Aluminium alloy, suitable for the incorporation of post-consumer waste, and containers obtained made of said aluminium alloy

Abstract

The invention relates to an aluminium alloy composed of, in % by weight: 0.05% to 0.6% silicon, 0.05% to 0.6% iron; 0.05% to 1.0% manganese; 0.001% to 0.5% barium; 0.001% to 0.5% strontium; 0.001% to 0.15% titanium; up to 1.0% copper; up to 0.4% magnesium; up to 0.15% chromium; up to 0.15% zinc; up to 0.15% vanadium; up to 0.20% zirconium; the other elements being up to 0.05% each and 0.15% in total, the remainder being aluminium. The invention also relates to a manufacturing process and products, in particular wrought products, comprising the alloy according to the invention, in particular a container body, intended to receive a pressurised or non-pressurised content.

Description

[0001] DESCRIPTION

[0002] Title: Aluminum alloy, suitable for the incorporation of post-consumer waste, and containers obtained from said aluminum alloy

[0003] Field of invention

[0004] The present invention relates generally to alloys, including those made from recycled materials and particularly used in the manufacture of aluminum containers. The invention particularly relates to containers obtained by a process known as impact extrusion. More specifically, the present invention relates to methods and alloy compositions used in the manufacture of pins used to make containers, and other articles, by impact extrusion.

[0005] Prior art

[0006] Aluminum recycling has the advantage of being economical and environmentally friendly. The production of secondary aluminum requires up to 95% less energy than primary aluminum and allows for the reduction of CO2 emissions. In an effort to improve the environmental impact of aluminum production, the aluminum industry seeks to maximize the rate of recycled material in products. However, increasing the rate of recycled material generally leads to an increase in the impurity content, particularly the iron content, involving higher volume fractions and / or sizes and / or a more heterogeneous spatial distribution of iron-containing intermetallic particles that can be detrimental, in particular, to process times such as homogenization, to forming properties such as elongation and formability, and to surface properties such as response to anodization.This difficulty is explained, for example, in the article "Texture control by thermomechanical processing of AA6xxx Al-Mg-Si sheet alloys for automotive applications—a review" in the journal Materials Science and Engineering A336 (2002) 249-262.

[0007] In order to avoid this harmful effect, it may be considered to purify the metal.

[0008] Patent FR2902800 describes a process for manufacturing a remelting block from scrap, making it possible in particular to purify iron and silicon from scrap alloys of the 2XXX series or the 7XXX series, without however eliminating additional elements such as zinc, copper and magnesium.

[0009] However, these additional purification steps can be difficult to implement and expensive. Patent application WO2015 / 151907 A1 also mentions the problem of impurity content in recycled alloys.

[0010] Patent application US20080175747 describes an alloy in which impurities have little effect on the properties.

[0011] Patent application JP2007169740 A discloses an alloy comprising, in wt%, Si: 0.5 - 1.5%, Mg: 0.2 - 2.0%, and up to Fe: 1.5%, up to Mn: 1.0%, up to Cr: 0.5%, up to Zr: 0.5%, up to V: 0.3%, up to Ti: 0.2%, up to Zn: 1.5%, up to Cu: 1.0% and containing not less than 0.015% and not more than 0.5% of Bi, Sn, Ga, Co, Ni, Ca, Mo, Be, Pb, and W remaining aluminum and impurities.

[0012] Patent application JP2016037632 discloses an aluminum alloy sheet containing Mg: 0.2-2.0 mass%, Si: 0.3-2.0 mass% and Fe: 0.01-0.5 mass% and one or both of Ni and Co totaling 0.002-0.3 mass% and the balance Al with unavoidable impurities.

[0013] The question of recycling is particularly relevant for aluminium containers, such as packaging, and in particular containers which can be obtained by stamping and possibly drawing of sheets or by impact extrusion of pins possibly followed by drawing.

[0014] Impact extrusion, also known as impact extrusion, possibly followed by drawing, is a process used to manufacture metal container bodies and other articles with unusual shapes. These products are generally made from an alloy slug composed of iron, magnesium, copper, aluminum, tin, or lead. The container body is formed within the containment die from a lubricated slug that is impacted by a punch. The force of the punch deforms the slug around the punch to form the inner surface and along the die to form the outer surface. Once the initial shape is formed, the container body is removed from the punch with a counterpunch ejector, and other swaging and forming tools are used to form it into a desired shape.Impact-formed container bodies are intended to accommodate pressurized or non-pressurized contents; they include aerosol dispensers, battery cases, and other containers, particularly those requiring high strength and thus utilizing a thicker wall than traditional aluminum beverage containers.

[0015] In a conventional impact extrusion process, near-pure aluminum is used due to its unique physical characteristics, typically AA1070 or AA1050 alloys, as designated by The Aluminum Association, consisting of at least about 99.5% pure aluminum. Due to the strength requirements of these containers and the lxxx family alloys generally used, the cost of these containers can be significant compared to conventional beverage containers which generally use AA3104 alloy.

[0016] Patent application US20130068352 relates to aluminum alloys for use in an impact extrusion manufacturing process to create shaped containers and other manufactured articles. In one embodiment, mixtures of recycled aluminum scrap are used in conjunction with relatively pure aluminum to create new compositions that can be formed and shaped in an environmentally friendly process.

[0017] Patent application US2021340648 relates to an aluminum alloy comprising 0.07 wt% to 0.17 wt% silicon, 0.25 wt% to 0.45 wt% iron, 0.05 wt% to 0.20 wt% copper, 0.30 wt% to 0.50 wt% manganese, 0.05 wt% to 0.25 wt% magnesium, 0.01 wt% to 0.04 wt% titanium, and the balance being aluminum and, optionally, additional constituents.

[0018] Patent application US2021348254 relates to an aluminum alloy comprising: 0.07 wt% to 0.17 wt% silicon, 0.25 wt% to 0.45 wt% iron, 0.02 wt% to 0.15 wt% copper, 0.30 wt% to 0.50 wt% manganese, 0.05 wt% to 0.20 wt% chromium, 0.01 wt% to 0.04 wt% titanium, and the balance aluminum and, optionally, additional constituents.

[0019] Patent application EP3940099 relates to aluminum alloys for the manufacture of impact-extruded aluminum containers, consisting of 0.050-0.265 wt. % Si, 0.150-0.250 wt. % Fe, 0.010-0.125 wt. % Cu, 0.010-0.400 wt. % Mn, 0.100-0.200 wt. % Mg, 0.150-0.250 wt. % Cr, 0.010-0.100 wt. % Ti, 0.001-0.050 wt. % B, less than 0.15 wt. % secondary alloying elements with less than 0.05 wt. % of any secondary alloying element, and aluminum as the remainder.

[0020] Patent application EP3940100 relates to aluminum alloys for the manufacture of aluminum cans by impact extrusion. The alloys according to the invention consist of 0.050-0.200 wt. % Si, 0.150-0.250 wt. % Fe, 0.300-0.800 wt. % Cu, 0.010-0.400 wt. % Mn, 0.050-0.200 wt. % Mg, 0.003-0.050 wt. % Cr, 0.010-0.100 wt. % Ti, 0.001-0.050 wt. % B, less than 0.15 wt. % secondary alloying elements with less than 0.05 wt. % of any secondary alloying element, and aluminum as the remainder. Patent application EP4130306 relates to a process for producing an alloy strip from recycled aluminium in which up to 100% post-consumer aluminium can be used as secondary aluminium, whereby a CO2 saving of at least 89% compared to the use of primary aluminium is achieved, and thus a significant contribution to sustainability can be made.

[0021] The article "Making sustainable aluminum by recycling scrap: The science of "dirty alloy"", Raabe Dierk et al. Progress in Materials Science, Pergamon press, GB, vol. 128, April 7, 2022, describes the design and production of aluminum alloys with the highest possible scrap fractions, using even low-grade scrap and scrap types that only correspond to a few target alloys once recycled. This document mentions on page 75, paragraph 3 that chemical modifiers Na, Sr, Ca, Ba, and Eu are usually added to melts of recycled Al-Si alloys to eliminate the harmful effects of Si.

[0022] The problem that the present invention seeks to solve is therefore to provide an alloy, in particular a 3XXX series Al-Mn alloy or an 8XXX series Al-Fe alloy, which can tolerate an increased content of impurities, in particular iron, and therefore does not require additional purification to manufacture wrought products. The problem is in particular to find a light but strong aluminum alloy for forming impact-extruded container bodies and other useful articles, and to use aluminum scrap to benefit the environment and save valuable natural resources. A problem that the present invention solves is to find an alloy having an improved compromise between recycled content, formability, in particular of impact-extruded slugs, and final mechanical properties, in particular of impact-extruded container bodies.

[0023] Summary of the invention

[0024] An object of the invention is an aluminum alloy composed, in % by weight, of:

[0025] 0.05% to 0.6% silicon,

[0026] 0.05% to 0.6% iron,

[0027] 0.05% to 1.0% manganese,

[0028] 0.001% to 0.5% barium,

[0029] 0.001% to 0.5% strontium,

[0030] 0.001 to 0.15% titanium, up to 1.0% copper, up to 0.4% magnesium, up to 0.15% chromium, up to 0.15% zinc, up to 0.15% vanadium, up to 0.20% zirconium, other elements up to 0.05% each and 0.15% in total, the remainder being aluminum.

[0031] Another subject of the invention is a method for manufacturing a wrought product comprising the steps: a) Providing aluminum, chosen from a metal resulting from electrolysis and / or pre-consumer manufacturing scraps and / or post-consumer waste having optionally been melted separately and possibly solidified and addition elements in suitable form, b) if necessary melting the aluminum, to obtain a liquid aluminum bath, c) Adjusting the composition of the liquid aluminum bath using the addition elements to obtain an alloy according to the invention, with the possible exception of the Ti content, d) casting the alloy by adding a refining agent containing at least TiC, to obtain a raw form whose composition is an alloy according to the invention, e) hot and optionally cold working the raw form.

[0032] Another subject of the invention is a method of manufacturing a container body comprising the steps of, starting from a slug whose composition is made of an alloy according to the invention or starting from a slug resulting from a method according to the invention: i) shaping the slug into an unfinished container body by impact extrusion, optionally followed by drawing, ii) cutting the unfinished container body to length.

[0033] Another subject of the invention is a method of manufacturing a container, comprising the steps of: a) producing a container body by a method according to the invention,

[0034] P) transforming the container body into a container, possibly by forming it in diameter and / or by attaching a closure piece to said container body.

[0035] Another subject of the invention is a wrought product comprising or consisting of an alloy according to the invention or capable of being obtained by a process according to the invention.

[0036] Another subject of the invention is a semi-finished product, preferably a pin or a container body, comprising or made of an aluminum alloy according to the invention or capable of being obtained by a method according to the invention. Another subject of the invention is a finished product consisting of a container, preferably a package, for example an aerosol generator or a protective sleeve, intended to receive pressurized or non-pressurized contents, which container comprises a container body according to the invention, on which a closure part is optionally attached.

[0037] Another object of the invention is the use of an aluminum alloy according to the invention for the production of a pin or a container body.

[0038] Detailed description

[0039] Various other features of the invention will emerge from the attached description, in combination with the drawings which illustrate:

[0040] [Fig. 1] is an optical microscopy view of alloy A,

[0041] [Fig. 2] is an optical microscopy view of alloy B,

[0042] [Fig. 3] is an optical microscopy view of alloy C,

[0043] [Fig. 4] is an optical microscopy view of alloy D,

[0044] [Fig. 5] is an optical microscopy view of alloy E,

[0045] [Fig. 6] is a schematic view of a pawn and various container bodies and containers derived from said pawn.

[0046] Unless otherwise stated, all information regarding the chemical composition of alloys is expressed as a percentage by weight relative to the total weight of the alloy. The expression 1.4 Cu means that the copper content expressed as a percentage by weight is multiplied by 1.4. The designation of alloys is made in accordance with the regulations of the Aluminium Association, known to the person skilled in the art.

[0047] The static mechanical properties in tension, i.e. the breaking load Rm, the conventional yield strength at 0.2% elongation Rp0.2 (tensile yield strength), and the elongation at break A%, are determined by a tensile test according to standard NF EN ISO 6892-1. Unless otherwise stated, the definitions in standard EN 12258 (2012) apply.

[0048] Unless otherwise stated, the metallurgical conditions defined in standard EN 515 (2017) apply.

[0049] The inventors have identified an aluminum alloy composition and a method for manufacturing wrought products made from this aluminum alloy, making it possible to solve the problem posed. The alloy is distinguished in particular by the addition of a combination of barium and strontium in association with silicon, iron, manganese, and titanium and optionally with copper, magnesium, chromium, zinc, vanadium and zirconium. The method for manufacturing the alloy products according to the invention is also distinguished by the addition of a refining agent containing TiC during casting.

[0050] The alloy according to the invention contains at least 0.05% and at most 0.6% by weight of silicon. Advantageously, the silicon content is from 0.08% to 0.5% by weight and preferably from 0.10% to 0.40% by weight. In one embodiment, the Si content is at least 0.08%, or is at least 0.11%, or is at least 0.14%, or is at least 0.17%, or is at least 0.20%, or is at least 0.23%, or is at least 0.27%, or is at least 0.30%. In one embodiment, the Si content is at most 0.60%, or is at most 0.57%, or is at most 0.54%, or is at most 0.51%, or is at most 0.48%, or is at most 0.45%.

[0051] The alloy according to the invention contains at least 0.05% and at most 0.6% by weight of iron. Advantageously, the iron content is from 0.25% to 0.55% by weight and preferably from 0.30% to 0.50% by weight. In one embodiment, the iron content is from 0.08% to 0.5% by weight, preferably from 0.1% to 0.40% by weight. In one embodiment, the Fe content is at least 0.08%, or is at least 0.11%, or is at least 0.14%, or is at least 0.17%, or is at least 0.20%, or is at least 0.23%, or is at least 0.26%, or is at least 0.29%, or is at least 0.32%, or is at least 0.35%, or is at least 0.38%. In one embodiment, the Fe content is at most 0.60%, or is at most 0.57%, or is at most 0.54%, or is at most 0.51%, or is at most 0.48%, or is at most 0.45%.

[0052] The alloy according to the invention contains at least 0.05% and at most 1.0% by weight of manganese.

[0053] Advantageously, the manganese content is 0.1% to 0.6%, preferably 0.3% to 0.5%.

[0054] In one embodiment, the Mn content is at least 0.10%, or is at least 0.15%, or is at least 0.20%, or is at least 0.25%, or is at least 0.30%, or is at least 0.35%. In one embodiment, the Mn content is at most 1.00%, or is at most 0.95%, or is at most 0.90%, or is at most 0.85%, or is at most 0.80%, or is at most 0.75%, or is at most 0.70%, or is at most 0.65%, or is at most 0.60%, or is at most 0.55%, or is at most 0.50%.

[0055] Preferably the Fe and / or Mn contents are higher than those of all other elements.

[0056] In one embodiment, the alloy according to the invention is an Al-Mn alloy of the 3XXX series, i.e. the main alloying element is Mn, or an Al-Fe alloy of the 8XXX series, i.e. the main alloying element is Fe, it being understood in both cases that the aluminum content is less than 99.00%. In another embodiment, the alloy according to the invention is an alloy of the 1XXX series, the aluminum content of which is at least 99.00%.

[0057] The alloy according to the invention contains at least 0.001% and at most 0.5% by weight of barium. Advantageously, the barium content is from 0.005% to 0.3%, preferably from 0.008% to 0.05%.

[0058] In one embodiment, the Ba content is at least 0.002%, or is at least 0.004%, or is at least 0.006%, or is at least 0.008%, or is at least 0.010%, or is at least 0.012%, or is at least 0.014%, or is at least 0.016%, or is at least 0.018%. In one embodiment, the Ba content is at most 0.50%, or is at most 0.45%, or is at most 0.40%, or is at most 0.35%, or is at most 0.30%, or is at most 0.25%, or is at most 0.20%, or is at most 0.15%, or is at most 0.10%, or is at most 0.05%. In one embodiment, the Ba content is at most 0.050%, or is at most 0.048%, or is at most 0.046%, or is at most 0.044%, or is at most 0.042%, or is at most 0.040%, or is at most 0.038%, or is at most 0.036%, or is at most 0.034%, or is at most 0.032%, or is at most 0.030%, or is at most 0.028%.

[0059] The alloy according to the invention contains at least 0.001% and at most 0.5% by weight of strontium.

[0060] Advantageously, the strontium content is from 0.005% to 0.3%, preferably from 0.008% to 0.05%.

[0061] In one embodiment, the Sr content is at least 0.002%, or is at least 0.004%, or is at least 0.006%, or is at least 0.008%, or is at least 0.010%, or is at least 0.012%, or is at least 0.014%, or is at least 0.016%, or is at least 0.018%. In one embodiment, the Sr content is at most 0.50%, or is at most 0.45%, or is at most 0.40%, or is at most 0.35%, or is at most 0.30%, or is at most 0.25%, or is at most 0.20%, or is at most 0.15%, or is at most 0.10%, or is at most 0.05%. In one embodiment, the Sr content is at most 0.050%, or is at most 0.048%, or is at most 0.046%, or is at most 0.044%, or is at most 0.042%, or is at most 0.040%, or is at most 0.038%, or is at most 0.036%, or is at most 0.034%, or is at most 0.032%, or is at most 0.030%, or is at most 0.028%.

[0062] As demonstrated in the examples, the combined addition of Ba and Sr in the presence of TiC makes it possible in particular to obtain intermetallic particles containing iron that are finer on average, with a more homogeneous spatial distribution, and a reduced maximum size, compared to an alloy without such a combined addition of Ba / Sr. Thus, for the products according to the invention, the microstructure obtained for an alloy containing a high percentage by weight of iron, typically containing a high proportion of recycled material, can be close to that of an alloy whose iron content is lower, and therefore can make it possible to obtain comparable hardness and formability properties. The alloy according to the invention makes it possible, in particular, to obtain slugs having excellent extrusion ability, linked in particular to improved elongation after heat treatment of the raw slugs, while having high mechanical strength after impact extrusion.In addition, the container bodies obtained after impact extrusion have an improved suitability for expanding or crimping operations, illustrated in particular by the performance in an axial resistance test.

[0063] Generally speaking, "intermetallic particles" means compounds containing several metallic or metalloid elements and having a crystallographic structure different from the crystallographic structure of the solid solution of aluminum, such as Al-Fe, Al-Mn-Fe, Al-Fe-Si, Al-Fe-Mn-Si, or Mg-Si, etc.

[0064] In an advantageous embodiment, the sum of the Ba and Sr contents is from 0.005 to 0.08% by weight and preferably from 0.01 to 0.04% by weight.

[0065] The alloy according to the invention contains at least 0.001% and at most 0.15% by weight of titanium. Advantageously, the titanium content is from 0.01% to 0.05%, preferably from 0.02% to 0.04% by weight.

[0066] In one embodiment, the Ti content is at least 0.002%, or is at least 0.004%, or is at least 0.006%, or is at least 0.008%, or is at least 0.010%, or is at least

[0067] 0.012%, or is at least 0.014%, or is at least 0.016%, or is at least 0.018%. In one embodiment, the Ti content is at most 0.140%, or is at most 0.135%, or is at most 0.130%, or is at most 0.125%, or is at most 0.120%, or is at most 0.115%, or is at most 0.110%, or is at most 0.105%, or is at most 0.100%, or is at most 0.095%, or is at most 0.090%, or is at most 0.085%, or is at most 0.080%, or is at most 0.075%, or is at most 0.070%, or is at most 0.065%, or is at most 0.060%, or is at most 0.055%, or is at most 0.050%, or is at most 0.045%.

[0068] The method of adding titanium is also important. According to the invention, at least part of the titanium is added in the form of a refining agent containing at least TiC, such as AITi3C0.15, a refining agent whose composition is 3% Ti 0.15% C remains AL The carbon content, which is of the order of a few ppm cannot be measured easily and is therefore not indicated in the composition. Typically 0.1 to 2 kg of this refining agent is added per tonne of metal. The rest of the titanium can come from titanium platelet or other refining agents such as AITi3B, AITi5B, AITi5B0.2 or AITi3B0.2.

[0069] The alloy according to the invention may contain at most 1.0% by weight of copper. Advantageously, the copper content is from 0.005% to 0.5%, preferably from 0.01% to 0.2%. In one embodiment, the Cu content is at least 0.001% or is at least 0.005%, or is at least 0.007%, or is at least 0.009%, or is at least 0.011%, or is at least 0.013%, or is at least 0.015%, or is at least 0.017%. In one embodiment, the Cu content is at most 0.95%, or is at most 0.90%, or is at most 0.85%, or is at most 0.80%, or is at most 0.75%, or is at most 0.70%, or is at most 0.65%, or is at most 0.60%, or is at most 0.55%, or is at most 0.50%, or is at most 0.45%, or is at most 0.40%, or is at most 0.35%, or is at most 0.30%, or is at most 0.25%.

[0070] The alloy according to the invention may contain at most 0.4% by weight of magnesium. Advantageously, the magnesium content is up to 0.38%, preferably from 0.05% to 0.35% by weight, preferentially from 0.10% to 0.35%. In one embodiment, the magnesium content is from 0.15% to 0.35%. In one embodiment, the Mg content is at most 0.44%, or is at most 0.42%, or is at most 0.40%, or is at most 0.38%, or is at most 0.36%, or is at most 0.34%, or is at most 0.32%, or is at most 0.30%, or is at most 0.28%, or is at most 0.26%, or is at most 0.24%, or is at most 0.22%.

[0071] The alloy according to the invention may contain at most 0.15% by weight of chromium. In one embodiment, the Cr content is at least 0.01%, or is at least 0.02%, or is at least 0.03%, or is at least 0.04%, or is at least 0.05%, or is at least 0.06%, or is at least 0.07%, or is at least 0.08%, or is at least 0.09%, or is at least 0.10%, or is at least 0.11%, or is at least 0.12%, or is at least 0.13%, and / or is at most 0.14%, or is at most 0.13%, or is at most 0.12%, or is at most 0.11%, or is at most 0.10%, or is at most 0.09%, or is at most 0.08%, or is at most 0.07%, or is at most 0.06%, or is at most 0.05%, or is at most

[0072] 0.04%, or is at most 0.03%, or is at most 0.02%.

[0073] The alloy according to the invention may contain at most 0.15% by weight of vanadium. In one embodiment, the V content is at least 0.01%, or is at least 0.02%, or is at least 0.03%, or is at least 0.04%, or is at least 0.05%, or is at least 0.06%, or is at least 0.07%, or is at least 0.08%, or is at least 0.09%, or is at least 0.10%, or is at least 0.11%, or is at least 0.12%, or is at least 0.13%, and / or is at most 0.14%, or is at most 0.13%, or is at most 0.12%, or is at most 0.11%, or is at most 0.10%, or is at most 0.09%, or is at most 0.08%, or is at most 0.07%, or is at most 0.06%, or is at most 0.05%, or is at most 0.04%, or is at most 0.03%, or is at most 0.02%.

[0074] The alloy according to the invention may contain at most 0.20% by weight of zirconium. In one embodiment, the Zr content is at least 0.01%, or is at least 0.02%, or is at least 0.03%, or is at least 0.04%, or is at least 0.05%, or is at least 0.06%, or is at least 0.07%, or is at least 0.08%, or is at least 0.09%, or is at least 0.10%, or is at least 0.11%, or is at least 0.12%, or is at least 0.13%, or is at least 0.14%, or is at least 0.15%, or is at least 0.16%, or is at least 0.17%, or is at least 0.18%, and / or is at most 0.19%, or is at most 0.18%, or is at most 0.17%, or is at most 0.16%, or is at most 0.15%, or is at most 0.14%, or is at most 0.13%, or is at most 0.12%, or is at most 0.11%, or is at most 0.10%, or is at most 0.09%, or is at most 0.08%, or is at most 0.07%, or is at most 0.06%, or is at most 0.05%, or is at most 0.04%, or is at most 0.03%, or is at most 0.02%.

[0075] The alloy according to the invention may contain at most 0.15% by weight of zinc. In an advantageous embodiment, the zinc content is from 0.01% to 0.05%. In another advantageous embodiment, the zinc content is less than 0.01%. In one embodiment, the Zn content is at least 0.01%, or is at least 0.02%, or is at least 0.03%, or is at least 0.04%, or is at least 0.05%, or is at least 0.06%, or is at least 0.07%, or is at least 0.08%, or is at least 0.09%, or is at least 0.10%, or is at least 0.11%, or is at least 0.12%, or is at least 0.13%, and / or is at most 0.14%, or is at most 0.13%, or is at most 0.12%, or is at most 0.11%, or is at most 0.10%, or is at most 0.09%, or is at most 0.08%, or is at most 0.07%, or is at most 0.06%, or is at most 0.05%, or is at most 0.04%, or is at most 0.03%, or is at most 0.02%.

[0076] The other elements are up to 0.05% each and 0.15% in total, with the remainder being aluminum.

[0077] In one embodiment, the aluminum alloy according to the invention is composed, in % by weight, of:

[0078] 0.15% to 0.45% silicon,

[0079] 0.30% to 0.50% iron,

[0080] 0.25% to 0.55% manganese,

[0081] 0.005% to 0.05% barium,

[0082] 0.005% to 0.05% strontium,

[0083] 0.01 to 0.10% titanium,

[0084] 0.05 to 0.35% magnesium, other elements up to 0.05% each and 0.15% total, the remainder being aluminum.

[0085] In one embodiment, the aluminum alloy is composed, in % by weight, of:

[0086] 0.10% to 0.30% silicon,

[0087] 0.35% to 0.55% iron,

[0088] 0.30% to 0.50% manganese,

[0089] 0.005% to 0.05% barium, 0.005% to 0.05% strontium,

[0090] 0.01 to 0.10% titanium,

[0091] 0.10% to 0.35% magnesium, other elements up to 0.05% each and 0.15% total, the remainder being aluminum.

[0092] The other elements are typically unavoidable impurities or incidental elements such as the carbon already mentioned.

[0093] The alloy according to the invention is particularly useful for obtaining wrought products. A method for manufacturing products according to the invention comprises the steps of: a) Providing aluminum, chosen from a metal resulting from electrolysis (for example in liquid, ingot or sow form), and / or pre-consumer manufacturing scrap, and / or post-consumer waste having optionally been melted separately and possibly solidified (for example in ingot or sow form), or a combination of at least two of them, and addition elements in appropriate form, b) if necessary melting said aluminum, to obtain a liquid aluminum bath, c) Adjusting the composition of the liquid aluminum bath using the addition elements to obtain an alloy according to the invention, with the possible exception of the Ti content, d) casting the alloy by adding a refining agent containing at least TiC,to obtain a raw form whose composition is made of an alloy according to the invention, e) hot and optionally cold working the raw form.,

[0094] In a first step, aluminium from electrolysis and / or pre-consumer manufacturing scrap and / or post-consumer waste, optionally melted separately and possibly solidified, and additional elements in an appropriate form, are supplied.

[0095] Aluminum produced by electrolysis generally has the disadvantage of generating significant CO2 emissions during its manufacture, and we therefore try to limit its use.

[0096] As for other sources of metal, we distinguish:

[0097] - pre-consumer manufacturing scrap, which is generated before the metal is delivered to the end customer, for example the consumer of packaged goods, the user of an electric vehicle, and

[0098] - post-consumer waste, which is recovered after the product has been used, typically from used packaging. Such sources of metal are further defined in ISO 14021 (Second Edition 2016-03-15 - Environmental marking and declarations - Self-declared environmental declarations (Type II labelling)).

[0099] The manufacturing stages of aluminum products generate numerous pre-consumer manufacturing scraps during all stages. These may include, for example, the ends of cast plates or billets that have been dropped before hot working, the ends of rolled or extruded products that have been dropped during the manufacturing process of rolled or extruded products, skeletons of blanks used for stamping, skeletons of pins used for impact extrusion, machining chips, etc. Post-consumer waste includes, for example, used packaging, used profiles from window frames or windows recovered during building demolitions, automobile parts recovered from scrap yards, crushed automobiles, dismantled aircraft, aluminum wires, lithographic plates, etc.Post-consumer waste can be supplied raw, in compacted form, or optionally after being melted separately and eventually solidified. Additional elements are also supplied in appropriate forms. These can be elements in their metallic form or in an alloyed form.

[0100] The method according to the invention is advantageous because it allows the use of a high percentage of manufacturing scraps and / or post-consumer waste. Thus, in one embodiment, the feedstock contains at least 40% or at least 50% or at least 60% or at least 70% or at least 80% or at least 90%, or at least 95%, or at least 98% of manufacturing scraps. Thus, in one embodiment, the feedstock contains at least 40% or at least 50% or at least 60% or at least 70% or at least 80% or at least 90%, or at least 95%, or at least 98% of post-consumer waste. Thus in one embodiment the load contains at least 40% or at least 50% or at least 60% or at least 70% or at least 80% or at least 90%, or at least 95%, or at least 98% of manufacturing scraps and post-consumer waste.

[0101] In one embodiment, a mixture of post-consumer waste from different sources is used: used beverage cans, typically made of 3XXX alloy, and used profiles, typically made of 6XXX alloy. Preferably, in this embodiment, the two sources are used in similar proportions, between 40% and 60% each.

[0102] If necessary, the aluminum is melted to obtain a bath of liquid metal.

[0103] The composition of the liquid aluminum bath is then adjusted using the addition elements to obtain an alloy according to the invention, with the possible exception of the Ti content. By addition elements is meant elements that it is necessary to add during step c) so that the composition of the liquid aluminum bath obtained at the end of step b) is modified if necessary so that at the end of step c) a liquid aluminum bath is obtained in an alloy according to the invention with the possible exception of the Ti content. By appropriate form of the addition elements is meant that their composition, pure or alloyed, and their format, briquette or wafers or powder or wire, makes it possible to carry out step c).

[0104] The alloy is then cast to a rough form, adding a refining agent containing at least TiC such as AITi3C0.15, a refining agent whose composition is 3% Ti 0.15% C remainder Al. Typically 0.1 to 2 kg of this refining agent is added per tonne of metal. The remainder of the titanium can come from titanium platelet or other refining agents such as AITi3B, AITi5B, AITi5B0.2 or AITi3B0.2.

[0105] The raw form is then hot worked and optionally cold worked.

[0106] Advantageously, the rolling is rolling or spinning and / or forging.

[0107] In one embodiment, in the manufacturing method according to the invention, the wrought product is a slug 1 (such a slug is for example illustrated in detail A. of figure 6), the casting of step d) is a continuous casting, typically on a wheel and in step e) the hot working is a hot rolling into a strip which is then cold rolled, and the method further comprises the following steps f) Producing a raw slug from the cold rolled strip, g) Heat treating the raw slug, h) Cooling the heat-treated raw slug, i) treating the surface of the thus cooled raw slug to obtain the slug 1.

[0108] In this embodiment, cooling between the hot rolling and cold rolling stages may be performed in-line, typically by immersion in a cooling liquid such as water, or the hot rolled strip may be coiled and air cooled.

[0109] The invention also relates to a method for manufacturing a container body comprising the steps consisting of, starting from a pin 1 whose composition is made of an alloy according to the invention or resulting from the method according to the invention: j) shaping the pin 1 into an unfinished container body 2 by impact extrusion (also called "impact extrusion" in English), optionally followed by drawing (also called "impact extrusion and ironing" in English), k) cutting the unfinished container body 2 to length (illustrated schematically in detail B. of figure 6).

[0110] Such an impact extrusion method, with optional drawing, is for example described in the document “Shaping Aluminum: Extrusion or Drawing”, Engineering Technique, Roger DEVELAY, M651.

[0111] The shaping of the pin 1 generates an unfinished container body 2 which is a single-piece metal part, advantageously comprising a bottom wall 31 extended by a side wall 32 (preferably tubular).

[0112] Cutting to length advantageously consists of cutting to length the side wall32, also called “trimming”.

[0113] The unfinished container body 2 is also called a “preform”.

[0114] The invention also relates to a method of manufacturing a container comprising the steps of: a) producing a container body 3 by the method according to the invention,

[0115] P) transforming the container body 3 into a container 4, possibly by forming it in diameter and / or by attaching a closure piece to said container body 3.

[0116] The diameter forming consists, for example, in a conventional manner in itself, of a step of shrinking the side wall 32, to form a shoulder 33 (see details C. and D. in figure 6).

[0117] The transformation of the container body 3 may also include:

[0118] - a step of forming a final roll 34, at the free edge of the side wall 32 (see detail C. in figure 6), and / or

[0119] - a step of forming a thread 35 at the level of a neck, intended to receive a threaded capsule (see detail D. in figure 6).

[0120] These transformation steps may include expanding or crimping steps of the closure parts.

[0121] Advantageously, a step of interior varnishing, exterior lacquering and baking of these coatings can be introduced between steps a and .

[0122] The invention also relates to a wrought product comprising or consisting of an alloy according to the invention, or capable of being obtained by the method according to the invention. The invention also relates to a semi-finished product, preferably a pin 1 or a container body 3, comprising or consisting of an aluminum alloy according to the invention or obtained by the method according to the invention.

[0123] By “pawn” is meant in particular a metal part intended to be shaped to obtain a body containing 3.

[0124] Advantageously, the alloy according to the invention allows the manufacture of a container body 3 from a pin 1 whose weight is lower compared to a pin manufactured from an alloy devoid of Ba and Sr.

[0125] For example, the alloy according to the invention allows a weight saving of 5 to 15%.

[0126] Without being limited by any theory, this weight saving is conferred by an improvement in the static mechanical properties in tension of the alloy (i.e. the breaking load Rm and / or the elastic limit Rp0.2

[0127] Advantageously, the semi-finished product according to the invention consists of a container body 3, intended to receive (or contain) a content under pressure (for example a pressure range greater than 0 bar up to 25 bar) or not under pressure / without pressure.

[0128] The container body 3 preferably comprises a bottom wall 31 extended by a side wall 32, advantageously tubular (for example with a circular or prismatic section).

[0129] The invention also relates to a finished product consisting of a container 4, preferably a package, for example:

[0130] - a protective sleeve, for example for battery cells (see detail B. of figure 6),

[0131] - an aerosol generator (see detail C. of figure 6),

[0132] - a metal bottle (see detail D. of figure 6), intended to receive contents under pressure or not under pressure.

[0133] The container 4 comprises a container body 3 according to the invention:

[0134] - open, without a sealing part, or

[0135] - closed, on which a closure piece 36 is possibly attached.

[0136] The closure piece 36 consists for example of a valve as in Figure 6 detail C., a threaded cap as in Figure 6 detail D., an easy-opening cover, a ring with peelable membrane, a capsule or any other form of closure piece.

[0137] The closure part advantageously comprises a metal ring which is sealed on the container body 3 by a conventional crimping technique. In accordance with the present invention, the container body 3 according to the invention comprises finer intermetallic particles on average, with a more homogeneous spatial distribution and a reduced maximum size.

[0138] Without being limited by any theory, the characteristics of the intermetallic particles ensure in particular an improvement in the formability of the container body 3 which improves its surface condition (smoother) and which optimizes its crimping / its sealing with the closure part 36 (in particular when it is attached by crimping).

[0139] Examples

[0140] Example 1

[0141] In this example, various alloys, the composition of which is given in Table 1, were cast in the form of ingots with a minimum section of 17x40 mm.

[0142] [Table 1]

[0143] Alloy A simulates a composition of impact-formed pin 1 in which a high content of recycled material has been incorporated. Alloys B, C, D and E have a composition close to that of alloy A and in which additions of Sr (alloys B and E) and Ba (alloys C and E) have been made. For alloys D and E 1 kg of AITi3C0.15 was added per tonne of metal.

[0144] The casting structure of the alloys was observed by optical microscopy.

[0145] Alloy A has a microstructure, illustrated in Figure 1, in which coarse intermetallics are present.

[0146] In alloys B, C and D, the microstructure shown in Figures 2, 3 and 4, respectively, shows a weak tendency for the maximum intermetallic particle size to be smaller.

[0147] In alloy E, the microstructure, shown in Figure 5, has finer intermetallics on average and the maximum intermetallic particle size is also smaller. To simulate the manufacturing range of impact extrusion slugs, the ingots were machined to a thickness of 15 mm, hot rolled in 3 passes from 15 mm to 8.85 mm, cold rolled to a thickness of 5.85 mm. A final heat treatment of 4 hours at 505 °C was then carried out.

[0148] The mechanical properties obtained after this treatment are given in Table 2. The Brinell hardnesses are characterized under the conditions 2.5 mm / 15.625 KgF. It can be noted that the elongation of example E is greater than that of all the other examples.

[0149] [Table 2]

[0150] Example 2

[0151] In this example, ingots with a section of 190 x 70 mm were cast by direct cooling semi-continuous casting (DC casting), the composition of which is given in Table 3.

[0152] [Table 3]

[0153] After casting, the ingots were reheated, hot rolled to a thickness of 9.1 mm and then cold rolled to a thickness of 6 mm. 49.74 mm diameter impact extrusion pins were cut. The pins were heat treated for 1 h 20 min at 505 °C. For alloys H and I, 1 kg of AITi3C0.15 was added per tonne of metal.

[0154] The mechanical characteristics of the heat-treated pins are given in Table 4. [Table 4]

[0155] The pins were spun by impact extrusion. The mechanical characteristics of the container body after extrusion and of the container after extrusion and final operations, including interior varnishing and exterior lacquering and baking of these coatings, were characterized. The results are given in Table 5.

[0156] [Table 5]

[0157] The examples according to the invention (H and I) have better spinning ability than the reference example G, linked in particular to improved elongation after heat treatment at 505°C, as illustrated in Table 4, while having high mechanical strength after impact spinning (improved RpO.2 and very close Rm), as illustrated in Table 5.

[0158] Example 3

[0159] In this example, aluminium alloys, the composition of which is given in Table 6, were wheel cast and hot and cold rolled to a thickness of 5.05 mm. Alloy K has a composition according to the invention.

[0160] [Table 6]

[0161] Impact extrusion pins with a diameter of 49.74 mm were cut. The pins were heat treated at 430 °C. The mechanical characteristics of the pins thus heat treated are given in Table 7. The pins obtained with the alloy according to the invention present an interesting compromise between elongation and mechanical resistance despite an iron content much higher than that of the reference alloy.

[0162] [Table 7]

[0163] The pins were spun by impact extrusion to obtain container bodies. The mechanical characteristics of the container body after extrusion and of the container after extrusion and final operations, in particular, interior varnishing and exterior lacquering and baking of these coatings were characterized. The results are given in Table 8. The properties of the container body after extrusion and of the container after extrusion and final operations, in particular, interior varnishing and exterior lacquering and baking are satisfactory and advantageous compared to those of the reference alloy J.

[0164] [Table 8]

[0165] An axial resistance test was carried out by exerting an axial compressive force on the container, at positions 33 (shoulder) and 34 (final roll). The results are presented in Table 9.

[0166] [Table 9] This test makes it possible in particular to assess the ability of the container body to resist the expansion or crimping operations of the closure parts (valves or caps).

[0167] Thus, the product manufactured with the alloy according to the invention has an improved suitability for expansion or crimping operations. It should be noted that the mechanical properties of Examples 1, 2 and 3 are not directly comparable because for Example 1, the casting was carried out in the form of a small ingot (17x40 mm) whereas for Example 2, ingots with a section of 190 x 70 mm were cast by direct cooling semi-continuous casting (DC casting) and for Example 3, continuous casting was carried out on a wheel.

Claims

CLAIMS 1. An aluminum alloy composed, in % by weight, of: 0.05% to 0.6% silicon, 0.05% to 0.6% iron, 0.05% to 1.0% manganese, 0.001% to 0.5% barium, 0.001% to 0.5% strontium, 0.001 to 0.15% titanium, up to 1.0% copper, up to 0.4% magnesium, up to 0.15% chromium, up to 0.15% zinc, up to 0.15% vanadium, up to 0.20% zirconium, other elements up to 0.05% each and 0.15% in total, the remainder being aluminum.

2. Aluminum alloy according to claim 1, characterized in that the barium content is 0.005% to 0.3%, preferably 0.008% to 0.05%.

3. Aluminum alloy according to one of the preceding claims, characterized in that the strontium content is from 0.005% to 0.3%, preferably from 0.008% to 0.05%.

4. Aluminum alloy according to one of the preceding claims composed, in % by weight, of: 0.15% to 0.45% silicon, 0.30% to 0.50% iron, 0.25% to 0.55% manganese, 0.005% to 0.05% barium, 0.005% to 0.05% strontium, 0.01 to 0.10% titanium, 0.05 to 0.35% magnesium, other elements up to 0.05% each and 0.15% total, the remainder being aluminum.

5. Aluminum alloy according to one of the preceding claims composed, in % by weight, of: 0.10% to 0.30% silicon, 0.35% to 0.55% iron, 0.30% to 0.50% manganese, 0.005% to 0.05% barium, 0.005% to 0.05% strontium, 0.01 to 0.10% titanium, 0.10% to 0.35% magnesium, other elements up to 0.05% each and 0.15% total, the remainder being aluminum.

6. A method of manufacturing a wrought product comprising the steps: a) Providing aluminum, selected from a metal resulting from electrolysis and / or pre-consumer manufacturing scrap and / or post-consumer waste having optionally been melted separately and possibly solidified and addition elements in suitable form, b) if necessary melting the aluminum, to obtain a liquid aluminum bath, c) Adjusting the composition of the liquid aluminum bath using the addition elements to obtain an alloy according to claims 1 to 5, with the possible exception of the Ti content, d) casting the alloy by adding a refining agent containing at least TiC, to obtain a raw form whose composition is an alloy according to claims 1 to 3, e) hot and optionally cold working the raw form.

7. Method according to claim 6 in which the working is rolling or extrusion and / or forging.

8. A manufacturing method according to claim 6 or claim 7, wherein the wrought product is a slug (1), wherein in step d) the casting is continuous casting, typically on a wheel, in step e) the hot working is hot rolling into a strip which is then cold rolled, and further comprising the following steps: f) Producing a raw slug from the cold rolled strip, g) Heat treating the raw slug, h) Cooling the heat-treated raw pion, i) treating the surface of the cooled raw pion to obtain pion (1).

9. Method for manufacturing a container body (3) comprising the steps of, starting from a pin (1) whose composition is made of an alloy according to claims 1 to 5 or starting from a pin (1) resulting from the method according to claim 8: j) shaping the pin (1) into an unfinished container body (2) by impact extrusion, optionally followed by drawing, k) cutting the unfinished container body (2) to length.

10. A method of manufacturing a container (4), comprising the steps of: a) producing a container body (3) by the method according to claim 9, P) transforming the container body (3) into a container (4), possibly by diameter forming and / or by attaching a closure part (26) to said container body (3).

11. Wrought product comprising or consisting of an alloy according to one of claims 1 to 5 or capable of being obtained by the process according to claim 6 or claim 7.

12. Semi-finished product, preferably a pin (1) or a container body (3), comprising or consisting of an aluminum alloy according to one of claims 1 to 5 or capable of being obtained by the method according to any one of claims 6 to 9.

13. Semi-finished product according to claim 12 characterized in that it consists of a container body (3), intended to receive contents under pressure or not under pressure, which container body (3) preferably comprises a bottom wall (31) extended by a side wall (32).

14. Finished product consisting of a container (4), preferably a package, for example an aerosol generator or a protective sleeve, intended to receive pressurized or non-pressurized contents, which container (4) comprises a container body (3) according to any one of claims 12 or 13, on which a closure part (36) is optionally attached.

15. Use of an aluminum alloy according to any one of claims 1 to 5 for producing a pin (1) or a container body (3).

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