JP7599438B2 - Aluminum alloy with silicon, magnesium, copper and zinc - Google Patents

Description

The 6xxx series aluminum alloys are aluminum alloys with silicon and magnesium that produce magnesium silicide ( _Mg2Si ) precipitates. The 6061 alloy has been used in a variety of applications for several decades. However, it has been unclear to improve one or more properties of the aluminum alloy without degrading other properties. In automotive applications, a sheet that has good formability before heat treatment but high strength after heat treatment would be useful.

In general, this patent application relates to a novel aluminum alloy and a method for producing the same, the novel aluminum alloy generally comprising 0.70-1.4 wt.% Si, 0.70-1.3 wt.% Mg, where (wt.% Mg)/(wt.% Si) is equal to or less than 1.40, 0.70-3.0 wt.% Zn, 0.55-1.3 wt.% Cu, where the sum of Si+Mg+Zn+Cu is equal to or less than 4.25 wt.%, 0.01-0.30 wt.% Fe, max. 0.70 wt.% Mn, max. 0.15 wt.% Cr, max. 0.20 wt.% Zr, max. 0.20 wt.% V, max. 0.25 wt.% Ti, the balance being aluminum, optional unavoidable elements and impurities. The new aluminum alloy may provide an improved combination of properties, such as improved combinations of two or more of strength after natural aging, paint bake strength, T6 strength, formability, ductility, and corrosion resistance. The new aluminum alloy may be used in a variety of applications, such as, for example, automotive applications (e.g., as a sheet product).

<i. Composition>
As indicated above, the new aluminum alloy generally comprises (and in some instances consists essentially of, or consists of) 0.70-1.4 wt.% Si, 0.70-1.3 wt.% Mg, where (wt.% Mg/(wt.% Si) is equal to or less than 1.40, 0.70-3.0 wt.% Zn, 0.55-1.3 wt.% Cu, where the total of Si+Mg+Zn+Cu is equal to or less than 4.25 wt.%, 0.01-0.30 wt.% Fe, up to 0.70 wt.% Mn, up to 0.15 wt.% Cr, up to 0.20 wt.% Zr, up to 0.20 wt.% V, and up to 0.25 wt.% Ti, with the balance being aluminum, optional unavoidable elements, and impurities. The use of these particular amounts of elements can result in uniquely useful products for use in, for example, automotive applications where good formability is required before heat treatment and high strength is also required after heat treatment.

As noted above, the new aluminum alloy generally includes 0.70-1.4 wt.% Si. Silicon can promote strength. As shown in the examples below, use of silicon beyond this range can be detrimental. In one embodiment, the new aluminum alloy includes at least 0.75 wt.% Si. In another embodiment, the new aluminum alloy includes at least 0.80 wt.% Si. In yet another embodiment, the new aluminum alloy includes at least 0.85 wt.% Si. In one embodiment, the new aluminum alloy includes no more than 1.35 wt.% Si. In another embodiment, the new aluminum alloy includes no more than 1.30 wt.% Si. In yet another embodiment, the new aluminum alloy includes no more than 1.25 wt.% Si. In another embodiment, the new aluminum alloy includes no more than 1.20 wt.% Si. In yet another embodiment, the new aluminum alloy includes no more than 1.15 wt.% Si. In another embodiment, the new aluminum alloy includes no more than 1.10 wt.% Si. In yet another embodiment, the new aluminum alloy includes no more than 1.05 wt.% Si.

As noted above, the new aluminum alloy generally includes 0.70-1.3 wt.% Mg. Magnesium can promote strength. As shown in the examples below, use of magnesium beyond this range can be detrimental. In one embodiment, the new aluminum alloy includes at least 0.75 wt.% Mg. In another embodiment, the new aluminum alloy includes at least 0.80 wt.% Mg. In one embodiment, the new aluminum alloy includes no more than 1.25 wt.% Mg. In another embodiment, the new aluminum alloy includes no more than 1.20 wt.% Mg. In yet another embodiment, the new aluminum alloy includes no more than 1.15 wt.% Mg. In another embodiment, the new aluminum alloy includes no more than 1.10 wt.% Mg. In yet another embodiment, the new aluminum alloy includes no more than 1.05 wt.% Mg.

As noted above, the weight ratio of Mg:Si is generally 1.4:1 or less. An appropriate Mg:Si ratio can promote corrosion resistance at applicable strength levels. As shown in the examples below, use of Mg:Si ratios above this range can be detrimental. In one embodiment, the weight ratio of Mg:Si is 1.3:1 or less. In another embodiment, the weight ratio of Mg:Si is 1.2:1 or less. In one embodiment, the weight ratio of Mg:Si is at least 0.7:1. In another embodiment, the weight ratio of Mg:Si is at least 0.8:1. In yet another embodiment, the weight ratio of Mg:Si is at least 0.9:1.

As noted above, the new aluminum alloy generally includes 0.70-3.0 wt.% Zn. Zinc can promote strength and proper natural aging response. As shown in the examples below, use of zinc beyond this range can be detrimental. In one embodiment, the new aluminum alloy includes at least 0.75 wt.% Zn. In another embodiment, the new aluminum alloy includes at least 0.85 wt.% Zn. In yet another embodiment, the new aluminum alloy includes at least 0.95 wt.% Zn. In another embodiment, the new aluminum alloy includes at least 1.0 wt.% Zn. In yet another embodiment, the new aluminum alloy includes at least 1.05 wt.% Zn. In one embodiment, the new aluminum alloy includes no more than 2.8 wt.% Zn. In another embodiment, the new aluminum alloy includes no more than 2.6 wt.% Zn. In yet another embodiment, the new aluminum alloy includes no more than 2.4 wt.% Zn. In another embodiment, the new aluminum alloy includes no more than 2.2 wt.% Zn. In yet another embodiment, the new aluminum alloy includes up to 2.0 wt.% Zn. In another embodiment, the new aluminum alloy includes up to 1.8 wt.% Zn.

As noted above, the new aluminum alloy generally includes 0.55-1.3 wt.% Cu. Copper can promote strength, corrosion resistance, and natural aging response. As shown in the examples below, use of copper beyond this range can be detrimental. In one embodiment, the new aluminum alloy includes at least 0.60 wt.% Cu. In another embodiment, the new aluminum alloy includes at least 0.65 wt.% Cu. In yet another embodiment, the new aluminum alloy includes at least 0.70 wt.% Cu. In one embodiment, the new aluminum alloy includes no more than 1.25 wt.% Cu. In another embodiment, the new aluminum alloy includes no more than 1.20 wt.% Cu. In yet another embodiment, the new aluminum alloy includes no more than 1.15 wt.% Cu. In another embodiment, the new aluminum alloy includes no more than 1.10 wt.% Cu. In yet another embodiment, the new aluminum alloy includes no more than 1.05 wt.% Cu.

As noted above, the solutes in the alloy are limited, with the total of Si+Mg+Zn+Cu not exceeding 4.25 wt.%. As shown in the examples below, the use of excess solutes can be detrimental, hence the stated limits.

As indicated above, the new aluminum alloy generally includes 0.01-0.30 wt.% Fe. Iron can promote proper grain structure and it can be cost-effective to use more than 0.10 wt.% Fe. Use of iron beyond this range may not be cost-effective and/or harmful. It is necessary to limit the amount of iron in the alloy so that large primary particles are avoided/restricted/limited during the manufacture of the aluminum alloy product. In one embodiment, the new aluminum alloy includes at least 0.05 wt.% Fe. In another embodiment, the new aluminum alloy includes at least 0.10 wt.% Fe. In yet another embodiment, the new aluminum alloy includes at least 0.12 wt.% Fe. In one embodiment, the new aluminum alloy includes no more than 0.25 wt.% Fe. In another embodiment, the new aluminum alloy includes no more than 0.22 wt.% Fe. In yet another embodiment, the new aluminum alloy includes no more than 0.19 wt.% Fe. In another embodiment, the new aluminum alloy includes up to 0.16 wt.% Fe.

As indicated above, the new aluminum alloy may contain up to 0.70 wt.% Mn. Manganese can promote proper grain structure. Use of manganese above this range can be detrimental. It is necessary to limit the amount of manganese in the alloy so that large primary particles are avoided/restricted/limited during the manufacture of aluminum alloy products. In one embodiment, the new aluminum alloy contains at least 0.05 wt.% Mn. In another embodiment, the new aluminum alloy contains at least 0.10 wt.% Mn. In yet another embodiment, the new aluminum alloy contains at least 0.15 wt.% Mn. In one embodiment, the new aluminum alloy contains no more than 0.60 wt.% Mn. In another embodiment, the new aluminum alloy contains no more than 0.50 wt.% Mn. In yet another embodiment, the new aluminum alloy contains no more than 0.45 wt.% Mn. In another embodiment, the new aluminum alloy contains no more than 0.40 wt.% Mn.

As indicated above, the new aluminum alloy includes 0.15 wt.% or less Cr. Use of more than 0.15 wt.% Cr can be detrimental to the grain structure and can cause problems with recyclability of the alloy. In one embodiment, the new aluminum alloy includes 0.12 wt.% Cr or less. In another embodiment, the new aluminum alloy includes 0.10 wt.% Cr or less. In yet another embodiment, the new aluminum alloy includes 0.08 wt.% Cr or less. In another embodiment, the new aluminum alloy includes 0.06 wt.% Cr or less. In yet another embodiment, the new aluminum alloy includes 0.04 wt.% Cr or less. In another embodiment, the new aluminum alloy includes 0.03 wt.% Cr or less. In yet another embodiment, the new aluminum alloy includes 0.02 wt.% Cr or less. In another embodiment, the new aluminum alloy includes 0.01 wt.% Cr or less.

As indicated above, the new aluminum alloy includes 0.20 wt.% Zr or less. Zirconium is less desirable than manganese for grain structure control, but can still be useful. It is necessary to limit the amount of zirconium in the alloy so that large primary particles during the manufacture of the aluminum alloy product are avoided/restricted/limited. In one embodiment, the new aluminum alloy includes 0.15 wt.% Zr or less. In another embodiment, the new aluminum alloy includes 0.10 wt.% Zr or less. In yet another embodiment, the new aluminum alloy includes 0.08 wt.% Zr or less. In another embodiment, the new aluminum alloy includes 0.03 wt.% Zr or less. In yet another embodiment, the new aluminum alloy includes 0.01 wt.% Zr or less. In one embodiment, the new aluminum alloy includes at least 0.01 wt.% Zr (e.g., when Zr is added/used in the alloy for grain structure control). In another embodiment, the new aluminum alloy includes at least 0.05 wt.% Zr. In one embodiment, the new aluminum alloy contains 0.07 to 0.15 wt.% Zr.

As indicated above, the new aluminum alloy includes 0.20 wt.% V or less. Vanadium is less desirable than manganese for grain structure control, but can still be useful. It is necessary to limit the amount of vanadium in the alloy so that large primary particles are avoided/restricted/limited during the manufacture of the aluminum alloy product. In one embodiment, the new aluminum alloy includes 0.15 wt.% V or less. In another embodiment, the new aluminum alloy includes 0.10 wt.% V or less. In yet another embodiment, the new aluminum alloy includes 0.08 wt.% V or less. In another embodiment, the new aluminum alloy includes 0.03 wt.% V or less. In yet another embodiment, the new aluminum alloy includes 0.01 wt.% V or less. In one embodiment, the new aluminum alloy includes at least 0.01 wt.% V (e.g., when V is added/used in the alloy for grain structure control). In another embodiment, the new aluminum alloy includes at least 0.05 wt.% V. In one embodiment, the new aluminum alloy includes 0.07-0.15 wt.% V.

As indicated above, the new aluminum alloy includes 0.25 wt.% or less Ti. Titanium may be used during casting for grain refinement. Higher concentrations of titanium may also promote corrosion resistance. It is necessary to limit the amount of titanium in the alloy so that large primary particles during the production of the alloy product are avoided/restricted/limited. In one embodiment, the new aluminum alloy includes at least 0.005 wt.% Ti. In another embodiment, the new aluminum alloy includes at least 0.01 wt.% Ti. In yet another embodiment, the new aluminum alloy includes at least 0.02 wt.% Ti. In yet another embodiment, the new aluminum alloy includes at least 0.05 wt.% Ti. In one embodiment, the new new aluminum alloy includes 0.20 wt.% Ti or less. In another embodiment, the new new aluminum alloy includes 0.15 wt.% Ti or less. In another embodiment, the new aluminum alloy includes 0.12 wt.% Ti or less. In yet another embodiment, the new new aluminum alloy includes 0.10 wt.% Ti or less. In another embodiment, the new new aluminum alloy includes up to 0.08 wt.% Ti. In yet another embodiment, the new new aluminum alloy includes up to 0.05 wt.% Ti. In another embodiment, the new new aluminum alloy includes up to 0.03 wt.% Ti. In one embodiment, the new new aluminum alloy includes 0.005-0.10 wt.% Ti. In another embodiment, the new aluminum alloy includes 0.01-0.05 wt.% Ti. In yet another embodiment, the new aluminum alloy includes 0.01-0.03 wt.% Ti. The titanium may be in elemental or compound form (e.g., _TiB2 or TiC).

As indicated above, the balance of the aluminum alloy is generally aluminum, optional unavoidable elements, and impurities. As used herein, "unavoidable elements" refers to elements or materials, other than those listed above, that may be optionally added to the alloy to aid in the production of the alloy. Examples of unavoidable elements include casting aids such as grain refiners and deoxidizers. Optional unavoidable elements may be included in the alloy in a cumulative amount of up to 1.0 wt.%. As one non-limiting example, one or more unavoidable elements may be added to the alloy during casting to reduce or limit (and in some cases eliminate) cracking of the ingot due to, for example, oxide folds, pits, and oxide patches. These types of unavoidable elements are generally referred to herein as deoxidizers. Some examples of deoxidizers include Ca, Sr, and Be. Calcium (Ca), when included in the alloy, is generally present in an amount up to about 0.05 wt.%, or up to about 0.03 wt.%. In some embodiments, Ca is included in the alloy in an amount of 0.001-0.03 wt.%, or about 0.05 wt.%, such as about 0.001-0.008 wt.% (or 10-80 ppm). Strontium (Sr) can be included in the alloy (in whole or in part) as a substitute for Ca, i.e., in the same or similar amount as Ca. Traditionally, the addition of beryllium (Be) has helped to reduce the tendency of ingots to crack, but for environmental, health, and safety reasons, some embodiments of the alloy are substantially free of Be. When Be is included in the alloy, it is generally present in an amount up to about 20 ppm. The unavoidable elements may be present in minor or significant amounts, and may themselves add desirable or other properties without departing from the alloys described herein, so long as the alloy retains the desirable properties described herein. However, it should be understood that the scope of the present disclosure should not/cannot be circumvented by the mere addition of an element in an amount that would not otherwise affect the desired obtained property combination herein.

The new aluminum alloy may contain small amounts of impurities. In one embodiment, the new aluminum alloy contains no more than 0.15 wt. % total impurities, and wherein the new aluminum alloy contains no more than 0.05 wt. % of each impurity. In another embodiment, the new aluminum alloy contains no more than 0.10 wt. % total impurities, and wherein the new aluminum alloy contains no more than 0.03 wt. % of each impurity.

<ii. Processing>
The new aluminum alloy may be useful in a variety of product forms, including, for example, ingots or ingot pieces, wrought product forms (plate, forgings, and extrusions), molded castings, additively manufactured products, and powder metallurgy products. For example, the new aluminum alloy may be processed into a variety of wrought forms, such as, for example, rolled forms (sheet, plate), extrusions, or forgings, in a variety of tempers. In this regard, the new aluminum alloy may be cast (e.g., direct chill casting or continuous casting) and then worked (hot and/or cold worked) into the appropriate product form (sheet, plate, extrusion, or forging). After working, the new aluminum alloy may be processed into one of the T, W, or F tempers in accordance with ANSI H35.1 (2009). In one embodiment, the new aluminum alloy is processed (heat treated) into "T" temper. In this regard, the new aluminum alloy may be processed to any of the tempers T1, T2, T3, T4, T5, T6, T7, T8, T9, or T10, in accordance with ANSI H35.1 (2009). In one embodiment, the product is processed to the T43 temper (e.g., according to the examples below). In another embodiment, the product is processed to the T6 temper (e.g., according to the examples below). In another embodiment, the new aluminum alloy is processed to a "W" temper (solution heat treated). In another embodiment, the solution heat treatment is not applied after processing the aluminum alloy into the appropriate product form, and therefore the new aluminum alloy may be processed to an "F" temper (as if secondarily processed).

In one embodiment, the novel aluminum alloy is a sheet product. In one embodiment, the sheet product has a thickness of 1.0 to 4.0 mm. In one embodiment, the sheet product is processed to a T4 temper. In one embodiment, the sheet product is processed to a T43 temper. In one embodiment, the sheet product is processed to a T43 temper and then paint baked (e.g., by heating at 180° C. for 20 minutes). In one embodiment, the sheet product is processed to a T43 temper and then paint baked and then artificially aged to a T6 temper (e.g., by heating at 180° C. for 8 hours). Such sheet products may be useful in automotive applications, as described in more detail below.

<iii. Properties>
As indicated above, the new aluminum alloy may provide an improved combination of properties. In one embodiment, the new aluminum alloy is a sheet product having a thickness of 1.0 to 4.0 mm, and the aluminum alloy sheet product provides at least one of the following properties:
(i) TYS-LT of 155 MPa or less after natural aging for seven days ("TYS-7NA");
(ii) TYS-LT of 175 MPa or less after natural aging for 90 days ("TYS-90NA");
(iii) (TYS-90NA) minus (TYS-7NA) is 20 MPa or less;
(iv) After natural aging for 30 days, when paint baking treatment is performed at 180°C for 20 minutes, TYS-LT has a strength of at least 235 MPa;
(v) After natural aging for 90 days, when paint baking treatment is performed at 180°C for 20 minutes, TYS-LT has a strength of at least 230 MPa;
(vi) TYS-LT of at least 350 MPa when naturally aged for 30 days followed by artificial aging at 180° C. for 8 hours.
In one embodiment, the aluminium alloy sheet product achieves at least two of the properties (i)-(vi) above. In another embodiment, the aluminium alloy sheet product achieves at least three of the properties (i)-(vi) above. In yet another embodiment, the aluminium alloy sheet product achieves at least four of the properties (i)-(vi) above. In another embodiment, the aluminium alloy sheet product achieves at least five of the properties (i)-(vi) above. In yet another embodiment, the aluminium alloy sheet product achieves all of the properties (i)-(vi) above.

As used herein, "TYS-LT" means the transverse tensile yield strength (0.2% offset) of the product measured in accordance with ASTM E8 and B557.

As used herein, "TYS-7NA" refers to the transverse tensile yield strength of the product after natural aging for seven days.

As used herein, "TYS-90NA" refers to the transverse tensile yield strength of the product after natural aging for 90 days.

As used herein, "paint baking" refers to the application of heat to a product to cure the paint or other polymers thereon. A typical automotive paint bake involves heating to 180°C, then holding at 180°C for 20 minutes (e.g., in an oven), followed by air cooling to ambient temperature.

As shown above, the new aluminum alloy sheet product can achieve a TYS-LT of 155 MPa or less after seven days of natural aging (i.e., TYS-7NA≦155 MPa). Low strength after natural aging is important to enable subsequent forming of the material (e.g., into automotive seat components). In one embodiment, the new aluminum alloy sheet product can achieve a TYS-LT of 150 MPa or less after seven days of natural aging (i.e., TYS-7NA≦150 MPa). In another embodiment, the new aluminum alloy sheet product can achieve a TYS-LT of 145 MPa or less after seven days of natural aging (i.e., TYS-7NA≦145 MPa).

As shown above, the new aluminum alloy sheet products can achieve TYS-LT of 175 MPa or less after 90 days of natural aging (i.e., TYS-90NA≦175 MPa). Low strength after natural aging is important to enable subsequent forming of the material (e.g., into automotive seat components). Furthermore, automotive seat products may be in inventory for several months, so the natural aging response/strength needs to be/remain low over long periods of time. In one embodiment, the new aluminum alloy sheet products can achieve TYS-LT of 170 MPa or less after 90 days of natural aging (i.e., TYS-90NA≦170 MPa). In another embodiment, the new aluminum alloy sheet products can achieve TYS-LT of 165 MPa or less after 90 days of natural aging (i.e., TYS-90NA≦165 MPa). In yet another embodiment, the new aluminum alloy sheet product may achieve a TYS-LT of 160 MPa or less after 90 days of natural aging (i.e., TYS-90NA≦160 MPa). In another embodiment, the new aluminum alloy sheet product may achieve a TYS-LT of 155 MPa or less after 90 days of natural aging (i.e., TYS-90NA≦155 MPa).

As indicated above, the natural aging response should be low. In one embodiment, the new aluminum alloy sheet product may achieve (TYS-90NA) minus (TYS-7NA) of 20 MPa or less. That is, the strength of the sheet product increases by 20 MPa or less from 7 days of natural aging to 90 days of natural aging. In another embodiment, the new aluminum alloy sheet product may achieve (TYS-90NA) minus (TYS-7NA) of 18 MPa or less. In yet another embodiment, the new aluminum alloy sheet product may achieve (TYS-90NA) minus (TYS-7NA) of 15 MPa or less. In another embodiment, the new aluminum alloy sheet product may achieve (TYS-90NA) minus (TYS-7NA) of 12 MPa or less. In yet another embodiment, the new aluminum alloy sheet product may achieve (TYS-90NA) minus (TYS-7NA) of 10 MPa or less. In another embodiment, the new aluminum alloy sheet product may achieve a modulus of 8 MPa or less when (TYS-90NA) minus (TYS-7NA).

As shown above, the new aluminum alloy sheet product can achieve a TYS-LT of at least 235 MPa after natural aging for 30 days and then paint baking for 20 minutes at 180°C. (The phrase "after natural aging for 30 days and then paint baking for 20 minutes at 180°C" is abbreviated herein to "30 day NA+ paint bake.") Because the paint bake generally occurs after natural aging and after the product is formed, high strength after the paint bake can be important. In one embodiment, the new aluminum alloy sheet product can achieve a TYS-LT of at least 240 MPa after 30 day NA+ paint bake. In another embodiment, the new aluminum alloy sheet product can achieve a TYS-LT of at least 245 MPa after 30 day NA+ paint bake. In yet another embodiment, the new aluminum alloy sheet product can achieve a TYS-LT of at least 250 MPa after 30 day NA+ paint bake. In another embodiment, the new aluminum alloy sheet product may achieve a TYS-LT of at least 255 MPa with a 30 day NA+ paint bake. In yet another embodiment, the new aluminum alloy sheet product may achieve a TYS-LT of at least 260 MPa with a 30 day NA+ paint bake. In another embodiment, the new aluminum alloy sheet product may achieve a TYS-LT of at least 265 MPa with a 30 day NA+ paint bake. In yet another embodiment, the new aluminum alloy sheet product may achieve a TYS-LT of at least 270 MPa with a 30 day NA+ paint bake.

As shown above, the new aluminum alloy sheet product can achieve a TYS-LT of at least 230 MPa when naturally aged for 90 days and then paint baked at 180°C for 20 minutes. (Herein, the phrase "when naturally aged for 90 days and then paint baked at 180°C for 20 minutes" is abbreviated to "90 day NA+ paint bake.") This can be important for low strength degradation after paint bake (e.g., to ensure that the product retains high strength). In one embodiment, the new aluminum alloy sheet product can achieve a TYS-LT of at least 235 MPa when naturally aged for 90 days and then paint baked at 180°C for 20 minutes. In yet another embodiment, the new aluminum alloy sheet product can achieve a TYS-LT of at least 240 MPa when naturally aged for 90 days and then paint baked at 180°C for 20 minutes. In yet another embodiment, the new aluminum alloy sheet product can achieve a TYS-LT of at least 245 MPa when naturally aged for 90 days and then paint baked at 180°C for 20 minutes. In another embodiment, the new aluminum alloy sheet product may achieve a TYS-LT of at least 250 MPa at 90 days NA+ paint bake.

As shown above, the new aluminum alloy sheet product can achieve a TYS-LT of at least 350 MPa when naturally aged for 30 days and then artificially aged at 180°C for 8 hours. (The phrase "when naturally aged for 30 days and then artificially aged at 180°C for 8 hours" is abbreviated herein as "30 days NA+AA.") In some embodiments, it can be useful to artificially age a product (e.g., a product that has been naturally aged and/or a product that has been paint baked) to increase its strength, and it can be important to achieve high strength. In one embodiment, the new aluminum alloy sheet product can achieve a TYS-LT of at least 355 MPa when naturally aged for 30 days and then artificially aged at 180°C for 8 hours. In another embodiment, the new aluminum alloy sheet product can achieve a TYS-LT of at least 360 MPa when naturally aged for 30 days and then artificially aged at 180°C for 8 hours. In yet another embodiment, the new aluminum alloy sheet product may achieve a TYS-LT of at least 365 MPa at 30 days NA+AA. In another embodiment, the new aluminum alloy sheet product may achieve a TYS-LT of at least 370 MPa at 30 days NA+AA.

The T6 temper by artificial aging can be heating for any suitable period and at any suitable temperature. In one embodiment, the T6 temper is heating at 180°C for 8 hours or substantially similar aging conditions as shown above. As will be appreciated by those skilled in the art, the aging temperature and/or time can be adjusted based on known aging principles and/or formulas. Thus, one skilled in the art can increase the aging temperature while decreasing the aging time, or vice versa, or slightly modify only one of these parameters and still achieve the same results as "aging at 180°C for 8 hours". Since there are many artificial aging techniques that would achieve the same results as "aging at 180°C for 8 hours", not all such alternative aging techniques are listed herein. The use of the phrase "or substantially equivalent artificial aging temperature and duration" or the phrase "or substantially equivalent technique" is used to capture all such alternative aging techniques. As can be appreciated, these alternative artificial aging steps can occur in one or more steps and at one or more temperatures.

The new aluminum alloy sheet may also achieve other important properties such as ductility and corrosion resistance. In one embodiment, the new aluminum alloy sheet product may achieve at least 15% elongation (4D) in the T43 temper when tested according to ASTM E8 and B557. In another embodiment, the new aluminum alloy sheet product achieves at least 18% elongation in the T43 temper. In yet another embodiment, the new aluminum alloy sheet product achieves at least 20% elongation in the T43 temper. In another embodiment, the new aluminum alloy sheet product achieves at least 22% elongation in the T43 temper. In another embodiment, the new aluminum alloy sheet product achieves at least 24% elongation in the T43 temper. In yet another embodiment, the new aluminum alloy sheet product achieves at least 26% elongation in the T43 temper. In another embodiment, the new aluminum alloy sheet product achieves at least 28% elongation in the T43 temper.

In one embodiment, the new aluminum alloy sheet product may achieve at least 10% elongation (4D) in the paint bake condition (e.g., T43+paint bake) when tested according to ASTM E8 and B557. In another embodiment, the new aluminum alloy sheet product achieves at least 12% elongation in the paint bake condition. In yet another embodiment, the new aluminum alloy sheet product achieves at least 14% elongation in the paint bake condition. In another embodiment, the new aluminum alloy sheet product achieves at least 16% elongation in the paint bake condition. In yet another embodiment, the new aluminum alloy sheet product achieves at least 18% elongation in the paint bake condition. In another embodiment, the new aluminum alloy sheet product achieves at least 20% elongation in the paint bake condition.

In one embodiment, the new aluminum alloy sheet product may achieve an elongation (4D) of at least 10% in the T6 temper when tested according to ASTM E8 and B557. In another embodiment, the new aluminum alloy sheet product achieves an elongation of at least 11% in the T6 temper. In yet another embodiment, the new aluminum alloy sheet product achieves an elongation of at least 12% in the T6 temper. In another embodiment, the new aluminum alloy sheet product achieves an elongation of at least 13% in the T6 temper. In yet another embodiment, the new aluminum alloy sheet product achieves an elongation of at least 14% in the T6 temper. In another embodiment, the new aluminum alloy sheet product achieves an elongation of at least 15% in the T6 temper.

In one embodiment, the novel aluminum alloy sheet product is corrosion resistant. In one embodiment, the corrosion resistance is at least intergranular corrosion resistance. In another embodiment, the corrosion resistance is at least filiform corrosion resistance. In another embodiment, the corrosion resistance is both intergranular and filiform corrosion resistance. Intergranular corrosion resistance shall be measured according to ASTM G110 (five specimens). Filiform corrosion resistance shall be measured according to ASTM G85-2, determining the resistance of the longest filiform corrosion perpendicular to each of three separate scribes after the sample is exposed for three weeks.

In relation to intergranular corrosion resistance, in one embodiment, the new aluminum alloy sheet product achieves a maximum corrosion depth of 225 micrometers or less and an average corrosion depth of 150 micrometers or less.

In relation to filiform corrosion resistance, in one embodiment, the new aluminum alloy sheet product achieves a maximum track length of 0.35 inches or less, but tests at least 8 tracks. In another embodiment, the new aluminum alloy sheet product achieves a maximum track length of 0.30 inches or less, but tests at least 8 tracks.

Due to the unique composition disclosed herein and appropriate processing, the new aluminum alloy products can be crack-free after formation (e.g., when pressed/formed into automotive components such as automotive panels). In one embodiment, the new aluminum alloy products are crack-free after formation (e.g., when pressed/formed into automotive panels/components), strong (after paint bake and/or T6 temper and as defined above), and corrosion resistant.

<iv. Product Use>
The new aluminum alloys described herein may be used in a variety of applications, such as automotive, rail, aerospace, or consumer electronics applications. For example, the new aluminum alloys may be formed into automotive parts. Non-limiting examples of automotive parts include car bodies and automotive panels. Non-limiting examples of automotive panels may include exterior panels, interior panels, for use in automotive doors, automotive hoods, or automotive trunks (decklids), among others. An example of an automotive body product may be a structural component, which may be used in welding together sheet metal components of a vehicle body (e.g., body-in-white). The new aluminum alloys may also be used in other transportation applications, such as light trucks or heavy trucks. Consumer electronics applications include laptop cases, battery cases, among other stamped and formed products.

v. Representative, Non-Limiting Terms
Below are some non-limiting representative clauses that define one or more inventions. These clauses are non-limiting examples and are not intended to, and do not, limit the inventions disclosed herein to the items set forth therein. Indeed, any of the subject matter described herein may be used to define one or more inventions.

Item 1. An aluminum alloy sheet product,
0.70 to 1.4 wt.% Si;
0.70 to 1.3 wt. % Mg;
wherein (wt %) of Mg/(wt %) of Si is 1.4:1 or less;
0.70 to 3.0 wt. % Zn;
0.55 to 1.3 wt.% Cu;
wherein the total amount of Si+Mg+Zn+Cu is 4.25% by weight or less;
0.01 to 0.30 wt. % Fe;
Mn up to 0.70 wt.%;
% Cr max.
% Zr;
Maximum 0.20 wt.% V;
and max 0.25 wt.% Ti,
The balance is aluminum, optional unavoidable elements and impurities.
the aluminum alloy sheet product has a thickness of 1.0 to 4.0 mm;
The aluminum sheet product has the following properties:
(i) TYS-LT of 155 MPa or less after natural aging for 7 days ("TYS-7NA");
(ii) TYS-LT of 175 MPa or less after natural aging for 90 days ("TYS-90NA");
(iii) (TYS-90NA) minus (TYS-7NA) is 20 MPa or less;
(iv) When naturally aged for 30 days and then painted and baked at 180° C. for 20 minutes, TYS-LT has a strength of at least 235 MPa;
(v) When naturally aged for 90 days and then painted and baked at 180° C. for 20 minutes, TYS-LT has a strength of at least 230 MPa;
(vi) when naturally aged for 30 days, followed by artificial aging at 180° C. for 8 hours, the aluminum alloy sheet product achieves at least one of the following: TYS-LT of at least 350 MPa.

Item 2. The aluminum alloy sheet product according to item 1, wherein the aluminum alloy contains at least 0.75% by weight Si, or at least 0.80% by weight Si, or at least 0.85% by weight Si.

Item 3. An aluminum alloy sheet product according to items 1 to 2, wherein the aluminum alloy contains 1.35% by weight or less of Si, or 1.30% by weight or less of Si, or 1.25% by weight or less of Si, or 1.20% by weight or less of Si, or 1.15% by weight or less of Si, or 1.10% by weight or less of Si, or 1.05% by weight or less of Si.

Item 4. An aluminum alloy sheet product according to any one of items 1 to 3, wherein the aluminum alloy contains at least 0.75 wt.% Mg or at least 0.80 wt.% Mg.

Item 5. An aluminum alloy sheet product according to any one of items 1 to 4, wherein the aluminum alloy contains 1.25% by weight or less of Mg, or 1.20% by weight or less of Mg, or 1.15% by weight or less of Mg, or 1.10% by weight or less of Mg, or 1.05% by weight or less of Mg.

Item 6. An aluminum alloy sheet product according to any one of items 1 to 5, in which (wt %) of Mg/(wt %) of Si is 1.3:1 or less, or 1.2:1 or less.

Item 7. An aluminum alloy sheet product according to any one of items 1 to 6, in which (wt %) Mg/(wt %) Si is at least 0.7:1, or at least 0.8:1, or at least 0.9:1.

Item 8. An aluminum alloy sheet product according to any one of items 1 to 7, wherein the aluminum alloy contains at least 0.75% by weight Zn, or at least 0.85% by weight Zn, or at least 0.95% by weight Zn, or at least 1.0% by weight Zn, or at least 1.05% by weight Zn.

Item 9. An aluminum alloy sheet product according to any one of items 1 to 8, wherein the aluminum alloy contains 2.8% by weight or less of Zn, or 2.6% by weight or less of Zn, or 2.4% by weight or less of Zn, or 2.2% by weight or less of Zn, or 2.0% by weight or less of Zn, or 1.8% by weight or less of Zn.

Item 10. An aluminum alloy sheet product according to any one of items 1 to 9, wherein the aluminum alloy contains at least 0.60 wt.% Cu, or at least 0.65 wt.% Cu, or at least 0.70 wt.% Cu.

Item 11. An aluminum alloy sheet product according to any one of items 1 to 10, wherein the aluminum alloy contains 1.25% by weight or less of Cu, or 1.20% by weight or less of Cu, or 1.15% by weight or less of Cu, or 1.10% by weight or less of Cu, or 1.05% by weight or less of Cu.

Item 12. An aluminum alloy sheet product according to any one of items 1 to 11, wherein the aluminum alloy contains at least 0.05 wt.% Fe, or at least 0.10 wt.% Fe, or at least 0.12 wt.% Fe.

Item 13. An aluminum alloy sheet product according to any one of items 1 to 12, wherein the aluminum alloy contains 0.25% by weight or less of Fe, or 0.22% by weight or less of Fe, or 0.19% by weight or less of Fe, or 0.16% by weight or less of Fe.

Item 14. An aluminum alloy sheet product according to any one of items 1 to 13, wherein the aluminum alloy contains at least 0.05 wt.% Mn, or at least 0.10 wt.% Mn, or at least 0.15 wt.% Mn.

Item 15. An aluminum alloy sheet product according to any one of items 1 to 14, wherein the aluminum alloy contains 0.60 wt% or less Mn, or 0.50 wt% or less Mn, or 0.45 wt% or less Mn, or 0.40 wt% or less Mn.

Item 16. An aluminum alloy sheet product according to any one of items 1 to 15, wherein the aluminum alloy contains 0.12 wt% or less of Cr, or 0.10 wt% or less of Cr, or 0.08 wt% or less of Cr, or 0.06 wt% or less of Cr, or 0.04 wt% or less of Cr, or 0.03 wt% or less of Cr, or 0.02 wt% or less of Cr, or 0.01 wt% or less of Cr.

Item 17. An aluminum alloy sheet product according to any one of items 1 to 16, wherein the aluminum alloy contains 0.15 wt.% or less Zr, or 0.10 wt.% or less Zr, or 0.08 wt.% or less Zr, or 0.05 wt.% or less Zr, or 0.03 wt.% or less Zr.

Item 18. An aluminum alloy sheet product according to any one of items 1 to 17, wherein the aluminum alloy contains at least 0.01 wt.% Zr.

Item 19. An aluminum alloy sheet product according to any one of items 1 to 18, wherein the aluminum alloy contains 0.15 wt.% or less of V, or 0.10 wt.% or less of V, or 0.08 wt.% or less of V, or 0.05 wt.% or less of V, or 0.03 wt.% or less of V.

Item 20. An aluminum alloy sheet product according to any one of items 1 to 19, wherein the aluminum alloy contains at least 0.01 wt. % V.

Item 21. An aluminum alloy sheet product according to any one of items 1 to 20, wherein the aluminum alloy contains 0.12 wt.% or less of Ti, or 0.10 wt.% or less of Ti.

Item 22. An aluminum alloy sheet product according to any one of items 1 to 21, wherein the aluminum alloy contains at least 0.01 wt.% Ti, or at least 0.02 wt.% Ti, or at least 0.05 wt.% Ti.

Item 23. An automotive seat product made from the aluminum alloy sheet product according to any one of items 1 to 22.

Item 24. An automobile seat product according to item 23, which realizes at least two of the properties (i) to (vi).

Item 25. An automobile seat product according to item 23, which realizes at least three of the properties (i) to (vi).

Item 26. An automobile seat product according to item 23, which realizes at least four of the properties (i) to (vi).

Item 27. An automobile seat product according to item 23, which realizes at least five of the properties (i) to (vi).

Item 28. An automobile seat product according to item 23, which realizes all of the properties (i) to (vi).

Item 29. An automotive seat product according to any one of items 23 to 28, in which the sheet product achieves property (i), and property (i) is 155 MPa or less, or 150 MPa or less, or 145 MPa or less.

Item 30. An automotive seat product according to any one of items 23 to 29, in which the sheet product achieves property (ii), and in which property (ii) is 175 MPa or less, or 170 MPa or less, or 165 MPa or less, or 160 MPa or less, or 155 MPa or less.

Item 31. An automotive seat product according to any one of items 23 to 30, in which the sheet product achieves property (iii), and in which property (iii) is 20 MPa or less, or 18 MPa or less, or 15 MPa or less, or 12 MPa or less, or 10 MPa or less, or 8 MPa or less.

Item 32. An automotive seat product according to any one of items 23 to 31, wherein the sheet product achieves property (iv), and wherein property (iv) is at least 235 MPa, or at least 240 MPa, or at least 250 MPa, or at least 255 MPa, or at least 260 MPa, or at least 265 MPa, or at least 270 MPa.

Item 33. An automotive seat product according to any one of items 23 to 32, wherein the sheet product achieves property (v), and wherein property (v) is at least 230 MPa, or at least 235 MPa, or at least 240 MPa, or at least 245 MPa, or at least 250 MPa.

Item 34. An automotive seat product according to any one of items 23 to 33, wherein the sheet product achieves property (vi), and wherein property (vi) is at least 350 MPa, or at least 355 MPa, or at least 360 MPa, or at least 365 MPa, or at least 370 MPa.

Item 35. An automotive seat product according to any one of items 23 to 34, wherein the sheet product achieves an elongation of at least 15%, or at least 18%, or at least 20%, or at least 22%, or at least 24%, or at least 26%, or at least 28% in temper T43.

Item 36. An automotive seat product according to any one of items 23 to 35, in which the sheet product achieves an elongation of at least 10%, or at least 12%, or at least 14%, or at least 16%, or at least 18%, or at least 20% after a paint baking treatment at 180°C for 20 minutes.

Item 37. An automotive seat product according to any one of items 23 to 36, wherein the sheet product achieves an elongation of at least 10%, or at least 11%, or at least 12%, or at least 13%, or at least 14%, or at least 15% after artificial aging at 180°C for 8 hours.

Item 38. An automotive sheet product according to any one of items 23 to 37, wherein the sheet product is resistant to intergranular corrosion.

Item 39. An automotive seat product according to any one of items 23 to 38, wherein the seat product is resistant to filiform corrosion.

Item 40. An automotive seat product according to any one of items 23 to 37, wherein the seat product is crack-free.

<vi. Miscellaneous matters>
These and other aspects, advantages, and novel features of the new technology are described in part in the description that follows, which will become apparent to those skilled in the art upon examination of the following description and drawings, or may be learned by practicing one or more embodiments of the technology provided by this disclosure.

Among those advantages and improvements disclosed, other objects and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings. Detailed embodiments of the present invention are disclosed herein; however, it should be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various forms. Moreover, the examples provided in connection with the various embodiments of the present invention are intended to be illustrative and not limiting.

Throughout the specification and claims, the following words take on the meanings clearly associated therewith, unless the context clearly dictates otherwise. As used herein, the phrases "in one embodiment" and "in some embodiments" do not necessarily refer to the same embodiment, although they may. Additionally, as used herein, the phrases "in another embodiment" and "in some other embodiments" do not necessarily refer to different embodiments, although they may. Thus, various embodiments of the invention may be readily combined without departing from the scope or spirit of the invention.

In addition, as used herein, the term "or" is an inclusive "or" modifier and is equivalent to the term "and/or" unless the context clearly dictates otherwise. The term "based on" is not exclusive and may be based on additional unrecited elements unless the context clearly dictates otherwise. Additionally, throughout this specification, "a," "an," and "the" include the plural meanings unless the context clearly dictates otherwise. "In" includes the meanings "in" and "on" unless the context clearly dictates otherwise.

While several embodiments of the present invention have been described, it should be understood that these embodiments are merely illustrative and not limiting, and that many variations may become apparent to those skilled in the art. Moreover, unless the context clearly dictates otherwise, the various steps may be performed in any desired order, and any applicable steps may be added and/or removed.

＊各合金の残部は、０．０２～０．０３重量％のＴｉ、アルミニウム、不可避元素及び不純物であって、各合金はいずれの一つの不純物も０．０３重量％以下で含有し、またそこで各合金はすべての不純物を合計で０．１０重量％以下含有した。
＊＊合金２９は、米国特許第６，５３７，３９２号に従ったＡＡ６０５５型の合金である。ＡＡ６０５５合金についての米国アルミニウム協会（Ｔｈｅ Ａｌｕｍｉｎｕｍ Ａｓｓｏｃｉａｔｉｏｎ）による組成の限度値は、以下の通りである：０．６～１．２重量％のＳｉ、０．３０（最大）重量％のＦｅ、０．５０～１．０重量％のＣｕ、０．１０（最大）重量％のＭｎ、０．７～１．１重量％のＭｇ、０．２０～０．３０重量％のＣｒ、０．５５～０．９重量％のＺｎ、０．１０（最大）重量％のＴｉ、０．０５（最大）重量％の不純物、合計０．１５（最大）重量％の他の不純物、残部のアルミニウム。（“Ｉｎｔｅｒｎａｔｉｏｎａｌ Ａｌｌｏｙ Ｄｅｓｉｇｎａｔｉｏｎｓ ａｎｄ Ｃｈｅｍｉｃａｌ Ｃｏｍｐｏｓｉｔｉｏｎ Ｌｉｍｉｔｓ ｆｏｒ Ｗｒｏｕｇｈｔ Ａｌｕｍｉｎｕｍ ａｎｄ Ｗｒｏｕｇｈｔ Ａｌｕｍｉｎｕｍ Ａｌｌｏｙｓ，” Ｊａｎｕａｒｙ ２０１５、第１０頁、Ｔｈｅ Ａｌｕｍｉｎｕｍ Ａｓｓｏｃｉａｔｉｏｎ， １５２５ Ｗｉｌｓｏｎ Ｂｏｕｌｅｖａｒｄ， Ａｒｌｉｎｇｔｏｎ， ＶＡ ２２２０９。）
合金１８、２１～２２及び２７は、発明の合金である。合金１～１７、１９～２０、及び２３～２６、及び２８～３０は、非発明の合金であり、灰色で強調している。 Thirty alloys were cast as 6 inch by 18 inch ingots. The compositions of these ingots are provided in Table 1 below.

*The balance of each alloy was 0.02-0.03 wt% Ti, Aluminum, unavoidable elements and impurities, with each alloy containing less than 0.03 wt% of any one impurity, and where each alloy contained less than 0.10 wt% of all impurities in total.
**Alloy 29 is an AA6055 type alloy in accordance with U.S. Patent No. 6,537,392. The Aluminum Association composition limits for AA6055 alloy are as follows: 0.6-1.2 wt.% Si, 0.30(max) wt.% Fe, 0.50-1.0 wt.% Cu, 0.10(max) wt.% Mn, 0.7-1.1 wt.% Mg, 0.20-0.30 wt.% Cr, 0.55-0.9 wt.% Zn, 0.10(max) wt.% Ti, 0.05(max) wt.% impurities, 0.15(max) wt.% total other impurities, balance Aluminum. (“International Alloy Designs and Chemical Composition Limits for Wrought Aluminum and Wrought Aluminum Alloys,” January 2015, page 10, The Aluminum Association, 1525 Wilson Boulevard, Arlington, VA 22209).
Alloys 18, 21-22 and 27 are invention alloys. Alloys 1-17, 19-20, 23-26 and 28-30 are non-invention alloys and are highlighted in grey.

＊合金２～４の値は、自然時効処理の６０日間後のものである。 The ingots were homogenized after casting and then rolled into final gauge sheet product. The final gauge sheet product had a thickness of 2 mm. The final gauge sheet product was then solution heat treated, quenched to room temperature, and then reheated to a pre-aging temperature of 82°C (179.6°F), and then subjected to a simulated coil cool by holding in a furnace programmed to cool at a predetermined cooling rate (following Newtonian cooling) to give the alloys temper T43. The natural aging response of the alloys was then evaluated by measuring the mechanical properties of each alloy at 7 and 90 days of natural aging (measured from the time the alloy was quenched after the solution heat treatment). The paint bake response of the T43 temper alloys was also tested by heating at 180°C for 20 minutes. The artificial aging response of the alloys was also tested by aging the T43 temper alloys at 180°C for 8 hours (T6 type temper). The experimental results are provided in Table 2 below, where all values shown are TYS-LT (transverse tensile yield strength) and are in MPa, NA = natural aging, PB = paint baked as above, and T6 = artificial aging as above.

*Values for alloys 2-4 are after 60 days of natural aging treatment.

Natural Aging Properties: As shown, non-invention alloys 1-8, 10, 16, 26, and 28 do not meet the TYS-LT parameters of ≤155 MPa after 7 days of natural aging and/or ≤175 MPa after 90 days of natural aging. Furthermore, the strength of non-invention alloys 8, 13, 17, 20, and 30 increased excessively (≥20 MPa) from 7 days to 90 days of natural aging. Achieving strengths of ≤155 MPa after 7 days of natural aging, ≤175 MPa after 90 days of natural aging, and ≤20 MPa increase in strength from 7 days to 90 days of natural aging is important for formability.
NOTE: Natural aging test data for the invention alloy 22 is not included because B557 test specimens for this alloy were inadequate for other unrelated reasons. However, based on additional testing, it is believed that alloy 22 will meet the requirements of TYS-LT ≤ 155 after 7 days of natural aging, TYS-LT ≤ 175 after 90 days of natural aging, and an increase in TYS-LT ≤ 20 MPa from 7 days to 90 days of natural aging.

<Paint bakeability>: As shown, non-invention alloys 9, 11, 13-15, 17, 20, 23 and 25 achieved insufficient strength after paint bake with TYS-LT less than 235 MPa 30 days after paint bake and/or TYS-LT less than 230 MPa 90 days after paint bake. The low strength after paint bake and loss of strength over time after paint bake are unacceptable for most automotive applications.

<Artificial Aging Properties>: As shown, non-invention alloys 9-10, 13-15, 20, 23, 25, and 30 all achieved poor artificial aging strength with TYS-LT less than 350 MPa after artificial aging. The low artificial aging strength may make the alloys unsuitable for some automotive applications.

Apart from the mechanical properties, the corrosion resistance of some alloys was also tested and the results are provided in Tables 3-4 below.

As shown, the intergranular corrosion resistance of these alloys is generally acceptable. However, the filiform corrosion of alloys 6-7, 10, 14 and 24 is excessively high based on maximum length, exceeding 0.30 inches. Alloy 12 is expected to behave similarly to alloys 10 and 14 with respect to filiform corrosion, and therefore is considered a non-invention alloy. Alloy 19 is expected to behave similarly to alloy 24 with respect to filiform corrosion, and therefore is considered a non-invention alloy.

These results suggest that alloying elements need to be used in specific combinations to achieve a combination of properties that may be important for aluminum alloy sheet products. Specifically, alloys with excess solutes (e.g., alloys 1-8, 25-26, 28) may achieve unacceptable strength and/or corrosion resistance. That is, the total amount of Si+Mg+Zn+Cu is limited to 4.25 wt.% or less. Specific amounts of silicon and magnesium are also important. Too little silicon (e.g., alloys 15 and 23) results in poor properties. Furthermore, the Mg:Si ratio needs to be 1.4 or less, as shown by alloys 15 and 25, where the poor strength was at least partially caused by a high Mg:Si ratio. Both copper and zinc need to be used in large amounts to achieve good strength and corrosion resistance. This is shown by contrasting inventive alloys 18, 21-22, and 27 with various non-inventive alloys. Finally, chromium should be avoided as it can negatively impact the underlying properties (according to Alloy 30) and can also affect the recyclability of the alloy.

Although various embodiments of the present disclosure have been described in detail, it is apparent that variations and modifications of those embodiments will occur to those skilled in the art. However, it should be expressly understood that such variations and modifications are within the spirit and scope of the present disclosure.

Claims (11)

1. An aluminium alloy sheet product comprising:
0.85 to 1.05 wt.% Si;
0.70 to 1.3 wt. % Mg;
where (wt. % of Mg)/(wt. % of Si) is not greater than 1.4 / 1;
0.70 to 3.0 wt. % Zn;
0.55 to 1.3 wt.% Cu;
wherein the total amount of Si+Mg+Zn+Cu is 4.25% by weight or less;
0.01 to 0.30 wt. % Fe;
Mn up to 0.70 wt.%;
% Cr max.
% Zr;
Maximum 0.20 wt.% V;
and max 0.25 wt.% Ti,
The balance is aluminum, optional unavoidable elements and impurities.
The aluminum alloy sheet product has a thickness of 1.0 to 4.0 mm. 2. The aluminum alloy sheet product of claim 1, wherein the aluminum alloy comprises at least 0.75 wt.% Mg . 3. The aluminum alloy sheet product of claim 2 , wherein the aluminum alloy comprises up to 1.25 wt.% Mg . 2. The aluminum alloy sheet product of claim 1, wherein (wt. % Mg)/(wt. % Si) is not greater than 1.3 / 1. 5. An aluminium alloy sheet product according to claim 4 , wherein (wt %) Mg/(wt %) Si is at least 0.7 /1 . The aluminum alloy sheet product of claim 1 , wherein the aluminum alloy comprises at least 0.75 wt.% Zn . 7. The aluminum alloy sheet product of claim 6 , wherein the aluminum alloy comprises up to 2.8 wt.% Zn . The aluminum alloy sheet product of claim 1 , wherein the aluminum alloy comprises at least 0.60 wt.% Cu . The aluminum alloy sheet product of claim 8 , wherein the aluminum alloy comprises up to 1.25 wt.% Cu . 10. An automotive seat product made from the aluminum alloy sheet product according to any one of claims 1 to 9 . 1. An aluminium alloy sheet product comprising:
0.85 to 1.05 wt.% Si;
0.80 to 1.10 wt. % Mg;
0.70 to 1.8 wt. % Zn;
0.70 to 1.05 wt.% Cu;
wherein the total amount of Si+Mg+Zn+Cu is 4.25% by weight or less;
0.01 to 0.30 wt. % Fe;
Mn up to 0.50 wt.%;
% Cr max.
% Zr;
Maximum 0.20 wt.% V;
and max 0.25 wt.% Ti,
The balance is aluminum, optional unavoidable elements and impurities.
The aluminum alloy sheet product has a thickness of 1.0 to 4.0 mm.