Magnesium Alloys and Methods of Making and Use Thereof

This application is a division of U.S. application Ser. No. 17/764,389 filed Mar. 28, 2022, which is a U.S. National Stage application filed under 35 U.S.C. § 371 of PCT/US2020/053065 filed Sep. 28, 2020, which claims the benefit of priority to U.S. Provisional Application No. 62/908,077, filed Sep. 30, 2019, which is hereby incorporated herein by reference in its entirety.

This invention was made with government support under Grant No. DE-EE0007756 awarded by the Department of Energy. The government has certain rights in the invention.

Magnesium (Mg), the lightest structural metal, and its alloys with high specific strength and low density are promising lightweight materials for industrial applications in automotive, aerospace, and electronic sectors. However, compared to commercial aluminum alloys and steels, there are only limited applications of Mg alloys owing to their low strength, poor ductility, and poor formability at room temperature. Thus, there is an urgent need to improve the mechanical performance of Mg sheet alloys at room temperature, especially for high-volume industrial applications such as the automotive market. The compositions, methods, and systems discussed herein addresses these and other needs.

In accordance with the purposes of the disclosed compositions, methods, and systems as embodied and broadly described herein, the disclosed subject matter relates to magnesium alloys and methods of making and use thereof.

For example, disclosed herein are magnesium alloys comprising: from 1 to 1.5 wt. % Zn, from 1 to 1.4 wt. % Al, from 0.2 to 0.7 wt. % Ca, from 0.2 to 0.4 wt. % Ce, from 0.1 to 0.8 wt. % Mn, and the balance comprising Mg. In some examples, the magnesium alloy comprises from 1 to 1.25 wt. % Zn. In some examples, the magnesium alloy comprises 1 wt. % Zn. In some examples, the magnesium alloy comprises from 1 to 1.2 wt. % Al. In some examples, the magnesium alloy comprises 1 wt. % Al. In some examples, the magnesium alloy comprises from 0.2 to 0.5 wt. % Ca. In some examples, the magnesium alloy comprises 0.3 wt. % Ca. In some examples, the magnesium alloy comprises from 0.2 to 0.3 wt. % Ce. In some examples, the magnesium alloy comprises 0.2 wt. % Ce. In some examples, the magnesium alloy comprises from 0.2 to 0.6 wt. % Mn. In some examples, the magnesium alloy comprises 0.4 wt. % Mn. In some examples, the magnesium alloy comprises from 1 to 1.25 wt. % Zn, from 1 to 1.2 wt. % Al, from 0.2 to 0.5 wt. % Ca, from 0.2 to 0.3 wt. % Ce, from 0.2 to 0.6 wt. % Mn, and the balance comprising Mg. In some examples, the magnesium alloy comprises 1 wt. % Zn, 1 wt. % Al, 0.3 wt. % Ca, 0.2 wt. % Ce, 0.4 wt. % Mn, and the balance comprising Mg. In some examples, the Zn, Al, Ca, Ce, and Mn are substantially dissolved in the magnesium alloy. In some examples, the magnesium alloy is microalloyed. In some examples, the magnesium alloy has an average grain size of from 5 μm to 14 μm.

The magnesium alloy can, for example, have a high strength. In some examples, the magnesium alloy has a yield strength of 200 MPa or more, 225 MPa or more, or 250 MPa or more.

The magnesium alloy can, for example, have a high ductility. In some examples, the magnesium alloy has an elongation to failure of 25% or more, 28% or more, 30% or more.

In some examples, the magnesium alloy is formable at room temperature. In some examples, the magnesium alloy has an Index Erichsen value of 6 mm or more, 7 mm or more, or 8 mm or more at room temperature.

Also described herein are objects comprising the magnesium alloys described herein. Also described herein are sheets comprising the magnesium alloys described herein, wherein the sheets can have an average thickness of from 0.5 mm to 5 mm, from 0.8 mm to 2 mm, or from 0.8 mm to 1.5 mm. Also described herein are articles of manufacture comprising the magnesium alloys described herein, the objects described herein, or the sheets described herein.

Also described herein are methods of use of the magnesium alloys described herein, the objects described herein, the sheets described herein, or the articles of manufacture described herein, the method comprising using the magnesium alloy, the object, or the sheet in an automotive, aerospace, or electronic application.

Also described herein are methods of making a magnesium alloy based object comprising the magnesium alloys described herein, the methods of making the magnesium alloy based object comprising: heating an object comprising a preliminary magnesium alloy at a first temperature for a first amount of time; wherein the preliminary magnesium alloy comprises a first intermetallic phase having a melting temperature, a second intermetallic phase having a melting temperature, a third intermetallic phase having a melting temperature, and an alloy phase having a solidus temperature; wherein the melting temperature of the first intermetallic phase is lower than the melting temperature of the second intermetallic phase, the melting temperature of the third intermetallic phase, and the solidus temperature of the alloy phase; wherein the melting temperature of the second intermetallic phase is lower than the melting temperature of the third intermetallic phase and the solidus temperature of the alloy phase; wherein the melting temperature of the third intermetallic phase is higher than the solidus temperature of the alloy phase; wherein the first temperature is above the melting temperature of the first intermetallic phase, below the melting temperature of the second intermetallic phase, below the melting temperature of the third intermetallic phase, and below the solidus temperature of the alloy phase; thereby substantially dissolving the first intermetallic phase into the alloy phase to form an object comprising a first intermediate magnesium alloy, the first intermediate magnesium alloy comprising the second intermetallic phase, the third intermetallic phase, and the alloy phase; heating the object comprising the first intermediate magnesium alloy at a second temperature for a second amount of time; wherein the second temperature is above the melting temperature of the second intermetallic phase, below the melting temperature of the third intermetallic phase, and below the solidus temperature of the alloy phase; thereby substantially dissolving the second intermetallic phase into the alloy phase to form an object comprising a second intermediate magnesium alloy, the second intermediate magnesium alloy comprising the third intermetallic phase and the alloy phase; and heating the object comprising the second intermediate magnesium alloy at a third temperature for a third amount of time; wherein the third temperature is above the melting temperature of the third intermetallic phase; thereby substantially dissolving the third intermetallic phase into the alloy phase and minimizing incipient melting of the alloy phase to form the magnesium alloy based object. In some examples, the methods further comprise determining the first temperature, the first amount of time, the second temperature, the second amount of time, the third temperature, the third amount of time, or a combination thereof.

In some examples, the first temperature is from 10° C. to 200° C. above the melting temperature of the first intermetallic phase. In some examples, the first temperature is from 250° C. to 325° C. (e.g., from 300° C. to 325° C.). In some examples, the first temperature is 320° C. In some examples, the first amount of time is from 1 hour to 24 hours, from 2 hours to 20 hours, from 3 hours to 18 hours, or from 4 hours to 16 hours.

In some examples, the second temperature is from 10° C. to 120° C. above the melting temperature of the second intermetallic phase. In some examples, the second temperature is from 325° C. to 450° C. (e.g., from 430° C. to 450° C.). In some examples, the second temperature is 440° C. In some examples, the second amount of time is from 1 hour to 24 hours, from 2 hours to 20 hours, from 3 hours to 18 hours, or from 4 hours to 16 hours.

In some examples, the third temperature is from 10° C. to 50° C. above the melting temperature of the third intermetallic phase. In some examples, the third temperature is from 450° C. to 500° C. (e.g., from 460° C. to 500° C.). In some examples, the third temperature is 480° C. In some examples, the third amount of time is from 0.1 hours to 3 hours, 0.2 hours to 2.4 hours, or from 0.3 hours to 2 hours.

In some examples, the first intermetallic phase comprises AlMn, CaMgZn, AlMn, or a combination thereof. In some examples, the second intermetallic phase comprises AlCa. In some examples, the third intermetallic phase comprises AlCaMg.

In some examples, the magnesium alloy based object comprises a substantially homogeneous matrix comprising the alloy phase.

In some examples, the methods further comprise thermomechanically treating the magnesium alloy based object by heating the magnesium alloy based object at a fourth temperature for a fourth amount of time and, subsequently, mechanically treating the magnesium alloy based object. In some examples, the methods further comprise repeating the thermomechanical treatment. In some examples, the magnesium alloy based object exhibits improved mechanical properties after thermomechanical treatment. In some examples, the magnesium alloy based object exhibits improved yield strength and/or ductility after thermomechanical treatment.

In some examples, the fourth temperature is above room temperature and below the solidus temperature. In some examples, the fourth temperature is from 10° C. to 250° C. below the solidus temperature. In some examples, the fourth temperature is from 350° C. to 550° C. In some examples, the fourth temperature is 450° C. In some examples, the fourth amount of time is from 1 minute to 1 hour, from 1 minute to 30 minutes, or from 1 minute to 10 minutes. In some examples, the fourth amount of time is 5 minutes. In some examples, the methods further comprise determining the fourth temperature and/or the fourth amount of time.

In some examples, mechanically treating the magnesium alloy based object comprises rolling the magnesium alloy based object. In some examples, the magnesium alloy based object has an average thickness and rolling the magnesium alloy based object reduces the average thickness of the magnesium alloy based object. In some examples, the average thickness of the magnesium alloy based object is reduced by 1% to 85%. In some examples, mechanically treating the magnesium alloy based object comprises extrusion and/or forging.

In some examples, the methods further comprise casting the object comprising the preliminary magnesium alloy. In some examples, the methods further comprise determining the composition of the preliminary magnesium alloy and/or the magnesium alloy. In some examples, the methods further comprise determining the amount of Zn to include in the magnesium alloy, the amount of Al to include in the magnesium alloy, the amount of Ca to include in the magnesium alloy, the amount of Ce to include in the magnesium alloy, the amount of Mn to include in the magnesium alloy, or a combination thereof.

Also described herein are magnesium alloy based objects made by the methods described herein. In some examples, the magnesium alloy based object has a yield strength of 200 MPa or more, 225 MPa or more, or 250 MPa or more. In some examples, the magnesium alloy an elongation to failure of 25% or more, 28% or more, 30% or more. In some examples, the magnesium alloy based object has an Index Erichsen value of 6 mm or more, 7 mm or more, or 8 mm or more at room temperature. In some examples, the magnesium alloy based object has an average thickness of from 0.5 mm to 5 mm, from 0.8 mm to 2 mm, or from 0.8 mm to 1.5 mm. In some examples, the magnesium alloy has an average grain size of from 5 μm to 14 μm. Also described herein are methods of use of the magnesium alloy based objects described herein, the method comprising using the magnesium alloy based object in an automotive, aerospace, or electronic application. Also described herein are articles of manufacture comprising the magnesium alloy based objects described herein.

Additional advantages of the disclosed compositions, systems, and methods will be set forth in part in the description which follows, and in part will be obvious from the description. The advantages of the disclosed compositions, systems, and methods will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosed systems and methods, as claimed.

The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.

The compositions, methods, and systems described herein may be understood more readily by reference to the following detailed description of specific aspects of the disclosed subject matter and the Examples included therein.

Before the present compositions, methods, and systems are disclosed and described, it is to be understood that the aspects described below are not limited to specific synthetic methods or specific reagents, as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting.

Also, throughout this specification, various publications are referenced. The disclosures of these publications in their entireties are hereby incorporated by reference into this application in order to more fully describe the state of the art to which the disclosed matter pertains. The references disclosed are also individually and specifically incorporated by reference herein for the material contained in them that is discussed in the sentence in which the reference is relied upon.

In this specification and in the claims that follow, reference will be made to a number of terms, which shall be defined to have the following meanings.

Throughout the description and claims of this specification the word “comprise” and other forms of the word, such as “comprising” and “comprises,” means including but not limited to, and is not intended to exclude, for example, other additives, components, integers, or steps.

As used in the description and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a composition” includes mixtures of two or more such compositions, reference to “an agent” includes mixtures of two or more such agents, reference to “the component” includes mixtures of two or more such components, and the like.

“Optional” or “optionally” means that the subsequently described event or circumstance can or cannot occur, and that the description includes instances where the event or circumstance occurs and instances where it does not.

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 understood that throughout this specification the identifiers “first” and “second” are used solely to aid in distinguishing the various components and steps of the disclosed subject matter. The identifiers “first” and “second” are not intended to imply any particular order, amount, preference, or importance to the components or steps modified by these terms.

References in the specification and concluding claims to parts by weight of a particular element or component in a composition denotes the weight relationship between the element or component and any other elements or components in the composition or article for which a part by weight is expressed. Thus, in a compound containing 2 parts by weight of component X and 5 parts by weight component Y, X and Y are present at a weight ratio of 2:5, and are present in such ratio regardless of whether additional components are contained in the compound.

A weight percent (wt. %) of a component, unless specifically stated to the contrary, is based on the total weight of the formulation or composition in which the component is included.

Disclosed herein are magnesium alloys comprising Zn, Al, Ca, Ce, Mn, and Mg. The Zn, Al, Ca, Ce, and Mn can, in some examples, be substantially dissolved in the magnesium alloy. In some examples, the magnesium alloy is microalloyed. The magnesium alloy can, for example, comprise from 1 to 1.5 wt. % Zn, from 1 to 1.4 wt. % Al, from 0.2 to 0.7 wt. % Ca, from 0.2 to 0.4 wt. % Ce, from 0.1 to 0.8 wt. % Mn, and the balance comprising Mg.

The magnesium alloy can, for example, comprise 1 wt. % or more Zn (e.g., 1.05 wt. % or more, 1.1 wt. % or more, 1.15 wt. % or more, 1.2 wt. % or more, 1.25 wt. % or more, 1.3 wt. % or more, 1.35 wt. % or more, or 1.4 wt. % or more). In some examples, the magnesium alloy can comprise 1.5 wt. % or less Zn (e.g., 1.45 wt. % or less, 1.4 wt. % or less, 1.35 wt. % or less, 1.3 wt. % or less, 1.25 wt. % or less, 1.2 wt. % or less, 1.15 wt. % or less, 1.1 wt. % or less, or 1.05 wt. % or less). The amount of Zn in the magnesium alloy can range from any of the minimum values described above to any of the maximum values described above. For example, the magnesium alloy can comprise from 1 to 1.5 wt. % Zn (e.g., from 1 wt. % to 1.45 wt. %, from 1 wt. % to 1.25 wt. %, from 1 wt. % to 1.15 wt. %, or from 1 wt. % to 1.05 wt. %). In some examples, the magnesium alloy can comprise 1 wt. % Zn.

The magnesium alloy can, for example, can comprise 1 wt. % or more Al (e.g., 1.05 wt. % or more, 1.1 wt. % or more, 1.15 wt. % or more, 1.2 wt. % or more, 1.25 wt. % or more, or 1.3 wt. % or more). In some examples, the magnesium alloy can comprise 1.4 wt. % or less Al (e.g., 1.35 wt. % or less, 1.3 wt. % or less, 1.25 wt. % or less, 1.2 wt. % or less, 1.15 wt. % or less, 1.1 wt. % or less, or 1.05 wt. % or less). The amount of Al in the magnesium alloy can range from any of the minimum values described above to any of the maximum values described above. For example, the magnesium alloy can comprise from 1 to 1.4 wt. % Al (e.g., from 1 wt. % to 1.3 wt. %, from 1 wt. % to 1.2 wt. %, or from 1 wt. % to 1.1 wt. %). In some examples, the magnesium alloy can comprise 1 wt. % Al.

The magnesium alloy can, for example, comprise 0.2 wt. % or more Ca (e.g., 0.25 wt. % or more, 0.3 wt. % or more, 0.35 wt. % or more, 0.4 wt. % or more, 0.45 wt. % or more, 0.5 wt. % or more, 0.55 wt. % or more, or 0.6 wt. % or more). In some examples, the magnesium alloy can comprise 0.7 wt. % or less Ca (e.g., 0.65 wt. % or less, 0.6 wt. % or less, 0.55 wt. % or less, 0.5 wt. % or less, 0.45 wt. % or less, 0.4 wt. % or less, 0.35 wt. % or less, 0.3 wt. % or less, or 0.25 wt. % or less). The amount of Ca in the magnesium alloy can range from any of the minimum values described above to any of the maximum values described above. For example, the magnesium alloy can comprise from 0.2 to 0.7 wt. % Ca (e.g., from 0.2 wt. % to 0.6 wt. %, from 0.2 wt. % to 0.5 wt. %, or from 0.2 wt. % to 0.4 wt. %). In some examples, the magnesium alloy can comprise 0.3 wt. % Ca.

The magnesium alloy can, for example, comprise 0.2 wt. % or more Ce (e.g., 0.25 wt. % or more, 0.3 wt. % or more, or 0.35 wt. % or more). In some examples, the magnesium alloy can comprise 0.4 wt. % or less Ce (e.g., 0.35 wt. % or less, 0.3 wt. % or less, or 0.25 wt. % or less). The amount of Ce in the magnesium alloy can range from any of the minimum values described above to any of the maximum values described above. For example, the magnesium alloy can comprise from 0.2 to 0.4 wt. % Ce (e.g., from 0.2 wt. % to 0.35 wt. %, from 0.2 wt. % to 0.3 wt. %, or from 0.2 wt. % to 0.25 wt. %). In some examples, the magnesium alloy can comprise 0.2 wt. % Ce.

The magnesium alloy can, for example, comprise 0.1 wt. % or more Mn (e.g., 0.15 wt. % or more, 0.2 wt. % or more, 0.25 wt. % or more, 0.3 wt. % or more, 0.35 wt. % or more, 0.4 wt. % or more, 0.45 wt. % or more, 0.5 wt. % or more, 0.55 wt. % or more, 0.6 wt. % or more, 0.65 wt. % or more, or 0.7 wt. % or more). In some examples, the magnesium alloy can comprise 0.8 wt. % or less Mn (e.g., 0.75 wt. % or less, 0.7 wt. % or less, 0.65 wt. % or less, 0.6 wt. % or less, 0.55 wt. % or less, 0.5 wt. % or less, 0.45 wt. % or less, 0.4 wt. % or less, 0.35 wt. % or less, 0.3 wt. % or less, 0.25 wt. % or less, 0.2 wt. % or less, or 0.15 wt. % or less). The amount of Mn in the magnesium alloy can range from any of the minimum values described above to any of the maximum values described above. For example, the magnesium alloy can comprise from 0.1 to 0.8 wt. % Mn (e.g., from 0.15 wt. % to 0.75 wt. %, from 0.2 wt. % to 0.6 wt. %, or from 0.3 wt. % to 0.5 wt. %). In some examples, the magnesium alloy comprises 0.4 wt. % Mn.

The magnesium alloy, can, for example, from 1 to 1.25 wt. % Zn, from 1 to 1.2 wt. % Al, from 0.2 to 0.5 wt. % Ca, from 0.2 to 0.3 wt. % Ce, from 0.2 to 0.6 wt. % Mn, and the balance comprising Mg. In some examples, the magnesium alloy comprises 1 wt. % Zn, 1 wt. % Al, 0.3 wt. % Ca, 0.2 wt. % Ce, 0.4 wt. % Mn, and the balance comprising Mg.

The magnesium alloys described herein can have a high strength. For example, the magnesium alloy can have a yield strength of 200 MPa or more (e.g., 205 MPa or more, 210 MPa or more, 215 MPa or more, 220 MPa or more, 225 MPa or more, 230 MPa or more, 235 MPa or more, 240 MPa or more, 245 MPa or more, 250 MPa or more, 260 MPa or more, 270 MPa or more, or 275 MPa or more). Yield strength can be determined using methods known in the art, for example ASTM test standard, ASTM E8/E8M—16a Standard Test Methods for Tension Testing of Metallic Materials. As used herein, the strength is determined by measurement on a Tensile frame (MTS brand Criterion Model 43) with a laser extensometer (EIR Le-01); the machine produced a Stress vs. Strain plot that includes yield stress, Ultimate Tensile stress, and amount of strain at fracture which can be converted to ductility.

The magnesium alloys described herein can have a high ductility. For example, the magnesium alloy can have an elongation to failure of 25% or more (e.g., 26% or more, 27% or more, 28% or more, 29% or more, 30% or more, 31% or more, 32% or more, 33% or more, 34% or more, or 35% or more). Ductility can be determined using methods known in the art. As used herein, the ductility is determined by measurement on a Tensile frame (MTS brand Criterion Model 43) with a laser extensometer (EIR Le-01); the machine produced a Stress vs. Strain plot that includes yield stress, Ultimate Tensile stress, and amount of strain at fracture which can be converted to ductility. The magnesium alloys described herein can be formable at room temperature. As used herein, room temperature is meant to include temperatures of 20-30° C. For example, the magnesium alloy can have an Index Erichsen value of 6 mm or more (e.g., 7 mm or more, 8 mm or more, 9 mm or more, or 10 mm or more) at room temperature. Erichsen cupping tests can be performed using methods known in the art, for example ISO 20482, 2003. As used herein, Erichsen cupping tests were carried out on rectangular specimens using a hemispherical punch with a diameter of 20 mm at room temperature. Punch speed and blank-holder force were ˜5.6 mm/min and 10 kN, respectively. The graphite lubrication was used on the tool.

The magnesium alloy can, for example, have an average grain size of 5 micrometers (microns, μm) or more (e.g., 5.5 μm or more, 6 μm or more, 6.5 μm or more, 7 μm or more, 7.5 μm or more, 8 μm or more, 8.5 μm or more, 9 μm or more, 9.5 μm or more, 10 μm or more, 10.5 μm or more, 11 μm or more, 11.5 μm or more, 12 μm or more, 12.5 μm or more, or 13 μm or more). In some examples, the magnesium alloy can have an average grain size of 14 μm or less (e.g., 13.5 μm or less, 13 μm or less, 12.5 μm or less, 12 μm or less, 11.5 μm or less, 11 μm or less, 10.5 μm or less, 10 μm or less, 9.5 μm or less, 9 μm or less, 8.5 μm or less, 8 μm or less, 7.5 μm or less, 7 μm or less, 6.5 μm or less, or 6 μm or less). The average grain size of the magnesium alloy can range from any of the minimum values described above to any of the maximum values described above. For example, the magnesium alloy can have an average grain size of from 5 μm to 14 μm (e.g., from 5 μm to 9.5 μm, from 9.5 μm to 14 μm, from 5 μm to 8 μm, from 8 μm to 11 μm, from 11 μm to 14 μm, from 5 μm to 12 μm, from 7 μm to 14 μm, or from 7 μm to 12 μm). Grain size can be determined using methods known in the art. As used herein, average grain size is measured using ASTM Standard E112-13, section 12, General intercept method.

Also described herein are sheets comprising any of the magnesium alloys described herein (e.g., magnesium alloy sheets). In some examples, the magnesium alloy sheets can have an average thickness of 0.5 millimeters (mm) or more (e.g., 0.6 mm or more, 0.7 mm or more, 0.8 mm or more, 0.9 mm or more, 1.0 mm or more, 1.1 mm or more, 1.2 mm or more, 1.3 mm or more, 1.4 mm or more, 1.5 mm or more, 1.6 mm or more, 1.7 mm or more, 1.8 mm or more, 1.9 mm or more, 2.0 mm or more, 2.5 mm or more, 3 mm or more, 3.5 mm or more, or 4 mm or more). In some examples, the magnesium alloy sheets can have an average thickness of 5 mm or less (e.g., 4.5 mm or less, 4 mm or less, 3.5 mm or less, 3 mm or less, 2.5 mm or less, 2 mm or less, 1.9 mm or less, 1.8 mm or less, 1.7 mm or less, 1.6 mm or less, 1.5 mm or less, 1.4 mm or less, 1.3 mm or less, 1.2 mm or less, 1.1 mm or less, 1.0 mm or less, 0.9 mm or less, 0.8 mm or less, or 0.7 mm or less). The average thickness of the magnesium alloy sheets can range from any of the minimum values described above to any of the maximum values described above. For example, the magnesium alloy sheets can have an average thickness of from 0.5 mm to 5 mm (e.g., from 0.5 mm to 4 mm, from 0.5 mm to 3 mm, from 0.5 mm to 2.5 mm, from 0.5 mm to 2 mm, from 0.8 mm to 2 mm, or from 0.8 mm to 1.5 mm).

Also described herein are objects and articles of manufacture comprising any of the magnesium alloys described herein. Also described herein are methods of use of the magnesium alloys, objects, sheets, and articles of manufacture described herein, the methods comprising using the magnesium alloys, objects, sheets, or articles of manufacture in an automotive, aerospace, or electronic application. Also described herein are methods of use of the magnesium alloys described herein, the methods comprising using the magnesium alloys in plate, forging and extraction applications, e.g., for a variety of industries.

Also described herein are methods of making a magnesium alloy based object comprising any of the magnesium alloys described herein, the method comprising heating an object comprising a preliminary magnesium alloy. The term “preliminary magnesium alloy” is used herein to refer to a magnesium alloy before it has undergone a heat treatment as disclosed herein. It is not meant to imply that the preliminary magnesium alloy is not yet a magnesium alloy (e.g., a metal element). Rather, a preliminary magnesium alloy is meant to refer to a magnesium alloy that has intermetallic phases present (e.g., 2 or more intermetallic phases, 3 or more intermetallic phases, etc.). In some examples, the preliminary magnesium alloy comprises a first intermetallic phase, a second intermetallic phase, a third intermetallic phase, and an alloy phase. “Phase,” as used herein, generally refers to a region of a material which is a distinct and physically separate portion of a heterogeneous system. The term “phase” does not imply that the material making up a phase is a chemically pure substance, but merely that the chemical and/or physical properties of the material making up the phase are essentially uniform throughout the material, and that these chemical and/or physical properties differ significantly from the chemical and/or physical properties of another phase within the material. Examples of physical properties include density, thickness, aspect ratio, specific surface area, porosity, dimensionality, and melting temperature. Examples of chemical properties include chemical composition. In some examples, the first intermetallic phase can comprise a plurality of intermetallic compounds wherein each of the plurality of intermetallic compounds have a melting temperature that is distinct from the melting temperature of the second intermetallic phase, the melting temperature of the third intermetallic phase, and the solidus temperature. In some examples, he first intermetallic phase can comprise a plurality of intermetallic compounds wherein each of the plurality of intermetallic compounds have a melting temperature that is substantially the same.

In some examples, the first intermetallic phase can comprise AlMn, CaMgZn, AlMn, or a combination thereof. In some examples, the second intermetallic phase comprises AlCa. In some examples, the third intermetallic phase comprises AlCaMg.

The first intermetallic phase has a melting temperature, the second intermetallic phase has a melting temperature, the third intermetallic phase has a melting temperature, and the alloy phase having a solidus temperature; wherein the melting temperature of the first intermetallic phase is lower than the melting temperature of the second intermetallic phase, the melting temperature of the third intermetallic phase, and the solidus temperature of the alloy phase; wherein the melting temperature of the second intermetallic phase is lower than the melting temperature of the third intermetallic phase and the solidus temperature of the alloy phase; and wherein the melting temperature of the third intermetallic phase is higher than the solidus temperature of the alloy phase. The methods disclosed herein can comprise heating an object comprising a preliminary magnesium alloy at a first temperature for a first amount of time; wherein the first temperature is above the melting temperature of the first intermetallic phase, below the melting temperature of the second intermetallic phase, below the melting temperature of the third intermetallic phase, and below the solidus temperature of the alloy phase.

The first temperature can, for example, be above the melting temperature of the first intermetallic phase by 10° C. or more (e.g., 20° C. or more, 30° C. or more, 40° C. or more, 50° C. or more, 60° C. or more, 70° C. or more, 80° C. or more, 90° C. or more, 100° C. or more, 110° C. or more, 120° C. or more, 130° C. or more, 140° C. or more, 150° C. or more, 160° C. or more, 170° C. or more, or 180° C. or more). In some examples, the first temperature can be above the melting temperature of the first intermetallic phase by 200° C. or less (e.g., 190° C. or less, 180° C. or less, 170° C. or less, 160° C. or less, 150° C. or less, 140° C. or less, 130° C. or less, 120° C. or less, 110° C. or less, 100° C. or less, 90° C. or less, 80° C. or less, 70° C. or less, 60° C. or less, 50° C. or less, 40° C. or less, or 30° C. or less). The first temperature can be above the melting temperature of the first intermetallic phase by an amount that ranges from any of the minimum values described above to any of the maximum values described above. For example, the first temperature can be from 10° C. to 200° C. above the melting temperature of the first intermetallic phase (e.g., from 10° C. to 100° C., from 100° C. to 200° C., from 10° C. to 50° C., from 50° C. to 100° C., from 100° C. to 150° C., from 150° C. to 200° C., from 10° C. to 190° C., from 20° C. to 200° C., or from 20° C. to 190° C.).