EP4050115A1 - Durable aluminium alloy sheet for decorative applications - Google Patents
Durable aluminium alloy sheet for decorative applications Download PDFInfo
- Publication number
- EP4050115A1 EP4050115A1 EP21159556.6A EP21159556A EP4050115A1 EP 4050115 A1 EP4050115 A1 EP 4050115A1 EP 21159556 A EP21159556 A EP 21159556A EP 4050115 A1 EP4050115 A1 EP 4050115A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- sheet according
- trim
- anyone
- sheet
- slab
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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- 229910000838 Al alloy Inorganic materials 0.000 title claims abstract description 16
- 229910052749 magnesium Inorganic materials 0.000 claims abstract description 11
- 239000012535 impurity Substances 0.000 claims abstract description 10
- 229910052782 aluminium Inorganic materials 0.000 claims abstract description 8
- 238000000137 annealing Methods 0.000 claims abstract description 8
- 239000004411 aluminium Substances 0.000 claims abstract description 7
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims abstract description 7
- 238000000034 method Methods 0.000 claims abstract description 7
- 238000005097 cold rolling Methods 0.000 claims abstract description 6
- 229910052742 iron Inorganic materials 0.000 claims description 9
- 229910052802 copper Inorganic materials 0.000 claims description 8
- 229910052804 chromium Inorganic materials 0.000 claims description 6
- 229910052748 manganese Inorganic materials 0.000 claims description 6
- 238000007669 thermal treatment Methods 0.000 claims description 2
- 239000000203 mixture Substances 0.000 abstract description 9
- 238000005266 casting Methods 0.000 abstract description 4
- 238000005098 hot rolling Methods 0.000 abstract description 3
- 239000010949 copper Substances 0.000 description 17
- 239000011777 magnesium Substances 0.000 description 14
- 229910045601 alloy Inorganic materials 0.000 description 13
- 239000000956 alloy Substances 0.000 description 13
- 239000011701 zinc Substances 0.000 description 9
- 239000011248 coating agent Substances 0.000 description 4
- 238000000576 coating method Methods 0.000 description 4
- 230000007797 corrosion Effects 0.000 description 4
- 238000005260 corrosion Methods 0.000 description 4
- 229910052725 zinc Inorganic materials 0.000 description 4
- 230000007547 defect Effects 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 229910000831 Steel Inorganic materials 0.000 description 2
- 238000007792 addition Methods 0.000 description 2
- 230000000593 degrading effect Effects 0.000 description 2
- 238000000265 homogenisation Methods 0.000 description 2
- 238000004806 packaging method and process Methods 0.000 description 2
- 238000001953 recrystallisation Methods 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 239000011573 trace mineral Substances 0.000 description 2
- 235000013619 trace mineral Nutrition 0.000 description 2
- 239000002966 varnish Substances 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- 229910000861 Mg alloy Inorganic materials 0.000 description 1
- 229910000914 Mn alloy Inorganic materials 0.000 description 1
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000004566 building material Substances 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 238000005034 decoration Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 230000006911 nucleation Effects 0.000 description 1
- 238000010899 nucleation Methods 0.000 description 1
- 239000003973 paint Substances 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 238000007493 shaping process Methods 0.000 description 1
- 238000010112 shell-mould casting Methods 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000009864 tensile test Methods 0.000 description 1
- 239000002023 wood Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C21/00—Alloys based on aluminium
- C22C21/06—Alloys based on aluminium with magnesium as the next major constituent
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C21/00—Alloys based on aluminium
- C22C21/06—Alloys based on aluminium with magnesium as the next major constituent
- C22C21/08—Alloys based on aluminium with magnesium as the next major constituent with silicon
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
- C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
- C22F1/04—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of aluminium or alloys based thereon
- C22F1/047—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of aluminium or alloys based thereon of alloys with magnesium as the next major constituent
Definitions
- the invention relates to the field of decorative parts made of aluminium alloys which are formable. These parts are coated before forming for decorative purposes and/or to be durable. The alloy after the curing of the coating must be hard enough to present a good dent or scratch resistance.
- the invention relates more particularly to aluminium alloy sheets of the AA3XXX and AA5xxx series with a composition and manufacturing process that are particularly suitable for this type of application and offering,
- Aluminium alloys are commonly used in the manufacturing of decorative parts, particularly for the automotive industry, but also in the household appliance and medical device industries, in competition with wood, steel and plastics. These parts are generally coated, typically with a varnish or a paint.
- interior decorative elements are produced, for example for high-usage door handles, gearbox trims, light-resistant and shockproof trim elements for the center console, trims and/or panels on the dashboard and/or doors, capacitive function elements and exterior elements are also produced such as, in particular, the window surrounds, body side or door trim strips, beltlines, tailgate trim strips, radiator grille trim, bumper piping, hubcaps, wheel hub cover....
- Two types of products are currently available on the market: extruded profiles and shaped sheets.
- the predominant alloy types used for sheets are AA 1XXX, AA3XXX, AA5XXX and 8XXX alloys.
- AA5005 aluminium alloy rolled products with different heat treatment states are widely used in conductors, kitchenware, dashboards, architectural decorations, building materials, vehicle interior and exterior materials.
- WO/2014/203077 relates to a method for manufacturing an outer moulding ring of a motor vehicle, in particular such as a window frame or body shell moulding, made of an aluminium alloy, by shaping and polishing a sheet or strip made by continuous vertical casting of a high-purity alloy sheet of series AA5xxx.
- a window frame or body shell moulding made of an aluminium alloy
- the invention aims to provide sheets made of aluminium alloys that are particularly suitable to make decorative parts and offer a high scratch resistance, with simultaneously being formable, corrosion resistant and providing a nice surface aspect.
- a first subject of the invention is a sheet made of an aluminium alloy comprising, by weight %
- Another subject of the invention is a method to make a sheet according to the invention wherein,
- Yet another subject of the invention is the use of a sheet according to the invention to make a coated decorative part preferably a decorative part for an automobile, or a household appliance or a medical device.
- a sheet is a rolled product with a rectangular cross section, the uniform thickness of which is between 0.20 mm and 6 mm. In the context of the invention, a sheet is not a clad sheet.
- a preferred thickness of the sheet of the invention is from 0.35 mm to 1.5 mm and more preferably from 0.50 mm to 1.0 mm.
- the inventors have found a sheet composition which solves the problem.
- the sheet of the invention provides higher scratch resistance with similar formability and corrosion resistance than the known products.
- the present inventors had first considered to use a high Mg content such as 1.8 wt.% in order to improve scratch resistance, however the products obtained had surface defects related to Lüders bands / Portevin-Le Chatelier bands observed during forming. In order to avoid these bands, the magnesium content has to be at most 1.3 wt.%.
- a minimum Mg content of 0.8 wt.% is needed to obtain sufficient strength and scratch resistance.
- the minimum Mg content is 0.9 wt.%.
- the maximum Mg content is 1.2 wt.% and more preferably 1.1 wt.%. In a preferred embodiment by wt.%, Mg : 0,9 - 1.1. Mn is used to improve strength and scratch resistance.
- the Mn content is from 0.8 to 1.2 wt.%.
- the minimum Mn content is 0.85 wt.%, more preferably 0.90 wt.% and preferentially 0.95 wt.%.
- the maximum Mn content is 1.15 wt.% and more preferably 1.10 wt.% and preferentially 1.05 wt.%. In a preferred embodiment by wt.%, Mn : 0.85 - 1.15 and preferably Mn : 0.95 - 1.05. Cu is added to improve strength and scratch resistance.
- the Cu content is from 0.05 to 0.30 wt.%.
- the minimum Cu content is 0.10 wt.%, more preferably 0.15 wt.%.
- the maximum Cu content is 0.25 wt.% and more preferably 0.20 wt.%. In a preferred embodiment by wt.%, Cu : 0.10 - 0.25 and preferably Cu : 0.15 - 0.20.
- the Cr content is from 0.05 to 0.30 wt.%.
- the minimum Cr content is 0.10 wt.%, more preferably 0.15 wt.%.
- the maximum Cr content is 0.27 wt.% and more preferably 0.25 wt.%.
- Fe and Si have to be limited to a maximum of 0.4 wt.% and 0.3 wt.%, respectively, to obtain the desired formability.
- a minimum content is however beneficial for surface aspects by limiting, for example, orange peel aspect on formed parts.
- the minimum Fe content is 0.15 wt.%, more preferably 0.20 wt.%.
- the maximum Fe content is 0.35 wt.% and more preferably 0.30 wt.%.
- the minimum Si content is 0.10 wt.%, more preferably 0.15 wt.% and even more preferably 0.18 wt.%.
- the maximum Si content is 0.25 wt.% and more preferably 0.23 wt.%. With the selected preferred Fe and Si contents recyclability of the alloy is quite satisfactory.
- the Zn content is limited to a maximum of 0.25 wt.%. Further limiting the zinc content usually degrades recyclability. In an embodiment the Zn content is at least 0.01 wt.%. In another embodiment the Zn content is however limited to an impurity level of less than 0.01 wt.% to improve surface aspect.
- the Ti content is limited to a maximum of 0.15 wt.%. Ti may be added to improve grain size control, in particular during casting. In an embodiment the Ti content is at least 0.01 wt.%.
- the maximum Ti content is 0.10 wt.% and more preferably 0.05 wt.%.
- Other elements are impurities whose content is less than 0.05 wt.% each and 0.15 wt.% total.
- the method to make a sheet according to the invention comprises casting a slab with a composition according to the invention, homogenizing, hot and cold rolling the slab, annealing and tension leveling.
- the slab is homogenized at a temperature of at least 550 °C, preferably of at least 575 °C.
- the maximum homogenizing temperature is defined to avoid incipient melting, it is typically 630 °C or 620 °C.
- the homogenization is carried out during at least one hour and at most 72 hours.
- the slab is usually scalped.
- the homogenized slab is then hot rolled to an intermediate rolled product having a thickness from 3 to 10 mm.
- the initial hot rolling temperature is at least 430 °C.
- the intermediate rolled product is then cold rolled into a sheet, optionally with an intermediate annealing during cold rolling.
- the intermediate rolled product is first cold rolled to a first thickness between 1.5 and 8.0 mm, then annealed at a temperature from 300 °C to 450 °C and then cold rolled to a second thickness between 0.20 mm and 6 mm.
- the intermediate rolled product is directly cold rolled into a sheet with a thickness between 0.20 mm and 6 mm.
- the sheet is then annealed at a temperature from 300 °C to 450 °C.
- the annealing is designed to obtain full recrystallization.
- the temper after annealing is named O-temper.
- the sheet undergoes tension leveling with a stretching of at least 1 %.
- Tension leveling is needed to improve flatness of the product.
- a minimum stretching during tension leveling of 1.8 % and more preferably 2 % is performed in order to improve the yield strength after curing of the coating, typically of 1 to 10 minutes at 150 to 230 °C.
- a maximum stretching of 3.5 %, more preferably 3 %, during tension leveling is performed.
- the sheets of the invention have preferably, after tension leveling a TYS in the longitudinal direction of at least 130 MPa and A% of at least 16 % and after further thermal treatment of 4 minutes at 195 °C, typically corresponding to curing of the coating, a TYS in the longitudinal direction of at least 110 MPa and A% of at least 16 %.
- the sheets according to the invention are preferably used to make a coated decorative part, preferably for an automobile, or a household appliance or a medical device.
- an automobile interior finishing element selected in the list consisting of a door handle, a gearbox trim, a trim element for a center console, a trim for a dashboard, a panel for a dashboard, a trim for a door, a panel for a door and a capacitive function element or an automobile exterior element selected in the list consisting of a window surrounds, a body side or door trim strip, a tailgate trim strip, a radiator grille trim, wheel hub cover, a beltline and a bumper piping.
- Table 1 The alloys disclosed in Table 1 where cast in the form of small ingots of dimension 70 mm x 190 mm x 1500 mm. Alloy C is according to the invention.
- Table 1 Composition in wt.% Alloy Si % Fe % Cu % Mn % Mg % Cr % Zn Ti A 0.11 0.20 0.17 0.97 1.1 ⁇ 0.01 ⁇ 0.01 0.01 B 0.10 0.19 ⁇ 0.01 1.02 1.3 0.18 ⁇ 0.01 0.01 C 0.11 0.20 0.16 1.00 1.1 0.21 ⁇ 0.01 0.01
- the ingots were scalped and homogenized 3 hours at 600 °C.
- the ingots were hot rolled with a starting temperature above 500 °C down to a thickness of 7.6 mm and cold rolled to a thickness of 2.5 mm.
- An intermediate annealing of 1 hour at 340 °C was carried out and the cold rolling was continued to sheets with a thickness of 0.76 mm.
- the sheets were annealed 1 hour at 340 °C to obtain a fully recrystallized grain structure.
- the sheets were then tension-levelled with a stretching of 2.5 % in the rolling direction.
- a coating curing simulation of 4 min at 195 °C was carried out.
- the test range used is 0 to 20N (range 3 of the apparatus).
- the test wheel used is the provided steel disc.
- the hardness tester is placed perpendicularly onto the surface to be tested and is pressed down so that the guide wheels touch the surface. In this way the preset force acting upon the test disc is fully effective on the test surface. The instrument is then moved, the wheel being over the specimen to be tested.
- the scratch resistance is related to maximum force at which the test body does not leave any trace on the test surface.
- the results are presented in Table 3 in a comparative manner compared to a typical requirement "+” slightly above requirement, "++” significantly above requirement.
- Table 3 Scratch resistance of the sheets Alloy scratch resistance A + B + C ++
- composition according to the invention an improved scratch resistance is obtained, without degrading elongation before or after the curing.
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Laminated Bodies (AREA)
- Metal Rolling (AREA)
- Coating With Molten Metal (AREA)
- Heat Treatment Of Sheet Steel (AREA)
Abstract
The invention relates to improved sheets for decorative and formable parts made of an aluminium alloy which comprises, in wt.%, Mg : 0.8 - 1.3, Mn : 0.8 - 1.2, Cu: 0.05 - 0.30, Cr : 0.05 - 0.30, Fe : ≤ 0.4, Si : ≤ 0.3, Zn : ≤ 0.25, Ti : ≤ 0.15, impurities < 0.05 each and < 0.15 total, remainder aluminium. The method to make a sheet according to the invention comprises casting a slab with a composition according to the invention, homogenizing, hot and cold rolling the slab, annealing and tension leveling. The sheet according to the invention are particularly useful to make a coated decorative part preferably a decorative part for an automobile, or a household appliance or a medical device.
Description
- The invention relates to the field of decorative parts made of aluminium alloys which are formable. These parts are coated before forming for decorative purposes and/or to be durable. The alloy after the curing of the coating must be hard enough to present a good dent or scratch resistance.
- The invention relates more particularly to aluminium alloy sheets of the AA3XXX and AA5xxx series with a composition and manufacturing process that are particularly suitable for this type of application and offering,
- Aluminium alloys are commonly used in the manufacturing of decorative parts, particularly for the automotive industry, but also in the household appliance and medical device industries, in competition with wood, steel and plastics. These parts are generally coated, typically with a varnish or a paint.
- In the case of the automotive industry, interior decorative elements are produced, for example for high-usage door handles, gearbox trims, light-resistant and shockproof trim elements for the center console, trims and/or panels on the dashboard and/or doors, capacitive function elements and exterior elements are also produced such as, in particular, the window surrounds, body side or door trim strips, beltlines, tailgate trim strips, radiator grille trim, bumper piping, hubcaps, wheel hub cover....
Two types of products are currently available on the market: extruded profiles and shaped sheets. - The predominant alloy types used for sheets are AA 1XXX, AA3XXX, AA5XXX and 8XXX alloys. AA5005 aluminium alloy rolled products with different heat treatment states are widely used in conductors, kitchenware, dashboards, architectural decorations, building materials, vehicle interior and exterior materials.
-
WO/2014/203077 relates to a method for manufacturing an outer moulding ring of a motor vehicle, in particular such as a window frame or body shell moulding, made of an aluminium alloy, by shaping and polishing a sheet or strip made by continuous vertical casting of a high-purity alloy sheet of series AA5xxx.
Several patents disclose Al-Mn-Mg alloys, mainly for packaging applications: -
EP0504077 relates to Al-based alloys intended for deep drawing and/or drawing and exhibiting high mechanical strength characteristics as well as good isotropy (low distortion wedge content) and good cold processability having the following compositions by weight (%): Fe ≦ 0.25 - Si ≦ 0.25 - Mn from 0.8 to 1.6 - Mg from 0.7 to 2.5 - Cu from 0.20 to 0.6 - Cr from 0 to 0.35 - Ti from 0 to 0.1 - V from 0 to 0.1 - others each ≦ 0,05, total ≦ 0,15, remainder Al. -
WO/2018/143376 relates to an aluminium alloy sheet which contains 0.05-0.60 mass% of Si, 0.05-0.80 mass% of Fe, 0.05-0.25 mass% of Cu, 0.80-1.50 mass% of Mn, 0.80-1.50 mass% of Mg, Al, and incidental impurities. -
WO2015140833 relates to an aluminium alloy for can bodies containing Si: 0.10-0.60 mass%, Fe: 0.10-0.80%, Cu: 0.05-0.25%, Mn: 0.80-1.50%, Mg: 0.80-1.30% and the remainder being obtained from Al and unavoidable impurities. -
WO/2016/149061 relates to aluminium alloys for making packaging products such as bottles and cans comprising 0.1-1.6 wt. % Mn, 0.1-3 wt. % Mg, 0.1-1.5 wt. % Cu, 0.2-0.7 wt. % Fe, 0.10-0.6 wt. % Si, up to 0.3 wt. % Cr, up to 0.6 wt. % Zn, up to 0.2 wt. % Ti, 0.05 wt. % for each trace element, <0.15 wt. % for total trace elements and remainder Al. -
WO/2016/100800 relates to compositions and methods comprising aluminium alloy system useful for aluminium bottle applications comprising about 0.15-0.50 % Si, 0.35-0.65 % Fe, 0.05-0.30 % Cu, 0.60-1.10 % Mn, 0.80-1.30 % Mg, 0.000-0.0080 % Cr, 0.000-0.500 % Zn, 0.000-0.080 % Ti, up to 0.15 % of impurities, with the remainder as Al. - The invention aims to provide sheets made of aluminium alloys that are particularly suitable to make decorative parts and offer a high scratch resistance, with simultaneously being formable, corrosion resistant and providing a nice surface aspect.
- A first subject of the invention is a sheet made of an aluminium alloy comprising, by weight %
- Mg : 0.8 - 1.3,
- Mn : 0.8 - 1.2,
- Cu: 0.05 - 0.30,
- Cr : 0.05 - 0.30,
- Fe : ≤ 0.4,
- Si : ≤ 0.3,
- Zn : ≤ 0.25,
- Ti : ≤ 0.15,
- Another subject of the invention is a method to make a sheet according to the invention wherein,
- (a) a slab is cast of an aluminium alloy comprising, by weight %
- Mg : 0.8 - 1.3,
- Mn : 0.8 - 1.2,
- Cu: 0.05 - 0.30,
- Cr : 0.05 - 0.30,
- Fe : ≤ 0.4,
- Si : ≤ 0.3,
- Zn : ≤ 0.25,
- Ti : ≤ 0.15,
- (b) the slab is homogenized at a temperature of at least 550 °C,
- (c) the homogenized slab is hot rolled to an intermediate rolled product having a thickness from 3 to 10 mm,
- (d) the intermediate rolled product is cold rolled into a sheet, optionally with an intermediate annealing during cold rolling,
- (e) the sheet is annealed at a temperature from 300°C to 400 °C and undergoes tension leveling with a stretching of at least 1%.
- Yet another subject of the invention is the use of a sheet according to the invention to make a coated decorative part preferably a decorative part for an automobile, or a household appliance or a medical device.
- Unless otherwise indicated, all indications concerning the chemical composition of alloys are expressed as a percentage by weight based on the total weight of the alloy. The expression 1.4 Cu means that the copper content expressed in % by weight is multiplied by 1.4. The designation of the alloys is made in accordance with the regulations of The Aluminium Association, known to those skilled in the art.
The static mechanical properties in tension, in other words the ultimate tensile strength UTS, the conventional yield strength at 0.2 % elongation TYS, and the elongation at break A%, are determined by a tensile test according to standard NF EN ISO 6892-1. The elongation (A%) at break was measured using a 50 mm base extensometer and is reported under A50. Scratch resistance was measured according to the method described in the example.
Unless stated otherwise, the definitions of standard EN 12258 (2012) apply. A sheet is a rolled product with a rectangular cross section, the uniform thickness of which is between 0.20 mm and 6 mm. In the context of the invention, a sheet is not a clad sheet. - A preferred thickness of the sheet of the invention is from 0.35 mm to 1.5 mm and more preferably from 0.50 mm to 1.0 mm.
The inventors have found a sheet composition which solves the problem. In particular, with the simultaneous addition of Cu and Cr to an Al-Mg-Mn alloy, the sheet of the invention provides higher scratch resistance with similar formability and corrosion resistance than the known products.
The present inventors had first considered to use a high Mg content such as 1.8 wt.% in order to improve scratch resistance, however the products obtained had surface defects related to Lüders bands / Portevin-Le Chatelier bands observed during forming. In order to avoid these bands, the magnesium content has to be at most 1.3 wt.%. A minimum Mg content of 0.8 wt.% is needed to obtain sufficient strength and scratch resistance. Preferably the minimum Mg content is 0.9 wt.%. Preferably the maximum Mg content is 1.2 wt.% and more preferably 1.1 wt.%. In a preferred embodiment by wt.%, Mg : 0,9 - 1.1.
Mn is used to improve strength and scratch resistance. The Mn content is from 0.8 to 1.2 wt.%. Preferably the minimum Mn content is 0.85 wt.%, more preferably 0.90 wt.% and preferentially 0.95 wt.%. Preferably the maximum Mn content is 1.15 wt.% and more preferably 1.10 wt.% and preferentially 1.05 wt.%. In a preferred embodiment by wt.%, Mn : 0.85 - 1.15 and preferably Mn : 0.95 - 1.05.
Cu is added to improve strength and scratch resistance. The Cu content is from 0.05 to 0.30 wt.%. Preferably the minimum Cu content is 0.10 wt.%, more preferably 0.15 wt.%. Preferably the maximum Cu content is 0.25 wt.% and more preferably 0.20 wt.%. In a preferred embodiment by wt.%, Cu : 0.10 - 0.25 and preferably Cu : 0.15 - 0.20.
Cr is added to improve strength and scratch resistance. The Cr content is from 0.05 to 0.30 wt.%. Preferably the minimum Cr content is 0.10 wt.%, more preferably 0.15 wt.%. Preferably the maximum Cr content is 0.27 wt.% and more preferably 0.25 wt.%. In a preferred embodiment by wt. % Cr : 0.10 - 0.30 and preferably Cr : 0.15 - 0.25.
Fe and Si have to be limited to a maximum of 0.4 wt.% and 0.3 wt.%, respectively, to obtain the desired formability. A minimum content is however beneficial for surface aspects by limiting, for example, orange peel aspect on formed parts. The inventors believe that Fe and Si additions increase the Particle Stimulated Nucleation effect during recrystallization compared to a purer chemistry, which leads to smaller grains and limits the orange peel on formed parts. Preferably the minimum Fe content is 0.15 wt.%, more preferably 0.20 wt.%. Preferably the maximum Fe content is 0.35 wt.% and more preferably 0.30 wt.%. In a preferred embodiment by wt.%, Fe : 0.15 - 0.35 and/or Si : 0.10 - 0.25.
Preferably the minimum Si content is 0.10 wt.%, more preferably 0.15 wt.% and even more preferably 0.18 wt.%. Preferably the maximum Si content is 0.25 wt.% and more preferably 0.23 wt.%.
With the selected preferred Fe and Si contents recyclability of the alloy is quite satisfactory.
The Zn content is limited to a maximum of 0.25 wt.%. Further limiting the zinc content usually degrades recyclability. In an embodiment the Zn content is at least 0.01 wt.%.
In another embodiment the Zn content is however limited to an impurity level of less than 0.01 wt.% to improve surface aspect.
The Ti content is limited to a maximum of 0.15 wt.%. Ti may be added to improve grain size control, in particular during casting. In an embodiment the Ti content is at least 0.01 wt.%. Preferably the maximum Ti content is 0.10 wt.% and more preferably 0.05 wt.%.
Other elements are impurities whose content is less than 0.05 wt.% each and 0.15 wt.% total.
The method to make a sheet according to the invention comprises casting a slab with a composition according to the invention, homogenizing, hot and cold rolling the slab, annealing and tension leveling.
The slab is homogenized at a temperature of at least 550 °C, preferably of at least 575 °C. The maximum homogenizing temperature is defined to avoid incipient melting, it is typically 630 °C or 620 °C. Preferably, the homogenization is carried out during at least one hour and at most 72 hours. Before or after homogenization, the slab is usually scalped.
The homogenized slab is then hot rolled to an intermediate rolled product having a thickness from 3 to 10 mm. Preferably the initial hot rolling temperature is at least 430 °C.
The intermediate rolled product is then cold rolled into a sheet, optionally with an intermediate annealing during cold rolling. In an embodiment the intermediate rolled product is first cold rolled to a first thickness between 1.5 and 8.0 mm, then annealed at a temperature from 300 °C to 450 °C and then cold rolled to a second thickness between 0.20 mm and 6 mm. In another embodiment, the intermediate rolled product is directly cold rolled into a sheet with a thickness between 0.20 mm and 6 mm. - The sheet is then annealed at a temperature from 300 °C to 450 °C. The annealing is designed to obtain full recrystallization. The temper after annealing is named O-temper. Finally, the sheet undergoes tension leveling with a stretching of at least 1 %. Tension leveling is needed to improve flatness of the product. Advantageously, a minimum stretching during tension leveling of 1.8 % and more preferably 2 %, is performed in order to improve the yield strength after curing of the coating, typically of 1 to 10 minutes at 150 to 230 °C. In order to prevent surface defects and preserve good formability a maximum stretching of 3.5 %, more preferably 3 %, during tension leveling is performed.
The sheets of the invention have preferably, after tension leveling a TYS in the longitudinal direction of at least 130 MPa and A% of at least 16 % and after further thermal treatment of 4 minutes at 195 °C, typically corresponding to curing of the coating, a TYS in the longitudinal direction of at least 110 MPa and A% of at least 16 %. The sheets according to the invention are preferably used to make a coated decorative part, preferably for an automobile, or a household appliance or a medical device. Preferably they are used to make an automobile interior finishing element selected in the list consisting of a door handle, a gearbox trim, a trim element for a center console, a trim for a dashboard, a panel for a dashboard, a trim for a door, a panel for a door and a capacitive function element or an automobile exterior element selected in the list consisting of a window surrounds, a body side or door trim strip, a tailgate trim strip, a radiator grille trim, wheel hub cover, a beltline and a bumper piping. - The details of the invention will be understood better with the help of the example below, which is not, however, restrictive in its scope.
- The alloys disclosed in Table 1 where cast in the form of small ingots of dimension 70 mm x 190 mm x 1500 mm. Alloy C is according to the invention.
Table 1: Composition in wt.% Alloy Si % Fe % Cu % Mn % Mg % Cr % Zn Ti A 0.11 0.20 0.17 0.97 1.1 < 0.01 <0.01 0.01 B 0.10 0.19 < 0.01 1.02 1.3 0.18 <0.01 0.01 C 0.11 0.20 0.16 1.00 1.1 0.21 <0.01 0.01 - The ingots were scalped and homogenized 3 hours at 600 °C. The ingots were hot rolled with a starting temperature above 500 °C down to a thickness of 7.6 mm and cold rolled to a thickness of 2.5 mm. An intermediate annealing of 1 hour at 340 °C was carried out and the cold rolling was continued to sheets with a thickness of 0.76 mm. The sheets were annealed 1 hour at 340 °C to obtain a fully recrystallized grain structure. The sheets were then tension-levelled with a stretching of 2.5 % in the rolling direction.
In order to obtain representative mechanical properties of the finished part, which is formed and coated, a coating curing simulation of 4 min at 195 °C was carried out. Mechanical properties characterized in the longitudinal direction L are provided in Table 2.Table 2: Mechanical properties of the sheets Recrystallized + stretching 2.5 % by tension leveling + 4 min at 195°C Alloy TYS (MPa) TYS (MPa) A50 (%) TYS (MPa) UTS (MPa) TYS/UTS (-) A50 (%) A 65 126 17.2 105 182 0.57 15.8 B 64 127 18.2 102 177 0.58 18.3 C 68 135 17.8 113 191 0.59 17.0 - All samples were also coated with the same varnish thickness and scratch resistance was tested with a scratch hardness tester (Erichsen Model 435 pen).
The test range used is 0 to 20N (range 3 of the apparatus). The test wheel used is the provided steel disc. The hardness tester is placed perpendicularly onto the surface to be tested and is pressed down so that the guide wheels touch the surface. In this way the preset force acting upon the test disc is fully effective on the test surface. The instrument is then moved, the wheel being over the specimen to be tested. - The scratch resistance is related to maximum force at which the test body does not leave any trace on the test surface. The results are presented in Table 3 in a comparative manner compared to a typical requirement "+" slightly above requirement, "++" significantly above requirement.
Table 3: Scratch resistance of the sheets Alloy scratch resistance A + B + C ++ - With the composition according to the invention, an improved scratch resistance is obtained, without degrading elongation before or after the curing.
Claims (11)
- Sheet made of an aluminium alloy comprising, by weight %Mg : 0.8 - 1.3,Mn : 0.8 - 1.2,Cu: 0.05 - 0.30,Cr : 0.05 - 0.30,Fe : ≤ 0.4,Si : ≤ 0.3,Zn : ≤ 0.25,Ti : ≤ 0.15,impurities < 0.05 each and < 0.15 total, remainder aluminium.
- Sheet according to claim 1 comprising by wt. % Cr : 0.10 - 0.30 and preferably Cr : 0.15 - 0.25.
- Sheet according to claim 1 or claim 2 comprising, by wt.%, Fe : 0.15 - 0.35 and/or Si : 0.10 - 0.25.
- Sheet according to anyone of claims 1 to 3 comprising, by wt.%, Mg : 0,9 - 1.1.
- Sheet according to anyone of claims 1 to 4 comprising, by wt.%, Mn : 0.85 - 1.15 and preferably Mn : 0.95 - 1.05.
- Sheet according to anyone of claims 1 to 5 comprising, by wt.%, Cu : 0.10 - 0.25 and preferably Cu : 0.15 - 0.20.
- Sheet according to anyone of claims 1 to 6 wherein TYS in the longitudinal direction is at least 130 MPa and A% in the longitudinal direction is at least 16%.
- Sheet according to anyone of claims 1 to 7 wherein, after a thermal treatment of 4 min at 195 °C TYS in the longitudinal direction is at least 110 MPa and A% in the longitudinal direction is at least 16%.
- Method to make a sheet according to anyone of claims 1 to 8 wherein,(a) a slab is cast of an aluminium alloy comprising, by weight %Mg : 0.8 - 1.3,Mn : 0.8 - 1.2,Cu: 0.05 - 0.30,Cr : 0.05 - 0.30,Fe : ≤ 0.4,Si : ≤ 0.3,Zn : ≤ 0.25,Ti : ≤ 0.15,impurities < 0.05 each and < 0.15 total, remainder aluminium,(b) the slab is homogenized at a temperature of at least 550 °C,(c) the homogenized slab is hot rolled to an intermediate rolled product having a thickness from 3 to 10 mm,(d) the intermediate rolled product is cold rolled into a sheet, optionally with an intermediate annealing during cold rolling,(e) the sheet is annealed at a temperature from 300°C to 400 °C and undergoes tension leveling with a stretching of at least 1%.
- Use of a sheet according to anyone of claims 1 to 9 to make a coated decorative part preferably a decorative part for an automobile, or a household appliance or a medical device.
- Use according to claim 10 to make an automobile interior finishing element selected in the list consisting of a door handle, a gearbox trim, a trim element for a center console, a trim for a dashboard, a panel for a dashboard, a trim for a door, a panel for a door and a capacitive function element or an automobile exterior element selected in the list consisting of a window surrounds, a body side or door trim strip, a tailgate trim strip, a radiator grille trim, wheel hub cover, a beltline and a bumper piping.
Priority Applications (8)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP21159556.6A EP4050115A1 (en) | 2021-02-26 | 2021-02-26 | Durable aluminium alloy sheet for decorative applications |
PCT/EP2022/053220 WO2022179856A1 (en) | 2021-02-26 | 2022-02-10 | Durable aluminium alloy sheet for decorative applications |
KR1020237032761A KR20230150991A (en) | 2021-02-26 | 2022-02-10 | Durable aluminum alloy sheet for decorative applications |
CN202280012840.2A CN116848276A (en) | 2021-02-26 | 2022-02-10 | Durable aluminum alloy sheet for decorative applications |
EP22704766.9A EP4298258A1 (en) | 2021-02-26 | 2022-02-10 | Durable aluminium alloy sheet for decorative applications |
CA3206313A CA3206313A1 (en) | 2021-02-26 | 2022-02-10 | Durable aluminium alloy sheet for decorative applications |
US18/547,214 US20240229197A9 (en) | 2021-02-26 | 2022-02-10 | Durable aluminium alloy sheet for decorative applications |
JP2023551960A JP2024507392A (en) | 2021-02-26 | 2022-02-10 | Durable aluminum alloy sheet for decorative applications |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
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EP21159556.6A EP4050115A1 (en) | 2021-02-26 | 2021-02-26 | Durable aluminium alloy sheet for decorative applications |
Publications (1)
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EP4050115A1 true EP4050115A1 (en) | 2022-08-31 |
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Family Applications (2)
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EP21159556.6A Withdrawn EP4050115A1 (en) | 2021-02-26 | 2021-02-26 | Durable aluminium alloy sheet for decorative applications |
EP22704766.9A Pending EP4298258A1 (en) | 2021-02-26 | 2022-02-10 | Durable aluminium alloy sheet for decorative applications |
Family Applications After (1)
Application Number | Title | Priority Date | Filing Date |
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EP22704766.9A Pending EP4298258A1 (en) | 2021-02-26 | 2022-02-10 | Durable aluminium alloy sheet for decorative applications |
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EP (2) | EP4050115A1 (en) |
JP (1) | JP2024507392A (en) |
KR (1) | KR20230150991A (en) |
CN (1) | CN116848276A (en) |
CA (1) | CA3206313A1 (en) |
WO (1) | WO2022179856A1 (en) |
Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0504077A1 (en) | 1991-03-14 | 1992-09-16 | Pechiney Rhenalu | Strong, formable, isotropic aluminium alloys for deep drawing |
CN102703776A (en) * | 2012-06-08 | 2012-10-03 | 中铝瑞闽铝板带有限公司 | Aluminum alloy substrate for light-emitting diode (LED) television and production method for aluminum alloy substrate |
WO2014203077A1 (en) | 2013-06-17 | 2014-12-24 | Constellium Singen Gmbh | Motor vehicle moulding ring made from aluminium/magnesium alloy |
WO2015140833A1 (en) | 2014-03-20 | 2015-09-24 | 株式会社Uacj | Aluminum alloy sheet for dr can body and manufacturing method therefor |
WO2016039215A1 (en) * | 2014-09-10 | 2016-03-17 | 株式会社神戸製鋼所 | Aluminum alloy sheet for can body |
WO2016100800A1 (en) | 2014-12-19 | 2016-06-23 | Novelis Inc. | Aluminum alloy suitable for the high speed production of aluminum bottle and the process of manufacturing thereof |
WO2016149061A1 (en) | 2015-03-13 | 2016-09-22 | Novelis Inc. | Aluminum alloys for highly shaped packaging products and methods of making the same |
CN108330417A (en) * | 2018-02-12 | 2018-07-27 | 西南铝业(集团)有限责任公司 | A kind of aluminum alloy plate materials board-shape control method |
WO2018143376A1 (en) | 2017-02-01 | 2018-08-09 | 株式会社Uacj | Aluminum alloy sheet and production method therefor |
-
2021
- 2021-02-26 EP EP21159556.6A patent/EP4050115A1/en not_active Withdrawn
-
2022
- 2022-02-10 KR KR1020237032761A patent/KR20230150991A/en unknown
- 2022-02-10 WO PCT/EP2022/053220 patent/WO2022179856A1/en active Application Filing
- 2022-02-10 CN CN202280012840.2A patent/CN116848276A/en active Pending
- 2022-02-10 EP EP22704766.9A patent/EP4298258A1/en active Pending
- 2022-02-10 JP JP2023551960A patent/JP2024507392A/en active Pending
- 2022-02-10 CA CA3206313A patent/CA3206313A1/en active Pending
Patent Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0504077A1 (en) | 1991-03-14 | 1992-09-16 | Pechiney Rhenalu | Strong, formable, isotropic aluminium alloys for deep drawing |
CN102703776A (en) * | 2012-06-08 | 2012-10-03 | 中铝瑞闽铝板带有限公司 | Aluminum alloy substrate for light-emitting diode (LED) television and production method for aluminum alloy substrate |
WO2014203077A1 (en) | 2013-06-17 | 2014-12-24 | Constellium Singen Gmbh | Motor vehicle moulding ring made from aluminium/magnesium alloy |
WO2015140833A1 (en) | 2014-03-20 | 2015-09-24 | 株式会社Uacj | Aluminum alloy sheet for dr can body and manufacturing method therefor |
WO2016039215A1 (en) * | 2014-09-10 | 2016-03-17 | 株式会社神戸製鋼所 | Aluminum alloy sheet for can body |
WO2016100800A1 (en) | 2014-12-19 | 2016-06-23 | Novelis Inc. | Aluminum alloy suitable for the high speed production of aluminum bottle and the process of manufacturing thereof |
WO2016149061A1 (en) | 2015-03-13 | 2016-09-22 | Novelis Inc. | Aluminum alloys for highly shaped packaging products and methods of making the same |
WO2018143376A1 (en) | 2017-02-01 | 2018-08-09 | 株式会社Uacj | Aluminum alloy sheet and production method therefor |
CN108330417A (en) * | 2018-02-12 | 2018-07-27 | 西南铝业(集团)有限责任公司 | A kind of aluminum alloy plate materials board-shape control method |
Also Published As
Publication number | Publication date |
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EP4298258A1 (en) | 2024-01-03 |
CA3206313A1 (en) | 2022-09-01 |
US20240133002A1 (en) | 2024-04-25 |
JP2024507392A (en) | 2024-02-19 |
KR20230150991A (en) | 2023-10-31 |
CN116848276A (en) | 2023-10-03 |
WO2022179856A1 (en) | 2022-09-01 |
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