6XXX aluminum alloys with improved recyclability.

Abstract

The present invention relates to an AlMgSi alloy, particularly suitable for recycling. The subject of the present invention is an aluminum-based alloy containing, by weight percent, 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, with the selected element content being 0.003-0.20, preferably 0.005-0.15, Zr: ≦0.15, Mn: ≦1.5, V: ≦0.20, Zn: ≦1.0, Cr: ≦0.25, Cu: ≦1.5, and the remainder being aluminum and unavoidable impurities. The addition of small amounts of certain elements allows for the modification of the size and distribution of intermetallic compound particles, thus allowing for the tolerance of increased impurity content, especially iron. The present invention also relates to a heat-treated wrought product comprising the alloy of the present invention and a method for making the same, which is particularly useful in automotive, building, aircraft or industrial construction.

Description

[Technical Field]

[0001] The present invention relates to a 6XXX series aluminum alloy, and in particular to a 6XXX series aluminum alloy that can improve the recycling rate of this type of alloy in wrought materials in the automotive field. [Background technology]

[0002] Aluminum recycling offers economical and environmentally friendly advantages. The production of secondary aluminum requires up to 95% less energy than primary aluminum, potentially reducing CO2 emissions. To address concerns about the environmental impact of aluminum production, the aluminum industry strives to maximize the proportion of recycled material in its products. However, increasing the proportion of recycled material generally leads to increased impurity content, especially iron content, resulting in a large volume fraction and / or size of intermetallic particles that can be detrimental to processing durations such as homogenization, forming-related properties such as elongation and formability, and surface properties such as anodization response. This difficulty is discussed, for example, in the paper "Structure Control by Thermomechanical Processing of AA6xxx Al-Mg-Si Sheet Alloys for Automotive Applications—A Review," published in Materials Science and Engineering journal A336 (2002) 249-262.

[0003] To avoid this detrimental effect, one may consider purifying the metal.

[0004] French Patent No. 2902800 describes a method for producing remelted blocks from scrap of alloys of the 2XXX or 7XXX series, which can be refined to produce, among other things, iron and silicon, without removing additional elements such as zinc, copper, magnesium, etc.

[0005] However, these additional refining steps can prove difficult and costly to implement.

[0006] WO 2015 / 151907 also addresses the issue of impurity content in recycled alloys.

[0007] US Patent Application Publication No. 2008 / 0175747 describes alloys in which impurities have little effect on the properties.

[0008] Japanese Patent Application Laid-Open No. 2007-169740 describes an alloy containing, in mass %, Si: 0.5 to 1.5%, Mg: 0.2 to 2.0%, Fe: 1.5% or less, Mn: 1.0% or less, Cr: 0.5% or less, Zr: 0.5% or less, V: 0.3% or less, Ti: 0.2% or less, Zn=1.5% or less, Cu: 1.0% or less, and further, the total content of Bi, Sn, Ga, Co, Ni, Ca, Mo, Be, Pb, and W is 0.015% or more and 0.5% or less, with the remainder being aluminum and impurities.

[0009] Japanese Patent Application Laid-Open No. 2016-037632 describes an aluminum alloy sheet containing 0.2 to 2.0 mass% Mg, 0.3 to 2.0 mass% Si, and 0.01 to 0.5 mass% Fe, as well as 0.002 to 0.3 mass% in total of one or both of Ni and Co, with the remainder being Al and unavoidable impurities.

[0010] EP 2072628 describes extruded or forged products made of an aluminum alloy of the AlMgSi type, containing, in weight percent, 0.5 to 0.95 Si, 0.6 to 0.95 Mg, 0.1 to 0.3 Mn, 0.05 to 0.25 V, 0.05 to 0.25 Ni, at most 0.3 Cu, possibly one or two elements selected from the group consisting of (0.05 to 0.2 Cr and 0.05 to 0.2 Zr), less than 0.2 Zn, less than 0.5 Fe, less than 0.1 Ti, unavoidable impurities, and the remainder being aluminum.

[0011] China Patent Application Publication No. 112342443 relates to an explosion-proof barrier material containing, by weight, 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 being aluminum.

[0012] US Patent Application Publication No. 2020 / 095664 relates to high strength aluminum alloys and methods for making and processing these alloys.

[0013] Chinese Patent Publication No. 106756320 relates to a rolling rack made of an aluminum alloy containing, by weight, 1.5% to 2.0% Mg, 1% to 1.4% Si, 0.2% to 0.5% Fe, 0.05% to 0.09% Zn, 0.1% to 0.3% Cu, 0.2% to 0.4% Mn, 0.01% to 0.04% C, 0.2% to 0.4% B, 0.02% to 0.04% W, 0.05% to 0.07% Zr, 0.1% to 0.4% Cr, 0.05% to 0.09% Ti, 20% to 35% aluminum part scrap, 0.5% to 1.5% rare earth elements, and the remainder being aluminum. [Prior art documents] [Patent documents]

[0014] [Patent Document 1] French Patent Invention No. 2902800 [Patent Document 2] International Publication No. 2015 / 151907 [Patent Document 3] US Patent Application Publication No. 2008 / 0175747 [Patent Document 4] Japanese Patent Application Laid-Open No. 2007-169740 [Patent Document 5] Japanese Patent Application Publication No. 2016-037632 [Patent Document 6] European Patent No. 2072628 Summary of the Invention [Problem to be solved by the invention]

[0015] The problem that the present invention aims to solve is therefore to propose an alloy that can tolerate an increased content of impurities, in particular iron, without requiring additional refining and without limiting the duration of homogenization. [Means for solving the problem]

[0016] The first object of the present invention is to provide, in weight percent, - Mg: 0.2~1.5, - Si: 0.3~2.0, - Fe: 0.30~1.0, - 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, Os, the content of which, when selected, is between 0.003 and 0.20, preferably between 0.005 and 0.15; - Zr:≦0.15, - Mn:≦1.5, - V:≦0.20, - Zn: ≤ 1.0, - Cr:≦0.25, - Cu:≦1.5, Including, the remainder being aluminum and unavoidable impurities with a content of at most 0.05% by weight, It is an aluminum-based alloy.

[0017] Another subject of the invention is a heat-treated wrought product comprising an alloy according to the invention.

[0018] Another object of the present invention is a method for producing a heat-treated wrought material according to the invention, comprising the following steps: - providing pure or alloyed aluminium in the form of primary metal ingots derived from electrolysis and / or pre-consumer production scrap and / or post-consumer scrap, and additional elements in suitable forms, said scrap optionally being melted and possibly solidified separately, - forming a charge using the supplied aluminum, melting this charge and adding the additive elements to obtain a liquid alloy metal bath according to the invention; - casting said liquid metal bath, preferably by direct-cooled vertical semi-continuous casting, to obtain blanks suitable for hot working, typically rolled plates, forged blanks or billets, - homogenizing the blank at a temperature of at least 500°C; - hot working, by rolling, extrusion and / or forging, and optionally cold working, of the blank to obtain a wrought product, - solution treatment of the wrought material thus obtained at a temperature of at least 500°C and quenching; - ageing and / or tempering the solution-treated and quenched wrought material thus obtained at room temperature to obtain a heat-treated wrought material; The manufacturing method includes: A further subject of the invention is the use of the product according to the invention for automotive, building, aircraft or industrial construction. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is a graph showing the relationship between the size of intermetallic compound particles and the distance between intermetallic compound particles in the test of Example 1. [Figure 2] FIG. 10 is a graph showing the relationship between the size of intermetallic compound particles and the distance between intermetallic compound particles in the test of Example 2. [Figure 3] FIG. 10 is a graph showing the relationship between the size of intermetallic compound particles and the distance between intermetallic compound particles in the test of Example 3. [Figure 4]FIG. 10 is a graph showing the relationship between the size of intermetallic compound particles and the distance between intermetallic compound particles in the test of Example 4. [Figure 5] FIG. 1 shows BSE contrast electron microscope images of intermetallic particles in the tests performed. [Figure 6] FIG. 6 shows the image of FIG. 5 after a first step of processing by image analysis. [Figure 7] FIG. 6 shows the image of FIG. 5 after a second step of processing by image analysis, which includes at least two successive steps of closing the object, allowing the calculation of the average size and average distance of the intermetallic grains. [Figure 8] 10 is an optical microscope image of the test of Example 5 with La addition. [Figure 9] 10 is an optical microscope image of the test of Example 5 without La addition. DETAILED DESCRIPTION OF THE INVENTION

[0020] Unless otherwise specified, all indications of alloy chemical composition are expressed in weight percent based on the total weight of the alloy. The expression 1.4Cu or 1.4(Cu) means that the copper content, expressed in weight percent, is multiplied by 1.4. Alloys are designated according to Aluminum Association rules, which are well known to those skilled in the art. Unless otherwise specified, the metallurgical temper definitions of standard EN515-2017 apply.

[0021] The present inventors have surprisingly discovered that by adding small amounts of certain elements to AlMgSi alloys, also referred to as 6XXX series alloys, the size and distribution of intermetallic grains can be modified, thereby allowing for tolerance of increased impurity content, particularly iron.

[0022] Intermetallic compound particles refer to compounds containing multiple metallic or semi-metallic elements that are formed during solidification after the formation of face-centered cubic crystallized aluminum, such as Al3Fe, Mg2Si, AlFeSi, and AlFeMnSi.

[0023] The alloy according to the present invention is an AlMgSi alloy, and therefore contains 0.2% to 1.5% Mg and 0.3% to 2.0% Si.

[0024] In one embodiment, the Mg content is at least 0.4%, or at least 0.5%, or at least 0.6%, or at least 0.7%, or at least 0.8%, or at least 0.9%, or at least 1.0%, or at least 1.1%, or at least 1.2%, or at least 1.3%, and / or at most 1.4%, or at most 1.3%, or at most 1.2%, or at most 1.1%, or at most 1.0%, or at most 0.9%, or at most 0.8%, or at most 0.7%, or at most 0.6%, or at most 0.5%.

[0025] In one embodiment, the Si content is at least 0.4%, or at least 0.5%, or at least 0.6%, or at least 0.7%, or at least 0.8%, or at least 0.9%, or at least 1.0%, or at least 1.1%, or at least 1.2%, or at least 1.3%, or at least 1.4%, or at least 1.5%, or at least 1.6%, or at least 1.7%, or at least 1.8%, and / or at most 1.9%, or at most 1.8%, or at most 1.7%, or at most 1.6%, or at most 1.5%, or at most 1.4%, or at most 1.3%, or at most 1.2%, or at most 1.1%, or at most 1.0%, or at most 0.9%, or at most 0.8%, or at most 0.7%, or at most 0.6%, or at most 0.5%.

[0026] Copper is an element that can be added to AlMgSi alloys, especially to improve their mechanical properties. The Cu content is at most 1.5 wt. %. In one embodiment, the Cu content is between 0.05 and 1 wt. %. In one embodiment, the Cu content is at least 0.10%, or at least 0.15%, or at least 0.20%, or at least 0.25%, or at least 0.30%, or at least 0.35%, or at least 0.40%, or at least 0.45%, or at least 0.50%, or at least 0.55%, or at least 0.60%, or at least 0.65%, or at least 0.70%, or at least 0.75%, or at least 0.80%, or at least 0.85%, or at least 0.90%, or at least 0.95%, or at least 1.00%, or at least 1.05%, or at least 1.10%, or at least 1.15%, or at least 1.20%, or at least 1.25%, or at least 1.30%, or at least 1.3 5%, or at least 1.40%, and / or at most 1.45%, or at most 1.40%, or at most 1.35%, or at most 1.30%, or at most 1.25%, or at most 1.20%, or at most 1.15%, or at most 1.10%, or at most 1.05%, or at most 1.00%, or at most 0.95%, or at most 0.90%, or at most 0.8 5%, or at most 0.80%, or at most 0.75%, or at most 0.70%, or at most 0.65%, or at most 0.60%, or at most 0.55%, or at most 0.50%, or at most 0.45%, or at most 0.40%, or at most 0.35%, or at most 0.30%, or at most 0.25%, or at most 0.20%, or at most 0.15%.

[0027] With respect to the major elements Mg, Si and optionally Cu, 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, AA The content of 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 is an embodiment of the present invention.

[0028] The Ti content is 0.01 to 0.15% by weight. In one embodiment, the Ti content is at least 0.02%, or at least 0.03%, or at least 0.04%, or at least 0.05%, or at least 0.06%, or at least 0.07%, or at least 0.08%, or at least 0.09%, or at least 0.10%, or at least 0.11%, or at least 0.12%, or at least 0.13%, and / or at most 0.14%, or at most 0.13%, or at most 0.12%, or at most 0.11%, or at most 0.10%, or at most 0.09%, or at most 0.08%, or at most 0.07%, or at most 0.06%, or at most 0.05%, or at most 0.04%, or at most 0.03%. The addition of titanium in the form of metallic titanium and / or TiB2 and / or TiC is necessary to achieve the desired effect, as this addition allows for obtaining a particle size that allows for modifying the size and distribution of intermetallic particles. In an advantageous embodiment, metallic titanium and TiC are added. Advantageously, the addition of TiC is carried out by adding 0.5 to 2 kg per ton of metal, preferably 0.8 to 1.2 kg per ton of metal, of Al3%Ti0.15%C and / or Al1%Ti0.2%C.

[0029] The Fe content is 0.30 to 1.0 wt %. In one embodiment, the Fe content is at least 0.32%, or at least 0.35%, or at least 0.40%, or at least 0.45%, or at least 0.50%, or at least 0.55%, or at least 0.60%, or at least 0.65%, or at least 0.70%, or at least 0.75%, or at least 0.80%, or at least 0.85%, or at least 0.90%, and / or at most 0.95%, or at most 0.90%, or at most 0.85%, or at most 0.80%, or at most 0.75%, or at most 0.70%, or at most 0.65%, or at most 0.60%, or at most 0.55%, or at most 0.50%, or at most 0.45%, or at most 0.40%, or at most 0.35%. In one embodiment of the present invention, the Fe content is 0.35 to 0.85% by weight, preferably 0.4 to 0.7% by weight.

[0030] 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 is added in a content of 0.003 to 0.20 wt.% when selected. The content of elements 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 wt.%. Advantageously, at least one element selected from Co, Ba, Ni, La, Ce, Ta is added in a content of 0.003 to 0.20 wt.% when selected. In one embodiment, the at least one element is selected from Co, Ba, Ni, La, Ce, Mo, W in a content of 0.003 to 0.20 wt.% when selected. In one embodiment, the content of elements selected from Co, Ba, Ni, La, Ce, Ta, Mo, W, Nb, Re, Pr, Nd, Pm, Sm, Y, Ru, Os, preferably from Co, Ba, Ni, La, Ce, Ta, is at least 0.004%, or at least 0.009%, or at least 0.014%, or at least 0.019%, or at least 0.024%, or at least 0.029%, or at least 0.034%, or at least 0.039%, or at least 0.044%, or at least 0.049%, or at least 0.054%, or at least 0.059%, or at least 0.064%, or at least 0.069%, or at least 0.074%, or at least 0.079%, or at least 0.084%, or at least 0.089%, or at least 0.094%, or at least 0.099%, or at least 0.104%, or at least 0.109%, or at least 0.114%, or at least 0.119%, or at least 0.124%, or at least 0.129%, or at least 0.134%, or at least 0.139%, or at least 0.144%, or at least 0.149%, or at least 0.154%, or at least 0.159%, or at least 0.164%, or at least 0.169%, or at least 0.174%, or at least 0.179%, or at least 0.184%, or at least 0.189%, or at least 0.194%, and / or at most 0.195%, or at most 0.190%, or at most 0.185%, or at most 0.180%, or at most 0.175%, or at most 0.170%, or at most 0.165%, or at most 0.160%, or at most 0.155%, or at most 0.150%, or at most 0.145%, or at most 0.140%, or at most 0.135%, or at most 0.130%, or at most 0.125%, or at most 0.120%, or at most 0.115%, and is at most 0.110%, or at most 0.105%, or at most 0.100%, or at most 0.095%, or at most 0.090%, or at most 0.085%, or at most 0.080%, or at most 0.075%, or at most 0.070%, or at most 0.065%, or at most 0.060%, or at most 0.055%, or at most 0.050%, or at most 0.045%, or at most 0.040%, or at most 0.035%, or at most 0.030%, or at most 0.025%, or at most 0.020%, or at most 0.015%, or at most 0.010%.

[0031] 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 is added, the content of the element being 0.009 to 0.090 wt.% when selected.

[0032] In an advantageous embodiment, the at least one element is selected from among Co, Ba, Ni, La, Ce, Ta, with the content of the element in the selected case being between 0.005 and 0.15% by weight.

[0033] 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 at least 0.009%, or at least 0.014%, or at least 0.019%, or at least 0.024%, or at least 0.029%, or at least 0.034%, or at least 0.039%, or at least 0.044%, or at least 0.049%, or at least 0.054%, or at least 0.059%, or at least 0.064%. , or at least 0.069%, or at least 0.074%, or at least 0.079%, or at least 0.084%, or at least 0.089%, or at least 0.094%, or at least 0.099%, or at least 0.104%, or at least 0.109%, or at least 0.114%, or at least 0.119%, or at least 0.124%, or at least 0.129%, or at least 0.134 %, or at least 0.139%, and / or at most 0.145%, or at most 0.140%, or at most 0.135%, or at most 0.130%, or at most 0.125%, or at most 0.120%, or at most 0.115%, or at most 0.110%, or at most 0.105%, or at most 0.100%, or at most 0.095%, or at most 0.090%, or at most 0.085%, or more or at most 0.080%, or at most 0.075%, or at most 0.070%, or at most 0.065%, or at most 0.060%, or at most 0.055%, or at most 0.050%, or at most 0.045%, or at most 0.040%, or at most 0.035%, or at most 0.030%, or at most 0.025%, or at most 0.020%, or at most 0.015%, or at most 0.010%.

[0034] The Mn content is at most 1.5% by weight. In an advantageous embodiment of the invention, the Mn content is between 0.03 and 1.0% by weight. In one embodiment, the Mn content is at least 0.05%, or at least 0.10%, or at least 0.15%, or at least 0.20%, or at least 0.25%, or at least 0.30%, or at least 0.35%, or at least 0.40%, or at least 0.45%, or at least 0.50%, or at least 0.55%, or at least 0.60%, or at least 0.65%, or at least 0.70%, or at least 0.75%, or at least 0.80%, or at least 0.85%, or at least 0.90%, or at least 0.95%, or at least 1.00%, or at least 1.05%, or at least 1.10%, or at least 1.15%, or at least 1.20%, or at least 1.25%, or at least 1.30%, or at least 1.3 5%, or at least 1.40%, and / or at most 1.45%, or at most 1.40%, or at most 1.35%, or at most 1.30%, or at most 1.25%, or at most 1.20%, or at most 1.15%, or at most 1.10%, or at most 1.05%, or at most 1.00%, or at most 0.95%, or at most 0.90%, or at most 0.85%, or at most 0.80%, or at most 0.75%, or at most 0.70%, or at most 0.65%, or at most 0.60%, or at most 0.55%, or at most 0.50%, or at most 0.45%, or at most 0.40%, or at most 0.35%, or at most 0.30%, or at most 0.25%, or at most 0.20%, or at most 0.15%, or at most 0.10%.

[0035] The V content is at most 0.20% by weight. In one embodiment of the present invention, the V content is 0.05 to 0.20% by weight. In one embodiment, the V content is at least 0.06%, or at least 0.07%, or at least 0.08%, or at least 0.09%, or at least 0.10%, or at least 0.11%, or at least 0.12%, or at least 0.13%, or at least 0.14%, or at least 0.15%, or at least 0.16%, or at least 0.17%, or at least 0.18%, and / or at most 0.19%, or at most 0.18%, or at most 0.17%, or at most 0.16%, or at most 0.15%, or at most 0.14%, or at most 0.13%, or at most 0.12%, or at most 0.11%, or at most 0.10%, or at most 0.09%, or at most 0.08%, or at most 0.07%.

[0036] 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 at least 0.10%, or at least 0.15%, or at least 0.20%, or at least 0.25%, or at least 0.30%, or at least 0.35%, or at least 0.40%, or at least 0.45%, or at least 0.50%, or at least 0.55%, or at least 0.60%, or at least 0.65%, or at least 0.70%, or at least 0.75%, or at least 0.80%, or at least 0.85%, or is at least 0.90%, and / or at most 0.95%, or at most 0.90%, or at most 0.85%, or at most 0.80%, or at most 0.75%, or at most 0.70%, or at most 0.65%, or at most 0.60%, or at most 0.55%, or at most 0.50%, or at most 0.45%, or at most 0.40%, or at most 0.35%, or at most 0.30%, or at most 0.25%, or at most 0.20%, or at most 0.15%, or at most 0.10%.

[0037] The Cr content is at most 0.25 wt%. In one embodiment, the Cr content is 0.01-0.25 wt%. In one embodiment, the Cr content is at least 0.02%, or at least 0.03%, or at least 0.04%, or at least 0.05%, or at least 0.06%, or at least 0.07%, or at least 0.08%, or at least 0.09%, or at least 0.10%, or at least 0.11%, or at least 0.12%, or at least 0.13%, or at least 0.14%, or at least 0.15%, or at least 0.16%, or at least 0.17%, or at least 0.18%, or at least 0.19%, or at least 0.20%, or at least 0.21%, or at least 0.22%. or at least 0.23%, and / or at most 0.24%, or at most 0.23%, or at most 0.22%, or at most 0.21%, or at most 0.20%, or at most 0.19%, or at most 0.18%, or at most 0.17%, or at most 0.16%, or at most 0.15%, or at most 0.14%, or at most 0.13%, or at most 0.12%, or at most 0.11%, or at most 0.10%, or at most 0.09%, or at most 0.08%, or at most 0.07%, or at most 0.06%, or at most 0.05%, or at most 0.04%, or at most 0.03%.

[0038] Other elements are unavoidable impurities, the content of which 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 should be understood that a maximum content is usually associated with each unavoidable impurity. Advantageously, the total of unavoidable impurities is at most 0.15% by weight, or at most 0.12%, or at most 0.10%, or at most 0.08%, or 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%.

[0039] The remainder is aluminum.

[0040] In one embodiment of the present invention, the alloy comprises at least two elements selected from Co, Ni, Ba, La, Ce, Ta, Ru, Os and Zr, the content of which, when selected, is between 0.003 and 0.15% by weight, the sum of the contents of the selected elements being at least equal to 0.08% by weight, and at least one of the selected elements having a content between 0.04 and 0.15% by weight, preferably between 0.05 and 0.10%.

[0041] In one embodiment of the present invention, the alloy comprises at least three elements selected from Co, Ni, Ba, La, Ce, Ta, Ru, Os and Zr, the contents of which, when selected, are between 0.003 and 0.15% by weight, the sum of the contents of the selected elements being at least equal to 0.14% by weight, and at least one of the selected elements having a content between 0.04 and 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.

[0042] The alloys of the present invention have the advantage of having a reduced average intermetallic particle distance and average intermetallic particle size compared to prior art alloys. Intermetallic particles are less detrimental, especially in forming, when they are small in size and slightly spaced apart. Thus, the alloys of the present invention are advantageous for reducing the time required for processes such as homogenization, improving forming-related properties such as elongation and formability, and improving surface properties such as anodization behavior.

[0043] The subject of the present invention is a heat-treated wrought product comprising the alloy according to the invention. In the context of the present invention, heat-treated products are to be understood as products of T temper, meaning heat-treated alloy products that have been heat-treated to obtain a stable state other than F, O or H. Typically, the heat-treated products are in T3, T4, T5, T6, T7 or T8 temper.

[0044] The subject of the present invention is a rolled product comprising an alloy according to the present invention. The rolled product according to the present invention typically has a thickness of 0.5 mm to 300 mm, preferably 0.8 mm to 150 mm. In an advantageous embodiment, the rolled product according to the present invention has a thickness of 0.8 mm to 1.5 mm and its bending angle α, measured according to the NF EN ISO 7438 standard and the procedures of VDA 238-100 and VDA 239-200, is m is at least 112°, preferably at least 114°.

[0045] Another subject of the invention is an extruded product comprising an alloy according to the invention. The extruded product according to the invention typically has a thickness of 0.5 mm to 30 mm, preferably 0.8 mm to 20 mm. Another subject of the invention is a wrought product comprising an alloy according to the invention. Typically, the wrought product according to the invention has a local thickness of 0.5 mm to 300 mm, preferably 0.8 mm to 150 mm.

[0046] The method making it possible to obtain a heat-treated wrought material according to the invention comprises the following steps: - providing pure or alloyed aluminium in the form of primary metal ingots derived from electrolysis and / or pre-consumer production scrap and / or post-consumer scrap, and additional elements in suitable forms, said scrap optionally being melted separately and possibly solidified; - forming a charge using the supplied aluminum, melting this charge and adding the additive elements to obtain a liquid alloy metal bath according to the invention; - casting said liquid metal bath, preferably by direct-cooled vertical semi-continuous casting, to obtain blanks suitable for hot working, typically rolled plates, forged blanks or billets, - homogenizing the blank at a temperature of at least 500°C; - hot working, by rolling, extrusion and / or forging, and optionally cold working, of the blank to obtain a wrought product, - solution treatment of the wrought material thus obtained at a temperature of at least 500°C and quenching; - ageing and / or tempering the solution-treated and quenched wrought material thus obtained at room temperature to obtain a heat-treated wrought material.

[0047] In a first step, pure or alloyed aluminium in the form of primary metal ingots derived from electrolysis and / or pre-consumer production scrap and / or post-consumer scrap, optionally melted and optionally solidified separately, and additional elements in suitable forms are provided.

[0048] Pure or alloyed aluminum in the form of primary metal ingots generally suffers from the drawback of generating significant CO2 emissions during its production, leading to efforts to limit its use. In this context, the term "ingot" refers to any form of solidified metal. For other metal sources, a distinction can be made between pre-consumer manufacturing scrap, which occurs before the metal reaches the end user (i.e., window buyer, vacuum chamber user, car buyer, airline, etc.), and post-consumer scrap, which is recovered after the product's use, typically in the scrap metal industry. The manufacturing process for aluminum products generates significant amounts of pre-consumer manufacturing scrap throughout the process. For example, this can consist of cast plate or melted billet offcuts trimmed before hot working, rolled or extruded product offcuts trimmed during the sheet metal or profile manufacturing process, blank skeletons used in stampings, machining shavings, etc. For example, post-consumer scrap consists of used window frames, car parts recovered from scrap cars, shredded automobiles, dismantled aircraft, etc. The post-consumer scrap can be supplied in compacted form or, optionally, separately melted and possibly solidified. The additive elements are also supplied in a suitable form. These can consist of elements in their metallic or alloyed form. For the addition of rare earth elements such as La, Ce, and Nd, it is advantageous to use mischmetal as the additive form.

[0049] In a subsequent step, all or part of the supplied aluminum is used to form a charge, which is melted and additional elements are added to obtain a liquid metal bath having a composition according to the invention, where it is possible that part of the supplied aluminum is already in liquid form.

[0050] The method according to the present invention is advantageous because it allows the use of a high proportion of production scrap and / or post-consumer scrap during the formation of the charge. Thus, in one embodiment, the charge comprises 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% production scrap. Thus, in one embodiment, the charge comprises 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% post-consumer scrap. Thus, in one embodiment, the charge comprises at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, or at least 80% production scrap and post-consumer scrap. The charge is then melted and its composition adjusted with additional elements to obtain a liquid metal bath having a composition according to the present invention.

[0051] 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 rolled plate or billet.

[0052] In a subsequent step, the blank thus obtained is homogenized at a temperature of at least 500°C. The homogenization time during which the entire blank reaches 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. In some embodiments, the alloy according to the invention allows for a shorter homogenization time. Thus, the homogenization time during which the entire blank reaches 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.

[0053] In a subsequent step, the thus homogenized blank is hot worked, and optionally cold worked, by rolling, extrusion, and / or forging to obtain a wrought product. Hot working typically begins at a temperature of at least 400°C. In one embodiment, the blank is cooled from the homogenization temperature to the working start temperature, optionally by forced cooling. In another embodiment, the blank is cooled to room temperature after homogenization and then reheated to reach the hot working start temperature.

[0054] In a subsequent step, the wrought material thus obtained is solution-treated at a temperature of at least 500°C and then quenched. Quenching is typically carried out in water by immersion or spraying, although for some products, especially extruded products, quenching in air may also be considered.

[0055] In an optional subsequent step, the wrought material thus solution treated and quenched may be cold worked and / or stress relieved.

[0056] In a subsequent step, the solution-treated and quenched wrought material thus obtained is aged and / or tempered at room temperature to obtain a heat-treated wrought material.

[0057] Applications of the present invention include, inter alia, automotive structures (e.g., body panels and reinforcements, impact absorption systems, battery boxes), building structures (e.g., frameworks, fittings, decorations, etc.), aircraft structures (e.g., fuselages, electrical connections, etc.), and industrial structures (e.g., steel towers, vacuum chambers, railway tracks). [Example]

[0058] In this example, an aluminum alloy part was cast and homogenized at 540°C for 8 hours. A refiner Al3Ti0.15C was added at a rate of 1 kg / t. The composition of the part is shown in Table 1 below.

[0059] [Table 1]

[0060] The intermetallic compound particles of the part are 3300 x 3300 μm 2 The samples were characterized by scanning electron microscopy over an area of ​​1000 nm. Two parameters, the average size of intermetallic particles and the average distance between intermetallic particles, were characterized by image analysis. The characterization method is illustrated in Figures 5, 6, and 7. The obtained intermetallic particle BSD (backscattered diffraction) images, such as those in Figure 5, are corrected and binarized (Figure 6), and the images undergo at least two successive steps of object closing to allow the size of intermetallic particles and the distance between intermetallic particles to be quantified (Figure 7). The image analysis closing steps are performed to measure the average size of intermetallic particles and the average distance between intermetallic particles.

[0061] The results, in % compared to the reference sample C1H, are presented in Table 2 and shown in Figure 1. In fact, it is more appropriate to present the results as percentages, as absolute values ​​may be affected by experimental parameters.

[0062] [Table 2]

[0063] Intermetallic particles are less harmful, especially for molding, if they are small in size and slightly separated from one another. In fact, these two parameters are correlated, and the total amount of intermetallic particles remains substantially constant across different tests, provided that the iron content in the test is constant. [Example]

[0064] In this example, an aluminum alloy part was cast and homogenized at 540°C for 8 hours. A refiner Al3Ti0.15C was added at a rate of 1 kg / t. The composition of the part is shown in Table 3 below.

[0065] [Table 3]

[0066] The intermetallic compound particles of the part are 3300 x 3300 μm 2 The intermetallic particles were characterized by scanning electron microscopy over an area of ​​1000 μm. Two parameters, the average size of the intermetallic particles and the average distance between the intermetallic particles, were characterized by image analysis.

[0067] The results, in % compared to the reference sample C16H, are presented in Table 4 and shown in Figure 2. In fact, it is more appropriate to present the results as percentages, as absolute values ​​may be affected by experimental parameters.

[0068] [Table 4]

[0069] Intermetallic particles are less harmful, especially for molding, if they are small in size and slightly separated from one another. In fact, these two parameters are correlated, and the total amount of intermetallic particles remains substantially constant across different tests, provided that the iron content in the test is constant. [Example]

[0070] In this example, an aluminum alloy part was cast and homogenized at 540°C for 8 hours. A refiner Al3Ti0.15C was added at a rate of 1 kg / t. The composition of the part is shown in Table 5 below.

[0071] [Table 5]

[0072] The intermetallic compound particles of the part are 3300 x 3300 μm 2 The intermetallic particles were characterized by scanning electron microscopy over an area of ​​1000 μm. Two parameters, the average size of the intermetallic particles and the average distance between the intermetallic particles, were characterized by image analysis.

[0073] The results, in % compared to the reference sample D4, are presented in Table 6 and shown in Figure 3. In fact, it is more appropriate to present the results as percentages, as the absolute values ​​may be affected by experimental parameters.

[0074] [Table 6] [Example]

[0075] In this example, an aluminum alloy part was cast and homogenized at 540°C for 8 hours. A refiner Al3Ti0.15C was added at a rate of 1 kg / t. The composition of the part is shown in Table 7 below.

[0076] [Table 7]

[0077] The intermetallic compound particles of the part are 3300 x 3300 μm 2 The intermetallic particles were characterized by scanning electron microscopy over an area of ​​1000 μm. Two parameters, the average size of the intermetallic particles and the average distance between the intermetallic particles, were characterized by image analysis.

[0078] The results, in % compared to the reference sample D5, are presented in Table 8 and shown in Figure 4. In fact, it is more appropriate to present the results as percentages, as the absolute values ​​may be affected by experimental parameters.

[0079] [Table 8]

[0080] Intermetallic particles are less harmful, especially for molding, if they are small in size and slightly separated from one another. In fact, these two parameters are correlated, and the total amount of intermetallic particles remains substantially constant across different tests, provided that the iron content in the test is constant. [Example]

[0081] In this example, parts were cast from aluminum alloy 6082 with the addition of 1 wt. % iron and, in one test, 0.2 wt. % La.

[0082] The intermetallic particles of the parts were characterized by optical microscopy. The results are shown in Figure 8 with and without the addition of La. The intermetallic particles have a smaller size in the case of the addition of La, and their distribution is improved by 35% compared to the reference without La. [Example]

[0083] In this example, industrial-format plates were cast from aluminum alloy. A refiner, Al3Ti0.15C, was added at a rate of 1 kg / t. The composition of the plates is shown in Table 9 below. The three alloys comply with the registration of alloy AA6016A, but the iron content of alloy E1 is typical of the standard industrial content, while the iron content of alloys E2 and E3 is typical of alloys with a high level of recycled material.

[0084] [Table 9]

[0085] The plates were homogenized at 560°C for 3 hours and then at 535°C for 1 hour, and then hot-rolled and cold-rolled to obtain sheets with a thickness of 1.2 mm.

[0086] Sheets with a thickness of 1.2 mm were solution treated at 520°C for 1 hour, quenched, pre-tempered at 85°C for 8 hours and aged at room temperature for 21 days. The mechanical performance of these sheets in bending tests according to the NF EN ISO7438 standard and the procedures of VDA238-100 and VDA239-200 was characterized transverse to the rolling direction and after a pre-stretch of 14% in this direction.

[0087] The results obtained are shown in Table 10.

[0088] [Table 10]

[0089] The addition of Co and Zr can restore the bending performance of the AA6016A alloy with a high iron content to that of the AA6016A alloy with a standard iron content.

Claims

1. In weight percent, - Mg: 0.2 to 1.5, - Si: 0.3 to 2.0, - Fe: 0.30 to 1.0, - Ti: 0.01 to 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 which, if selected, is between 0.003 and 0.20, preferably between 0.005 and 0.15; - Zr:≦0.15, - Mn: ≦1.5, - V: ≦0.20, Zn: ≦1.0, - Cr:≦0.25, Cu: ≦1.5, Including, the remainder being aluminum and unavoidable impurities with a content of at most 0.05% by weight; Aluminum-based alloy.

2. 2. The alloy of claim 1 comprising, in wt. %: 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.

3. 3. The alloy according to claim 1 or 2, wherein the alloy comprises at least two elements selected from among Co, Ni, Ba, La, Ce, Ta, Ru, Os and Zr with a content of the element, when selected, between 0.003 and 0.15% by weight, the sum of the contents of the selected elements being at least equal to 0.08% by weight, and at least one of the selected elements having a content between 0.04 and 0.15% by weight.

4. 4. The alloy according to any one of claims 1 to 3, wherein the alloy comprises at least three elements selected from among Co, Ni, Ba, La, Ce, Ta, Ru, Os and Zr with a content of the elements, when selected, between 0.003 and 0.15% by weight, the sum of the contents of the selected elements being at least equal to 0.14% by weight, and at least one of the selected elements having a content between 0.04 and 0.15% by weight.

5. 5. The alloy of claim 4, wherein the selected elements are Co, Ba, Zr, or Ni, Ba, Zr, or Co, La, Zr, or Co, Ni, Ba.

6. An alloy according to any one of claims 1 to 5, wherein the Fe content is between 0.35 and 0.85 wt.%, preferably between 0.4 and 0.7 wt.%.

7. A heat treated wrought product comprising the alloy of any one of claims 1 to 6.

8. 8. The wrought material according to claim 7, wherein the wrought material is a rolled product having a thickness of 0.5 mm to 300 mm, preferably 0.8 mm to 150 mm.

9. The thickness is between 0.8 mm and 1.5 mm, and the bending angle α measured according to the NF EN ISO 7438 standard and the procedures of VDA 238-100 and VDA 239-200 ｍ 9. Wrought material according to claim 8, characterized in that the angle is at least 112°, preferably at least 114°.

10. 8. The wrought material according to claim 7, wherein the wrought material is an extruded product having a thickness of 0.5 mm to 30 mm, preferably 0.8 mm to 20 mm.

11. 8. Wrought material according to claim 7, wherein the wrought material is a forged product having a thickness locally between 0.5 mm and 300 mm, preferably between 0.8 mm and 150 mm.

12. A method for producing an expanded material according to any one of claims 7 to 11, comprising the following steps: - providing pure or alloyed aluminium in the form of primary metal ingots derived from electrolysis and / or pre-consumer production scrap and / or post-consumer scrap, and additional elements in suitable forms, said scrap optionally being melted separately and possibly solidified; forming a charge using the aluminum provided, melting this charge and adding the additional elements to obtain a liquid alloy metal bath according to the invention; - casting said liquid metal bath, preferably by vertical semi-continuous casting with direct cooling, to obtain blanks suitable for hot working, typically rolled plates, forged blanks or billets; homogenizing the blank at a temperature of at least 500°C; hot working, by rolling, extrusion and / or forging, and optionally cold working, of the blank to obtain a wrought product; - solution treatment of the wrought material thus obtained at a temperature of at least 500°C and quenching; - ageing and / or tempering the solution-treated and quenched wrought material thus obtained at room temperature to obtain a heat-treated wrought material; A manufacturing method comprising:

13. 13. The method of claim 12, wherein the charge comprises at least 30% post-consumer scrap.

14. 14. The method of claim 12 or 13, wherein titanium is added in the form of metallic titanium and TiC.

15. Use of the wrought material according to any one of claims 7 to 11 for automotive, architectural, aircraft or industrial structures.

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