Patent Application
20220380878
This application claims the benefit and priority of Chinese Application No. 202110606973.X, filed Jun. 1, 2021. The entire disclosure of the above application is incorporated herein by reference.
This section provides background information related to the present disclosure which is not necessarily prior art.
Components made of aluminum (Al) alloys have become ever more prevalent in various industries and applications, including general manufacturing, construction equipment, automotive or other transportation industries, home or industrial structures, aerospace, and the like. For example, Al alloys are used in manufacturing industries for extruding parts that have uniform cross-sectional geometries or are made from parts 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.
6000 series Al alloys include at least about 70 wt. % primary Al. The manufacture of primary Al from bauxite ore results in about 15-22 tons of carbon dioxide (CO2) emission per ton of primary Al produced. Increased usage of Al scrap in the manufacturing of Al extrusion will reduce the carbon (C) footprint significantly because CO2 emission associated with the pre-processing and re-melting of Al scrap is only about 5% of the CO2 emission associated with primary Al production. However, the content of iron (Fe) impurities in Al scrap may be much higher than the content of Fe content in 6000 series Al alloys used in automotive Al extrusion, which is detrimental to fracture toughness and crash performance of the final product. Therefore, it would be beneficial to develop an Al alloy having a relatively high tolerance to Fe impurities and that exhibits high strength and fracture resistance.
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 extrusions with a low C footprint.
In various aspects, the current technology provides an alloy composition including 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. %, 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 a balance of the alloy composition being Al.
In one aspect, the alloy composition includes the Si at a concentration of greater than or equal to about 0.7 wt. % to less than or equal to about 1 wt. %, the Mg at a concentration of greater than or equal to about 0.7 wt. % to less than or equal to about 1 wt. %, and the 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 the 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 the 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 the 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 the Mn at 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 the Cr and the Mn is less than or equal to about 0.45 wt. %.
In one aspect, the alloy composition has a first dispersoid including Zr and at least one of Si or Al and a second dispersoid including 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 includes a reduced amount of intermetallic phases including 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 derived from post-consumer Al scrap.
In one aspect, the alloy composition is in the form of a billet or a log.
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 automobile part selected from the group consisting of a beam, bumper, a floor pan, a battery enclosure, a wheel, a rocker, a control arm, a rail, a reinforcement panel, a step, a subframe member, a pillar, and a strut.
In one aspect, the extruded article has a yield strength of greater than or equal to about 280 MPa and an elongation to fracture of greater than or equal to about 8%.
In various aspects, the current technology also provides a method of forming an extruded article, the method including 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 billet, extruding the heated billet through a die to form a heated extruded article, and quenching the heated extruded article to form the extruded article, the extruded article having a fibrous structure defined by the alloy composition, wherein 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. %, 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 0.1 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. %, 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 0 wt. % to less than or equal to about 0.2 wt. %, and a balance of the alloy composition being Al.
In one aspect, greater than or equal to about 60% of the alloy composition is derived from post-consumer Al scrap.
In one aspect, the alloy composition has a first dispersoid including Zr and at least one of Si or Al and a second dispersoid including 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 extruding is performed with a ram at a ram speed of greater than or equal to about 4 ipm to less than or equal to about 20 ipm.
In one aspect, the quenching is performed by water mist at a cooling rate of greater than or equal to about 0.05° C./s.
In one aspect, the method further includes 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 time of greater than or equal to about 0.5 hours to less than or equal to about 20 hours.
In one aspect, prior to the heating, the alloy composition is subjected to a homogenization process including 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.
In one aspect, the method generates less than or equal to about 10 tons of C footprint per 1 ton of the extruded article that is formed.
In various aspects, the current technology further provides a method of forming an alloy composition, the method including 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 primary Al ingot to the melt to form an alloy melt, wherein the alloy melt includes the primary Al ingot at a concentration of less than about 40 wt. % based on the total mass of the alloy melt; casting the alloy melt in a direct-chilled tooling to form a casted alloy composition; and solidifying the casted alloy composition to form the alloy composition, wherein 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 1.8 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 0 wt. % to less than or equal to about 0.2 wt. %, and a balance of the alloy composition being 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.
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.
Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.
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 processes, 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” may be 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. Although the open-ended term “comprising,” is to be understood as a non-restrictive term used to describe and claim various embodiments set forth herein, in certain aspects, the term may alternatively be understood to instead be a more limiting and restrictive term, such as “consisting of” or “consisting essentially of.” Thus, for any given embodiment reciting compositions, materials, components, elements, features, integers, operations, and/or process steps, the present disclosure also specifically includes embodiments consisting of, or consisting essentially of, such recited compositions, materials, components, elements, features, integers, operations, and/or process steps. In the case of “consisting of,” the alternative embodiment excludes any additional compositions, materials, components, elements, features, integers, operations, and/or process steps, while in the case of “consisting essentially of,” any additional compositions, materials, components, elements, features, integers, operations, and/or process steps that materially affect the basic and novel characteristics are excluded from such an embodiment, but any compositions, materials, components, elements, features, integers, operations, and/or process steps that do not materially affect the basic and novel characteristics can be included in the 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 specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed, unless otherwise indicated.
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 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 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 like fashion (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 indicated. 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,” “beneath,” “below,” “lower,” “above,” “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, the numerical values represent approximate measures or limits to ranges to encompass minor deviations from the given values and embodiments having about the value mentioned as well as those having exactly the value mentioned. Other than in the working examples provided at the end of the detailed description, all numerical values of parameters (e.g., of quantities 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” indicates that the stated numerical value allows some slight imprecision (with some approach to exactness in the value; approximately or reasonably close to 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 indicates at least variations that may arise from ordinary methods of measuring and using such parameters. For example, “about” may comprise a variation 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 certain aspects, optionally less than or equal to 0.1%.
In addition, disclosure of ranges includes disclosure of all values and further divided ranges within the entire range, including endpoints and sub-ranges given for the ranges.
Example embodiments will now be described more fully with reference to the accompanying drawings.
In order to decrease costs and reduce the C footprint associated with extruding 6000 series Al alloys having a low Fe content (generally less than or equal to about 0.15 wt. %) made from primary Al, Al scrap can be used to replace at least a portion of the primary Al. Currently, the recycled content by mass of 6000 series Al alloys is only about 10 wt. % to about 30 wt. % and only pre-consumer Al scrap from manufacturing processes is utilized. In order to reduce the C footprint associated with Al extrusions, applying post-consumer Al scrap (e.g., used beverage cans) is required as the volume of pre-consumer Al scrap is limited and cannot satisfy demand. However, post-consumer Al scrap has a high Fe content of greater than about 0.15 wt. % in Al alloys, which is undesirable for certain applications, such as for extruded articles for automobiles.
The high Fe content can generate intermetallic compounds, also referred to as “intermetallic phases” (having a longest diameter of greater than or equal to about 1μm), that initiate cracks and decrease fatigue strength, ductility, and fracture toughness. For example,
Accordingly, the current technology provides an alloy composition formed from Al scrap, such as post-consumer Al scrap, that is substantially free of intermetallic phases comprising Fe, has good mechanical properties, and can be processed with a lower C footprint relative to primary Al alloys.
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. %, such as at 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 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. %, such as at 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 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. %, such as at 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 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 at 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 Al scrap, as discussed in more detail herein.
The alloy composition optionally includes Cr and Mn at individual 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 at 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. %, or about 0.3 wt. %. When both of the Cr and Mn are present in the alloy composition, they have a combined concentration that is less than or equal to about 0.45 wt. %, i.e., 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. %, such as at 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 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 at 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 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 at 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. %.
A 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 “consists essentially of” means that although no other component is intentionally added to the alloy composition, unavoidable impurities may be included, for example, at individual and independent concentrations of less than or equal to about 0.5 wt. %.
Greater than or equal to about 60% of the alloy composition is derived from post-consumer Al scrap, such as from Al beverage cans, Al architectural components (e.g., Al window frames), or other scrap Al material. The post-consumer Al scrap provides the above-described Fe levels, which are higher than the Fe levels found in 6000 series Al alloy extrusions provided for automotive purposes.
In some aspects, the alloy composition is in the form of a billet, e.g., a log casted from an alloy melt.
The as-cast billet has a reduced content, i.e., at least about 20% reduced content, of intermetallic phases comprising Fe and at least one of Si, Cr, Mn, or Al (also referred to as a “Fe-bearing intermetallic phase”) relative to a comparative as-cast 6082 Al alloy billet that has the same or substantially the same (e.g., within about 0.1% or about 0.05%) Fe content. Fe interacts with Si and Al to form intermetallic phases during casting. Cr and Mn atoms in a melt can substitute for Fe atoms in Fe-bearing intermetallic phases during a casting process to form an Al(Fe,M)Si intermetallic phase, where M is Cr and/or Mn. Therefore, by keeping the concentrations of Cr and Mn low, i.e., to the concentrations described herein, and including Zr, the content of intermetallic phases comprising Fe in the alloy composition can be reduced or minimized. Table 1 shows comparative Al alloys having relatively high and low concentrations of Fe. This table shows that when the Fe content is lowered from 0.25 wt. % to 0.13 wt. %, the mole fraction of Fe-containing intermetallic phases decreases substantially, where the mole fractions are determined computationally using a thermodynamic-based model. However, the low Fe-containing Al alloy is associated with a high C footprint. In the alloy composition of the current technology (last row of Table 1), which includes at least about 60% post-consumer Al scrap, the mole fraction of Fe-containing intermetallics decreases substantially (by greater than 20%) when Zr is included and the combined concentration of Cr and Mn is decreased relative to the high Fe-containing Al alloy. Therefore, by reducing a combined content of Cr and Mn and including Zr, the alloy composition retains a high strength and exhibits excellent resistance to cracking. Beneficially, the alloy composition has a much lower C footprint relative to the low Fe-containing Al alloy made from a primary Al casting.
For extruded articles, such as automobile components, having high strength and crash performance requirements, Cr and Mn can be included to promote precipitation of dispersoids comprising Al(Fe, M)Si, where M is Cr and/or Mn, during homogenization heat treatment conducted on the as-cast billet. As such, the as-cast billet comprises dispersoids embedded within a matrix defined by the alloy composition. The dispersoids are nanoparticles having diameters, i.e., average longest diameters, of greater than or equal to about 30 nm to less than or equal to about 100 nm. Similarly, Zr enables precipitation of dispersoids comprising Zr and at least one of Si or Al, e.g., (Al, Si)3Zr nanoparticles. Therefore, 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 comprising, consisting essentially of, or consisting of Zr and at least one of Si or Al; or a combination thereof.
The alloy composition is suitable to be extruded into an extruded article. When extruded, the alloy composition has a unique deformed microstructure in the absence of recrystallization that defines a fibrous structure as the presence of the dispersoids impedes recrystallization of the deformed microstructure. For example,
The extruded article can be a vehicle component or an architectural component, as non-limiting examples. Non-limiting examples of vehicles that have components suitable to be produced with 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 current technology, the extruded article is an automobile part selected from the group consisting of a beam, a bumper, a floor pan, a battery enclosure, a wheel, a rocker, a control arm, a rail, a reinforcement panel, a step, a subframe member, a pillar, and a strut. Therefore, the current technology also provides an automobile 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 when pulled along an extrusion direction during tensile testing, an elongation to fracture of greater than or equal to about 8%, and a bending angle at maximum load of greater than or equal to about 100/√{square root over (t)}° based on the VDA238-100 bending test (sample size of 60 mm×60mm×t mm; punch radius of 0.4 mm; bending line perpendicular to the extrusion direction).
With reference to
With reference to
The method 50 then comprises heating the log billet 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 a heated log billet 41. The heating can be performed, for example, by heating the log billet 41 in a furnace.
After the heating, the method 50 comprises extruding the heated log billet 41 through a die to form a heated extruded article. The die comprises a slit that matches a cross-sectional geometry of the article being made. As such, the heated extruded article has a cross-sectional geometry defined by the die. The extruding is performed by pushing the alloy composition through the die with a ram at a ram 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 comprises quenching the heated extruded article to form the extruded article 52. The quenching is performed at a rate fast enough to avoid formation of undesirable precipitates, but not too fast that cracks or distortions are generated. Therefore, the quenching comprises lowering 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. The quenching is performed by any method that is capable of cooling at the above rates, such as by contacting the heated extruded part with water or cold water mist.
The method then optionally comprises aging the extruded article 52. The aging comprises heating the 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. to less than or equal to about 200° C., or greater than or equal to about 175 ° C. to less than or equal to about 185° C., such as at a temperature of 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., about 240° C., about 245° C., or about 250° C. The aging is performed 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 for 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 subsequently quenched.
In various aspects of the current technology, the method 50 also includes at least one of prior to the aging, stretching the extruded article 52 to improve the straightness of the extruded article 52; prior to or after the aging, discarding a portion from each end of the extruded article 52 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 (for example, it is envisioned that a plurality of objects can be cut to form a length of the extruded article 52); etching the extruded article 52; anodizing the extruded article 52; or further processing the extruded article 52, such as by bending or denting into a desired shape.
Forming the extruded article 52 results in a reduction of at least about 50%, at least about 70%, or at least about 90% of CO2 equivalents relative to a corresponding method performed with a primary Al alloy and without post-consumer Al scrap. In some aspects, the method generates about 10 tons, about 5 tons, or about 3 tons CO2 emission per 1 ton of the alloy composition extruded.
The foregoing description of the embodiments has been provided 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 specifically shown or described. The same may also be varied 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.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202110606973.X | Jun 2021 | CN | national |
