Aluminum alloy material, aluminum alloy structural part, battery case, battery system, electric device, preparation method and use

Abstract

An aluminum alloy material, an aluminum alloy structural part, a battery case, a battery system, an electric device (6), a preparation method and a use. The aluminum alloy material comprises the following composition elements: Si, Mn, Mo, Zr, Sr, Sc, B, a matrix element Al and inevitable impurity elements, and in the aluminum alloy material, both the content of the element Mo and the content of the element Zr are low.

Description

Aluminum alloy materials, aluminum alloy structural parts, battery boxes, battery systems, electrical devices, preparation methods and applications

[0001] Related applications

[0002] This application claims priority to Chinese patent application number CN2023115989415, filed on November 27, 2023, entitled “Aluminum alloy materials, aluminum alloy structural parts, battery cases, battery systems, electrical devices, preparation methods and applications,” the entire text of which is hereby incorporated by reference. Technical Field

[0003] The present application relates to the field of aluminum alloy material technology, further to the field of battery technology, and further to aluminum alloy materials, aluminum alloy structural parts, battery cases, battery systems, electrical devices, preparation methods and applications. Background Art

[0004] The statements herein merely provide background information related to the present application and do not necessarily constitute prior art.

[0005] The battery case is a key component of the battery and plays an important role in protecting it. It not only needs to have good mechanical properties to reduce damage to the battery during impact, but also needs to be corrosion-resistant to extend the battery's lifespan. Currently, the primary material used to construct battery cases is aluminum alloy. There is a need to develop aluminum alloys that combine excellent mechanical properties with superior corrosion resistance.

[0006] Summary of the Invention

[0007] According to various embodiments and examples of the present application, an aluminum alloy material, an aluminum alloy structural member, a battery case, a battery system, an electrical device, a preparation method, and applications are provided. The aluminum alloy material has good mechanical properties and excellent corrosion resistance, and can be used as the main material of the aluminum alloy structure in the battery case, effectively extending the service life of the battery case.

[0008] In the first aspect, the present application provides an aluminum alloy material, which includes the following constituent elements: Si, Mn, Mo, Zr, Sr, Sc, B, matrix element Al and unavoidable impurity elements; the mass percentage of Mo element in the aluminum alloy material is ≤0.25%; the mass percentage of Zr element in the aluminum alloy material is ≤0.2%.

[0009] In some embodiments, an aluminum alloy material is provided, comprising the following constituent elements: Si, Mn, Mo, Zr, Sr, Sc, B, a matrix element Al, and unavoidable impurity elements;

[0010] Wherein, the aluminum alloy material includes Al-Si eutectic phase, AlB x Strengthening phase and AlSiMnSc strengthening phase, the AlB x The strengthening phase includes at least an AlB2 strengthening phase;

[0011] The mass percentage of Mo element in the aluminum alloy material is ≤0.25%;

[0012] The mass percentage of Zr element in the aluminum alloy material is ≤0.2%.

[0013] The aluminum alloy material uses Al as a matrix element, including Si (silicon) element, Mn (manganese) element, Mo (molybdenum) element, Zr (zirconium) element, Sr (strontium) element, Sc (scandium) element and B (boron) element. The matrix element Al in the aluminum alloy material forms an α-Al matrix phase, which is mainly composed of primary α-Al crystals. By adding Si element, Sc element, B element and Mn element, Al-Si eutectic phase, AlB x Strengthening phase and AlSiMnSc strengthening phase can provide aluminum alloy materials with good mechanical properties, such as mechanical strength and strength. The Si element can form an Al-Si eutectic phase with the α-Al matrix phase, which plays a strengthening role, so that the aluminum alloy material can have a microstructure mainly composed of primary α-Al crystals and Al-Si eutectic structures. The introduction of the rare earth element Sc can simultaneously improve the mechanical strength and corrosion resistance of the aluminum alloy material. It can produce a significant strengthening effect through limited solid solution and increased deformation resistance and promotion of dislocation proliferation in the form of solid solution and formation of alloy phase. The alloy phase formed by the Sc element usually includes strengthening phases such as the AlSiMnSc strengthening phase; in addition, some Sc elements can dissolve in the matrix, increase the self-corrosion potential, and some Sc elements can reduce the matrix-alloy phase potential difference and reduce the potential corrosion tendency. The B element can change the crystallization conditions of the aluminum alloy, thereby increasing the growth rate of the crystal nucleus and playing a role in refining the grains. The solubility of the B element in the Al alloy is low, and it is easy to form AlB distributed near the eutectic structure. xStrengthening phase. The Mn element can form the AlSiMnSc strengthening phase, and it also helps to demold during the smelting process and make the precipitated phase uniformly distributed. The introduction of the Sr element can modify the Al-Si eutectic structure, and can improve mechanical properties such as mechanical strength and ductility. In addition, the Sr element can also help to improve the plastic workability of the aluminum alloy, improve the mechanical properties of the aluminum alloy, and reduce the ingot homogenization time. In some known aluminum alloy materials, the mechanical properties and corrosion resistance of the aluminum alloy material can be improved by adding Mo and Zr elements, but a larger amount is often required. Among them, the Mo element can be dissolved in the aluminum crystal, which helps to promote the formation of a dense passivation film in the aluminum alloy and increase the corrosion resistance; the Zr element can hinder or inhibit the recrystallization process, thereby refining the casting structure. The aluminum alloy material provided in the first aspect of the present application can achieve good mechanical properties and excellent corrosion resistance by adding only a small amount of Mo and Zr elements through the aforementioned element design and alloy phase control. By collaboratively designing the element composition and element content in aluminum alloy materials, the prepared aluminum alloy materials can have a special microstructure, and the various elements can achieve good mechanical properties and excellent corrosion resistance through multiple synergistic effects.

[0014] In some embodiments, an aluminum alloy material is provided, which includes, by mass percentage, 8% to 11.5% of Si element, 0.05% to 0.35% of Sc element, 0.01% to 0.4% of B element, 0.3% to 1.0% of Mn element, 0.02% to 0.25% of Mo element, 0.01% to 0.2% of Zr element, 0.02% to 0.08% of Sr element, matrix element Al and the unavoidable impurity elements.

[0015] In some embodiments, the aluminum alloy material includes Al-Si eutectic phase, AlB x Strengthening phase and AlSiMnSc strengthening phase.

[0016] By rationally designing the composition and content of each element in the aluminum alloy and utilizing the multiple synergistic effects between the elements, the prepared aluminum alloy material can have a special microstructure, thereby achieving good mechanical properties and excellent corrosion resistance. Under the above element composition, the aluminum alloy material can form α-Al matrix phase, Al-Si eutectic phase, AlB xStrengthening phase and AlSiMnSc strengthening phase can provide aluminum alloy materials with good mechanical properties, such as mechanical strength, strength, etc. The Si element can form an Al-Si eutectic phase with the α-Al matrix phase, which plays a strengthening role. The introduction of the rare earth element Sc can simultaneously improve the mechanical strength and corrosion resistance of aluminum alloy materials. It can produce a significant strengthening effect through limited solid solution and increased deformation resistance, and promoted dislocation proliferation in the form of solid solution and formation of alloy phase. The alloy phase formed by the Sc element usually includes a strengthening phase such as the AlSiMnSc strengthening phase; in addition, some Sc elements can be dissolved in the matrix, increasing the self-corrosion potential, and some Sc elements can reduce the matrix-alloy phase potential difference and reduce the potential corrosion tendency. The B element can change the crystallization conditions of the aluminum alloy, thereby increasing the growth rate of the crystal nucleus, and can play a role in refining the grains. The solubility of the B element in the Al alloy is low, and it is easy to form AlB distributed near the eutectic structure. x Strengthening phase. The Mn element can form the AlSiMnSc strengthening phase, and it also helps to demold during the smelting process and make the precipitated phase uniformly distributed. The introduction of the Sr element can modify the Al-Si eutectic structure, and can improve mechanical properties such as mechanical strength and ductility. In addition, the Sr element can also help to improve the plastic workability of aluminum alloys, improve the mechanical properties of aluminum alloys, and reduce the homogenization time of ingots. The Mo element can be dissolved in aluminum crystals, which helps to promote the formation of a dense passivation film on aluminum alloys and increase corrosion resistance; the Zr element can hinder or inhibit the recrystallization process, thereby refining the casting structure. Through the overall design of the aforementioned element types and contents, good mechanical properties and excellent corrosion resistance can be better achieved with only a small amount of Mo and Zr elements.

[0017] Based on any suitable embodiment of the present application, further, in some embodiments, the aluminum alloy material satisfies one or more of the following characteristics:

[0018] The AlB x The mass fraction of the strengthening phase in the aluminum alloy material is ≤0.1%, and can be optionally 0.05% to 0.1%;

[0019] The mass fraction of the AlSiMnSc strengthening phase in the aluminum alloy material is ≤0.2%, and can be optionally 0.07% to 0.2%.

[0020] By regulating AlB x The mechanical strength of aluminum alloy materials can be adjusted by controlling the content of either or both of the AlSiMnSc strengthening phase and the AlB strengthening phase. x The content of strengthening phase is also beneficial to reduce the adverse effect of the relative corrosion resistance of the alloy. xControlling the contents of the strengthening phase and the AlSiMnSc strengthening phase in the aluminum alloy material within the aforementioned range is more conducive to achieving both good mechanical properties and excellent corrosion resistance.

[0021] Based on any suitable embodiment of the present application, further, in some embodiments, the aluminum alloy material satisfies one or more of the following characteristics:

[0022] The mass percentage of Si element in the aluminum alloy material is 8% to 11.5%, optionally 8.5% to 11.5%, and further optionally 8.5% to 11%;

[0023] The mass percentage of Sc element in the aluminum alloy material is 0.05% to 0.35%, optionally 0.1% to 0.35%, and further optionally 0.1% to 0.3%;

[0024] The mass percentage of the B element in the aluminum alloy material is 0.01% to 0.4%, optionally 0.01% to 0.25%, and further optionally 0.01% to 0.1%;

[0025] The mass percentage of the Mn element in the aluminum alloy material is 0.3% to 1.0%, optionally 0.45% to 0.95%, and further optionally 0.45% to 0.70%.

[0026] By adjusting the contents of Si, Sc, B and Mn within the above ranges, the Al-Si eutectic phase, AlB x Controlling the content of the strengthening phase and the AlSiMnSc strengthening phase is more conducive to balancing mechanical properties and corrosion resistance, and achieving both good mechanical properties and excellent corrosion resistance.

[0027] The appearance of the Al-Si eutectic phase can be achieved by regulating the Si content below the eutectic point of the Si element (about 11.7%), which is beneficial to suppressing the generation of primary silicon that is detrimental to corrosion performance.

[0028] By controlling the Sc content within the aforementioned range, it is beneficial to improve the mechanical properties and corrosion resistance while taking the cost into consideration.

[0029] By controlling the B content within the above range, it is possible to effectively refine grains and AlB x While strengthening the phase interaction, it also better inhibits AlB x The adverse effects of alloy phase corrosion.

[0030] The addition of Mn provides a reinforcing effect, primarily by dissolving in the Al matrix and increasing its strength through lattice distortion. Controlling the Mn content can adjust the content of the AlSiMnSc strengthening phase and the MnAl6 alloying phase, as well as modulating the demolding process and promoting a uniform distribution of the precipitated phase. By controlling the Mn content within the aforementioned range, the mechanical properties of the aluminum alloy are further enhanced.

[0031] Based on any appropriate embodiment of the present application, further, in some embodiments, the aluminum alloy material includes a MnAl6 alloy phase; optionally, the mass fraction of the MnAl6 alloy phase in the aluminum alloy material is 0.55% to 1.25%, and further optionally 0.45% to 1.3%.

[0032] The MnAl6 alloy phase can play a supplementary strengthening role. By adjusting the content of the MnAl6 alloy phase within the aforementioned range, it is beneficial to better play the reinforcing role. The content of the MnAl6 alloy phase can be adjusted by adjusting the content of the Mn element. Within a certain range of the Mn element content, the content of the MnAl6 alloy phase in the aluminum alloy material can be increased by increasing the Mn element content.

[0033] Based on any appropriate embodiment of the present application, further, in some embodiments, the aluminum alloy material satisfies one or more of the following characteristics: the mass percentage of Mo element in the aluminum alloy material is 0.02% to 0.25%, optionally 0.04% to 0.2%, and further optionally 0.05% to 0.1%;

[0034] The mass percentage of the Zr element in the aluminum alloy material is 0.01% to 0.2%, optionally 0.01% to 0.15%, and further optionally 0.05% to 0.15%.

[0035] Mo dissolves in aluminum crystals, promoting the formation of a dense passivation film on aluminum alloys and enhancing corrosion resistance. Zr hinders or inhibits recrystallization, thereby refining the casting structure. By controlling the contents of both elements within the aforementioned ranges, based on the aforementioned elemental composition and alloy phase design, aluminum alloy materials can achieve both good mechanical properties and excellent corrosion resistance.

[0036] Based on any appropriate embodiment of the present application, further, in some embodiments, the mass percentage of the Sr element in the aluminum alloy material is 0.02% to 0.08%, optionally 0.02% to 0.06%, and further optionally 0.02% to 0.05%.

[0037] By adjusting the Sr content, the modification effect of Sr on the Al-Si eutectic structure can be adjusted. By controlling the Sr content within a more appropriate range, it is more conducive to optimizing the mechanical properties of aluminum alloy materials.

[0038] Based on any suitable embodiment of the present application, further, in some embodiments, the aluminum alloy material includes, by mass percentage, 8.5% to 11.5% of Si element, 0.1% to 0.35% of Sc element, 0.01% to 0.25% of B element, 0.45% to 0.95% of Mn element, 0.05% to 0.2% of Mo element, 0.01% to 0.15% of Zr element, 0.02% to 0.06% of Sr element, matrix element Al and the unavoidable impurity elements.

[0039] Based on any suitable embodiment of the present application, further, in some embodiments, the aluminum alloy material includes, by mass percentage, 8.5% to 11% of Si element, 0.1% to 0.3% of Sc element, 0.01% to 0.1% of B element, 0.45% to 0.70% of Mn element, 0.05% to 0.1% of Mo element, 0.05% to 0.15% of Zr element, 0.02% to 0.05% of Sr element, matrix element Al and the unavoidable impurity elements.

[0040] Based on any appropriate embodiment of the present application, further, in some embodiments, the aluminum alloy material includes, by mass percentage, 8% to 11.5% of Si element, 0.05% to 0.35% of Sc element, 0.01% to 0.4% of B element, 0.3% to 1.0% of Mn element, 0.05% to 0.25% of Mo element, 0.01% to 0.2% of Zr element, 0.02% to 0.08% of Sr element, the unavoidable impurity elements and the balance of Al element.

[0041] Based on any appropriate embodiment of the present application, further, in some embodiments, the aluminum alloy material includes, by mass percentage, 8% to 11.5% of Si element, 0.05% to 0.35% of Sc element, 0.05% to 0.4% of B element, 0.3% to 1.0% of Mn element, 0.05% to 0.25% of Mo element, 0.01% to 0.2% of Zr element, 0.02% to 0.08% of Sr element, the unavoidable impurity elements and the balance of Al element.

[0042] By adjusting the types and contents of various elements in the aluminum alloy material, the aluminum alloy material can obtain good mechanical properties and excellent corrosion resistance within a variety of content ranges.

[0043] Based on any appropriate embodiment of the present application, further, in some embodiments, the unavoidable impurity elements include Fe.

[0044] Based on any suitable embodiment of the present application, further, in some embodiments, the aluminum alloy material satisfies one or more of the following characteristics:

[0045] The mass percentage of Fe element in the aluminum alloy material is ≤0.7%. Optionally, the mass percentage of the unavoidable impurity elements in the aluminum alloy material is <0.7%.

[0046] The aluminum alloy material includes an AlSiMnFe phase. Optionally, the mass fraction of the AlSiMnFe phase in the aluminum alloy material is ≤0.2%, and further optionally ≤0.1%;

[0047] The aluminum alloy material includes an AlSiMnFe / Sc alloy phase; optionally, the mass fraction of the AlSiMnFe / Sc alloy phase in the aluminum alloy material is ≤0.2%, and can be optionally 0.07% to 0.2%.

[0048] In the process of casting aluminum alloys, it is often inevitable that Fe impurities are present in the formed aluminum alloy. A small amount of Fe element (such as Fe content ≤ 0.7wt%) helps to demold during the casting process. However, when the Fe content is high, it is easy to reduce the corrosion resistance of the aluminum alloy material. Fe impurities can form needle-shaped AlSiMnFe phases, which have a certain strengthening effect. However, due to the large contact area between the AlSiMnFe phase and the α-Al matrix and the large potential difference, local galvanic corrosion may occur. By controlling the Fe content within a lower content range, it is helpful to reduce the adverse effects of Fe on corrosion resistance.

[0049] In addition, the introduction of Sc element can transform a part of the needle-like AlSiMnFe phase into a fine, multi-branched AlSiMnFe / Sc alloy phase, reducing the damage of the needle-like AlSiMnFe phase to the corrosion resistance.

[0050] Based on any suitable embodiment of the present application, further, in some embodiments, the aluminum alloy material satisfies one or more of the following characteristics:

[0051] The mass percentage of Mg element in the aluminum alloy material is ≤0.1%, optionally ≤0.01%, and further optionally 0%;

[0052] The mass percentage of Zn element in the aluminum alloy material is ≤0.1%, optionally ≤0.01%, and further optionally 0%;

[0053] The mass percentage of Cu element in the aluminum alloy material is ≤0.01%, and can be optionally 0%.

[0054] In some known aluminum alloy materials, one or more of Mg, Zn, and Cu are often added to achieve a strengthening effect. The aluminum alloy material provided in the first aspect can achieve good mechanical properties and excellent corrosion resistance while limiting the Mg, Zn, and Cu contents to relatively low levels.

[0055] In a second aspect of the present application, an aluminum alloy structural part is provided, which is a formed body of the aluminum alloy material described in the first aspect of the present application.

[0056] In a third aspect of the present application, a method for preparing an aluminum alloy structural part is provided, comprising the following steps:

[0057] heating and melting an aluminum ingot, adding ingredients determined according to the nominal composition of the aluminum alloy material described in the first aspect of the present application in the form of a master alloy, performing melting and refining and slagging to prepare an aluminum alloy refined melt;

[0058] Casting the aluminum alloy melt to obtain an aluminum alloy ingot;

[0059] The aluminum alloy ingot is heat treated and cooled to obtain the aluminum alloy structural part.

[0060] The aluminum alloy structural part as the formed body of the aluminum alloy material described in the first aspect of the present application can have good mechanical properties and excellent corrosion resistance, can be used as an aluminum alloy structural part in a battery case, and can effectively extend the service life of the battery case. The aluminum alloy structural part can be made by using aluminum ingots to provide matrix elements, supplemented by corresponding alloying elements, and undergoing smelting and slagging, casting, heat treatment and cooling to obtain the aluminum alloy structural part. The shape and size of the aluminum alloy structural part can be controlled by selecting a mold of corresponding shape and size in the casting step. It can be understood that the shape and size of the cooled structural part can also be adjusted to obtain an aluminum alloy structural part of the target shape and size. For example, treatment methods including but not limited to sandblasting and grinding can be used.

[0061] In a fourth aspect of the present application, a battery case is provided, wherein the battery case satisfies at least one of the following characteristics:

[0062] At least a portion of the structural members in the battery case comprises the aluminum alloy material described in the first aspect of the present application;

[0063] The battery box includes the aluminum alloy structural member described in the second aspect of the present application; and

[0064] The battery case includes an aluminum alloy structural part prepared by the method for preparing an aluminum alloy structural part described in the third aspect of the present application.

[0065] The battery case provides protection for the battery cells inside. On the one hand, the battery case needs to have good mechanical strength to reduce the damage to the battery cells when they are hit. On the other hand, the battery case is susceptible to galvanic corrosion during storage and battery cycling. Therefore, the battery case also needs to have a certain degree of corrosion resistance. The battery case made of the aforementioned aluminum alloy material or aluminum alloy structural parts can meet the requirements of both mechanical properties and corrosion resistance.

[0066] In a fifth aspect of the present application, a battery system is provided, which includes the battery case described in the fourth aspect of the present application and a battery cell located inside the battery case.

[0067] Based on any suitable embodiment of the present application, further, in some embodiments, the battery cell includes a liquid electrolyte.

[0068] In the sixth aspect of the present application, an electrical device is provided, which includes at least one of the aluminum alloy material described in the first aspect of the present application, the aluminum alloy structural part described in the second aspect of the present application, the aluminum alloy structural part obtained by the preparation method of the aluminum alloy structural part described in the third aspect of the present application, the battery case described in the fourth aspect of the present application, and the battery system described in the fifth aspect of the present application.

[0069] By using the aforementioned aluminum alloy materials, the aforementioned aluminum alloy structural parts, or the battery case including the aforementioned aluminum alloy materials or aluminum alloy structural parts in one or more of the battery system and the electrical device, it is beneficial to improve the reliability and life of the battery system and the electrical device. It can not only reduce the degree of damage to the battery when it is hit, but also improve the corrosion resistance of the battery case, including but not limited to improving the resistance to galvanic corrosion.

[0070] When the battery cells in the battery system include liquid electrolytes, higher corrosion resistance is required for the battery case. The battery system and electrical device provided above are more likely to meet storage and usage requirements.

[0071] In the seventh aspect of the present application, there is provided the use of the aluminum alloy material described in the first aspect of the present application in the preparation of at least one of aluminum alloy structural parts, battery boxes, battery systems and electrical devices.

[0072] The details of one or more embodiments and examples of the present application are set forth in the following drawings and description. Other features, objects, and advantages of the present application will become apparent from the description, drawings, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] In order to better describe and illustrate the embodiments, examples or examples provided in this application, reference may be made to one or more drawings. The additional details or examples used to describe the drawings should not be considered as limiting the scope of the disclosed application, the currently described embodiments, examples or examples, and any of the currently understood best modes of these applications. Moreover, the same figure numbers are used to represent the same components in all the drawings. It should also be noted that the drawings are drawn in a simplified form and are only used to assist in the explanation of this application for convenience and clarity. The various dimensions of each component shown in the drawings are arbitrarily shown and may be accurate or not drawn to scale. For example, in order to make the illustration clearer, the dimensions of the components are appropriately exaggerated in some places in the drawings. Unless otherwise specified, the components in the drawings are not drawn to scale. This application does not limit every dimension of every component.

[0074] In the attached figure:

[0075] FIG1 is a microstructure diagram of an aluminum alloy material in one embodiment of the present application.

[0076] FIG2 is a diagram showing the microstructure and element distribution of an aluminum alloy material in one embodiment of the present application.

[0077] FIG3 is a field emission scanning electron microscope FESEM+EDS (with energy dispersive spectrometer) point scanning diagram of an aluminum alloy material in one embodiment of the present application and analysis results of four point scanning positions therein.

[0078] Figure 4 is a curve showing the changes in mass fraction, elastic modulus, thermal conductivity and density of the AlSi9MnMoZr reference alloy material and the aluminum alloy material in one embodiment of the present application as a function of temperature (Temperature), wherein the mass fraction refers to the mass fraction of the aluminum alloy material at different temperatures relative to the initial mass of the aluminum alloy material in the unheated state, reflecting the thermal weight loss of the aluminum alloy material.

[0079] FIG5 is a potentiodynamic polarization curve of an aluminum alloy material in one embodiment of the present application, wherein the horizontal axis is the chemical potential (unit is V) and the vertical axis is the current density (A / cm 2 ).

[0080] FIG6 is an AC impedance test result of an aluminum alloy material in one embodiment of the present application.

[0081] FIG7 is a surface macroscopic morphology diagram of an aluminum alloy material at different corrosion times in a salt spray corrosion test in one embodiment of the present application.

[0082] FIG8 is a schematic diagram of sample dimensions for a tensile test of an aluminum alloy material in one embodiment of the present application.

[0083] FIG9 is a schematic diagram of a battery module according to an embodiment of the present application.

[0084] FIG10 is a schematic diagram of a battery pack according to an embodiment of the present application.

[0085] FIG. 11 is an exploded view of the battery pack shown in FIG. 10 according to an embodiment of the present application.

[0086] FIG12 is a schematic diagram of an electrical device according to an embodiment of the present application.

[0087] Explanation of the reference numerals: 1 is a battery pack; 2 is an upper case; 3 is a lower case; 4 is a battery module; 5 is a battery cell; 6 is an electrical device. DETAILED DESCRIPTION

[0088] Below, some embodiments and examples of the aluminum alloy materials, aluminum alloy structural parts, battery cases, battery systems, electrical devices, preparation methods and applications of the present application are described in detail with appropriate reference to the accompanying drawings. However, there may be cases where unnecessary detailed descriptions are omitted. For example, there are cases where detailed descriptions of well-known matters and repeated descriptions of actually the same structures are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate the understanding of those skilled in the art. In addition, the drawings and the following description are provided for those skilled in the art to fully understand the present application and are not intended to limit the subject matter described in the claims.

[0089] " scope " disclosed in the present application can be limited in the form of lower limit and upper limit, and given range is limited by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of special range. The scope limited in this way can be to include end value or not include end value, and any end value can be included or not included independently, and can be arbitrarily combined, that is, any lower limit can form a scope with any upper limit combination. For example, if the scope of 60-120 and 80-110 is listed for specific parameters, it is understood that the scope of 60-110 and 80-120 is also expected. In addition, if minimum range values ​​1 and 2 are listed, and if maximum range values ​​3,4 and 5 are also listed, then the following scope can all be expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In the present application, unless otherwise specified, numerical range " ab " represents the abbreviation of any real number combination between a and b, wherein a and b are all real numbers. For example, a numerical range of "0-5" indicates that all real numbers between "0-5" are listed herein, and "0-5" is merely an abbreviation for a combination of these values. Furthermore, when a parameter is expressed as an integer ≥ 2, this is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc. For example, when a parameter is expressed as an integer selected from "2-10", this is equivalent to listing the integers 2, 3, 4, 5, 6, 7, 8, 9, and 10.

[0090] In this application, references to "plurality," "multiple," "multiple," "several," and the like, unless otherwise specified, refer to a quantity greater than or equal to two. For example, "one or more" refers to one or greater than or equal to two. It is understood that references to "any number" of items refer to any suitable combination of multiple items, i.e., any combination of "any number" of items that is consistent with the present application and that allows for the implementation of the present application.

[0091] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0092] References to "embodiments" herein mean that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment or implementation of the present application. The appearance of such phrases in various locations in the specification does not necessarily refer to the same embodiment, nor does it necessarily refer to independent or alternative embodiments that are mutually exclusive with other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments. References to "implementations" herein have a similar understanding.

[0093] Those skilled in the art will appreciate that, in the methods of each embodiment or embodiment, the order in which each step is written does not mean a strict order of execution and constitutes any limitation to the implementation process, and the detailed order of execution of each step should be determined by its function and possible internal logic. Unless otherwise specified, all steps of the present application can be performed in sequence, or can be performed randomly, or can preferably be performed in sequence. For example, method M includes steps (a) and (b), indicating that method M may include steps (a) and (b) performed in sequence, or steps (b) and (a) performed in sequence. For another example, method M may also include step (c), indicating that step (c) can be added to method M in any order, for example, method M may include steps (a), (b) and (c), or steps (a), (c) and (b), or steps (c), (a) and (b), etc.

[0094] In this application, in open technical features or technical solutions described with words such as "contain," "include," and "include," unless otherwise specified, additional members other than the listed members are not excluded, and it can be regarded as providing both closed features or solutions consisting of the listed members and open features or solutions including additional members in addition to the listed members. For example, A includes a1, a2, and a3. Unless otherwise specified, it may also include other members or not. It can be regarded as providing both the feature or solution of "A consists of a1, a2, and a3" or "A is selected from a1, a2, and a3", and the feature or solution of "A includes not only a1, a2, and a3, but also other members."

[0095] In this application, unless otherwise specified, A (such as B) means that B is a non-limiting example of A, and it can be understood that A is not limited to B.

[0096] In this application, "optionally," "optional," and "optional" mean optional, that is, they refer to either option selected from the two parallel options of "yes" or "no." If multiple "options" appear in a technical solution, unless otherwise specified and there are no contradictions or mutual constraints, each "optional" is independent. Unless otherwise specified, the descriptions "optionally include," "optionally include," etc. in this application, using "optionally include" as an example, mean "may include or not include."

[0097] In this application, unless otherwise specified, the features or solutions corresponding to "and / or" include any one of two or more relevant listed items, and also include any and all combinations of the relevant listed items. "Any and all combinations" include any combination of any two relevant listed items, any more relevant listed items, or all relevant listed items. For example, "A and / or B" means the group consisting of A, B, and "the combination of A and B." Among them, "including A and / or B" can mean "including A, including B, and including A and B", and can also mean "including A, including B, or including A and B", which can be appropriately understood according to the sentence in which it is used.

[0098] As used herein, "combination thereof", "any combination thereof", "any combination thereof" and the like include all suitable combinations of any two or more of the listed items.

[0099] Herein, the “suitable” involved in “suitable combination”, “suitable method”, “any suitable method”, etc. shall be based on the technical solution that can implement this application.

[0100] Herein, the terms "preferred," "better," "more preferable," "suitable," "comparatively better," and "preferable" are used solely to describe preferred implementations or examples and should not be construed as limiting the scope of protection of this application. If multiple "preferred" terms appear in a technical solution, each "preferred" term is considered independent unless otherwise specified and there are no contradictions or mutual constraints.

[0101] In this application, "further", "further", "particularly", "for example", "such as", "example", "for example", etc. are used for descriptive purposes to indicate differences in content, but should not be understood as limiting the scope of protection of this application.

[0102] In this application, the terms "first," "second," "third," "fourth," etc. in "the first aspect," "the second aspect," "the third aspect," "the fourth aspect," etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or quantity, nor should they be understood as implicitly indicating the importance or quantity of the indicated technical features. Furthermore, "first," "second," "third," "fourth," etc. serve only as non-exhaustive enumeration and description, and should be understood not to constitute a closed-ended limitation on quantity.

[0103] In this application, the term "room temperature" generally refers to 4°C to 35°C, and may refer to 20°C ± 5°C. In some embodiments of this application, room temperature refers to 20°C to 30°C.

[0104] In this application, when referring to a data range, if the unit is followed only by the right endpoint, it means that the units of the left and right endpoints are the same. For example, "3~5h" or "3-5h" both mean that the units of the left endpoint "3" and the right endpoint "5" are both hours, and both have the same meaning as "3h~5h". Similarly, descriptions involving other parameters such as temperature and size are to be understood in the same manner.

[0105] The weight of the relevant components mentioned in the embodiments or examples of the present application can not only refer to the content of each component, but also represent the proportional relationship of the weights between the components. Therefore, as long as the content of the relevant components in the embodiments or examples of the present application is proportionally enlarged or reduced, it is within the scope described in the present application. Further, the weight involved in the embodiments or examples of the present application can be mass units known in the chemical industry such as μg, mg, g, and kg. Unless otherwise specified, the mass ratio is equal to the corresponding weight ratio. For example, if the mass of substance A is m1 and the weight is W1, and the mass of substance B is m2 and the weight is W2, then the mass ratio m1 / m2 of the two is numerically equal to the corresponding weight ratio W1 / W2.

[0106] In this application, unless otherwise specified, wt% represents weight percentage by weight, which is numerically equivalent to the corresponding mass percentage by mass. In this application, wt% may also be expressed as wt.%.

[0107] In this application, unless otherwise specified, the unit of percentage (%) involved in "mass percentage" and "mass fraction" may also be expressed as wt% or % (w / w).

[0108] In this application, "greater than or equal to" and "greater than or equal to" can both be expressed as "≥", "less than or equal to" and "less than or equal to" can both be expressed as "≤", "greater than" can be equivalently expressed as ">", and "less than" can be equivalently expressed as "<". In this application, unless otherwise specified, "greater than or equal to" and "≥" can be regarded as providing two solutions of "greater than" and "equal to". In this application, unless otherwise specified, "less than or equal to" and "≤" can be regarded as providing two solutions of "less than" and "equal to".

[0109] In this application, exemplary descriptions such as "in some embodiments (or examples)" and "in one embodiment (or example)" may include but are not limited to the following meanings: these solutions can be combined with other solutions in a suitable manner to form new technical solutions.

[0110] The battery case, which protects the battery cells, is not only required to have good mechanical properties to reduce damage to the battery when impacted, but also to have a certain degree of corrosion resistance to extend the battery life. Currently, the material that constitutes the battery case is mainly aluminum alloy. In some common aluminum alloys, relatively high contents of Mo and Zr are used to improve material properties, but this is expensive and the raw material source has certain limitations. It is necessary to develop aluminum alloy materials with different elemental compositions to achieve both good mechanical properties and excellent corrosion resistance.

[0111] According to various embodiments and examples of the present application, an aluminum alloy material, an aluminum alloy structural member, a battery case, a battery system, an electrical device, a preparation method, and applications are provided. The aluminum alloy material has good mechanical properties and excellent corrosion resistance, and can be used as the main material of the aluminum alloy structure in the battery case, effectively extending the service life of the battery case.

[0112] In a first aspect, the present application provides an aluminum alloy material comprising Si, Mn, Mo, Zr, Sr, Sc, B, a matrix element Al, and unavoidable impurity elements, wherein the aluminum alloy material comprises a relatively low content of Mo and Zr (e.g., a Mo content of ≤0.25 wt %, and a Zr content of ≤0.2 wt %). The aluminum alloy material exhibits excellent mechanical properties and corrosion resistance, and can be used as the main material for a battery case, thereby effectively extending the service life of the battery case.

[0113] In this application, unless otherwise specified, "aluminum alloy material is used as the main material of the battery case" means that the aluminum alloy material is used as the main material of at least a part of the structure of the battery case, and the mass proportion of the aluminum alloy material in this part of the structure can exceed 80%, further exceed 90%, and further approach 100% or be 100%. In this application, unless otherwise specified, when "aluminum alloy material is used as the main material of a structural part or product", it is allowed to add other functional components to the aluminum alloy material to further improve the material performance without reducing the basic properties of the aluminum alloy material, especially without reducing the mechanical properties and corrosion resistance. In some embodiments, the aluminum alloy material is used as a component material of the battery case. At this time, the chemical composition of at least a part of the structure or structural part of the battery case is consistent with the aluminum alloy material, and the mass proportion of the aluminum alloy material in the corresponding structure or corresponding structural part is 100%.

[0114] In this application, unless otherwise specified, "the content of a certain element" refers to the mass percentage of that element in the aluminum alloy material provided herein. For example, "the content of Mo" refers to the mass percentage of the Mo element in the aluminum alloy material, and "the content of Zr" refers to the mass percentage of the Zr element in the aluminum alloy material. Unless otherwise specified, "the content of a certain alloy phase" refers to the mass percentage of that alloy phase in the aluminum alloy material provided herein.

[0115] In some embodiments, an aluminum alloy material is provided, comprising the following constituent elements: Si, Mn, Mo, Zr, Sr, Sc, B, a matrix element Al, and unavoidable impurity elements;

[0116] Among them, aluminum alloy materials include Al-Si eutectic phase, AlB x Strengthening phase and AlSiMnSc strengthening phase, AlB x The strengthening phase includes at least an AlB2 strengthening phase;

[0117] The mass percentage of Mo element in aluminum alloy material is ≤0.25%;

[0118] The mass percentage of Zr element in the aluminum alloy material is ≤0.2%.

[0119] The aluminum alloy material uses Al as a matrix element, including Si (silicon) element, Mn (manganese) element, Mo (molybdenum) element, Zr (zirconium) element, Sr (strontium) element, Sc (scandium) element and B (boron) element. The matrix element Al in the aluminum alloy material forms an α-Al matrix phase, which is mainly composed of primary α-Al crystals. By adding Si element, Sc element, B element and Mn element, Al-Si eutectic phase, AlB xStrengthening phase and AlSiMnSc strengthening phase can provide aluminum alloy materials with good mechanical properties, such as mechanical strength and strength. The Si element can form an Al-Si eutectic phase with the α-Al matrix phase, which plays a strengthening role, so that the aluminum alloy material can have a microstructure mainly composed of primary α-Al crystals and Al-Si eutectic structures. The introduction of the rare earth element Sc can simultaneously improve the mechanical strength and corrosion resistance of the aluminum alloy material. It can produce a significant strengthening effect through limited solid solution and increased deformation resistance, and promote dislocation proliferation in the form of solid solution and formation of alloy phases. The alloy phase formed by the Sc element usually includes AlSiMnSc strengthening phase; in addition, some Sc elements can dissolve in the matrix, increase the self-corrosion potential, and some Sc elements can reduce the matrix-alloy phase potential difference and reduce the potential corrosion tendency. The B element can change the crystallization conditions of the aluminum alloy, thereby increasing the growth rate of the crystal nucleus, and can play a role in refining the grains. The solubility of the B element in the Al alloy is low, and it is easy to form AlB distributed near the eutectic structure. x Strengthening phase. The Mn element can form the AlSiMnSc strengthening phase, and it also helps to demold during the smelting process and make the precipitated phase uniformly distributed. The introduction of the Sr element can modify the Al-Si eutectic structure, and can improve mechanical properties such as mechanical strength and ductility. In addition, the Sr element can also help to improve the plastic workability of the aluminum alloy, improve the mechanical properties of the aluminum alloy, and reduce the ingot homogenization time. In some known aluminum alloy materials, the mechanical properties and corrosion resistance of the aluminum alloy material can be improved by adding Mo and Zr elements, but a larger amount is often required. Among them, the Mo element can be dissolved in the aluminum crystal, which helps to promote the formation of a dense passivation film in the aluminum alloy and increase the corrosion resistance; the Zr element can hinder or inhibit the recrystallization process, thereby refining the casting structure. The aluminum alloy material provided in the first aspect of the present application can achieve good mechanical properties and excellent corrosion resistance by adding only a small amount of Mo and Zr elements through the aforementioned element design and alloy phase control. By collaboratively designing the element composition and element content in aluminum alloy materials, the prepared aluminum alloy materials can have a special microstructure, and the various elements can achieve good mechanical properties and excellent corrosion resistance through multiple synergistic effects.

[0120] In some embodiments, an aluminum alloy material is provided, which includes, by mass percentage, 8% to 11.5% of Si element, 0.05% to 0.35% of Sc element, 0.01% to 0.4% of B element, 0.3% to 1.0% of Mn element, 0.02% to 0.25% of Mo element, 0.01% to 0.2% of Zr element, 0.02% to 0.08% of Sr element, matrix element Al and unavoidable impurity elements.

[0121] In some embodiments, the aluminum alloy material includes an Al-Si eutectic phase, an AlB x Strengthening phase and AlSiMnSc strengthening phase.

[0122] By rationally designing the composition and content of each element in the aluminum alloy and utilizing the multiple synergistic effects between the elements, the prepared aluminum alloy material can have a special microstructure, thereby achieving good mechanical properties and excellent corrosion resistance. Under the above element composition, the aluminum alloy material can form α-Al matrix phase, Al-Si eutectic phase, AlB x Strengthening phase and AlSiMnSc strengthening phase can provide aluminum alloy materials with good mechanical properties, such as mechanical strength, strength, etc. The Si element can form an Al-Si eutectic phase with the α-Al matrix phase, which plays a strengthening role. The introduction of the rare earth element Sc can simultaneously improve the mechanical strength and corrosion resistance of aluminum alloy materials. It can produce a significant strengthening effect through limited solid solution and increased deformation resistance, and promote dislocation proliferation in the form of solid solution and formation of alloy phase. The alloy phase formed by the Sc element usually includes AlSiMnSc strengthening phase; in addition, some Sc elements can be dissolved in the matrix, increasing the self-corrosion potential, and some Sc elements can reduce the matrix-alloy phase potential difference and reduce the potential corrosion tendency. The B element can change the crystallization conditions of the aluminum alloy to increase the growth rate of the crystal nucleus, which can play a role in refining the grains. The solubility of the B element in the Al alloy is low, and it is easy to form AlB distributed near the eutectic structure. x Strengthening phase. The Mn element can form the AlSiMnSc strengthening phase, and it also helps to demold during the smelting process and make the precipitated phase uniformly distributed. The introduction of the Sr element can modify the Al-Si eutectic structure, and can improve mechanical properties such as mechanical strength and ductility. In addition, the Sr element can also help to improve the plastic workability of aluminum alloys, improve the mechanical properties of aluminum alloys, and reduce the homogenization time of ingots. The Mo element can be dissolved in aluminum crystals, which helps to promote the formation of a dense passivation film on aluminum alloys and increase corrosion resistance; the Zr element can hinder or inhibit the recrystallization process, thereby refining the casting structure. Through the overall design of the aforementioned element types and contents, good mechanical properties and excellent corrosion resistance can be better achieved with only a small amount of Mo and Zr elements.

[0123] In this application, unless otherwise specified, "matrix element" refers to the element that provides the matrix phase. When casting an alloy, an ingot of the matrix element is often used as the starting material, to which modifying elements are added, ultimately forming an alloy phase comprising multiple elements. In this application, the matrix element of the aluminum alloy material is Al.

[0124] In this application, unless otherwise specified, “inevitable impurities” refer to impurity elements that are not intentionally introduced but are inevitably brought into the preparation process.

[0125] In this application, the elemental composition, alloy phase, and alloy structure of aluminum alloy materials may be characterized and analyzed using methods including, but not limited to, X-ray diffraction (XRD), energy dispersive spectrometer (EDS), metallographic microscope, and scanning electron microscope (SEM). The operation methods and data analysis methods of these instruments are well known to those skilled in the art. Unless otherwise specified, the detection and analysis methods described in the Examples section below may be used, but are not limited thereto.

[0126] In some embodiments, AlB x The mass fraction of the strengthening phase in the aluminum alloy material may be less than or equal to 0.1% (corresponding to ≤0.1%), and may be optionally 0.05% to 0.1%. x The mass fraction of the strengthening phase in the aluminum alloy material can also be any of the following percentages, or a range consisting of any two of the following percentages: 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, etc.

[0127] In some embodiments, the mass fraction of the AlSiMnSc strengthening phase in the aluminum alloy material may be ≤0.2%, and may be 0.07% to 0.2%. The mass fraction of the AlSiMnSc strengthening phase in the aluminum alloy material may also be any of the following percentages, or a range consisting of any two of the following percentages: 0.07%, 0.08%, 0.09%, 0.1%, 0.12%, 0.14%, 0.15%, 0.16%, 0.18%, 0.2%, etc.

[0128] Based on any appropriate embodiment of the present application, further, in some embodiments, the aluminum alloy material satisfies one or more of the following characteristics (any numerical parameter in the following characteristics can also be selected from any appropriate numerical value or range in the context):

[0129] AlB x The mass fraction of the strengthening phase in the aluminum alloy material is ≤0.1%, and can be selected from 0.05% to 0.1%;

[0130] The mass fraction of the AlSiMnSc strengthening phase in the aluminum alloy material is ≤0.2%, and can be selected from 0.07% to 0.2%.

[0131] By regulating AlB x The mechanical strength of aluminum alloy materials can be adjusted by controlling the content of either or both of the AlSiMnSc strengthening phase and the AlB strengthening phase.x The content of strengthening phase is also beneficial to reduce the adverse effect of the relative corrosion resistance of the alloy. x Controlling the contents of the strengthening phase and the AlSiMnSc strengthening phase in the aluminum alloy material within the aforementioned range is more conducive to achieving both good mechanical properties and excellent corrosion resistance.

[0132] Based on any suitable embodiment of the present application, further, in some embodiments, the mass percentage of Si (silicon) element in the aluminum alloy material can be 8% to 11.5%, optionally 8.5% to 11.5%, and further optionally 8.5% to 11%. The mass percentage of Si element in the aluminum alloy material can also be any of the following percentages, or an interval consisting of any two of the following percentages: 8%, 8.5%, 9%, 9.5%, 10%, 10.5%, 11%, 11.5%, etc. The mass percentage of Si element in the aluminum alloy material can also be selected from any suitable range within the following ranges: 8% to 11%, 8% to 10.5%, 8.5% to 10.5%, 9% to 11%, 9% to 10.5%, 9% to 10%, etc.

[0133] Based on any suitable embodiment of the present application, further, in some embodiments, the mass percentage of the Sc (scandium) element in the aluminum alloy material can be 0.05% to 0.35%, optionally 0.1% to 0.35%, and further optionally 0.1% to 0.3%. The mass percentage of the Sc element in the aluminum alloy material can also be any of the following percentages, or an interval consisting of any two of the following percentages: 0.05%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, etc. The mass percentage of the Sc element in the aluminum alloy material can also be selected from any suitable range of the following ranges: 0.15% to 35%, 0.15% to 3%, 0.1% to 0.25%, 0.15% to 0.25%, etc.

[0134] Based on any suitable embodiment of the present application, further, in some embodiments, the mass percentage of the B (boron) element in the aluminum alloy material can be 0.01% to 0.4%, optionally 0.01% to 0.25%, and further optionally 0.01% to 0.1%. The mass percentage of the B element in the aluminum alloy material can also be any of the following percentages, or an interval consisting of any two of the following percentages: 0.01%, 0.015%, 0.02%, 0.025%, 0.03%, 0.035%, 0.04%, 0.05%, 0.06%, 0.08%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, etc. The mass percentage of B element in the aluminum alloy material can also be selected from any appropriate range among the following ranges: 0.01% to 0.06%, 0.01% to 0.05%, 0.01% to 0.025%, 0.02% to 0.25%, 0.02% to 0.2%, 0.02% to 0.1%, 0.02% to 0.08%, 0.02% to 0.06%, 0.02% to 0.05%, 0.02% to 0.025%, 0.05% to 0.25%, 0.05% to 0.4%, 0.05% to 0.1%, etc.

[0135] Based on any suitable embodiment of the present application, further, in some embodiments, the mass percentage of the Mn (manganese) element in the aluminum alloy material can be 0.3% to 1.0%, optionally 0.45% to 0.95%, and further optionally 0.45% to 0.70%. The mass percentage of the Mn element in the aluminum alloy material can also be any of the following percentages, or an interval consisting of any two of the following percentages: 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, 0.5%, 0.55%, 0.6%, 0.65%, 0.7%, 0.75%, 0.8%, 0.85%, 0.9%, 0.95%, 1.0%, etc.

[0136] Based on any suitable embodiment of the present application, further, in some embodiments, the aluminum alloy material satisfies one or more of the following characteristics (any numerical parameter in the following characteristics can also be selected from any suitable numerical value or range in the context):

[0137] The mass percentage of Si element in the aluminum alloy material is 8% to 11.5%, optionally 8.5% to 11.5%, and further optionally 8.5% to 11% (can also be selected from any appropriate content or range in the context);

[0138] The mass percentage of the Sc element in the aluminum alloy material is 0.05% to 0.35%, optionally 0.1% to 0.35%, and further optionally 0.1% to 0.3% (it can also be selected from any appropriate content or range in the context);

[0139] The mass percentage of element B in the aluminum alloy material is 0.01% to 0.4%, optionally 0.01% to 0.25%, and further optionally 0.01% to 0.1% (it can also be selected from any appropriate content or range in the context);

[0140] The mass percentage of the Mn element in the aluminum alloy material is 0.3% to 1.0%, optionally 0.45% to 0.95%, and further optionally 0.45% to 0.70% (it can also be selected from any appropriate content or range in the context).

[0141] In this application, the content of element X may be referred to as “X content”.

[0142] By regulating the contents of Si, Sc, B and Mn elements within the aforementioned range, the contents of the Al-Si eutectic phase, AlBx strengthening phase and AlSiMnSc strengthening phase can be regulated, which is more conducive to taking into account both mechanical properties and corrosion resistance, and achieving good mechanical properties and excellent corrosion resistance at the same time.

[0143] The appearance of the Al-Si eutectic phase can be achieved by regulating the Si content below the eutectic point of the Si element (about 11.7%), which is beneficial to suppressing the generation of primary silicon that is detrimental to corrosion performance.

[0144] By controlling the Sc content within the aforementioned range, it is beneficial to improve the mechanical properties and corrosion resistance while taking the cost into consideration.

[0145] By controlling the B content within the above range, it is possible to effectively refine grains and AlB x While strengthening the phase interaction, it also better inhibits AlB x The adverse effects of alloy phase corrosion.

[0146] The addition of Mn provides a reinforcing effect, primarily by dissolving in the Al matrix and increasing its strength through lattice distortion. Controlling the Mn content can adjust the content of the AlSiMnSc strengthening phase and the MnAl6 alloy phase, as well as modulating the demolding process and promoting a uniform distribution of the precipitated phase. By controlling the Mn content within the aforementioned range, the mechanical properties of the aluminum alloy are further enhanced.

[0147] Based on any suitable embodiment of the present application, further, in some embodiments, the aluminum alloy material includes a MnAl6 alloy phase; optionally, the mass fraction of the MnAl6 alloy phase in the aluminum alloy material is 0.55% to 1.25%, and further optionally 0.45% to 1.3%. The mass fraction of the MnAl6 alloy phase in the aluminum alloy material can also be any of the following percentages, or a range consisting of any two of the following percentages: 0.45%, 0.5%, 0.55%, 0.6%, 0.65%, 0.7%, 0.75%, 0.8%, 0.85%, 0.9%, 0.95%, 1%, 1.05%, 1.1%, 1.15%, 1.2%, 1.25%, 1.3%, etc.

[0148] The MnAl6 alloy phase can play a supplementary strengthening role. By adjusting the content of the MnAl6 alloy phase within the aforementioned range, it is beneficial to better play the reinforcing role. The content of the MnAl6 alloy phase can be adjusted by adjusting the content of the Mn element. Within a certain range of the Mn element content, the content of the MnAl6 alloy phase in the aluminum alloy material can be increased by increasing the Mn element content.

[0149] Based on any suitable embodiment of the present application, in some embodiments, the mass percentage of the Mo (molybdenum) element in the aluminum alloy material can be 0.02% to 0.25%, optionally 0.04% to 0.2%, and further optionally 0.05% to 0.1%. The mass percentage of the Mo element in the aluminum alloy material can also be any of the following percentages, or an interval consisting of any two of the following percentages: 0.02%, 0.04%, 0.05%, 0.06%, 0.08%, 0.1%, 0.12%, 0.15%, 0.16%, 0.18%, 0.2%, 0.24%, 0.25%, etc. The mass percentage of Mo element in the aluminum alloy material can also be selected from any appropriate range among the following ranges: 0.02% to 0.2%, 0.02% to 0.15%, 0.02% to 0.1%, 0.02% to 0.08%, 0.04% to 0.2%, 0.04% to 0.15%, 0.04% to 0.1%, 0.04% to 0.08%, 0.05% to 0.25%, 0.05% to 0.2%, 0.05% to 0.15%, 0.05% to 0.1%, 0.05% to 0.08%, etc.

[0150] Based on any suitable embodiment of the present application, in some embodiments, the mass percentage of the Zr (zirconium) element in the aluminum alloy material can be 0.01% to 0.2%, optionally 0.01% to 0.15%, and further optionally 0.05% to 0.15%. The mass percentage of the Zr element in the aluminum alloy material can also be any of the following percentages, or an interval consisting of any two of the following percentages: 0.01%, 0.02%, 0.04%, 0.05%, 0.06%, 0.08%, 0.1%, 0.12%, 0.15%, 0.16%, 0.18%, 0.2%, etc. The mass percentage of Zr element in the aluminum alloy material can also be selected from any appropriate range among the following ranges: 0.01% to 0.1%, 0.01% to 0.08%, 0.02% to 0.2%, 0.02% to 0.15%, 0.02% to 0.1%, 0.02% to 0.08%, 0.04% to 0.2%, 0.04% to 0.15%, 0.04% to 0.1%, 0.04% to 0.08%, 0.05% to 0.2%, 0.05% to 0.15%, 0.05% to 0.1%, 0.05% to 0.08%, etc.

[0151] Based on any appropriate embodiment of the present application, further, in some embodiments, the aluminum alloy material satisfies one or more of the following characteristics (any numerical parameter in the following characteristics can also be selected from any appropriate numerical value or range in the context):

[0152] The mass percentage of Mo element in the aluminum alloy material is 0.02% to 0.25%, optionally 0.04% to 0.20%, and further optionally 0.05% to 0.1% (can also be selected from any appropriate content or range in the context);

[0153] The mass percentage of the Zr element in the aluminum alloy material is 0.01% to 0.2%, optionally 0.01% to 0.15%, and further optionally 0.05% to 0.15% (it can also be selected from any appropriate content or range in the context).

[0154] Mo dissolves in aluminum crystals, promoting the formation of a dense passivation film on aluminum alloys and enhancing corrosion resistance. Zr hinders or inhibits recrystallization, thereby refining the casting structure. By controlling the contents of both elements within the aforementioned ranges, based on the aforementioned elemental composition and alloy phase design, aluminum alloy materials can achieve both good mechanical properties and excellent corrosion resistance.

[0155] Based on any suitable embodiment of the present application, further, in some embodiments, the mass percentage of the Sr (strontium) element in the aluminum alloy material can be 0.02% to 0.08% (i.e., 200 to 800 ppm), optionally 0.02% to 0.06%, and further optionally 0.02% to 0.05%. The mass percentage of the Sr element in the aluminum alloy material can also be any of the following values, or an interval consisting of any two of the following values: 200ppm, 250ppm, 300ppm, 350ppm, 400ppm, 450ppm, 500ppm, 550ppm, 600ppm, 650ppm, 700ppm, 750ppm, 800ppm, etc. The mass percentage of the Sr element in the aluminum alloy material can also be selected from any suitable range within the following ranges: 200ppm to 500ppm, 300ppm to 500ppm, etc.

[0156] In this application, 1 ppm means one part per million, 1 ppm=0.0001%, for example, 200 ppm=0.02%, 800 ppm=0.08%.

[0157] By adjusting the Sr content, the modification effect of Sr on the Al-Si eutectic structure can be adjusted. By controlling the Sr content within a more appropriate range, it is more conducive to optimizing the mechanical properties of aluminum alloy materials.

[0158] Based on any suitable embodiment of the present application, further, in some embodiments, the aluminum alloy material includes a matrix element Al, and the aluminum alloy material satisfies one or more of the following characteristics (any numerical parameter in the following characteristics can also be selected from any suitable value or range in the context):

[0159] The mass percentage of Si element in aluminum alloy material is 8% to 11.5%;

[0160] The mass percentage of Sc element in the aluminum alloy material is 0.05% to 0.35%;

[0161] The mass percentage of B element in the aluminum alloy material is 0.01% to 0.4%.

[0162] The mass percentage of Mn element in aluminum alloy material is 0.3% to 1.0%;

[0163] The mass percentage of Mo element in aluminum alloy material is 0.02% to 0.25%;

[0164] The mass percentage of Zr element in aluminum alloy material is 0.01% to 0.2%;

[0165] The mass percentage of Sr element in the aluminum alloy material is 0.02% to 0.08%.

[0166] Based on any suitable embodiment of the present application, further, in some embodiments, the aluminum alloy material includes a matrix element Al, and the aluminum alloy material satisfies one or more of the following characteristics (any numerical parameter in the following characteristics can also be selected from any suitable value or range in the context):

[0167] The mass percentage of Si element in aluminum alloy material is 8.5% to 11.5%;

[0168] The mass percentage of Sc element in aluminum alloy material is 0.1% to 0.3%;

[0169] The mass percentage of element B in the aluminum alloy material is 0.01% to 0.25%.

[0170] The mass percentage of Mn element in aluminum alloy material is 0.45% to 0.95%;

[0171] The mass percentage of Mo element in aluminum alloy material is 0.04% to 0.2%;

[0172] The mass percentage of Zr element in aluminum alloy material is 0.01% to 0.15%;

[0173] The mass percentage of Sr element in the aluminum alloy material is 0.02% to 0.06%.

[0174] Based on any suitable embodiment of the present application, further, in some embodiments, the aluminum alloy material includes a matrix element Al, and the aluminum alloy material satisfies one or more of the following characteristics (any numerical parameter in the following characteristics can also be selected from any suitable value or range in the context):

[0175] The mass percentage of Si element in aluminum alloy material is 8.5% to 11%;

[0176] The mass percentage of Sc element in aluminum alloy material is 0.1% to 0.3%;

[0177] The mass percentage of B element in the aluminum alloy material is 0.01% to 0.1%.

[0178] The mass percentage of Mn element in aluminum alloy material is 0.45% to 0.70%;

[0179] The mass percentage of Mo element in aluminum alloy material is 0.05% to 0.1%;

[0180] The mass percentage of Zr element in aluminum alloy material is 0.05% to 0.15%;

[0181] The mass percentage of Sr element in the aluminum alloy material is 0.02% to 0.05%.

[0182] Based on any suitable embodiment of the present application, further, in some embodiments, the aluminum alloy material includes, by mass percentage, 8.5% to 11.5% Si, 0.1% to 0.35% Sc, 0.01% to 0.25% B, 0.45% to 0.95% Mn, 0.05% to 0.2% Mo, 0.01% to 0.15% Zr, 0.02% to 0.06% Sr, matrix element Al, and unavoidable impurity elements. The content of any of the above elements can also refer to any suitable range or value in the context.

[0183] Based on any suitable embodiment of the present application, further, in some embodiments, the aluminum alloy material includes, by mass percentage, 8.5% to 11% Si, 0.1% to 0.3% Sc, 0.01% to 0.1% B, 0.45% to 0.70% Mn, 0.05% to 0.1% Mo, 0.05% to 0.15% Zr, 0.02% to 0.05% Sr, matrix element Al, and unavoidable impurity elements. The content of any of the above elements can also refer to any suitable range or value in the context.

[0184] Based on any suitable embodiment of the present application, further, in some embodiments, the aluminum alloy material includes, by mass percentage, 8% to 11.5% Si, 0.05% to 0.35% Sc, 0.01% to 0.4% B, 0.3% to 1.0% Mn, 0.05% to 0.25% Mo, 0.01% to 0.2% Zr, 0.02% to 0.08% Sr, unavoidable impurity elements, and the balance Al. The content of any of the above elements may also refer to any suitable range or value in the context.

[0185] Based on any suitable embodiment of the present application, further, in some embodiments, the aluminum alloy material includes, by mass percentage, 8% to 11.5% Si, 0.05% to 0.35% Sc, 0.05% to 0.4% B, 0.3% to 1.0% Mn, 0.05% to 0.25% Mo, 0.01% to 0.2% Zr, 0.02% to 0.08% Sr, unavoidable impurity elements, and the balance Al. The content of any of the above elements may also refer to any suitable range or value in the context.

[0186] By adjusting the types and contents of various elements in the aluminum alloy material, the aluminum alloy material can obtain good mechanical properties and excellent corrosion resistance within a variety of content ranges.

[0187] Based on any appropriate embodiment of the present application, further, in some embodiments, the unavoidable impurity elements include Fe.

[0188] Based on any appropriate embodiment of the present application, further, in some embodiments, the mass percentage of Fe (iron) element in the aluminum alloy material is ≤0.7%, and can be optionally <0.7%.

[0189] Based on any appropriate embodiment of the present application, further, in some embodiments, the mass percentage of unavoidable impurity elements in the aluminum alloy material is ≤0.7%, and can be optionally <0.7%.

[0190] Based on any suitable embodiment of the present application, further, in some embodiments, the aluminum alloy material includes an AlSiMnFe phase, and optionally, the mass fraction of the AlSiMnFe phase in the aluminum alloy material is ≤0.2%, and further optionally ≤0.1%. The mass fraction of the AlSiMnFe phase in the aluminum alloy material can also be any of the following percentages, less than or equal to any of the following percentages, or a range consisting of any two of the following percentages: 0.01%, 0.02%, 0.05%, 0.06%, 0.08%, 0.1%, 0.12%, 0.15%, 0.16%, 0.18%, 0.2%, etc. The mass fraction of the AlSiMnFe phase in the aluminum alloy material can also be selected from any suitable range among the following ranges: ≤0.15%, 0.01% to 0.2%, 0.01% to 0.15%, 0.01% to 0.1%, etc.

[0191] Based on any suitable embodiment of the present application, further, in some embodiments, the aluminum alloy material includes an AlSiMnFe / Sc alloy phase; optionally, the mass fraction of the AlSiMnFe / Sc alloy phase in the aluminum alloy material is ≤0.2%, and can be 0.07% to 0.2%. The mass fraction of the AlSiMnFe / Sc alloy phase in the aluminum alloy material can also be any of the following percentages, less than or equal to any of the following percentages, or a range consisting of any two of the following percentages: 0.07%, 0.08%, 0.1%, 0.12%, 0.15%, 0.16%, 0.18%, 0.2%, etc.

[0192] Based on any appropriate embodiment of the present application, further, in some embodiments, the aluminum alloy material satisfies one or more of the following characteristics (any numerical parameter in the following characteristics can also be selected from any appropriate numerical value or range in the context):

[0193] The mass percentage of Fe in the aluminum alloy material is ≤0.7%. Optionally, the mass percentage of unavoidable impurity elements in the aluminum alloy material is <0.7% (which can also be selected from any appropriate content or range in the context);

[0194] The aluminum alloy material includes an AlSiMnFe phase. Optionally, the mass fraction of the AlSiMnFe phase in the aluminum alloy material is ≤0.2%, further optionally ≤0.1% (can also be selected from any appropriate content or range in the context);

[0195] The aluminum alloy material includes an AlSiMnFe / Sc alloy phase; optionally, the mass fraction of the AlSiMnFe / Sc alloy phase in the aluminum alloy material is ≤0.2%, optionally 0.07% to 0.2% (can also be selected from any appropriate content or range in the context).

[0196] During the casting process of aluminum alloys, it is often inevitable that Fe impurities will be present in the formed aluminum alloy. A small amount of Fe element (such as Fe content ≤ 0.7wt%) helps to demold during the casting process. However, when the Fe content is high, it is easy to reduce the corrosion resistance of the aluminum alloy material. Fe impurities can form needle-shaped AlSiMnFe phases, which have a certain strengthening effect. However, due to the large contact area between the AlSiMnFe phase and the α-Al matrix and the large potential difference, local galvanic corrosion may occur. By controlling the Fe content within a lower content range, it is helpful to reduce the adverse effects of Fe on corrosion resistance.

[0197] In addition, the introduction of Sc element can transform a part of the needle-like AlSiMnFe phase into a fine, multi-branched AlSiMnFe / Sc alloy phase, reducing the damage of the needle-like AlSiMnFe phase to the corrosion resistance.

[0198] Based on any suitable embodiment of the present application, further, in some embodiments, the mass percentage of the Mg (magnesium) element in the aluminum alloy material is ≤0.1%, optionally ≤0.01%, and further optionally 0%. The mass percentage of the Mg element in the aluminum alloy material can also be any of the following percentages, less than or equal to any of the following percentages, or a range consisting of any two of the following percentages: 0.01%, 0.02%, 0.05%, 0.06%, 0.08%, etc.

[0199] Based on any suitable embodiment of the present application, further, in some embodiments, the mass percentage of the Zn (zinc) element in the aluminum alloy material is ≤0.1%, optionally ≤0.01%, and further optionally 0%. The mass percentage of the Zn element in the aluminum alloy material can also be any of the following percentages, less than or equal to any of the following percentages, or a range consisting of any two of the following percentages: 0.01%, 0.02%, 0.05%, 0.06%, 0.08%, etc.

[0200] Based on any suitable embodiment of the present application, further, in some embodiments, the mass percentage of the Cu (copper) element in the aluminum alloy material is ≤0.01%, and can be 0%. The mass percentage of the Cu element in the aluminum alloy material can also be any of the following percentages, less than or equal to any of the following percentages, or a range consisting of any two of the following percentages: 0.005%, 0.006%, 0.008%, 0.01%, etc.

[0201] Based on any appropriate embodiment of the present application, further, in some embodiments, the aluminum alloy material satisfies one or more of the following characteristics (any numerical parameter in the following characteristics can also be selected from any appropriate numerical value or range in the context):

[0202] The mass percentage of Mg element in the aluminum alloy material is ≤0.1%, optionally ≤0.01%, and further optionally 0% (it can also be selected from any appropriate content or range in the context);

[0203] The mass percentage of Zn element in the aluminum alloy material is ≤0.1%, optionally ≤0.01%, and further optionally 0% (can also be selected from any appropriate content or range in the context);

[0204] The mass percentage of Cu element in the aluminum alloy material is ≤0.01%, and may be selected as 0% (it may also be selected from any appropriate content or range in the context).

[0205] In some known aluminum alloy materials, one or more of Mg, Zn, and Cu are often added to achieve a strengthening effect. The aluminum alloy material provided in the first aspect can achieve good mechanical properties and excellent corrosion resistance while limiting the Mg, Zn, and Cu contents to relatively low levels.

[0206] In some embodiments, by rationally designing the element composition and element content, the aluminum alloy material has a microstructure as shown in FIG1 : mainly composed of primary α-Al crystals and Al-Si eutectic structures, in addition to alloy phases such as MnAl6 and AlSiMnFe / Sc.

[0207] In yet another aspect of the present application, a method for preparing the aluminum alloy material described in the first aspect of the present application is provided.

[0208] In some embodiments, a method for preparing an aluminum alloy material is provided, comprising the following steps:

[0209] S100 (melting): heating and melting the aluminum ingot, adding ingredients determined according to the nominal composition of the aluminum alloy material in the form of a master alloy, performing melting and refining and slagging to prepare a refined melt;

[0210] S200 (molding): casting the refined melt to obtain an ingot;

[0211] S300 (heat treatment): The ingot is heat treated and cooled to obtain an aluminum alloy material.

[0212] In this application, unless otherwise specified, "nominal composition" refers to the theoretical value or design value of the target composition.

[0213] In step S100, a refined melt is prepared by smelting, and the obtained refined melt is also referred to as an aluminum alloy refined melt.

[0214] In the present application, "melting" has a well-known meaning in the art, which refers to the operation of heating and melting solid metal and performing tempering, and is one of the processes for casting alloys. Generally, a smelting furnace is required in the smelting process, in which other components required for preparing the alloy are melted, and the material is smelted into the required alloy through operations such as slagging and refining. Other components required for preparing the alloy may include metal ingots that provide matrix elements and necessary alloy components. In the present application, before casting and molding, it is necessary to first smelt to obtain a refined melt containing the required components of the aluminum alloy material. When the nominal composition of the aluminum alloy material is determined, those skilled in the art can reasonably determine the implementation method of the smelting.

[0215] The alloying elements can be added in the form of a master alloy, but are not limited thereto. Once the nominal composition of the aluminum alloy material is determined, those skilled in the art can select the appropriate addition temperature and timing based on the properties of each alloying element (e.g., melting point) to ensure that the material remains in a molten state throughout the entire process from heating and melting the aluminum ingot to producing the refined melt.

[0216] The addition amount of some elements may need to take into account the burn-out rate.

[0217] In some embodiments, the alloying elements are added as follows: AlSi2O, AlMn1O, AlMo6O, AlZr1O, AlSr1O, AlSc2, AlB3, and Al. The numbers represent the atomic ratios (or atomic ratios) between the elements, and different numbers correspond to different alloy grades. Those skilled in the art will understand the meaning of the corresponding grades.

[0218] In some embodiments, the ingredients determined according to the nominal composition of the aluminum alloy material may include AlSi20, AlMn10, AlMo60, AlZr10, AlSr10, AlSc2 and AlB3. In this case, the alloying elements except aluminum are added in the form of intermediate alloys.

[0219] In this application, unless otherwise specified, "melt refining" refers to refining the material in a molten state so that the elements in the material diffuse with each other and mix fully to form a uniform liquid melt.

[0220] Without limitation, melt refining includes refining.

[0221] In this application, "refining" has a well-known meaning in the art and refers to the step of obtaining a high-purity alloy by removing impurities and impure substances. A suitable refining method can be selected according to the composition characteristics of the aluminum alloy material. In a non-limiting manner, the refining purpose can be achieved by adding a refining agent. The refining agent used in this application can be a commonly used refining agent for casting aluminum alloys, such as a high-efficiency refining agent (non-toxic refining agent), a degassing refining agent, etc.

[0222] In this application, "slag skimming" has a well-known meaning in the art and refers to the step of removing slag from the melt during the smelting process. During the smelting and refining process, slag may float on the surface of the melt, which can be removed by skimming. Slag skimming can be performed once or multiple times.

[0223] In step S200, the refined solution obtained by smelting is cast into an ingot, which is also referred to as an aluminum alloy ingot.

[0224] After casting, the resulting ingot acquires a predetermined shape and size. The ingot may have a predetermined shape and size. The predetermined shape and size may be determined based on experimental test samples or actual needs. The shape and size of the ingot can be controlled by the shape and size of the mold used during casting.

[0225] In step S300, the target aluminum alloy material is prepared by heat treating the ingot obtained by casting.

[0226] The heat treatment can be achieved by keeping the ingot at a certain temperature and can be terminated by cooling.

[0227] In the step of heat treating the ingot, the heat treatment can be carried out in an insulation manner. The appropriate insulation temperature (also recorded as annealing temperature) and insulation time can be selected according to the size of the ingot to achieve a good annealing effect. Generally, the annealing insulation temperature can be slightly lower than the melting point temperature. As a non-limiting example, it can be 70% to 80% of the melting point temperature. The larger the ingot, the longer the required heat treatment insulation time is. A longer insulation time helps to improve the annealing effect. The insulation time can be controlled within a certain time range so as to achieve a good annealing effect while also avoiding overburning and coarse grains as much as possible. Diligent slagging during the insulation process helps to obtain a well-formed ingot. The appropriate insulation time can be selected according to the size of the ingot. Typically, the holding time during heat treatment is at least 0.5 h, and can be any of the following durations, or a range consisting of any two of the following durations: 1 h, 2 h, 3 h, 5 h, 6 h, 8 h, 10 h, 15 h, 20 h, 25 h, 30 h, 35 h, 40 h, 45 h, 48 h, 50 h, etc. Taking an ingot with dimensions of 20 mm × 35 mm × 10 mm as an example, the annealing time can be 1.5 h to 3 h, for example, 1.5 h, 2 h, 2.5 h, 3 h, etc.

[0228] Those skilled in the art can select appropriate process parameters to effectively reduce or eliminate the intragranular segregation of elements in the aluminum alloy to achieve the purpose of homogenization and realize the purpose of improving the comprehensive performance of the mechanical properties and corrosion resistance of the aluminum alloy material.

[0229] In some embodiments, the ingot is heat treated, and the cooling step includes keeping the ingot warm and cooling it.

[0230] In some embodiments, during the step of holding and cooling the ingot, the holding temperature may be 450°C to 620°C, and further may be 540°C to 620°C. The holding time may be determined by referring to the above method. In some embodiments, the holding time may be 1 hour to 3 hours, and further may be 1 hour to 2 hours, such as 1 hour, 1.5 hours, 2 hours, 2.5 hours, etc. In other embodiments, the holding time may be 36 hours to 48 hours, and further may be 36 hours to 45 hours, such as 36 hours, 40 hours, 45 hours, 48 ​​hours, etc.

[0231] In some embodiments, the ingot is heat treated, and in the cooling step, the ingot is cooled to 20°C to 30°C.

[0232] Without limitation, the cooling medium may be an inert gas, oil, air cooling, furnace cooling, or the like.

[0233] In some embodiments, step S100 includes step S110, step S120, and step S130.

[0234] In some embodiments, step S110 includes: heating an aluminum ingot to melt, adding a material containing Mn and smelting to obtain a first melt.

[0235] In some embodiments, step S120 includes: cooling the first melt, adding ingredients containing Si, Mo, Zr, Sc and B to the cooled and molten first melt for smelting to obtain a second melt.

[0236] In some embodiments, step S130 includes: skimming the second melt, adding a refining agent, and adding ingredients containing the Sr element for refining to obtain a refined melt.

[0237] It should be noted that the slagging in step S130 can be performed while step S110 or step S120 is being implemented.

[0238] The Sr element can be added at the end, which is more conducive to the modification effect of the Sr element on the alloy phase.

[0239] In some embodiments, a method for preparing an aluminum alloy material is provided, comprising the following steps:

[0240] S110: heating the aluminum ingot until it is melted, adding a material containing a Mn element and smelting it to obtain a first melt;

[0241] S120: Cooling the first melt, adding ingredients including Si, Mo, Zr, Sc, and B to the cooled and molten first melt, and smelting the mixture to obtain a second melt;

[0242] S130: Deslagging the second melt, adding a refining agent, and adding ingredients containing the Sr element for refining to obtain a refined melt;

[0243] S200: casting the refined melt to obtain an ingot;

[0244] S300: heat-treating the ingot and cooling it to obtain an aluminum alloy material.

[0245] In this application, a material including an X element may be referred to as an "X material." As one example, a material including an Mn element may be referred to as a Mn material.

[0246] Generally, the amount of each ingredient added can be measured based on the elemental composition of the aluminum alloy material and the burn-out rate of each element.

[0247] In the process of preparing aluminum alloy materials, after the matrix elements are melted, the ingredients containing Mn elements are first added for smelting, which helps the demoulding process and can reduce the introduction of Fe elements in the mold.

[0248] In some embodiments, the aluminum ingot is heated to 740° C. to 760° C. in the step of melting. Non-limiting examples of the heating temperature include 740° C., 750° C., 760° C., and the like.

[0249] In some embodiments, after the step of heating the aluminum ingot to melt and before the step of adding the ingredients containing the Mn element for smelting, a heat preservation step is further included, and the heat preservation temperature can be 740°C to 760°C.

[0250] In some embodiments, in the step of adding the ingredients containing the Mn element and performing smelting, the smelting temperature may be 740° C. to 760° C.

[0251] In some embodiments, after the step of cooling the first melt, before the step of adding ingredients containing Si, Mo, Zr, Sc and B elements to the cooled molten first melt for smelting, a heat preservation step may be included, and the heat preservation temperature may be 710°C to 730°C.

[0252] In some embodiments, a method for preparing an aluminum alloy material is provided, comprising the following steps:

[0253] S110: heating the aluminum ingot to 740° C. to 760° C. and melting the ingot, adding a material containing a Mn element and smelting the ingot to obtain a first melt;

[0254] S120: Cooling the first melt to 710° C. to 730° C., adding ingredients including Si, Mo, Zr, Sc, and B to the first melt for smelting to obtain a second melt;

[0255] S130: Skimming the second melt, adding a refining agent, and adding ingredients containing the Sr element for refining to obtain a refined melt;

[0256] S200: casting the refined melt to obtain an ingot;

[0257] S300: The ingot is kept at 450°C to 560°C (optionally 540°C to 560°C) for a suitable time (the suitable holding time is selected according to the size of the ingot, such as 36h to 48h, or 1h to 2h), and cooled (water cooling to room temperature) to obtain an aluminum alloy material.

[0258] The ingredient containing the Mn element may be an aluminum-manganese master alloy.

[0259] In some embodiments, a method for preparing an aluminum alloy material is provided, comprising the following steps:

[0260] S100: adding a pure aluminum ingot and heating it to 740°C to 760°C, keeping it warm and melting it, and then adding a material containing the Mn element in the form of an aluminum-manganese master alloy; after the material containing the Mn element is melted, cooling it to 710°C to 730°C, adding an alloying element material containing the Si element, the Mo element, the Zr element, the Sc element, and the B element to melt it; after the alloying element material is melted, standing it to skim off the slag, adding a refining agent, and after skimming off the slag, adding a material containing the Sr element, and casting it to obtain an ingot; optionally, the Mn element, the Si element, the Mo element, the Zr element, the Sc element, and the B element are respectively introduced in the form and content of corresponding master alloys.

[0261] S200: The ingot is placed at 450°C to 620°C (optionally 540°C to 620°C) for a suitable holding time (the appropriate holding time is selected according to the size of the ingot, such as holding for 36h to 45h, or for 1h to 2h), and then water-cooled to room temperature (such as 20°C to 30°C) to obtain an aluminum alloy material. The obtained aluminum alloy material can be used as an aluminum alloy material for a battery case, including but not limited to an aluminum alloy material for a lithium battery case.

[0262] In a second aspect of the present application, an aluminum alloy structural part is provided, which is a formed body of the aluminum alloy material described in the first aspect of the present application.

[0263] In this application, unless otherwise specified, a "formed body of an aluminum alloy material" refers to a solid object composed of the aluminum alloy material and having a predetermined shape and size. The shape and size of the aluminum alloy material can be defined by a mold during its production, thereby forming a solid object of predetermined shape and size.

[0264] The aluminum alloy structural member formed from the aluminum alloy material described in the first aspect of the present application may have good mechanical properties and excellent corrosion resistance, and can be used as an aluminum alloy structural member in a battery case, which can effectively extend the service life of the battery case.

[0265] In a third aspect of the present application, a method for preparing an aluminum alloy structural part is provided, which can be prepared using the aforementioned method for preparing the aluminum alloy material.

[0266] In some embodiments, a method for preparing an aluminum alloy structural part is provided, comprising the following steps:

[0267] S100 (melting): heating and melting the aluminum ingot, adding ingredients determined according to the nominal composition of the aluminum alloy material in the form of a master alloy, performing melting and refining and slagging to prepare an aluminum alloy refined melt;

[0268] S200 (molding): casting the aluminum alloy refined melt to prepare an aluminum alloy ingot;

[0269] S300 (heat treatment): The aluminum alloy ingot is heat treated and cooled to produce aluminum alloy structural parts.

[0270] In step S100 , the aluminum alloy material may be the aluminum alloy material described in the first aspect of the present application.

[0271] The aluminum alloy ingot prepared in step S200 has a certain shape and size. After heat treatment and cooling in step S300, the obtained aluminum alloy material also has a certain shape and size. Therefore, an aluminum alloy structural part can be obtained while obtaining the aluminum alloy material.

[0272] The implementation of step S100, step S200 and step S300 may also refer to the aforementioned method for preparing the aluminum alloy material, and may also refer to the following implementation manner or examples.

[0273] The aluminum alloy structural part can be produced by using aluminum ingots to provide a matrix element, supplemented with corresponding alloying elements, and then undergoing smelting, refining, slagging, casting, heat treatment, and cooling. The shape and size of the aluminum alloy structural part can be controlled by selecting a mold of a corresponding shape and size during the casting step. It is understood that the shape and size of the cooled structural part can also be adjusted to obtain an aluminum alloy structural part of a target shape and size, for example, by using treatments including but not limited to sandblasting and polishing.

[0274] In a fourth aspect of the present application, a battery case is provided, which may meet at least one of the following characteristics:

[0275] At least a portion of the structural members in the battery case comprises the aluminum alloy material described in the first aspect of the present application;

[0276] The battery box includes the aluminum alloy structural member described in the second aspect of the present application; and

[0277] The battery case includes an aluminum alloy structural part prepared by the method for preparing an aluminum alloy structural part described in the third aspect of the present application.

[0278] The battery case provides protection for the battery cells inside. On the one hand, the battery case needs to have good mechanical strength to reduce the damage to the battery cells when they are hit. On the other hand, the battery case is susceptible to galvanic corrosion during storage and battery cycling. Therefore, the battery case also needs to have a certain degree of corrosion resistance. The battery case made of the aforementioned aluminum alloy material or aluminum alloy structural parts can meet the requirements of both mechanical properties and corrosion resistance.

[0279] Without limitation, the portions of the battery case containing the aforementioned aluminum alloy material may include one or more of, but are not limited to, the bottom plate, the panel, and the bracket. The portions of the battery case containing the aforementioned aluminum alloy material may be integrally formed or fixedly connected by suitable means, such as seamless welding, to better match the desired shape and size.

[0280] Based on any suitable embodiment of the present application, further, in some embodiments, the battery case includes a lithium battery case.

[0281] The aforementioned aluminum alloy material can be applied to lithium battery cases, but is not limited thereto.

[0282] In a fifth aspect of the present application, a battery system is provided, which includes the battery case described in the fourth aspect of the present application and a battery cell located inside the described battery case.

[0283] Based on any suitable embodiment of the present application, further, in some embodiments, the battery cell includes a liquid electrolyte.

[0284] In the sixth aspect of the present application, an electrical device is provided, which includes the aluminum alloy material described in the first aspect of the present application, the aluminum alloy structural part described in the second aspect of the present application, the aluminum alloy structural part obtained by the preparation method of the aluminum alloy structural part described in the third aspect of the present application, the battery case described in the fourth aspect of the present application, and at least one of the battery system described in the fifth aspect of the present application.

[0285] In the seventh aspect of the present application, there is provided the use of the aluminum alloy material described in the first aspect of the present application in the preparation of at least one of an aluminum alloy structural member, a battery case, a battery system and an electrical device.

[0286] By using the aforementioned aluminum alloy materials, the aforementioned aluminum alloy structural parts, or the battery case including the aforementioned aluminum alloy materials or aluminum alloy structural parts in one or more of the battery system and the electrical device, it is beneficial to improve the reliability and life of the battery system and the electrical device. It can not only reduce the degree of damage to the battery when it is hit, but also improve the corrosion resistance of the battery case, including but not limited to improving the resistance to galvanic corrosion.

[0287] In this application, unless otherwise specified, a "battery cell" refers to a basic unit that can realize the mutual conversion of chemical energy and electrical energy.

[0288] In some embodiments, the battery cell is a fuel cell, the corresponding battery housing is a fuel cell housing, and the corresponding battery system is a fuel cell system.

[0289] In this application, unless otherwise specified, a "fuel cell housing" refers to a housing containing a fuel cell. In this application, unless otherwise specified, "fuel cell" has the commonly known meaning in the art, meaning a chemical device that directly converts the chemical energy of a fuel into electrical energy; and a "fuel cell" refers to a cell that directly converts the chemical energy of a fuel into electrical energy.

[0290] In some embodiments, the battery cells are lithium batteries, the corresponding battery housing is a lithium battery housing, and the corresponding battery system is a lithium battery system. In this case, the active ions in the battery cells include lithium ions. The lithium battery may be a lithium-ion secondary battery.

[0291] In this application, unless otherwise specified, a "lithium battery case" refers to a battery case containing a lithium battery cell. In this application, unless otherwise specified, "lithium battery" has the commonly known meaning in the art, referring to a type of battery whose active ions include lithium ions; and "lithium battery cell" refers to a battery cell whose active ions include lithium ions.

[0292] In some embodiments, the battery cell is a secondary battery, the corresponding battery case is a secondary battery case, and the corresponding battery system is a secondary battery system. In some embodiments, the battery cell may include a positive electrode sheet, a negative electrode sheet, and an electrolyte. During the battery charge and discharge process, active ions are embedded and released back and forth between the positive electrode sheet and the negative electrode sheet. The electrolyte plays a role in conducting active ions between the positive electrode sheet and the negative electrode sheet. In some embodiments, the positive electrode sheet, the negative electrode sheet, and the separator can be made into an electrode assembly by a winding process or a lamination process.

[0293] When the battery cells in the battery system include liquid electrolytes, higher corrosion resistance is required for the battery case. The battery system and electrical device provided above are more likely to meet storage and usage requirements.

[0294] The battery case includes at least one battery cell. The battery case may include one or more battery cells. The present application does not specifically limit the shape of the battery cells, which may be cylindrical, square, or any other shape. In some embodiments, the battery cells may include an outer packaging.

[0295] The outer packaging of the battery cell can be used to encapsulate the above-mentioned electrode assembly and electrolyte, but is not limited thereto.

[0296] In some embodiments, the outer packaging of the battery cell may be a hard shell, such as a hard plastic shell, an aluminum shell, or a steel shell. Alternatively, the outer packaging of the battery cell may be a soft shell, such as a pouch-type soft shell. The soft shell may be made of plastic. Non-limiting examples of plastic include one or more of polypropylene, polybutylene terephthalate, and polybutylene succinate.

[0297] In some embodiments, the outer packaging may include a housing and a cover. The housing may include a bottom plate and side plates connected to the bottom plate, with the bottom plate and side plates enclosing a receiving cavity. The housing may have an opening communicating with the receiving cavity, and the cover may be positioned over the opening to seal the receiving cavity.

[0298] Without limitation, the aforementioned electrode assembly may be encapsulated in a housing cavity; in some embodiments, a liquid electrolyte may be impregnated in the electrode assembly; the number of electrode assemblies contained in a battery cell may be one or more, and those skilled in the art may select according to actual needs.

[0299] The battery system may be a battery module 4 or a battery pack 1 .

[0300] The battery module 4 includes at least one battery cell 5. The number of battery cells 5 included in the battery module 4 can be one or more, and those skilled in the art can select a suitable number of battery cells according to the application and capacity of the battery module.

[0301] Figure 9 shows an example battery module 4. Referring to Figure 9 , in the battery module 4, multiple battery cells 5 may be arranged sequentially along the length of the battery module 4. Of course, they may also be arranged in any other manner. Furthermore, the multiple battery cells 5 may be secured using fasteners. In some embodiments, the battery module 4 may further include a housing having a storage space, wherein the multiple battery cells 5 are housed in the storage space.

[0302] In some embodiments, the battery modules 4 may be assembled into a battery pack 1. The battery pack may contain one or more battery modules. Those skilled in the art may select an appropriate number based on the application and capacity of the battery pack.

[0303] In some embodiments, the battery module 4 may include a battery box that provides a receiving space in which the plurality of battery cells 5 are received.

[0304] Figures 10 and 11 illustrate an exemplary battery pack 1. Referring to Figures 10 and 11 , the battery pack 1 may include a battery case and multiple battery modules 4 disposed within the battery case. The battery case comprises an upper case 2 and a lower case 3. The upper case 2 can be positioned over the lower case 3 to form an enclosed space for accommodating the battery modules 4. The multiple battery modules 4 can be arranged in any manner within the battery case.

[0305] Battery cells can be used as power sources or energy storage units for electrical devices. These devices may include, but are not limited to, mobile devices (e.g., mobile phones, laptops, etc.), electric vehicles (e.g., pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships, satellites, and energy storage systems.

[0306] As an electrical device, a battery cell or a battery system can be selected according to its usage requirements.

[0307] Figure 12 shows an example of an electric device 6. The electric device 6 is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle. To meet the electric device's requirements for high power and high energy density of battery cells or battery systems, a battery pack or battery module may be used.

[0308] As another example, an electric device may be a mobile phone, a tablet computer, a laptop computer, etc. Such an electric device is generally required to be lightweight and thin, and may use a battery cell or a battery system as a power source.

[0309] Below, some more detailed embodiments of the application are described. The embodiment described below is exemplary, is only used to explain the application, and can not be construed as limiting the application. In the embodiment, if no technology or condition is indicated, it is carried out according to the description above, or according to the technology or condition described in the document in this area or according to the product specification. Reagents therefor or instrument are not indicated by the manufacturer, and are conventional products that can be obtained by commercial purchase, or can be synthesized in a conventional manner by commercially available products.

[0310] In the following examples, room temperature refers to 20°C to 30°C.

[0311] It is understood that the ingot with the predetermined shape and size can also be prepared into other shapes and sizes to meet the needs of different situations, and is not limited to the shape and size of the sample required for the test. The following examples use the same refining agent.

[0312] 1. Preparation of aluminum alloy materials

[0313] (1) A pure aluminum ingot is heated to 740°C to 760°C, kept warm and melted, and then a material containing the Mn element is added in the form of an aluminum-manganese master alloy; after the material containing the Mn element is melted, the temperature is lowered to 710°C to 730°C, and alloying element materials containing the Si element, the Mo element, the Zr element, the Sc element, and the B element are added and melted; after the alloying element materials are melted, the slag is skimmed, a refining agent is added, and after skimming, a material containing the Sr element is added, and an ingot with a preset shape and preset size is obtained by casting. The preset shape and preset size are the sample sizes required for the test.

[0314] (2) The ingot is kept at 450°C to 620°C (optionally 540°C to 620°C) for 1 to 2 hours, and then water-cooled to room temperature (e.g., 20°C to 30°C) to obtain an aluminum alloy material. The obtained aluminum alloy material can be used as the main material or component material of a battery case, including but not limited to the main material or component material of a lithium battery case, a fuel cell case, etc.

[0315] (II) Examples and Comparative Examples

[0316] Example 1.

[0317] (1) Select alloy composition

[0318] The aluminum alloy's nominal composition, by mass percentage, is as follows: Si: 8.5%, Mn: 0.45%, Mo: 0.05%, Zr: 0.01%, Sr: 0.02%, Sc: 0.1%, B: 0.05%, with the remainder being Al. See Table 1.

[0319] The ingredients are shown in Table 1.

[0320] Taking the Mn element as an example, the corresponding ingredients of the Mn element (as shown in Table 1) can be recorded as "Mn ingredients".

[0321] Table 1. Melting ratio of aluminum alloy materials in Example 1

[0322] In Table 1, Bal. represents the matrix element, and is the balance in Table 1.

[0323] (2) Alloy smelting

[0324] First, a pure aluminum ingot is placed in a melting furnace and heated to 750°C. After the ingot is melted, Mn is added as an aluminum-manganese master alloy. After the Mn ingredient is melted and the temperature drops to 720°C, the corresponding ingredients of Si, Mo, Zr, Sc, and B are added and melted. After the above elements are melted, the ingot is allowed to stand and slag is removed. A refining agent is added, and after the slag is removed, the corresponding ingredients of Sr are added. Finally, the ingot is cast.

[0325] (3) Heat treatment

[0326] The ingot was kept at 580° C. for 40 h and then water-cooled to room temperature to obtain an aluminum alloy material.

[0327] Example 2. Aluminum alloy ingots and aluminum alloy materials are prepared using a method that is basically the same as that of Example 1, except that the alloy composition is different.

[0328] In terms of mass percentage, the constituent elements of the aluminum alloy material are (nominal composition): Si: 9.5%, Mn: 0.65%, Mo: 0.10%, Zr: 0.07%, Sr: 0.04%, Sc: 0.2%, B: 0.15%, and the rest is Al.

[0329] Example 3. Aluminum alloy ingots and aluminum alloy materials are prepared using a method that is basically the same as that in Example 1, except that the alloy composition is different.

[0330] The constituent elements of the aluminum alloy material, calculated by mass percentage (nominal composition), are: Si: 11.5%, Mn: 0.95%, Mo: 0.20%, Zr: 0.15%, Sr: 0.06%, Sc: 0.3%, B: 0.25%, and the remainder is Al.

[0331] Example 4. Aluminum alloy ingots and aluminum alloy materials are prepared using a method that is basically the same as that in Example 1, except that step (2) is different.

[0332] Step (2) in Example 4 is as follows: first, a pure aluminum ingot is placed in a melting furnace and heated to 740°C. After the ingot is melted at this temperature, Mn is added in the form of an aluminum-manganese master alloy. After the Mn ingredient is melted and the temperature drops to 710°C, Si ingredient, Mo ingredient, Zr ingredient, Sc ingredient, and B ingredient are added and melted. After the above elements are melted, the ingot is allowed to stand and slag is removed. A refining agent is added, and after the slag is removed, Sr ingredient is added. Finally, the ingot is cast by casting.

[0333] Example 5. Aluminum alloy ingots and aluminum alloy materials are prepared using a method basically the same as that of Example 1, except that step (2) is different.

[0334] Step (2) in Example 5 is as follows: first, a pure aluminum ingot is placed in a melting furnace and heated to 760°C. After the ingot is melted at this temperature, Mn is added in the form of an aluminum-manganese master alloy. After the Mn ingredient is melted and the temperature drops to 730°C, Si ingredient, Mo ingredient, Zr ingredient, Sc ingredient, and B ingredient are added and melted. After the above elements are melted, the ingot is allowed to stand and slag is removed. A refining agent is added, and after the slag is removed, Sr ingredient is added. Finally, the ingot is cast by casting.

[0335] Example 6. Aluminum alloy ingots and aluminum alloy materials are prepared using a method basically the same as that of Example 1, except that step (3) is different.

[0336] Step (3) in Example 6 is as follows: the ingot is allowed to stand at 540° C. for 1 hour, and then water-cooled to room temperature to obtain an aluminum alloy material.

[0337] Example 7. Aluminum alloy ingots and aluminum alloy materials are prepared using a method basically the same as that of Example 1, except that step (3) is different.

[0338] Step (3) in Example 7 is as follows: the ingot is allowed to stand and kept at 620° C. for 1.75 h, and then water-cooled to room temperature to obtain an aluminum alloy material.

[0339] Example 8. Aluminum alloy ingots and aluminum alloy materials are prepared using a method basically the same as that of Example 1, except that step (3) is different.

[0340] Step (3) in Example 8 is as follows: the ingot is allowed to stand at 450° C. for 2 h, and then water-cooled to room temperature to obtain an aluminum alloy material.

[0341] Example 9. Aluminum alloy ingots and aluminum alloy materials are prepared using a method basically the same as that of Example 1, except that step (3) is different.

[0342] Step (3) in Example 9 is as follows: the ingot is allowed to stand at 550° C. for 1.25 h, and then water-cooled to room temperature to obtain an aluminum alloy material.

[0343] Comparative Example 1.

[0344] (1) Select alloy composition

[0345] In terms of mass percentage, the constituent elements of the aluminum alloy material are (nominal composition): Si: 7.5%, Cu: 2.5%, Mg: 0.1%, Zn: 0.2%, Mn: 0.02%, Fe: 0.7%, and the rest is Al.

[0346] (2) Alloy smelting

[0347] First, pure aluminum ingots are placed in a melting furnace and heated to 740°C. After the ingots are melted, Mn is added. After the Mn is melted, Cu is added. After the temperature drops to 710°C, the remaining alloying elements, such as Si, Ti, Zn, and Sr, are melted. After the above elements are melted, Mg is added. After the Mg element melts, the ingot is allowed to stand and slag is removed. A refining agent is added. After the slag is removed, Ti and Sr are added. Finally, the ingot is cast.

[0348] (3) Heat treatment

[0349] The ingot is kept at 550°C for 2 hours and then water-cooled to room temperature to obtain an aluminum alloy material, which can be used as a material for a battery case, such as a lithium battery case, a fuel cell case, etc.

[0350] Comparative Example 2. Aluminum alloy ingots and aluminum alloy materials were prepared using a method that is basically the same as that in Comparative Example 1, except that step (2) is different.

[0351] Step (2) in Comparative Example 2 is as follows: first, a pure aluminum ingot is placed in a smelting furnace and heated to 800°C. After the ingot is melted at this temperature, Mn is added. After the Mn is melted, Cu is added. After the temperature drops to 750°C, Si, Ti, Zn, Sr and other alloying elements are added and melted. After the above elements are melted, Mg is added. After the Mg element is melted, the ingot is allowed to stand and slag is skimmed. A refining agent is added. After the slag is skimmed, Ti and Sr are added. Finally, an ingot is cast by casting.

[0352] Comparative Example 3. Aluminum alloy ingots and aluminum alloy materials were prepared using a method substantially the same as that of Example 1, except that the alloy composition was substantially consistent with that of A380 aluminum alloy.

[0353] Comparative Example 4. Aluminum alloy ingots and aluminum alloy materials were prepared using a method substantially the same as that of Example 1, except that the alloy composition was substantially consistent with that of the AlSi9MnMoZr aluminum alloy.

[0354] The nominal composition of the aluminum alloy materials in each embodiment and comparative example can be found in Table 2.

[0355] Table 2.

[0356] In Table 2, “ / ” indicates that the element component is not actively added.

[0357] The chemical composition of the A380 aluminum alloy in Comparative Example 3 can be found in Table 3.

[0358] Table 3. Elemental composition of A380 aluminum alloy.

[0359] In Table 3, “ / ” indicates that the element component is not actively added.

[0360] 2. Test and Analysis Methods

[0361] (1) Actual component analysis

[0362] Inductively coupled plasma optical emission spectrometer (ICP instrument, Avio 5000) was used for elemental analysis to accurately measure the actual composition of the aluminum alloy material.

[0363] (2) Microstructure analysis

[0364] 1. Phase analysis

[0365] X-ray diffraction (XRD) was used to detect the phase with higher content.

[0366] XRD test instrument and parameters: D8 Advance Da Vinci X, Cu Kα1, scanning range (2θ) 20° to 110°, scanning speed 5° / min.

[0367] It should be noted that during XRD phase detection, only phases with a content greater than 5 wt% will have obvious diffraction peaks. Low-content alloy phases with a content of no more than 5% are analyzed by energy dispersive spectrometer (EDS).

[0368] FESEM+EDS test instrument and parameters: FEI NOVA NanoSEM 230 field emission scanning electron microscope (FESEM+EDS), ETD probe type (det), 15 kV accelerating voltage (HV). Other parameters can be seen in Figure 3, where the magnification (mag) is 1000x, the working distance (WD) is 6.5 mm, the image width (HFW) is 298 μm, and the beam spot diameter (spot) is 5.5 nm.

[0369] 2. Metallographic structure analysis

[0370] Instrument and test parameters: CX40M metallographic microscope, magnifications include 25x, 100x, 20x, 200x, 500x and 1000x, and other magnifications can also be selected.

[0371] 3. Analysis method of mass fraction of different alloy phases:

[0372] Jmatpro simulation calculation.

[0373] (3) Mechanical properties testing and corrosion detection

[0374] The aluminum alloy materials prepared in Examples 1 to 9 and Comparative Examples 1 to 4 were subjected to hardness testing, tensile testing, and corrosion testing in accordance with GB / T 4340.1-1999 Metal Vickers hardness test Part 1: Test method.

[0375] 1. Hardness test

[0376] Instrument: Hardness tester.

[0377] Test parameters: Loading load 0.1kg.

[0378] 2. Tensile test:

[0379] (1) Sample size, as shown in Figure 8, in millimeters (mm), where R2.5 indicates a radius of 2.5 mm.

[0380] (2) Testing instrument: Z20 universal electronic testing machine.

[0381] (3) Test and analysis methods:

[0382] Aluminum alloy tensile specimens were wrapped with blue film, leaving only the test surface. The test lasted 600 hours, with samples collected every 24 hours for tensile testing. At least three replicates were used for each test.

[0383] Mechanical properties tests were performed on tensile specimens at different corrosion stages to obtain stress-strain curves. These were then analyzed to determine tensile strength (UTS, also known as tensile strength or ultimate tensile strength), elongation (El), and yield strength (YS). A higher elongation indicates better ductility.

[0384] (4) The tensile fracture morphology can be tested and analyzed using FEI NOVA NanoSEM 230.

[0385] 3. Corrosion test

[0386] (1) Electrochemical corrosion test

[0387] Electrochemical corrosion includes: open circuit voltage test, AC impedance test, and potentiodynamic polarization test.

[0388] Test solution: 3.5 wt% NaCl aqueous solution.

[0389] Before the test, the die-cast aluminum alloy was cut into samples of 10 mm × 10 mm × 2 mm and the samples were cold mounted with epoxy resin to ensure that only 1 cm of the exposed area was 2 The test surface is also ground with sandpaper, then polished with a polishing agent until the sample surface is neat and bright, cleaned with ethanol, and dried for later use.

[0390] During the test, the open circuit voltage (OCP) of the sample was first measured. After the OCP stabilized for 60 minutes, the sample was subjected to an alternating current impedance spectroscopy (EIS) to measure the electrochemical impedance spectroscopy at different AC frequencies. A 10mV AC sine wave was used as the excitation voltage, and the test frequency was controlled within 0.01Hz to 105Hz.

[0391] After the test, the EIS results were fitted with an equivalent circuit to analyze the parameters of each component in the equivalent circuit diagram. Following the AC impedance test, the sample was subjected to potentiodynamic polarization testing. The scan rate was 0.167 mV / s, starting from an OCP potential of -300 mV, until the current exceeded 1 mA. After the test, the polarization characteristics of the sample were then Tafel fitted using ZSimpWin v3.40 software.

[0392] (2) Salt spray corrosion test

[0393] The test was conducted at 35°C using a 3.5 wt% NaCl aqueous solution.

[0394] The macromorphology, micromorphology, corrosion mass loss and corrosion rate of the box material were analyzed every 24 hours for a total test time of 600 hours.

[0395] Before the test, a 15mm×15mm×2mm block of aluminum alloy sample was wrapped with a blue film on the non-test surface. The test surface was ground, polished, and dried before being weighed W0. The total test duration was 600 hours. During the test, a batch of samples was taken every 24 hours for observation of the surface macromorphology and micromorphology. After observation, chromic acid cleaner (20g / L Cr2O3+50mL / L H3PO4) was used to remove corrosion products on the sample surface and the sample was weighed again to calculate the corrosion rate and conduct morphological observation. The test duration of the i-th sampling was recorded as Ti, and the weight at the i-th sampling was recorded as Wi. At least three parallel samples were set for each test.

[0396] (A) Macromorphology testing method

[0397] Samples: The corrosion time points for sampling were as described above.

[0398] Instrument: CX40M metallographic microscope. The above-mentioned test methods can be used.

[0399] (B) Micromorphology testing method

[0400] Samples: The corrosion time points for sampling were as described above.

[0401] Instrument: FEI NOVA NanoSEM 230. The aforementioned test method can be used.

[0402] (C) Corrosion mass loss and corrosion rate analysis methods

[0403] The quality loss of the i-th sampling is W=W0-Wi.

[0404] The corrosion rate Ri at the time of sampling for the i-th time can be substituted into formula (I) to calculate: Corrosion rate = (K×W) / (A×Ti×D)mm / y (I)

[0405] In formula (I): K = 8.64 × 10 4 , K is the time constant;

[0406] W is the mass difference before and after the test = W0-Wi, in mg;

[0407] A is the test surface area 2.25cm 2 , the unit is cm 2 ;

[0408] Ti is the test time of the i-th sampling, in h;

[0409] D=2.7g / cm 3 , D is the material density.

[0410] "mm / y" means millimeters per year.

[0411] (3) Immersion corrosion test

[0412] A 3.5 wt% NaCl aqueous solution was used.

[0413] Staged immersion corrosion involves analyzing the macromorphology, micromorphology, and corrosion rate of the box material every 10 days for a total test time of 30 days. In the application, 1 day = 1 day.

[0414] The sample for the immersion corrosion test may be a block of 15 mm x 15 mm x 2 mm.

[0415] Before the test, the test surface was ground and polished, then rinsed with deionized water and ethanol in turn. After drying and weighing, the sample was placed in a desiccator for storage and standby use. During the test, the sample was placed in a container and 500 mL of corrosion solution was added. The composition of the corrosion solution is: 3.5 wt% NaCl aqueous solution. After sealing, the entire container was placed in a constant temperature water bath tank with the temperature set to 25°C. Samples were taken every 10 days (i.e., the test time was 10 days, 20 days, and 30 days respectively) to observe the macroscopic and microscopic morphologies of the sample surface after corrosion. Subsequently, the corrosion products on the sample surface were removed, the sample mass before and after corrosion was compared, and the corresponding immersion corrosion rate was calculated. Three parallel samples were set for each test.

[0416] 3. Test Results Analysis

[0417] The experimental group of Example 1 is also recorded as "N2", and the prepared aluminum alloy material is also recorded as N2 alloy.

[0418] 1. Comparison between nominal composition and actual composition

[0419] Taking Example 1 as an example, the ICP test results show that the actual composition of the aluminum alloy material is close to its nominal composition, indicating good melting results. See Table 4. No Cu, Mg, or Zn elements were found in any of the examples.

[0420] Table 4. Nominal composition and actual composition of aluminum alloy materials in Example 1

[0421] In Table 4, “ / ” indicates that the element component is not actively added.

[0422] The element contents in Table 4 refer to the mass percentage in the aluminum alloy material, in wt%.

[0423] (2) Phase analysis

[0424] The differences between Examples 1-7 are primarily in the grain size and distribution of the alloy phases, which are not significant. Example 1 will be used for this description. The metallographic structure of the aluminum alloy material prepared in Example 1 can be found in Figure 1 , the microstructure and element distribution diagram can be found in Figure 2 , and the FESEM+EDS point scan image (SEM-EDS image) and the analysis results of four exemplary point scan positions can be found in Figure 3 . The "-" in Figure 3 indicates that the results are below the detection limit. Figure 3 allows analysis of the chemical composition and distribution of the alloy phases.

[0425] According to the above analysis method, the aluminum alloy material of Example 1 mainly includes primary α-Al matrix and fine fibrous Al-Si eutectic structure, including AlB x Strengthening phase and AlSiMnSc strengthening phase, in addition there are MnAl6, needle-shaped AlSiMnFe / Sc and other alloy phases. Among them, AlB x Strengthening phase includes AlB 12 The introduction of Sc reduces the needle-like AlSiMnFe phase, thereby reducing the adverse effects of impurity phases.

[0426] Through simulation calculation, the mass fractions of several different alloy phases in each embodiment are respectively in accordance with:

[0427] AlB x The mass fraction of the strengthening phase in the aluminum alloy material meets the following range: 0.05% to 0.1%;

[0428] The mass fraction of the AlSiMnSc strengthening phase in the aluminum alloy material meets the following range: 0.07% to 0.2%;

[0429] The mass fraction of the MnAl6 alloy phase in the aluminum alloy material satisfies the following range: 0.55% to 1.25%, and further satisfies the following range: 0.45% to 1.3%.

[0430] The mass fraction of the AlSiMnFe phase in the aluminum alloy material satisfies ≤0.2%, and further satisfies ≤0.1%;

[0431] The mass fraction of the AlSiMnFe / Sc alloy phase in the aluminum alloy material satisfies ≤0.2%, and further satisfies 0.07% to 0.2%.

[0432] (3) Mechanical properties testing and corrosion detection

[0433] According to the test results of mechanical properties test and corrosion detection, each of Examples 1-9 has good mechanical properties and excellent corrosion resistance, which is significantly better than Comparative Examples 1-4.

[0434] Figure 4 shows the curves of mass fraction, elastic modulus, thermal conductivity and density of AlSi9MnMoZr alloy material and aluminum alloy material (N2 alloy) in Example 1 as a function of temperature, obtained by Jmatpro analysis; wherein, mass fraction refers to the mass fraction of the aluminum alloy material at different temperatures relative to the initial mass of the aluminum alloy material in the unheated state, reflecting the thermal weight loss of the aluminum alloy material. These indicators of N2 alloy

[0435] FIG5 is a potentiodynamic polarization curve of the aluminum alloy material in Example 1, where the horizontal axis is the chemical potential (unit is V) and the vertical axis is the current density (A / cm 2 ). Figure 6 shows the AC impedance test results of the aluminum alloy material (N2 alloy) in Example 1. Whether it is low frequency or high frequency, N2 alloy shows higher impedance and phase angle. The capacitance ring diameter of N2 alloy is larger, R sl Or R ct All of them are higher than AlSi9MnMoZr alloy, indicating that N2 alloy has better capacitance performance and higher charge transfer resistance. In addition, the corrosion current density (I corr ) is only 27.8% of that of AlSi9MnMoZr alloy, and its polarization resistance (Rp) is also higher. sl 、R ct The surface resistance and charge transfer resistance of each alloy used as the working electrode are shown respectively.

[0436] FIG7 is a surface macroscopic morphology of the aluminum alloy material in Example 1 at different corrosion times in the salt spray corrosion test, 24 days (d), with sampling every day.

[0437] The results of the mechanical property tests and corrosion rate analysis of each embodiment and each comparative example are also summarized in Table 5. The corrosion rates in Table 5 are calculated based on the salt spray test results. The test results of other corrosion tests are basically consistent with those of the salt spray test.

[0438] Table 5.

[0439] The hardness, tensile strength and elongation in Table 5 are all initial values ​​of the aluminum alloy material after being made, without corrosion. Taking Comparative Example 3 as an example, the test and analysis results of each comparative example are described.

[0440] In Comparative Example 3, the A380 alloy is mainly composed of a columnar or nearly equiaxed α-Al matrix phase and a fine Al-Si eutectic structure. In addition, there are some bone-like or needle-like alloy phases near the eutectic structure. Part of the Cu element in the A380 alloy is dissolved in the α-Al matrix; the other part forms a bone-like or needle-like Cu-rich phase, which is identified as an Al2Cu phase by elemental analysis.

[0441] A salt spray corrosion test was conducted on the A380 die-cast aluminum alloy (Comparative Example 3), and the surface macromorphology of the samples at different corrosion times was analyzed. The A380 alloy was severely corroded, and the sample accumulated a large amount of white corrosion products. Due to the occurrence of general corrosion, the alloy surface was quickly covered with corrosion products when the corrosion time was short (1d to 6d). Subsequently, the accumulation area and thickness of the surface corrosion products continued to increase with the extension of the corrosion time. The sample surface showed a transition from the initial dark color of corrosion to being covered with a large amount of white corrosion products.

[0442] Microstructures of the A380 die-cast aluminum alloy (Comparative Example 3) during the early and late stages of the salt spray corrosion test showed that the A380 alloy exhibited uniform corrosion morphology. Furthermore, the corrosion was severe, with a high number of corrosion products. The corrosion products on the surface of the A380 alloy were numerous and thick.

[0443] The microstructure of the die-cast aluminum alloy A380 (Comparative Example 3) after removing the corrosion products shows that a large number of corrosion pits are distributed around the Al-Si eutectic structure of the A380 alloy. Because the Al2Cu phase is distributed near the Al-Si eutectic structure, the intergranular corrosion tendency of the Al-Si eutectic structure is further aggravated. In addition, the solid solution of a small amount of Cu in the matrix will increase the potential difference between the intergranular and intragranular, and the potential of the Al2Cu phase is relatively positive. At the same time, the potential of the matrix phase with a higher Cu content is also relatively positive. At this time, the matrix with a lower Cu content will act as a cathode phase, forming an electrochemical micro-battery with the nearby Cu-rich matrix phase and Al2Cu phase locally, causing the Cu-poor solid solution matrix phase to continuously corrode, resulting in the disappearance of grain boundaries.

[0444] The analysis results of the mass loss and corresponding corrosion rate of A380 die-cast aluminum alloy (Comparative Example 3) under different salt spray corrosion times show that the corrosion weight loss and corrosion rate of A380 alloy are both higher.

[0445] According to the test and analysis results of the tensile test, the changing trends of the mechanical properties and corrosion time were analyzed. It was found that the yield strength and tensile strength of the A380 alloy (Comparative Example 3) showed a rapid downward trend with the increase of corrosion time, which was particularly obvious in the early stage of corrosion (1d to 4d). The yield strength and tensile strength dropped to 77.5% and 76% of the values ​​before corrosion, respectively. Subsequently, the rate of performance degradation slowed down, and the yield strength and tensile strength finally dropped to 65.4% and 52.5% of the values ​​before corrosion, respectively.

[0446] The above description of various embodiments and examples tends to emphasize the differences between the various embodiments and examples. The same or similar aspects can be referenced to each other and will not be repeated here for the sake of brevity.

[0447] The various technical features of the above-described implementation methods or examples can be combined arbitrarily. In order to make the description concise, not all possible combinations of the various technical features in the above-described implementation methods or examples are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0448] It should be noted that the present application is not limited to the above-mentioned embodiments and examples. The above-mentioned embodiments and examples are only examples, and within the scope of the technical solution of the present application, embodiments that have substantially the same structure as the technical idea and exert the same effect are all included in the technical scope of the present application. The above embodiments and examples only express several embodiments of the present application, and their descriptions are relatively detailed, but they cannot be understood as limiting the scope of the patent. In addition, without departing from the scope of the subject matter of the present application, other methods of applying various modifications that can be thought of by those skilled in the art to the above embodiments or examples, and combining some of the constituent elements in the embodiments or examples to construct the above embodiments are also included in the scope of the present application.

Claims

1. An aluminum alloy material comprising the following constituent elements: Si, Mn, Mo, Zr, Sr, Sc, B, matrix element Al and unavoidable impurity elements; in, The aluminum alloy material includes Al-Si eutectic phase, AlB x Strengthening phase and AlSiMnSc strengthening phase, the AlB x The strengthening phase includes at least an AlB2 strengthening phase; The mass percentage of Mo in the aluminum alloy material is ≤0.25%; The mass percentage of Zr in the aluminum alloy material is ≤0.2%.

2. An aluminum alloy material, wherein: Measured by mass percentage, the aluminum alloy material includes 8% to 11.5% of Si element, 0.05% to 0.35% of Sc element, 0.01% to 0.4% of B element, 0.3% to 1.0% of Mn element, 0.02% to 0.25% of Mo element, 0.01% to 0.2% of Zr element, 0.02% to 0.08% of Sr element, matrix element Al and inevitable impurity elements.

3. The aluminum alloy material according to claim 2, wherein: The aluminum alloy material includes Al-Si eutectic phase, AlB x Strengthening phase and AlSiMnSc strengthening phase.

4. The aluminum alloy material according to claim 1 or 3, which satisfies one or more of the following characteristics: The AlB x The mass fraction of the strengthening phase in the aluminum alloy material is ≤0.1%, and can be optionally 0.05% to 0.1%; The mass fraction of the AlSiMnSc strengthening phase in the aluminum alloy material is ≤0.2%, and can be optionally 0.07% to 0.2%.

5. The aluminum alloy material according to any one of claims 1 to 4, wherein The aluminum alloy material meets one or more of the following characteristics: The mass percentage of Si element in the aluminum alloy material is 8% to 11.5%, optionally 8.5% to 11.5%, and further optionally 8.5% to 11%; The mass percentage of Sc element in the aluminum alloy material is 0.05% to 0.35%, optionally 0.1% to 0.35%, and further optionally 0.1% to 0.3%; The mass percentage of B element in the aluminum alloy material is 0.01% to 0.4%, optionally 0.01% to 0.25%, and further optionally 0.01% to 0.1%; The mass percentage of Mn element in the aluminum alloy material is 0.3% to 1.0%, optionally 0.45% to 0.95%, and further optionally 0.45% to 0.70%.

6. The aluminum alloy material according to any one of claims 1 to 5, wherein The aluminum alloy material includes a MnAl6 alloy phase; optionally, the mass fraction of the MnAl6 alloy phase in the aluminum alloy material is 0.55% to 1.25%, and further optionally 0.45% to 1.3%.

7. The aluminum alloy material according to any one of claims 1 to 6, wherein The aluminum alloy material meets one or more of the following characteristics: The mass percentage of Mo element in the aluminum alloy material is 0.02% to 0.25%, optionally 0.04% to 0.2%, and further optionally 0.05% to 0.1%; The mass percentage of Zr element in the aluminum alloy material is 0.01% to 0.2%, optionally 0.01% to 0.15%, and further optionally 0.05% to 0.15%.

8. The aluminum alloy material according to any one of claims 1 to 7, wherein The mass percentage of Sr element in the aluminum alloy material is 0.02% to 0.08%, optionally 0.02% to 0.06%, and further optionally 0.02% to 0.05%.

9. The aluminum alloy material according to any one of claims 1 to 8, wherein Measured by mass percentage, the aluminum alloy material includes 8.5% to 11.5% of Si element, 0.1% to 0.35% of Sc element, 0.01% to 0.25% of B element, 0.45% to 0.95% of Mn element, 0.05% to 0.2% of Mo element, 0.01% to 0.15% of Zr element, 0.02% to 0.06% of Sr element, matrix element Al and the unavoidable impurity elements.

10. The aluminum alloy material according to any one of claims 1 to 8, wherein Measured by mass percentage, the aluminum alloy material includes 8.5% to 11% of Si element, 0.1% to 0.3% of Sc element, 0.01% to 0.1% of B element, 0.45% to 0.70% of Mn element, 0.05% to 0.1% of Mo element, 0.05% to 0.15% of Zr element, 0.02% to 0.05% of Sr element, matrix element Al and the unavoidable impurity elements.

11. The aluminum alloy material according to any one of claims 1 to 8, wherein Measured by mass percentage, the aluminum alloy material includes 8% to 11.5% of Si element, 0.05% to 0.35% of Sc element, 0.01% to 0.4% of B element, 0.3% to 1.0% of Mn element, 0.05% to 0.25% of Mo element, 0.01% to 0.2% of Zr element, 0.02% to 0.08% of Sr element, the unavoidable impurity elements and the balance of Al element.

12. The aluminum alloy material according to any one of claims 1 to 8, wherein Measured by mass percentage, the aluminum alloy material includes 8% to 11.5% of Si element, 0.05% to 0.35% of Sc element, 0.05% to 0.4% of B element, 0.3% to 1.0% of Mn element, 0.05% to 0.25% of Mo element, 0.01% to 0.2% of Zr element, 0.02% to 0.08% of Sr element, the unavoidable impurity elements and the balance of Al element.

13. The aluminum alloy material according to any one of claims 1 to 12, wherein: The unavoidable impurity elements include Fe element.

14. The aluminum alloy material according to any one of claims 1 to 13, which satisfies one or more of the following characteristics: The mass percentage of Fe element in the aluminum alloy material is ≤0.7%, and optionally, the mass percentage of the unavoidable impurity element in the aluminum alloy material is <0.7%; The aluminum alloy material comprises an AlSiMnFe phase, and optionally, the mass fraction of the AlSiMnFe phase in the aluminum alloy material is ≤0.2%, and further optionally ≤0.1%; The aluminum alloy material includes an AlSiMnFe / Sc alloy phase; optionally, the mass fraction of the AlSiMnFe / Sc alloy phase in the aluminum alloy material is ≤0.2%, and may be 0.07% to 0.2%.

15. The aluminum alloy material according to any one of claims 1 to 14, wherein The aluminum alloy material meets one or more of the following characteristics: The mass percentage of Mg element in the aluminum alloy material is ≤0.1%, optionally ≤0.01%, and further optionally 0%; The mass percentage of Zn element in the aluminum alloy material is ≤0.1%, optionally ≤0.01%, and further optionally 0%; The mass percentage of Cu element in the aluminum alloy material is ≤0.01%, and may be 0%.

16. An aluminum alloy structural part, wherein: The aluminum alloy structural part is a formed body of the aluminum alloy material according to any one of claims 1 to 15.

17. A method for preparing an aluminum alloy structural part, comprising the following steps: The aluminum ingot is heated and melted, and the ingredients determined by the nominal composition of the aluminum alloy material according to any one of claims 1 to 15 are added in the form of a master alloy, and then smelting and slagging are performed to prepare an aluminum alloy refined melt; Casting the aluminum alloy molten metal to obtain an aluminum alloy ingot; The aluminum alloy ingot is heat treated and cooled to obtain the aluminum alloy structural part.

18. A battery box, wherein: The battery box meets at least one of the following characteristics: At least a portion of the structural parts of the battery case comprises the aluminum alloy material according to any one of claims 1 to 15; The battery case comprises the aluminum alloy structural member according to claim 16; and The battery case includes an aluminum alloy structural part prepared by the method for preparing an aluminum alloy structural part according to claim 17.

19. A battery system, wherein: The battery system comprises the battery case as claimed in claim 18 and a battery cell located inside the battery case.

20. The battery system according to claim 19, wherein: The battery cell includes a liquid electrolyte.

21. An electrical device, comprising at least one of the aluminum alloy material according to any one of claims 1 to 15, the aluminum alloy structural part according to claim 16, the aluminum alloy structural part prepared by the method for preparing the aluminum alloy structural part according to claim 17, the battery case according to claim 18, and the battery system according to claim 19 or 20.

22. Use of the aluminum alloy material according to any one of claims 1 to 15 in the preparation of at least one of an aluminum alloy structural part, a battery case, a battery system and an electrical device.

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