Methods of producing mine blast resistant armor from a 7xxx series aluminum alloy

Abstract

Described herein are 7xxx series aluminum alloys and methods of producing armor components, such as for civil or military vehicles made of high strength 7xxx series aluminum alloys requiring resistance to underbelly threats (e.g., mine blasts applications). The method of producing armor components for civil or military vehicles includes a two-step over-aging process to increase the corrosion resistance of the aluminum alloy while maintaining physical and mechanical properties.

Description

PRIORITY CLAIM

[0001] This application claims the benefit of and priority to U.S. Provisional Application No. 63 / 480,939, filed on Jan. 20, 2023, the entire contents and disclosures of which are incorporated by reference herein.FIELD

[0002] The present disclosure relates to metallurgy generally and more specifically to processing techniques for producing armor components used for manufacturing armor hulls and add-on appliques, such as panels mounted on the outside of military vehicles or the like.BACKGROUND

[0003] Generally, an armor component includes a metal panel, typically of steel, aluminum, titanium, or alloys thereof. Such panels have an excellent ability to absorb kinetic energy of a penetrator during impact. However, particularly if they are made of alloys such as steel, the panels are heavy and have low effectiveness in terms of absorption of energy related to the weight carried by the vehicle. In some examples, high-strength aluminum alloys may be used given their light weight.SUMMARY

[0004] The term embodiment and like terms are intended to refer broadly to all of the subject matter of this disclosure and the claims below. Statements containing these terms should be understood not to limit the subject matter described herein or to limit the meaning or scope of the claims below. Embodiments of the present disclosure covered herein are defined by the claims below, not this summary. This summary is a high-level overview of various aspects of the disclosure and introduces some of the concepts that are further described in the Detailed Description section below. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used in isolation to determine the scope of the claimed subject matter. The subject matter should be understood by reference to appropriate portions of the entire specification of this disclosure, any or all drawings and each claim.

[0005] In a first aspect, provided herein are armor components, such as armor components comprising a metal product, the metal product. In some examples, the metal product comprises a 7xxx series aluminum alloy. Optionally, the metal product is a plate having a thickness of from 12.7 mm to 76.2 mm. In some examples, the metal product exhibits a yield strength of from about 400 MPa to 495 MPa. In some examples, the metal product exhibits an ultimate tensile strength of from about 450 MPa to 545 MPa. In some examples, the metal product exhibits an elongation of about 9% to 16%. In some examples, the 7xxx series aluminum alloy comprises about 7.1 wt. % to 7.5 wt. % Zn, about 1.90 wt. % to 2.25 wt. % Mg, about 1.3 wt. % to 1.8 wt. % Cu, about 0.05 wt. % to 0.4 wt. % of a dispersoid forming element, about 0.01 wt. % to 0.06 wt. % Ti, up to about 0.15 wt. % Si, up to 0.15 wt. % Fe, and Al. In some examples, the 7xxx series aluminum alloy comprises impurities of up to 0.15 wt. % and a balance Al. Optionally, the dispersoid forming element comprises one or more of Zr, Sc, V, Hf, Ti, Cr, or Mn. In some examples, the dispersoid forming element comprises Zr in a range of from 0.06 wt. % to 0.15 wt. %. In some examples, the 7xxx series aluminum alloy comprises Zn and Mg with a ratio (e.g., wt. % ratio) of Zn to Mg of less than or about 4.

[0006] The armor components and metal products described herein may be suitable for mine-blast resistance or as under belly vehicle protection panels, for example. The mechanical characteristics or other characteristics of the armor components may be sufficient to meet various military specifications, such as a U.S. MIL-DTL-32375B or MIL-DTL-32375C specification. In some examples, the metal product exhibits an absorbed impact energy of from 40 J / cm2 to 100 J / cm2. In some examples, the yield strength is from about 410 MPa to about 470 MPa. In some examples, the ultimate tensile strength is from about 470 MPa to about 530 MPa. In some examples, the elongation is from about 12% to 16%. In some examples, the yield strength the ultimate tensile strength and / or the elongation are measured along a LT direction. In some examples, the metal product meets minimum mechanical and / or ballistic requirements of a US military specification, such as a MIL-DTL-32375B specification or MIL-DTL-32375C (e.g., a Type B specification). In some examples, the metal product exhibits an exfoliation corrosion susceptibility of EA or EB according to an ASTM G34 standard. For example, the metal product may exhibit a stress-corrosion cracking resistance of at least 30 days according to an ASTM G64 standard, such as at least 40 days.

[0007] In examples, the armor components of this aspect are processed according to suitable processing techniques to achieve the mechanical and other characteristics described. For example, the armor component may be subjected to an over-aging treatment comprising heating to a first temperature of from 110° C. to 130° C. for a first duration of from 4 hours to 12 hours and followed by heating to a second temperature of from 160° C. to 200° C. for a second duration of from 4 hours to 40 hours. Optionally, the second duration is from 6 hours to 25 hours, from 8 hours to 20 hours, or from 10 hours to 18 hours.

[0008] In another aspect, methods of producing armor components are described. In some examples, method of this aspect comprise casting a 7xxx series aluminum alloy into an ingot; homogenizing the ingot; hot rolling the ingot to obtain a metal product; solution heat treating the metal product; quenching the metal product; stretching the metal product to obtain a permanent elongation from 1% to 6% (e.g., from 1% to 2%, from 2% to 3%, from 3% to 4%, from 4% to 5%, or from 5% to 6%); and subjecting the metal product to an over-aging treatment. In examples, the over-aging treatment comprises heating the metal product to a first temperature of from 110° C. to 130° C. for a first duration of from 4 hours to 12 hours and followed by heating the metal product to a second temperature of from 160° C. to 200° C. for a second duration of from 4 hours to 40 hours. In some examples, the second duration is from 10 hours to 18 hours. Methods of this aspect optionally further comprise cold rolling the metal product.

[0009] The methods of this aspect may be suitable for preparing the armor components described above. For example, upon completion of the processing, the metal product may exhibit one or more of a yield strength of from about 400 MPa to 495 MPa, an ultimate tensile strength of from about 450 MPa to 545 MPa, or an elongation of about 9% to 16%.

[0010] Optionally, the 7xxx series aluminum alloy comprises about 7.1 wt. % to 7.5 wt. % Zn, about 1.90 wt. % to 2.25 wt. % Mg, about 1.3 wt. % to 1.8 wt. % Cu, about 0.05 wt. % to 0.4 wt. % of a dispersoid forming element, about 0.01 wt. % to 0.06 wt. % Ti, up to about 0.15 wt. % Si, up to 0.15 wt. % Fe, and Al. In some examples, the 7xxx series aluminum alloy comprises impurities of up to 0.15 wt. % and a balance Al. Optionally, the dispersoid forming element comprises one or more of Zr, Sc, V, Hf, Ti, Cr, or Mn. In some examples, the dispersoid forming element comprises Zr in a range of from 0.06 wt. % to 0.15 wt. %. In some examples, the 7xxx series aluminum alloy comprises Zn and Mg with a ratio (e.g., wt. % ratio) of Zn to Mg of less than or about 4. In some examples, the over-aging treatment generates a microstructure in the metal product providing the yield strength, the ultimate tensile strength, and the elongation specified above. In some examples, the resultant the metal product meets a mechanical or ballistic requirement (e.g., a Type B requirement) of a US military specification MIL-DTL-32375 (e.g., MIL-DTL-32375B or MIL-DTL-32375C).

[0011] Other objects and advantages will be apparent from the following detailed description of non-limiting examples.BRIEF DESCRIPTION OF THE FIGURES

[0012] The specification makes reference to the following appended figures, in which use of like reference numerals in different figures is intended to illustrate like or analogous components.

[0013] FIG. 1 provides a schematic overview of an example method for making a rolled aluminum alloy product.

[0014] FIG. 2 provides a graph of the V50 ballistic testing at various thicknesses of samples subjected to a two-step over-aging process.

[0015] FIG. 3 provides a graph of tensile strength, yield strength, and elongation of samples subjected to a two-step over-aging process to meet minimum mechanical property requirements according to a U.S. MIL-DTL-32375 specification.

[0016] FIG. 4 provides a graph of the absorbed impact energy for aluminum alloy products processed at various thicknesses.DETAILED DESCRIPTION

[0017] Described herein are aluminum alloys and methods for preparing aluminum alloy products made using 7xxx series aluminum alloys to achieve desired physical and mechanical properties such as those described in the U.S. military standard MIL-DTL-32375B (MR) w / Amendment 3 (15 Jan. 2021) or MIL-DTL-32375C (MR) (26 Jun. 2023), hereby incorporated by reference.

[0018] Aluminum alloys that satisfy all the requirements for armor plates are desirable. Some aluminum alloys can meet the requirements and are covered in the U.S. military specification for armor plate MIL-DTL-46027K and 46063H, such as, the AA5083, AA5456, AA5059, and AA7039. It is generally recognized that AA7039 armor plate is better than AA5083 and AA5456 armor plate, although the advantage is more for armor piercing ballistic performance and less for fragmentation simulation performance, at least according to the military specification. However, the alloy AA7039 can present corrosion or stress corrosion problems to a much greater degree than AA5083 and AA5456. As is typical in 7xxx series aluminum alloy, the formation of precipitates (e.g., MgZn2) at the grain boundary may increase the corrosive behavior of the aluminum alloy. Therefore, 7xxx series aluminum alloys may be subjected to over-aging to improve the corrosion resistance of the alloy. Typical over-aging of 7xxx series aluminum alloys include a single or multi-step aging process that results in an aluminum alloy with improved corrosion resistance while resulting in reduced mechanical properties such as reduced strength. The methods of producing 7xxx series aluminum alloys described herein produce an aluminum alloy microstructure that reduces the aluminum alloy's susceptibility to stress corrosion cracking (SCC) while maintaining good mechanical properties (e.g., high yield strength). Specifically, the methods described herein includes a two-step over-aging process of the 7xxx series aluminum alloys, where a first aging step at a temperature of from about 110° C. to about 130° C. for a period of time from 4 hours to 12 hours. Following the first step, a second aging or over-aging step may be performed by heating the product to a second temperature of from 160° C. to 200° C. for a second duration of from 4 hours to 40 hours. These techniques advantageously allow the 7xxx series aluminum alloy product to exhibit strength, elongation, or other characteristics (e.g., ballistic properties) that meet the U.S. military standard MIL-DTL-32375B or MIL-DTL-32375C requirements or otherwise provide mechanical or other characteristics suitable for the applications for which U.S. military standard MIL-DTL-32375B or MIL-DTL-32375C relate. For example, the 7xxx series aluminum alloy product may exhibit a yield strength of from about 400 MPa to 495 MPa, an ultimate tensile strength of from about 450 MPa to 545 MPa, and / or an elongation of about 9% to 16%.Definitions and Descriptions

[0019] As used herein, the terms “invention,”“the invention,”“this invention” and “the present invention” are intended to refer broadly to all of the subject matter of this patent application and the claims below. Statements containing these terms should be understood not to limit the subject matter described herein or to limit the meaning or scope of the patent claims below.

[0020] In this description, reference is made to alloys identified by AA numbers and other related designations, such as “series” or “7xxx.” For an understanding of the number designation system most commonly used in naming and identifying aluminum and its alloys, see “International Alloy Designations and Chemical Composition Limits for Wrought Aluminum and Wrought Aluminum Alloys” or “Registration Record of Aluminum Association Alloy Designations and Chemical Compositions Limits for Aluminum Alloys in the Form of Castings and Ingot,” both published by The Aluminum Association.

[0021] As used herein, a plate generally has a thickness of greater than about 12 mm. For example, a plate may refer to an aluminum product having a thickness of greater than about 12 mm, greater than about 15 mm, greater than about 20 mm, greater than about 25 mm, greater than about 30 mm, greater than about 35 mm, greater than about 40 mm, greater than about 45 mm, or greater than about 50 mm.

[0022] As used herein, a shate (also referred to as a sheet plate) generally has a thickness of from about 4 mm to about 11 mm. For example, a shate may have a thickness of about 4 mm, about 5 mm, about 6 mm, about 7 mm, about 8 mm, about 9 mm, about 10 mm, or about 11 mm.

[0023] As used herein, a sheet generally refers to an aluminum product having a thickness of less than about 4 mm. For example, a sheet may have a thickness of less than about 4 mm, less than about 3 mm, less than about 2 mm, less than about 1 mm, less than about 0.5 mm, or less than about 0.3 mm (e.g., about 0.2 mm).

[0024] Reference may be made in this application to alloy temper or condition. For an understanding of the alloy temper descriptions most commonly used, see “American National Standards (ANSI) H35 on Alloy and Temper Designation Systems.” An F condition or temper refers to an aluminum alloy as fabricated. An O condition or temper refers to an aluminum alloy after annealing. An Hxx condition or temper, also referred to herein as an H temper, refers to a non-heat treatable aluminum alloy after cold rolling with or without thermal treatment (e.g., annealing). Suitable H tempers include HX1, HX2, HX3 HX4, HX5, HX6, HX7, HX8, or HX9 tempers. A T1 condition or temper refers to an aluminum alloy cooled from hot working and naturally aged (e.g., at room temperature). A T2 condition or temper refers to an aluminum alloy cooled from hot working, cold worked, and naturally aged. A T3 condition or temper refers to an aluminum alloy solution heat treated, cold worked, and naturally aged. A T4 condition or temper refers to an aluminum alloy solution heat treated and naturally aged. A T5 condition or temper refers to an aluminum alloy cooled from hot working and artificially aged (at elevated temperatures). A T6 condition or temper refers to an aluminum alloy solution heat treated and artificially aged. A T7 condition or temper refers to an aluminum alloy solution heat treated and artificially overaged. A T8x condition or temper refers to an aluminum alloy solution heat treated, cold worked, and artificially aged. A T9 condition or temper refers to an aluminum alloy solution heat treated, artificially aged, and cold worked. A W condition or temper refers to an aluminum alloy after solution heat treatment.

[0025] As used herein, terms such as “cast metal product,”“cast product,”“cast aluminum alloy product,” and the like are interchangeable and refer to a product produced by direct chill casting (including direct chill co-casting) or semi-continuous casting, continuous casting (including, for example, by use of a twin belt caster, a twin roll caster, a block caster, or any other continuous caster), electromagnetic casting, hot top casting, or any other casting method.

[0026] As used herein, the meaning of “room temperature” can include a temperature of from about 15° C. to about 30° C., for example about 15° C., about 16° C., about 17° C., about 18° C., about 19° C., about 20° C., about 21° C., about 22° C., about 23° C., about 24° C., about 25° C., about 26° C., about 27° C., about 28° C., about 29° C., or about 30° C. As used herein, the meaning of “ambient conditions” can include temperatures of about room temperature, relative humidity of from about 20% to about 100%, and barometric pressure of from about 975 millibar (mbar) to about 1050 mbar. For example, relative humidity can be about 20%, about 21%, about 22%, about 23%, about 24%, about 25%, about 26%, about 27%, about 28%, about 29%, about 30%, about 31%, about 32%, about 33%, about 34%, about 35%, about 36%, about 37%, about 38%, about 39%, about 40%, about 41%, about 42%, about 43%, about 44%, about 45%, about 46%, about 47%, about 48%, about 49%, about 50%, about 51%, about 52%, about 53%, about 54%, about 55%, about 56%, about 57%, about 58%, about 59%, about 60%, about 61%, about 62%, about 63%, about 64%, about 65%, about 66%, about 67%, about 68%, about 69%, about 70%, about 71%, about 72%, about 73%, about 74%, about 75%, about 76%, about 77%, about 78%, about 79%, about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, about 99%, about 100%, or anywhere in between. For example, barometric pressure can be about 975 mbar, about 980 mbar, about 985 mbar, about 990 mbar, about 995 mbar, about 1000 mbar, about 1005 mbar, about 1010 mbar, about 1015 mbar, about 1020 mbar, about 1025 mbar, about 1030 mbar, about 1035 mbar, about 1040 mbar, about 1045 mbar, about 1050 mbar, or anywhere in between.

[0027] All ranges disclosed herein are to be understood to encompass any and all subranges subsumed therein. For example, a stated range of “1 to 10” should be considered to include any and all subranges between (and inclusive of) the minimum value of 1 and the maximum value of 10; that is, all subranges beginning with a minimum value of 1 or more, e.g., 1 to 6.1, and ending with a maximum value of 10 or less, e.g., 5.5 to 10. Unless stated otherwise, the expression “up to” when referring to the compositional amount of an element means that element is optional and includes a zero percent composition of that particular element. Unless stated otherwise, all compositional percentages are in weight percent (wt. %).

[0028] As used herein, the meaning of “a,”“an,” and “the” includes singular and plural references unless the context clearly dictates otherwise.

[0029] In the following examples, aluminum alloy products and their components may be described in terms of their elemental composition in weight percent (wt. %). In each alloy, the remainder is aluminum, with a maximum wt. % of 0.15% for the sum of all impurities.

[0030] Incidental elements, such as grain refiners and deoxidizers, or other additives may be present in the invention and may add other characteristics on their own without departing from or significantly altering the alloy described herein or the characteristics of the alloy described herein.

[0031] Unavoidable impurities, including materials or elements may be present in an alloy in minor amounts due to inherent properties of aluminum or leaching from contact with processing equipment. Some alloys, as described, may contain no more than about 0.25 wt. % of any element besides the alloying elements, incidental elements, and unavoidable impurities.Alloy Compositions and Properties

[0032] Aluminum alloy properties are partially determined by the composition of the aluminum alloy and partially by the microstructure of the resultant product. In certain aspects, the alloy composition may influence whether the alloy can or will have properties adequate for a desired application. In certain aspects, the method by which the aluminum alloy product is processed may influence whether the product can have properties adequate for a desired application. Described herein are aluminum alloy products comprising 7xxx series aluminum alloys. The aluminum alloy products exhibit high strength to weight ratios and improved corrosion resistance. The properties of the aluminum alloy products are achieved, at least in part, due to the compositions, microstructure, and / or methods by which they are prepared.

[0033] In some examples, an aluminum alloy as described herein can comprise up to 0.15 wt. % Si, up to 0.15 wt. % Fe, from 1.30 wt. % to 1.80 wt. % Cu, from 1.90 wt. % to 2.25 wt. % Mg, from 7.10 wt. % to 7.50 wt. % Zn, from 0.01 wt. % to 0.06 wt. % Ti, from 0.05 wt. % to 0.40 wt. % of a dispersoid forming element, and Al. In some examples, the alloy may contain up to 0.15 wt. % of impurities, such as up to 0.05 wt. each of a plurality of different impurities. In some examples, Al may comprise the balance of the alloy composition besides the other elements specified and impurities. Optionally, the alloy may comprise from 0.0 wt. % to 0.05 wt. % Si, from 0.05 wt. % to 0.10 wt. % Si, or from 0.10 wt. % to 0.15 wt. % Si Optionally, the alloy may comprise the alloy may comprise from 0.0 wt. % to 0.05 wt. % Fe, from 0.05 wt. % to 0.10 wt. % Fe, or from 0.10 wt. % to 0.15 wt. % Fe. Optionally, the alloy may comprise from 1.3 wt. % to 1.40 wt. % Cu, from 1.40 wt. % to 1.50 wt. % Cu, from 1.50 wt. % to 1.60 wt. % Cu, from 1.60 wt. % to 1.70 wt. % Cu, or from 1.70 wt. % to 1.8 wt. % Cu. Optionally, the alloy may comprise from 1.90 wt. % to 1.95 wt. % Mg, from 1.95 wt. % to 2.00 wt. % Mg, from 2.00 wt. % to 2.05 wt. % Mg, from 2.05 wt. % to 2.10 wt. % Mg, from 2.10 wt. % to 2.15 wt. % Mg, from 2.15 wt. % to 2.20 wt. % Mg, or from 2.20 wt. % to 2.25 wt. % Mg. Optionally, the alloy may comprise from 7.1 wt. % to 7.15 wt. % Zn, from 7.15 wt. % to 7.20 wt. % Zn, from 7.20 wt. % to 7.25 wt. % Zn, from 7.25 wt. % to 7.30 wt. % Zn, from 7.30 wt. % to 7.35 wt. % Zn, from 7.35 wt. % to 7.40 wt. % Zn, from 7.40 wt. % to 7.45 wt. % Zn, or from 7.45 wt. % to 7.5 wt. % Zn. Optionally, the alloy may comprise from 0.01 wt. % to 0.02 wt. % Ti, from 0.02 wt. % to 0.03 wt. % Ti, from 0.03 wt. % to 0.04 wt. % Ti, from 0.04 wt. % to 0.05 wt. % Ti, or from 0.05 wt. % to 0.06 wt. % Ti. Optionally, the alloy may comprise from 0.05 wt. % to 0.10 wt. % of one or more dispersoid forming elements, from 0.10 wt. % to 0.15 wt. % of one or more dispersoid forming elements, from 0.15 wt. % to 0.20 wt. % of one or more dispersoid forming elements, from 0.20 wt. % to 0.25 wt. % of one or more dispersoid forming elements, from 0.25 wt. % to 0.30 wt. % of one or more dispersoid forming elements, or from 0.35 wt. % to 0.40 wt. % of one or more dispersoid forming elements.

[0034] In some examples, the aluminum alloy includes a dispersoid forming element such as one or more of Zr, Sc, V, Hf, Ti, Cr, or Mn. In some examples, the dispersoid forming element includes Zr in a range of from 0.06 wt. % to 0.15 wt. %, such as from 0.06 wt. % to 0.07 wt. % Zr, from 0.07 wt. % to 0.08 wt. % Zr, from 0.08 wt. % to 0.09 wt. % Zr, from 0.09 wt. % to 0.10 wt. % Zr, from 0.10 wt. % to 0.11 wt. % Zr, from 0.11 wt. % to 0.12 wt. % Zr, from 0.12 wt. % to 0.13 wt. % Zr, from 0.13 wt. % to 0.14 wt. % Zr, or from 0.14 wt. % to 0.15 wt. % Zr. In some examples, the aluminum alloy may have a ratio of Zn to Mg of less than or about 4. For example, the ratio of Zn to Mg may be 4 or less, 3 or less, 2 or less, 1 or less, from 0.1 to 0.5, from 0.5 to 1, from 1 to 1.5, from 1.5 to 2, from 2 to 2.5, from 2.5 to 3, from 3 to 3.5, or from 3.5 to 4.

[0035] The aluminum alloy product produced using the techniques disclosed herein may have physical and mechanical properties that are a result of the composition, microstructure, and / or the method of producing the aluminum alloy. In some examples, subsequent to a two-step over-aging, the aluminum alloy product can exhibit an exfoliation corrosion susceptibility of EA or EB according to an ASTM-G34 standard. In some examples, subsequent to the two-step over-aging, the aluminum alloy product can exhibit a stress-corrosion cracking resistance of at least 30 days according to an ASTM-G64 standard, such as at least 40 days. Beneficially, the methods described herein enable 7xxx series aluminum alloys, such as AA7181 aluminum alloy, to be provided with a balance of corrosion resistance and desirable mechanical properties.

[0036] In some examples, subsequent to the two-step over-aging, the aluminum alloy product can exhibit a yield strength of from about 400 MPa to about 495 MPa, such as from 400 MPa to 410 MPa, from 410 MPa to 420 MPA, from 420 MPa to 430 MPa, from 430 MPa to 440 MPa, from 440 MPa to 450 MPa, from 450 MPa to 460 MPa, from 460 MPa to 470 MPa, from 470 MPa to 480 MPa, from 480 MPa to 490 MPa, or from 490 MPa to 495 MPA. In some examples, after the two-step over-aging, the aluminum alloy product can exhibit an ultimate tensile strength of from about 450 MPa to about 545 MPa, such as from 450 MPa to 460 MPa, from 460 MPa to 470 MPa, from 470 MPa to 480 MPa, from 480 MPa to 490 MPa, from 490 MPa to 500 MPa, from 500 MPa to 510 MPa, from 510 MPa to 520 MPa, from 520 MPa to 530 MPa, from 530 MPa to 540 MPa or from 540 MPa to 545 MPa. In some examples, after the two-step over-aging, the aluminum alloy product can exhibit an elongation of from about 9% to about 16%, such as from 9% to 10%, from 10% to 11%, from 11% to 12%, from 12% to 13%, from 13% to 14%, from 14% to 15%, or from 15% to 16%.

[0037] In some examples, subsequent to the two-step over-aging, the aluminum alloy product may exhibit an absorbed impact energy of from 40 J / cm2 to 100 J / cm2. For example, the alloy product may exhibit an absorbed impact energy of from 40 J / cm2 to 50 J / cm2, 50 J / cm2 to 60 J / cm2, from 60 J / cm2 to 70 J / cm2, from 70 J / cm2 to 80 J / cm2, from 80 J / cm2 to 90 J / cm2, from 90 J / cm2 to 100 J / cm2, from 50 J / cm2 to 90 J / cm2, from 50 J / cm2 to 80 J / cm2.Methods of Producing the Alloys and Aluminum Alloy Products

[0038] The aluminum alloy products described herein can be prepared using suitable methods. For example, aluminum alloys may be cast, homogenized, hot-rolled, cold-rolled, solution heat treated, stretched, artificially over-aged, formed, or the like to generate aluminum alloy products.

[0039] FIG. 1 provides an overview of an example method of making an aluminum alloy product. The method of FIG. 1 begins at 105, where an aluminum alloy 106 is cast to form a cast aluminum alloy product 107, such as an ingot or other cast product. At 110, the cast aluminum alloy product 107 is homogenized to form a homogenized aluminum alloy product 111. At 115, the homogenized aluminum alloy product 111 is subjected to one or more hot rolling passes and optionally one or more cold rolling passes to form a rolled aluminum alloy product 112, which may correspond to an aluminum alloy article, such as an aluminum alloy plate, an aluminum alloy shate, or an aluminum alloy sheet. Optionally, the rolled aluminum alloy product 112 is subjected to additional processing steps, as described below, to form an aluminum alloy article.

[0040] Non-limiting examples of casting processes include a direct chill (DC) casting process or a continuous casting (CC) process. For example, FIG. 1 depicts a schematic illustration of a DC casting process at 105, but other casting processes can be used. A continuous casting system can include a pair of moving opposed casting surfaces (e.g., moving opposed belts, rolls or blocks), a casting cavity between the pair of moving opposed casting surfaces, and a molten metal injector. The molten metal injector can have an end opening from which molten metal can exit the molten metal injector and be injected into the casting cavity.

[0041] A cast aluminum alloy product, such as a cast ingot, cast slab, or other cast product, can be processed by any desirable techniques. Optionally, the processing steps can be used to prepare rolled aluminum alloy products, such as aluminum alloy sheets. Example optional processing steps include, but are not limited to, homogenization, hot rolling, cold rolling, annealing, solution heat treatment, stretching, and over-aging.

[0042] In a homogenization step, a cast product may be heated to a temperature ranging from about 400° C. to about 500° C. For example, the cast product can be heated to a temperature of about 400° C., about 410° C., about 420° C., about 430° C., about 440° C., about 450° C., about 460° C., about 470° C., about 480° C., about 490° C., or about 500° C. The product may then be allowed to soak (e.g., held at the indicated temperature) for a period of time to form a homogenized product up to 50 hours, such as up to 20 hours. For example, the product can be heated up to 400° C. to 500° C., and soaked, for a total time of up to 24 hours for the homogenization step.

[0043] Following a homogenization step, a hot rolling step can be optionally performed. Prior to the start of hot rolling, the homogenized product can be allowed to cool to a temperature between 300° C. to 450° C. Alternatively, the homogenized product can be cooled down to room temperature and heated up again in a separate pre-heat prior to hot rolling to a temperature between 300° C. and 450° C. For example, the homogenized product can be allowed to cool-down or pre-heated to a temperature of between 325° C. to 425° C. or from 350° C. to 400° C. The homogenized product can then be hot rolled at a temperature between 300° C. to 450° C. to form a hot rolled plate, a hot rolled shate or a hot rolled sheet having a gauge between 10 mm and 100 mm (e.g., 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm, 50 mm, 55 mm, 60 mm, 65 mm, 70 mm, 75 mm, 80 mm, 85 mm, 90 mm, 95 mm, 100 mm, or anywhere in between).

[0044] Optionally, the cast product can be a continuously cast product that can be allowed to cool to a temperature between 300° C. to 450° C. For example, the continuously cast product can be allowed to cool to a temperature of between 325° C. to 425° C. or from 350° C. to 400° C. The continuously cast products can then be hot rolled at a temperature between 300° C. to 450° C. to form a hot rolled plate, a hot rolled shate or a hot rolled sheet having a gauge between 10 mm and 100 mm (e.g., 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm, 50 mm, 55 mm, 60 mm, 65 mm, 70 mm, 75 mm, 80 mm, 85 mm, 90 mm, 95 mm, 100 mm, or anywhere in between). During hot rolling, temperatures and other operating parameters can be controlled so that the temperature of the hot rolled intermediate product upon exit from the hot rolling mill is no more than 470° C., no more than 450° C., no more than 440° C., or no more than 430° C.

[0045] Subsequently, a cast, homogenized, or rolled product can optionally undergo a solution heat treatment step. The solution heat treatment step can be any suitable treatment for the product that results in solutionizing of soluble particles. The cast, homogenized, or rolled product can be heated to a peak metal temperature (PMT) of up to 500° C. (e.g., from 400° C. to 500° C.) and soaked for a period of time at the PMT to form a hot product. For example, the cast, homogenized, or rolled product can be soaked at 480° C. for a soak time of up to 180 minutes (e.g., 0 seconds, 60 seconds, 75 seconds, 90 seconds, 5 minutes, 10 minutes, 20 minutes, 25 minutes, 30 minutes, 35 minutes, 40 minutes, 45 minutes, 50 minutes, 55 minutes, 60 minutes, 65 minutes, 70 minutes, 75 minutes, 80 minutes, 85 minutes, 90 minutes, 95 minutes, 100 minutes, 110 minutes, 120 minutes, 130 minutes, 140 minutes, 150 minutes, 160 minutes, 170 minutes, 180 minutes, or anywhere in between). After heating and soaking, the hot product is rapidly cooled at to a temperature below 90° C., or to ambient temperature, to prevent or minimize the uncontrolled precipitation of secondary phases, e.g., Al2CuMg and Al2Cu, and / or MgZn2. In one example, the hot product is cooled at a quench rate of between 2° C. / sec to 5° C. / sec at temperatures below 90° C. Optionally, the cooling rates can be faster in other cases. Optionally, the temperature can be lower in other cases.

[0046] Following the solution heat treating, the product can optionally undergo further cold working steps, for example, by stretching in the range of up to about 6% to relieve residual stresses therein and to improve the flatness of the plate product. For example, the product can be stretched in the range of about 1% to about 6%, such as from 1% to 2%, from 2% to 3%, from 3% to 4%, from 4% to 5%, or from 5% to 6%.

[0047] After quenching, the heat-treated product can undergo an over-aging treatment, such as by heating in a batch furnace. In some examples, the over-aging treatment can be performed in at least two steps to achieve the combination of properties. The over-aging treatment can be performed in a first step at a temperature of from about 110° C. to about 130° C. for a period of time of from 4 hours to 12 hours. For example, the temperature of the first step can be from 110° C. to 115° C., from 115° C. to 120° C., from 120° C. to 125° C., or from 125° C. to 130° C. In some examples, the aging period for the first step may be from 4 hours to 4.5 hours, from 4.5 hours to 5 hours, from 5 hours to 5.5 hours, from 5.5 hours to 6 hours, from 6 hours to 6.5 hours, from 6.5 hours to 7 hours, from 7 hours to 7.5 hours, from 7.5 hours to 8 hours, from 8 hours to 8.5 hours, from 8.5 hours to 9 hours, from 9 hours to 9.5 hours, from 9.5 hours to 10 hours, from 10 hours to 10.5 hours, from 10.5 hours to 11 hours, from 11 hours to 11.5 hours, or from 11.5 hours to 12 hours.

[0048] Following the first step, a second over-aging step may be performed by heating the product to a second temperature of from 160° C. to 200° C. for a second duration of from 4 hours to 40 hours. For example, the temperature of the second step can be from 160° C. to 165° C., from 165° C. to 170° C., from 170° C. to 175° C., from 175° C. to 180° C., from 180° C. to 185° C., from 185° C. to 190° C., from 190° C. to 195° C., or from 195° C. to 200° C. In some examples, the aging period for the second step may be from 4 hours to 8 hours, from 8 hours to 12 hours, from 12 hours to 16 hours, from 16 hours to 20 hours, from 20 hours to 24 hours, from 24 hours to 28 hours, from 28 hours to 32 hours, from 32 hours to 36 hours, or from 36 hours to 40 hours.

[0049] The cast products described herein can be used to make products in the form of sheets, plates, or other suitable products. For example, plates including the products as described herein can be prepared by processing an ingot in a homogenization step or casting a product in a continuous caster followed by a hot rolling step. In the hot rolling step, the cast product can be hot rolled to a 200 mm thick gauge or less (e.g., from about 10 mm to about 200 mm). For example, the cast product can be hot rolled to a plate having a final gauge thickness of about 10 mm to about 175 mm, about 15 mm to about 150 mm, about 20 mm to about 125 mm, about 25 mm to about 100 mm, about 30 mm to about 75 mm, or about 35 mm to about 50 mm. In some cases, plates may be rolled into thinner metal products, such as sheets.Methods of Using the Disclosed Aluminum Alloy Products

[0050] The aluminum alloy products described herein can be used in civil and military applications such as armor plates for vehicles. For example, the disclosed aluminum alloy products can be used to prepare panels or plates for the side and / or underbelly of vehicles. In some examples, the armor plates may be mounted on any portion of the vehicle such that the plate may protect the occupants from threats. In some examples, the aluminum alloy products described herein may meet the minimum requirements for a mechanical or ballistic requirement (e.g., a Type B requirement) of a U.S. military specification MIL-DTL-32375B or MIL-DTL-32375C.

[0051] In other examples, the aluminum alloy products described herein can be used in automotive applications and other transportation applications, including aircraft and railway applications. For example, the disclosed aluminum alloy products can be used to prepare automotive structural parts, such as bumpers, side beams, roof beams, cross beams, pillar reinforcements (e.g., A-pillars, B-pillars, and C-pillars), inner panels, outer panels, side panels, inner hoods, outer hoods, or trunk lid panels. The aluminum alloy products and methods described herein can also be used in aircraft or railway vehicle applications, to prepare, for example, external and internal panels.Methods of Treating Metals and Metal Alloys

[0052] Described herein are methods of treating metals and metal alloys, including aluminum and aluminum alloys, and the resultant treated metals and metal alloys. In some examples, the metals for use in the methods described herein include aluminum alloys, for example, 7xxx series aluminum alloys.

[0053] Non-limiting exemplary 7xxx series aluminum alloys for use in the methods described herein can include AA7011, AA7019, AA7020, AA7021, AA7039, AA7072, AA7075, AA7085, AA7108, AA7108A, AA7015, AA7017, AA7018, AA7019A, AA7024, AA7025, AA7028, AA7030, AA7031, AA7033, AA7035, AA7035A, AA7046, AA7046A, AA7003, AA7004, AA7005, AA7009, AA7010, AA7011, AA7012, AA7014, AA7016, AA7116, AA7122, AA7023, AA7026, AA7029, AA7129, AA7229, AA7032, AA7033, AA7034, AA7036, AA7136, AA7037, AA7040, AA7140, AA7041, AA7049, AA7049A, AA7149, AA7204, AA7249, AA7349, AA7449, AA7050, AA7050A, AA7150, AA7250, AA7055, AA7155, AA7255, AA7056, AA7060, AA7064, AA7065, AA7068, AA7168, AA7175, AA7475, AA7076, AA7178, AA7278, AA7278A, AA7081, AA7181, AA7185, AA7090, AA7093, AA7095, or AA7099.

[0054] The examples disclosed herein will serve to further illustrate aspects of the invention without, at the same time, however, constituting any limitation thereof. On the contrary, it is to be clearly understood that resort may be had to various embodiments, modifications and equivalents thereof which, after reading the description herein, may suggest themselves to those skilled in the art without departing from the spirit of the invention. The examples and embodiments described herein may also make use of conventional procedures, unless otherwise stated. Some of the procedures are described herein for illustrative purposes.Example 1

[0055] A series of tests were performed to evaluate the properties of 7xxx series aluminum alloy products prepared and subjected to the stretching and multi-step over-aging as described herein. Initial tests were performed on aluminum alloy products having different thicknesses, such as to evaluate compliance with the US military standard MIL-DTL-32375B or MIL-DTL-32375C. The aluminum alloy plates had nominal compositions in the range of (in wt. %) of 7.37-7.46% Zn, 1.98-2.02% Mg, 1.52-1.58% Cu, 0.12% Zr, 0.03% Ti, 0.06-0.08% Fe, 0.03-0.04% Si, <0.01% Mn, balance aluminum and unavoidable impurities. The manufacturing process included DC casting of rolling ingots, homogenizing the ingot, hot rolling the homogenized ingot, solution heat treating the plates at about 470° C., quenching, stretching of the plates by about 2.5% to arrive at final thickness, and artificial over-ageing of the stretched plate as described below.

[0056] Initial tests were performed to test the aluminum alloy products produced according to the methods described herein (e.g., 2-step over-aging with a first temperature of 120° C. for 5 hours followed by a second temperature of 170° C. for 15 hours) in accordance with the US military standard MIL-DTL-32375B (MR) (2021) or MIL-DTL-32375C (MR) (2023). The results are listed in Table 2, below.

[0057] In accordance with this standard, Cal. 30 armor piercing (AP M2) projectiles at both 0 degrees and 30 degrees, Cal. 50 fragment simulating projectile (FSP) projectiles, and 20 mm FSP projectiles were used for ballistic testing.TABLE 2Ballistic properties of plates with respect to various thicknesses.MeasuredMin. V50 acc.thicknessTo MILV50Sample(inch)ProjectileType B(fps)1A0.497Cal. 30 AP M2 30 Deg152415621B0.676Cal. 30 AP M2 30 Deg184219481C0.750Cal. 30 AP M2 30 Deg195821080.746Cal 30 AP M2181119020.746Cal 50 FSP191619521D0.980Cal. 30 AP M2213022310.980Cal 50 FSP301632181E0.99520 mm FSP136414580.995Cal. 30 AP M2214922341F1.24720 mm FSP188520651.247Cal. 30 AP M224442533

[0058] These results demonstrate that the over-aging process described herein may be used for production of armor components produced from the 7xxx series aluminum alloys described herein to achieve an armor piercing V50 ballistic limits described by MIL-DTL-32375B. The results from Table 2 are summarized in FIG. 2. The target values as set forth in the MIL-DTL-32375B are shown as a solid line while the filled triangles are the V50 velocities measured. The measured V50 velocities exceeded the target values at the thickness ranges tested according to the ML-DTL-32375B for Type B.

[0059] Experiments were performed on the example samples from the 0.75-inch aluminum alloy products to evaluate the ballistic properties under altered processing techniques. Specifically, the samples were produced to a final thickness of 0.75 inches and were processed via alternate over-aging conditions. The over-aging conditions included a first aging step at a temperature of 120° C. for 8 hours and a second aging step including a temperature of 170° C. for 13 hours and 11 hours respectively. The results are shown in Table 3.TABLE 3Ballistic properties of plates with respect to varied heat treatments.MeasuredMin. V50 acc.Over-agingthicknessto MIL-DTL-V50Process(inch)Projectile32375B(fps)120° C. (80.748Cal. 30 AP M2 30 Deg19552072h), 170° C.0.749Cal. 30 AP M2 0 Deg18151903(13 h)0.749Cal 50 FSP19281972120° C. (50.748Cal. 30 AP M2 30 Deg19552012h), 170° C.0.750Cal. 30 AP M2 0 Deg18161930(11 h)0.750Cal 50 FSP19311947

[0060] For samples produced under reduced aging times (e.g., a second aging step of 170° C. at either 13 hours or 11 hours), the measurements are generally consistent with that of the second over-aging step of 170° C. for 15 h. The samples tested passed the ballistic testing with their V50 exceeding the minimum requirements as set by the US MIL-DTS-32375B Type B standard. Thus, the results demonstrate the over-aging temperature above traditional temperature ranges in the second over-aging step may lead to improved characteristics not previously seen in 7xxx series aluminum alloys.

[0061] Additional testing was performed such as mechanical properties of the 7xxx series aluminum alloy product (over-aging included a first temperature of 120° C. for 5 hours followed by a second temperature of 170° C. for 15 hours). FIG. 3 compares the mechanical properties in the long transverse (LT) direction with the graph representing the mean values and three times standard deviation calculated from two tensile tests per sample. The target yield strength (Rp 0.2), tensile strength (Rm), and elongation (A) are shown as solid lines, while the mean values are represented by the diamonds. The values measured are higher than the minimum requirements for MIL-DTL-32375 Type B Class I. For example, the sample at 0.500 inches had a target Rp 0.2 of below 420 MPa with the actual Rp 0.2 measured at greater than 440 MPa. The Rm target value was about 470 MPa with the lowest Rm value recorded from the 0.750-inch sample being measured at greater than 500 MPA. The results demonstrate that the process described herein generates products with superior mechanical properties, in some cases in excess of the military specification.

[0062] Subsequent tests were conducted on plates produced from 7xxx series aluminum alloys and subjected to the 2-step over-aging process where the metal was over-aged including a first aging step including a temperature of 120° C. for 5 hours and a second aging step including a temperature of 170° C. for 15 hours. The samples were subsequently tested for corrosion resistance according to ASTM-G34. A visual rating is assigned to a sample according to the degree of corrosion on the sample. For example, an N rating is indicated by no visible attack on the sample, a P rating is indicative of pitting in the sample, and an exfoliation rating is assigned (EA through ED) depending on the degree of exfoliation. Superficial exfoliation is denoted as EA, while EB is indicative of Moderate, EC denotes severe, and ED denotes very severe (the loss of metal is greater, and the depth of exfoliation is increased).TABLE 4Exfoliation corrosion according to ASTM-G34.Thickness (mm)Tested SurfaceResult12.70s / 10EASample SurfaceEA31.75s / 10EASample SurfaceEA15.80s / 10EASample SurfaceEA24.00s / 10EASample SurfaceEA19.00s / 10EASample SurfaceEA

[0063] Testing for stress corrosion cracking (SCC) were conducted in accordance with the Standard Test Method for Determining Stress-Corrosion Cracking Resistance of Heat-Treatable Aluminum Alloy Products using Breaking Load Method, ASTM International, West Conshohocken, PA, 2015, or ASTM G64 with the results shown below in Table 5. The plates produced from the 7xxx series aluminum alloy and methods described herein demonstrated extraordinary good SCC resistance. For example, all samples passed SCC testing after 40 days of exposure. After 40 days of testing without any failure, the test was aborted. The results indicate that that the 7xxx aluminum alloy processed as described herein has excellent corrosion properties. It also meets and exceeds the mechanical and ballistic requirements according to MIL-DTL-32375B and / or MIL-DTL-32375C. This makes the 7xxx aluminum alloy processed as described herein a very corrosion resistant, mine blast resistant alloy suitable for use on vehicles to protect the occupants from underbody threats.TABLE 5SCC testing for samples at various thicknesses.YieldThicknessstrength(mm)(MPa)2 day4 day10 day20 day30 day40 day31.75311OKOKOKOKOKOK31.75OKOKOKOKOKOK31.75OKOKOKOKOKOK24.13311OKOKOKOKOKOK24.13OKOKOKOKOKOK24.13OKOKOKOKOKOK19.05311OKOKOKOKOKOK19.05OKOKOKOKOKOK19.05OKOKOKOKOKOK

[0064] FIG. 4 provides a graph of the absorbed impact energy in J / cm2 for samples processed as described herein at various thicknesses. The impact energy measurements were conducted according to the EN ISO 148-1 in LS direction using a 2 mm v-notch. In general, the absorbed energy was very high, with values above 50 J / cm2, for example. The results indicate that the samples are very ductile and thus are highly suited for mine blast applications.ILLUSTRATIVE ASPECTS

[0065] As used below, any reference to a series of aspects (e.g., “Aspects 1-4”) or non-enumerated group of aspects (e.g., “any previous or subsequent aspect”) is to be understood as a reference to each of those aspects disjunctively (e.g., “Aspects 1-4” is to be understood as “Aspects 1, 2, 3, or 4”).

[0066] Aspect 1 is an armor component comprising a metal product, the metal product comprising a 7xxx series aluminum alloy, wherein the metal product exhibits a yield strength of from about 400 MPa to 495 MPa, wherein the metal product exhibits an ultimate tensile strength of from about 450 MPa to 545 MPa, wherein the metal product exhibits an elongation of about 9% to 16%, and wherein the 7xxx series aluminum alloy comprises: about 7.1 wt. % to 7.5 wt. % Zn, about 1.90 wt. % to 2.25 wt. % Mg, about 1.3 wt. % to 1.8 wt. % Cu, about 0.05 wt. % to 0.4 wt. % of a dispersoid forming element, about 0.01 wt. % to 0.06 wt. % Ti, up to about 0.15 wt. % Si, up to 0.15 wt. % Fe, and Al.

[0067] Aspect 2 is the armor component of any previous or subsequent aspect, wherein the metal product exhibits an absorbed impact energy of from 40 J / cm2 to 100 J / cm2.

[0068] Aspect 3 is the armor component of any previous or subsequent aspect, wherein the yield strength is from about 410 MPa to about 470 MPa, wherein the ultimate tensile strength is from about 470 MPa to about 530 MPa, and the elongation is from about 12% to 16%.

[0069] Aspect 4 is the armor component of any previous or subsequent aspect, wherein the metal product exhibits ballistic properties that meets a US military specification, or wherein the metal product meets Type B mechanical and ballistic requirements of a US military specification.

[0070] Aspect 5 is the armor component of any previous or subsequent aspect, wherein the US military specification is a MIL-DTL-32375B specification or a MIL-DTL-32375C specification.

[0071] Aspect 6 is the armor component of any previous or subsequent aspect, wherein the metal product exhibits an exfoliation corrosion susceptibility of EA or EB according to an ASTM G34 standard.

[0072] Aspect 7 is the armor component of any previous or subsequent aspect, wherein the metal product exhibits a stress-corrosion cracking resistance of at least 30 days according to an ASTM G64 standard.

[0073] Aspect 8 is the armor component of any previous or subsequent aspect, wherein the yield strength is along a LT direction, wherein the ultimate tensile strength is along a LT direction, and wherein the elongation is along a LT direction.

[0074] Aspect 9 is the armor component of any previous or subsequent aspect, wherein the dispersoid forming element comprises one or more of Zr, Sc, V, Hf, Ti, Cr, or Mn.

[0075] Aspect 10 is the armor component of any previous or subsequent aspect, wherein the metal product is a plate having a thickness of from 12.7 mm to 76.2 mm.

[0076] Aspect 11 is the armor component of any previous or subsequent aspect, wherein the 7xxx series aluminum alloy comprises a ratio of Zn to Mg of less than or about 4.

[0077] Aspect 12 is the armor component of any previous or subsequent aspect, wherein the dispersoid forming element comprises Zr in a range of from 0.06 wt. % to 0.15 wt. %.

[0078] Aspect 13 is the armor component of any previous or subsequent aspect, wherein the 7xxx series aluminum alloy comprises impurities of up to 0.15 wt. % and a balance Al.

[0079] Aspect 14 is the armor component of any previous or subsequent aspect, having been subjected to an over-aging treatment comprising heating to a first temperature of from 110° C. to 130° C. for a first duration of from 4 hours to 12 hours and followed by heating to a second temperature of from 160° C. to 200° C. for a second duration of from 4 hours to 40 hours.

[0080] Aspect 15 is the armor component of any previous aspect, wherein the second duration is from 10 hours to 18 hours.

[0081] Aspect 16 is a method of producing an armor component, the method comprising: casting a 7xxx series aluminum alloy into an ingot; homogenizing the ingot; hot rolling the ingot to obtain a metal product; solution heat treating the metal product; quenching the metal product; stretching the metal product to obtain a permanent elongation from 1% to 6%; and subjecting the metal product to an over-aging treatment, wherein the over-aging treatment comprises heating the metal product to a first temperature of from 110° C. to 130° C. for a first duration of from 4 hours to 12 hours and followed by heating the metal product to a second temperature of from 160° C. to 200° C. for a second duration of from 4 hours to 40 hours, wherein the metal product exhibits a yield strength of from about 400 MPa to 495 MPa, wherein the metal product exhibits an ultimate tensile strength of from about 450 MPa to 545 MPa, wherein the metal product exhibits an elongation of about 9% to 16%, and wherein the 7xxx series aluminum alloy comprises: about 7.1 wt. % to 7.5 wt. % Zn, about 1.90 wt. % to 2.25 wt. % Mg, about 1.3 wt. % to 1.8 wt. % Cu, about 0.05 wt. % to 0.4 wt. % of a dispersoid forming element, about 0.01 wt. % to 0.06 wt. % Ti, up to about 0.15 wt. % Si, up to 0.15 wt. % Fe, and Al.

[0082] Aspect 17 is the method of any previous or subsequent aspect, further comprising cold rolling the metal product.

[0083] Aspect 18 is the method of any previous or subsequent aspect, wherein the over-aging treatment generates a microstructure in the metal product providing the yield strength, the ultimate tensile strength, and the elongation.

[0084] Aspect 19 is the method of any previous or subsequent aspect, wherein the second duration is from 10 hours to 18 hours.

[0085] Aspect 20 is the method of any previous or subsequent aspect, wherein the metal product exhibits ballistic properties that meets a US military specification, or wherein the metal product meets Type B mechanical and ballistic requirements of a US military specification.

[0086] Aspect 21 is the method of any previous or subsequent aspect, wherein the US military specification is a MIL-DTL-32375B specification or a MIL-DTL-32375C specification.

[0087] Aspect 22 is the method of any previous aspect, wherein the armor component is the armor component of any previous aspect.

[0088] All patents and publications cited herein are incorporated by reference in their entirety. The foregoing description of the examples and embodiments, including illustrated embodiments and aspects, has been presented only for the purpose of illustration and description and is not intended to be exhaustive or limiting to the precise forms disclosed. Numerous modifications, adaptations, and uses thereof will be apparent to those skilled in the art.

Claims

1. An armor component comprising a metal product, the metal product comprising a 7xxx series aluminum alloy, wherein the metal product exhibits a yield strength of from about 400 MPa to 495 MPa, wherein the metal product exhibits an ultimate tensile strength of from about 450 MPa to 545 MPa, wherein the metal product exhibits an elongation of about 9% to 16%, and wherein the 7xxx series aluminum alloy comprises:about 7.1 wt. % to 7.5 wt. % Zn,about 1.90 wt. % to 2.25 wt. % Mg,about 1.3 wt. % to 1.8 wt. % Cu,about 0.05 wt. % to 0.4 wt. % of a dispersoid forming element,about 0.01 wt. % to 0.06 wt. % Ti,up to about 0.15 wt. % Si,up to 0.15 wt. % Fe, andAl.

2. The armor component of claim 1, wherein the metal product exhibits an absorbed impact energy of from 40 J / cm2 to 100 J / cm2.

3. The armor component of claim 1, wherein the yield strength is from about 410 MPa to about 470 MPa, wherein the ultimate tensile strength is from about 470 MPa to about 530 MPa, and the elongation is from about 12% to 16%.

4. The armor component of claim 1, wherein the metal product exhibits ballistic properties that meets a US military specification, or wherein the metal product meets Type B mechanical and ballistic requirements of a US military specification.

5. The armor component of claim 4, wherein the US military specification is a MIL-DTL-32375B specification or a MIL-DTL-32375C specification.

6. The armor component of claim 1, wherein the metal product exhibits an exfoliation corrosion susceptibility of EA or EB according to an ASTM G34 standard.

7. The armor component of claim 1, wherein the metal product exhibits a stress-corrosion cracking resistance of at least 30 days according to an ASTM G64 standard.

8. The armor component of claim 1, wherein the yield strength is along a LT direction, wherein the ultimate tensile strength is along a LT direction, and wherein the elongation is along a LT direction.

9. The armor component of claim 1, wherein the dispersoid forming element comprises one or more of Zr, Sc, V, Hf, Ti, Cr, or Mn.

10. The armor component of claim 1, wherein the metal product is a plate having a thickness of from 12.7 mm to 76.2 mm.

11. The armor component of claim 1, wherein the 7xxx series aluminum alloy comprises a ratio of Zn to Mg of less than or about 4.

12. The armor component of claim 1, wherein the dispersoid forming element comprises Zr in a range of from 0.06 wt. % to 0.15 wt. %.

13. The armor component of claim 1, wherein the 7xxx series aluminum alloy comprises impurities of up to 0.15 wt. % and a balance Al.

14. The armor component of claim 1, having been subjected to an over-aging treatment comprising heating to a first temperature of from 110° C. to 130° C. for a first duration of from 4 hours to 12 hours, and followed by heating to a second temperature of from 160° C. to 200° C. for a second duration of from 4 hours to 40 hours.

15. The armor component of claim 1, wherein the second duration is from 10 hours to 18 hours.

16. A method of producing an armor component, the method comprising:casting a 7xxx series aluminum alloy into an ingot;homogenizing the ingot;hot rolling the ingot to obtain a metal product;solution heat treating the metal product;quenching the metal product;stretching the metal product to obtain a permanent elongation from 1% to 6%; andsubjecting the metal product to an over-aging treatment, wherein the over-aging treatment comprises heating the metal product to a first temperature of from 110° C. to 130° C. for a first duration of from 4 hours to 12 hours and followed by heating the metal product to a second temperature of from 160° C. to 200° C. for a second duration of from 4 hours to 40 hours,wherein the metal product exhibits a yield strength of from about 400 MPa to 495 MPa, wherein the metal product exhibits an ultimate tensile strength of from about 450 MPa to 545 MPa, wherein the metal product exhibits an elongation of about 9% to 16%, and wherein the 7xxx series aluminum alloy comprises:about 7.1 wt. % to 7.5 wt. % Zn,about 1.90 wt. % to 2.25 wt. % Mg,about 1.3 wt. % to 1.8 wt. % Cu,about 0.05 wt. % to 0.4 wt. % of a dispersoid forming element,about 0.01 wt. % to 0.06 wt. % Ti,up to about 0.15 wt. % Si,up to 0.15 wt. % Fe, andAl.

17. The method of claim 16, further comprising cold rolling the metal product.

18. The method of claim 16, wherein the over-aging treatment generates a microstructure in the metal product providing the yield strength, the ultimate tensile strength, and the elongation.

19. The method of claim 16, wherein the second duration is from 10 hours to 18 hours.

20. The method of claim 16, wherein the metal product exhibits ballistic properties that meets a US military specification, or wherein the metal product meets Type B mechanical and ballistic requirements of a US military specification.21-22. (canceled)

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