments and testing methods:
[0044] Hydrogen gauge: HMA0100D, available from ABB, used to measure the hydrogen content
of the melt.
[0045] Inclusion measuring instrument: PZM0700D, available from ABB, used to measure the
slag content of the melt.
[0046] Scanning electron microscope: EVO18, available from Zeiss, Germany, with a test method
of secondary electron, backscattering.
[0047] Microscope: Zeiss Imager.A2m, available from Zeiss, Germany, with a test method of
light field, polarized light.
[0048] Roughometer: Hommel Tester W55, available from Hommel, Germany, used for the roughness
and Burr measurement.
[0049] Micrometer: Mitutoyo, available from Japan, used for thickness measurement.
[0050] Tensile testing machine: CMT6203/6503 electronic universal tensile testing machine,
available from MTS, USA, referring to "
GB 228 - 2002 Standard Test Method for tensile testing of metallic materials at room temperature".
Example 1
[0051] An aluminium alloy strip according to the present invention was produced according
to the process illustrated below, referring to the example formulation as shown in
Table 1:
- (1) providing materials of: 108000kg of 99.7 aluminium ingot (containing 40kg of Si,
194kg of Fe, 1.1kg of Mg, 0.5kg of Cu), 15kg of AlSi20 alloy, 230kg of 80Fe agent,
63.5kg of Mg ingot, and 7.6kg of AlCu50 alloy; adding into a remelting furnace having
a remelting temperature of 750 degrees centigrade, refining, inclusion removing, stirring,
and analyzing and regulating the components, the composition listed in Table 1,adding
into a stewing furnace, stewing, refining, degassing, inclusion removing, adding Al-5Ti-1B
rods (1.2 - 1.4kg/t molten aluminium) and casting into a cast ingot in a casting machine
at a casting temperature of 705 degrees centigrade;
- (2) controlling the holding temperature for hot rolling at 580 degrees centigrade,
for holding the metal for 2 hours;
- (3) hot rolling with an initial rolling temperature of 520 degrees centigrade and
a finish rolling temperature of 320 degrees centigrade, to obtain a finishing rolled
blank with a thickness of 4.2mm;
- (4)subjecting the hot rolled blank to a secondary rolling to a intermediate thickness
of 2.0mm;
- (5) interannealing the 2.0mm blank at a temperature of 450 degrees centigrade, with
holding the metal for 2 hours; and
- (6) subjecting the blank to three times of further rolling to an article thickness
of 0.27mm.
Example 2
[0052] An aluminium alloy strip according to the present invention was produced according
to the process illustrated below, referring to the example formulation as shown in
Table 1:
- (1) providing materials of: 104000kg of 99.7 aluminium ingot (containing 52kg of Si,
198kg of Fe, 1.5kg of Mg), 156kg of AlSi20 alloy, 220kg of 80Fe agent, 102kg of Mg
ingot, and 8.3kg of AlCu50 alloy; adding into a remelting furnace having a remelting
temperature of 750 degrees centigrade, refining, inclusion removing, stirring, and
analyzing and regulating the components, the composition listed in Table 1,adding
into a stewing furnace, stewing, refining, degassing, inclusion removing, adding Al-5Ti-1B
wires (1.2 ∼ 1.4kg/t molten aluminium) and casting into a cast ingot in a casting
machine at a casting temperature of 705 degrees centigrade;
- (2) controlling the holding temperature for hot rolling at 550 degrees centigrade,
for holding the metal for 2 hours;
- (3) hot rolling with an initial rolling temperature of 500 degrees centigrade and
a finish rolling temperature of 320 degrees centigrade, to obtain a finishing rolled
blank with a thickness of 4.2mm;
- (4) subjecting the hot rolled blank to a further rolling to an intermediate thickness
of 2.0mm;
- (5) interannealing the 2.0mm blank at a temperature of 420 degrees centigrade, with
holding the metal for 2 hours; and
- (6) subjecting the blank to three times of further rolling to an article thickness
of 0.27mm.
Example 3
[0053] An aluminium alloy strip according to the present invention was produced according
to the process illustrated below, referring to the example formulation as shown in
Table 1:
- (1) providing materials of: 116000kg of 99.7 aluminium ingot (containing 58kg of Si,
224kg of Fe, 1.2kg of Mg, 1.6kg of Cu), 116kg of AlSi20 alloy, 184kg of 80Fe agent,
91.6kg of Mg ingot, and 15.3kg of AlCu50 alloy; adding into a remelting furnace having
a remelting temperature of 770 degrees centigrade, refining, inclusion removing, stirring,
and analyzing and regulating the components, the composition listed in Table 1,adding
into a stewing furnace, stewing, refining, degassing, inclusion removing, adding Al-5Ti-1B
wires (1.2 ∼ 1.4kg/t molten aluminium) and casting into a cast ingot in a casting
machine at a casting temperature of 720 degrees centigrade;
- (2) controlling the holding temperature for hot rolling at 520 degrees centigrade,
for holding the metal for 4 hours;
- (3) hot rolling with an initial rolling temperature of 480 degrees centigrade and
a finish rolling temperature of 320 degrees centigrade, to obtain a finishing rolled
blank with a thickness of 4.5mm;
- (4)subjecting the hot rolled blank to a further rolling to a intermediate thickness
of 2.2mm;
- (5) interannealing the 2.2mm blank at a temperature of 390 degrees centigrade, with
holding the metal for 4 hours; and
- (6) subjecting the blank to three times of further rolling to an article thickness
of 0.27mm.
Example 4
[0054] An aluminium alloy strip according to the present invention was produced according
to the process illustrated below, referring to the example formulation as shown in
Table 1:
- (1) providing materials of: 110000kg of 99.7 aluminium ingot (containing 53kg of Si,
208kg of Fe, 0.7kg of Mg, 0.6kg of Cu), 175kg of AlSi20 alloy, 235kg of 80Fe agent,
98kg of Mg ingot, and 20.5kg of AlCu50 alloy; adding into a remelting furnace having
a remelting temperature of 770 degrees centigrade, refining, inclusion removing, stirring,
and analyzing and regulating the components, the composition listed in Table 1,adding
into a stewing furnace, stewing, refining, degassing, inclusion removing, adding Al-5Ti-1B
wires (1.2 ∼ 1.4kg/t molten aluminium) and casting into a cast ingot in a casting
machine at a casting temperature of 720 degrees centigrade;
- (2) controlling the holding temperature for hot rolling at 520 degrees centigrade,
for holding the metal for 6 hours;
- (3) hot rolling with an initial rolling temperature of 480 degrees centigrade and
a finish rolling temperature of 320 degrees centigrade, to obtain a finishing rolled
blank with a thickness of 4.5mm;
- (4)subjecting the hot rolled blank to a further rolling to a intermediate thickness
of 2.2mm;
- (5) interannealing the 2.2mm blank at a temperature of 360 degrees centigrade, with
holding the metal for 6 hours; and
- (6) subjecting the blank to three times of further rolling to an article thickness
of 0.27mm.
Example 5
[0055] An aluminium alloy strip according to the present invention was produced according
to the process illustrated below, referring to the example formulation as shown in
Table 1:
- (1) providing materials of: 108000kg of 99.7 aluminium ingot (containing 42kg of Si,
198kg of Fe, 1.7kg of Mg, 0.6kg of Cu), 276kg of AlSi20 alloy, 238kg of 80Fe agent,
127kg of Mg ingot, 18.2kg of AlCu50 alloy, and 73kg of AlTi20 alloy; adding into a
remelting furnace having a remelting temperature of 770 degrees centigrade, refining,
inclusion removing, stirring, and analyzing and regulating the components, the composition
listed in Table 1,adding into a stewing furnace, stewing, refining, degassing, inclusion
removing, adding Al-5Ti-1B wires (1.2 ∼ 1.4kg/t molten aluminium) and casting into
a cast ingot in a casting machine at a casting temperature of 720 degrees centigrade;
- (2) controlling the holding temperature for hot rolling at 520 degrees centigrade,
for holding the metal for 8 hours;
- (3) hot rolling with an initial rolling temperature of 480 degrees centigrade and
a finish rolling temperature of 320 degrees centigrade, to obtain a finishing rolled
blank with a thickness of 4.5mm;
- (4)subjecting the hot rolled blank to a further rolling to a intermediate thickness
of 2.5mm;
- (5) interannealing the 2.5mm blank at a temperature of 380 degrees centigrade, with
holding the metal for 8 hours; and
- (6) subjecting the blank to three times of further rolling to an article thickness
of 0.27mm.
Table 1:
Ex. |
Si |
Fe |
Mg |
Ti |
Cu |
Any one of the other impurities |
Al |
1 |
0.04 |
0.35 |
0.06 |
0.015 |
0.004 |
<0.03 |
balance |
2 |
0.08 |
0.36 |
0.10 |
0.015 |
0.004 |
<0.03 |
balance |
3 |
0.07 |
0.32 |
0.08 |
0.015 |
0.008 |
<0.03 |
balance |
4 |
0.08 |
0.36 |
0.09 |
0.012 |
0.01 |
<0.03 |
balance |
5 |
0.09 |
0.36 |
0.12 |
0.020 |
0.009 |
<0.03 |
balance |
Example 6
[0056] The aluminium strips obtained from examples 1 to 5 were analyzed for the grained
texture (analysis of roughness). The product of the invention was tailed to 500mm×
the width of the aluminium web, and measured for the roughness in an direction perpendicular
to the rolling direction using the Hommel Tester W55 roughometer, and calculated the
average value of a plurality of measured values.
[0057] With testing experiments, the products according to the present invention showed
results as listed in Table 2 below:
Table 2:
Sample |
Ra (um) |
Rz (um) |
Rsk |
Rku |
Rpk (um) |
Rk (um) |
Rvk (um) |
1050 |
0.23 |
2.21 |
0.60 |
3.40 |
0.39 |
0.70 |
-0.18 |
Ex.1 |
0.19 |
1.51 |
0.45 |
3.01 |
0.33 |
0.64 |
-0.17 |
Ex.2 |
0.19 |
1.24 |
0.57 |
3.05 |
0.38 |
0.68 |
-0.18 |
Ex.3 |
0.20 |
1.60 |
0.55 |
2.98 |
0.34 |
0.62 |
-0.15 |
Ex.4 |
0.17 |
1.35 |
0.49 |
3.12 |
0.34 |
0.69 |
-0.17 |
Ex.5 |
0.18 |
1.58 |
0.60 |
2.99 |
0.37 |
0.69 |
-0.16 |
Example 7:
[0058] The aluminium alloy strips obtained from examples 1-5 were compared with the control
alloy strip prepared from the 1050 alloy from prior art for the grained images, using
SEM and interferometer.
[0059] The test conditions comprised: electrolytically graining the product obtained according
to the present invention and the 1050 alloy from prior art with various electrolytic
parameters, simulating line speeds of 50m/min, 60m/min, 70m/min, and 80m/min, respectively,
to provide various surfaces with different grains, where the experimental results
at SEM
∗ 250 were showed in Fig.5. Another test condition comprised: providing electrolytically
grained surfaces with the same process above, except for SEM
∗ 1000, where the experimental result were showed in Fig.6.
[0060] It can be seen clearly that under the test conditions simulating line speeds of 50
and 60m/minute, the strip according to the present invention had less flattops, deeper
extent of graining, and more structure details, compared with the control 1050 alloy.
[0061] The MPA and MPD results from analyzing the grained images were summarized in Table
3 below:
Table 3
Sample |
Testing condition |
Graining area (um2) |
Graining depth (um) |
Median |
Standard Deviation |
Median |
Standard Deviation |
1050 |
50m/min |
26.6 |
41.2 |
1.87 |
0.52 |
Ex.1 |
24.2 |
37.7 |
1.88 |
0.45 |
Ex.2 |
25.5 |
39.3 |
1.67 |
0.49 |
Ex.3 |
25.0 |
39.6 |
1.72 |
0.48 |
Ex.4 |
26.1 |
40.6 |
1.77 |
0.43 |
Ex.5 |
24.8 |
36.2 |
1.83 |
0.47 |
1050 |
60m/min |
22.1 |
46.0 |
2.08 |
0.42 |
Ex.1 |
20.2 |
32.9 |
1.94 |
0.37 |
Ex.2 |
23.2 |
36.4 |
1.95 |
0.44 |
Ex.3 |
20.9 |
35.5 |
1.94 |
0.43 |
Ex.4 |
20.4 |
35.9 |
1.72 |
0.48 |
Ex.5 |
21.3 |
37.2 |
1.78 |
0.45 |
1050 |
70m/min |
33.9 |
59.8 |
2.50 |
0.59 |
Ex.1 |
28.3 |
51.5 |
2.17 |
0.49 |
Ex.2 |
27.3 |
50.3 |
2.02 |
0.45 |
Ex.3 |
27.5 |
46.9 |
2.06 |
0.45 |
Ex.4 |
26.8 |
47.4 |
1.97 |
0.42 |
Ex.5 |
28.1 |
48.6 |
2.10 |
0.46 |
1050 |
80m/min |
52.5 |
70.1 |
3.06 |
0.82 |
Ex.1 |
45.4 |
63.6 |
2.41 |
0.73 |
Ex.2 |
44.3 |
60.7 |
2.66 |
0.77 |
Ex.3 |
43.9 |
61.4 |
2.52 |
0.74 |
Ex.4 |
43.6 |
61.8 |
2.73 |
0.71 |
Ex.5 |
44.4 |
62.6 |
2.67 |
0.75 |
Example 8:
[0062] The aluminium alloy strips obtained from examples 1-5 were compared with the control
alloy strip prepared from the 1050 alloy from prior art for etching in electrolyte,
using SEM and interferometer. The product obtained according to the present invention
and the 1050 alloy from prior art were immersed into a 34g/L NaOH solution, washed
with tap water and added with 15g/l (HCl) + 15g/l (SO42-) solution for etching.
[0063] The test condition comprised: corrosion etching after 5 seconds of deoiling treatment,
SEM
∗ 40, experimental result being showed in Fig.7. Another test condition comprised:
corrosion etching after 5 seconds of deoiling treatment, SEM
∗ 250: experimental results being showed in Fig.8.
[0064] The images at different magnifications in Figs.7 and 8 showed, the product obtained
according to the present invention had less etched points and relatively lighter etched
channels on the surface, compared with the 1050 alloy from prior art.
Example 9:
[0065] The aluminium alloy strips obtained from examples 1-5 were compared with the control
alloy strip prepared from the 1050 alloy from prior art for open circuit potential
(OCP). The product obtained according to the present invention and the 1050 alloy
product were placed in an electrolyte for etching, and measured the open circuit potential
and etching potential difference through the polarization curve.
[0066] The results were showed in Table 4 below:
Table 4
Sample |
OCP |
Median |
AA1050 |
A |
-0.68 |
-0.69 |
B |
-0.70 |
Ex.1 |
A |
-0.67 |
-0.67 |
B |
-0.67 |
Ex.2 |
A |
-0.69 |
-0.68 |
B |
-0.68 |
Ex.3 |
A |
-0.66 |
-0.67 |
B |
-0.68 |
Ex.4 |
A |
-0.65 |
-0.65 |
B |
-0.66 |
Ex.5 |
A |
-0.66 |
-0.66 |
B |
-0.67 |
Example 10:
[0067] The aluminium alloy strips obtained from examples 1-5 were compared with the control
alloy strip prepared from the 1050 alloy from prior art for mechanical properties.
The tensile property and the crack resistance were tested using an electronic universal
tensile testing machine and cold bending test. The unbaked mechanical properties were
tested according to GB/T 228-2002 at room temperature, and the baked properties were
tested according to the GB method after baking the sample at 240 degrees centigrade
∗ 10min and cooling the same; while the cold bending test was carried out according
To GB/T 15825.2-2008 at room temperature.
[0068] The results were showed in Tables 5 and 6 below:
Table 5: tensile properties: baked and unbaked
Sample |
Form |
Length |
Thickness |
Width |
Yield Strength |
Standard Deviation |
Tensile Strength |
Standard Deviation |
Elongation |
Standard Deviation |
mm |
mm |
mm |
MPa |
|
MPa |
|
% |
|
1050 |
Unbaked |
50 |
0.27 |
12.55 |
142 |
3.7 |
165 |
2.0 |
1.7 |
0.23 |
Baked |
50 |
0.27 |
12.54 |
121 |
5.6 |
149 |
1.9 |
2.4 |
0.14 |
Ex.1 |
Unbaked |
50 |
0.27 |
12.53 |
189 |
2.5 |
196 |
1.5 |
4.2 |
0.19 |
Baked |
50 |
0.27 |
12.54 |
168 |
2.2 |
175 |
1.7 |
3.3 |
0.16 |
Ex.2 |
Unbaked |
50 |
0.27 |
12.55 |
186 |
2.5 |
192 |
1.9 |
3.9 |
0.20 |
Baked |
50 |
0.27 |
12.55 |
166 |
2.3 |
172 |
1.8 |
3.0 |
0.19 |
Ex.3 |
Unbaked |
50 |
0.27 |
12.53 |
185 |
2.4 |
190 |
2.1 |
4.5 |
0.19 |
Baked |
50 |
0.27 |
12.55 |
164 |
2.4 |
171 |
2.0 |
3.3 |
0.19 |
Ex.4 |
Unbaked |
50 |
0.27 |
12.54 |
181 |
2.7 |
189 |
1.6 |
4.2 |
0.18 |
Baked |
50 |
0.27 |
12.54 |
160 |
2.6 |
169 |
1.8 |
3.1 |
0.16 |
Ex.5 |
Unbaked |
50 |
0.27 |
12.55 |
182 |
2.6 |
191 |
1.6 |
3.7 |
0.19 |
Baked |
50 |
0.27 |
12.54 |
163 |
2.6 |
170 |
1.7 |
3.2 |
0.18 |
Table 6: crack resistance
Sample |
Testing direction |
Test 1 |
Test 2 |
Test 3 |
Test 4 |
Test 5 |
Cyclic median |
Standard Deviation |
1050 |
longitudinal |
6568 |
6321 |
6111 |
6520 |
5881 |
6063 |
1066 |
transverse |
5124 |
5493 |
5055 |
5556 |
5085 |
5493 |
666 |
Ex.1 |
longitudinal |
8445 |
8252 |
8294 |
8383 |
8409 |
8251 |
600 |
transverse |
7403 |
7411 |
7158 |
7268 |
7352 |
7277 |
388 |
Ex.2 |
longitudinal |
8555 |
8358 |
8299 |
8634 |
8640 |
8379 |
663 |
transverse |
7676 |
7915 |
7842 |
7776 |
7993 |
7705 |
419 |
Ex.3 |
longitudinal |
8561 |
8441 |
8396 |
8787 |
8702 |
8533 |
672 |
transverse |
7468 |
7502 |
7532 |
7661 |
7580 |
7466 |
408 |
Ex.4 |
longitudinal |
8609 |
8477 |
8692 |
8699 |
8543 |
8605 |
647 |
transverse |
7556 |
7638 |
7458 |
7705 |
7691 |
7573 |
442 |
Ex.5 |
longitudinal |
8809 |
8792 |
8715 |
8268 |
8544 |
8641 |
694 |
transverse |
7374 |
7706 |
7519 |
7688 |
7551 |
7536 |
462 |
Example 11:
[0069] The aluminium alloy strips obtained from examples 1-5 were compared with the control
alloy strip prepared from the 1050 alloy from prior art for deoiling ability. A unit
area of the product obtained according to the present invention and that of the 1050
alloy product were weighed, placed into a sodium hydroxide emulsion for etching, taken
out, then rinsed with water, dried and weighed. The weight loss in a unit period was
calculated. The testing conditions comprised: a clean surface of the sample being
required, the etching solution being 34g/l NaOH at 70 degrees centigrade, and etching
period of 5 seconds.
[0070] The results were showed in Table 7 below:
Table 7
Sample |
No. |
Weight before deoiling (g) |
Weight after deoiling (g) |
Δ (g/dm2) |
Δ (g/dm2) |
ΔMedian (g/dm2) |
Standard derivation |
Standard derivation % |
1050 |
1 |
7.3500 |
7.3197 |
0.0151 |
1.51 |
1.48 |
0.05 |
3.1 |
2 |
7.3498 |
7.3208 |
0.0145 |
1.45 |
Ex.1 |
3 |
7.5265 |
7.4935 |
0.0165 |
1.65 |
1.66 |
0.01 |
0.85 |
4 |
7.4998 |
7.4664 |
0.0167 |
1.67 |
Ex.2 |
5 |
7.5502 |
7.5170 |
0.0166 |
1.66 |
1.67 |
0.01 |
0.94 |
6 |
7.5499 |
7.5163 |
0.0168 |
1.68 |
Ex.3 |
7 |
7.5156 |
7.4818 |
0.0169 |
1.69 |
1.67 |
0.03 |
0.99 |
8 |
7.5151 |
7.4823 |
0.0164 |
1.64 |
Ex.4 |
9 |
7.4999 |
7.4665 |
0.0167 |
1.67 |
1.67 |
0.02 |
0.95 |
10 |
7.4998 |
7.4666 |
0.0166 |
1.66 |
Ex.5 |
11 |
7.5067 |
7.4731 |
0.0168 |
1.68 |
1.68 |
0.02 |
0.96 |
12 |
7.5059 |
7.4723 |
0.0168 |
1.68 |
1. An aluminium alloy, comprising Al, Si, Fe, Mg, Cu, Ti and optionally other impurities,
characterized in that the components are comprised in amounts by weight of: Si: 0.04-0.1%, Fe: 0.3-0.38%,
Mg: 0.07-0.10%, Cu: 0.004-0.01%, Ti: 0.003-0.02%; any one of the other impurities
is in an amount by weight of no more than 0.03%; and the balance is Al.
2. The aluminium alloy according to claim 1, characterized in that Mg/Fe>=0.125.
3. The aluminium alloy according to claim 1, characterized in that Cu is comprised in an amount of not less than 0.0045%, preferably not less than 0.005%;
and/or Cu is comprised in an amount of not more than 0.009%, preferably not more than
0.008%.
4. The aluminium alloy according to claim 1, characterized in that Ti is comprised in an amount of not less than 0.004%, preferably not less than 0.005%;
and/or Ti is comprised in an amount of not more than 0.019%, preferably not more than
0.017%.
5. The aluminium alloy according to claim 1, characterized in that the impurities comprise Li, Na, Pb, Be, Zn and/or V.
6. The aluminium alloy according to claim 1, characterized in that the total amount of the impurities is at most 0.1 wt%.
7. The aluminium alloy according to claim 1, characterized in that Al is comprised in an amount of not less than 99.30%.
8. An article comprising the aluminium alloy according to claim 1.
9. The article according to claim 8, characterized in being in the form of strip, foil or sheet.
10. The article according to claim 9, characterized in that the aluminium sheet/strip/foil has a thickness of about 0.14mm to about 0.5mm, preferably
about 0.18mm to about 0.38mm.
11. The article according to claim 8 or 9, characterized in having a tensile strength of about 175 to about 210MPa, a yield strength of about
170 to about 200MPa, and/or an elongation of about 2% to about 6%, at room temperature;
and
in that through a simulated baking condition treatment at a temperature of 240 degrees centigrade
for 10 minutes, the aluminium alloy article, after cooling, has a tensile strength
of about 145 to about 170MPa, a yield strength of about 135 to about 155MPa, and/or
an elongation of about 3% to about 8%.
12. Use of the article according to claim 8 or 9 for computer-to-plate.
13. A process of producing an aluminium alloy sheet/strip/foil for printing plate using
the alloy according to claim 1,
characterized in comprising the steps of:
1) adding the alloy components as defined in claim 1 into a remelting furnace, melting,
refining, inclusion removing, degassing and filtering, followed by casting into a
sheet ingot with a thickness of about 500 to about 650 mm;
2)sawing the head and butt of the sheet ingot, scalping, and then heating to a temperature
of about 500 to about 600 degrees centigrade for about 2 to about 12 hours; and hot
rolling the sheet ingot into a strip with a thickness of about 2.0 to about 5.0 mm
at a temperature of about 250 to about 320 degrees centigrade;
3) cold rolling the strip to a thickness of about 1 to about 3 mm, wherein the roll
has a roughness, Ra, of about 0.30 to about 0.80 µm;
4) annealing the cold rolled strip from step 3) in an annealing furnace at a temperature
of about 350 to about 450 degrees centigrade, and holding the temperature for about
2 to about 4 hours;
5) continuing rolling the strip from step 4) on a cold roller to a thickness of about
0.14 to about 0.4 mm, with a Ra of about 0.15 to about 0.30 µm; and
6) cleaning the strip from step 5), edge trimming, and tension leveling, to obtain
the aluminium alloy sheet, strip or foil.
1. Aluminiumlegierung, umfassend Al, Si, Fe, Mg, Cu, Ti und gegebenenfalls andere Verunreinigunggen,
dadurch gekennzeichnet, dass die Komponenten, in Gewichtsanteilen, umfassen: Si: 0,04-0,1 %, Fe: 0,3-0,38 %, Mg:
0,07-0,10 %, Cu: 0,004-0,01 %, Ti: 0,003-0,02 %; jede der anderen Verunreinigungen
ist in einem Gewichtsanteil von nicht mehr als 0,03 % vorhanden; und der Rest ist
Al.
2. Aluminiumlegierung nach Anspruch 1, dadurch gekennzeichnet, dass Mg/Fe>=0,125.
3. Aluminiumlegierung nach Anspruch 1, dadurch gekennzeichnet, dass Cu in einer Menge von nicht weniger als 0,0045 %, vorzugsweise nicht weniger als
0,005 % enthalten ist; und/oder Cu in einer Menge von nicht mehr als 0,009 %, vorzugsweise
von nicht mehr als 0,008 % enthalten ist.
4. Aluminiumlegierung nach Anspruch 1, dadurch gekennzeichnet, dass Ti in einer Menge von nicht weniger als 0,004 %, vorzugsweise nicht weniger als 0,005
% enthalten ist; und/oder Ti in einer Menge von nicht mehr als 0,019 %, vorzugsweise
von nicht mehr als 0,017 % enthalten ist.
5. Aluminiumlegierung nach Anspruch 1, dadurch gekennzeichnet, dass die Verunreinigungen Li, Na,Pb, Be, Zn und/oder V umfassen.
6. Aluminiumlegierung nach Anspruch 1, dadurch gekennzeichnet, dass die Gesamtmenge der Verunreinigungen höchsten 0,1 Gew.-% beträgt.
7. Aluminiumlegierung nach Anspruch 1, dadurch gekennzeichnet, dass Al in einer Menge von nicht weniger als 99,30 % enthalten ist.
8. Gegenstand, umfassend die Aluminiumlegierung nach Anspruch 1.
9. Gegenstand nach Anspruch 8, dadurch gekennzeichnet, dass er in Form eines Bandes, einer Folie oder eines Blechs vorliegt.
10. Gegenstand nach Anspruch 9, dadurch gekennzeichnet, dass das Aluminiumblech/das Aluminiumband/die Aluminiumfolie eine Dicke von etwa 0,14
mm bis etwa 0,5 mm, vorzugsweise etwa 0,18 mm bis etwa 0,38 mm aufweist.
11. Gegenstand nach Anspruch 9 oder 10, dadurch gekennzeichnet, dass er bei Raumtemperatur eine Zugfestigkeit von etwa 175 bis etwa 210 MPa, eine Streckgrenze
von etwa 170 bis etwa 200 MPa, und/oder eine Dehnung von etwa 2 % bis etwa 6 aufweist;
und
dadurch, dass durch eine simulierte Brennbedingungsbehandlung bei einer Temperatur
von 240 Grad Celsius für 10 Minuten, der Aluminiumlegierungsgegenstand, nach dem Abkühlen,
eine Zugfestigkeit von etwa 145 bis etwa 170 MPa, eine Streckgrenze von etwa 135 bis
etwa 155 MPa und/oder eine Dehnung von etwa 3 % bis etwa 8 % aufweist.
12. Verwendung des Gegenstands nach Anspruch 9 oder 10 für Computer-to-Plate.
13. Verfahren zur Herstellung eines Aluminiumblechs/eines Aluminiumbandes/einer Aluminiumfolie
zum Drucken einer Platte unter Verwendung der Legierung nach Anspruch 1,
dadurch gekennzeichnet, dass es die folgenden Schritte umfasst:
1) Zugeben der Legierungskomponenten gemäß Anspruch 1 in einen Umschmelzofen, Schmelzen,
Feinen, Entfernen von Einschlüssen, Entgasen und Filtern, gefolgt vom Gießen zu einem
Walzbarren mit einer Dicke von etwa 500 bis etwa 650 mm;
2) Sägen von Kopf und Stumpf des Walzbarrens, Fräsen und dann Erhitzen auf eine Temperatur
von etwa 500 bis etwa 600 Grad Celsius für etwa 2 bis etwa 12 Stunden; und Warmwalzen
des Walzbarrens zu einen Band mit einer Dicke von etwa 2,0 bis 5,0 mm bei einer Temperatur
von etwa 250 bis etwa 320 Grad Celsius;
3) Kaltwalzen des Bands auf eine Dicke von etwa 1 bis etwa 3 mm, wobei die Walze eine
Rauheit, Ra, von etwa 0,30 bis etwa 0,80 um aufweist;
4) Tempern des kaltgewalzten Bandes aus Schritt 3) in einem Glühofen bei einer Temperatur
von etwa 350 bis etwa 450 Grad Celsius und Halten der Temperatur für etwa 2 bis etwa
4 Stunden;
5) Fortsetzen des Walzens des Bandes aus Schritt 4) auf einer Kaltwalze auf eine Dicke
von etwa 0,14 bis etwa 0,4 mm mit einer Ra von etwa 0,15 bis etwa 0,30 µm; und
6) Reinigen des Bandes aus Schritt 5), Kantenschneiden und Spannungsausgleich, um
das Aluminiumlegierungsblech, das Aluminiumlegierungsband oder die Aluminiumlegierungsfolie
zu erhalten.
1. Alliage d'aluminium, comprenant de l'Al, du Si, du Fe, du Mg, du Cu, du Ti et facultativement
d'autres impuretés, caractérisé en ce que les composants sont compris en des quantités en poids de : Si : 0,04 à 0,1 %, Fe
: 0,3 à 0,.8 %, Mg : 0,07 à 0,10 %, Cu : 0,004 à 0,01 %, Ti :0,003 à 0,02 % ; l'une
quelconque des autres impuretés en une quantité en poids pas supérieure à 0,03 % ;
et le reste est l'Al.
2. Alliage d'aluminium selon la revendication 1, caractérisé en ce que Mg/Fe ≥ 0,125.
3. Alliage d'aluminium selon la revendication 1, caractérisé en ce que le Cu est compris en une quantité pas inférieure à 0,0045 %, de préférence pas inférieure
à 0,005 % ; et/ou le Cu est compris en une quantité pas supérieure à 0,009 %, de préférence
pas supérieure à 0,008 %.
4. Alliage d'aluminium selon la revendication 1, caractérisé en ce que le Ti est compris en une quantité pas inférieure à 0,004 %, de préférence pas inférieure
à 0,005 % ; et/ou le Ti est compris en une quantité pas supérieure à 0,019 %, de préférence
pas supérieure à 0,017 %.
5. Alliage d'aluminium selon la revendication 1, caractérisé en ce que les impuretés comprennent du Li, du Na, du Pb, du Be, du Zn et/ou du V.
6. Alliage d'aluminium selon la revendication 1, caractérisé en ce que la quantité totale des impuretés est d'au plus 0,1 % en poids.
7. Alliage d'aluminium selon la revendication 1, caractérisé en ce que l'Al est compris en une quantité pas inférieure à 99,30 %.
8. Article comprenant un alliage d'aluminium selon la revendication 1.
9. Article selon la revendication 8, caractérisé en ce qu'il se trouve sous la forme d'une bande, d'une feuille de métal ou d'une feuille.
10. Article selon la revendication 9, caractérisé en ce que la feuille/bande/feuille métallique d'aluminium a une épaisseur d'environ 0,14 mm
à environ 0,5 mm, de préférence d'environ 0,18 mm à environ 0,38 mm.
11. Article selon la revendication 8 ou 9, caractérisé en ce qu'il a une résistance à la traction d'environ 175 à environ 210 MPa, une limité d'élasticité
d'environ 170 à environ 200 MPa, et/ou un allongement d'environ 2 % à environ 6 %,
à température ambiante ; et
en ce que par l'intermédiaire d'un traitement dans une condition de cuisson simulée à une température
de 240 °C pendant 10 minutes, l'article en alliage d'aluminium, après refroidissement,
a une résistance en traction d'environ 145 à environ 170 MPa, une limite d'élasticité
d'environ 135 à environ 155 MPa, et/ou un allongement d'environ 3 % à environ 8 %.
12. Utilisation de l'article selon la revendication 8 ou 9 pour un système direct ordinateur/plaque.
13. Procédé de production d'une feuille/bande/feuille métallique d'aluminium pour imprimer
une plaque en utilisant l'alliage selon la revendication 1,
caractérisé en ce qu'il comprend les étapes suivantes :
1) ajout des composants de l'alliage selon la revendication 1 dans un four à refondre,
fusion, raffinage, élimination des inclusions, dégazage et filtrage, suivis par la
coulée en un lingot de laminage ayant une épaisseur d'environ 500 à environ 650 mm
;
2) sciage de la tête et du pied du lingot de laminage, scalpage, puis chauffage à
une température d'environ 500 à environ 600 °C pendant environ 2 à environ 12 heures
; et laminage à chaud du lingot de laminage en une avec une épaisseur d'environ 2,0
à environ 5,0 mm à une temperature d'environ 250 à environ 320 °C ;
3) laminage à froid de la bande à une épaisseur d'environ 1 à environ 3 mm, dans lequel
le rouleau a une rugosité, Ra, d'environ 0,30 à environ 0,80 µm
4) recuit de la bande laminée à froid de l'étape 3) dans un four de recuit à une temperature
d'environ 350 à environ 450 °C, et maintien de la température pendant environ 2 à
environ 4 heures ;
5) poursuite du laminage de la bande de l'étape 4) sur un rouleau froid à une épaisseur
d'environ 0,14 à environ 0,4 mm, avec une Ra d'environ 0,15 à environ 0,30 µm ; et
6) nettoyage de la bande de l'étape 5), cisaillage de rives, et planage sous tension,
pour obtenir la feuille, bande ou feuille métallique d'aluminium.