CN115433855A

CN115433855A - Aluminum extrusion with low carbon footprint

Info

Publication number: CN115433855A
Application number: CN202110606973.XA
Authority: CN
Inventors: 湛弘义; 王建锋; 王攀
Original assignee: GM Global Technology Operations LLC
Current assignee: GM Global Technology Operations LLC
Priority date: 2021-06-01
Filing date: 2021-06-01
Publication date: 2022-12-06
Also published as: DE102022103145A1; US20220380878A1

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 extrusion with 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

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

Components made from aluminum (Al) alloys have become increasingly popular in a variety of industries and applications, including general manufacturing, construction equipment, automotive or other transportation industries, household or industrial structures, aerospace, and the like. For example, al alloys are used in the manufacturing industry to extrude or be made from components having uniform cross-sectional geometries. 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 characteristics, 6000 series Al alloys are suitable for automotive applications.

The 6000 series Al alloy includes at least about 70 wt.% raw Al. The production of raw Al from bauxite results in the production of about 15-22 tons of carbon dioxide (CO) per ton of raw Al ₂ ) And (5) discharging. Increasing the use of Al scrap in the manufacture of Al extrudates will significantly reduce the carbon (C) footprint due to the CO associated with the pretreatment and re-melting of Al scrap ₂ The emission is only CO related to the production of the original Al ₂ About 5% of the emissions. 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 impact properties of the final product. Therefore, it would be beneficial to develop an Al alloy that has relatively high resistance to Fe impurities and exhibits high strength and fracture resistance.

Disclosure of 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 having a low C footprint.

In various aspects, the present techniques provide 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 (Z) at a concentration of greater than or equal to about 0.1 wt% to less than or equal to about 0.2 wt%, 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 or equal to about 0 wt%, and the balance of the alloy composition.

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

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

In one aspect, the alloy composition includes 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.%, wherein the combined concentration of Cr and Mn is less than or equal to about 0.45 wt.%.

In one aspect, an alloy composition has a first dispersoid including Zr and at least one of Si or Al and a second dispersoid including at least one of Si, fe, al and 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.

In one aspect, the alloy composition includes a reduced amount of an intermetallic phase comprising Fe 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 the form of billets or logs.

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 component selected from the group consisting of beams, bumpers, flooring (floor pan), battery cases, wheels, rocker arms, control arms, guide rails, reinforcement plates, treads, subframe members, pillars, and struts.

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 techniques also provide 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 ℃ 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 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 in a concentration of greater than or equal to about 0.5 wt% to less than or equal to about 1.5 wt%, mg in a concentration of greater than or equal to about 0.5 wt% to less than or equal to about 1.5 wt%, zr in a concentration of greater than or equal to about 0.1 wt% to less than or equal to about 0.2 wt%, fe in a concentration of greater than or equal to about 0.2 wt% to less than or equal to about 0.4 wt%, fe in a concentration of greater than or equal to about 0 wt% to less than or equal to about 0.3 wt%, cr in a concentration of greater than or equal to about 0 wt% to less than or equal to about 0.3 wt%, al in a concentration of greater than or equal to about 0.2 wt% to less than or equal to about 0.4 wt%, and Cu in a concentration of greater than or equal to about 0 wt% to about 0.2 wt% to less than or equal to about 0 wt%, and the balance of Al composition.

In one aspect, the 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 with a water mist at a cooling rate of greater than or equal to about 0.05 ℃/s.

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

In one aspect, prior to heating, the alloy composition is subjected to a homogenization process that includes heating the blank at a rate of greater than or equal to about 1 ℃/min to less than or equal to about 10 ℃/min until the alloy composition reaches a temperature of greater than or equal to about 500 ℃ to less than or equal to about 580 ℃, holding 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.

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

In various aspects, the present techniques also provide 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 ingot provides Si, mg, zr, cr, mn, cu, ti, and V; adding at least one raw Al ingot to the melt to form an alloy melt, wherein the alloy melt comprises a concentration of raw Al ingots of less than about 40 wt%, based on the total mass of the alloy melt; 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 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%, zr at a concentration of greater than or equal to about 0.05 wt% to less than or equal to about 0.2 wt%, fe at a concentration of greater than or equal to about 0.2 wt% to less than or equal to about 0.4 wt%, cr at a concentration of greater than or equal to about 0 wt% to less than or equal to about 0.3 wt%, 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%, V at a concentration of greater than or equal to about 0 wt% to less than or equal to about 0.2 wt%, and the balance of the alloy composition 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 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 embodiment 1, comprising:

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% to less than or equal to about 1 wt%; and

zr in a concentration of greater than or equal to about 0.12 wt.% to less than or equal to about 0.17 wt.%.

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

cr at 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.%.

4. The alloy composition of embodiment 3, comprising:

cr in a concentration of greater than or equal to about 0.1 wt% to less than or equal to about 0.25 wt%; and

mn in a concentration of greater than or equal to about 0.1 wt% to less than or equal to about 0.25 wt%,

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

5. The alloy composition of embodiment 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.

6. The alloy composition of embodiment 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.

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 billet or log form.

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 an automotive component selected from the group consisting of a beam, a bumper, a floor, a battery enclosure, a wheel, a rocker arm, a control arm, a guide rail, a stiffener, a step, a sub-frame member, a post, and a strut.

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 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:

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).

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 Si or Al; and

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

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

16. The method of embodiment 12, wherein the quenching is performed with a water mist at a cooling rate of greater than or equal to about 0.05 ℃/s.

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

18. The method of embodiment 12, wherein prior to the 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 ℃/min to less than or equal to about 10 ℃/min until the alloy composition reaches a temperature of greater than or equal to about 500 ℃ to less than or equal to about 580 ℃;

subjecting the alloy composition to the temperature for a period of time greater than or equal to about 0.5 hours to less than or equal to about 24 hours; and is

The alloy composition is quenched.

19. The method of embodiment 12, wherein the method produces per 1 ton formedThe extruded article has less than or equal to about 10 tons of carbon dioxide (CO) ₂ ) And (5) discharging.

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

forming a melt by melting post-consumer aluminum (Al) scrap;

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

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

Solidifying the cast alloy composition to form the alloy composition,

wherein 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%;

zr in a concentration of greater than or equal to about 0.05 wt.% to less than or equal to about 0.2 wt.%;

cr at a concentration of greater than or equal to about 0 wt% to less than or equal to about 0.3 wt%;

mn in 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%;

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 Al.

Further areas of applicability 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.

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 a graphical illustration showing a cross-section of an exemplary as-cast 6000 series Al alloy billet. The scale bar is 30 μm.

FIG. 2A is a graphical illustration of a comparative as-cast Al alloy billet having dispersoids embedded within a matrix. The scale bar is 0.2 μm.

Fig. 2B is a diagrammatic illustration of an exemplary comparative extruded article formed from the comparative as-cast Al alloy billet of fig. 2A. The scale bar is 1000 μm.

Fig. 3A is an illustration of an as-cast Al alloy billet having dispersoids embedded within a matrix, in accordance with aspects of the present technique. The scale bar is 0.5 μm.

Fig. 3B is an illustration of an exemplary extruded article formed from the as-cast Al alloy billet of fig. 3A, in accordance with aspects of the present technique. The scale bar is 1000 μm.

FIG. 4 is a flow diagram illustrating a method of forming an alloy composition in accordance with aspects of the present technique.

Fig. 5 is a flow diagram illustrating a method of forming an extruded article in accordance with aspects of the present technique.

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

Detailed Description

The exemplary embodiments are provided so that this disclosure will be thorough and will fully convey the scope to those 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 exemplary 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 example embodiments only and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises," "comprising," "including," and "having" are inclusive and therefore specify the presence of stated features, elements, compositions, steps, integers, operations, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. While the open-ended term "comprising" should be understood as a non-limiting term used to describe and claim the various embodiments described herein, in certain aspects the term may alternatively be understood as a more limiting and limiting term, such as "consisting of … …" or "consisting essentially of … …". Thus, for any given embodiment describing compositions, materials, components, elements, features, integers, operations, and/or method steps, the disclosure also specifically includes embodiments that consist of, or consist essentially of, such described compositions, materials, components, elements, features, integers, operations, and/or method steps. In the case of "consisting of … …," alternative embodiments exclude any additional compositions, materials, components, elements, features, integers, operations, and/or method steps, and in the case of "consisting essentially of … …," exclude from such embodiments any additional compositions, materials, components, elements, features, integers, operations, and/or method steps that substantially affect the basic and novel characteristics, but do not substantially affect the basic and novel characteristics may be included in the embodiments.

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 explicitly identified as such. It is also to be understood that additional or alternative steps may be employed, unless otherwise stated.

When a component, element, or layer is referred to as being "on," "engaged to," "connected to," or "coupled to" another element or layer, it may be directly on, engaged, connected, or coupled to the other 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 to," "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 similar manner (e.g., "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, these steps, elements, components, regions, layers and/or sections should not be limited by these terms unless otherwise specified. 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.

Spatially or temporally relative terms, such as "before", "after", "inner", "outer", "lower", "below", "lower", "upper", and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially or temporally relative terms may be intended to encompass different orientations of the device or system in use or operation in addition to the orientation depicted in the figures.

Throughout this disclosure, numerical values represent approximate measurements or range limits to encompass embodiments that slightly deviate from the given value and that substantially have the value mentioned, as well as embodiments that exactly have the value mentioned. Other than in the working examples provided at the end of the detailed description, all numerical values of parameters (e.g., amounts or conditions) in this specification (including the appended claims) are to be understood as being modified in all instances by the term "about", whether or not "about" actually appears before the numerical value. "about" means that the numerical value allows some slight imprecision (with some approach to exactness in the value; approximately or reasonably approximating the value; nearly). If the imprecision provided by "about" is not otherwise understood in the art with this ordinary meaning, then "about" as used herein refers to at least the deviation that may result from ordinary methods of measuring and using such parameters. For example, "about" can include a deviation of 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 in some aspects optionally less than or equal to 0.1%.

In addition, the disclosure of a range includes all values within the full range and further sub-ranges, including the endpoints and sub-ranges given for these ranges.

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

To reduce costs 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 may be used in place of at least a portion of the virgin Al. Currently, the recovered 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 extrudates, post-consumer Al scrap (e.g., used beverage cans) needs to be applied because the volume of pre-consumer Al scrap is limited and may not meet demand. Post-consumer Al scrap, however, has a high Fe content in the Al alloy of greater than about 0.15 wt.%, which is undesirable for certain applications such as extruded articles for automobiles.

High Fe content can produce intermetallic compounds, also referred to 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 a graphical 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 ingot 10 comprises Mg ₂ A first intermetallic phase 12 of Si, a second intermetallic phase 14 of α -AlFeSi and a third intermetallic phase 16 of β -AlFeSi. The first intermetallic phase 12 dissolves during the homogenization 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 prone to cracking. Although they are important for the formation of dispersoids during the homogenization heat treatment, the increased content of Cr and Mn, for example in the 6082 Al alloy, also contributes to the formation of intermetallic phases containing Fe.

Accordingly, the present technology provides an alloy composition formed from Al scrap, such as post-consumer Al scrap, that is substantially free of intermetallic phases including Fe, has good mechanical properties, and can be processed with a lower C footprint relative to the original Al alloy.

The alloy composition includes 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%, such as about 0.5 wt%, about 0.6 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%.

The alloy composition also includes 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.%, such as about 0.5 wt.%, about 0.6 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.%.

The alloy composition also includes 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.%, such as 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.%.

The alloy composition also includes 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.%. At least a portion of the Fe is provided by the Al scrap, as discussed in more detail herein.

The alloy composition optionally includes Cr and Mn at separate and independent concentrations of greater than or equal to about 0 wt% to less than or equal to about 0.3 wt%, greater than or equal to about 0.05 wt% to less than or equal to about 0.3 wt%, or greater than or equal to about 0.1 wt% to less than or equal to about 0.25 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%, 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%, about 0.30 wt%. 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.%, i.e., greater than about 0.05 wt.% to less than or equal to about 0.45 wt.%.

The alloy composition also optionally includes 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%, such as 0 wt%, about 0.1 wt%, about 0.2 wt%, about 0.3 wt%, about 0.4 wt%, about 0.5 wt%, about 0.6 wt%, about 0.7 wt%, about 0.8 wt%, about 0.9 wt%, or about 1 wt%.

The alloy composition also optionally includes 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%.

The alloy composition also optionally includes 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%.

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

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 not intended to add other components to the alloy composition, unavoidable impurities, for example, in individual and independent concentrations of less than or equal to about 0.5 wt%, may be included.

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 (e.g., al window frames), or other scrap Al materials. Post-consumer Al scrap provides the above-mentioned Fe levels, which are higher than those found in 6000-series Al alloy extrudates provided for automotive purposes.

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

The as-cast billet has a reduced content (i.e., at least about a 20% reduced content) of intermetallic phases (also referred to as "Fe-containing intermetallic phases") comprising Fe and at least one of Si, cr, mn, or Al relative to a comparative as-cast 6082 Al alloy billet having the same or substantially the same Fe content (e.g., within about 0.1% or about 0.05%). Fe interacts with Si and Al to form intermetallic phases during casting. During casting, cr and Mn atoms in the melt may 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 Cr and Mn concentrations, i.e., at the concentrations described herein, and including Zr, the content of Fe-containing intermetallic phases in the alloy composition may 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 decreases from 0.25 wt% to 0.13 wt%, wherein the mole fraction is determined using model calculations based on thermodynamics. However, low Fe containing Al alloys are associated with a high C footprint. In the alloy compositions of the present technology (last row of table 1) including at least about 60% post-consumer Al scrap, the mole fraction of Fe-containing intermetallic compounds is significantly reduced (by greater than 20%) when Zr is included, and the combined concentration of Cr and Mn is reduced relative to high Fe-containing Al alloys. 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 low Fe containing Al alloys made from the initial casting (raw Al casting).

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

Si

Mg

Zr

Cr

Mn

Fe

Al

Molar fraction of Fe-intermetallic compound

Low [ Fe ]]Al alloy of

0.85 By weight%

0.8 By weight%

-

0.13 By weight%

0.45 Weight percent

0.13 By weight%

Balance of

0.76%

High [ Fe ]]Al alloy of

0.85 By weight%

0.8 By weight%

-

0.13 By weight%

0.45 Weight percent

0.25 By weight%

Balance of

1.08%

Alloy composition

0.85 By weight%

0.8 By weight%

0.13 By weight%

0.2 By weight%

0.25 By weight%

Balance of

0.79%

For extruded articles with high strength and impact performance requirements, such as automotive parts, cr and Mn may be included to perform on the as-cast billetPromotes the precipitation of dispersoids containing Al (Fe, M) Si during the homogenization heat treatment of (1), wherein M is Cr and/or Mn. Thus, the as-cast billet comprises a dispersoid embedded within a matrix defined by the alloy composition. Dispersoids are nanoparticles having a diameter, i.e., an average longest diameter, of greater than or equal to about 30 nm to less than or equal to about 100 nm. Similarly, zr can precipitate dispersoids comprising Zr and at least one of Si or Al, e.g. (Al, si) ₃ Zr nano-particles. Thus, in some aspects, the alloy composition comprises a first dispersoid that comprises, consists essentially of, or consists of: at least one of Si, fe, al and Cr or Mn; a second dispersoid that comprises, 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 an extruded article. When extruded, the alloy composition has a unique deformed microstructure defining a fibrous structure in the absence of recrystallization, as the presence of dispersoids hinders recrystallization of the deformed microstructure. For example, fig. 2A is an illustration of an exemplary comparative as-cast Al alloy billet 20 having dispersoids 22 embedded within a matrix 24. Fig. 2B is a diagrammatic 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 dispersoids, the comparative extruded article 26 has a recrystallized microstructure of large grain size (e.g., 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 an extruded article 36 formed from the as-cast billet 30. Here, the as-cast billet 30 has a sufficiently high volume of dispersoids such that the extruded article 36 has a unique fibrous texture with elongated platelets aligned in the direction of extrusion.

As a non-limiting example, the extruded article may be a vehicle part or a building part. Non-limiting examples of vehicles having components suitable for production from the alloy composition include automobiles, motorcycles, bicycles, boats, tractors, busesMobile 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 a beam, a bumper, a floor, a battery enclosure, a wheel, a rocker arm, a control arm, a guide rail, a stiffener, a step, a sub-frame member, a pillar, and a strut. Accordingly, the present technology also provides an automotive part or other extruded article comprising the alloy composition. The extruded articles exhibit a yield strength of greater than or equal to about 280 MPa, an elongation at break of greater than or equal to about 8% when stretched in an extrusion direction during a tensile test, and a ion beam weight of greater than or equal to about 100 ^ based on a VDA238-100 bend test (sample size 60 mm X60 mm X t mm; punch radius (punch radius) 0.4 mm; bend line perpendicular to extrusion direction) at maximum load

The bending angle of (c).

Referring to fig. 4, the present technique also provides a method 40 of forming the alloy composition into a round billet 41. 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. Method 40 then includes adding at least one raw 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 and at least one of Cr, mn, cu, ti, or V. The at least one raw Al ingot 48 and/or the at least one master alloy ingot may also provide a portion of the Fe. The alloy melt comprises a raw Al ingot 48 at a concentration of less than about 40 wt.% based on the total mass of the alloy melt (i.e., the alloy melt comprises greater than or equal to about 60 wt.% post-consumer Al scrap) and each additional element at a predetermined concentration within the individual element ranges described herein. The method 40 further 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 billet 41 comprising the composition described above.

Referring to fig. 5, as a non-limiting example, the present technique also provides a method 50 for forming an extruded article 52, depicted as a bumper beam. The method 50 includes subjecting the round stock 41 cast as discussed with reference to fig. 4 to a homogenization heat treatment process that includes heating the round stock 41 at a rate of greater than or equal to about 1 ℃/min to less than or equal to about 10 ℃/min until the round stock 41 reaches a temperature of greater than or equal to about 500 ℃ to less than or equal to about 580 ℃, subjecting 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 fan or spray quenching the alloy composition. As mentioned above, the homogenization heat treatment results in precipitation of the dispersoids. Furthermore, homogenized log billet 41 has a reduced content of intermetallic phases comprising Fe relative to a comparative 6082 Al log billet having the same Fe content.

The method 50 then includes heating the log blank 41 to a temperature of greater than or equal to about 450 ℃ to less than or equal to about 550 ℃ or greater than or equal to about 470 ℃ to less than or equal to about 500 ℃ to form a heated log blank 41. The heating may be performed by heating the round bar stock 41 in an oven, for example.

After heating, the method 50 includes extruding the heated log blank 41 through a die to form a heated extruded article. The die includes a slot that matches the cross-sectional geometry of the article being manufactured. Thus, the heated extruded article has a cross-sectional geometry defined by the die. Extrusion is performed 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.

Next, the method 50 includes quenching the heated extruded article to form an extruded article 52. Quenching is performed at a rate fast enough to avoid the formation of undesirable precipitates, but not so fast as to cause cracking or deformation. Thus, 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 ℃/s or greater than or equal to about 1 ℃/s. Quenching is carried out by any method capable of cooling at the rates described above, such as by contacting the heated extruded part with water or a cold water mist.

The method then optionally includes aging the extruded article 52. Aging comprises heating the extruded article 52 to a temperature of greater than or equal to about 120 ℃ to less than or equal to about 250 ℃, greater than or equal to about 130 ℃ to less than or equal to about 200 ℃, or greater than or equal to about 175 ℃ to less than or equal to about 185 ℃, such as at a temperature of about 120 ℃, about 125 ℃, about 130 ℃, about 135 ℃, about 140 ℃, about 145 ℃, about 150 ℃, about 155 ℃, about 160 ℃, about 165 ℃, about 170 ℃, about 175 ℃, about 180 ℃, about 185 ℃, about 190 ℃, about 195 ℃, about 200 ℃, about 205 ℃, about 210 ℃, about 215 ℃, about 220 ℃, about 225 ℃, about 230 ℃, about 235 ℃, about 240 ℃, about 245 ℃, or about 250 ℃. Aging is carried out for a time 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 hours, 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 then quenched.

In various aspects of the present technique, the method 50 further comprises at least one of: stretching the extruded article 52 to improve the flatness of the extruded article 52 prior to aging; discarding a portion from each end of the extruded article 52 before or after aging because the extruded article 52 has a discard length of less than or equal to about 5 inches, less than or equal to about 2.5 inches, or less than or equal to about 1 inch; cutting the extruded article 52 to a desired size (e.g., it is contemplated that multiple objects may be cut to form a length of extruded article 52); etching the extruded article 52; anodizing the extruded article 52; or the extruded article 52 may be further processed, such as by bending or debossing into a desired shape.

Forming the extruded article 52 results in CO relative to a corresponding process performed with a raw Al alloy and without post-consumer Al scrap ₂ The equivalent weight reduction is at least about 50%, at least about 70%, or at least about 90%. In some aspectsThe method produces about 10 tons, about 5 tons, or about 3 tons of CO per 1 ton of extruded alloy composition ₂ And (5) discharging.

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 may also be changed in many ways. Such variations 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

1. An alloy composition comprising:

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

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,

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:

wherein the alloy composition comprises:

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