CN115433855A - Aluminum extrusions with a low carbon footprint - Google Patents

Abstract

The invention discloses an aluminum extrudate having a low carbon footprint. An alloy composition is provided. The alloy composition includes about 0.5 wt.% to about 1.5 wt.% silicon (Si), about 0.5 wt.% to about 1.5 wt.% magnesium (Mg), about 0.1 wt.% to about 0.2 wt.% zirconium (Zr), about 0.2 wt.% to about 0.4 wt.% iron (Fe), 0 wt.% to about 0.3 wt.% chromium (Cr), 0 wt.% to about 0.3 wt.% manganese (Mn), about 0 wt.% to about 1 wt.% copper (Cu), about 0 wt.% to about 0.2 wt.% titanium (Ti), about 0 wt.% to about 1 wt.% vanadium (V), and the balance aluminum (Al). Greater than or equal to about 60% of the alloy composition is from Al scrap. Methods of forming the alloy composition and methods of forming extruded articles from the composition are also provided.

Description

Aluminum extrusions with a low carbon footprint

technical field

The present invention relates to an alloy composition, a method of forming an extruded article, and a method of forming an alloy composition.

Background technique

This section provides background information related to the present disclosure which is not necessarily prior art.

Components made of aluminum (Al) alloys have become increasingly common in a variety of industries and applications, including general manufacturing, construction equipment, automotive or other transportation industries, domestic or industrial structures, aerospace, and more. For example, Al alloys are used in the manufacturing industry to extrude or be made from parts with uniform cross-sectional geometry. In particular, 6000 series Al alloys can be processed by extrusion, heat treatment, and/or welding, and exhibit high strength and corrosion resistance. With these properties, the 6000 series Al alloys are suitable for automotive applications.

The 6000 series Al alloys include at least about 70% by weight primary Al. The production of primary Al from bauxite results in about 15-22 tons of carbon dioxide (CO ₂ ) emissions per ton of primary Al. Increased use of Al scrap in the manufacture of Al extrudates will significantly reduce the carbon (C) footprint, as the _CO2 emissions associated with preprocessing and remelting of Al scrap are only about 5 _% of those associated with raw Al production %. However, the iron (Fe) impurity content in Al scrap can be much higher than the Fe content in 6000 series Al alloys used in automotive Al extrusions, which is detrimental to the fracture toughness and crash performance of the final product. Therefore, it would be beneficial to develop an Al alloy that has relatively high tolerance to Fe impurities and exhibits high strength and fracture resistance.

Contents of the invention

This section provides a general summary of the disclosure and is not a comprehensive disclosure of its full scope or all of its features.

The present disclosure relates to Al extrudates with a low C footprint.

In various aspects, the present technology provides an alloy composition comprising silicon (Si) at a concentration of greater than or equal to about 0.5 wt. % to less than or equal to about 1.5 wt. Magnesium (Mg) at about 1.5% by weight, Zirconium (Z) at a concentration of about 0.1% by weight or more to about 0.2% by weight or less, Fe at a concentration of about 0.2% by weight or more to about 0.4% by weight or less , chromium (Cr) at a concentration of greater than or equal to about 0% by weight to less than or equal to about 0.3% by weight, manganese (Mn) at a concentration of greater than or equal to about 0% by weight to less than or equal to about 0.3% by weight, at a concentration of greater than 0% by weight Copper (Cu) to less than or equal to about 1 wt. %, titanium (Ti) at a concentration of greater than 0 wt. % to less than or equal to about 0.2 wt. %, vanadium (V ), and the balance of the alloy composition is Al.

In one aspect, the alloy composition comprises Si at a concentration of greater than or equal to about 0.7 wt. % to less than or equal to about 1 wt. %, Mg at a concentration of greater than or equal to about 0.7 wt. Zr equal to about 0.12 wt % to less than or equal to about 0.17 wt %.

In one aspect, the alloy composition comprises at least one of Cr at a concentration of greater than or equal to about 0.05% by weight to less than or equal to about 0.3% by weight or Mn at a concentration of greater than or equal to about 0.05% by weight to less than or equal to about 0.3% by weight .

In one aspect, the alloy composition comprises Cr at a concentration greater than or equal to about 0.1 wt. % to less than or equal to about 0.25 wt. % and Mn at a concentration greater than or equal to about 0.1 wt. % to less than or equal to about 0.25 wt. The combined concentration is less than or equal to about 0.45% by weight.

In one aspect, the alloy composition has a first dispersoid comprising Zr and at least one of Si or Al and a second dispersoid comprising Si, Fe, Al and at least one of Cr or Mn, Wherein the first and second dispersoids have individual diameters of greater than or equal to about 30 nm to less than or equal to about 100 nm.

In one aspect, the alloy composition comprises a reduced amount of Fe-containing intermetallic phase relative to a comparative 6082 alloy composition having substantially the same Fe concentration.

In one aspect, greater than or equal to about 60% of the alloy composition is from post-consumer Al scrap.

In one aspect, the alloy composition is in billet or log form.

In one aspect, the alloy composition is in the form of an extruded article having a fibrous structure defined by the alloy composition.

In one aspect, the extruded article is an automotive vehicle selected from the group consisting of beams, bumpers, floor pans, battery housings, wheels, rockers, control arms, rails, stiffeners, steps, subframe members, pillars, and struts. part.

In one aspect, the extruded article has a yield strength of greater than or equal to about 280 MPa and an elongation at break of greater than or equal to about 8%.

In various aspects, the present technology also provides a method of forming an extruded article, the method comprising heating a billet having an alloy composition to a temperature of greater than or equal to about 450°C to less than or equal to about 550°C to form a heated a billet, extruding the heated billet through a die to form a heated extruded article, and quenching the heated extruded article to form an extruded article having a fibrous structure defined by the alloy composition, Wherein the alloy composition comprises Si at a concentration of greater than or equal to about 0.5% by weight to less than or equal to about 1.5% by weight, Mg at a concentration of greater than or equal to about 0.5% by weight to less than or equal to about 1.5% by weight, a concentration of greater than or equal to about 1.5% by weight 0.1 wt% to less than or equal to about 0.2 wt% Zr, concentration greater than or equal to about 0.2 wt% to less than or equal to about 0.4 wt% Fe, concentration greater than or equal to about 0 wt% to less than or equal to about 0.3 wt% Cr, Mn at a concentration of greater than or equal to about 0 wt % to less than or equal to about 0.3 wt %, Cu at a concentration of greater than 0 wt % to less than or equal to about 1 wt %, at a concentration of greater than 0 wt % to less than or equal to about 0.2 wt % Ti, V at a concentration greater than 0% by weight to less than or equal to about 0.2% by weight, and the balance of the alloy composition is Al.

In one aspect, greater than or equal to about 60% of the alloy composition is from post-consumer Al scrap.

In one aspect, the alloy composition has a first dispersoid comprising Zr and at least one of Si or Al and a second dispersoid comprising Si, Fe, Al and at least one of Cr or Mn, Wherein the first and second dispersoids have individual diameters of greater than or equal to about 30 nm to less than or equal to about 100 nm.

In one aspect, extrusion is performed with a ram at an extrusion speed of greater than or equal to about 4 ipm to less than or equal to about 20 ipm.

In one aspect, quenching is performed by water spray at a cooling rate greater than or equal to about 0.05°C/s.

In one aspect, the method further comprises aging the extruded article by heating the extruded article to a temperature of greater than or equal to about 120° C. to less than or equal to about 250° C. for a period of greater than or equal to about 0.5 hour to less than or equal to about 20 hours .

In one aspect, prior to heating, the alloy composition is subjected to a homogenization process comprising heating the billet at a rate of greater than or equal to about 1 °C/min to less than or equal to about 10 °C/min until the alloy composition reaches a temperature greater than or a temperature of about 500°C to less than or equal to about 580°C, maintaining the alloy composition at the temperature for greater than or equal to about 0.5 hour to less than or equal to about 24 hours, and quenching the alloy composition.

In one aspect, the method produces less than or equal to about 10 tons of C footprint per 1 ton of extruded article formed.

In various aspects, the present technology also provides a method of forming an alloy composition, the method comprising forming a melt by melting post-consumer Al scrap; adding at least one master alloy ingot to the melt, wherein the at least one Master alloy ingots provide Si, Mg, Zr, Cr, Mn, Cu, Ti, and V; at least one primary Al ingot is added to the melt to form an alloy melt, wherein the alloy melt contains A raw Al ingot having a concentration of less than about 40% by weight of the total mass of the body; casting the alloy melt in a direct chill process to form a cast alloy composition; and solidifying the cast alloy composition to form an alloy composition, wherein the The alloy composition comprises Si at a concentration of greater than or equal to about 0.5 wt. % to less than or equal to about 1.8 wt. %, Mg at a concentration of greater than or equal to about 0.5 wt. % to less than or equal to about 1.5 wt. to less than or equal to about 0.2 weight percent Zr, greater than or equal to about 0.2 weight percent to less than or equal to about 0.4 weight percent Fe, greater than or equal to about 0 weight percent to less than or equal to about 0.3 weight percent Cr, concentration Mn at a concentration of greater than or equal to about 0 wt% to less than or equal to about 0.3 wt%, Cu at a concentration of greater than 0 wt% to less than or equal to about 1 wt%, Ti at a concentration of greater than 0 wt% to less than or equal to about 0.2 wt%, The alloy composition is V at a concentration greater than 0 wt. % to less than or equal to about 0.2 wt. %, and the balance is Al.

The invention discloses the following embodiments:

1. An alloy composition comprising:

Silicon (Si) at a concentration of greater than or equal to about 0.5 wt. % to less than or equal to about 1.5 wt. %;

Magnesium (Mg) at a concentration of greater than or equal to about 0.5% by weight to less than or equal to about 1.5% by weight;

Zirconium (Zr) in a concentration of greater than or equal to about 0.1 wt. % to less than or equal to about 0.2 wt. %;

Iron (Fe) at a concentration of greater than or equal to about 0.2% by weight to less than or equal to about 0.4% by weight;

Chromium (Cr) in a concentration of greater than or equal to about 0% by weight to less than or equal to about 0.3% by weight;

Manganese (Mn) at a concentration of greater than or equal to about 0% by weight to less than or equal to about 0.3% by weight;

Copper (Cu) in a concentration greater than 0% by weight to less than or equal to about 1% by weight;

Titanium (Ti) in a concentration greater than 0% by weight to less than or equal to about 0.2% by weight;

Vanadium (V) in a concentration greater than 0% by weight to less than or equal to about 0.2% by weight; and

The balance of the alloy composition is aluminum (Al).

2. The alloy composition of embodiment 1, comprising:

Si at a concentration of greater than or equal to about 0.7% by weight to less than or equal to about 1% by weight;

Mg at a concentration of greater than or equal to about 0.7% by weight to less than or equal to about 1% by weight; and

Zr at a concentration of greater than or equal to about 0.12 weight percent to less than or equal to about 0.17 weight percent.

3. The alloy composition of embodiment 1, comprising at least one of the following:

Cr at a concentration of greater than or equal to about 0.05% by weight to less than or equal to about 0.3% by weight; or

Mn at a concentration of greater than or equal to about 0.05% by weight to less than or equal to about 0.3% by weight.

4. The alloy composition of embodiment 3, comprising:

Cr at a concentration of greater than or equal to about 0.1 wt. % to less than or equal to about 0.25 wt. %; and

Mn at a concentration of greater than or equal to about 0.1% by weight to less than or equal to about 0.25% by weight,

wherein the combined concentration of Cr and Mn is less than or equal to about 0.45% by weight.

5. The alloy composition of embodiment 1, wherein the alloy composition further comprises:

A first dispersoid comprising Zr and at least one of both Si or Al; and

A second dispersoid comprising at least one of Si, Fe, Al and Cr or Mn,

wherein the first and second dispersoids have individual diameters greater than or equal to about 30 nm and less than or equal to about 100 nm.

6. The alloy composition of embodiment 1, wherein the alloy composition comprises a reduced amount of Fe-containing intermetallic phase relative to a comparative 6082 alloy composition having substantially the same Fe concentration.

7. The alloy composition of embodiment 1, wherein greater than or equal to about 60% of the alloy composition is from post-consumer Al scrap.

8. The alloy composition of embodiment 1 in the form of a billet or a rod.

9. The alloy composition of embodiment 1 in the form of an extruded article having a fibrous structure defined by the alloy composition.

10. The alloy composition of embodiment 9, wherein the extruded article is selected from the group consisting of beams, bumpers, floors, battery housings, wheels, rocker arms, control arms, rails, stiffeners, treads, subframes Automotive components of members, columns and struts.

11. The alloy composition of embodiment 9, wherein the extruded article has a yield strength of greater than or equal to about 280 MPa and an elongation at break of greater than or equal to about 8%.

12. A method of forming an extruded article, the method comprising:

heating the billet comprising the alloy composition to a temperature of greater than or equal to about 450°C to less than or equal to about 550°C to form a heated billet;

extruding the heated billet through a die to form a heated extruded article; and

quenching the heated extruded article to form an extruded article having a fibrous structure defined by the alloy composition,

Wherein said alloy composition comprises:

Silicon (Si) at a concentration of greater than or equal to about 0.5 wt. % to less than or equal to about 1.5 wt. %;

Magnesium (Mg) at a concentration of greater than or equal to about 0.5% by weight to less than or equal to about 1.5% by weight;

Zirconium (Zr) in a concentration of greater than or equal to about 0.1 wt. % to less than or equal to about 0.2 wt. %;

Iron (Fe) at a concentration of greater than or equal to about 0.2% by weight to less than or equal to about 0.4% by weight;

Chromium (Cr) in a concentration of greater than or equal to about 0% by weight to less than or equal to about 0.3% by weight;

Manganese (Mn) at a concentration of greater than or equal to about 0% by weight to less than or equal to about 0.3% by weight;

Copper (Cu) in a concentration greater than 0% by weight to less than or equal to about 1% by weight;

Titanium (Ti) in a concentration greater than 0% by weight to less than or equal to about 0.2% by weight;

Vanadium (V) in a concentration greater than 0% by weight to less than or equal to about 0.2% by weight; and

The balance of the alloy composition is aluminum (Al).

13. The method of embodiment 12, wherein greater than or equal to about 60% of the alloy composition is from post-consumer Al scrap.

14. The method of embodiment 12, wherein the alloy composition comprises:

A first dispersoid comprising Zr and at least one of both Si or Al; and

A second dispersoid comprising at least one of Si, Fe, Al and Cr or Mn,

wherein the first and second dispersoids have individual diameters greater than or equal to about 30 nm and less than or equal to about 100 nm.

15. The method of embodiment 12, wherein the extruding is performed using a ram at an extrusion speed of greater than or equal to about 4 inches/minute to less than or equal to about 20 inches/minute.

16. The method of embodiment 12, wherein the quenching is performed by water spray at a cooling rate of greater than or equal to about 0.05 °C/s.

17. The method of embodiment 12, further comprising heating the extruded article to a temperature of greater than or equal to about 120° C. to less than or equal to about 250° C. for greater than or equal to about 0.5 hours to less than or equal to about 20 hours to age the extruded article.

18. The method of embodiment 12, wherein prior to said heating, subjecting said alloy composition to a homogenization process comprising:

heating the billet at a rate of greater than or equal to about 1°C/min to less than or equal to about 10°C/min until the alloy composition reaches a temperature of greater than or equal to about 500°C to less than or equal to about 580°C;

maintaining the alloy composition at the temperature for greater than or equal to about 0.5 hours to less than or equal to about 24 hours; and

Quenching the alloy composition.

19. The method of embodiment 12, wherein the method produces carbon dioxide (CO ₂ ) emissions less than or equal to about 10 tons per 1 ton of the extruded article formed.

20. A method of forming an alloy composition, the method comprising:

Melt formation by melting post-consumer aluminum (Al) scrap;

At least one master alloy ingot is added to the melt, wherein the at least one master alloy ingot provides silicon (Si), magnesium (Mg), zirconium (Zr), chromium (Cr), manganese (Mn), copper (Cu ), titanium (Ti) and vanadium (V);

adding at least one primary Al ingot to the melt to form an alloy melt, wherein the alloy melt comprises the primary Al ingot at a concentration of less than about 40% by weight based on the total mass of the alloy melt;

casting said alloy melt in a direct chill process to form a cast alloy composition; and

solidifying the cast alloy composition to form the alloy composition,

Wherein said alloy composition comprises:

Si at a concentration of greater than or equal to about 0.5% by weight to less than or equal to about 1.8% by weight;

Mg at a concentration of greater than or equal to about 0.5% by weight to less than or equal to about 1.5% by weight;

Zr at a concentration of greater than or equal to about 0.05% by weight to less than or equal to about 0.2% by weight;

Iron (Fe) at a concentration of greater than or equal to about 0.2% by weight to less than or equal to about 0.4% by weight;

Cr at a concentration of greater than or equal to about 0% by weight to less than or equal to about 0.3% by weight;

Mn at a concentration of greater than or equal to about 0% by weight to less than or equal to about 0.3% by weight;

Cu at a concentration greater than 0% by weight to less than or equal to about 1% by weight;

Ti at a concentration greater than 0% by weight to less than or equal to about 0.2% by weight;

V at a concentration of greater than 0% by weight to less than or equal to about 0.2% by weight; and

The balance of the alloy composition is Al.

Other areas of application will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

Description of drawings

The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

FIG. 1 is an illustration showing a cross-section of an exemplary as-cast 6000 series Al alloy billet. Scale bar is 30 μm.

Figure 2A is a graphical illustration of a comparative as-cast Al alloy billet with dispersoids embedded in the matrix. Scale bar is 0.2 μm.

Figure 2B is an illustration of an exemplary comparative extruded article formed from the comparative cast Al alloy billet of Figure 2A. Scale bar is 1000 μm.

3A is an illustration of an as-cast Al alloy billet having a dispersoid embedded in a matrix in accordance with various aspects of the present technology. Scale bar is 0.5 μm.

3B is an illustration of an exemplary extruded article formed from the as-cast Al alloy billet of FIG. 3A in accordance with various aspects of the present technology. Scale bar is 1000 μm.

4 is a flowchart illustrating a method of forming an alloy composition in accordance with various aspects of the present technology.

5 is a flowchart illustrating a method of forming an extruded article according to various aspects of the present technology.

Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.

detailed description

Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth, such as examples of specific compositions, components, devices and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known methods, well-known device structures, and well-known technologies are not described in detail.

The terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" may be intended to include the plural forms as well, unless the context clearly dictates otherwise. The terms "comprising", "including", "comprising" and "having" are inclusive and thus specify the presence of stated features, elements, compositions, steps, integers, operations and/or parts but do not exclude a or the presence or addition of multiple other features, integers, steps, operations, elements, parts and/or groups thereof. Although the open-ended term "comprising" should be understood as a non-limiting term used to describe and claim various embodiments described herein, in certain aspects, the term may alternatively be understood to be more Restrictive and qualifying terms such as "consisting of" or "consisting essentially of". Thus, for any given embodiment that recites a composition, material, part, element, feature, integer, operation and/or method step, the present disclosure also specifically includes or consists essentially of such recited composition, material, part , elements, features, integers, operations and/or method steps. Where "consisting of", alternative embodiments exclude any additional compositions, materials, parts, elements, features, integers, operations and/or method steps, while where "consisting essentially of , any additional compositions, materials, parts, elements, features, integers, operations and/or method steps that materially affect the basic and novel properties are excluded from such embodiments, but do not materially affect any of the basic and novel properties Compositions, materials, parts, elements, features, integers, operations and/or method steps may be comprised in an embodiment.

Any method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless expressly identified as an order of performance. It is also to be understood that additional or alternative steps may be employed unless otherwise stated.

When a part, element or layer is referred to as being "on," "engaged," "connected" or "coupled" to another element or layer, it can be directly on another part, element or layer On, engaged, connected or coupled to another component, element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being directly on, "directly engaged with," "directly connected to" or "directly coupled to" another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (eg, "between" versus "directly between," "adjacent" versus "directly adjacent," etc.). As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Although the terms first, second, third, etc. may be used herein to describe various steps, elements, components, regions, layers and/or sections, unless otherwise stated, these steps, elements, components, regions, layers and and/or sections should not be limited by these terms. These terms may be only used to distinguish one step, element, component, region, layer or section from another step, element, component, region, layer or section. Terms such as "first," "second," and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first step, element, component, region, layer or section discussed below could be termed a second step, element, component, region, layer or section without departing from the teachings of the example embodiments.

For ease of description, relative terms in space or time may be used herein, such as "before", "after", "inside", "outside", "under", "below", "lower", "upper", "Upper" and the like describe the relationship of one element or feature to other element(s) or feature(s) as shown in the figures. Spatially or temporally relative terms may be intended to encompass different orientations of the device or system in use or operation than the orientation shown in the figures.

Throughout this disclosure, numerical values represent approximate measurements or range limits to encompass slight deviations from a given value and embodiments approximately having the stated value as well as embodiments having exactly the stated value. Except in the working examples provided at the end of the detailed description, all numerical values of parameters (such as amounts or conditions) in this specification (including the appended claims) are to be understood as being modified in all cases by the term "about", regardless of Whether "approximately" actually appears before the value. "About" means that the stated value allows for some slight imprecision (with some approximation to the value's exact value; approximately or reasonably approximately the value; nearly). If the imprecision provided by "about" is not understood in the art other than this ordinary meaning, then "about" is used herein to mean at least a deviation that may result from ordinary methods of measuring and using such parameters. For example, "about" can include less than or equal to 5%, optionally less than or equal to 4%, optionally less than or equal to 3%, optionally less than or equal to 2%, optionally less than or equal to 1%, optionally less than or equal to 0.5%, and optionally less than or equal to 0.1% in some respects.

Furthermore, disclosure of ranges includes disclosure of all values within the entire range and disclosure of further subdivided ranges including endpoints and subranges given for those ranges.

Exemplary embodiments will now be described more fully with reference to the accompanying drawings.

To reduce cost and reduce the C footprint associated with extruded 6000 series Al alloys made from virgin Al with low Fe content (typically less than or equal to about 0.15 wt %), Al scrap can be used to replace at least a portion of the virgin Al. Currently, the recycled mass content of 6000 series Al alloys is only about 10 to about 30 wt%, and only pre-consumer Al scrap from the manufacturing process is used. To reduce the C footprint associated with Al extrusions, post-consumer Al scrap (e.g., used beverage cans) needs to be applied, as pre-consumer Al scrap is limited in volume and cannot meet demand. However, post-consumer Al scrap has a high Fe content of greater than about 0.15% by weight in the Al alloy, which is undesirable for certain applications such as extrusions for automobiles.

High Fe content can produce intermetallic compounds, also known as "intermetallic phases" (longest diameter greater than or equal to about 1 μm), which initiate cracks and reduce fatigue strength, ductility and fracture toughness. For example, FIG. 1 is an illustration showing a cross-section of an exemplary as-cast 6000 series Al alloy billet 10 having a high Fe content. The as-cast 6000 series Al alloy blank 10 comprises a first intermetallic phase 12 consisting of Mg2Si, a _second intermetallic phase 14 consisting of α-AlFeSi, and a third intermetallic phase 16 consisting of β-AlFeSi. The first intermetallic phase 12 dissolves during the homogenizing heat treatment after casting. The second and third intermetallic phases 14, 16 remaining in the product after extrusion from the as-cast 6000 series Al alloy billet 10 cause the product extruded from the as-cast 6000 series Al alloy billet 10 to be susceptible to cracking. Although they are important for homogenizing the formation of dispersoids during heat treatment, increased contents of Cr and Mn, such as in 6082 Al alloy, also contribute to the formation of Fe-containing intermetallic phases.

Accordingly, the present technology provides an alloy composition formed from Al scrap, such as post-consumer Al scrap, that is substantially free of Fe-containing intermetallic phases, has good mechanical properties, and can be compared to virgin Al alloys at Low C footprint processing.

The alloy composition comprises Si at a concentration of greater than or equal to about 0.5 wt. % to less than or equal to about 1.5 wt. % or greater than or equal to about 0.7 wt. % to less than or equal to about 1 wt. About 0.7 wt%, about 0.8 wt%, about 0.9 wt%, about 1 wt%, about 1.1 wt%, about 1.2 wt%, about 1.3 wt%, about 1.4 wt%, or about 1.5 wt% Si.

The alloy composition further comprises Mg at a concentration of greater than or equal to about 0.5 wt. % to less than or equal to about 1.5 wt. % or greater than or equal to about 0.7 wt. % to less than or equal to about 1 wt. , about 0.7 wt%, about 0.8 wt%, about 0.9 wt%, about 1 wt%, about 1.1 wt%, about 1.2 wt%, about 1.3 wt%, about 1.4 wt%, or about 1.5 wt% Mg.

The alloy composition further comprises Zr at a concentration of greater than or equal to about 0.1 wt. % to less than or equal to about 0.2 wt. %, or greater than or equal to about 0.12 wt. % to less than or equal to about 0.17 wt. %, about 0.12 wt%, about 0.13 wt%, about 0.14 wt%, about 0.15 wt%, about 0.16 wt%, about 0.17 wt%, about 0.18 wt%, about 0.19 wt%, or about 0.2 wt% of Zr.

The alloy composition further comprises Fe at a concentration of greater than or equal to about 0.2 wt % to less than or equal to about 0.4 wt %, such as about 0.2 wt %, about 0.225 wt %, about 0.25 wt %, about 0.275 wt %, about 0.3 wt %, About 0.325 wt%, about 0.35 wt%, about 0.375 wt%, or about 0.4 wt% Fe. At least a portion of the Fe is provided by Al scrap, as discussed in more detail herein.

The alloy composition optionally comprises Cr and Mn in separate and independent concentrations of greater than or equal to about 0% by weight to less than or equal to about 0.3% by weight, greater than or equal to about 0.05% by weight to less than or equal to about 0.3% by weight, Or greater than or equal to about 0.1% by weight to less than or equal to about 0.25% by weight, such as 0% by weight, about 0.05% by weight, about 0.06% by weight, about 0.07% by weight, about 0.08% by weight, about 0.09% by weight, about 0.1% by weight %, about 0.11 wt%, about 0.12 wt%, about 0.13 wt%, about 0.14 wt%, about 0.15 wt%, about 0.16 wt%, about 0.17 wt%, about 0.18 wt%, about 0.19 wt%, about 0.2 wt% %, about 0.21 wt%, about 0.22 wt%, about 0.23 wt%, about 0.24 wt%, about 0.25 wt%, about 0.26 wt%, about 0.27 wt%, about 0.28 wt%, about 0.29 wt%, or about 0.30 weight%. When both Cr and Mn are present in the alloy composition, they have a combined concentration of less than or equal to about 0.45 wt%, ie, a combined concentration of greater than about 0.05 wt% to less than or equal to about 0.45 wt%.

The alloy composition also optionally comprises Cu at a concentration of greater than or equal to about 0 wt. % to less than or equal to about 1 wt. % or greater than or equal to about 0.1 wt. % to less than or equal to about 0.5 wt. % by weight, about 0.2 % by weight, about 0.3 % by weight, about 0.4 % by weight, about 0.5 % by weight, about 0.6 % by weight, about 0.7 % by weight, about 0.8 % by weight, about 0.9 % by weight, or about 1 % by weight Cu .

The alloy composition also optionally comprises Ti at a concentration of greater than or equal to about 0 wt % to less than or equal to about 0.2 wt %, such as 0 wt %, about 0.05 wt %, about 0.06 wt %, about 0.07 wt %, about 0.08 wt % %, about 0.09 wt%, about 0.1 wt%, about 0.11 wt%, about 0.12 wt%, about 0.13 wt%, about 0.14 wt%, about 0.15 wt%, about 0.16 wt%, about 0.17 wt%, about 0.18 wt% %, about 0.19 wt%, or about 0.2 wt% of Ti.

The alloy composition also optionally comprises V at a concentration of greater than or equal to about 0 wt % to less than or equal to about 0.2 wt %, such as 0 wt %, about 0.05 wt %, about 0.06 wt %, about 0.07 wt %, about 0.08 wt % %, about 0.09 wt%, about 0.1 wt%, about 0.11 wt%, about 0.12 wt%, about 0.13 wt%, about 0.14 wt%, about 0.15 wt%, about 0.16 wt%, about 0.17 wt%, about 0.18 wt% %, about 0.19 wt%, or about 0.2 wt% of V.

The balance of the alloy composition is Al. In various aspects, Al is present at a concentration of greater than or equal to about 95% by weight.

In various aspects, the alloy composition comprises, consists essentially of, or consists of: Si, Mg, Zr, Fe, Cr, Mn, Cu, Ti, V, and Al; Si, Mg, Zr, Fe, Mn, Cu, Ti, V and Al; Si, Mg, Zr, Fe, Cr, Cu, Ti, V and Al; Si, Mg, Zr, Fe, Cr, Mn, Ti, V and Al; Si, Mg, Zr, Fe, Mn, Ti, V and Al; Si, Mg, Zr, Fe, Cr, Ti, V and Al; Si, Mg, Zr, Fe, Cr, Mn, Cu, V and Al; Si, Mg, Zr, Fe, Mn, Cu, V and Al; Si, Mg, Zr, Fe, Cr, Cu, V and Al; Si, Mg, Zr, Fe, Cr, Mn, Cu, Ti and Al; Si, Mg, Zr, Fe, Mn, Cu, Ti and Al; Si, Mg, Zr, Fe, Cr, Cu, Ti and Al; Si, Mg, Zr, Fe, Cr, Mn, V and Al; Si, Mg, Zr, Fe, Mn, V and Al; Si, Mg, Zr, Fe, Cr, V and Al; Si, Mg, Zr, Fe, Cr, Mn, Cu and Al; Si, Mg, Zr, Fe, Mn, Cu and Al; Si, Mg, Zr, Fe, Cr, Cu and Al; Si, Mg, Zr, Fe, Cr, Mn, Ti and Al; Si, Mg, Zr, Fe, Mn, Ti and Al; Si, Mg, Zr, Fe, Cr, Ti and Al; Si, Mg, Zr, Fe, Cr, Mn and Al; Si, Mg, Zr, Fe, Mn and Al; Si, Mg, Zr, Fe, Cr and Al; Si, Mg, Zr, Fe, Cu, Ti, V and Al; Si, Mg, Zr, Fe, Ti, V and Al; Si, Mg, Zr, Fe, Cu, V and Al; Si, Mg, Zr, Fe, Cu, Ti and Al; Si, Mg, Zr, Fe, Cu, and Al; Si, Mg, Zr, Fe, Ti, and Al; Si, Mg, Zr, Fe, V, and Al; or Si, Mg, Zr, Fe, and Al . As used herein, the term "consisting essentially of" means that although no other components are intended to be added to the alloy composition, a single and independent concentration of unavoidable impurities may be included, for example, less than or equal to about 0.5% by weight.

Greater than or equal to about 60% of the alloy composition is from post-consumer Al scrap, such as from Al beverage cans, Al building components (eg, Al window frames), or other scrap Al materials. Post-consumer Al scrap provides the aforementioned Fe levels, which are higher than those found in 6000 series Al alloy extrudates supplied for automotive purposes.

In some aspects, the alloy composition is in the form of a billet, such as a rod cast from an alloy melt.

The as-cast billet has a reduced content (i.e., a content that is at least about 20% reduced) containing An intermetallic phase of Fe and at least one of Si, Cr, Mn, or Al (also referred to as "Fe-containing intermetallic phase"). Fe interacts with Si and Al to form intermetallic phases during casting. During the casting process, Cr and Mn atoms in the melt can replace Fe atoms in the Fe-containing intermetallic phase to form an Al(Fe,M)Si intermetallic phase, where M is Cr and/or Mn. Thus, by maintaining low concentrations of Cr and Mn, ie, at the concentrations described herein, and including Zr, the amount of Fe-containing intermetallic phases in the alloy composition can be reduced or minimized. Table 1 shows comparative Al alloys with relatively high and low concentrations of Fe. The table shows that the mole fraction of the Fe-containing intermetallic phase decreases significantly when the Fe content is reduced from 0.25 wt% to 0.13 wt%, where the mole fraction is determined using thermodynamic-based model calculations. However, low Fe-containing Al alloys are associated with a high C footprint. In alloy compositions of the present technology that include at least about 60% post-consumer Al scrap (last row of Table 1), the mole fraction of Fe-containing intermetallics is significantly lower (to greater than 20%) when Zr is included, and Cr The combined concentrations of Mn and Mn are reduced relative to Al alloys with high Fe content. Therefore, by reducing the combined content of Cr and Mn and including Zr, the alloy composition maintains high strength and exhibits excellent crack resistance. Advantageously, the alloy composition has a much lower C footprint relative to Fe-low Al alloys made from initial casting (primary Al casting).

Table 1. Exemplary compositions and corresponding mole fractions of Fe-containing intermetallic microstructures.

Si Mg Zr Cr mn Fe Al Mole fraction of Fe-intermetallic compound Low [Fe] Al alloys 0.85% by weight 0.8% by weight - 0.13% by weight 0.45% by weight 0.13% by weight margin 0.76% Al alloys with high [Fe] 0.85% by weight 0.8% by weight - 0.13% by weight 0.45% by weight 0.25% by weight margin 1.08% alloy composition 0.85% by weight 0.8% by weight 0.13% by weight 0.2% by weight 0.2% by weight 0.25% by weight margin 0.79%

For extruded products with high strength and crash performance requirements, such as automotive parts, Cr and Mn may be included to promote the precipitation of dispersoids containing Al(Fe,M)Si during the homogenizing heat treatment of the as-cast billet, wherein M is Cr and/or Mn. Thus, the as-cast billet includes a dispersoid embedded within a matrix defined by the alloy composition. A dispersoid is a nanoparticle having a diameter, ie, an average longest diameter greater than or equal to about 30 nm to less than or equal to about 100 nm. Similarly, Zr is capable of precipitating dispersoids comprising Zr and at least one of Si or Al, such as (Al,Si) ₃ Zr nanoparticles. Thus, in some aspects, the alloy composition comprises a first dispersoid comprising, consisting essentially of, or consisting of: Si, Fe, Al, and at least one of Cr or Mn; a second dispersoid, It comprises, consists of, consists essentially of, or consists of: Zr and at least one of Si or Al; or a combination thereof.

The alloy composition is suitable for extrusion into extruded articles. When extruded, the alloy composition has a unique deformed microstructure defining a fibrous structure in the absence of recrystallization because the presence of the dispersoid hinders recrystallization of the deformed microstructure. For example, FIG. 2A is an illustration of an exemplary comparative as-cast Al alloy billet 20 having a dispersoid 22 embedded within a matrix 24 . FIG. 2B is an illustration of an exemplary comparative extruded article 26 formed from a comparative as-cast Al alloy billet 20 . Because the comparative as-cast Al alloy billet 20 has a low volume dispersoid, the comparative extruded article 26 has a recrystallized microstructure with a large grain size (eg, about 500 μm) defining a non-fibrous structure. In contrast, FIG. 3A is an illustration of an as-cast billet 30 comprising a prior art alloy composition and having a dispersoid 32 embedded within a matrix 34 . FIG. 3B is an illustration of extruded article 36 formed from as-cast billet 30 . Here, the as-cast billet 30 has a sufficiently high volume of dispersoid such that the extruded article 36 has a unique fibrous structure having elongated lamellae aligned along the direction of extrusion.

的弯曲角度。As non-limiting examples, the extruded article may be a vehicle component or a building component. Non-limiting examples of vehicles having components suitable for production from the alloy composition include automobiles, motorcycles, bicycles, boats, tractors, buses, mobile homes, campers, gliders, airplanes, and military vehicles such as tanks. In various aspects of the present technology, the extruded article is an automotive component selected from the group consisting of beams, bumpers, floor panels, battery housings, wheels, rockers, control arms, rails, stiffeners, steps, subframe members, pillars, and struts . Accordingly, the present technology also provides automotive parts or other extruded articles comprising the alloy composition. When stretched in the direction of extrusion during a tensile test, the extruded article exhibits a yield strength of greater than or equal to about 280 MPa, an elongation at break of greater than or equal to about 8%, and a bending test based on VDA238-100 ( The sample size is 60 mm × 60 mm × t mm; the punch radius (punch radius) is 0.4 mm; the bending line is perpendicular to the direction of extrusion) greater than or equal to about 100/

the bending angle.

Referring to FIG. 4 , the present technology also provides a method 40 of forming an alloy composition into a round stock 41 . The method 40 includes forming a melt by melting post-consumer Al scrap, such as Al beverage cans 42 , scrap Al window frames 44 , and/or other Al scrap 46 . Post-consumer Al scrap contains higher Fe content than most 6000 series Al alloys. The method 40 then includes adding at least one primary Al ingot 48 and at least one master alloy ingot (not shown) to the melt to form an alloy melt, wherein the at least one master alloy ingot provides Si, Mg and Zr as well as Cr, Mn, Cu , Ti or V at least one. At least one primary Al ingot 48 and/or at least one master alloy ingot may also provide a portion of Fe. The alloy melt comprises primary Al ingot 48 at a concentration of less than about 40% by weight based on the total mass of the alloy melt (i.e., the alloy melt comprises greater than or equal to about 60% by weight post-consumer Al scrap) and the individual element ranges described herein Each additional element within a predetermined concentration. The method 40 also includes casting the alloy melt in a direct chill process to form a cast alloy composition, and solidifying the cast alloy composition to form a round stock 41 comprising the above composition.

Referring to FIG. 5 , as a non-limiting example, the present technology also provides a method 50 for forming an extruded article 52 , depicted as a bumper beam. The method 50 includes subjecting a log billet 41 cast as discussed with reference to FIG. billet 41 until the round stock billet 41 reaches a temperature of greater than or equal to about 500°C to less than or equal to about 580°C, the alloy composition is held at this temperature for greater than or equal to about 0.5 hours to less than or equal to about 24 hours, and the fan or spray-hardened alloy compositions. As mentioned above, the homogenizing heat treatment leads to the precipitation of dispersoids. Furthermore, the homogenized log stock 41 has a reduced content of Fe-containing intermetallic phases relative to the comparative 6082 Al log stock with the same Fe content.

The method 50 then includes heating the log stock 41 to a temperature of greater than or equal to about 450°C to less than or equal to about 550°C or greater than or equal to about 470°C to less than or equal to about 500°C to form the heated log stock 41. Heating can be performed, for example, by heating the round material blank 41 in a furnace.

After heating, method 50 includes extruding heated log stock 41 through a die to form a heated extruded article. The die includes slots that match the cross-sectional geometry of the article being manufactured. Thus, the heated extruded article has a cross-sectional geometry defined by the die. Carried out by pushing the alloy composition through a die with a ram at an extrusion speed of greater than or equal to about 4 inches per minute (ipm) to less than or equal to about 20 ipm, or greater than or equal to about 7 ipm to less than or equal to about 10 ipm extrude.

Next, method 50 includes quenching the heated extruded article to form extruded article 52 . Quenching is performed at a rate fast enough to avoid the formation of undesirable precipitates, but not so fast that cracking or deformation occurs. Accordingly, quenching includes reducing the temperature of the heated extruded article to ambient temperature at a rate of greater than or equal to about 0.05 °C/s or greater than or equal to about 1 °C/s. Quenching is performed by any method capable of cooling at the above-mentioned rates, such as by contacting the heated extruded part with water or a cool spray of water.

The method then optionally includes aging the extruded article 52 . Aging includes heating extruded article 52 to a temperature of greater than or equal to about 120° C. to less than or equal to about 250° C., greater than or equal to about 130° C. °C, for example at about 120°C, about 125°C, about 130°C, about 135°C, about 140°C, about 145°C, about 150°C, about 155°C, about 160°C, about 165°C, about 170°C, About 175°C, about 180°C, about 185°C, about 190°C, about 195°C, about 200°C, about 205°C, about 210°C, about 215°C, about 220°C, about 225°C, about 230°C, about 235°C °C, a temperature of about 240 °C, about 245 °C, or about 250 °C. Aging is performed for a period of greater than or equal to about 0.5 hours to less than or equal to about 20 hours, greater than or equal to about 1 hour to less than or equal to about 10 hours, or greater than or equal to about 4 hours to less than or equal to about 8 hours, such as about 0.5 hour, about 1 hour, about 1.5 hours, about 2 hours, about 2.5 hours, about 3 hours, about 3.5 hours, about 4 hours, about 4.5 hours, about 5 hours, about 6 hours, about 7 hours, about 8 hours, About 9 hours, about 10 hours, about 11 hours, about 12 hours, about 13 hours, about 14 hours, about 15 hours, about 16 hours, about 17 hours, about 18 hours, about 19 hours, or about 20 hours. The extruded article 52 is subsequently quenched.

In various aspects of the present technology, method 50 further includes at least one of: prior to aging, stretching extruded article 52 to improve the flatness of extruded article 52; A portion of each end is discarded because the extruded article 52 has a discarded length of about 5 inches or less, about 2.5 inches or less, or about 1 inch or less; the extruded article 52 is cut to a desired size (e.g. , it is contemplated that multiple objects may be cut to form lengths of extrusion 52 ); etching extrusion 52 ; anodizing extrusion 52 ; or further processing extrusion 52 , such as by bending or denting into a desired shape.

Forming extruded article 52 results in a _CO equivalent reduction of at least about 50%, at least about 70%, or at least about 90% relative to a corresponding process performed with virgin Al alloy and without post-consumer Al scrap. In some aspects, the method produces about 10 tons, about 5 tons, or about 3 tons of _CO2 emissions per 1 ton of extruded alloy composition.

The foregoing description of the embodiments has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not explicitly shown or described. The same content can also be changed in many ways. Such alterations are not to be regarded as a departure from the disclosure and all such modifications are intended to be included within the scope of the disclosure.

Claims (10)

1. An alloy composition comprising:

silicon (Si) at a concentration of greater than or equal to about 0.5 wt% to less than or equal to about 1.5 wt%;

magnesium (Mg) at a concentration of greater than or equal to about 0.5 wt% to less than or equal to about 1.5 wt%;

zirconium (Zr) at a concentration of greater than or equal to about 0.1 wt.% to less than or equal to about 0.2 wt.%;

iron (Fe) at a concentration of greater than or equal to about 0.2 wt.% to less than or equal to about 0.4 wt.%;

chromium (Cr) at a concentration of greater than or equal to about 0 wt% to less than or equal to about 0.3 wt%;

manganese (Mn) at a concentration of greater than or equal to about 0 wt% to less than or equal to about 0.3 wt%;

copper (Cu) at a concentration of greater than 0 wt% to less than or equal to about 1 wt%;

titanium (Ti) at a concentration of greater than 0 wt% to less than or equal to about 0.2 wt%;

vanadium (V) at a concentration of greater than 0 wt% to less than or equal to about 0.2 wt%; and is provided with

The balance of the alloy composition is aluminum (Al).

2. The alloy composition of claim 1, comprising at least one of:

cr in a concentration of greater than or equal to about 0.05 wt% to less than or equal to about 0.3 wt%; or

Mn in a concentration of greater than or equal to about 0.05 wt.% to less than or equal to about 0.3 wt.%.

3. The alloy composition of claim 1, wherein the alloy composition further comprises:

a first dispersoid comprising Zr and at least one of Si or Al; and

a second dispersoid comprising Si, fe, al and at least one of Cr or Mn,

wherein the first and second dispersoids individually have a diameter of greater than or equal to about 30 nm to less than or equal to about 100 nm.

4. The alloy composition of claim 1, wherein the alloy composition comprises a reduced amount of an intermetallic phase comprising Fe relative to a comparative 6082 alloy composition having substantially the same Fe concentration.

5. The alloy composition of claim 1, wherein greater than or equal to about 60% of the alloy composition is from post-consumer Al scrap.

6. The alloy composition of claim 1 in billet or log form.

7. The alloy composition of claim 1 in the form of an extruded article having a fibrous structure defined by the alloy composition.

8. The alloy composition of claim 7, wherein the extruded article is an automotive component selected from the group consisting of beams, bumpers, flooring, battery cases, wheels, rocker arms, control arms, guide rails, reinforcement plates, treads, sub-frame members, pillars, and struts.

9. The alloy composition of claim 9, wherein the extruded article has a yield strength of greater than or equal to about 280 MPa and an elongation at break of greater than or equal to about 8%.

10. A method of forming an extruded article, the method comprising:

heating a billet comprising the alloy composition to a temperature of greater than or equal to about 450 ℃ to less than or equal to about 550 ℃ to form a heated billet;

extruding the heated billet through a die to form a heated extruded article; and is

Quenching the heated extruded article to form an extruded article having a fibrous texture defined by the alloy composition,

wherein the alloy composition comprises:

silicon (Si) at a concentration of greater than or equal to about 0.5 wt% to less than or equal to about 1.5 wt%;

magnesium (Mg) at a concentration of greater than or equal to about 0.5 wt% to less than or equal to about 1.5 wt%;

zirconium (Zr) at a concentration of greater than or equal to about 0.1 wt.% to less than or equal to about 0.2 wt.%;

iron (Fe) at a concentration of greater than or equal to about 0.2 wt.% to less than or equal to about 0.4 wt.%;

chromium (Cr) at a concentration of greater than or equal to about 0 wt% to less than or equal to about 0.3 wt%;

manganese (Mn) at a concentration of greater than or equal to about 0 wt% to less than or equal to about 0.3 wt%;

copper (Cu) at a concentration of greater than 0 wt% to less than or equal to about 1 wt%;

titanium (Ti) at a concentration of greater than 0 wt% to less than or equal to about 0.2 wt%;

vanadium (V) at a concentration of greater than 0 wt% to less than or equal to about 0.2 wt%; and is

The balance of the alloy composition is aluminum (Al).

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