WO2025259916A1

WO2025259916A1 - Aluminum alloy composition utilizing scrap metal, and methods thereof

Info

Publication number: WO2025259916A1
Application number: PCT/US2025/033415
Authority: WO
Inventors: Jason Robert STUCKI
Original assignee: Tesla Inc
Current assignee: Tesla Inc
Priority date: 2024-06-14
Filing date: 2025-06-12
Publication date: 2025-12-18
Anticipated expiration: 2026-12-14

Abstract

An aluminum alloy composition is described, wherein the alloy may be formed from high amounts of scrap metal and other alloy components. The aluminum alloy composition may further include a hard factor and/or advanced sludge factor to aid in producing alloys having specific yield strength and ductility. Processes for forming the alloy are also described. The process may further include adjusting the alloy composition based on the hard factor and/or advanced sludge factor.

Description

ALUMINUM ALLOY COMPOSITION UTILIZING SCRAP METAL, AND

METHODS THEREOF

INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS

[0001] Any and all applications for which a foreign or domestic priority claim is identified in the Application Data Sheet or PCT Request as filed with the present application are hereby incorporated by reference under 37 CFR 1.57, and Rules 4.18 and 20.6. This application claims the benefit of U.S. Provisional Application No. 63/660,408, filed on June 14, 2024, which is incorporated by reference herein in its entirety for all purposes.

BACKGROUND

Field

[0002] The present application relates to aluminum alloys. More specifically, the present application relates to aluminum alloys formed from high amounts of scrap metal for high-performance applications, including die casting of automobile parts.

Description of the Related Art

[0003] Commercial cast aluminum alloys for certain applications, for example, structural components of an electric vehicle, generally require both high strength and ductility. It is desirable to form these parts through a casting process, such that the parts may be cast quickly and reliably, such as through a high-pressure die casting process. After casting, suitable alloys should maintain their structural properties sufficiently for the necessary application. Typically, large amounts of high purity metals are used in order to form such aluminum alloys with the required performance. However, the use of high purity metals increases the costs of the aluminum alloy in addition to causing supply chain bottlenecks.

SUMMARY

[0004] For purposes of summarizing the disclosure and the advantages achieved over the prior art, certain objects and advantages of the disclosure are described herein. Not all such objects or advantages may be achieved in any particular embodiment. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein.

[0005] All of these embodiments are intended to be within the scope of the invention herein disclosed. These and other embodiments will become readily apparent to those skilled in the art from the following detailed description of the preferred embodiments having reference to the attached figures, the invention not being limited to any particular preferred embodiment s) disclosed.

[0006] In one aspect, a process for preparing an alloy is described. The process includes: providing an initial alloy composition including an aluminum source, wherein at least 30 wt.% of the aluminum source includes scrap aluminum, melting the initial alloy composition to form an initial melted alloy, measuring at least one of a hard factor, an advanced sludge factor, or a combination thereof of the initial alloy composition, combining the initial melted alloy with a performance improving additive to form an adjusted melted alloy, wherein the adjusted melted alloy including an adjusted alloy composition includes, in wt.%: Si: about 6.5-8.5; Mn: about 0.25-0.7; Mg: about 0.25-0.5; Fe: at most about 0.6; Cu: at most about 0.3; Zn: at most about 0.35; Ti: at most about 0.1 ; each incidental impurity: at most about 0.1 ; total incidental impurities: at most about 0.3; and Al: remainder; wherein the adjusted alloy composition further includes: a hard factor of about 1-3.5; an a- Al volume fraction of about 85-99%; AlFeSi phases of at most about 6-0.05 wt.%; a yield strength of about 110-190 MPa; a bend angle of about 15-32°; and an advanced sludge factor of about 0.4-1.8; and cooling the adjusted melted alloy to form an as-cast alloy.

[0007] In another aspect, an alloy composition is described. The alloy composition includes, in wt.%: Si: about 6.5-8.5; Mn: about 0.25-0.7; Mg: about 0.25-0.5; and Al: remainder, wherein the alloy composition comprises a hard factor of about 1.1-2.

[0008] In some embodiments, the composition further includes, in wt.%: Fe: at most about 0.6; Cu: at most about 0.3; and Zn: at most about 0.35. In some embodiments, the composition further includes, in wt.%: Ti: at most about 0.1. In some embodiments, the composition further includes, in wt.%: Fe: at least about 0.25; Cu: at least about 0.03; and Zn: at least about 0.03. In some embodiments, the composition further includes, in wt.%: each incidental impurity: at most about 0.1; and total incidental impurities: at most about 0.3. In some embodiments, the alloy composition includes a hard factor of about 1.1-3.5. In some embodiments, the alloy composition includes an advanced sludge factor of about 0.4-1.8. In some embodiments, the alloy composition includes an a- Al volume fraction of about 85-99%. In some embodiments, the alloy composition includes AlFeSi phases of at most about 6-0.05 wt.%. In some embodiments, the alloy comprises a yield strength of about 110-170 MPa. In some embodiments, the alloy comprises a bend angle of about 15-27°.

[0009] In another aspect, a process for preparing an alloy is described. The process includes: providing alloy components comprising an aluminum source, wherein the aluminum source comprises a scrap aluminum source and wherein the alloy components comprise the scrap aluminum source in at least 35 wt.%; melting the alloy components to form a melted alloy; and cooling the melted alloy to form an as-cast alloy.

[0010] In another aspect, a process for preparing an alloy is described. The process includes: providing an initial alloy composition including an aluminum source, wherein at least 30 wt.% of the aluminum source includes scrap aluminum, melting the initial alloy composition to form an initial melted alloy, measuring at least one of a hard factor, an advanced sludge factor, or a combination thereof of the initial alloy composition, combining the initial melted alloy with a performance improving additive to form an adjusted melted alloy, and cooling the adjusted melted alloy to form an as-cast alloy.

[0011] In some embodiments, the process further includes die-casting the melted alloy. In some embodiments, die-casting is high-pressure die-casting (HPDC). In some embodiments, the adjusted melted alloy includes a casting flow length under HPDC conditions of about 1-5 m. In some embodiments, the aluminum source includes virgin aluminum of about 0.1-90 wt.%. In some embodiments, combining the initial melted alloy with the performance improving additive selected from the group consisting of Mn, Mo, Cr, Ni, Mg, V, Sr, Si, and combinations thereof. In some embodiments, the adjusted melted alloy is substantially free of virgin aluminum. In some embodiments, measuring the hard factor may include calculating a sum of Mg wt.%, Cu wt.%, Zn wt.%, or combinations thereof. In some embodiments, measuring the advanced sludge factor may include calculating a sum of Fe wt.%, Mn wt.%, V wt.%, Cr wt.%, Co wt.%, Ni wt.%, Mo wt.%, or combinations thereof. In some embodiments, the process further includes injection molding the adjusted melted alloy prior to cooling. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIG. 1 A is a bar chart showing various commercial aluminum alloys formed with magnesium and copper elements by weight percent (wt.%).

[0013] FIG. IB is a bar chart showing various commercial aluminum alloys formed with silicon and iron elements by wt.%.

[0014] FIG. 2 shows a scanning electron microscopy (SEM) image of an alloy casting surface with pyramidal AlFeSi(Mn) growths, according to some embodiments.

[0015] FIG. 3 shows a yield strength vs. bend angle graph of aluminum alloys, according to some embodiments, compared to control aluminum alloys.

[0016] FIG. 4 is an image which shows a microstructure of an aluminum alloy formed using a high-pressure die cast process, according to some embodiments.

DETAILED DESCRIPTION

[0017] The present disclosure may be understood by reference to the following detailed description. It is noted that, for purposes of illustrative clarity, certain elements in various drawings may not be drawn to scale, may be represented schematically or conceptually, or otherwise may not correspond exactly to certain physical configurations of embodiments.

[0018] Embodiments of the disclosure relate to casting aluminum alloys with both sufficiently high yield strengths and ductilities that can be formed using high amounts of scrap aluminum metals (i.e., “scrap” grade aluminum (e.g., recycled aluminum)). Although some elemental impurities of scrap aluminum may lead to hindering the performance of the final aluminum alloy (i.e., performance detracting elements), performance improving additives may be utilized to counteract these negative effects of the performance detracting elements. In some embodiments, such aluminum alloys may be characterized by Hard Factor (HF) and/or Sludge Factor (SF) (e.g., advanced sludge factor) as described herein.

[0019] FIGS. 1A and IB are bar graphs showing various commercial aluminum alloys formed with elements by weight percent. As shown in FIG. 1A, the aluminum scrap market includes uses of Mg and Cu. In FIG. IB, the aluminum scrap market also includes uses of Si and Fe. [0020] In some embodiments, performance detracting elements include Fe, Cu, Zn, Mo, Cr, Ni, Ti and Sn. In some embodiments, performance improving additives include Mn, Mg, V, Sr, Si, Mo, Cr and/or Ni. For example, iron impurities may embrittle an aluminum alloy through the formation of AlFeSi phases, and performance improving additives may prevent or reduce the formation of such phases. FIG. 2 shows an SEM image of an alloy casting surface with pyramidal AlFeSi(Mn) growths. As shown in FIG. 2, the presence of Fe in the alloy casting surface results in formation of AlFeSi(Mn) phases, allowing for improved durability and tool life but with decreased ductility.

[0021] As such, in some embodiments, the aluminum alloy formed may have a high aluminum scrap market compatibility and robust performance (e.g., yield strength and/or ductility) when utilized in die casting (e.g., high-pressure die casting (HPDC)) processes.

Aluminum Alloy Compositions

[0022] The aluminum alloys are described herein by the weight percent (wt.%) of the total elements and particles within the alloy, as well as specific properties of the alloys. It will be understood that the remaining composition of any alloy described herein is aluminum and, optionally, incidental impurities. It will also be understood that the wt.% values of any of the elements may be applied to any alloy composition disclosed herein (e.g., an initial alloy composition and/or an adjusted alloy composition).

[0023] In some embodiments, the aluminum alloy composition comprises silicon (Si) in an amount of, of about, of at least, of at least about, of at most, or of at most about, 15 wt.%, 13 wt.%, 12 wt.%, 11 wt.%, 10 wt.%, 9 wt.%, 8.5 wt.%, 8 wt.%, 7 wt.%, 6.5 wt.%, 6 wt.%, 5 wt.% or 3 wt.%, or any range of values therebetween. In some embodiments, the aluminum alloy composition comprises manganese (Mn) in an amount of, of about, of at least, of at least about, of at most, or of at most about, 1.5 wt.%, 1.2 wt.%, 1 wt.%, 0.9 wt.%, 0.8 wt.%, 0.7 wt.%, 0.6 wt.%, 0.5 wt.%, 0.45 wt.%, 0.4 wt.%, 0.35 wt.%, 0.3 wt.%, 0.25 wt.%, 0.2 wt.%, 0.15 wt.%, 0.1 wt.% or 0.05 wt.%, or any range of values therebetween. In some embodiments, the aluminum alloy composition comprises magnesium (Mg) in an amount of, of about, of at least, of at least about, of at most, or of at most about, 1 wt.%, 0.9 wt.%, 0.8 wt.%, 0.7 wt.%, 0.6 wt.%, 0.5 wt.%, 0.45 wt.%, 0.4 wt.%, 0.35 wt.%, 0.3 wt.%, 0.25 wt.%, 0.2 wt.%, 0.15 wt.%, 0.1 wt.% or 0.05 wt.%, or any range of values therebetween. [0024] In some embodiments, the aluminum alloy composition comprises vanadium (V) in an amount of, of about, of at least, of at least about, of at most, or of at most about, 1 wt.%, 0.9 wt.%, 0.8 wt.%, 0.7 wt.%, 0.6 wt.%, 0.5 wt.%, 0.45 wt.%, 0.4 wt.%, 0.35 wt.%, 0.3 wt.%, 0.25 wt.%, 0.2 wt.%, 0.15 wt.%, 0.1 wt.% or 0.05 wt.%, or any range of values therebetween. In some embodiments, the aluminum alloy composition comprises molybdenum (Mo) in an amount of, of about, of at least, of at least about, of at most, or of at most about, 1 wt.%, 0.9 wt.%, 0.8 wt.%, 0.7 wt.%, 0.6 wt.%, 0.5 wt.%, 0.45 wt.%, 0.4 wt.%, 0.35 wt.%, 0.3 wt.%, 0.25 wt.%, 0.2 wt.%, 0.15 wt.%, 0.1 wt.% or 0.05 wt.%, or any range of values therebetween. In some embodiments, the aluminum alloy composition comprises chromium (Cr) in an amount of, of about, of at least, of at least about, of at most, or of at most about, 1 wt.%, 0.9 wt.%, 0.8 wt.%, 0.7 wt.%, 0.6 wt.%, 0.5 wt.%, 0.45 wt.%, 0.4 wt.%, 0.35 wt.%, 0.3 wt.%, 0.25 wt.%, 0.2 wt.%, 0.15 wt.%, 0.1 wt.% or 0.05 wt.%, or any range of values therebetween. In some embodiments, the aluminum alloy composition comprises nickel (Ni) in an amount of, of about, of at least, of at least about, of at most, or of at most about, 1 wt.%, 0.9 wt.%, 0.8 wt.%, 0.7 wt.%, 0.6 wt.%, 0.5 wt.%, 0.45 wt.%, 0.4 wt.%, 0.35 wt.%, 0.3 wt.%, 0.25 wt.%, 0.2 wt.%, 0.15 wt.%, 0.1 wt.% or 0.05 wt.%, or any range of values therebetween.

[0025] In some embodiments, the aluminum alloy composition comprises iron (Fe) in an amount of, of about, of at least, of at least about, of at most, or of at most about, 1 wt.%, 0.9 wt.%, 0.8 wt.%, 0.7 wt.%, 0.6 wt.%, 0.5 wt.%, 0.4 wt.%, 0.35 wt.%, 0.3 wt.%, 0.26 wt.%, 0.25 wt.%, 0.2 wt.%, 0.15 wt.%, 0.1 wt.%, 0.05 wt.% or 0.01 wt.%, or any range of values therebetween. In some embodiments, the aluminum alloy composition comprises copper (Cu) in an amount of, of about, of at least, of at least about, of at most, or of at most about, 1 wt.%, 0.9 wt.%, 0.8 wt.%, 0.7 wt.%, 0.6 wt.%, 0.5 wt.%, 0.4 wt.%, 0.35 wt.%, 0.3 wt.%, 0.25 wt.%, 0.2 wt.%, 0.15 wt.%, 0.1 wt.%, 0.06 wt.%, 0.05 wt.%, 0.04 wt.%, 0.03 wt.%, 0.02 wt.% and 0.01 wt.%, or any range of values therebetween. In some embodiments, the aluminum alloy composition comprises zinc (Zn) in an amount of, of about, of at least, of at least about, of at most, or of at most about, 1 wt.%, 0.9 wt.%, 0.8 wt.%, 0.7 wt.%, 0.6 wt.%, 0.5 wt.%, 0.4 wt.%, 0.35 wt.%, 0.3 wt.%, 0.25 wt.%, 0.2 wt.%, 0.15 wt.%, 0.1 wt.%, 0.06 wt.%, 0.05 wt.%, 0.04 wt.%, 0.03 wt.%, 0.02 wt.% and 0.01 wt.%, or any range of values therebetween.

[0026] In some embodiments, the aluminum alloy composition comprises titanium (Ti) in an amount of, of about, of at least, of at least about, of at most, or of at most about, 0.3 wt.%, 0.2 wt.%, 0.15 wt.%, 0.14 wt.%, 0.13 wt.%, 0.12 wt.%, 0.1 wt.%, 0.08 wt.%, 0.07 wt.%, 0.06 wt.%, 0.05 wt.%, 0.04 wt.%, 0.03 wt.%, 0.02 wt.%, 0.01 wt.% or 0.005 wt.%, or any range of values therebetween.

[0027] In some embodiments, the aluminum alloy composition comprises strontium (Sr) in an amount of, of about, of at least, of at least about, of at most, or of at most about, 0.2 wt.%, 0.18 wt.%, 0.16 wt.%, 0.14 wt.%, 0.12 wt.%, 0.1 wt.%, 0.09 wt.%, 0.08 wt.%, 0.07 wt.%, 0.06 wt.%, 0.05 wt.%, 0.04 wt.%, 0.03 wt.%, 0.02 wt.%, 0.01 wt.% or 0.005 wt.%, or any range of values therebetween.

[0028] In some embodiments, the aluminum alloy composition comprises tin (Sn) in an amount of, of about, of at least, of at least about, of at most, or of at most about, 0.2 wt.%, 0.18 wt.%, 0.16 wt.%, 0.14 wt.%, 0.12 wt.%, 0.1 wt.%, 0.09 wt.%, 0.08 wt.%, 0.07 wt.%, 0.06 wt.%, 0.05 wt.%, 0.04 wt.%, 0.03 wt.%, 0.02 wt.%, 0.01 wt.% or 0.005 wt.%, or any range of values therebetween.

[0029] In some embodiments, the a-Al volume fraction of an alloy is, is about, is at most, is at most about, is at least, or is at least about, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99%, or any range of values therebetween. In some embodiments, the aluminum alloy composition comprises AlFeSi phases in, in about, in at most, in at most about, in at least, or in at least about, 6 wt.%, 5 wt.%, 4.5 wt.%, 4 wt.%, 3.7 wt.%, 3.5 wt.%, 3.4 wt.%, 3.2 wt.%, 3.1 wt.%, 3 wt.%, 2.9 wt.%, 2.8 wt.%, 2.7 wt.%, 2.6 wt.%, 2.5 wt.%, 2.4 wt.%, 2.2 wt.%, 2 wt.%, 1.8 wt.%, 1.5 wt.%, 1.2 wt.%, 1 wt.%, 0.9 wt.%, 0.8 wt.%, 0.7 wt.%, 0.6 wt.%, 0.5 wt.%, 0.45 wt.%, 0.4 wt.%, 0.35 wt.%, 0.3 wt.%, 0.25 wt.%, 0.2 wt.%, 0.15 wt.%, 0.1 wt.% or 0.05 wt.%, or any range of values therebetween.

[0030] Impurities may be present in the starting materials or introduced in one of the processing and/or manufacturing steps to create the aluminum alloy. Incidental impurities are compounds and/or elements that do not or do not substantially affect the material properties of the composition, such as yield strength and/or ductility. In some embodiments, the total incidental impurities are, are about, are at least, are at least about, are at most, or are at most about, 1 wt.%, 0.8 wt.%, 0.6 wt.%, 0.5 wt.%, 0.4 wt.%, 0.3 wt.%, 0.2 wt.%, 0.15 wt.%, 0.1 wt.%, 0.07 wt.%, 0.05 wt.%, 0.04 wt.%, 0.03 wt.%, 0.02 wt.%, 0.01 wt.% or 0.005 wt.%, or any range of values therebetween. In some embodiments, each elemental incidental impurity is, is about, is at least, is at least about, is at most, or is at most about, 0.5 wt.%, 0.4 wt.%, 0.3 wt.%, 0.2 wt.%, 0.1 wt.%, 0.07 wt.%, 0.05 wt.%, 0.04 wt.%, 0.03 wt.%, 0.02 wt.%, 0.01 wt.%, 0.005 wt.% or 0.001 wt.%, or any range of values therebetween.

[0031] In some embodiments, performance detracting elements may be present in varying amounts of scrap. In order to maximize scrap usage, fluctuations in performance detracting elements may be controlled by use of performance improving additives.

[0032] Hard Factor (HF) may be used as a compositional guide to determine aluminum alloys (e.g., HPDC products) with specific yield strength and ductility by controlling the use of performance improving additives. In aluminum alloys disclosed herein, Mg may act as a primary hardener with Cu and Zn as contributors. HF for an aluminum alloy may be adjusted by additions of Mg, Cu, and Zn, according to the empirical equation below.

Hard Factor HF) = (wt. % of Mg x 3) + (wt. % of Cu x 2) + (wt. % of Zn)

[0033] As such, the aluminum alloy (e.g., HPDC product) may be produced with a specific yield strength and ductility based on the HF. Generally and relatively, increasing HF increases yield strength and reduces ductility, while decreasing HF increases ductility and reduces yield strength. In some embodiments, adjusting (e.g., adjusting an amount of an element, adjusting wt.% of an element) a performance improving additive and/or a performance detracting element may impact HF. In some embodiments, adjusting one or more performance improving additives and/or one or more performance detracting elements may impact HF. In some embodiments, HF may be increased by adding (e.g., increasing an amount of an element, increasing wt.% of an element) a performance improving additive. In some embodiments, HF may be increased by adding magnesium (Mg). In some embodiments, HF may be increased by adding copper (Cu). In some embodiments, HF may be increased by adding zinc (Zn). In some embodiments, HF may be increased by adding Mg, Cu, Zn, and/or combinations thereof. In some embodiments, HF may be decreased by adding aluminum (e.g., scrap aluminum metals and/or virgin aluminum). In some embodiments, the alloy comprises a hard factor of, of about, of at least, or of at least about, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1, 1.05, 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45, 1.5, 1.55, 1.6, 1.65, 1.7, 1.75 or 1.8, or any range of values therebetween.

[0034] In some conventional aluminum alloys (e.g., Al-Si based alloys), Fe, Mn and Cr are known to create high temperature stable phases that may precipitate out from an alloy melt in a furnace (e.g., sludge formation). A Sludge Factor (SF) formulation and a melt temperature may be commonly used to reduce likelihood of precipitations in the alloy holding furnace. However, such SF formulations may include additional elements including V, Co, Ni, and Mo, according to the Advanced SF (ASF) empirical equation below. It is to be understood that the ASF equation below may differ from the typical SF equation known in the art.

Advanced Sludge Factor ASF) = (wt. % of Fe) + (wt. % of Mn X 2) + (<p x 3) Where: <p = £ wt. % (V, Cr, Co, Ni, Mo)

[0035] The Advanced SF formulation may be used to reduce the risk of sludge formation within the melt furnace and to predict a volume fraction of AlFeSi phases that may be detrimental to ductility in a cast aluminum alloy product (e.g., high ASF reduces ductility while low ASF reduces castability). Conversely, the Advanced SF formulation may be used to ensure that the elemental content does not drift too low of a threshold which may negatively impact castability such as die solder and/or erosion. In some embodiments, adjusting (e.g., adjusting an amount of an element, adjusting wt.% of an element) a performance improving additive and/or a performance detracting element may impact ASF. In some embodiments, adjusting one or more performance improving additives and/or one or more performance detracting elements may impact ASF. In some embodiments, ASF may be increased by adding (e.g., increasing an amount of an element, increasing wt.% of an element) a performance improving additive. In some embodiments, ASF may be increased by adding manganese (Mn). In some embodiments, ASF may be increased by adding iron (Fe). In some embodiments, ASF may be increased by adding performance improving additives (e.g., V, Cr, Co, Ni, Mo). In some embodiments, ASF may be increased by adding Mn, Fe, V, Cr, Co, Ni, Mo, and/or combinations thereof. In some embodiments, ASF may be decreased by adding aluminum (e.g., scrap aluminum metals and/or virgin aluminum). In some embodiments, the alloy comprises an advanced sludge factor of, of about, of at least, or of at least about, 1, 1.05, 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45, 1.5, 1.55, 1.6, 1.65, 1.7, 1.75, 1.8, 1.85, 1.9, 1.95, 2, 2.05, 2.1, 2.15, 2.2, 2.25, 2.3, 2.35, 2.4, 2.45, 2.5, 2.55, 2.6, 2.65, 2.7, 2.75, 2.8, 2.85, 2.9, 2.95, 3, 3.05, 3.1, 3.15, 3.2, 3.25, 3.3, 3.35, 3.4, 3.45 or 3.5, or any range of values therebetween.

[0036] In some embodiments, a range of wt.% values may be listed for a given element. A nominal value is considered to be an average of an upper limit and lower limit of the wt.% values listed. In some embodiments where a lower limit is not provided, a nominal value may not be calculated. In some embodiments, the use of HF and advanced SF disclosed herein may indicate that performance improving additives (e.g., Mg and/or Mn) may not have nominal values based on an upper and lower limit. Therefore, for aluminum alloys disclosed herein, Mn’s nominal value may be a function of Fe, Cr, V, Mo, Co and Ni (i.e., sum of the elements’ wt.%). In some embodiments, Mg’s nominal value may be a function of Cu and Zn wt.%. Such nominal values may help design efficient recycling processes and secondary alloy production since the performance detracting elements (e.g., Cu, Zn, Fe, Cr, V, Mo, Co and Ni) may be acquired from various aluminum scrap streams.

Alloy Yield Strength

[0037] In some embodiments, the yield strength of the alloy is, is about, is at least, or is at least about, 105 MPa, 110 MPa, 115 MPa, 120 MPa, 125 MPa, 130 MPa, 135 MPa, 140 MPa, 145 MPa, 150 MPa, 155 MPa, 160 MPa, 165 MPa, 170 MPa, 180 MPa, 190 MPa or 200 MPa, or any range of values therebetween.

Alloy Ductility

[0038] The ductility of metal alloy should also be considered such that the parts are reproducibly manufacturable by using a casting process. Ductility of an alloy may be measured by the bend angle and/or the elongation of the alloy. In some embodiments, the bend angle is measured using the VDA 238-100 evaluation standards. In some embodiments, the bend angle is measured at a 3 mm section thickness. In some embodiments, the bend angle of an alloy is, is about, is at least, or is at least about, 10°, 12°, 13°, 14°, 15°, 16°, 17°, 18°, 19°, 20°, 21°, 22°, 23°, 24°, 25°, 26°, 27°, 28°, 29°, 30°, 31° or 32° or any range of values therebetween.

Manufacturing and Processing Methods

[0039] In some embodiments, a melt for an alloy can be prepared by heating the alloy above the melting temperature of the alloy components. As the melt is cast and cooled to room temperature, the alloys may go through cooling at various rates. The processing conditions can create larger or smaller grain sizes, increase or decrease the size and number of precipitates, and help minimize as-cast segregation. [0040] In some embodiments, a process for preparing an alloy may include providing alloy components (e.g., initial alloy composition, adjusted alloy composition), melting the alloy components to form a melted alloy (e.g., initial melted alloy, adjusted melted alloy) and cooling the melted alloy to form an as-cast alloy. In some embodiments, the initial alloy composition and/or the adjusted alloy composition includes the same composition as a composition of the as-cast alloy. In some embodiments, the process may further include melting the alloy components (e.g., an initial alloy composition) to form an initial melted alloy, and adding a performance improving additive to the initial melted alloy to form an adjusted melted alloy with a different alloy composition compared to the initial alloy composition (e.g., adjusted alloy composition). In some embodiments, the process may further include measuring at least one of a hard factor, an advanced sludge factor, or a combination thereof of the initial melted alloy, initial alloy composition, adjusted melted alloy, and/or adjusted alloy composition. In some embodiments, the process may not include measuring the at least one of a hard factor, an advanced sludge factor, or a combination thereof (e.g., when the initially alloy composition is already known and/or provided). In some embodiments, measuring may include measuring elemental compositions of the alloy components. In some embodiments, measuring may include one or more measurements of the elemental compositions. In some embodiments, the process may include measuring and/or calculating the at least one of a hard factor, an advanced sludge factor, or a combination thereof based on the measured compositions of the alloy components. In some embodiments, measuring the hard factor may include calculating a sum of Mg wt.%, Cu wt.%, Zn wt.%, or combinations thereof. In some embodiments, measuring the advanced sludge factor may include calculating a sum of Fe wt.%, Mn wt.%, V wt.%, Cr wt.%, Co wt.%, Ni wt.%, Mo wt.%, or combinations thereof. In some embodiments, the process may include one or more measuring steps or measuring at least one of the hard factor, the advanced sludge factor, or the combination thereof more than once. In some embodiments, the process may further include combining the initial melted alloy with a performance improving additive. In some embodiments, the process may further include combining the initial melted alloy with a performance improving additive selected from the group consisting of Mn, Mo, Cr, Ni, Mg, V, Sr, Si, and combinations thereof. In some embodiments, the process may further include adjusting a wt.% of the performance improving additive based on the at least one of the hard factor, the advanced sludge factor, or the combination thereof. In some embodiments, the melted alloy (e.g., initial melted alloy, adjusted melted alloy) may include one or more performance improving additives. In some embodiments, the process may include one or more adjusting steps or adjusting the wt.% of any of the elemental compositions more than once.

[0041] In some embodiments, the process may include melting the alloy components (e.g., an initial alloy composition) to form a first melted alloy with an initial alloy composition. In some embodiments, the process may further include measuring at least one of a hard factor, a sludge factor (e.g., an advanced sludge factor), or a combination thereof of the first melted alloy. In embodiments where measuring the hard factor and/or the advanced sludge factor does not satisfy values of a determined hard factor and/or a determined advanced sludge factor, the process may further include adjusting the initial alloy composition based on the determined hard factor and/or the determined advanced sludge factor by combining the first melted alloy with a performance improving additive to form a second melted alloy with an adjusted alloy composition. In some embodiments, adjusting the initial alloy composition may include adjusting a wt.% of the performance improving additive based on the at least one of the determined hard factor and/or the determined advanced sludge factor. The wt.% values of the performance improving additive disclosed herein may be applied to any alloy composition (e.g., an initial alloy composition and/or the adjusted alloy composition).

[0042] In some embodiments, the melt of the alloy (e.g., initial melted alloy, adjusted melted alloy) is formed from alloy components (e.g., initial alloy composition, adjusted alloy composition) that include an aluminum source. In some embodiments, the melt of the alloy is formed from alloy components that are free of or substantially free of an aluminum source (e.g., virgin aluminum). In some embodiments, the aluminum source includes scrap aluminum metal (i.e., recycled aluminum metal), which may have increased impurity levels relative to virgin high purity sources of aluminum metal. In some embodiments, the aluminum source includes scrap aluminum in, in about, in at least, in at least about, in at most, or in at most about, 1 wt.%, 2 wt.%, 3 wt.%, 4 wt.%, 5 wt.%, 6 wt.%, 8 wt.%, 10 wt.%, 15 wt.%, 20 wt.%, 25 wt.%, 30 wt.%, 35 wt.%, 40 wt.%, 45 wt.%, 50 wt.%, 55 wt.%, 60 wt.%, 65 wt.%, 70 wt.%, 75 wt.%, 80 wt.%, 85 wt.%, 90 wt.%, 92 wt.%, 95 wt.%, 98 wt.%, 99 wt.% or 100 wt.%, or any range of values therebetween. In some embodiments, the aluminum source includes virgin (i.e., primary) aluminum in, in about, in at least, in at least about, in at most, or in at most about, 0.1 wt.%, 0.5 wt.%, 1 wt.%, 2 wt.%, 3 wt.%, 4 wt.%, 5 wt.%, 6 wt.%, 8 wt.%, 10 wt.%, 15 wt.%, 20 wt.%, 25 wt.%, 30 wt.%, 35 wt.%, 40 wt.%, 45 wt.%, 50 wt.%, 55 wt.%, 60 wt.%, 65 wt.%, 70 wt.%, 75 wt.%, 80 wt.%, 85 wt.% or 90 wt.%, or any range of values therebetween. In some embodiments, the elemental composition of the scrap aluminum is measured. In some embodiments, a performance improving additive (e.g., Mn, V, Mo, Cr and/or Ni; Mn, Mg, V, Sr and/or Si; Mn, Mo, Cr, Ni, Mg, V, Sr and/or Si) is added to the melt in order to adjust or compensate for the performance detracting elements (e.g., Fe, Cu and/or Zn; Fe, Cu, Zn, Mo, Cr, Ni, Ti, and/or Sn) measured in the scrap aluminum utilized. In some embodiments, the elemental composition of the scrap aluminum is not adjusted prior to utilization within the melt.

[0043] In some embodiments, the aluminum alloy must provide sufficient flowability and resistance to hot tearing and shrinkage cracking when die cast (e.g., high- pressure die cast (HPDC)). Unless specified otherwise, flow lengths described herein are under HPDC conditions. In a metal casting process, the metal alloy must have sufficient flowability to flow into and fill all intricacies of the mold. In molds with narrow and/or long mold channels, a sufficiently high flowability of the alloy is required to fill the mold.

[0044] In some embodiments, the alloy is die-cast. In some embodiments, the alloy is high-pressure die-cast (HPDC). In certain embodiments, the aluminum alloy is cast without further processing. In some embodiments, the as-cast aluminum alloy is not further processed through heat treatment, and maintains the yield strength and ductility as mentioned above. In other embodiments, the as-cast aluminum alloy is further processed. In some embodiments, further processing methods include heat treating, aging, solution treating and surface finishing.

[0045] Hot tearing and shrinkage cracking are common and catastrophic defects observed when casting alloys, including aluminum alloys. Without being able to prevent hot tearing in alloy, reliable and reproducible parts cannot be created. Hot tearing is the formation of an irreversible crack while the cast part is still in the semisolid casting. Although hot tearing is often associated with the casting process itself — linked to the creation of thermal stresses during the shrinkage of the melt flow during solidification, the underlying thermodynamics and microstructure of the alloy play a part.

[0046] In some embodiments, the alloy has a casting flow length under HPDC conditions of, of about, of at least, or of at least about, 1 m, 1.1 m, 1.2 m, 1.3 m, 1.4 m, 1.5 m, 1.6 m, 1.7 m, 1.8 m, 1.9 m, 2 m, 2.2 m, 2.5 m, 3 m or 5 m, or any range of values therebetween. In some embodiments, the alloy does not, or does not substantially, develop hot tears and/or shrinkage cracks throughout the casting flow length.

[0047] In certain embodiments, after the aluminum-alloy melt has been formed, it may be cast into a die to form a high-performance product or part. In some embodiments, a HDPC product or high-performance product can be part of an automobile, such as parts of chassis and/or other crash components (e.g., crash critical structure components). In some embodiments, the HDPC product is used as a structural body casting (e.g., underbody, subframe, outer body) and/or as an energy absorbing structure (e.g., crash rails).

[0048] In some embodiments, after the aluminum-alloy melt has been formed, it may be injection molded. The alloy melt may be subjected to an injection molding process such that the alloy melt is cooled in a molding apparatus to form a cast metal product or an as- cast alloy.

[0049] In some embodiments, the aluminum-alloy melt may be subjected to an additive manufacturing process to form an alloy product. In some embodiments, the additive manufacturing process includes using 3-D (3 -dimensional) printing processes such as laser melting, laser sintering jetting, and combinations thereof.

EXAMPLES

[0050] Table 1 provides an example specification elemental composition of an aluminum alloy utilizing high amounts of scrap aluminum metal (i.e., “Alloy A” and “Alloy B”), compared to 365. X and 374.X aluminum alloys per the Aluminum Association “Pink Sheets.” Table 2 shows the maximum amount of various types of scrap aluminum that each of the Alloy A, 365. X and 374. X aluminum alloys can utilize in a melt to create that alloy without passing grade specification, and which elements have reached their limit when the maximum amount of the listed scrap type is used. Each scrap type is considered individually and not in combination with other types of scrap aluminum. Table 1

Table 2

[0051] FIG. 3 shows the yield strengths and bend angles of the Alloy A, 365.X and 374.X aluminum alloys, where mechanical test coupons were excised from structural HPDC parts. ASTM Tensile E8 subsize tensile coupons were tested, and bend coupons 60 mm x 30mm were tested per VDA-238-100. The Alloy A melt was produced from a market scrap aluminum blend using a rotary furnace, and included 30 wt.% wheels, 30 wt.% polished twitch, 15 wt.% aluminum radiators, 15 wt.% extrusions, 10 wt.% EC chops. The Fe, Cu, and Zn contents of the Alloy A remained below the specification shown in Table 1, as well as the others (each) and others (total). FIG. 3 shows that Alloy A allows for increased scrap aluminum input, while but maintaining structural performance. As such, Alloy A (or alternatively, Alloy B) may be used for crash critical structural components.

[0052] Table 3 provides elemental compositions of aluminum alloys, including Alloy A and Alloy B, utilizing high amounts of scrap aluminum metal.

Table 3

[0053] For example, Alloy 11 in Table 3 may produce HPDC castings having a yield strength (with a 0.2% offset) of 145 MPa with limited ductility. In another example, Alloy 1 with a HF of 1.11 may produce HPDC castings having a yield strength (with a 0.2% offset) of 110 MPa with higher ductility compared to Alloy 11.

[0054] FIG. 4 shows a microstructure of Alloy 11 from Table 3. The microstructure of the alloy shows an aluminum substrate 510 with globular formulations of AlFeSi 520, Mg2Si 530 as a primary hardener, and a eutectic phase 540 formed from a combination of the aluminum substrate 510 and silicon.

[0055] While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the disclosure. Indeed, the novel methods and systems described herein may be embodied in a variety of other forms. Furthermore, various omissions, substitutions and changes in the systems and methods described herein may be made without departing from the spirit of the disclosure. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the disclosure.

[0056] Features, materials, characteristics, or groups described in conjunction with a particular aspect, embodiment, or example are to be understood to be applicable to any other aspect, embodiment or example described in this section or elsewhere in this specification unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. The protection is not restricted to the details of any foregoing embodiments. The protection extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

[0057] Furthermore, certain features that are described in this disclosure in the context of separate implementations can also be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single implementation can also be implemented in multiple implementations separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations, one or more features from a claimed combination can, in some cases, be excised from the combination, and the combination may be claimed as a subcombination or variation of a subcombination.

[0058] Moreover, while operations may be depicted in the drawings or described in the specification in a particular order, such operations need not be performed in the particular order shown or in sequential order, or that all operations be performed, to achieve desirable results. Other operations that are not depicted or described can be incorporated in the example methods and processes. For example, one or more additional operations can be performed before, after, simultaneously, or between any of the described operations. Further, the operations may be rearranged or reordered in other implementations. Those skilled in the art will appreciate that in some embodiments, the actual steps taken in the processes illustrated and/or disclosed may differ from those shown in the figures. Depending on the embodiment, certain of the steps described above may be removed, others may be added. Furthermore, the features and attributes of the specific embodiments disclosed above may be combined in different ways to form additional embodiments, all of which fall within the scope of the present disclosure. Also, the separation of various system components in the implementations described above should not be understood as requiring such separation in all implementations, and it should be understood that the described components and systems can generally be integrated together in a single product or packaged into multiple products. For example, any of the components for an energy storage system described herein can be provided separately, or integrated together (e.g., packaged together, or attached together) to form an energy storage system.

[0059] For purposes of this disclosure, certain aspects, advantages, and novel features are described herein. Not necessarily all such advantages may be achieved in accordance with any particular embodiment. Thus, for example, those skilled in the art will recognize that the disclosure may be embodied or carried out in a manner that achieves one advantage or a group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein.

[0060] Conditional language, such as “can,” “could,” “might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements, and/or steps. Thus, such conditional language is not generally intended to imply that features, elements, and/or steps are in any way required for one or more embodiments or that one or more embodiments necessarily include logic for deciding, with or without user input or prompting, whether these features, elements, and/or steps are included or are to be performed in any particular embodiment. [0061] Conjunctive language such as the phrase “at least one of X, Y, and Z,” unless specifically stated otherwise, is otherwise understood with the context as used in general to convey that an item, term, etc. may be either X, Y, or Z. Thus, such conjunctive language is not generally intended to imply that certain embodiments require the presence of at least one of X, at least one of Y, and at least one of Z.

[0062] Language of degree used herein, such as the terms “approximately,” “about,” “generally,” and “substantially” as used herein represent a value, amount, or characteristic close to the stated value, amount, or characteristic that still performs a desired function or achieves a desired result. For example, the terms “approximately,” “about,” “generally,” and “substantially” may refer to an amount that is within less than 10% of, within less than 5% of, within less than 1% of, within less than 0.1% of, and within less than 0.01% of the stated amount, depending on the desired function or desired result.

[0063] The scope of the present disclosure is not intended to be limited by the specific disclosures of preferred embodiments in this section or elsewhere in this specification, and may be defined by claims as presented in this section or elsewhere in this specification or as presented in the future. The language of the claims is to be interpreted broadly based on the language employed in the claims and not limited to the examples described in the present specification or during the prosecution of the application, which examples are to be construed as non-exclusive.

[0064] The headings provided herein, if any, are for convenience only and do not necessarily affect the scope or meaning of the devices and methods disclosed herein.

Claims

WHAT IS CLAIMED IS:

1. A process for preparing an alloy composition, comprising: providing an initial alloy composition comprising an aluminum source, wherein at least 30 wt.% of the aluminum source comprises scrap aluminum; melting the initial alloy composition to form an initial melted alloy; measuring at least one of a hard factor, an advanced sludge factor, and a combination thereof of the initial alloy composition; combining the initial melted alloy with a performance improving additive selected from the group consisting of Mn, Mo, Cr, Ni, Mg, V, Sr, Si, and combinations thereof to form an adjusted melted alloy, wherein the adjusted melted alloy comprising an adjusted alloy composition comprises, in wt.%:

Si: about 6.5-8.5;

Mn: about 0.25-0.7;

Mg: about 0.25-0.5;

Fe: at most about 0.6;

Cu: at most about 0.3;

Zn: at most about 0.35;

Ti: at most about 0.1 ; each incidental impurity: at most about 0.1; total incidental impurities: at most about 0.3; and

Al: remainder; wherein the adjusted alloy composition further comprises: a hard factor of about 1-3.5; an a-Al volume fraction of about 85-99%;

AlFeSi phases of at most about 6-0.05 wt.%; a yield strength of about 110-190 MPa; a bend angle of about 15-32°; and an advanced sludge factor of about 0.4-1.8; and cooling the adjusted melted alloy to form an as-cast alloy.

2. An alloy composition, comprising, in wt.%:

Si: about 6.5-8.5; Mn: about 0.25-0.7;

Mg: about 0.25-0.5; and

Al: remainder; wherein the alloy composition comprises a hard factor of about 1.1-2.

3. The alloy composition of Claim 2, further comprising, in wt.%:

Fe: at most about 0.6;

Cu: at most about 0.3; and

Zn: at most about 0.35.

4. The alloy composition of Claim 2 or 3, further comprising, in wt.%: Ti: at most about 0.1.

5. The alloy composition of any one of Claims 2-4, further comprising, in wt.%: Fe: at least about 0.25;

Cu: at least about 0.02; and

Zn: at least about 0.02.

6. The alloy composition of any one of Claims 2-5, further comprising, in wt.%: each incidental impurity: at most about 0.1; and total incidental impurities: at most about 0.3.

7. The alloy composition of any one of Claims 2-6, wherein the hard factor is about 1-3.5.

8. The alloy composition of any one of Claims 2-7, wherein the alloy composition comprises an advanced sludge factor of about 0.4-1.8.

9. The alloy composition of any one of Claims 2-8, wherein the alloy composition comprises an a- Al volume fraction of about 85-99%.

10. The alloy composition of any one of Claims 2-9, wherein the alloy composition comprises AlFeSi phases of at most about 0.05-6 wt.%.

11. The alloy composition of any one of Claims 2-10, wherein the alloy composition comprises a yield strength of about 110-170 MPa.

12. The alloy composition of any one of Claims 2-11, wherein the alloy composition comprises a bend angle of about 15-27°.

13. A process for preparing an alloy, comprising: providing an initial alloy composition comprising an aluminum source, wherein at least 30 wt.% of the aluminum source comprises scrap aluminum; melting the initial alloy composition to form an initial melted alloy; measuring at least one of a hard factor, an advanced sludge factor, or a combination thereof of the initial alloy composition; combining the initial melted alloy with a performance improving additive to form an adjusted melted alloy; and cooling the adjusted melted alloy to form an as-cast alloy.

14. The process of Claim 13, further comprising die-casting the adjusted melted alloy.

15. The process of Claim 14, wherein die-casting is high-pressure die-casting (HPDC).

16. The process of Claim 15, wherein the adjusted melted alloy comprises a casting flow length under HPDC conditions of about 1-5 m.

17. The process of any one of Claims 13-16, wherein the aluminum source comprises virgin aluminum of about 0.1-90 wt.%.

18. The process of any one of Claims 13-17, combining the initial melted alloy with the performance improving additive selected from the group consisting of Mn, Mo, Cr, Ni, Mg, V, Sr, Si, and combinations thereof.

19. The process of any one of Claims 13-18, wherein the adjusted melted alloy is substantially free of virgin aluminum.

20. The process of any one of Claims 13-19, wherein measuring the hard factor comprises calculating a sum of Mg wt.%, Cu wt.%, Zn wt.%, or combinations thereof.

21. The process of any one of Claims 13-20, wherein measuring the advanced sludge factor comprises calculating a sum of Fe wt.%, Mn wt.%, V wt.%, Cr wt.%, Co wt.%, Ni wt.%, Mo wt.%, or combinations thereof.

22. The process of any one of Claims 13-21, further comprising injection molding the adjusted melted alloy prior to cooling.