Recyclable aluminum alloy and manufacturing method

Abstract

The present invention relates to an aluminum alloy having the following composition in weight percent: Si: about 1.7% to about 7.0%, Fe: about 0.3% to about 0.5%, Cu: about 0.3% to about 1.0%, Mn: about 0.2% to about 0.6%, Mg: about 0.2% to about 0.6%, Zn: about 0.2% to about 0.6%, Ti, Cr, Sn, Pb, Zr, V, Sr, Ni: ≤ about 0.1%, other elements: ≤ 0.05% each, total ≤ 0.15%, remainder: Al. The present invention also relates to rolled products of the alloy according to the present invention. The alloy according to the present invention is particularly suitable for recycling and preferably contains at least 20% post-consumer waste, preferably from end-of-life vehicles, more preferably from aluminum twich shredded by an auto shredder.

Description

[Technical Field]

[0001] This invention relates to the field of aluminum alloys for the purpose of manufacturing automotive parts made from recycled products. [Background technology]

[0002] Aluminum alloys are increasingly being used in automobile manufacturing to reduce vehicle weight, and consequently, to improve fuel efficiency and reduce greenhouse gas emissions.

[0003] Typically, aluminum alloys used in automobile manufacturing are recycled into cast parts, particularly engine components. However, the evolution of automobile propulsion from internal combustion engines to electric motors will likely eliminate this recycling pathway.

[0004] Therefore, in order to reduce the CO2 equivalent emissions from automobile manufacturing, manufacturers need to increase their use of recycled products, which is further increasing the demand for aluminum alloys made from recycled materials.

[0005] U.S. Patent Application Publication No. 2021 / 0108293 discloses an aluminum alloy sheet having a chemical composition comprising Si: 2.3–3.8 mass%, Mn: 0.35–1.05 mass%, Mg: 0.35–0.65 mass%, Fe: 0.01–0.45 mass%, and at least one element selected from the group consisting of Cu: 0.0010–1.0 mass%, Cr: 0.0010–0.10 mass%, Zn: 0.0010–0.50 mass%, and Ti: 0.0050–0.20 mass%. The ratio of Si content to Mn content is between 2.5 and 9.0. The aluminum alloy sheet exhibits a work hardening index of 0.28 or higher and an elongation of 23% or higher at a nominal strain of 3%. Such an aluminum alloy sheet is very suitable for press forming (stamping) applications, such as forming automobile body panels.

[0006] International Publication No. 2018 / 175876 discloses a technique for casting high-strength, formable metal products from recycled metal scrap with substantially or no addition of primary aluminum. By adding alloying elements such as magnesium to the metal scrap, casting and processing can be performed to produce desired metal coils of a desired final thickness with desirable metallurgical and mechanical properties such as high strength and formability. In this way, inexpensive recycled metal scrap can be efficiently reused for new applications such as automotive applications and beverage can raw materials.

[0007] Japanese Patent Publication No. 2005-298922 addresses the challenge of providing a low-cost aluminum alloy sheet for forming that has sufficient hem-bending workability, low bending anisotropy, excellent paint-baking hardening properties, low deterioration over time at room temperature, and sufficient rionic mark resistance. The solution is to use an Al-Mg-Si alloy or an Al-Mg-Si-Cu alloy, (C 1 / 10 +C 1 / 4 ) / 2>C 1 / 2 and 30<(C 1 / 10 +C 1 / 4 )<500 is an aluminum alloy plate that satisfies each of the conditions, where C 1 / 10 , C 1 / 4 , C 1 / 2 This is defined as the cube orientation density at depths of 1 / 10, 1 / 4, and 1 / 2 of the plate thickness from the plate surface. Also, {001} is defined as the region of depth from 1 / 10 to 1 / 4 in the plate thickness direction. <210> The orientation density is within the range of 2 to 50, and the ear ratios at 0° and 90° are 5% or more. The manufacturing method includes strictly defined casting and hot rolling conditions. The microstructure conditions for intermediate products, namely cast slabs and hot-rolled plates, are specified.

[0008] International Publication No. 2022 / 026825 discloses a novel 6xxx aluminum alloy. One approach is to provide a novel 6xxx aluminum alloy containing 0.25–0.60 wt% Fe, 0.8–1.2 wt% Si, 0.35–1.1 wt% Mg, 0.05–0.8 wt% Mn, up to 0.30 wt% Cu, up to 0.35 wt% Zn, up to 0.15 wt% Ti, and up to 0.15 wt% each of Cr, Zr, and V, with the remainder being aluminum, associated elements, and impurities. The novel 6xxx aluminum alloy can be produced from recycled aluminum alloys.

[0009] International Publication No. 99 / 60181 discloses an aluminum sheet for automobiles having an aluminum alloy composition comprising 3.5 to 5 wt% Si, 0.3 to 1.5 wt% Mg, 0.4 to 1.5 wt% Zn, 0.4 to 1.5 wt% Cu, 0.4 to 1.5 wt% Fe, and 0.6 to 1 wt% Mn, and further comprising one or more of 0.01 to 0.2 wt% Cr, 0.01 to 0.2 wt% Ti, 0.01 to 0.2 wt% Zr, and 0.01 to 0.2 wt% V, with the remainder of the composition being aluminum and unavoidable impurities.

[0010] Japanese Patent Publication No. 2000-063972 discloses an extruded aluminum alloy containing 2.6% to 4.0% by weight of Si, more than 0.3% by weight and less than or equal to 1.5% by weight of Mg, more than 0.3% by weight and less than or equal to 1.2% by weight of Zn, more than 0.3% by weight and less than or equal to 1.2% by weight of Cu, and more than 0.1% by weight and less than or equal to 1.5% by weight of Fe, and further containing more than 0.01% by weight and less than or equal to 0.3% by weight of Mn, more than 0.01% by weight and less than or equal to 0.3% by weight of Cr, more than 0.01% by weight and less than or equal to 0.3% by weight of Zr, and more than 0.01% by weight and less than or equal to 0.3% by weight of V, with the remainder being Al and unavoidable impurities, wherein the electrical conductivity is 50% IACS or less and the melting onset temperature is 570°C or less.

[0011] U.S. Patent No. 6,607,615 discloses an aluminum alloy extruded material for structural components of an automobile body, which is made of an aluminum alloy that contains more than 2.6% by weight but no more than 4.0% by weight of Si and more than 0.3% by weight but no more than 1.5% by weight of Mg, and further contains (i) predetermined amounts of Mn, Zn, Cu, and Fe, or (ii) predetermined amounts of Zn, Cu, and Fe, and a predetermined amount of at least one element selected from Mn, Cr, Zr, and V, with the remainder being Al and unavoidable impurities, and the material has a predetermined electrical conductivity and a predetermined melting onset temperature.

[0012] U.S. Patent No. 6,325,870 describes a material containing (i) 3.5 to 5 wt% Si, 0.3 to 1.5 wt% Mg, 0.4 to 1.5 wt% Zn, 0.4 to 1.5 wt% Cu, 0.4 to 1.5 wt% Fe, and 0.6 to 1 wt% Mn, and one or more elements selected from the group consisting of 0.01 to 0.2 wt% Cr, 0.01 to 0.2 wt% Ti, 0.01 to 0.2 wt% Zr, and 0.01 to 0.2 wt% V, with the remainder being aluminum and unavoidable impurities, or (ii) more than 2.6 wt% ~ 5 This invention discloses an aluminum sheet material for automobiles having an aluminum alloy composition containing wt% Si, 0.2 to 1.0 wt% Mg, 0.2 to 1.5 wt% Zn, 0.2 to 1.5 wt% Cu, 0.2 to 1.5 wt% Fe, and 0.05 to less than 0.6 wt% Mn, as well as one or more elements selected from the group consisting of 0.01 to 0.2 wt% Cr, 0.01 to 0.2 wt% Ti, 0.01 to 0.2 wt% Zr, and 0.01 to 0.2 wt% V, with the remainder being aluminum and unavoidable impurities. By using recycled aluminum material, it is possible to manufacture an aluminum sheet for automobiles that has excellent mechanical strength and bending properties, as well as improved weldability.

[0013] U.S. Patent No. 6,355,090 discloses an aluminum alloy comprising 0.5 to 5.0 wt% Si, 0.2 to 5.0 wt% Mg, 0.01 to 1.2 wt% Mn, 0.1 to 1.2 wt% Zn, 0.2 to 1.2 wt% Cu, 0.2 to 2.0 wt% Fe, and one or more of the following elements: 0.01 to 0.2 wt% Cr, 0.01 to 0.2 wt% Zr, 0.01 to 0.2 wt% V, and 0.01 to 0.2 wt% Ti, with the remainder being Al and unavoidable impurities.

[0014] However, recycled alloys are only meaningful if they can make use of large quantities of waste, especially waste from end-of-life vehicles. Typically, end-of-life vehicles are crushed, and then various separation methods known to those skilled in the art are carried out to sort out the products obtained by the crushing. One of the products obtained by the said separation is twitch, and its typical composition is shown in Table 2.

[0015] Therefore, in order to produce body panels with properties suitable for use in vehicles for the automotive industry, it is necessary to recycle scrap and waste in the form of twitch. [Prior art documents] [Patent Documents]

[0016] [Patent Document 1] U.S. Patent Application Publication No. 2021 / 0108293 [Patent Document 2] International Publication No. 2018 / 175876 [Patent Document 3] Japanese Patent Publication No. 2005-298922 [Patent Document 4] International Publication No. 2022 / 026825 [Patent Document 5] International Publication No. 99 / 60181 [Patent Document 6] Japanese Patent Publication No. 2000-063972 [Patent Document 7] U.S. Patent No. 6607615

Patent Document 8

Patent Document 9

Summary of the Invention

Problems to be Solved by the Invention

[0017] [Problems Raised] The problem to be solved is to develop an aluminum alloy that maximally utilizes post-consumer waste in twitch while aiming for an excellent compromise among mechanical strength, formability, corrosion resistance, and manufacturing suitability.

[0018] Actually, in order to obtain the same springback during forming, it is necessary to obtain an alloy with a yield strength (Rp0.2) similar to that of the currently used alloy. In order to manufacture equivalent parts, the alloy must have at least the same Ag% elongation as the currently used alloy, preferably at least 20%. In order to obtain the same, preferably higher, mechanical performance in a vehicle, after bake hardening, the alloy must have a yield strength (Rp0.2) equivalent to that of the currently used alloy. The corrosion behavior must be at least equivalent to that of the currently used alloy. Examples of currently used alloys include the following Examples J, K, and L.

Means for Solving the Problems

[0019] [Subject of the Present Invention] The first subject of the present invention is, by weight%, Si: about 1.7% to about 7.0%, Fe: about 0.2% to about 0.8%, Cu: about 0.3% to about 1.0%, Mn: about 0.2% to about 0.6%, Mg: about 0.2% to about 0.6%, Zn: about 0.2% to about 0.6%, Ti, Cr, Sn, Pb, Zr, V, Sr, Ni: about 0.1% or less, Other elements: 0.05% or less each, 0.15% or less total. Remainder: Al It is an aluminum alloy having the following composition.

[0020] A second object of the present invention is a rolled product of the alloy according to the present invention.

[0021] A third aspect of the present invention relates to the following sequence of steps: a) A supply of aluminum alloy and additive metals, wherein the aluminum alloy is in the form of at least 20% post-consumer waste, b) Optionally, sorting of post-consumer waste, c) Optionally, smelting of the alloy according to any one of claims 1 to 8 from an aluminum alloy containing sorted post-consumer waste and supplied additive metals. d) Preferably casting of the alloy into the base metal by semi-continuous vertical casting. e) Homogenization and / or reheating of the metal, f) Hot deformation and optionally cold deformation due to rolling of the metal, g) Solution treatment of the metal processed in this manner, followed by quenching, h) Optionally, a preliminary aging period of 1 to 24 hours, typically at a preliminary aging temperature of 60 to 120°C. i) Preferably, natural aging, ranging from 24 hours to 6 months. This is a method for manufacturing a product according to the present invention, which includes [the specified element].

[0022] A fourth aspect of the present invention is the use of the product according to the present invention for manufacturing automotive parts. [Brief explanation of the drawing]

[0023] [Figure 1] This figure shows LDH as a function of recyclability. [Figure 2] This figure shows the Ag% elongation for each T4 quality as a function of cracking tendency (cracking properties) during cold rolling. [Figure 3]It is a diagram showing the compromise point between LDH and yield strength by T4 quality. [Figure 4] It is a diagram showing a tool for measuring LDH. [Figure 5] It is a diagram showing the work hardening coefficient as a function of recyclability.

Mode for Carrying Out the Invention

[0024] All of the following aluminum alloys in this case are named according to the rules and names defined in the "Registration Record Series" regularly issued by the "Aluminum Association", unless otherwise specified. Unless otherwise specified, the composition is expressed in weight%. The expression 1.4Cu means that the copper content expressed in weight% is 1.4%. The group of alloys, also called the series, is defined in EN573-1(2005).

[0025] The metallurgical quality in this case is specified according to European standard EN515. In particular, solution-treated and quenched quality products are known to those skilled in the art as those obtained by heating the alloy at a specific temperature for a sufficiently long time to allow one or more components to enter the solid solution and maintaining a supersaturated quality even after quenching. In particular, aged products are known to those skilled in the art as those obtained by a metal treatment aimed at changing the properties of the metal by precipitating intermetallic phases from a supersaturated solution. Aging can be achieved by heat treatment (aging or artificial aging) or at room temperature (natural aging). The pre-aged quality is not standardized in this standard but is well known to those skilled in the art and is sometimes designated as T4p or T4 * This is a heat treatment after quenching that stabilizes the product by suppressing natural aging while improving the responsiveness of the product during paint baking, which is aging in metallurgical terms.

[0026] The static tensile mechanical properties, namely tensile strength Rm, conventional yield strength Rp0.2% at 0.2% elongation, uniform elongation Ag%, and fracture elongation A%, are determined by tensile testing in accordance with NF EN ISO6892-1, with the sampling and direction of the tests defined in EN485-1.

[0027] The bending angle, known as alpha, is determined by a three-point bending test in accordance with NF EN ISO7438 and procedures VDA238-100 and VDA239-200, 2017 edition.

[0028] Unless otherwise specified, the definitions in EN12258 shall apply.

[0029] The LDH parameter is widely used to evaluate the stamping suitability of sheet metal. It has been the subject of numerous publications, particularly R. Thompson's "The LDH test to evaluate sheet metal formability - Final Report of the LDH Committee of the North American Deep Drawing Research Group," SAE conference, Detroit, 1993, SAE Paper no. 930815. This is an example of a test on stamping a blank with its periphery secured by a ring. The clamping pressure of the blank is adjusted to prevent slippage within the ring. A blank measuring 120mm x 160mm is subjected to stress in a mode close to planar deformation. The punch used is hemispherical. Figure 4 shows the dimensions of the tools used to perform this test. Lubrication between the punch and the sheet metal is provided by graphite grease. The punch descends at a speed of 50mm / min. The so-called LDH value is the punch's movement at fracture, i.e., the limiting depth of stamping. This actually corresponds to the average of three tests and gives a 95% confidence interval for a 0.2 mm measurement.

[0030] The tensile work hardening coefficient is measured according to the ISO 10275 2020-08 standard.

[0031] Unless otherwise specified, the definitions in the EN12258-1(1998) standard shall apply.

[0032] Unless otherwise specified, the definitions in the EN12258-3(2003) standard shall apply.

[0033] Pure or alloyed aluminum in the form of primary metal ingots generally has the disadvantage of generating large amounts of CO2 emissions during its manufacture, and therefore efforts are being made to limit its use. Regarding other metal sources, pre-consumer manufacturing scrap, generated before the metal is delivered to end customers such as window buyers, vacuum chamber users, automobile buyers, and airlines, can be distinguished from post-consumer waste, which is recovered after the product's use, typically at end-of-life vehicles in sorting centers. The manufacturing process of aluminum products generates a large amount of pre-consumer manufacturing scrap throughout the entire process. For example, this may consist of offcuts of cast plates trimmed before hot working, offcuts of rolled and extruded parts trimmed during the manufacturing process of sheet metal and profiles, blank frameworks used for stamping, and shavings from machining. Post-consumer waste, for example, consists of used window frames, automobile parts recovered from end-of-life vehicles, shredded automobiles, and dismantled airplanes. Post-consumer waste may be supplied in a compressed, unprocessed form, or optionally melted separately and solidified. Appropriate forms of additive elements are also supplied. The elements may consist of metallic or alloying elements.

[0034] Unless otherwise specified, the definitions of the ISRI (American Society for the Recycling of Resources) "Scrap Specification Circular 2022" apply. Specifically, twitch is defined as aluminum waste or scrap that has been broken down by an auto shredder.

[0035] The twitch is obtained from a wet or dry media separator, and the material is dry and free of more than 1% free zinc, more than 1% free magnesium, and more than 1% analytical iron. It does not contain more than 2% nonmetallic material in total, and more than 1% rubber and plastic. It does not contain excessively oxidized material, airbag cartridges, or any sealed or pressurized articles.

[0036] Room temperature is a temperature suitable for human work, ranging from 5 to 35°C. Room temperature can be 5°C, 6°C, 7°C, 8°C, 9°C, 10°C, 11°C, 12°C, 13°C, 14°C, 15°C, 16°C, 17°C, 18°C, 19°C, 20°C, 21°C, 22°C, 23°C, 24°C, 25°C, 26°C, 27°C, 28°C, 29°C, 30°C, 31°C, 32°C, 33°C, 34°C, or 35°C.

[0037] When used in relation to a measurable numerical variable, the term "approximately" refers to the indicated value of that variable and all values ​​of that variable that are within the experimental error limits of that indicated value or within ±10 percent of that indicated value, with the maximum value being retained.

[0038] [Detailed explanation] This invention is based on the observation made by the applicant that it is absolutely possible to produce sheet metal from recycled aluminum post-consumer waste having acceptable stamping properties, good corrosion resistance, and mechanical properties particularly suitable for the manufacture of automobile bodies, thanks to appropriate composition and manufacturing processes.

[0039] Therefore, the concentration range imposed on the constituent elements of this type of alloy can be explained by the following reasons.

[0040] Si: Si content is approximately 1.7% to 7.0%. Increasing the Si content facilitates the use of recycled products, especially twich. Mg2Si or Mg5Si6 precipitates contribute to the hardening of the alloy during aging, for example, during paint baking. Excess Si reduces hot and cold rolling suitability by causing edge cracks that reduce the usable width of the rolled sheet, or even causing breakage during manufacturing. Excess Si relative to Mg contributes to formability in T4 temper. Si contributes to strain rate sensitivity.

[0041] A compromise between recycling and these properties is favorably reached when Si ≥ 2.0%, preferably Si ≥ 2.2%, more preferably Si ≥ 2.5%, more preferably Si ≥ 2.8%, and / or Si ≤ 6%, preferably Si ≤ 5%, more preferably Si ≤ 4.3%, and more preferably Si ≤ 4.1%.

[0042] In one embodiment, the mass content of Si is at least about 1.90%, and at most about 2.10%, or at most about 2.30%, or at most about 2.50%, or at most about 2.70%, or at most about 2.90%, or at most about 3.10%, or at most about 3.30%, or at most about 3.50%, or at most about 3.70%, or at most about 3.90%, or at most about 4.10%, or at most about 4.30%, or at most about 4.50%, or at most about 4.70%, or at most about 4.90%, or at most about 5.10%, or at most about 5.30%, or at most about 5.50%, or at most about 5.70%, or at most about 5.90%, or at most about 6.10%, or at most about 6.30%, or at most about 6.50%, or at most about 6.70%.

[0043] In one embodiment, the mass content of Si is at least about 2.10%, and at most about 2.30%, or at most about 2.50%, or at most about 2.70%, or at most about 2.90%, or at most about 3.10%, or at most about 3.30%, or at most about 3.50%, or at most about 3.70%, or at most about 3.90%, or at most about 4.10%, or at most about 4.30%, or at most about 4.50%, or at most about 4.70%, or at most about 4.90%, or at most about 5.10%, or at most about 5.30%, or at most about 5.50%, or at most about 5.70%, or at most about 5.90%, or at most about 6.10%, or at most about 6.30%, or at most about 6.50%, or at most about 6.70%.

[0044] In one embodiment, the mass content of Si is at least about 2.30%, and at most about 2.50%, or at most about 2.70%, or at most about 2.90%, or at most about 3.10%, or at most about 3.30%, or at most about 3.50%, or at most about 3.70%, or at most about 3.90%, or at most about 4.10%, or at most about 4.30%, or at most about 4.50%, or at most about 4.70%, or at most about 4.90%, or at most about 5.10%, or at most about 5.30%, or at most about 5.50%, or at most about 5.70%, or at most about 5.90%, or at most about 6.10%, or at most about 6.30%, or at most about 6.50%, or at most about 6.70%.

[0045] In one embodiment, the mass content of Si is at least about 2.50%, and at most about 2.70%, or at most about 2.90%, or at most about 3.10%, or at most about 3.30%, or at most about 3.50%, or at most about 3.70%, or at most about 3.90%, or at most about 4.10%, or at most about 4.30%, or at most about 4.50%, or at most about 4.70%, or at most about 4.90%, or at most about 5.10%, or at most about 5.30%, or at most about 5.50%, or at most about 5.70%, or at most about 5.90%, or at most about 6.10%, or at most about 6.30%, or at most about 6.50%, or at most about 6.70%.

[0046] In one embodiment, the mass content of Si is at least about 2.70%, and at most about 2.90%, or at most about 3.10%, or at most about 3.30%, or at most about 3.50%, or at most about 3.70%, or at most about 3.90%, or at most about 4.10%, or at most about 4.30%, or at most about 4.50%, or at most about 4.70%, or at most about 4.90%, or at most about 5.10%, or at most about 5.30%, or at most about 5.50%, or at most about 5.70%, or at most about 5.90%, or at most about 6.10%, or at most about 6.30%, or at most about 6.50%, or at most about 6.70%.

[0047] In one embodiment, the mass content of Si is at least about 2.90%, and at most about 3.10%, or at most about 3.30%, or at most about 3.50%, or at most about 3.70%, or at most about 3.90%, or at most about 4.10%, or at most about 4.30%, or at most about 4.50%, or at most about 4.70%, or at most about 4.90%, or at most about 5.10%, or at most about 5.30%, or at most about 5.50%, or at most about 5.70%, or at most about 5.90%, or at most about 6.10%, or at most about 6.30%, or at most about 6.50%, or at most about 6.70%.

[0048] In one embodiment, the mass content of Si is at least about 3.10%, and at most about 3.30%, or at most about 3.50%, or at most about 3.70%, or at most about 3.90%, or at most about 4.10%, or at most about 4.30%, or at most about 4.50%, or at most about 4.70%, or at most about 4.90%, or at most about 5.10%, or at most about 5.30%, or at most about 5.50%, or at most about 5.70%, or at most about 5.90%, or at most about 6.10%, or at most about 6.30%, or at most about 6.50%, or at most about 6.70%.

[0049] In one embodiment, the mass content of Si is at least about 3.30%, and at most about 3.50%, or at most about 3.70%, or at most about 3.90%, or at most about 4.10%, or at most about 4.30%, or at most about 4.50%, or at most about 4.70%, or at most about 4.90%, or at most about 5.10%, or at most about 5.30%, or at most about 5.50%, or at most about 5.70%, or at most about 5.90%, or at most about 6.10%, or at most about 6.30%, or at most about 6.50%, or at most about 6.70%.

[0050] In one embodiment, the mass content of Si is at least about 3.50%, and at most about 3.70%, or at most about 3.90%, or at most about 4.10%, or at most about 4.30%, or at most about 4.50%, or at most about 4.70%, or at most about 4.90%, or at most about 5.10%, or at most about 5.30%, or at most about 5.50%, or at most about 5.70%, or at most about 5.90%, or at most about 6.10%, or at most about 6.30%, or at most about 6.50%, or at most about 6.70%.

[0051] In one embodiment, the mass content of Si is at least about 3.70%, and at most about 3.90%, or at most about 4.10%, or at most about 4.30%, or at most about 4.50%, or at most about 4.70%, or at most about 4.90%, or at most about 5.10%, or at most about 5.30%, or at most about 5.50%, or at most about 5.70%, or at most about 5.90%, or at most about 6.10%, or at most about 6.30%, or at most about 6.50%, or at most about 6.70%.

[0052] In one embodiment, the mass content of Si is at least about 3.90%, and at most about 4.10%, or at most about 4.30%, or at most about 4.50%, or at most about 4.70%, or at most about 4.90%, or at most about 5.10%, or at most about 5.30%, or at most about 5.50%, or at most about 5.70%, or at most about 5.90%, or at most about 6.10%, or at most about 6.30%, or at most about 6.50%, or at most about 6.70%.

[0053] In one embodiment, the mass content of Si is at least about 4.10%, and at most about 4.30%, or at most about 4.50%, or at most about 4.70%, or at most about 4.90%, or at most about 5.10%, or at most about 5.30%, or at most about 5.50%, or at most about 5.70%, or at most about 5.90%, or at most about 6.10%, or at most about 6.30%, or at most about 6.50%, or at most about 6.70%.

[0054] In one embodiment, the mass content of Si is at least about 4.30%, and at most about 4.50%, or at most about 4.70%, or at most about 4.90%, or at most about 5.10%, or at most about 5.30%, or at most about 5.50%, or at most about 5.70%, or at most about 5.90%, or at most about 6.10%, or at most about 6.30%, or at most about 6.50%, or at most about 6.70%.

[0055] In one embodiment, the mass content of Si is at least about 4.50%, and at most about 4.70%, or at most about 4.90%, or at most about 5.10%, or at most about 5.30%, or at most about 5.50%, or at most about 5.70%, or at most about 5.90%, or at most about 6.10%, or at most about 6.30%, or at most about 6.50%, or at most about 6.70%.

[0056] In one embodiment, the mass content of Si is at least about 4.70%, and at most about 4.90%, or at most about 5.10%, or at most about 5.30%, or at most about 5.50%, or at most about 5.70%, or at most about 5.90%, or at most about 6.10%, or at most about 6.30%, or at most about 6.50%, or at most about 6.70%.

[0057] In one embodiment, the mass content of Si is at least about 4.90%, and at most about 5.10%, or at most about 5.30%, or at most about 5.50%, or at most about 5.70%, or at most about 5.90%, or at most about 6.10%, or at most about 6.30%, or at most about 6.50%, or at most about 6.70%.

[0058] In one embodiment, the mass content of Si is at least about 5.10%, and at most about 5.30%, or at most about 5.50%, or at most about 5.70%, or at most about 5.90%, or at most about 6.10%, or at most about 6.30%, or at most about 6.50%, or at most about 6.70%.

[0059] In one embodiment, the mass content of Si is at least about 5.30%, and at most about 5.50%, or at most about 5.70%, or at most about 5.90%, or at most about 6.10%, or at most about 6.30%, or at most about 6.50%, or at most about 6.70%.

[0060] In one embodiment, the mass content of Si is at least about 5.50%, and at most about 5.70%, or at most about 5.90%, or at most about 6.10%, or at most about 6.30%, or at most about 6.50%, or at most about 6.70%.

[0061] In one embodiment, the Si mass content is at least about 5.70%, and at most about 5.90%, or at most about 6.10%, or at most about 6.30%, or at most about 6.50%, or at most about 6.70%.

[0062] In one embodiment, the Si mass content is at least about 5.90%, and at most about 6.10%, or at most about 6.30%, or at most about 6.50%, or at most about 6.70%.

[0063] In one embodiment, the mass content of Si is at least about 6.10%, and at most about 6.30%, or at most about 6.50%, or at most about 6.70%. In one embodiment, the mass content of Si is at least about 6.30%, and at most about 6.50%, or at most about 6.70%. In one embodiment, the mass content of Si is at least about 6.50%, and at most about 6.70%.

[0064] Fe: The Fe content is approximately 0.2% to 0.8%. Since Fe is a contaminant in the recycling process, increasing the Fe content makes it easier to use recycled products. If the Fe content is very low, the product to be recycled will need to be diluted with a more expensive alloy with a lower Fe content. Fe reduces the hot and cold rolling suitability by causing edge cracks that reduce the usable width of the rolled sheet, or even causing breakage during manufacturing. Excess Fe can make the product unsuitable for forming, especially because it can reduce bendability.

[0065] A compromise between recycling and these properties is favorably reached when Fe ≥ 0.25%, preferably Fe ≥ 0.30%, more preferably Fe ≥ 0.33%, more preferably Fe ≥ 0.35%, more preferably Fe ≥ 0.37%, and / or Fe ≤ 0.75%, preferably Fe ≤ 0.65%, more preferably Fe ≤ 0.55%, more preferably Fe ≤ 0.50%, and more preferably Fe ≤ 0.45%.

[0066] In one embodiment, the mass content of Fe is at least about 0.20%, and at most about 0.30%, or at most about 0.40%, or at most about 0.50%, or at most about 0.60%, or at most about 0.70%, or at most about 0.80%. In one embodiment, the mass content of Fe is at least about 0.30%, and at most about 0.40%, or at most about 0.50%, or at most about 0.60%, or at most about 0.70%, or at most about 0.80%. In one embodiment, the mass content of Fe is at least about 0.40%, and at most about 0.50%, or at most about 0.60%, or at most about 0.70%, or at most about 0.80%. In one embodiment, the mass content of Fe is at least about 0.50%, and at most about 0.60%, or at most about 0.70%, or at most about 0.80%. In one embodiment, the mass content of Fe is at least about 0.60% and at most about 0.70% or at most about 0.80%.

[0067] Cu: The Cu content is approximately 0.3% to 1.0%. Increasing the Cu content facilitates the use of recycled products, particularly twich. Copper is an element involved in hardening deposition and is advantageous for increasing yield strength after T4 tempering and paint baking. In T4 tempering, solid solution Cu promotes formability and increases work hardening. Cu reduces hot and cold rolling suitability by causing edge cracks that reduce the usable width of the rolled sheet, or even causing breakage during manufacturing. Furthermore, Cu content exceeding approximately 1% leads to over-hardening and reduced formability, particularly bendability. Although Cu is known to reduce corrosion resistance, surprisingly, corrosion resistance is acceptable despite the Cu content according to this invention.

[0068] A compromise between recycling and these properties is favorably reached when Cu ≥ 0.35%, preferably Cu ≥ 0.43%, preferably Cu ≥ 0.45%, more preferably Cu ≥ 0.48%, more preferably Cu ≥ 0.50%, and / or Cu ≤ 0.98%, preferably Cu ≤ 0.97%.

[0069] In one embodiment, the mass content of Cu is at least about 0.35%, and at most about 0.45%, or at most about 0.55%, or at most about 0.65%, or at most about 0.75%, or at most about 0.85%, or at most about 0.95%. In one embodiment, the mass content of Cu is at least about 0.45%, and at most about 0.55%, or at most about 0.65%, or at most about 0.75%, or at most about 0.85%, or at most about 0.95%. In one embodiment, the mass content of Cu is at least about 0.55%, and at most about 0.65%, or at most about 0.75%, or at most about 0.85%, or at most about 0.95%. In one embodiment, the mass content of Cu is at least about 0.65%, and at most about 0.75%, or at most about 0.85%, or at most about 0.95%. In one embodiment, the mass content of Cu is at least about 0.75%, and at most about 0.85%, or at most about 0.95%. In one embodiment, the mass content of Cu is at least about 0.85%, and at most about 0.95%.

[0070] Mn: The Mn content is approximately 0.2% to 0.6%. Increasing the Mn content facilitates the use of recycled products, especially twich. Manganese can contribute to common intermetallic precipitates and dispersed phases. Mn can reduce formability in T4 grades, particularly due to increased intermetallic compound fraction and reduced work hardening ability at high strains.

[0071] A compromise between recycling and these properties is favorably reached when Mn ≥ 0.20%, preferably Mn ≥ 0.21%, preferably Mn ≥ 0.22%, and / or Mn ≤ 0.55%, preferably Mn ≤ 0.52%, more preferably Mn ≤ 0.50%, more preferably Mn ≤ 0.47%, more preferably Mn ≤ 0.45%, more preferably Mn ≤ 0.43%, more preferably Mn ≤ 0.41%, more preferably Mn ≤ 0.39%, more preferably Mn ≤ 0.37%, more preferably Mn ≤ 0.35%, and more preferably Mn ≤ 0.33%.

[0072] In one embodiment, the mass content of Mn is at least about 0.20%, and at most about 0.30%, or at most about 0.40%, or at most about 0.50%, or at most about 0.60%. In one embodiment, the mass content of Mn is at least about 0.30%, and at most about 0.40%, or at most about 0.50%, or at most about 0.60%. In one embodiment, the mass content of Mn is at least about 0.40%, and at most about 0.50%, or at most about 0.60%. In one embodiment, the mass content of Mn is at least about 0.50%, and at most about 0.60%.

[0073] Mg: The Mg content is approximately 0.2% to 0.6%. Increasing the Mg content facilitates the use of recycled products, especially twich. Mg2Si precipitates contribute to the hardening of the alloy during aging, for example, during paint baking. Excess Si relative to Mg is advantageous for formability in T4 temper. The presence of Mg increases the yield strength in T4 temper, making formability more difficult.

[0074] A compromise between recycling and these properties is favorably reached when Mg ≥ 0.22%, preferably Mg ≥ 0.25%, more preferably Mg ≥ 0.27%, more preferably Mg ≥ 0.32%, more preferably Mg ≥ 0.35%, and / or Mg ≤ 0.55%, preferably Mg ≤ 0.52%, more preferably Mg ≤ 0.50%, more preferably Mg ≤ 0.47%, and more preferably Mg ≤ 0.45%.

[0075] In one embodiment, the mass content of Mg is at least about 0.20%, and at most about 0.30%, or at most about 0.40%, or at most about 0.50%, or at most about 0.60%. In one embodiment, the mass content of Mg is at least about 0.30%, and at most about 0.40%, or at most about 0.50%, or at most about 0.60%. In one embodiment, the mass content of Mg is at least about 0.40%, and at most about 0.50%, or at most about 0.60%. In one embodiment, the mass content of Mg is at least about 0.50%, and at most about 0.60%.

[0076] Zn: The content is approximately 0.2% to 0.6%. Increasing the Zn content facilitates the use of recycled products, especially twitch. Since Zn is an additive element in aluminum alloys, it is advantageous to accept Zn, especially for the purpose of recycling aluminum scrap and waste from end-of-life vehicles. Zn hardens the alloy in T4 temper and after aging, but reduces formability in T4 temper.

[0077] For a compromise between recycling and these properties, it is advantageous to have Zn ≥ 0.20%, preferably ≥ 0.22%, more preferably ≥ 0.24%, more preferably ≥ 0.26%, more preferably ≥ 0.28%, more preferably ≥ 0.30%, more preferably ≥ 0.32%, and / or Zn ≤ 0.56%, preferably ≤ 0.54%, more preferably ≤ 0.52%.

[0078] In one embodiment, the mass content of Zn is at least about 0.20%, and at most about 0.30%, or at most about 0.40%, or at most about 0.50%, or at most about 0.60%. In one embodiment, the mass content of Zn is at least about 0.30%, and at most about 0.40%, or at most about 0.50%, or at most about 0.60%. In one embodiment, the mass content of Zn is at least about 0.40%, and at most about 0.50%, or at most about 0.60%. In one embodiment, the mass content of Zn is at least about 0.50%, and at most about 0.60%.

[0079] Cr: The Cr content is up to 0.1% by weight. Increasing the Cr content facilitates the use of recycled products, particularly twich. In some cases, it can be added to refine the particles and stabilize the structure. Reducing the Cr content generally improves moldability, as measured by LDH. Surprisingly, the inventors have found that, in some cases, a maximum Cr content of 0.08%, advantageously 0.05%, and preferably 0.03% does not hinder the recycling of large quantities of scrap from the automotive industry, particularly twich.

[0080] The compromise between recycling and these properties is a Cr content of up to 0.08% and / or preferably 0.01% or more.

[0081] In one embodiment, the mass content of Cr is at least about 0.01%, and at most about 0.02%, or at most about 0.03%, or at most about 0.04%, or at most about 0.05%, or at most about 0.06%, or at most about 0.07%, or at most about 0.08%, or at most about 0.09%, or at most about 0.10%. In one embodiment, the mass content of Cr is at least about 0.02%, and at most about 0.03%, or at most about 0.04%, or at most about 0.05%, or at most about 0.06%, or at most about 0.07%, or at most about 0.08%, or at most about 0.09%, or at most about 0.10%. In one embodiment, the mass content of Cr is at least about 0.03%, and at most about 0.04%, or at most about 0.05%, or at most about 0.06%, or at most about 0.07%, or at most about 0.08%, or at most about 0.09%, or at most about 0.10%. In one embodiment, the mass content of Cr is at least about 0.04%, and at most about 0.05%, or at most about 0.06%, or at most about 0.07%, or at most about 0.08%, or at most about 0.09%, or at most about 0.10%.

[0082] In one embodiment, the mass content of Cr is at least about 0.05%, and at most about 0.06%, or at most about 0.07%, or at most about 0.08%, or at most about 0.09%, or at most about 0.10%. In one embodiment, the mass content of Cr is at least about 0.06%, and at most about 0.07%, or at most about 0.08%, or at most about 0.09%, or at most about 0.10%. In one embodiment, the mass content of Cr is at least about 0.07%, and at most about 0.08%, or at most about 0.09%, or at most about 0.10%. In one embodiment, the mass content of Cr is at least about 0.08%, and at most about 0.09%, or at most about 0.10%. In one embodiment, the mass content of Cr is at least about 0.09%, and at most about 0.10%.

[0083] Ti: A maximum content of about 0.1%, preferably 0.10%, is required to avoid the conditions under which a primary phase is formed during vertical casting, which adversely affects all of the claimed properties. Increasing the Ti content facilitates the use of recycled products, particularly twiches. In one embodiment, the minimum Ti content is about 0.01%.

[0084] In one embodiment, the mass content of Ti is at least about 0.01%, and at most about 0.02%, or at most about 0.03%, or at most about 0.04%, or at most about 0.05%, or at most about 0.06%, or at most about 0.07%, or at most about 0.08%, or at most about 0.09%, or at most about 0.10%. In one embodiment, the mass content of Ti is at least about 0.02%, and at most about 0.03%, or at most about 0.04%, or at most about 0.05%, or at most about 0.06%, or at most about 0.07%, or at most about 0.08%, or at most about 0.09%, or at most about 0.10%. In one embodiment, the mass content of Ti is at least about 0.03%, and at most about 0.04%, or at most about 0.05%, or at most about 0.06%, or at most about 0.07%, or at most about 0.08%, or at most about 0.09%, or at most about 0.10%.

[0085] In one embodiment, the mass content of Ti is at least about 0.04%, and at most about 0.05%, or at most about 0.06%, or at most about 0.07%, or at most about 0.08%, or at most about 0.09%, or at most about 0.10%. In one embodiment, the mass content of Ti is at least about 0.05%, and at most about 0.06%, or at most about 0.07%, or at most about 0.08%, or at most about 0.09%, or at most about 0.10%. In one embodiment, the mass content of Ti is at least about 0.06%, and at most about 0.07%, or at most about 0.08%, or at most about 0.09%, or at most about 0.10%. In one embodiment, the mass content of Ti is at least about 0.07%, and at most about 0.08%, or at most about 0.09%, or at most about 0.10%. In one embodiment, the mass content of Ti is at least about 0.08% and at most about 0.09% or at most about 0.10%.

[0086] Sn, Pb, Zr, V, Sr, Ni: The maximum content of each of these elements is about 0.1%, preferably 0.10%. Increasing the content of each of these elements facilitates the use of recycled products, particularly twitch. In one embodiment, the minimum content of each of these elements is about 0.01%. In one embodiment, the content of each of these elements is at least about 0.01%, or at least about 0.02%, or at least about 0.03%, or at least about 0.04%, or at least about 0.05%, or at least about 0.06%, or at least about 0.07%, or at least about 0.08%, and / or up to about 0.09%, or up to about 0.08%, or up to about 0.07%, or up to about 0.06%, or up to about 0.05%, or up to about 0.04%, or up to about 0.03%, or up to about 0.02%.

[0087] To our surprise, the inventors have found that, in some cases, a maximum Ni content of 0.08%, preferably 0.05%, and more preferably 0.03%, does not hinder the recycling of large quantities of scrap from the automotive industry, particularly twitch.

[0088] Other elements are typically impurities, and their content is kept below 0.05%, preferably strictly below 0.05%, totaling less than 0.15%, with the remainder being aluminum.

[0089] In one embodiment, the alloy according to the present invention comprises at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, or at least 90% post-consumer waste, or at least preferably waste from end-of-life vehicles, more preferably waste from aluminum shredded by an automobile shredder.

[0090] In a favorable embodiment, the composition of the alloy according to the present invention is as follows: Si: 1.7%~7.0% Fe: 0.2%~0.8% Cu: 0.3%~1.0%, Mn: 0.2%~0.35% Mg: 0.2%~0.6% Zn: 0.2%~0.6%, Ti, Sn, Pb, Zr, V, Sr: ≦0.1%, Cr ≤ 0.08%, Ni ≤ 0.08%, Other elements: ≤0.05% each, ≤0.15% total. Remainder: Al.

[0091] In another advantageous embodiment, the composition of the alloy according to the present invention is as follows: Si: 1.7%~7.0% Fe: 0.2%~0.8% Cu: 0.40%~1.0%, Mn: 0.2%~0.6% Mg: 0.2%~0.6% Zn: 0.2%~0.6%, Ti, Sn, Pb, Zr, V, Sr: ≦0.1%, Cr ≤ 0.08%, Ni ≤ 0.08%, Other elements: ≤0.05% each, ≤0.15% total. Remainder: Al.

[0092] In another advantageous embodiment, the composition of the alloy according to the present invention is as follows: Si: 2.8%~3.2%, preferably 2.8%~3.0% Fe: 0.30%~0.45%, preferably with a minimum value of 0.35% and / or preferably with a maximum value of 0.40%. Cu: 0.50%~0.65%, preferably with a minimum value of 0.55% and / or a maximum value of 0.60%. Mn: 0.2%~0.30%, preferably with a minimum value of 0.20% and / or preferably with a maximum value of 0.25%. Mg: 0.30%~0.45%, preferably with a minimum value of 0.35% and / or preferably with a maximum value of 0.40%. Zn: 0.25%~0.40%, preferably with a minimum value of 0.30% and / or preferably with a maximum value of 0.35%. Ti, Sn, Pb, Zr, V, Sr: ≤0.10%, preferably 0.08%.

[0093] The above embodiment strikes a compromise between lower hardness after paint curing, higher formability and bendability, less cracking during rolling, slightly more corrosion, and lower recyclability.

[0094] The embodiments described below offer a compromise between the properties of higher hardness, lower formability and bendability, better corrosion resistance, slightly higher rolling cracking, and better recyclability of the paint-baked finish.

[0095] In another advantageous embodiment, the composition of the alloy according to the present invention is as follows: Si: 3.7%~4.1%, preferably 3.9%~4.1% Fe: 0.35%~0.50%, preferably with a minimum value of 0.40% and / or preferably with a maximum value of 0.45%. Cu: 0.70% to 1%, preferably with a minimum value of 0.80% and / or preferably with a maximum value of 0.97%. Mn: 0.2%~0.30%, preferably with a minimum value of 0.20% and / or preferably with a maximum value of 0.25%. Mg: 0.30%~0.45%, preferably with a minimum value of 0.35% and / or preferably with a maximum value of 0.40%. Zn: 0.45%~0.60%, preferably with a minimum value of 0.50% and / or preferably with a maximum value of 0.55%. Ti, Sn, Pb, Zr, V, Sr: ≤0.10%, more preferably 0.08% Cr ≤ 0.08%, Ni ≤ 0.08%, Other elements: ≤0.05% each, ≤0.15% total. Remainder: Al.

[0096] In the embodiments described below, by reducing the Si and Zn content, the moldability and bendability are improved compared to the composition described immediately prior, thereby suppressing hardness while allowing a certain tolerance for Cu contamination, which often occurs in the form of electrical wiring.

[0097] In another advantageous embodiment, the composition of the alloy according to the present invention is as follows: Si: 3.0%~3.6%, preferably with a minimum value of 3.2% and / or preferably with a maximum value of 3.8%. Fe: 0.35%~0.50%, preferably with a minimum value of 0.40% and / or preferably with a maximum value of 0.45%. Cu: 0.70% to 1%, preferably with a minimum value of 0.80% and / or preferably with a maximum value of 0.97%. Mn: 0.2%~0.30%, preferably with a minimum value of 0.20% and / or preferably with a maximum value of 0.25%. Mg: 0.30%~0.45%, preferably with a minimum value of 0.35% and / or preferably with a maximum value of 0.40%. Zn: 0.35%~0.50%, preferably with a minimum value of 0.40% and / or preferably with a maximum value of 0.45%. Ti, Sn, Pb, Zr, V, Sr: ≤0.10%, more preferably 0.08% Cr ≤ 0.08%, Ni ≤ 0.08%, Other elements: ≤0.05% each, ≤0.15% total. Remainder: Al.

[0098] The present invention also relates to rolled alloy products according to the present invention.

[0099] In advantageous embodiments, the rolled products according to the present invention are solution-treated, quenched and pre-aged tempers, or solution-treated, quenched and aged tempers. These tempers allow the alloy to harden during paint curing. Pre-aging allows the alloy to be stabilized during natural aging or aging during storage before use of the alloy.

[0100] The product according to the present invention has advantageous rolling deformation suitability. Rolling suitability is judged to be good, in particular when little or no cracks or short cracks are formed during rolling, that is, when the tendency to crack is low, especially during cold rolling. By performing a cold rolling test as described in the examples, crackability is measured in millimeters according to the maximum length of cracks formed in the transverse direction of rolling after 6 passes of cold rolling from a hot-rolled thickness of 6 mm to a thickness of 1 mm. The rolled product according to the present invention has advantageous crackability of 5 mm or less, preferably 4 mm or less, and more preferably 3 mm or less.

[0101] In one embodiment, the rolled product according to the present invention has an LDH of 27.5 mm or more, preferably 28.0 mm or more, more preferably 28.5 mm or more, and more preferably 28.7 mm or more. Increasing the LDH value can improve the moldability for stamping.

[0102] In one embodiment, the rolled product according to the present invention has a minimum yield strength Rp0.2 in a T4 temper of 70 MPa, preferably 80 MPa, more preferably 90 MPa and / or a maximum yield strength Rp0.2 in a T4 temper of 140 MPa, preferably 130 MPa, more preferably 120 MPa. If the yield strength in a T4 temper is too low, the yield strength after paint curing is limited. If the yield strength in a T4 temper is too high, the stamping force increases. Limiting the maximum yield strength in a T4 temper is a compromise that allows for improved formability as measured by LDH. In one embodiment, the yield strength Rp0.2 in a T4 temper has a minimum value of 80 MPa and a maximum value of 100 MPa. This embodiment is a compromise that allows for improved hot and cold deformation suitability and formability without crack formation. In another embodiment, the yield strength Rp0.2 in a T4 temper has a minimum value of 105 MPa and a maximum value of 125 MPa. This embodiment represents a compromise that enables improved recyclability.

[0103] In one embodiment, the rolled product according to the present invention has a minimum yield strength Rp0.2 after paint curing at 200 MPa, preferably 210 MPa, and / or a maximum yield strength Rp0.2 after paint curing at 260 MPa, preferably 250 MPa. Increasing the yield strength after paint curing is advantageous for reducing the thickness of the part. In one embodiment, the minimum yield strength after paint curing is 225 MPa, preferably 235 MPa. This embodiment is a compromise that allows for further improvement of recyclability.

[0104] Remarkably, the composition according to the present invention makes it possible to obtain a work hardening coefficient comparable to that of a reference alloy while improving recyclability.

[0105] The method for manufacturing rolled products includes the following sequential steps: feeding, optionally sorting, alloy smelting, casting, homogenization and / or reheating, hot deformation and optionally cold deformation, solution treatment and quenching, optionally pre-aging, and natural aging.

[0106] Aluminum alloy and additive metals are supplied, and the aluminum alloy is in the form of post-consumer waste, with at least 20%, preferably at least 30%, preferably at least 40%, preferably at least 50%, preferably at least 60%, and preferably at least 70% being of the form of post-consumer waste.

[0107] Post-consumer waste is preferably at least 20%, preferably at least 30%, preferably at least 40%, preferably at least 50%, preferably at least 60%, and preferably at least 70% in the form of aluminum or twitch shredded by an automobile shredder.

[0108] Optionally, post-consumer waste is sorted. In a favorable embodiment, post-consumer waste is crushed and separated by sieving, waste larger than 1 cm is sorted by alloy family, and analysis is performed by LIBS (laser-induced breakdown spectroscopy) or XRT (X-ray transmission), if analysis is favorable.

[0109] The alloy according to the present invention is smelted from an aluminum alloy that optionally contains selected post-consumer waste and supplied additive metals.

[0110] A metal is cast using the alloy according to the present invention. Preferably, the casting is carried out by semi-continuous vertical casting (DC casting) with direct cooling. In the case of hot deformation by rolling, the metal is advantageously a rolled sheet, typically with a thickness of at least 250 mm.

[0111] The metal is typically homogenized and / or reheated at a temperature above the alloy's sorbus temperature, avoiding localized melting or combustion, for a minimum period of 2 hours, preferably 3 hours, more preferably 4 hours, and a maximum period of 7 hours, preferably 6 hours, more preferably 5 hours. The homogenization and / or reheating temperature is preferably a maximum of 560°C, preferably 550°C, more preferably 540°C, more preferably 530°C, and a minimum of 490°C, preferably 500°C. Temperatures that are too high or too low will degrade the mechanical properties of the product.

[0112] The metal is hot-deformed by rolling and, if desired, cold-deformed.

[0113] In one embodiment, the metal in the form of a rolled sheet is typically hot-rolled to a thickness of 3 to 8 mm. The starting temperature for hot rolling is typically 450°C to 550°C. Optionally, the rolled product obtained after hot rolling is cold-rolled to a thickness of typically 0.5 to 4 mm. In one embodiment, the thickness is 0.7 to 3 mm. In another embodiment, the thickness is 0.9 to 2 mm.

[0114] The metal processed in this way is then subjected to solution treatment and subsequently quenched.

[0115] Solution treatment is typically carried out at a solution treatment temperature above the alloy's sorbus temperature, while avoiding localized melting or combustion, and then quenched, preferably in a continuous furnace. Solution treatment that is too low in temperature and / or too short in duration degrades the mechanical properties of the sheet material due to insufficient solution treatment. Solution treatment that is too high in temperature causes combustion that degrades the mechanical properties. Solution treatment that is too long reduces productivity. Preferably, the solution treatment is carried out for 15 to 300 seconds. The solution treatment temperature is preferably a maximum of 560°C, preferably 550°C, more preferably 540°C, more preferably 530°C, and a minimum of 490°C, preferably 500°C.

[0116] Next, the solution-treated product is typically quenched with water, air, or a continuous combination of water and air at a rate exceeding 30°C / second, and optimally at least 100°C / second. Preferably, the product is quenched to a temperature of 60-100°C. Insufficient cooling rate will result in an incomplete solution treatment, leading to a decrease in the mechanical properties of the sheet material.

[0117] Optionally, the product is then reheated and pre-aging is carried out typically at a pre-aging temperature of 60°C to 120°C for 1 to 24 hours, preferably at 60°C to 100°C for 2 to 16 hours. In the case of rolled products, pre-aging can be obtained by cooling to room temperature for at least 40 hours after coiling. Pre-aging allows for improvement of the response to paint baking, which is the difference between the yield strength in T4 temper and the yield strength after paint baking.

[0118] The resulting product is then aged at room temperature, preferably for 24 hours to 6 months, and preferably for 72 hours to 5 months.

[0119] In one embodiment, the product obtained in this manner is subsequently subject to aging.

[0120] In another embodiment, the product obtained in this manner is painted and undergoes little to no heat treatment by paint baking.

[0121] The products according to the present invention are advantageously used for manufacturing automobile body parts. In one embodiment, the products according to the present invention are used as lining sheet materials, such as door linings and hood linings. For some automobile parts, particularly linings, the thickness is 0.7 to 2.0 mm. A thickness of less than 0.7 mm is too thin to ensure the rigidity of the components including the lining. A thickness greater than 2.0 mm would make the components including the lining too heavy for the user and the vehicle. In one embodiment, the products according to the present invention are used as structural components, such as top hat reinforcements. In one embodiment, the products according to the present invention are used as battery tray members, particularly as the bottom of the battery tray. The thickness of the bottom of the battery tray is typically 1.5 to 4.0 mm, preferably 2 to 3 mm. [Examples]

[0122] This disclosure is further illustrated by the following embodiments. These embodiments are intended solely to illustrate the present invention and are not intended to limit it.

[0123] Various alloys were tested in the laboratory according to the compositions in Table 1. These alloys were cast into 50 mm thick ingots by vertical semi-continuous casting (direct chill casting) after sculpting. Alloys J, K, and L are examples of 6XXX series alloys used for sheet metal in automotive industry applications. In Table 1, examples C and D according to the present invention are indicated as "E", and counterexamples as "CE". The compositions in Table 1 are in weight percent, with each of the other elements being ≤0.05%, the total being ≤0.15%, and the remainder being aluminum.

[0124] [Table 1]

[0125] The recyclability of these alloys was evaluated using representative twitch compositions according to Table 2.

[0126] [Table 2]

[0127] The recyclability of various alloys A through L was evaluated by calculating the maximum amount of the average composition for each element, as shown in Table 2 below. A value greater than 100% means that the twitch does not supply the amount of that element, and therefore there is nothing to restrict the introduction of the twitch to produce an alloy of that element. A value less than 100% means that the twitch supplies an excess of that element, and therefore the introduction of the twitch must be restricted to produce the alloy. Thus, to define its recyclability, it is only necessary to consider the minimum values ​​for all elements in each alloy being evaluated. Alloys J, K, and L are alloys with lower twitch recyclability.

[0128] [Table 3]

[0129] The ingots were reheated to 520°C, with the exception of reference products J and L, which were reheated to 560°C, and then hot-rolled while maintaining a temperature above 300°C.

[0130] Subsequently, the ingots were cold-rolled in six passes from a hot-rolled thickness of 5 mm to a thickness of 1 mm, with the exception of reference products J and L, which were cold-rolled from a hot-rolled thickness of 7 mm.

[0131] The cracking tendency during cold rolling was evaluated by measuring the length of cracks at the transverse edges, a condition known as "cracking ability." Crack lengths were measured at the edges after cold rolling to 1 mm, and the results are shown in Table 4.

[0132] [Table 4]

[0133] Samples were taken at a thickness of 3 mm. These samples were solution-treated at 510°C (560°C for reference products J and L) for 10 seconds, then quenched, and subsequently pre-aged at 80°C for 8 hours. These samples were then characterized by T4 tempering or after simulation of paint baking (BH) at 180°C for 20 minutes. The results are shown in Table 5.

[0134] Static tensile mechanical properties were measured in the transverse direction of the rolling process.

[0135] LDH was measured in the transverse direction of the rolling process.

[0136] The bending, or alpha, was characterized by a bending axis parallel to the direction of rolling.

[0137] Intergranular corrosion in acidic environments was measured according to ISO 11846 standards.

[0138] The results are shown in Table 5.

[0139] [Table 5]

[0140] Figures 1-3 show that Examples C and D of the present invention represent the best compromise between recyclability, deformability and formability (LDH) by crack evaluation in the T4 temper, and mechanical properties of yield strength and elongation.

[0141] The tensile work hardening coefficient n4-6 was characterized for 3 mm thick samples in the T4 temper. Examples C and D had good coefficients similar to reference products J, K, and L, and were better than the other examples.

Claims

1. In weight percentage, Si: about 1.7% to about 7.0%, Fe: approximately 0.2% to approximately 0.8% Cu: about 0.3% to about 1.0%, Mn: about 0.2% to about 0.6%, Mg: about 0.2% to about 0.6%, Zn: about 0.2% to about 0.6%, Ti, Cr, Sn, Pb, Zr, V, Sr, Ni: ≦about 0.1%, Other elements: ≤0.05% each, ≤0.15% total. Remainder: Al An aluminum alloy having the following composition.

2. In weight percentage, Si: 1.7% to 7.0%, Fe: 0.2% to 0.8%, Cu: 0.3% to 1.0%, Mn: 0.2% to 0.35%, Mg: 0.2% to 0.6%, Zn: 0.2% to 0.6%, Ti, Sn, Pb, Zr, V, Sr: ≦0.1%, Cr ≤ 0.08%, Ni ≤ 0.08%, Other elements: ≤0.05% each, ≤0.15% total. Remainder: Al The alloy according to claim 1, having the following composition.

3. The alloy according to claim 1 or 2, characterized in that Si ≥ 2.0%, preferably Si ≥ 2.2%, more preferably Si ≥ 2.5%, more preferably Si ≥ 2.8%, and / or Si ≤ 6%, preferably Si ≤ 5%, more preferably Si ≤ 4.3%, and more preferably Si ≤ 4.1%.

4. The alloy according to any one of claims 1 to 3, characterized in that Fe ≥ 0.25%, preferably Fe ≥ 0.30%, more preferably Fe ≥ 0.33%, more preferably Fe ≥ 0.35%, more preferably Fe ≥ 0.37%, and / or Fe ≤ 0.75%, preferably Fe ≤ 0.65%, more preferably Fe ≤ 0.55%, more preferably Fe ≤ 0.50%, and more preferably Fe ≤ 0.45%.

5. The alloy according to any one of claims 1 to 4, characterized in that Cu ≥ 0.43%, preferably Cu ≥ 0.45%, more preferably Cu ≥ 0.48%, more preferably Cu ≥ 0.50%, more preferably Cu ≥ 0.35% and / or Cu ≤ 0.98%, preferably Cu ≤ 0.97%, more preferably Cu ≤ 0.95%, more preferably Cu ≤ 0.92%, and more preferably Cu ≤ 0.90%.

6. The alloy according to any one of claims 1 to 5, characterized in that Mg ≥ 0.22%, preferably Mg ≥ 0.25%, more preferably Mg ≥ 0.27%, more preferably Mg ≥ 0.32%, more preferably Mg ≥ 0.35%, and / or Mg ≤ 0.55%, preferably Mg ≤ 0.52%, more preferably Mg ≤ 0.50%, more preferably Mg ≤ 0.47%, and more preferably Mg ≤ 0.45%.

7. The alloy according to any one of claims 1 to 6, characterized in that Mn ≥ 0.20%, preferably Mn ≥ 0.21%, preferably Mn ≥ 0.22%, more preferably Mn ≥ 0.23%, more preferably Mn ≥ 0.24%, more preferably Mn ≥ 0.25%, and / or Mn ≤ 0.55%, preferably Mn ≤ 0.52%, more preferably Mn ≤ 0.50%, more preferably Mn ≤ 0.47%, more preferably Mn ≤ 0.45%, more preferably Mn ≤ 0.43%, more preferably Mn ≤ 0.41%, more preferably Mn ≤ 0.39%, more preferably Mn ≤ 0.37%, more preferably Mn ≤ 0.35%, and more preferably Mn ≤ 0.33%.

8. Si: 2.8% to 3.2%, preferably 2.8% to 3.0% Fe: 0.30% to 0.45%, preferably with a minimum value of 0.35% and / or preferably with a maximum value of 0.40%. Cu: 0.50% to 0.65%, preferably with a minimum value of 0.55% and / or a maximum value of 0.60%. Mn: 0.2% to 0.30%, preferably with a minimum value of 0.20% and / or preferably with a maximum value of 0.25%. Mg: 0.30% to 0.45%, preferably with a minimum value of 0.35% and / or preferably with a maximum value of 0.40%. Zn: 0.25% to 0.40%, preferably with a minimum value of 0.30% and / or preferably with a maximum value of 0.35%. Ti, Sn, Pb, Zr, V, Sr: ≤0.10%, preferably 0.08% The alloy according to any one of claims 1 to 7, characterized in that it is the alloy described above.

9. Si: 3.7% to 4.1%, preferably 3.9% to 4.1% Fe: 0.35% to 0.50%, preferably with a minimum value of 0.40% and / or preferably with a maximum value of 0.45%. Cu: 0.70% to 1%, preferably with a minimum value of 0.80% and / or a maximum value of 0.97%. Mn: 0.2% to 0.30%, preferably with a minimum value of 0.20% and / or preferably with a maximum value of 0.25%. Mg: 0.30% to 0.45%, preferably with a minimum value of 0.35% and / or preferably with a maximum value of 0.40%. Zn: 0.45% to 0.60%, preferably with a minimum value of 0.50% and / or preferably with a maximum value of 0.55%. Ti, Sn, Pb, Zr, V, Sr: ≤0.10%, more preferably 0.08%, Cr ≤ 0.08%, Ni ≤ 0.08%, Other elements: ≤0.05% each, ≤0.15% total. Remainder: Al The alloy according to any one of claims 1 to 8, characterized in that it is the same as the one described above.

10. Si: 3.0% to 3.6%, preferably with a minimum value of 3.2% and / or preferably with a maximum value of 3.8%. Fe: 0.35% to 0.50%, preferably with a minimum value of 0.40% and / or preferably with a maximum value of 0.45%. Cu: 0.70% to 1%, preferably with a minimum value of 0.80% and / or preferably with a maximum value of 0.97%. Mn: 0.2% to 0.30%, preferably with a minimum value of 0.20% and / or preferably with a maximum value of 0.25%. Mg: 0.30% to 0.45%, preferably with a minimum value of 0.35% and / or preferably with a maximum value of 0.40%. Zn: 0.35% to 0.50%, preferably with a minimum value of 0.40% and / or preferably with a maximum value of 0.45%. Ti, Sn, Pb, Zr, V, Sr: ≤0.10%, more preferably 0.08%, Cr ≤ 0.08%, Ni ≤ 0.08%, Other elements: ≤0.05% each, ≤0.15% total. Remainder: Al The alloy according to any one of claims 1 to 9, characterized in that it is the alloy described above.

11. A rolled product of an alloy according to any one of claims 1 to 10.

12. A rolled product according to claim 11, which is tempered by solution treatment, quenching and pre-aging, or tempered by solution treatment, quenching and aging.

13. The rolled product according to claim 11 or 12, characterized in that the crack length is 5 mm or less, preferably 4 mm or less, more preferably 3 mm or less, and the crack length is the maximum length of the crack formed on the edge of the rolled product in the transverse direction of rolling after six passes of cold rolling from a hot-rolled thickness of 6 mm to a thickness of 1 mm.

14. The following sequence of steps: a) Supply of aluminum alloy and additive metals, wherein the aluminum alloy is in the form of at least 20% post-consumer waste, b) Optionally, sorting of post-consumer waste, c) Smelting of the alloy according to any one of claims 1 to 10 from an aluminum alloy containing selected post-consumer waste and supplied additive metals, optionally, d) Preferably by semi-continuous vertical casting, casting of the alloy into the base metal, e) Homogenization and / or reheating of the metal, f) Hot deformation and optionally cold deformation due to rolling of the metal, g) Solution treatment of the metal processed in this manner, followed by quenching, h) Optionally, pre-aging for 1 to 24 hours at a pre-aging temperature typically between 60 and 120°C. i) Preferably, natural aging period of 24 hours to 6 months. A method for manufacturing the product according to any one of claims 11 to 13, including the method described above.

15. Use of the product according to any one of claims 11 to 13 for manufacturing automotive parts.

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