6xxx aluminum alloy with improved recyclability

Abstract

The invention relates to AlMgSi alloys which are particularly favorable for recycling. One subject of the invention is an aluminum-based alloy comprising, in % by weight, Mg: 0.2 – 1.5; Si: 0.3 - 2.0; Fe: 0.25 - 1.0; Ti: 0.01 – 0.15; at least one element selected from Co, Ba, Ni, La, Ce, Ta, Mo, W, Nb, Re, Pr, Nd, Pm, Sm, Y, Ru and Os, the content of the element if selected being from 0.003 to 0.20 and preferably from 0.005 to 0.15; Zr: ≤ 0.15; Mn: ≤ 1.5; V: ≤ 0.20; Zn: ≤ 1.0; Cr: ≤ 0.25; Cu: ≤ 1.5; the balance being aluminum and unavoidable impurities. The addition of certain elements in a small amount makes it possible to modify the size and distribution of the intermetallic particles and thus to tolerate an increased content of impurities, in particular of iron. The invention also relates to a heat-treated wrought product comprising an alloy according to the invention and to a method for manufacturing same. The invention is particularly useful for automotive construction, building construction, aircraft construction or industrial construction.

Description

DESCRIPTION Title: 6XXX ALUMINUM ALLOY WITH IMPROVED RECYCLABILITY TECHNICAL FIELD

[0001] The invention relates to an aluminium alloy of the 6XXX family making it possible to increase the recycling rate in wrought products of this type of alloy, particularly in the automotive sector. PREVIOUS ART

[0002] 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 recycled content of products. However, increasing the recycled content generally leads to an increase in the impurity content, particularly the iron content, involving higher volume fractions and / or sizes of intermetallic particles that can be detrimental, in particular, to process times such as homogenization, forming properties such as elongation and formability, and 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.

[0003] In order to avoid this harmful effect, it may be considered to purify the metal.

[0004] 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.

[0005] However, these additional purification steps can be difficult to implement and expensive.

[0006] Patent application WO2015 / 151907 A1 also mentions the problem of impurity content in recycled alloys.

[0007] Patent application US20080175747 describes an alloy in which impurities have little effect on the properties.

[0008] Patent application J P2007169740 A describes 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: 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.

[0009] 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 remainder Al with unavoidable impurities.

[0010] Patent EP2072628 describes an extruded or forged product made of aluminum alloy of the AIMgSi type comprising, in % by weight: Si 0.5 to 0.95, Mg 0.6 to 0.95, Mn 0.1 to 0.3, V 0.05 to 0.25. , Ni 0.05 to 0.25, Cu maximum 0.3, optionally one or two elements chosen from the group consisting of: (Cr 0.05 to 0.2 and Zr 0.05 to 0.2), Zn < 0.2, Fe < 0.5, Ti < 0.1, unavoidable impurities and remainder in aluminum.

[0011] Patent application CN112342443 relates to an explosion-proof barrier material comprising, in wt%, 0.4-0.8% Si, 0.4-1.0% Fe, 0.2-0.4% Cu, 0.3-0.7% Mn, 0.1-0.25% Zn, 0.1-0.2% Ti, 0.8-1.2% Mg, 0.03-0.4% Cr, 0.05-0.15% Zr, 0.1-0.3% Sc, 0.1-0.3% Ni and the remainder, AL

[0012] US Patent Application 2020 / 095664 relates to high-strength aluminum alloys and methods of manufacturing and processing such alloys.

[0013] Patent application CN106756320 relates to an aluminum alloy rolling rack comprising, in weight percentage, 1.5% to 2.0% of Mg, 1% to 1.4% of Si, 0.2% to 0.5% of Fe, 0.05% to 0.09% of Zn, 0.1% to 0.3% of Cu, 0.2% to 0.4% of Mn, 0.01% to 0.04% of C, 0.2% to 0.4% of B, 0.02% to 0.04% of W, 0.05% to 0.07% of Zr, 0.1% to 0.4% of Cr, 0.05% to 0.09% of Ti, 20% to 35% of aluminum scrap, 0.5% to 1.5% of elements of rare earths and the rest of aluminum.

[0014] The problem that the present invention seeks to solve is therefore to propose an alloy which makes it possible to tolerate an increased content of impurities, in particular iron, and therefore not to require additional purification and also to limit the duration of homogenizations. STATEMENT OF THE INVENTION

[0015] A first subject of the invention is an aluminum-based alloy comprising, in % by weight, - Mg: 0.2 - 1.5; - If: 0.3 - 2.0; - Fe: 0.30 - 1.0; - Ti: 0.01 - 0.15; - at least one element chosen from Co, Ba, Ni, La, Ce, Ta, Mo, W, Nb, Re, Pr, Nd, Pm, Sm, Y, Ru, Os the content of the element if chosen being from 0.003 to 0.20 and preferably from 0.005 to 0.15, - Zr: <0.15; - Mn: <1.5; - V: <0.20; - Zn: <1.0; - Cr: <0.25; - Cu: < 1.5; - remaining aluminum and unavoidable impurities with a content of no more than 0.05% by weight.

[0016] Another subject of the invention is a heat-treated wrought product comprising an alloy according to the invention.

[0017] Yet another subject of the invention is a method of manufacturing a heat-treated wrought product according to the invention comprising the steps of - Supply of pure or alloyed aluminium in the form of primary metal ingots from electrolysis and / or pre-consumer manufacturing scrap and / or post-consumer waste, said waste having optionally been melted separately and possibly solidified and addition elements in appropriate form; - Creation of a charge with the supplied aluminium, melting of this charge and addition of the additive elements to obtain a bath of liquid metal in alloy according to the invention, - Casting, preferably by vertical semi-continuous casting with direct cooling, of said liquid metal bath to obtain a blank suitable for hot working, typically a rolling plate, a forging blank or a billet; - Homogenization of the roughing at a temperature of at least 500°C; - Hot and optionally cold working of the blank by rolling, extrusion and / or forging to obtain a wrought product; - Dissolving the wrought product thus obtained at a temperature of at least 500°C and quenching; - Aging at room temperature and / or tempering of the wrought product put into solution and quenched thus obtained to obtain a heat-treated wrought product. - Yet another object of the invention is the use of a product according to the invention for automobile construction, building construction, aeronautical construction or industrial construction. FIGURES

[0018] Figure 1 represents the relationship between intermetallic particle size and intermetallic particle spacing for the tests of Example 1.

[0019] Figure 2 represents the relationship between intermetallic particle size and intermetallic particle distance for the tests of Example 2.

[0020] Figure 3 represents the relationship between intermetallic particle size and intermetallic particle distance for the tests of Example 3.

[0021] Figure 4 shows the relationship between intermetallic particle size and intermetallic particle spacing for the tests of Example 4

[0022] Figure 5 represents a BSE contrast electron microscopy image of intermetallic particles in the tests carried out

[0023] Figure 6 represents the image of Figure 5 after a first step of processing by image analysis.

[0024] Figure 7 represents the image of Figure 5 after a second processing step by image analysis comprising at least two successive steps of closing the objects allowing the calculation of the average sizes and average distances of intermetallic particles.

[0025] Figure 8 is an optical microscopy image for the tests of Example 5 with the addition of La.

[0026] Figure 9 is an optical microscopy image for the tests of Example 5 without the addition of La. DETAILED DESCRIPTION OF THE INVENTION

[0027] Unless otherwise stated, all information regarding the chemical composition of alloys is expressed as a percentage by weight based on the total weight of the alloy. The expression 1.4 Cu or 1.4 (Cu) means that the copper content expressed as a % by weight is multiplied by 1.4. The designation of alloys is made in accordance with the regulations of The Aluminium Association, known to those skilled in the art. Unless otherwise stated, the definitions of metallurgical states in standard EN515 - 2017 apply.

[0028] The present inventors have found that, surprisingly, the addition of certain elements in small quantities to AIMgSi alloys, also called 6XXX series alloys, makes it possible to modify the size and distribution of intermetallic particles and thus to tolerate an increased content of impurities, particularly iron.

[0029] Intermetallic particles are compounds containing several metallic or metalloid elements formed during solidification after the formation of crystallized aluminum in face-centered cubic form such as AhFe, Mg2Si, AlFeSi, AlFeMnSi, etc.

[0030] The alloys according to the invention are AIMgSi alloys. Thus they contain from 0.2% to 1.5% of Mg and from 0.3% to 2.0% of Si.

[0031] In one embodiment, the Mg content is at least 0.4%, or is at least 0.5%, or is at least 0.6%, or is at least 0.7%, or is at least 0.8%, or is at least 0.9%, or is at least 1.0%, or is at least 1.1%, or is at least 1.2%, or is at least 1.3%, and / or is at most 1.4%, or is at most 1.3%, or is at most 1.2%, or is at most 1.1%, or is at most 1.0%, or is at most 0.9%, or is at most 0.8%, or is at most 0.7%, or is at most 0.6%, or is at most 0.5%.

[0032] In one embodiment, the Si content is at least 0.4%, or is at least 0.5%, or is at least 0.6%, or is at least 0.7%, or is at least 0.8%, or is at least 0.9%, or is at least 1.0%, or is at least 1.1%, or is at least 1.2%, or is at least 1.3%, or is at least 1.4%, or is at least 1.5%, or is at least 1.6%, or is at least 1.7%, or is at least 1.8%, and / or is at most 1.9%, or is at most 1.8%, or is at most 1.7%, or is at most 1.6%, or is at most 1.5%, or is at most 1.4%, or is at most 1.3%, or is at most 1.2%, or is at most 1.1%, or is at most 1.0%, or is at most 0.9%, or is at most 0.8%, or is at most 0.7%, or is at most 0.6%, or is at most 0.5%.

[0033] Copper is an element that can be added to AIMgSi alloys, in particular to improve mechanical properties. The Cu content is at most 1.5% by weight. In one embodiment, the Cu content is 0.05 to 1% by weight. In one embodiment, the Cu 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%, or is at least 0.40%, or is at least 0.45%, or is at least 0.50%, or is at least 0.55%, or is at least 0.60%, or is at least 0.65%, or is at least 0.70%, or is at least 0.75%, or is at least 0.80%, or is at least 0.85%, or is at least 0.90%, or is at least 0.95%, or is at least 1.00%, or is at least 1.05%, or is at least 1.10%, or is at least 1.15%, or is at least 1.20%, or is at least 1.25%, or is at least 1.30%, or is at least 1.35%, or is at least 1.40% and / or is at most 1.45%, or is at most 1.40%, or is at most 1.35%, or is at most 1.30%, or is at most 1.25%, or is at most 1.20%, or is at most 1.15%, or is at most 1.10%, or is at most 1.05%, or 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%, 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%.

[0034] As regards the major elements Mg, Si and optionally Cu, the contents of the alloys AA6005, AA6005A, AA6105, AA6205, AA6305, AA6008, AA6009, AA6010, AA6011, AA6111, AA6012, AA6013, AA6014, AA6015, AA6016, AA6116, AA6018, AA6019, AA6020, AA6021, AA6022, AA6023, AA6024, AA6025, AA6026, AA6027, AA6028, AA6031, AA6032, AA6033, AA6040, AA6040, AA6041, AA6042, AA6043, AA6050, AA6151, AA6351, AA6053, AA6055, AA6056, AA6156, AA6060, AA6061, AA6261, AA6361, AA6162, AA6262, AA6063, AA6064, AA6065, AA6066, AA6068, AA6069, AA6070, AA6081, AA6082, AA6182, AA6086, AA6091, AA6092, AA6099 are embodiments of the invention.

[0035] The Ti content is 0.01 to 0.15% by weight. In one embodiment, the Ti content 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%. The addition of titanium, in the form of metallic titanium and / or TiBz and / or TiC is necessary to achieve the desired effect because this addition makes it possible to obtain a grain size that allows the size and distribution of the intermetallic particles to be modified. In an advantageous embodiment, metallic titanium and TiC are added.Advantageously, the addition of TiC is carried out by adding between 0.5 and 2 kg per tonne of metal and preferably between 0.8 kg and 1.2 kg per tonne of metal of AI3%TiO,15%C and / or All%TiO,2%C.

[0036] The Fe content is 0.30 to 1.0 wt.%. In one embodiment, the Fe content is at least 0.32% or is at least 0.35%, or is at least 0.40%, or is at least 0.45%, or is at least 0.50%, or is at least 0.55%, or is at least 0.60%, or is at least 0.65%, or is at least 0.70%, or is at least 0.75%, or is at least 0.80%, or is at least 0.85%, or is at least 0.90%, and / 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%, or is at most 0.45%, or is at most 0.40%, or is at most 0.35%. In one embodiment of the invention the Fe content is from 0.35 to 0.85% by weight and preferably between 0.4 and 0.7% by weight.

[0037] According to the invention, at least one element selected from Co, Ba, Ni, La, Ce, Ta, Mo, W, Nb, Re, Pr, Nd, Pm, Sm, Y, Ru, Os, the content of the element if selected being from 0.003 to 0.20% by weight, is added. The content of an element which is not selected from Co, Ba, Ni, La, Ce, Ta, Mo, W, Nb, Re, Pr, Nd, Pm, Sm, Y, Ru, Os is less than 0.003% by weight. Advantageously, at least one element selected from Co, Ba, Ni, La, Ce, Ta, the content of the element if selected being from 0.003 to 0.20% by weight, is added. In one embodiment, at least one element is selected from Co, Ba, Ni, La, Ce, Mo, W, the content of the element if selected being from 0.003 to 0.20% by weight.In one embodiment, the content of the element selected from Co, Ba, Ni, La, Ce, Ta, Mo, W, Nb, Re, Pr, Nd, Pm, Sm, Y, Ru, Os and preferably from Co, Ba, Ni, La, Ce, Ta is at least 0.004%, or is at least 0.009%, or is at least 0.014%, or is at least 0.019%, or is at least 0.024%, or is at least 0.029%, or is at least 0.034%, or is at least 0.039%, or is at least 0.044%, or is at least 0.049%, or is at least 0.054%, or is at least 0.059%, or is at least 0.064%, or is at least 0.069%, or is at least 0.074%, or is at least. 0.079%, or is at least 0.084%, or is at least 0.089%, or is at least 0.094%, or is at least 0.099%, or is at least 0.104%, or is at least 0.109%, or is at least 0.114%, or is at least 0.119%, or is at least 0.124%, or is at least 0.129%, or is at least 0.134%, or is at least 0.139%, or is at least 0.144%, or is at least 0.149%, or is at least 0.154%, or is at least 0.159%, or is at least 0.164%, or is at least 0.169%, or is at least 0.174%, or is at least 0.179%, or is at least 0.184%, or is at least 0.189%, or is at least 0.194% and / or is at most 0.195%, or is at most 0.190%, or is at most 0.185%, or is at most 0.180%, or is at most 0.175%, or is at most 0.170%, or is at most 0.165%, or is at most 0.160%, or is at most 0.155%, or is at most 0.150%, or is at most 0.145%, or 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%, or is at most 0.040%, or is at most 0.035%, or is at most 0.030%, or is at most 0.025%, or is at most 0.020%, or is at most 0.015%, or is at most 0.010%.

[0038] In one embodiment, at least one element selected from Co, Ba, Ni, La, Ce, Ta, Mo, W, Nb, Re, Pr, Nd, Pm, Sm, Y, Ru, Os, the content of the element if selected being from 0.009 to 0.090% by weight, is added.

[0039] In an advantageous embodiment at least one element is chosen from Co, Ba, Ni, La, Ce, Ta, the content of the element if chosen being from 0.005 to 0.15% by weight.

[0040] The Zr content is at most 0.15% by weight. In an advantageous embodiment, the Zr content is 0.003 to 0.15% by weight. In one embodiment, the Zr content is at least 0.004%, or is at least 0.009%, or is at least 0.014%, or is at least 0.019%, or is at least 0.024%, or is at least 0.029%, or is at least 0.034%, or is at least 0.039%, or is at least 0.044%, or is at least 0.049%, or is at least 0.054%, or is at least 0.059%, or is at least 0.064%, or is at least 0.069%, or is at least 0.074%, or is at least 0.079%, or is at least 0.084%, or is at least 0.089%, or is at least 0.094%, or is at least 0.099%, or is at least 0.104%, or is at least 0.109%, or is at least 0.114%, or is at least 0.119%, or is at least 0.124%, or is at least 0.129%, or is at least 0.134%, or is at least 0.139% and / or is at most 0.145%, or 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%, or is at most 0.040%, or is at most 0.035%, or is at most 0.030%, or is at most 0.025%, or is at most 0.020%, or is at plus 0.015%, or is at most 0.010%.,

[0041] The Mn content is at most 1.5% by weight. In an advantageous embodiment of the invention, the Mn content is 0.03 to 1.0% by weight. In one embodiment, the Mn content is at least 0.05%, or 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%, or is at least 0.40%, or is at least 0.45%, or is at least 0.50%, or is at least 0.55%, or is at least 0.60%, or is at least 0.65%, or is at least 0.70%, or is at least 0.75%, or is at least 0.80%, or is at least 0.85%, or is at least 0.90%, or is at least 0.95%, or is at least 1.00%, or is at least 1.05%, or is at least 1.10%, or is at least 1.15%, or is at least 1.20%, or is at least 1.25%, or is at least 1.30%, or is at least 1.35%, or is at least less than 1.40% and / or is at most 1.45%, or is at most 1.40%, or is at most 1.35%, or is at most 1.30%, or is at most 1.25%, or is at most 1.20%, or is at most 1.15%, or is at most 1.10%, or is at most 1.05%, or 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%, or is at most 0.45%, or is at most plus 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%.

[0042] The V content is at most 0.20% by weight. In one embodiment of the invention the V content is 0.05 to 0.20% by weight. In one embodiment, the V content 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%.

[0043] The Zn content is at most 1.0% by weight. In one embodiment, the Zn content is 0.03 to 1.0% by weight. In one embodiment, the Zn content is at least 0.05%, or 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%, or is at least 0.40%, or is at least 0.45%, or is at least 0.50%, or is at least 0.55%, or is at least 0.60%, or is at least 0.65%, or is at least 0.70%, or is at least 0.75%, or is at least 0.80%, or is at least 0.85%, or is at least 0.90%, and / 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%, 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%.

[0044] The Cr content is at most 0.25% by weight. In one embodiment the Cr content is from 0.01 to 0.25% by weight. In one embodiment the Cr content 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%, or is at least 0.19%, or is at least 0.20%, or is at least 0.21%, or is at least 0.22%, or is at least 0.23%, and / or is at most 0.24%, or is at most 0.23%, or is at most 0.22%, or is at most 0.21%, or is at most 0.20%, 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 plus 0.04%, or is at most 0.03%.

[0045] The other elements are unavoidable impurities whose content is typically at most 0.05% by weight, or at most 0.04%, or at most 0.03%, or at most 0.02%, or at most 0.01%. It is understood as usual that the maximum content relates to each of the unavoidable impurities. Advantageously, the total of the unavoidable impurities is at most 0.15% by weight, or at most 0.12%, at most 0.10%, at most 0.08%, at most 0.06%. In one embodiment, among the unavoidable impurities, the Sc content is at most 0.020% by weight, or at most 0.015%, or at most 0.0010%, or at most 0.005%, or at most 0.002%.

[0046] The rest is aluminum.

[0047] In one embodiment of the invention, the alloy comprises at least two elements chosen from Co, Ni, Ba, La, Ce, Ta, Ru, Os and Zr, the content of the element if chosen being from 0.003 to 0.15% by weight, the sum of the content of the elements chosen being at least equal to 0.08% by weight and at least one of the elements chosen having a content of 0.04% to 0.15% by weight and preferably from 0.05 to 0.10%.

[0048] In one embodiment of the invention, the alloy comprises at least three elements selected from Co, Ni, Ba, La, Ce, Ta, Ru, Os and Zr, the content of the element if selected being from 0.003 to 0.15% by weight, the sum of the content of the selected elements being at least equal to 0.14% by weight and at least one of the selected elements having a content of 0.04% to 0.15% by weight. Preferably in this embodiment, the selected elements are Co, Ba, Zr or Ni, Ba, Zr, or Co, La, Zr or Co, Ni, Ba.

[0049] The alloys according to the invention have the advantage of having a reduced average size of the intermetallic particles and an average distance between the intermetallic particles compared to the alloys according to the prior art. The intermetallic particles are less harmful, in particular for shaping, when they are small in size and not very far from each other. The alloys according to the invention are therefore advantageous for reducing process times such as homogenization, for improving the properties linked to shaping such as elongation and formability and improve surface properties such as response to anodizing.

[0050] An object of the invention is a heat-treated wrought product comprising an alloy according to the invention. By heat-treated product is meant in the context of the invention a product in a T state, which means a heat-treated alloy product heat-treated to obtain stable states other than F, O or H. Typically, the heat-treated product is in a T3, T4, T5, T6, T7 or T8 state.

[0051] An object of the invention is a rolled product comprising an alloy according to the invention. A rolled product according to the invention typically has a thickness of 0.5 mm to 300 mm and preferably of 0.8 mm to 150 mm. In an advantageous embodiment the rolled product according to the invention has a thickness of 0.8 mm to 1.5 mm and its bending angle has m , determined according to standard NF EN ISO 7438 and procedures VDA 238-100 and VDA 239-200, is at least 112° and preferably at least 114°.

[0052] Another subject of the invention is a spun product comprising an alloy according to the invention. A spun product according to the invention typically has a thickness of 0.5 mm to 30 mm and preferably of 0.8 mm to 20 mm. Another subject of the invention is a forged product comprising an alloy according to the invention. A forged product according to the invention typically has a thickness of 0.5 mm to 300 mm and preferably of 0.8 mm to 150 mm.

[0053] A method for obtaining a heat-treated wrought product according to the invention comprises the steps of - Supply of pure or alloyed aluminium in the form of primary metal ingots from electrolysis and / or pre-consumer manufacturing scrap and / or post-consumer waste, said waste having optionally been melted separately and possibly solidified and addition elements in appropriate form; - Creation of a charge with the supplied aluminium, melting of this charge and addition of the additive elements to obtain a bath of liquid metal in alloy according to the invention, - Casting, preferably by vertical semi-continuous casting with direct cooling, of said liquid metal bath to obtain a blank suitable for hot working, typically a rolling plate, a forging blank or a billet; - Homogenization of the roughing at a temperature of at least 500°C; - Hot and optionally cold working of the blank by rolling, extrusion and / or forging to obtain a wrought product; - Dissolving the wrought product thus obtained at a temperature of at least 500°C and quenching; - Aging at room temperature and / or tempering of the wrought product put into solution and quenched thus obtained to obtain a heat-treated wrought product.

[0054] In a first step, pure or alloyed aluminium is supplied in the form of primary metal ingots from electrolysis and / or pre-consumer manufacturing scrap and / or post-consumer waste, which has optionally been melted separately and possibly solidified, and additional elements in appropriate form.

[0055] Pure or alloyed aluminum in the form of primary metal ingot generally has the disadvantage of generating significant CO2 emissions during its manufacture and we therefore try to limit its use. In the context of the invention, the term ingot means all possible forms of solidified metal. With regard to other sources of metal, we distinguish pre-consumer manufacturing scrap, which is generated before the metal is delivered to the end customer: the window buyer, the vacuum chamber user, the car buyer, the airline, etc., and post-consumer waste which is recovered after use of the product, typically from the car at the scrapyard. The manufacturing stages of aluminum products generate numerous pre-consumer manufacturing scraps during all stages.Examples of post-consumer waste include 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 sheet metal or profile manufacturing process, the skeletons of blanks used for stamping, machining chips, etc. Examples of post-consumer waste include used window frames, scrapped car parts, crushed cars, dismantled aircraft, etc. Post-consumer waste can be supplied raw, in compacted form, or optionally after being melted separately and possibly solidified. Additional elements are also supplied in suitable forms. These can be elements in their metallic form or in an alloyed form. For the addition of rare earths such as La, Ce, and Nd, it is advantageous to use mischmetal as the addition form.

[0056] In a subsequent step, a charge is formed with all or part of the supplied aluminum, this charge is melted and additional elements are added to obtain a bath of liquid metal having a composition according to the invention. It is possible that part of the supplied aluminum is already in liquid form.

[0057] The method according to the invention is advantageous because it allows, when constituting the load, to use a high percentage of manufacturing scraps and / or post-consumer waste. Thus, in one embodiment, the load contains at least 20% or at least 30% or at least 40% or at least 50% or at least 60% or at least 70% or at least 80% of manufacturing scraps. Thus, in one embodiment, the load contains at least 20% or at least 30% or at least 40% or at least 50% or at least 60% or at least 70% or at least 80% of post-consumer waste. Thus, in one embodiment, the load contains at least 20% or at least 30% or at least 40% or at least 50% or at least 60% or at least 70% or at least 80% of manufacturing scraps and post-consumer waste. The charge is then melted and its composition adjusted using the addition elements to obtain a bath of liquid metal having a composition according to the invention.

[0058] In a subsequent step, the liquid metal bath is cast, preferably by direct-cooled vertical semi-continuous casting, to obtain a blank suitable for hot working, typically a rolling plate or billet.

[0059] In a subsequent step, the blank thus obtained is homogenized to a temperature of at least 500°C. The homogenization time during which the entire blank has reached a temperature of at least 500°C is typically at least 2 hours or at least 3 hours or at least 4 hours or at least 5 hours or at least 6 hours. The alloys according to the invention make it possible, in certain embodiments, to reduce the homogenization time. Thus, the homogenization time during which the entire blank has reached a temperature of at least 500°C is advantageously at most 12 hours or at most 11 hours or at most 10 hours or at most 9 hours or at most 8 hours.

[0060] In a subsequent step, the blank thus homogenized is hot worked and optionally cold worked by rolling, extrusion and / or forging to obtain a wrought product. Hot working is typically started at a temperature of at least 400°C. In one embodiment, the blank is cooled from the homogenization temperature to the temperature at which working begins, optionally by forced cooling. In another embodiment, the blank is cooled to room temperature after homogenization and then reheated to reach the temperature at which hot working begins.

[0061] In a subsequent step, the wrought product thus obtained is dissolved at a temperature of at least 500°C and quenched. Quenching is typically carried out in water by immersion or spraying, however air quenching is also possible for certain products, particularly extruded products.

[0062] In an optional subsequent step, the wrought product thus put into solution and quenched can be cold worked and / or stress relieved.

[0063] In a subsequent step, aging at room temperature and / or tempering of the solution-treated and quenched wrought product thus obtained is carried out to obtain a heat-treated wrought product.

[0064] Among the uses of the products according to the invention, we can cite in particular automobile construction (for example, body skin and reinforcement, shock absorption system, battery boxes), building construction (for example, framework, joinery, decoration, etc.), aeronautical construction (for example, fuselage, electrical connections, etc.) and industrial construction (for example, pylons, vacuum chambers, railway tracks). EXAMPLES

[0065] Example 1

[0066] In this example, aluminum alloy parts were cast and homogenized for 8 hours at 540 °C. An AI31Ï0.15C refining agent was added in the proportion of 1 kg / t. The composition of the parts is given in Table 1 below.

[0067] [Table 1] - Composition of alloys in % by weight

[0068] The intermetallic particles of the parts were characterized by scanning electron microscopy on areas of 3300 x 3300 pm2. Two parameters were characterized by image analysis: the average size of the intermetallic particles and the average distance between the intermetallic particles. The characterization method is illustrated in Figures 5, 6 and 7. Images of the intermetallic particles obtained BSD (Backscatter Diffraction), such as in Figure 5, are corrected and binarized (Figure 6) and the images undergo at least two successive stages of object closure to be able to quantify the particle sizes. intermetallic particles and the distances between intermetallic particles (Figure 7). Image analysis closure steps are performed to measure the average size of the intermetallic particles and the average distance between the intermetallic particles.

[0069] The results are presented in Table 2 and plotted in Figure 1, in % relative to the reference sample C1H. It is indeed more relevant to present the results in percentage, as the absolute values ​​can be affected by experimental parameters.

[0070] [Table 2] -

[0071] Intermetallic particles are less harmful, especially for shaping, when they are small and not very far from each other. These two parameters are correlated in fact, the iron content being constant in the test, the total volume of intermetallic particles is substantially constant in the different tests.

[0072] Example 2

[0073] In this example, aluminum alloy parts were cast and homogenized 8 hours at 540 °C. A refining agent AI3TÎ0.15C was added in the proportion of lkg / t. The composition of the pieces is given in Table 3 below.

[0074] [Table 3] - Composition of alloys in % by weight

[0075] The intermetallic particles of the parts were characterized by scanning electron microscopy on areas of 3300 x 3300 pm2. Two parameters were characterized by image analysis: the average size of the intermetallic particles and the average distance between the intermetallic particles.

[0076] The results are presented in Table 4 and plotted in Figure 2, as a % relative to the reference sample C16H. It is indeed more relevant to present the results as a percentage, as the absolute values ​​may be affected by experimental parameters.

[0077] [Table 4] -

[0078] Intermetallic particles are less harmful, especially for shaping, when they are small and not very far from each other. These two parameters are correlated in fact, the iron content being constant in the test, the total volume of intermetallic particles is substantially constant in the different tests.

[0079] Example 3

[0080] In this example, aluminum alloy parts were cast and homogenized for 8 hours at 540 °C. A refining agent AI3TÎ0.15C was added in the proportion of lkg / t. The composition of the parts is given in Table 5 below.

[0081] [Table 5] - Composition of alloys in % by weight

[0082] The intermetallic particles of the parts were characterized by scanning electron microscopy on areas of 3300 x 3300 pm2. Two parameters were characterized by image analysis: the average size of the intermetallic particles and the average distance between the intermetallic particles.

[0083] The results are presented in Table 6 and represented in Figure 3, in % compared to the reference sample D4. It is indeed more relevant to present the results in percentage, the absolute values ​​can be affected by experimental parameters.

[0084] [Table 6] -

[0085] Example 4

[0086] In this example, aluminum alloy parts were cast and homogenized 8 hours at 540 °C. A refining agent AI3TÎ0.15C was added in the proportion of lkg / t. The composition of the pieces is given in Table 7 below.

[0087] [Table 7] - Composition of alloys in % by weight

[0088] The intermetallic particles of the parts were characterized by scanning electron microscopy on areas of 3300 x 3300 pm2. Two parameters were characterized by image analysis: the average size of the intermetallic particles and the average distance between the intermetallic particles.

[0089] The results are presented in Table 8 and represented in Figure 4, in % compared to the reference sample D5. It is indeed more relevant to present the results in percentage, the absolute values ​​can be affected by experimental parameters.

[0090] [Table 8] -

[0091] Intermetallic particles are less harmful, especially for shaping, when they are small and not very far from each other. These two parameters are correlated in fact, the iron content being constant in the test, the total volume of intermetallic particles is substantially constant in the different tests.

[0092] Example 5

[0093] In this example, parts made of 6082 aluminum alloy, to which 1% by weight of iron and, for one of the tests, 0.2% by weight of La had been added, were cast.

[0094] The intermetallic particles of the parts were characterized by optical microscopy. The results are presented in Figure 8, with La addition and Figure 9, without La addition. The intermetallic particles are smaller in the case of La addition and their distribution is refined by 35% compared to the reference without La.

[0095] Example 6

[0096] In this example, industrial-sized plates of aluminum alloy were cast. An AI3TÎ0.15C refining agent was added in the proportion of lkg / t. The composition of the plates is given in Table 9 below. All three alloys comply with the registration of alloy AA6016A, however the iron content of alloy E1 is typical of a standard industrial grade while the iron content of alloys E2 and E3 is typical of alloys with a high recycled content.

[0097] [Table 9] - Composition of alloys in % by weight

[0098] The plates were homogenized at 560°C for 3 hours then at 535°C for 1 hour then hot and cold rolled to obtain sheets with a thickness of 1.2 mm.

[0099] Sheets of 1.2 mm thickness were solution-treated for 1 hour at 520°C, quenched, pre-tempered for 8 hours at 85°C and matured for 21 days at room temperature. The mechanical performances in the bending test according to standard NF EN ISO 7438 and procedures VDA 238-100 and VDA 239-200 of these sheets were characterized in the transverse direction relative to the rolling direction, after a pre-tension of 14% in this direction.

[0100] The results obtained are given in Table 10

[0101] Table 10. Bending test result

[0102] By adding Co and Zr, the bending performance of an AA6016A alloy with a high iron content can be brought down to that of an AA6016A alloy with a standard iron content.

Claims

CLAIMS Aluminum-based alloy comprising, in % by weight, - Mg: 0.2 - 1.5; - If: 0.3 - 2.0; - Fe: 0.30 - 1.0; - Ti: 0.01 - 0.15; - at least one element chosen from Co, Ba, Ni, La, Ce, Ta, Mo, W, Nb, Re, Pr, Nd, Pm, Sm, Y, Ru, Os the content of the element if chosen being from 0.003 to 0.20 and preferably from 0.005 to 0.15, - Zr: <0.15; - Mn: <1.5; - V: <0.20; - Zn: <1.0; - Cr: <0.25; - Cu: < 1.5; - remainder aluminum and unavoidable impurities, the content of which is at most 0.05% by weight. Alloy according to claim 1 comprising, in % by weight, Zr: 0.003 - 0.15 and / or Mn: 0.03 - 1.0 and / or V: 0.05 - 0.20 and / or Zn: 0.03 - 1.0 and / or Cr: 0.01 - 0.25 and / or Cu: 0.05 - 1.

0. An alloy according to claim 1 or claim 2 wherein the alloy comprises at least two elements selected from Co, Ni, Ba, La, Ce, Ta, Ru, Os and Zr the content of the element if selected being from 0.003 to 0.15% by weight, the sum of the content of the selected elements being at least equal to 0.08% by weight and at least one of the selected elements having a content of from 0.04% to 0.15% by weight.Alloy according to any one of claims 1 to 3 wherein the alloy comprises at least three elements chosen from Co, Ni, Ba, La Ce, Ta, Ru, Os and Zr the content of the element if chosen being from 0.003 to 0.15% by weight, the sum of the content of the chosen elements being at least equal to 0.14% by weight and at least one of the chosen elements having a content of 0.04% to 0.15% by weight. Alloy according to claim 4 wherein the chosen elements are Co, Ba, Zr or Ni, Ba, Zr or Co, La, Zr or Co, Ni, Ba. Alloy according to any one of claims 1 to 5 wherein the Fe content is from 0.35 to 0.85% by weight and preferably between 0.4 and 0.7% by weight. Heat-treated wrought product comprising an alloy according to any one of claims 1 to 6. Wrought product according to claim 7 wherein the wrought product is a rolled product having a thickness of 0.5 mm to 300 mm and preferably of 0.8 mm to 150 mm. Wrought product according to claim 8 characterized in that its thickness is of 0.8 mm to 1.5 mm and its bending angle a m, determined according to standard NF EN ISO 7438 and procedures VDA 238-100 and VDA 239-200, is at least 112° and preferably at least 114°. Wrought product according to claim 7 wherein the wrought product is an extruded product having a thickness of 0.5 mm to 30 mm and preferably of 0.8 mm to 20 mm. Wrought product according to claim 7 wherein the wrought product is a forged product having locally a thickness of 0.5 mm to 300 mm and preferably of 0.8 mm to 150 mm. A method of manufacturing a product according to any one of claims 7 to 11 comprising the steps of - Supply of pure or alloyed aluminium in the form of primary metal ingots from electrolysis and / or pre-consumer manufacturing scrap and / or post-consumer waste, said waste having optionally been melted separately and possibly solidified and addition elements in appropriate form; - Creation of a charge with the supplied aluminium, melting of this charge and addition of the additive elements to obtain a bath of liquid metal in alloy according to the invention, - Casting, preferably by vertical semi-continuous casting with direct cooling, of said liquid metal bath to obtain a blank suitable for hot working, typically a rolling plate, a forging blank or a billet; - Homogenization of the roughing at a temperature of at least 500°C; - Hot and optionally cold working of the blank by rolling, extrusion and / or forging to obtain a wrought product; - Dissolving the wrought product thus obtained at a temperature of at least 500°C and quenching; - Aging at room temperature and / or tempering of the wrought product put into solution and quenched thus obtained to obtain a heat-treated wrought product. A method according to claim 12 wherein the feedstock contains at least 30% post-consumer waste. A method according to claim 12 or claim 13 wherein the titanium is added in the form of metallic titanium and TiC. Use of a product according to any one of claims 7 to 11 for automotive construction, building construction, aircraft construction or industrial construction

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