Aluminum alloys with high impurity tolerances via alloying with cerium

Abstract

Described herein are aluminum alloys, including secondary aluminum alloys, incorporating cerium (e.g., from 0.05% to 1% by weight Ce). The inclusion of Ce can drive the formation of Ce-rich intermetallic phases within the aluminum alloys. These Ce-rich intermetallic phases can act as a sink or collector for Cu and Mg impurities and refine Fe-phases. The reduction of free Cu and Mg via Ce addition, along with refinement of Fe-intermetallics, can result in aluminum alloys that exhibit improved ductility as compared to otherwise identical aluminum alloys lacking Ce.

Description

[0001] ALUMINUM ALLOYS WITH HIGH IMPURITY TOLERANCES VIA ALLOYING WITH CERIUM

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims benefit of priority of U.S. Provisional Application No. 63 / 586,080, filed September 28, 2023, which is hereby incorporated herein by reference.

[0004] STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0005] This invention was made with government support under grant / contract no. DE- EE0007897 awarded by the Department of Energy. The government has certain rights in the invention.

[0006] BACKGROUND

[0007] Aluminum (Al) casting alloys are widely used in the transportation industry due to their low density and range of mechanical properties. The most common Al-alloys are casting alloys with silicon (Si) as the primary alloying addition. As the transportation sector moves to decrease global emissions, the use of lightweight alloys like Al-Si alloys has significantly increased in recent years. However, the embodied energy of primary aluminum alloys produced from bauxite ore is high and offsets a considerable amount of the emission savings from reduced vehicle weight. As a result, secondary (recycled) aluminum produced from scrap has become increasingly popular due to easy recycling combined with only around 5% of the energy required to produce primary aluminum. The currently available secondary alloys, such as A380 with a composition of Al with 7.5-9.5% Si, 3-4% Cu, <2.0% Fe, <3.0% Zn, <0.1% Mg (all compositions in wt%), act as a sink for most impurities and are not suitable for all applications. Production of secondary alloys leads to appreciable amounts of Mg, Cu, Fe and Zn contamination, which can be adjusted to some extent by using sorted alloy scrap, and Mg impurity can be reduced via chlorination although it is costly and damaging to the environment.

[0008] Structural alloys, which represent a significant portion of aluminum applications for automotive applications, have the strictest impurity tolerance limits of Al-Si casting alloys, reducing the potential of scrap materials for alloy manufacture. Primary structural alloys have impurity tolerances of <0.25% Fe and do not permit any Cu or Zn. These alloys are typically manufactured using high-pressure die-casting (HPDC) which exhibit fast cooling rates. The application of structural alloys requires high ductility, which is not possible with currently available secondary alloys like A380. Structural Al-Si alloys are typically alloyed with a small amount of Mg (0.1-0.4%) to provide strength to the Al-Si binary alloy. Using sorted scrap, the impurity levels of secondary structural alloys can be significantly reduced compared to A380, but still range from 0.3-0.7% Mg, 0.3-1.0% Cu, and 0.4-1.0% Fe. As a consequence, these alloys still exhibit significantly reduced mechanical properties as compared to primary alloys.

[0009] Accordingly, there remains a need for secondary aluminum alloys with improved properties.

[0010] SUMMARY

[0011] Described herein are aluminum alloys incorporating cerium (e.g., from 0.05% to 1% by weight Ce). The inclusion of Ce can drive the formation of Ce-rich intermetallic phases within the aluminum alloys. These Ce-rich intermetallic phases can act as a sink or collector for Cu and Mg impurities (as well as Fe to a lesser extent). Further, these Ce-rich phases can nucleate around the same temperatures as Fe-containing intermetallic phases at high cooling rates and have the ability to refine the Fe-phases as compared to an otherwise identical aluminum alloy lacking Ce. The reduction of free Cu and Mg via Ce addition, along with refinement of Fe- intermetallics can result in aluminum alloys that exhibit improved ductility as compared to otherwise identical aluminum alloys lacking Ce. In some embodiments, the inclusion of Ce can afford alloys that meet the required properties of common structural applications currently using primary alloys.

[0012] For example, described herein are aluminum alloys comprising from 6% to 12% by weight Si; from 0.1% to 1% by weight Fe; from 0.05% to 1% by weight Ce; and the balance comprising Al and optionally additional components.

[0013] In some embodiments, the Ce is present in an effective amount to induce the formation of a Ce-rich intermetallic phase within the alloy. In some embodiments, the Ce is present in an effective amount to refine a Fe intermetallic phase within the alloy.

[0014] In some embodiments, the aluminum alloy comprises from greater than 8% to 12% by weight Si.

[0015] In some embodiments, the aluminum alloy comprises from greater than 0.2% to 1% by weight Fe. In some embodiments, the ratio of Ce to Fe is less than 1.2: 1. For example, in some embodiments, the ratio of Ce to Fe is from 0.3: 1 to 1.1 : 1, such as from 0.5: 1 to 1 : 1.

[0016] In some embodiments, the additional components comprise Mg, Cu, Zn, Mn, Cr, Sr, or a combination thereof.

[0017] In some embodiments, the aluminum alloy further comprises Mn, Cr, or a combination thereof, and wherein the Mn, Cr, or a combination thereof is present in an effective amount to promote the formation of a less-detrimental Fe intermetallic phase within the alloy.

[0018] In some embodiments, the aluminum alloy further comprises Cu, Mg, or a combination thereof, and wherein the Ce is present in an effective amount to act as a sink for Cu and Mg impurities within the alloy.

[0019] In some embodiments, the aluminum alloy further comprises from 0.01% to 0.7% by weight Mg.

[0020] In some embodiments, the aluminum alloy further comprises from 0.001% to 1% by weight Cu.

[0021] In some embodiments, the aluminum alloy further comprises from 0.001% to 1% by weight Zn.

[0022] In some embodiments, the aluminum alloy further comprises from 0.001% to 0.8% by weight Mn.

[0023] In some embodiments, the aluminum alloy further comprises from 0.001% to 0.2% by weight Cr.

[0024] In some embodiments, the aluminum alloy further comprises from 0.005% to 0.015% by weight Sr.

[0025] In certain embodiments, the aluminum alloy comprises from 6-12% by weight Si, from 0.05-1.0% by weight Ce; from 0.01-0.7% by weight Mg, from 0.001-1.0% by weight Cu, from 0.001-1.0% by weight Zn, from 0.1-1.0% by weight Fe, from 0.001-0.8% by weight Mn, from 0.001-0.2% by weight Cr, and the balance comprising Al and optionally additional components. In certain embodiments, the aluminum alloy further comprises from 0.005% to 0.015% by weight Sr.

[0026] In certain embodiments, the aluminum alloy comprises from 6-12% by weight Si, from 0.05-1.0% by weight Ce; from 0.01-0.7% by weight Mg, from 0.001-1.0% by weight Cu, from 0.001-1.0% by weight Zn, from greater than 0.2% to 1.0% by weight Fe, from 0.001-0.8% by weight Mn, from 0.001-0.2% by weight Cr, and the balance comprising Al and optionally additional components. In certain embodiments, the aluminum alloy further comprises from 0.005% to 0.015% by weight Sr. In certain embodiments, the aluminum alloy comprises from greater than 8% to 12% by weight Si, from 0.05-1.0% by weight Ce; from 0.01-0.7% by weight Mg, from 0.001-1.0% by weight Cu, from 0.001-1.0% by weight Zn, from greater than 0.2% to 1.0% by weight Fe, from 0.001-0.8% by weight Mn, from 0.001-0.2% by weight Cr, and the balance comprising Al and optionally additional components. In certain embodiments, the aluminum alloy further comprises from 0.005% to 0.015% by weight Sr.

[0027] In some embodiments, the aluminum alloy is a secondary aluminum alloy.

[0028] In certain embodiments, the aluminum alloy comprises a high pressure die cast alloy.

[0029] Also described herein are methods of forming a secondary aluminum alloy. These methods can comprise heating a quantity of raw materials, at least a portion of which comprises secondary production raw materials until at least a substantial majority thereof melts to become by weight approximately from 6% to 12% by weight Si; from 0.1% to 1% by weight Fe; from 0.05% to 1% by weight Ce; and the balance comprising Al and optionally additional components; placing said heated quantity of raw material into a mold that substantially defines a shape of a casting; and cooling the melted quantity of raw materials. In some embodiments, the method further comprises determining whether the presence of at least one alloying ingredient is within tolerance; and adjusting an amount of at least one of said alloying ingredients that is outside said tolerance.

[0030] In some embodiments, the quantity of raw materials comprises from greater than 8% to 12% by weight Si.

[0031] In some embodiments, the quantity of raw materials comprises from greater than 0.2% to 1% by weight Fe.

[0032] In some embodiments, the ratio of Ce to Fe in the quantity of raw materials is less than 1.2: 1. For example, in some embodiments, the the ratio of Ce to Fe in the quantity of raw materials is from 0.3: 1 to 1.1 : 1, such as from 0.5: 1 to 1 : 1.

[0033] In some embodiments, the additional components comprise Mg, Cu, Zn, Mn, Cr, Sr, or a combination thereof.

[0034] In some embodiments, the quantity of raw materials further comprises from 0.01% to 0.7% by weight Mg.

[0035] In some embodiments, the quantity of raw materials further comprises from 0.001% to 1% by weight Cu.

[0036] In some embodiments, the quantity of raw materials further comprises from 0.001% to 1% by weight Zn. In some embodiments, the quantity of raw materials further comprises from 0.001% to 0.8% by weight Mn.

[0037] In some embodiments, the quantity of raw materials further comprises from 0.001% to 0.2% by weight Mn.

[0038] In some embodiments, the quantity of raw materials further comprises from 0.005% to 0.015% by weight Sr.

[0039] In certain embodiments, the quantity of raw materials comprises from 6-12% by weight Si, from 0.05-1.0% by weight Ce; from 0.01-0.7% by weight Mg, from 0.001-1.0% by weight Cu, from 0.001 - 1.0% by weight Zn, from 0.1-1.0% by weight F e, from 0.001-0.8% by weight Mn, from 0.001-0.2% by weight Cr, and the balance comprising Al and optionally additional components. In certain embodiments, the aluminum alloy further comprises from 0.005% to 0.015% by weight Sr.

[0040] In certain embodiments, the quantity of raw materials comprises from 6-12% by weight Si, from 0.05-1.0% by weight Ce; from 0.01-0.7% by weight Mg, from 0.001-1.0% by weight Cu, from 0.001-1.0% by weight Zn, from greater than 0.2% to 1.0% by weight Fe, from 0.001- 0.8% by weight Mn, from 0.001-0.2% by weight Cr, and the balance comprising Al and optionally additional components. In certain embodiments, the aluminum alloy further comprises from 0.005% to 0.015% by weight Sr.

[0041] In certain embodiments, the quantity of raw materials comprises from greater than 8% to 12% by weight Si, from 0.05-1.0% by weight Ce; from 0.01-0.7% by weight Mg, from 0.001- 1.0% by weight Cu, from 0.001-1.0% by weight Zn, from greater than 0.2% to 1.0% by weight Fe, from 0.001-0.8% by weight Mn, from 0.001-0.2% by weight Cr, and the balance comprising Al and optionally additional components. In certain embodiments, the aluminum alloy further comprises from 0.005% to 0.015% by weight Sr.

[0042] In some embodiments, a majority of the aluminum present in the quantity of raw materials comprises secondary production aluminum.

[0043] In some embodiments, the mold comprises a sand mold, a lost foam mold, a die cast mold, a permanent (gravity) mold, or a combination thereof.

[0044] In some embodiments, the heating takes place in a furnace and the cooling takes place in the mold.

[0045] In some embodiments, the heating comprises overheating in order to substantially eliminate any residual atomic cluster that may be present in the heated quantity of raw material.

[0046] In some embodiments, the method further comprises verifying the casting quality of the secondary aluminum alloy. In some embodiments, verifying the casting quality of the secondary aluminum alloy can comprise receiving a sample of the secondary aluminum alloy; generating a microstructure image corresponding to a location of interest in the sample; measuring at least one indicia within the image; and correlating the indicia with the presence of at least alloy constituent or at least one contaminant within the secondary aluminum alloy.

[0047] In some embodiments, at least one of the receiving, the generating, and the measuring comprises performing a metallographic analysis. The metallographic analysis can be performed by a microstructure image analysis system with at least one algorithm programmed therein to measure at least one phase fraction. In certain embodiments, the indicia comprises an iron intermetallic phase volume fraction.

[0048] DESCRIPTION OF DRAWINGS

[0049] Figure 1A shows the results of CALPHAD (Computer Coupling of Phase Diagrams and Thermochemistry) simulations were performed to evaluate the effect of Ce additions in equilibrium and Scheil (solidification conditions) to Al-8.5Si-0.35Mg-0.7Fe.

[0050] Figure IB shows the results of CALPHAD simulations were performed to evaluate the effect of Ce additions in equilibrium and Scheil (solidification conditions) to Al-8.5Si-3.5Cu- l.OFe.

[0051] Figure 2 includes TEM images showing Ce and Fe phases identified in samples of AlSiMgFe-O.lCe, AlSiMgFe-l.OCe, and AlSiCuFe-l.OCe.

[0052] Figure 3 shows TEM images comparing the microstructure of AlSiMgFe and AlSiCuFe alloys including 0wt% Ce, 0.1wt% Ce, and 1.0wt% Ce. The images show the refinement of Fe- intermetallics with Ce addition.

[0053] Figure 4 shows TEM images comparing the microstructure of AlSiMgFe including 0.0wt% Ce and 0.25wt% Ce. The images show the refinement of Fe-intermetallics with Ce addition.

[0054] Figure 5A shows the results of thermal analysis of AlSiMgFe-lCe and AlSiMgFe-2Ce.

[0055] Figure 5B shows the results of thermal analysis of AlSiCuFe-lCe and AlSiCuFe-2Ce.

[0056] Figure 6 is a plot showing the yield strength (YS, MPa) and ultimate tensile strength (UTS, MPa) of AlSiMgFe-xCe and AlSiCuFe-xCe alloys including varying amounts of Ce from 0wt% to lwt%.

[0057] Figure 7 is a plot showing the % elongation (MPa) of AlSiMgFe-xCe and AlSiCuFe-xCe alloys including varying amounts of Ce from 0wt% to lwt%.

[0058] Figure 8 is a plot showing the hardness of AlSiMgFe-xCe and AlSiCuFe-xCe alloys including varying amounts of Ce from 0wt% to lwt%. DETAILED DESCRIPTION

[0059] A number of embodiments of the disclosure have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims.

[0060] Definitions

[0061] To facilitate understanding of the disclosure set forth herein, a number of terms are defined below. Unless defined otherwise, all technical and scientific terms used herein generally have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Publications cited herein and the materials for which they are cited are specifically incorporated by reference.

[0062] The term “comprising” and variations thereof as used herein is used synonymously with the term “including” and variations thereof and are open, non-limiting terms. Although the terms “comprising” and “including” have been used herein to describe various embodiments, the terms “consisting essentially of’ and “consisting of’ can be used in place of “comprising” and “including” to provide for more specific embodiments of the invention and are also disclosed. Other than where noted, all numbers expressing quantities of ingredients, reaction conditions, geometries, dimensions, and so forth used in the specification and claims are to be understood at the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, to be construed in light of the number of significant digits and ordinary rounding approaches.

[0063] As used in this specification and the following claims, the terms “comprise” (as well as forms, derivatives, or variations thereof, such as “comprising” and “comprises”) and “include” (as well as forms, derivatives, or variations thereof, such as “including” and “includes”) are inclusive (i.e., open-ended) and do not exclude additional elements or steps. For example, the terms "comprise" and / or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, 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. Accordingly, these terms are intended to not only cover the recited element(s) or step(s), but may also include other elements or steps not expressly recited. Furthermore, as used herein, the use of the terms “a”, “an”, and “the” when used in conjunction with an element may mean “one,” but it is also consistent with the meaning of “one or more,” “at least one,” and “one or more than one.” Therefore, an element preceded by “a” or “an” does not, without more constraints, preclude the existence of additional identical elements. The use of the term “about” applies to all numeric values, whether or not explicitly indicated. This term generally refers to a range of numbers that one of ordinary skill in the art would consider as a reasonable amount of deviation to the recited numeric values (i.e., having the equivalent function or result). For example, this term can be construed as including a deviation of ±10 percent of the given numeric value provided such a deviation does not alter the end function or result of the value. Therefore, a value of about 1% can be construed to be a range from 0.9% to 1.1%. Furthermore, a range may be construed to include the start and the end of the range. For example, a range of 10% to 20% (i.e., range of 10%-20%) can includes 10% and also includes 20%, and includes percentages in between 10% and 20%, unless explicitly stated otherwise herein.

[0064] It is understood that when combinations, subsets, groups, etc. of elements are disclosed (e.g., combinations of components in a composition, or combinations of steps in a method), that while specific reference of each of the various individual and collective combinations and permutations of these elements may not be explicitly disclosed, each is specifically contemplated and described herein.

[0065] Ranges can be expressed herein as from “about” one particular value, and / or to “about” another particular value. By “about” is meant within 5% of the value, e.g., within 4, 3, 2, or 1% of the value. When such a range is expressed, another aspect includes from the one particular value and / or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another aspect. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint. It is also understood that there are a number of values disclosed herein, and that each value is also herein disclosed as “about” that particular value in addition to the value itself. For example, if the value “10” is disclosed, then “about 10” is also disclosed.

[0066] As used herein, the terms "may," "optionally," and "may optionally" are used interchangeably and are meant to include cases in which the condition occurs as well as cases in which the condition does not occur. Thus, for example, the statement that a formulation "may include an excipient" is meant to include cases in which the formulation includes an excipient as well as cases in which the formulation does not include an excipient.

[0067] Reference will now be made in detail to specific aspects of the disclosed materials, compounds, compositions, articles, and methods, examples of which are illustrated in the accompanying Examples and Figures. Alloys

[0068] Described herein are aluminum alloys incorporating cerium (e.g., from 0.05% to 1% by weight Ce). The alloying element cerium (Ce) can be used to increase the impurity tolerances of aluminum alloys generated from scrap structural alloys, including in which at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or 100% of the aluminum used to form the alloy comes from scrap structural alloys. Ce is a by-product of other rare-earth mining and extraction and therefore is relatively affordable and abundant for alloying in aluminum alloys. This makes cerium a good choice for micro-alloying additions to secondary structural alloys. By increasing impurity tolerance, the alloys described herein can offer significant cost savings when preparing secondary aluminum alloys by (i) decreasing the need for high-purity scrap and / or allowing for the use of more impure scrap (different scrap sources) without compromising the properties of the resulting secondary aluminum alloys; (ii) decreasing the cost of chlorination which is currently used to decrease Mg content in secondary alloy processing; or (iii) a combination thereof. The alloys described herein can also contribute to the total decrease in emissions of the transportation industry while increasing alloy sustainability.

[0069] The inclusion of Ce can drive the formation of Ce-rich intermetallic phases within the aluminum alloys. These Ce-rich intermetallic phases can act as a sink or collector for Cu and Mg impurities (as well as Fe to a lesser extent). Further, these Ce-rich phases can nucleate around the same temperatures as Fe-containing intermetallic phases at high cooling rates and have the ability to refine the Fe-phases as compared to an otherwise identical aluminum alloy lacking Ce. The reduction of free Cu and Mg via Ce addition, along with refinement of Fe- intermetallics can result in aluminum alloys that exhibit improved ductility as compared to otherwise identical aluminum alloys lacking Ce. In some embodiments, the inclusion of Ce can afford alloys that meet the required properties of common structural applications currently using primary alloys.

[0070] For example, described herein are aluminum alloys comprising from 6% to 12% by weight Si; from 0.1% to 1% by weight Fe; from 0.05% to 1% by weight Ce; and the balance comprising Al and optionally additional components. In some embodiments, the additional components can comprise Mg, Cu, Zn, Mn, Cr, Sr, or a combination thereof.

[0071] In some embodiments, the silicon can be present in an amount of at least 6% by weight, based on the total weight of the aluminum alloy (e.g., at least 7% by weight, at least 8% by weight, at least 9% by weight, at least 10% by weight, or at least 11% by weight). In some embodiments, the silicon can be present in an amount of 12% by weight or less, based on the total weight of the aluminum alloy (e.g., 11% by weight or less, 10% by weight or less, 9% by weight or less, 8% by weight or less, or 7% by weight or less).

[0072] The silicon can be present in an amount ranging from any of the minimum values described above to any of the maximum values described above. For example, in some embodiments, the silicon can be present in an amount ranging from 6% by weight to 12% by weight, based on the total weight of the aluminum alloy (e.g., from 6% by weight to 11% by weight, from 6% by weight to 10% by weight, from 6% by weight to 9% by weight, from 6% by weight to 8% by weight, from 6% by weight to 7% by weight, from 7% by weight to 11% by weight, from 7% by weight to 10% by weight, from 7% by weight to 9% by weight, from 7% by weight to 8% by weight, from 8% by weight to 11% by weight, from 8% by weight to 10% by weight, from 8% by weight to 9% by weight, from 9% by weight to 11% by weight, from 9% by weight to 10% by weight, or from 10% by weight to 11% by weight).

[0073] In some embodiments, the iron can be present in the aluminum alloy in an amount greater than or equal to 0.1 % by weight, based on the total weight of the aluminum alloy (e.g., greater than or equal to 0.2 % by weight, greater than or equal to 0.3 % by weight, greater than or equal to 0.4 % by weight, greater than or equal to 0.5 % by weight, greater than or equal to 0.6 % by weight, greater than or equal to 0.7 % by weight, greater than or equal to 0.8 % by weight, or greater than or equal to 0.9 % by weight). In some embodiments, the iron can be present in an amount of 1% by weight or less, based on the total weight of the aluminum alloy (e.g., 0.9% by weight or less, 0.8% by weight or less, 0.7% by weight or less, 0.6% by weight or less, 0.5% by weight or less, 0.4% by weight or less, 0.3% by weight or less, or 0.2% by weight or less).

[0074] The iron can be present in an amount ranging from any of the minimum values described above to any of the maximum values described above. For example, in some embodiments, the iron is present in an amount ranging from 0.1 % by weight to 1 % by weight, based on the total weight of the aluminum alloy, (e.g., from 0.1 % by weight to 0.9 % by weight, from 0.1 % by weight to 0.8 % by weight, from 0.1 % by weight to 0.7 % by weight, from 0.1 % by weight to 0.6 % by weight, from 0.1 % by weight to 0.5 % by weight, from 0.1 % by weight to 0.4 % by weight, from 0.1 % by weight to 0.3 % by weight, from 0.1 % by weight to 0.2 % by weight, from 0.2 % by weight to 1 % by weight, from 0.2 % by weight to 0.9 % by weight, from 0.2 % by weight to 0.8 % by weight, from 0.2 % by weight to 0.7 % by weight, from 0.2 % by weight to 0.6 % by weight, from 0.2 % by weight to 0.5 % by weight, from 0.2 % by weight to 0.4 % by weight, from 0.2 % by weight to 0.3 % by weight, from 0.3 % by weight to 1 % by weight, from 0.3 % by weight to 0.9 % by weight, from 0.3 % by weight to 0.8 % by weight, from 0.3 % by weight to 0.7 % by weight, from 0.3 % by weight to 0.6 % by weight, from 0.3 % by weight to 0.5 % by weight, from 0.3 % by weight to 0.4 % by weight, from 0.4% by weight to 1% by weight, from 0.4 % by weight to 0.9 % by weight, from 0.4 % by weight to 0.8 % by weight, from 0.4 % by weight to 0.7 % by weight, from 0.4 % by weight to 0.6 % by weight, from 0.4 % by weight to 0.5 % by weight, from 0.5% by weight to 1% by weight, from 0.5 % by weight to 0.9 % by weight, from 0.5 % by weight to 0.8 % by weight, from 0.5 % by weight to 0.7 % by weight, from 0.5 % by weight to 0.6 % by weight, from 0.6% by weight to 1% by weight, from 0.6 % by weight to 0.9 % by weight, from 0.6 % by weight to 0.8 % by weight, from 0.6 % by weight to 0.7 % by weight, from 0.7% by weight to 1% by weight, from 0.7 % by weight to 0.9 % by weight, from 0.7 % by weight to 0.8 % by weight, from 0.8% by weight to 1% by weight, from 0.8 % by weight to 0.9 % by weight, or from 0.9 % by weight to 1 % by weight).

[0075] In some embodiments, the Ce is present in an effective amount to induce the formation of a Ce-rich intermetallic phase within the alloy. In some embodiments, the Ce is present in an effective amount to refine a Fe intermetallic phase within the alloy.

[0076] In some embodiments, the cerium can be present in an amount of at least 0.05% by weight, based on the total weight of the aluminum alloy (e.g., at least 0.1% by weight, at least 0.15% by weight, at least 0.2% by weight, at least 0.25% by weight, at least 0.3% by weight, at least 0.35% by weight, at least 0.4% by weight, at least 0.45% by weight, at least 0.5% by weight, at least 0.55% by weight, at least 0.6% by weight, at least 0.65% by weight, at least 0.7% by weight, at least 0.75% by weight, at least 0.8% by weight, at least 0.85% by weight, at least 0.9% by weight, or at least 0.95% by weight). In some embodiments, the cerium can be present in an amount of 1% by weight or less, based on the total weight of the aluminum alloy (e.g., 0.95% by weight or less, 0.9% by weight or less, 0.85% by weight or less, 0.8% by weight or less, 0.75% by weight or less, 0.7% by weight or less, 0.65% by weight or less, 0.6% by weight or less, 0.55% by weight or less, 0.5% by weight or less, 0.45% by weight or less, 0.4% by weight or less, 0.35% by weight or less, 0.3% by weight or less, 0.25% by weight or less, 0.2% by weight or less, 0.15% by weight or less, or 0.1% by weight or less).

[0077] The cerium can be present in an amount ranging from any of the minimum values described above to any of the maximum values described above. For example, in some embodiments, the cerium can be present in an amount ranging from 0.05% by weight to 1% by weight, based on the total weight of the aluminum alloy (e.g., from 0.1% by weight to 1% by weight, from 0.1% by weight to 0.9% by weight, from 0.1% by weight to 0.8% by weight, from 0.1% by weight to 0.7% by weight, from 0.1% by weight to 0.6% by weight, from 0.1% by weight to 0.5% by weight, from 0.1% by weight to 0.4% by weight, from 0.1% by weight to 0.3% by weight, from 0.1% by weight to 0.2% by weight, from 0.2% by weight to 1% by weight, from 0.2% by weight to 0.9% by weight, from 0.2% by weight to 0.8% by weight, from 0.2% by weight to 0.7% by weight, from 0.2% by weight to 0.6% by weight, from 0.2% by weight to 0.5% by weight, from 0.2% by weight to 0.4% by weight, from 0.2% by weight to 0.3% by weight, from 0.3% by weight to 1% by weight, from 0.3% by weight to 0.9% by weight, from 0.3% by weight to 0.8% by weight, from 0.3% by weight to 0.7% by weight, from 0.3% by weight to 0.6% by weight, from 0.3% by weight to 0.5% by weight, from 0.3% by weight to 0.4% by weight, from 0.4% by weight to 1% by weight, from 0.4% by weight to 0.9% by weight, from 0.4% by weight to 0.8% by weight, from 0.4% by weight to 0.7% by weight, from 0.4% by weight to 0.6% by weight, from 0.4% by weight to 0.5% by weight, from 0.5% by weight to 1% by weight, from 0.5% by weight to 0.9% by weight, from 0.5% by weight to 0.8% by weight, from 0.5% by weight to 0.7% by weight, from 0.5% by weight to 0.6% by weight, from 0.6% by weight to 1% by weight, from 0.6% by weight to 0.9% by weight, from 0.6% by weight to 0.8% by weight, from 0.6% by weight to 0.7% by weight, from 0.7% by weight to 1% by weight, from 0.7% by weight to 0.9% by weight, from 0.7% by weight to 0.8% by weight, from 0.8% by weight to 1% by weight, from 0.8% by weight to 0.9% by weight, or from 0.9% by weight to 1% by weight).

[0078] In some embodiments, the cerium and the iron are present in the alloy at a ratio of Ce to Fe of less than 1.2: 1 (e.g., 1.1 : 1 or less, 1 : 1 or less, 0.9: 1 or less 0.8: 1 or less, 0.7: 1 or less, 0.6: 1 or less, 0.5: 1 or less, or 0.4: 1 or less). In some embodiments, the cerium and the iron are present in the alloy at a ratio of Ce to Fe of at least 0.3: 1 (e.g., at least 0.4: 1, at least 0.5: 1, at least 0.6: 1, at least 0.7: 1, at least 0.8: 1, at least 0.9: 1, at least 1 : 1, or at least 1.1 : 1).

[0079] The cerium and the iron are present in the alloy at a ratio of Ce to Fe ranging from any of the minimum values described above to any of the maximum values described above. For example, in some embodiments, the ratio of Ce to Fe is from 0.3: 1 to 1.1 : 1, such as from 0.5: 1 to 1 : 1.

[0080] In some embodiments, the aluminum alloy further comprises Mn, Cr, or a combination thereof, and wherein the Mn, Cr, or a combination thereof is present in an effective amount to promote the formation of a less-detrimental Fe intermetallic phase within the alloy.

[0081] In some embodiments, the aluminum alloy further comprises Cu, Mg, or a combination thereof, and wherein the Ce is present in an effective amount to act as a sink for Cu and Mg impurities within the alloy.

[0082] In some embodiments, the aluminum alloy can include magnesium. In some embodiments, the magnesium can be present in an amount of at least 0.01% by weight, based on the total weight of the aluminum alloy (e.g., at least 0.05% by weight, at least 0.1% by weight, at least 0.15% by weight, at least 0.2% by weight, at least 0.25% by weight, at least 0.3% by weight, at least 0.35% by weight, at least 0.4% by weight, at least 0.45% by weight, at least 0.5% by weight, at least 0.55% by weight, at least 0.6% by weight, or at least 0.65% by weight). In some embodiments, the magnesium can be present in an amount of 0.7% by weight or less, based on the total weight of the aluminum alloy (e.g., 0.65% by weight or less, 0.6% by weight or less, 0.55% by weight or less, 0.5% by weight or less, 0.45% by weight or less, 0.4% by weight or less, 0.35% by weight or less, 0.3% by weight or less, 0.25% by weight or less, 0.2% by weight or less, 0.15% by weight or less, 0.1% by weight or less, or 0.05% by weight or less).

[0083] The magnesium can be present in an amount ranging from any of the minimum values described above to any of the maximum values described above. For example, in some embodiments, the magnesium can be present in an amount ranging from 0.01% to 0.7% by weight Mg.

[0084] In some embodiments, the aluminum alloy can include copper. In some embodiments, the copper can be present in an amount of at least 0.001% by weight, based on the total weight of the aluminum alloy (at least 0.005% by weight, at least 0.01% by weight, at least 0.05% by weight, at least 0.1% by weight, at least 0.2% by weight, at least 0.3% by weight, at least 0.4% by weight, at least 0.5% by weight, at least 0.6% by weight, at least 0.7% by weight, at least 0.8% by weight, or at least 0.9% by weight). In some embodiments, the copper can be present in an amount of 1% by weight or less, based on the total weight of the aluminum alloy (e.g., 0.9% by weight or less, 0.8% by weight or less, 0.7% by weight or less, 0.6% by weight or less, 0.5% by weight or less, 0.4% by weight or less, 0.3% by weight or less, 0.2% by weight or less, 0.1% by weight or less, 0.05% by weight or less, 0.01% by weight or less, or 0.005% by weight or less).

[0085] The copper can be present in an amount ranging from any of the minimum values described above to any of the maximum values described above. For example, in some embodiments, the copper can be present in an amount ranging from 0.001% to 1% by weight.

[0086] In some embodiments, the aluminum alloy can include zinc. In some embodiments, the zinc can be present in an amount of at least 0.001% by weight, based on the total weight of the aluminum alloy (at least 0.005% by weight, at least 0.01% by weight, at least 0.05% by weight, at least 0.1% by weight, at least 0.2% by weight, at least 0.3% by weight, at least 0.4% by weight, at least 0.5% by weight, at least 0.6% by weight, at least 0.7% by weight, at least 0.8% by weight, or at least 0.9% by weight). In some embodiments, the zinc can be present in an amount of 1% by weight or less, based on the total weight of the aluminum alloy (e.g., 0.9% by weight or less, 0.8% by weight or less, 0.7% by weight or less, 0.6% by weight or less, 0.5% by weight or less, 0.4% by weight or less, 0.3% by weight or less, 0.2% by weight or less, 0.1% by weight or less, 0.05% by weight or less, 0.01% by weight or less, or 0.005% by weight or less).

[0087] The zinc can be present in an amount ranging from any of the minimum values described above to any of the maximum values described above. For example, in some embodiments, the zinc can be present in an amount ranging from 0.001% to 1% by weight.

[0088] In some embodiments, the aluminum alloy can include manganese. In some embodiments, the manganese can be present in an amount of at least 0.001% by weight, based on the total weight of the aluminum alloy (at least 0.005% by weight, at least 0.01% by weight, at least 0.05% by weight, at least 0.1% by weight, at least 0.2% by weight, at least 0.3% by weight, at least 0.4% by weight, at least 0.5% by weight, at least 0.6% by weight, or at least 0.7% by weight). In some embodiments, the manganese can be present in an amount of 0.8% by weight or less, based on the total weight of the aluminum alloy (e.g., 0.7% by weight or less, 0.6% by weight or less, 0.5% by weight or less, 0.4% by weight or less, 0.3% by weight or less, 0.2% by weight or less, 0.1% by weight or less, 0.05% by weight or less, 0.01% by weight or less, or 0.005% by weight or less).

[0089] The manganese can be present in an amount ranging from any of the minimum values described above to any of the maximum values described above. For example, in some embodiments, the manganese can be present in an amount ranging from 0.001% to 0.8% by weight.

[0090] In some embodiments, the aluminum alloy can include chromium. In some embodiments, the chromium can be present in an amount of at least 0.001% by weight, based on the total weight of the aluminum alloy (at least 0.005% by weight, at least 0.01% by weight, at least 0.05% by weight, or at least 0.1% by weight). In some embodiments, the chromium can be present in an amount of 0.2% by weight or less, based on the total weight of the aluminum alloy (e.g., 0.1% by weight or less, 0.05% by weight or less, 0.01% by weight or less, or 0.005% by weight or less).

[0091] The chromium can be present in an amount ranging from any of the minimum values described above to any of the maximum values described above. For example, in some embodiments, the chromium can be present in an amount ranging from 0.001% to 0.2% by weight.

[0092] In some embodiments, the aluminum alloy further comprises strontium. In some embodiments, the strontium can be present in an amount of at least 0.005% by weight, based on the total weight of the aluminum alloy (e.g., at least 0.0075% by weight, at least 0.01% by weight, or at least 0.015% by weight). In some embodiments, the strontium can be present in an amount of 0.015% by weight or less, based on the total weight of the aluminum alloy (e.g., 0.01% by weight or less, or 0.0075% by weight or less).

[0093] The strontium can be present in an amount ranging from any of the minimum values described above to any of the maximum values described above. For example, in some embodiments, the strontium is present in an amount of from 0.005% to 0.015% by weight Sr.

[0094] In certain embodiments, the aluminum alloy comprises from 6-12% by weight Si, from 0.05-1.0% by weight Ce; from 0.01-0.7% by weight Mg, from 0.001-1.0% by weight Cu, from 0.001-1.0% by weight Zn, from 0.1-1.0% by weight Fe, from 0.001-0.8% by weight Mn, from 0.001-0.2% by weight Cr, and the balance comprising Al and optionally additional components. In certain embodiments, the aluminum alloy further comprises from 0.005% to 0.015% by weight Sr.

[0095] In certain embodiments, the aluminum alloy comprises from 6-12% by weight Si, from 0.05-1.0% by weight Ce; from 0.01-0.7% by weight Mg, from 0.001-1.0% by weight Cu, from 0.001-1.0% by weight Zn, from greater than 0.2% to 1.0% by weight Fe, from 0.001-0.8% by weight Mn, from 0.001-0.2% by weight Cr, and the balance comprising Al and optionally additional components. In certain embodiments, the aluminum alloy further comprises from 0.005% to 0.015% by weight Sr.

[0096] In certain embodiments, the aluminum alloy comprises from greater than 8% to 12% by weight Si, from 0.05-1.0% by weight Ce; from 0.01-0.7% by weight Mg, from 0.001-1.0% by weight Cu, from 0.001-1.0% by weight Zn, from greater than 0.2% to 1.0% by weight Fe, from 0.001-0.8% by weight Mn, from 0.001-0.2% by weight Cr, and the balance comprising Al and optionally additional components. In certain embodiments, the aluminum alloy further comprises from 0.005% to 0.015% by weight Sr.

[0097] In some embodiments, the aluminum alloy is a secondary aluminum alloy.

[0098] In certain embodiments, the aluminum alloy comprises a high pressure die cast alloy.

[0099] Methods

[0100] Also described herein are methods of forming a secondary aluminum alloy. These methods can comprise heating a quantity of raw materials, at least a portion of which comprises secondary production raw materials until at least a substantial majority thereof melts to become by weight approximately from 6% to 12% by weight Si; from 0.1% to 1% by weight Fe; from 0.05% to 1% by weight Ce; and the balance comprising Al and optionally additional components; placing said heated quantity of raw material into a mold that substantially defines a shape of a casting; and cooling the melted quantity of raw materials. In some embodiments, the method further comprises determining whether the presence of at least one alloying ingredient is within tolerance; and adjusting an amount of at least one of said alloying ingredients that is outside said tolerance.

[0101] In some embodiments, the quantity of raw materials comprises from greater than 8% to 12% by weight Si.

[0102] In some embodiments, the quantity of raw materials comprises from greater than 0.2% to 1% by weight Fe.

[0103] In some embodiments, the ratio of Ce to Fe in the quantity of raw materials is less than 1.2: 1. For example, in some embodiments, the the ratio of Ce to Fe in the quantity of raw materials is from 0.3: 1 to 1.1 : 1, such as from 0.5: 1 to 1 : 1.

[0104] In some embodiments, the additional components comprise Mg, Cu, Zn, Mn, Cr, Sr, or a combination thereof.

[0105] In some embodiments, the quantity of raw materials further comprises from 0.01% to 0.7% by weight Mg.

[0106] In some embodiments, the quantity of raw materials further comprises from 0.001% to 1% by weight Cu.

[0107] In some embodiments, the quantity of raw materials further comprises from 0.001% to 1% by weight Zn.

[0108] In some embodiments, the quantity of raw materials further comprises from 0.001% to 0.8% by weight Mn.

[0109] In some embodiments, the quantity of raw materials further comprises from 0.001% to 0.2% by weight Mn.

[0110] In some embodiments, the quantity of raw materials further comprises from 0.005% to 0.015% by weight Sr.

[0111] In certain embodiments, the quantity of raw materials comprises from 6-12% by weight Si, from 0.05-1.0% by weight Ce; from 0.01-0.7% by weight Mg, from 0.001-1.0% by weight Cu, from 0.001 - 1.0% by weight Zn, from 0.1-1.0% by weight F e, from 0.001-0.8% by weight Mn, from 0.001-0.2% by weight Cr, and the balance comprising Al and optionally additional components. In certain embodiments, the aluminum alloy further comprises from 0.005% to 0.015% by weight Sr.

[0112] In certain embodiments, the quantity of raw materials comprises from 6-12% by weight Si, from 0.05-1.0% by weight Ce; from 0.01-0.7% by weight Mg, from 0.001-1.0% by weight Cu, from 0.001-1.0% by weight Zn, from greater than 0.2% to 1.0% by weight Fe, from 0.001- 0.8% by weight Mn, from 0.001-0.2% by weight Cr, and the balance comprising Al and optionally additional components. In certain embodiments, the aluminum alloy further comprises from 0.005% to 0.015% by weight Sr.

[0113] In certain embodiments, the quantity of raw materials comprises from greater than 8% to 12% by weight Si, from 0.05-1.0% by weight Ce; from 0.01-0.7% by weight Mg, from 0.001- 1.0% by weight Cu, from 0.001-1.0% by weight Zn, from greater than 0.2% to 1.0% by weight Fe, from 0.001-0.8% by weight Mn, from 0.001-0.2% by weight Cr, and the balance comprising Al and optionally additional components. In certain embodiments, the aluminum alloy further comprises from 0.005% to 0.015% by weight Sr.

[0114] In some embodiments, a majority of the aluminum present in the quantity of raw materials comprises secondary production aluminum. In some embodiments, sorted scrap is utilized as some or all of the raw materials. In some embodiments, sorted scrap is utilized to achieve compositions made from 50-100% scrap materials with lower levels of Cu and Fe impurities than currently produced secondary alloys.

[0115] In some embodiments, the mold comprises a sand mold, a lost foam mold, a die cast mold, a permanent (gravity) mold, or a combination thereof.

[0116] In some embodiments, the heating takes place in a furnace and the cooling takes place in the mold.

[0117] In some embodiments, the heating comprises overheating in order to substantially eliminate any residual atomic cluster that may be present in the heated quantity of raw material.

[0118] In some embodiments, the method further comprises verifying the casting quality of the secondary aluminum alloy. In some embodiments, verifying the casting quality of the secondary aluminum alloy can comprise receiving a sample of the secondary aluminum alloy; generating a microstructure image corresponding to a location of interest in the sample; measuring at least one indicia within the image; and correlating the indicia with the presence of at least alloy constituent or at least one contaminant within the secondary aluminum alloy.

[0119] In some embodiments, at least one of the receiving, the generating, and the measuring comprises performing a metallographic analysis. The metallographic analysis can be performed by a microstructure image analysis system with at least one algorithm programmed therein to measure at least one phase fraction. In certain embodiments, the indicia comprises an iron intermetallic phase volume fraction.

[0120] In some embodiments, the alloys can have suitable mechanical properties for use in structural applications. The alloys can be processed into structural components all major casting processes, i.e., sand casting, permanent mold casting, and high-pressure die casting (HPDC). In certain embodiments, the alloy can be used in a HPDC and / or high solidification rate application.

[0121] All of the compositions and methods disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. While the compositions and methods of this disclosure have been described in terms of preferred embodiments, it will be apparent to those of skill in the art that variations may be applied to the compositions and methods and in the steps or in the sequence of steps of the methods described herein without departing from the concept, spirit and scope of the disclosure. More specifically, it will be apparent that certain agents which are both chemically related may be substituted for the agents described herein while the same or similar results would be achieved. All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope and concept of the disclosure as defined by the appended claims.

[0122] By way of non-limiting illustration, examples of certain embodiments of the present disclosure are given below.

[0123] EXAMPLES

[0124] Example 1. Secondary Aluminum-Silicon Alloys for Structural Applications with High Impurity Tolerances via Alloying with Cerium

[0125] Modeling of Ce Addition to Al-Si-Fe Alloys Containing Mg and Cu

[0126] CALPHAD (Computer Coupling of Phase Diagrams and Thermochemistry) simulations were performed to evaluate the effect of Ce additions in equilibrium and Scheil (solidification conditions) to representative base compositions: Al-8.5Si-0.35Mg-0.7Fe and Al-8.5Si-3.5Cu- 1.OFe. Calculations were performed using the Termo-calc’s TCAL v. 8.1 database. The results are shown in Figure 1 A (modeling varying Ce addition to Al-8.5Si-0.35Mg-0.7Fe) and Figure IB (modeling varying Ce addition to Al-8.5Si-3.5Cu-l.0Fe). Modeling predicted the formation of three Al-Ce-Si phases for both alloy systems: AlCeSi, AlCeSi?, and ALCesSie.

[0127] Phase Analysis and Alloy Microstructure

[0128] The Ce-rich and Fe-intermetallic phases present in these alloys were evaluated using transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) energy dispersive spectroscopy (EDS). Figure 2 includes TEM images showing Ce and Fe phases identified in samples of AlSiMgFe-O.lCe, AlSiMgFe-l.OCe, and AlSiCuFe-l.OCe. The identified phases are listed with the STEM-EDS measured compositions in Table 1. The EDS results confirm that Ce-rich phases have the ability to solubilize Cu and Mg, decreasing the amount of Mg and Cu free to form other phases. Specifically, Mg exhibits a high solubility in AlCeSi?, allowing the AlCeSi2phase to serve as a Mg sink. Fe also has some solubility within the AlCeSi? phase. AlCeSiCu includes a large ratio of Cu, allowing this phase to serve as a Cu sink.

[0129] Table 1: STEM-EDS measurements for aluminum alloys with Ce (in at%).

[0130] The microstructure images shown in Figures 3 and 4 are examples from experimental alloys. Using TEM, 5-AlFeSi, visible as needles (2D), was identified in all samples including baseline alloys. 7t-AlFeMgSi was found in all AlSiMgFe-xCe alloys except at 1% Ce, with area fraction decreasing with increasing Ce. From the images in Figures 3 and 4, it is possible to see that the addition of Ce caused a refinement of the Fe-intermetallics. The microstructure evidence shows that the Ce-rich phase formation effects the Fe-intermetallics formation leading to refinement.

[0131] Thermal analysis of the alloys was also conducted. AlSiMgFe and AlSiCuFe containing lwt% and 2wt% Ce were tested to evaluate the formation of high temperature phases. The results are shown in Figures 5A (AlSiMgFe-lCe and AlSiMgFe-2Ce) and Figure 5B (AlSiCuFe- ICe and AlSiCuFe-2Ce). In all cases, aluminum was always the first phase to form. Ce phases formed around 5-AlFeSi before Cu and Mg phases.

[0132] Evaluation of the Mechanical Properties of Die Cast Secondary Aluminum Alloys

[0133] Three experimental alloys with target compositions within the alloy design range were created and cast into a steel mold providing relatively fast cooling rates (above 30K / s). The composition of the three alloys is shown in Table 2. The castings were milled to ASTM E8 subsize tensile bars using wire electric discharge machining.

[0134] Table 2: Composition of aluminum alloys subjected to mechanical testing. The tensile properties of as-cast specimens were determined according to the standard test procedures described in ASTM B557-15, entitled “Standard Test Methods for Tension Testing Wrought and Cast Aluminum- and Magnesium-Alloy Products” which is hereby incorporated by reference in its entirety. All the tests were conducted using an MTS Model 43 tensile test machine. The flat tensile bars, with a gauge length of 32 mm and width of a 6 mm, were machined from 3 mm-thick cast plates. The round tensile bars tested had a diameter of 6 mm in the gauge section. The tensile tests were performed at room temperature, with a constant strain rate of 0.005mm / s. The results are shown in Figures 6-8 as well as Table 3.

[0135] Table 3: Mechanical properties of as-cast aluminum alloys.

[0136] From the results, the addition of Ce to the alloys significantly improved the ductility of the alloy. The experimental alloys are expected to display significantly higher elongation under HPDC conditions with proper melt cleaning, similar to the reported ranges of primary structural alloys.

[0137] The compositions and methods of the appended claims are not limited in scope by the specific compositions and methods described herein, which are intended as illustrations of a few aspects of the claims and any compositions and methods that are functionally equivalent are intended to fall within the scope of the claims. Various modifications of the compositions and methods in addition to those shown and described herein are intended to fall within the scope of the appended claims. Further, while only certain representative compositions and method steps disclosed herein are specifically described, other combinations of the compositions and method steps also are intended to fall within the scope of the appended claims, even if not specifically recited. Thus, a combination of steps, elements, components, or constituents may be explicitly mentioned herein; however, other combinations of steps, elements, components, and constituents are included, even though not explicitly stated.

Claims

WHAT IS CLAIMED IS:

1. An aluminum alloy comprising: from 6% to 12% by weight Si; from 0.1% to 1% by weight Fe; from 0.05% to 1% by weight Ce; and the balance comprising Al and optionally additional components.

2. The alloy of claim 1, wherein the Ce is present in an effective amount to induce the formation of a Ce-rich intermetallic phase within the alloy.

3. The alloy of any of claims 1-2, wherein the Ce is present in an effective amount to refine a Fe intermetallic phase within the alloy.

4. The alloy of any of claims 1-3, wherein the aluminum alloy comprises from greater than 8% to 12% by weight Si.

5. The alloy of any of claims 1-4, wherein the aluminum alloy comprises from greater than 0.2% to 1% by weight Fe.

6. The alloy of any of claims 1-5, wherein the ratio of Ce to Fe is less than 1.2: 1.

7. The alloy of any of claims 1-6, wherein the ratio of Ce to Fe is from 0.3:1 to 1.1 : 1, such as from 0.5: 1 to 1 : 1.

8. The alloy of any of claims 1-7, wherein the additional components comprise Mg, Cu, Zn, Mn, Cr, Sr, or a combination thereof.

9. The alloy of any of claims 1-8, wherein the aluminum alloy further comprises Mn, Cr, or a combination thereof, and wherein the Mn, Cr, or a combination thereof is present in an effective amount to promote the formation of a less-detrimental Fe intermetallic phase within the alloy.

10. The alloy of any of claims 1-9, wherein the aluminum alloy further comprises Cu, Mg, or a combination thereof, and wherein the Ce is present in an effective amount to act as a sink for Cu and Mg impurities within the alloy.

11. The alloy of any of claims 1-10, wherein the aluminum alloy further comprises from 0.01% to 0.7% by weight Mg.

12. The alloy of any of claims 1-11, wherein the aluminum alloy further comprises from 0.001% to 1% by weight Cu.

13. The alloy of any of claims 1-12, wherein the aluminum alloy further comprises from 0.001% to 1% by weight Zn.

14. The alloy of any of claims 1-13, wherein the aluminum alloy further comprises from 0.001% to 0.8% by weight Mn.

15. The alloy of any of claims 1-14, wherein the aluminum alloy further comprises from 0.001% to 0.2% by weight Cr.

16. The alloy of any of claims 1-15, wherein the aluminum alloy further comprises from 0.005% to 0.015% by weight Sr.

17. The alloy of any of claims 1-16, wherein the aluminum alloy comprises from 6-12% by weight Si, from 0.05-1.0% by weight Ce; from 0.01-0.7% by weight Mg, from 0.001-1.0% by weight Cu, from 0.001-1.0% by weight Zn, from 0.1-1.0% by weight Fe, from 0.001-0.8% by weight Mn, from 0.001-0.2% by weight Cr, and the balance comprising Al and optionally additional components.

18. The alloy of any of claims 1-17, wherein the aluminum alloy comprises from 6-12% by weight Si, from 0.05-1.0% by weight Ce; from 0.01-0.7% by weight Mg, from 0.001-1.0% by weight Cu, from 0.001-1.0% by weight Zn, from greater than 0.2% to 1.0% by weight Fe, from 0.001-0.8% by weight Mn, from 0.001-0.2% by weight Cr, and the balance comprising Al and optionally additional components.

19. The alloy of any of claims 1-18, wherein the aluminum alloy comprises from greater than 8% to 12% by weight Si, from 0.05-1.0% by weight Ce; from 0.01-0.7% by weight Mg, from 0.001-1.0% by weight Cu, from 0.001-1.0% by weight Zn, from greater than 0.2% to 1.0% by weight Fe, from 0.001-0.8% by weight Mn, from 0.001-0.2% by weight Cr, and the balance comprising Al and optionally additional components.

20. The alloy of any of claims 17-19, wherein the aluminum alloy further comprises from 0.005% to 0.015% by weight Sr.

21. The alloy of any of claims 1-20, wherein the aluminum alloy is a secondary aluminum alloy.

22. The alloy of any of claims 1-21, wherein the aluminum alloy comprises a high pressure die cast alloy.

23. A method of forming a secondary aluminum alloy, the method comprising: heating a quantity of raw materials at least a portion of which comprises secondary production raw materials until at least a substantial majority thereof melts to become by weight approximately from 6% to 12% by weight Si; from 0.1% to 1% by weight Fe; from 0.05% to 1% by weight Ce; and the balance comprising Al and optionally additional components; placing said heated quantity of raw material into a mold that substantially defines a shape of a casting; and cooling the melted quantity of raw materials.

24. The method of claim 23, further comprising: determining whether the presence of at least one alloying ingredient is within tolerance; and adjusting an amount of at least one of said alloying ingredients that is outside said tolerance.

25. The method of any of claims 23-24, wherein the quantity of raw materials comprises from greater than 8% to 12% by weight Si.

26. The method of any of claims 23-25, wherein the quantity of raw materials comprises from greater than 0.2% to 1% by weight Fe.

27. The method of any of claims 23-26, wherein the ratio of Ce to Fe in the quantity of raw materials is less than 1.2:1.

28. The method of any of claims 23-27, wherein the ratio of Ce to Fe in the quantity of raw materials is from 0.3:1 to 1.1:1, such as from 0.5:1 to 1:1.

29. The method of any of claims 23-28, wherein the additional components comprise Mg, Cu, Zn, Mn, Cr, Sr, or a combination thereof.

30. The method of any of claims 23-29, wherein the quantity of raw materials further comprises from 0.01% to 0.7% by weight Mg.

31. The method of any of claims 23-30, wherein the quantity of raw materials further comprises from 0.001% to 1% by weight Cu.

32. The method of any of claims 23-31, wherein the quantity of raw materials further comprises from 0.001% to 1% by weight Zn.

33. The method of any of claims 23-32, wherein the quantity of raw materials further comprises from 0.001% to 0.8% by weight Mn.

34. The method of any of claims 23-33, wherein the quantity of raw materials further comprises from 0.001% to 0.2% by weight Mn.

35. The method of any of claims 23-34, wherein the quantity of raw materials further comprises from 0.005% to 0.015% by weight Sr.

36. The method of any of claims 23-35, wherein the quantity of raw materials comprises from 6-12% by weight Si, from 0.05-1.0% by weight Ce; from 0.01-0.7% by weight Mg, from 0.001-1.0% by weight Cu, from 0.001-1.0% by weight Zn, from 0.1-1.0% by weight F e, from 0.001-0.8% by weight Mn, from 0.001-0.2% by weight Cr, and the balance comprising Al and optionally additional components.

37. The method of any of claims 23-36, wherein the quantity of raw materials comprises from 6-12% by weight Si, from 0.05-1.0% by weight Ce; from 0.01-0.7% by weight Mg, from 0.001-1.0% by weight Cu, from 0.001-1.0% by weight Zn, from greater than 0.2% to 1.0% by weight Fe, from 0.001-0.8% by weight Mn, from 0.001-0.2% by weight Cr, and the balance comprising Al and optionally additional components.

38. The method of any of claims 23-37, wherein the quantity of raw materials comprises from greater than 8% to 12% by weight Si, from 0.05-1.0% by weight Ce; from 0.01-0.7% by weight Mg, from 0.001-1.0% by weight Cu, from 0.001-1.0% by weight Zn, from greater than 0.2% to 1.0% by weight Fe, from 0.001-0.8% by weight Mn, from 0.001-0.2% by weight Cr, and the balance comprising Al and optionally additional components.

39. The method of any of claims 36-38, wherein the quantity of raw materials further comprises from 0.005% to 0.015% by weight Sr.

40. The method of any of claims 23-39, wherein a majority of the aluminum present in the quantity of raw materials comprises secondary production aluminum.

41. The method of any of claims 23-40, wherein the mold comprises a sand mold, a lost foam mold, a die cast mold, a permanent (gravity) mold, or a combination thereof.

42. The method of any of claims 23-41, wherein the heating takes place in a furnace and the cooling takes place in the mold.

43. The method of any of claims 23-42, wherein the heating comprises overheating in order to substantially eliminate any residual atomic cluster that may be present in the heated quantity of raw material.

44. The method of any of claims 23-43, further comprising verifying the casting quality of the secondary aluminum alloy.

45. The method of claim 44, wherein verifying the casting quality of the secondary aluminum alloy comprises: receiving a sample of the secondary aluminum alloy;generating a microstructure image corresponding to a location of interest in the sample; measuring at least one indicia within the image; and correlating the indicia with the presence of at least alloy constituent or at least one contaminant within the secondary aluminum alloy.

46. The method of claim 45, wherein at least one of the receiving, the generating, and the measuring comprises performing a metallographic analysis.

47. The method of claim 46, wherein the metallographic analysis is performed by a microstructure image analysis system with at least one algorithm programmed therein to measure at least one phase fraction.

48. The method of any of claims 45-47, wherein the indicia comprises an iron intermetallic phase volume fraction.

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