Aluminum alloy articles exhibiting improved bonding durability and methods for producing the same

Abstract

Metal articles and methods of making and treating such metal articles are disclosed. More specifically, aluminum alloy articles are disclosed that exhibit controllable surface properties, including excellent bond durability. The aluminum alloy articles described herein include a surface having a concentration of alloying elements and a coating having a concentration of elements capable of interacting with the alloying elements. Also disclosed herein are methods of providing metal articles with excellent bond durability.

Description

[Technical Field]

[0001] Cross-reference of related applications This application claims priority and benefit of U.S. Provisional Patent Application No. 62 / 991,317, filed on 18 March 2020 (which is incorporated herein by reference in its entirety).

[0002] This disclosure relates to aluminum alloy articles and their surface characteristics. This disclosure further relates to a method for pre-treating aluminum alloy articles. [Background technology]

[0003] Aluminum alloy articles are often bonded or joined to other metals or alloys, including other aluminum alloys, during the manufacture of aluminum alloy articles and other metal articles. Requirements for these articles include, for example, good bond durability and high resistance to harsh environmental conditions. Aluminum alloy articles can be pre-treated to enhance bond durability. [Overview of the project]

[0004] The embodiments included in this invention are defined by the claims, not by this summary. This summary is a higher-level overview of the various aspects of the invention and introduces some of the concepts that will be further described in the sections on embodiments for carrying out the invention below. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used alone to determine the scope of the claimed subject matter. The subject matter should be understood by referring to the entire specification, some or all of the drawings, and the appropriate parts of each claim.

[0005] Provided herein is a pre-treated metal article comprising a first surface portion containing excess silicon (Si); and a surface pretreatment layer containing one or more Si-containing compounds, wherein either the first surface portion or one or more Si-containing compounds contains oxygen (O), and a silicon-oxygen-silicon (Si-O-Si) bond interaction exists between the excess Si present in the first surface portion and the one or more Si-containing compounds present in the surface pretreatment layer, and the surface pretreatment layer is attached to the first surface portion. In certain embodiments, the excess Si is present in the first surface portion in an amount greater than about 1.4% by weight.

[0006] Optionally, the pre-treated metal article includes aluminum or aluminum alloys, steel, magnesium or magnesium alloys, titanium or titanium alloys, copper or copper alloys, any suitable metal or metal alloy, or any combination thereof. In some cases, the pre-treated metal article includes aluminum alloys (e.g., 4xxx series aluminum alloys, 5xxx series aluminum alloys, or 6xxx series aluminum alloys). In certain embodiments, the Si-containing compound is silicon-oxygen (SiO2). x ) containing a portion, where x is an integer in the range of 1 to 4 (e.g., 1, 2, 3, or 4). The pre-treated metal articles may optionally be automotive structural components, aerospace structural components, transport structural components, automotive body components, aerospace skin panels, transport body components, building components, aesthetic components, electronic device housings, or beverage or food containers.

[0007] The Specified Method also provides a method for joining a first metal to a second metal, the method comprising: providing a first metal having a first surface portion containing excess Si; applying a surface pretreatment layer containing one or more Si-containing compounds to the first surface portion of the first metal to form a pretreated surface portion of the first metal, wherein either the first surface portion of the first metal or one or more Si-containing compounds contains O, and the application stimulates Si-O-Si bond interactions between the excess Si present in the first surface portion of the first metal and the one or more Si-containing compounds present in the surface pretreatment layer; and joining the pretreated surface portion of the first metal to the surface of the second metal. In some cases, one or more of the following conditions (a) to (c) are met: (a) the bond durability between the pre-treated surface portion of the first metal and the surface of the second metal is greater than the bond durability between the surface portion of the metal pre-treated with a surface pre-treatment that contains excess Si but does not contain one or more Si-containing compounds and (ii) the second metal; (b) the bond durability between the pre-treated surface portion of the first metal and the surface of the second metal is greater than the bond durability between the surface portion of the metal pre-treated with a surface pre-treatment that does not contain excess Si but contains one or more Si-containing compounds and (ii) the second metal; or (c) the bond durability between the pre-treated surface portion of the first metal and the surface of the second metal is greater than the bond durability between the surface portion of the metal pre-treated with a surface pre-treatment that does not contain excess Si and does not contain one or more Si-containing compounds and (ii) the second metal.

[0008] The first metal may optionally be aluminum or an aluminum alloy, steel, magnesium or a magnesium alloy, titanium or a titanium alloy, copper or a copper alloy, any suitable metal or metal alloy, or any combination thereof. Optionally, the first metal is an aluminum alloy. In certain embodiments, the aluminum alloy may be a 4xxx series aluminum alloy, a 5xxx series aluminum alloy, or a 6xxx series aluminum alloy. Optionally, the second metal may optionally be aluminum or an aluminum alloy, steel, magnesium or a magnesium alloy, titanium or a titanium alloy, copper or a copper alloy, any suitable metal or metal alloy, or any combination thereof. In some examples, the first surface portion of the first metal contains an excess of Si in an amount greater than approximately 1.4% by weight.

[0009] The methods described herein may further include etching at least a first surface portion of the first metal prior to the application step, wherein the etching of at least a first surface portion of the metal is performed at a maximum rate of approximately 3 grams / square meter (g / m²). 2 The Si in the first surface portion can be exposed by removing the surface material of the first metal. The methods described herein may further include cleaning at least the first surface portion of the first metal before application. Cleaning at least the first surface portion of the first metal can remove natural oxide or hydroxide species from the first surface portion of the first metal. In some cases, applying the surface pretreatment layer to the first surface portion of the first metal includes bar coating, roll coating, spray coating, or dip coating, and curing of the surface pretreatment.

[0010] A bonded metal structure prepared according to the method described herein is further provided herein, the bond strength of which the bonded metal structure experiences a bond strength loss of less than 40% after 20 weeks of exposure to a neutral salt spray test.

[0011] Further embodiments, purposes, and advantages will become apparent with reference to subsequent embodiments and drawings for carrying out the invention. [Brief explanation of the drawing]

[0012] [Figure 1] This graph shows the initial bond strength and bond strength loss in megapascals (MPa) at 0, 2, 6, 12, and 20 weeks for aluminum alloy samples tested in adhesive bonding tests. [Figure 2] A to E are digital images of the adhesion test results at week 0 (A), week 2 (B), week 6 (C), week 12 (D), and week 20 (E) for aluminum alloy samples containing excess Si and pre-treated with a Si-containing compound. [Figure 3] A to E are digital images of the adhesion test results at week 0 (A), week 2 (B), week 6 (C), week 12 (D), and week 20 (E) for aluminum alloy samples containing excess Si and pre-treated with a Si-containing compound. [Figure 4] Images A through D are digital images of the adhesion test results at week 0 (A), week 6 (B), week 12 (C), and week 20 (D) for aluminum alloy samples containing excess Si and pre-treated with titanium zirconium (TiZr). [Figure 5] Images A through D are digital images of the adhesion test results at week 0 (A), week 6 (B), week 12 (C), and week 20 (D) for aluminum alloy samples containing excess Si and pre-treated with titanium zirconium (TiZr). [Modes for carrying out the invention]

[0013] Methods for preparing pre-treated and joined metal articles are described herein, including aluminum alloy articles having desirable bond durability properties. In some non-limiting examples, the metal articles described herein have a certain concentration of alloying elements, e.g., Si, which constitutes at least a portion of the surface of the metal article after a surface etching process, a surface cleaning process, a heat treatment process, a hot working process, a cold working process, a warm working process, any suitable metallurgical process that can cause Si migration from the bulk metal to the metal surface, or any combination thereof. In certain examples, Si migration from the bulk metal to the metal surface increases the Si content on the metal surface by at least an order of magnitude. One or more surfaces of the metal article are coated with Si-containing compounds (e.g., SiO₂). x The surface can be coated with a surface pretreatment layer containing a Si-containing compound (which contains a portion of the Si). In some cases, a certain concentration of Si over at least a portion of the surface of the metal article can provide desirable bond durability after the Si-based pretreatment layer is applied to the surface of the metal article. Contact between the surface of the metal article and the pretreatment layer stimulates Si-O-Si bond interactions between the Si-containing compound in the surface of the metal article and the Si-containing compound in the pretreatment layer. In some cases, the Si in the surface of the metal article (e.g., excess Si in the metal article described below) stimulates Si-O-Si bond interactions between O atoms in the pretreatment layer (e.g., SiO x It can interact with (parts) and provide Si-O-Si interactions. For example, Si atoms on the surface of a metal article can interact with SiO in the pre-treatment layer. x It can interact with parts. In certain cases, Si-O-Si bond interactions arise from the Si content on the metal surface (e.g., excess Si in the metal article described below), metal oxides on the metal surface (e.g., aluminum oxide (Al2O3)), and Si-containing compounds in the pretreatment layer. In some examples, excess Si on the surface of the metal article can interact with O atoms on the surface of the metal article (e.g., Al2O3) and / or O atoms in the pretreatment layer (e.g., SiO2O3). xIn other embodiments, excess Si in the surface of a metal article can interact with O atoms in the surface of the metal article (e.g., metal oxides (e.g., Al2O3), O atoms in the metal lattice, excess Si that is at least partially oxidized, O present in Si-containing compounds in alloys, other O-containing compounds in alloys, etc.) and Si atoms in the pre-treatment layer (e.g., Si atoms or SiO x It can interact with a portion of the body to provide a Si-O-Si interaction.

[0014] Definition and Description As used herein, the terms “invention,” “the invention,” “this invention,” and “the present invention” are intended to broadly refer to all the subject matter of this patent application and the following claims. It should be understood that any statements containing these terms do not limit the subject matter described herein or the meaning or scope of the following claims.

[0015] This description refers to alloys identified by aluminum industry designations such as "system" or "AA4xxx". For an understanding of the most commonly used numbering system for naming and identifying aluminum and its alloys, please refer to "International Alloy Designations and Chemical Composition Limits for Wrought Aluminum and Wrought Aluminum Alloys" or "Registration Record of Aluminum Association Alloy Designations and Chemical Composition Limits for Aluminum Alloys in the Form of Castings and Ingot" (both published by the Aluminum Association).

[0016] As used herein, the meanings of "a," "an," or "the" include singular and plural referents unless the context explicitly indicates otherwise.

[0017] As used herein, a plate generally has a thickness of more than approximately 15 mm. For example, a plate may refer to an aluminum article having a thickness of more than 15 mm, more than 20 mm, more than 25 mm, more than 30 mm, more than 35 mm, more than 40 mm, more than 45 mm, more than 50 mm, or more than 100 mm.

[0018] As used herein, shades (also referred to as sheet plates) generally have a thickness of approximately 4 mm to approximately 15 mm. For example, shades may have a thickness of 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, or 15 mm.

[0019] As used herein, a sheet generally refers to an aluminum article having a thickness of less than approximately 4 mm. For example, a sheet may have a thickness of less than 4 mm, less than 3 mm, less than 2 mm, less than 1 mm, less than 0.5 mm, less than 0.3 mm, or less than 0.1 mm.

[0020] This application refers to alloy tempers or grades. For an understanding of the most commonly used descriptions of alloy grades, see "American National Standards (ANSI) H35 on Alloy and Temper Designation Systems". F temper or grade refers to aluminum alloys in the as-made state. O temper or grade refers to aluminum alloys after annealing. Hxx temper or grade, also referred to herein as H grade, refers to aluminum alloys that are not heat-treatable after cold rolling, with or without heat treatment (e.g., annealing). Preferred H grades include HX1, HX2, HX3, HX4, HX5, HX6, HX7, HX8, or HX9 grades. T1 temper or grade refers to aluminum alloys that have been cooled from hot working and naturally aged (e.g., at room temperature). T2 temper or grade refers to aluminum alloys that have been cooled from hot working, cold working, and naturally aged. T3 temper or grade refers to aluminum alloys that have been solution-treated, cold-worked, and naturally aged. T4 temper or grade refers to aluminum alloys that have been solution-treated and naturally aged. T5 temper or grade refers to aluminum alloys that have been hot-worked, cooled, and artificially aged (at high temperatures). T6 temper or grade refers to aluminum alloys that have been solution-treated and artificially aged. T7 temper or grade refers to aluminum alloys that have been solution-treated and artificially over-aged. T8x temper or grade refers to aluminum alloys that have been solution-treated, cold-worked, and artificially aged. T9 temper or grade refers to aluminum alloys that have been solution-treated, artificially aged, and cold-worked.

[0021] As used herein, terms such as “cast metal articles” and “cast articles” are interchangeable and refer to articles produced by direct chill casting (including direct chill co-casting) or semi-continuous casting, continuous casting (including, for example, the use of a twin-belt caster, twin-roll caster, block caster, or any other continuous caster), electromagnetic casting, hot-top casting, or any other casting method.

[0022] As used herein, "bond durability" refers to the ability of an adhesive to join two articles together that can withstand periodic mechanical stress after exposure to environmental conditions that initiate breakdown of the adhesive. Bond durability is characterized in terms of the number of mechanical stress cycles applied to the joined articles before the bond breaks.

[0023] As used herein, "room temperature" can include temperatures from about 15°C to about 30°C, such as, 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.

[0024] It should be understood that all ranges disclosed herein include both endpoints and all subranges subsumed therein. For example, the described range "1 to 10" should be considered to include any and all subranges between the minimum value of 1 and the maximum value of 10 (and including the endpoints); that is, all subranges begin with a minimum value of 1 or more, such as, for example, starting from 1 to 6.1, and end with a maximum value of 10 or less, such as, for example, ending with 5.5 to 10.

[0025] Metal article Metal articles having desirable surface properties, including bond durability, are described herein. The metal article can include Si as a major alloying element and can include at least one surface or a portion thereof coated with a surface pretreatment that includes one or more Si-containing compounds (e.g., Si-containing compounds containing portions of SiO x In certain embodiments, the metal article can be an aluminum alloy article having one or more surfaces that contain excess Si (e.g., the excess Si is present in an amount greater than about 1.4 wt%). In some cases, the excess Si in the aluminum alloy surface is one or more SiO xIt interacts with the parts. In some cases, excess Si in the aluminum alloy surface is oxidized to form silicon dioxide, and the silicon dioxide present on the aluminum alloy surface interacts with one or more Si-containing compounds during pretreatment. Si-O-Si bond interactions increase bond durability when a metal article is bonded to at least a second metal article.

[0026] While not bound by theory, pretreatment can bond to the metal article using any preferred mechanism initiated by mechanical bonding, van der Waals forces, dipole interactions, hydrogen bonding, covalent bonding, ionic bonding, or close contact between the pretreatment and the metal article. In certain non-limiting examples, excess Si in an aluminum alloy article, including excess Si on the aluminum alloy surface, is SiO2 during pretreatment. x It can form covalent bonds in parts. The adhesion of pre-treated materials to metal articles is enhanced by utilizing the ability of Si to form Si-O-Si bonds. Therefore, Si-containing compounds (e.g., SiO x Applying a pretreatment (including a portion) to a metal article having excess Si enhances the adhesion of the pretreatment via the Si-O-Si bond interaction described above.

[0027] As used herein, the term “surface” refers to a portion of a metal article that extends from its outer surface into the interior of the metal article to a depth of up to approximately 5 μm (for example, up to approximately 0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1 μm, 2 μm, 3 μm, 4 μm, or 4.5 μm).

[0028] Optionally, the surface refers to the interior of the metal article, with thicknesses of approximately 0.01 μm, 0.02 μm, 0.03 μm, 0.04 μm, 0.05 μm, 0.06 μm, 0.07 μm, 0.08 μm, 0.09 μm, 0.1 μm, 0.11 μm, 0.12 μm, 0.13 μm, 0.14 μm, 0.15 μm, 0.16 μm, 0.17 μm, 0.18 μm, 0.19 μm, 0.2 μm, 0.21 μm, 0.22 μm, 0.23 μm, 0.24 μm, 0.25 μm, 0.26 μm, 0.27 μm, 0.28 μm, and 0.29 μm. Approx. 0.3μm, approx. 0.31μm, approx. 0.32μm, approx. 0.33μm, approx. 0.34μm, approx. 0.35μm, approx. 0.36μm, approx. 0.37μm , about 0.38μm, about 0.39μm, about 0.4μm, about 0.41μm, about 0.42μm, about 0.43μm, about 0.44μm, about 0.45μm , about 0.46μm, about 0.47μm, about 0.48μm, about 0.49μm, about 0.5μm, about 0.51μm, about 0.52μm, about 0.53μ m, approx. 0.54μm, approx. 0.55μm, approx. 0.56μm, approx. 0.57μm, approx. 0.58μm, approx. 0.59μm, approx. 0.6μm, approx. 0.61μ m, approx. 0.62 μm, approx. 0.63 μm, approx. 0.64 μm, approx. 0.65 μm, approx. 0.66 μm, approx. 0.67 μm, approx. 0.68 μm, approx. 0.6 9μm, approximately 0.7μm, approximately 0.71μm, approximately 0.72μm, approximately 0.73μm, approximately 0.74μm, approximately 0.75μm, approximately 0.76μm, approximately 0.7 7μm, approximately 0.78μm, approximately 0.79μm, approximately 0.8μm, approximately 0.81μm, approximately 0.82μm, approximately 0.83μm, approximately 0.84μm, approximately 0. 85μm, about 0.86μm, about 0.87μm, about 0.88μm, about 0.89μm, about 0.9μm, about 0.91μm, about 0.92μm, about 0. 93μm, approximately 0.94μm, approximately 0.95μm, approximately 0.96μm, approximately 0.97μm, approximately 0.98μm, approximately 0.99μm, approximately 1μm, approximately 1.01μm, approximately 1.02μm, approximately 1.03μm, approximately 1.04μm, approximately 1.05μm, approximately 1.06μm, approximately 1.07μm, approximately 1.08μm, approximately 1. 09μm, about 1.1μm, about 1.11μm, about 1.12μm, about 1.13μm, about 1.14μm, about 1.15μm, about 1.16μm, about 1. 17μm, about 1.18μm, about 1.19μm, about 1.2μm, about 1.21μm, about 1.22μm, about 1.23μm, about 1.24μm, about 1.25μm, approximately 1.26μm, approximately 1.27μm, approximately 1.28μm, approximately 1.29μm, approximately 1.3μm, approximately 1.31μm, approximately 1.32μm, approximately 1.33μm, approximately 1.34μm, approximately 1.35μm, approximately 1.36μm, approximately 1.37μm, approximately 1.38μm, approximately 1.39μm, approximately 1.4μm, approximately 1 0.41μm, approximately 1.42μm, approximately 1.43μm, approximately 1.44μm, approximately 1.45μm, approximately 1.46μm, approximately 1.47μm, approximately 1.48μm, approximately 1.49μm, approximately 1.5μm, approximately 1.51μm, approximately 1.52μm, approximately 1.53μm, approximately 1.54μm, approximately 1.55μm, approximately 1.56μm Approximately 1.57 μm, approximately 1.58 μm, approximately 1.59 μm, approximately 1.6 μm, approximately 1.61 μm, approximately 1.62 μm, approximately 1.63 μm, approximately 1.64 μm, approximately 1.65 μm, approximately 1.66 μm, approximately 1.67 μm, approximately 1.68 μm, approximately 1.69 μm, approximately 1.7 μm, approximately 1.71 μm, approximately 1.72 μm Approximately 1.73 μm, approximately 1.74 μm, approximately 1.75 μm, approximately 1.76 μm, approximately 1.77 μm, approximately 1.78 μm, approximately 1.79 μm, approximately 1.8 μm, approximately 1.81 μm, approximately 1.82 μm, approximately 1.83 μm, approximately 1.84 μm, approximately 1.85 μm, approximately 1.86 μm, approximately 1.87 μm, approximately 1.88 μm μm, approximately 1.89μm, approximately 1.9μm, approximately 1.91μm, approximately 1.92μm, approximately 1.93μm, approximately 1.94μm, approximately 1.95μm, approximately 1.96μm, approximately 1.97μm, approximately 1.98μm, approximately 1.99μm, approximately 2μm, approximately 2.01μm, approximately 2.02μm, approximately 2.03μm, approximately 2.04μm μm, approximately 2.05 μm, approximately 2.06 μm, approximately 2.07 μm, approximately 2.08 μm, approximately 2.09 μm, approximately 2.1 μm, approximately 2.11 μm, approximately 2.12 μm, approximately 2.13 μm, approximately 2.14 μm, approximately 2.15 μm, approximately 2.16 μm, approximately 2.17 μm, approximately 2.18 μm, approximately 2.19 μm, approximately 2.2 μm μm, approximately 2.21 μm, approximately 2.22 μm, approximately 2.23 μm, approximately 2.24 μm, approximately 2.25 μm, approximately 2.26 μm, approximately 2.27 μm, approximately 2.28 μm, approximately 2.29 μm, approximately 2.3 μm, approximately 2.31 μm, approximately 2.32 μm, approximately 2.33 μm, approximately 2.34 μm, approximately 2.35 μm, approximately 2. 36μm, approximately 2.37μm, approximately 2.38μm, approximately 2.39μm, approximately 2.4μm, approximately 2.41μm, approximately 2.42μm, approximately 2.43μm, approximately 2.44μm, approximately 2.45μm, approximately 2.46μm, approximately 2.47μm, approximately 2.48μm, approximately 2.49μm, approximately 2.5μm, approximately 2.51μm, approximately 2.52μm, approximately 2.53μm, approximately 2.54μm, approximately 2.55μm, approximately 2.56μm, approximately 2.57μm, approximately 2.58μm, approximately 2.59μm, approximately 2.6μm, approximately 2.61μm, approximately 2.62μm, approximately 2.63μm, approximately 2.64μm, approximately 2.65μm, approximately 2.66μm, approximately 2.67μm Approximately 2.68 μm, approximately 2.69 μm, approximately 2.7 μm, approximately 2.71 μm, approximately 2.72 μm, approximately 2.73 μm, approximately 2.74 μm, approximately 2.75 μm, approximately 2.76 μm, approximately 2.77 μm, approximately 2.78 μm, approximately 2.79 μm, approximately 2.8 μm, approximately 2.81 μm, approximately 2.82 μm, approximately 2.83 μm m, approximately 2.84 μm, approximately 2.85 μm, approximately 2.86 μm, approximately 2.87 μm, approximately 2.88 μm, approximately 2.89 μm, approximately 2.9 μm, approximately 2.91 μm, approximately 2.92 μm, approximately 2.93 μm, approximately 2.94 μm, approximately 2.95 μm, approximately 2.96 μm, approximately 2.97 μm, approximately 2.98 μm, approximately 2. 99μm, approximately 3μm, approximately 3.01μm, approximately 3.02μm, approximately 3.03μm, approximately 3.04μm, approximately 3.05μm, approximately 3.06μm, approximately 3.07μm, approximately 3.08μm, approximately 3.09μm, approximately 3.1μm, approximately 3.11μm, approximately 3.12μm, approximately 3.13μm, approximately 3.14μm, approximately 3.1 5μm, approximately 3.16μm, approximately 3.17μm, approximately 3.18μm, approximately 3.19μm, approximately 3.2μm, approximately 3.21μm, approximately 3.22μm, approximately 3.23μm, approximately 3.24μm, approximately 3.25μm, approximately 3.26μm, approximately 3.27μm, approximately 3.28μm, approximately 3.29μm, approximately 3.3μm, approximately 3 0.31μm, approximately 3.32μm, approximately 3.33μm, approximately 3.34μm, approximately 3.35μm, approximately 3.36μm, approximately 3.37μm, approximately 3.38μm, approximately 3.39μm, approximately 3.4μm, approximately 3.41μm, approximately 3.42μm, approximately 3.43μm, approximately 3.44μm, approximately 3.45μm, approximately 3.46μm Approximately 3.47 μm, approximately 3.48 μm, approximately 3.49 μm, approximately 3.5 μm, approximately 3.51 μm, approximately 3.52 μm, approximately 3.53 μm, approximately 3.54 μm, approximately 3.55 μm, approximately 3.56 μm, approximately 3.57 μm, approximately 3.58 μm, approximately 3.59 μm, approximately 3.6 μm, approximately 3.61 μm, approximately 3.62 μm μm, approximately 3.63μm, approximately 3.64μm, approximately 3.65μm, approximately 3.66μm, approximately 3.67μm, approximately 3.68μm, approximately 3.69μm, approximately 3.7μm, approximately 3.71μm, approximately 3.72μm, approximately 3.73μm, approximately 3.74μm, approximately 3.75μm, approximately 3.76μm, approximately 3.77μm, approximately 3.78μm, approx. 3.79μm, approx. 3.8μm, approx. 3.81μm, approx. 3.82μm, approx. 3.83μm, approx. 3.84μm, approx. 3.85μm, approx. 3 .86μm, approx. 3.87μm, approx. 3.88μm, approx. 3.89μm, approx. 3.9μm, approx. 3.91μm, approx. 3.92μm, approx. 3.93μm, approx. 3.94μm, approximately 3.95μm, approximately 3.96μm, approximately 3.97μm, approximately 3.98μm, approximately 3.99μm, approximately 4μm, approximately 4.01μm, approximately 4.02μm, approximately 4.03μm, approximately 4.04μm, approximately 4.05μm, approximately 4.06μm, approximately 4.07μm, approximately 4.08μm, approximately 4.09μm, approximately 4.1μm, about 4.11μm, about 4.12μm, about 4.13μm, about 4.14μm, about 4.15μm, about 4.16μm, about 4.17μm, Approx. 4.18μm, approx. 4.19μm, approx. 4.2μm, approx. 4.21μm, approx. 4.22μm, approx. 4.23μm, approx. 4.24μm, approx. 4.25μm , about 4.26μm, about 4.27μm, about 4.28μm, about 4.29μm, about 4.3μm, about 4.31μm, about 4.32μm, about 4.33μ m, approx. 4.34μm, approx. 4.35μm, approx. 4.36μm, approx. 4.37μm, approx. 4.38μm, approx. 4.39μm, approx. 4.4μm, approx. 4.41μ m, approx. 4.42 μm, approx. 4.43 μm, approx. 4.44 μm, approx. 4.45 μm, approx. 4.46 μm, approx. 4.47 μm, approx. 4.48 μm, approx. 4.4 9μm, about 4.5μm, about 4.51μm, about 4.52μm, about 4.53μm, about 4.54μm, about 4.55μm, about 4.56μm, about 4. 57μm, approx. 4.58μm, approx. 4.59μm, approx. 4.6μm, approx. 4.61μm, approx. 4.62μm, approx. 4.63μm, approx. 4.64μm, approx. 4 .65μm, approx. 4.66μm, approx. 4.67μm, approx. 4.68μm, approx. 4.69μm, approx. 4.7μm, approx. 4.71μm, approx. 4.72μm, approx. 4 This refers to a portion of a metal article that extends to a depth of approximately 0.73 μm, 4.74 μm, 4.75 μm, 4.76 μm, 4.77 μm, 4.78 μm, 4.79 μm, 4.8 μm, 4.81 μm, 4.82 μm, 4.83 μm, 4.84 μm, 4.85 μm, 4.86 μm, 4.87 μm, 4.88 μm, 4.89 μm, 4.9 μm, 4.91 μm, 4.92 μm, 4.93 μm, 4.94 μm, 4.95 μm, 4.96 μm, 4.97 μm, 4.98 μm, 4.99 μm, or approximately 5 μm, or somewhere in between.

[0029] In some examples, the surface extends from the outer surface of the metal article to a depth of approximately 2.0 μm inside the metal article (for example, to a depth of approximately 0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1 μm, 1.1 μm, 1.2 μm, 1.3 μm, 1.4 μm, 1.5 μm, 1.6 μm, 1.7 μm, 1.8 μm, 1.9 μm, or 2.0 μm). In some embodiments, the surface can extend from any outer surface of the metal article. For example, the surface can extend from a first side of the metal article (e.g., the top surface of the metal sheet), a second side of the metal article (e.g., the bottom surface of the metal sheet), a third side of the metal article (e.g., the first edge of the metal sheet), or a fourth side of the metal article (e.g., the second edge of the metal sheet).

[0030] As used herein, the term “subsurface” refers to the portion of a metal article that extends from the surface into the interior of the metal article to a maximum depth of approximately 30 μm (for example, approximately 5 μm to 30 μm, approximately 5 μm to 25 μm, approximately 6 μm to 25 μm, approximately 7 μm to 20 μm, approximately 8 μm to 15 μm, approximately 5 μm to 20 μm, approximately 10 μm to 30 μm, approximately 5 μm to 15 μm, or approximately 5 μm to 10 μm). Optionally, "subsurface" refers to the portion of the metal article that extends from the surface (for example, from a depth of approximately 5 μm) into the interior of the metal article to a depth of approximately 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, 20 μm, 21 μm, 22 μm, 23 μm, 24 μm, 25 μm, 26 μm, 27 μm, 28 μm, 29 μm, or 30 μm.

[0031] As used herein, the term “bulk” refers to the interior of a metal article extending from below a first surface to at least below a second surface, or from a depth of about 30 μm from the first surface to at least 30 μm from the second surface (for example, from a depth of about 30 μm from the top of a plate, shade, or sheet to a depth of about 30 μm from the bottom of a plate, shade, or sheet). Optionally, the term “bulk” refers to any volume of a metal article not otherwise described as “surface” or “subsurface.”

[0032] Among other properties, the metallic articles described herein contain coatings corresponding to the main alloying elements in the metal. Some non-limiting examples provided herein include (i) aluminum alloys containing Si as the main alloying element (i.e., 4xxx series aluminum alloys), (ii) aluminum alloys having Si as one of several main alloying elements (e.g., 6xxx series aluminum alloys having Si and magnesium (Mg) as the main alloying elements), (iii) aluminum alloys containing excess Si, (iv) metals having a surface enriched with Si-containing compounds (e.g., steel alloys coated with an aluminum-silicon (Al-Si) layer), and / or (v) aluminum alloys having an amount of Si greater than the impurity level (e.g., certain 5xxx series aluminum alloys).

[0033] In certain embodiments, the Si and optionally Mg content and ratios (e.g., in 6xxx series aluminum alloys) are controlled to enhance strength and formability. In some cases, the metallic articles described herein contain excess Si. Optionally, the Si and Mg content is controlled so that excess Si is present in the metallic articles described herein. The excess Si content can be calculated according to the method described in U.S. Patent No. 4,614,552, column 4, lines 49-52 (incorporated herein by reference). Briefly, Mg and Si combine as Mg2Si, resulting in a significant strength improvement after age hardening. In addition, Si-containing components such as Al(FeMn)Si can be formed. Excess Si is present when the Si content exceeds the stoichiometric ratio of Mg2Si and exceeds the amount contained in the Al(FeMn)Si component. The excess Si content can be calculated by subtracting the Si required for Mg2Si (Mg / 1.73) and the Fe-containing phase (Fe / 3) from the total Si content. The excess Si content can be approximately 1.4% to 25% by weight (for example, approximately 1.5% to 20% by weight, approximately 1.7% to 15% by weight, approximately 1.9% to 10% by weight, or approximately 2% to 5% by weight). For example, the excess Si content is approximately 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2%, 2.1%, 2.2%, 2.3%, 2.4%, 2.5%, 2.6%, 2.7%, 2.8%, 2.9%, 3%, 3.1%, 3.2%, 3.3%, 3.4%, 3.5%, 3.6%, 3.7%, 3.8%, 3.9%, 4%, 4.1%, 4.2%, 4.3%, 4.4%, 4.5%, 4.6%, 4.7%, 4.8%, 4.9%, 5% %, approximately 5.1%, approximately 5.2%, approximately 5.3%, approximately 5.4%, approximately 5.5%, approximately 5.6%, approximately 5.7%, approximately 5.8%, approximately 5.9%, approximately 6%, approximately 6.1%, approximately 6.2%, approximately 6.3%, approximately 6.4%, approximately 6.5%, approximately 6.6%, approximately 6.7%, approximately 6.8%, approximately 6.9%, approximately 7%, approximately 7.1%, approximately 7.2%, approximately 7.3%, approximately 7.4%, approximately 7.5%, approximately 7.6%, approximately 7.7%, approximately 7.8%, approximately 7.9%, approximately 8%, approximately 8.1%, approximately 8.2%, approximately 8.3%, approximately 8.4%, approximately 8.5%, approximately 8.6%, approximately 8.7%, approximately 8.8%, approximately 8.9%, approximately 9%, approximately 9.1%, approximately 9.2%, approximately 9.3%, approximately 9.4%, approximately 9.5%, approximately 9.6%, approximately 9.7%, approximately 9.8%, approximately 9.9%, approximately 10%, approximately 10.1%, approximately 10.2%, approximately 10.3%, approximately 10.4%, approximately 10.5%, approximately 10.6%, approximately 10.7%, approximately 10.8%, approximately 1 0.9%, approximately 11%, approximately 11.1%, approximately 11.2%, approximately 11.3%, approximately 11.4%, approximately 11.5%, approximately 11.6%, approximately 11.7%, approximately 11.8%, approximately 11.9%, approximately 12%, approximately 12.1%, approximately 12.2%, approximately 12.3%, approximately 12.4%, approximately 12.5%, approximately 12.6%, approximately 12.7% %, approximately 12.8%, approximately 12.9%, approximately 13%, approximately 13.1%, approximately 13.2%, approximately 13.3%, approximately 13.4%, approximately 13.5%, approximately 13.6%, approximately 13.7%, approximately 13.8%, approximately 13.9%, approximately 14%, approximately 14.1%, approximately 14.2%, approximately 14.3%, approximately 14.4%, approximately 14.5%, Approximately 14.6%, approximately 14.7%, approximately 14.8%, approximately 14.9%, approximately 15%, approximately 15.1%, approximately 15.2%, approximately 15.3%, approximately 15.4%, approximately 15.5%, approximately 15.6%, approximately 15.7%, approximately 15.8%, approximately 15.9%, approximately 16%, approximately 16.1%, approximately 16.2%, approximately 16.3%, approximately 16 0.4%, approximately 16.5%, approximately 16.6%, approximately 16.7%, approximately 16.8%, approximately 16.9%, approximately 17%, approximately 17.1%, approximately 17.2%, approximately 17.3%, approximately 17.4%, approximately 17.5%, approximately 17.6%, approximately 17.7%, approximately 17.8%, approximately 17.9%, approximately 18%, approximately 18.1%, approximately 18.2% %, approximately 18.3%, approximately 18.4%, approximately 18.5%, approximately 18.6%, approximately 18.7%, approximately 18.8%, approximately 18.9%, approximately 19%, approximately 19.1%, approximately 19.2%, approximately 19.3%, approximately 19.4%, approximately 19.5%, approximately 19.6%, approximately 19.7%, approximately 19.8%, approximately 19.9%, approximately 20%, approximately 20.1%, approximately 20.2%, approximately 20.3%, approximately 20.4%, approximately 20.5%, approximately 20.6%, approximately 20.7%, approximately 20.8%, approximately 20.9%, approximately 21%, approximately 21.1%, approximately 21.2%, approximately 21.3%, approximately 21.4%, approximately 21.5%, approximately 21.6%, approximately 21.7%, approximately 21.8%, approximately 21.9%, approximately 22%, approximately 22.1%, approximately 22.2%, approximately 22.3%, approximately 22.4%, approximately 22.5%, approximately 22.6%, approximately 22.7%, approximately 22.8%, approximately 22.9%, approximately 23%, approximately 23.1%, approximately 23.2%, approximately 23.3%, approximately 23.4%, approximately 23.5%, approximately 23.6%, approximately 23.It could be 7%, approximately 23.8%, approximately 23.9%, approximately 24%, approximately 24.1%, approximately 24.2%, approximately 24.3%, approximately 24.4%, approximately 24.5%, approximately 24.6%, approximately 24.7%, approximately 24.8%, approximately 24.9%, or approximately 25%.

[0034] In some examples, the alloying elements described herein can be diffused throughout the entire metallic article such that the concentration of the alloying element is distributed throughout the entire thickness (e.g., the bulk of the metal) of the metallic article (i.e., at least on the first surface, subsurface, and within the bulk portion). For example, a metallic article may contain a concentration of Si that is distributed throughout the metallic article and can be moved to at least the first surface during various processing steps, including homogenization, hot rolling, cold rolling, warm rolling, solution treatment, annealing, or any combination thereof. In some further examples, after moving to at least the first surface portion, the concentration of Si can be frozen within at least the first surface portion by employing any quenching technique known to those skilled in the art. Such metallic articles exhibit exceptional and unexpected bonding durability properties.

[0035] In some embodiments, the metallic articles are aluminum, aluminum alloys, magnesium, magnesium-based materials, titanium, titanium-based materials, copper, copper-based materials, steel, steel-based materials, bronze, bronze-based materials, brass, brass-based materials, composites, sheets used in composites, or any other suitable combination of metals or materials. The metallic articles may include monolithic materials as well as non-monolithic materials, such as roll-bonded materials, clad materials, composites (e.g., but not limited to carbon fiber-containing materials), or a variety of other materials. In some examples, the metallic articles are metal coils, metal strips, metal plates, metal sheets, metal billets, metal ingots, etc. In some cases, the systems and methods described herein can be used with non-metallic articles.

[0036] In some non-limiting examples, a metallic article may be an aluminum alloy article. An aluminum alloy article may have any preferred composition. In some non-limiting examples, an aluminum alloy article may contain Si as the main alloying element (e.g., 4xxx aluminum alloy), or an aluminum alloy article may contain Si as one of several main alloying elements (e.g., 6xxx aluminum alloy). Optionally, an aluminum alloy article may contain Si in amounts greater than the impurity level (e.g., 5xxx aluminum alloy). 4xxx aluminum alloys, 5xxx aluminum alloys, or 6xxx aluminum alloys may be modified to contain the Si content described herein (e.g., excess Si).

[0037] Non-limiting exemplary 4xxx series aluminum alloys for use in aluminum alloy articles include AA4004, AA4104, AA4006, AA4007, AA4008, AA4009, AA4010, AA4013, AA4014, AA4015, AA4015A, AA4115, AA4016, AA4017, AA4018, AA4019, AA4020, AA4021, AA4026, AA4032, AA4043, AA4043A, AA4143, AA4343, AA4643, AA4943, AA4044, AA4045, AA4145, AA4145A, AA4046, AA4047, AA4047A, or AA4147.

[0038] Examples of non-limiting 5xxx series aluminum alloys for use as aluminum alloy articles include AA5182, AA5183, AA5005, AA5005A, AA5205, AA5305, AA5505, AA5605, AA5006, AA5106, AA5010, AA5110, AA5110A, AA5210, AA5310, AA5016, AA5017, AA5018, AA5018A, AA5019, AA5019A, AA 5119, AA5119A, AA5021, AA5022, AA5023, AA5024, AA5026, AA5027, AA5028, AA5040, AA5140, AA5041, AA5042, AA5043, AA 5049, AA5149, AA5249, AA5349, AA5449, AA5449A, AA5050, AA5050A, AA5050C, AA5150, AA5051, AA5051A, AA5151, AA5251, AA5251A, AA5351, AA5451, AA5052, AA5252, AA5352, AA5154, AA5154A, AA5154B, AA5154C, AA5254, AA5354, AA5454, AA55 54, AA5654, AA5654A, AA5754, AA5854, AA5954, AA5056, AA5356, AA5356A, AA5456, AA5456A, AA5456B, AA5556, AA5556A, A Examples include A5556B, AA5556C, AA5257, AA5457, AA5557, AA5657, AA5058, AA5059, AA5070, AA5180, AA5180A, AA5082, AA5182, AA5083, AA5183, AA5183A, AA5283, AA5283A, AA5283B, AA5383, AA5483, AA5086, AA5186, AA5087, AA5187, or AA5088.

[0039] Non-limiting, exemplary 6xxx series aluminum alloys for use as aluminum alloy articles include AA6101, AA6101A, AA6101B, AA6201, AA6201A, AA6401, AA6501, AA6002, AA6003, AA6103, AA6005, AA6005A, AA6005B, AA6005C, AA6105, AA6205, AA6305, AA6006, AA6106, AA6206, AA 6306, AA6008, AA6009, AA6010, AA6110, AA6110A, AA6011, AA6111, AA6012, AA6012A, AA6013, AA6113, AA6014, AA6015 , AA6016, AA6016A, AA6116, AA6018, AA6019, AA6020, AA6021, AA6022, AA6023, AA6024, AA6025, AA6026, AA6027, AA60 28, AA6031, AA6032, AA6033, AA6040, AA6041, AA6042, AA6043, AA6151, AA6351, AA6351A, AA6451, AA6951, AA6053, AA 6055, AA6056, AA6156, AA6060, AA6160, AA6260, AA6360, AA6460, AA6460B, AA6560, AA6660, AA6061, AA6061A, AA6261 Examples include AA6361, AA6162, AA6262, AA6262A, AA6063, AA6063A, AA6463, AA6463A, AA6763, A6963, AA6064, AA6064A, AA6065, AA6066, AA6068, AA6069, AA6070, AA6081, AA6181, AA6181A, AA6082, AA6082A, AA6182, AA6091, or AA6092.

[0040] In some cases, the metallic article may be a steel alloy article. In some non-limiting examples, the steel alloy article may include an Al-Si layer incorporated into at least a first surface portion of the steel alloy article, thus providing Si enrichment on at least a first surface portion of the steel alloy article.

[0041] Pretreatment composition: This specification describes a pretreatment composition that imparts increased bonding durability to a metal article. The pretreatment composition comprises at least one Si-containing compound and optionally one or more additional components. A suitable Si-containing compound for use in the pretreatment composition is (e.g., SiO₂). xSi-containing compounds (containing a portion of the Si compound) may include, for example, (3-aminopropyl)triethoxysilane (APS), 1,2-bis(triethoxysilyl)ethane (BTSE), glycidyl-oxypropyl-trimethoxysilane (GPS), tetraethoxysilane (TEOS), vinyltriethoxysilane (VTES), bis[3-(trimethoxysilyl)propyl]amine, vinyltrimethoxysilane, methyltriethoxysilane (MTES), and combinations thereof. The Si-containing compounds may optionally be present in aqueous media, organic solvents, or combinations thereof. Aqueous media may include, for example, tap water, purified water, distilled water, demineralized water, and / or deionized water. Suitable organic solvents include, for example, polar organic solvents. In some examples, organic solvents such as acetone, ethanol, methanol, isopropanol, and / or ethyl acetate may be present. Optionally, solutions containing at least one Si-containing compound may include combinations of aqueous media and organic solvents. In some examples, one or more aqueous media may be present in the solution in an amount of at least about 5 vol%, at least about 10 vol%, at least about 15 vol%, at least about 20 vol%, at least about 25 vol%, at least about 30 vol%, at least about 35 vol%, at least about 40 vol%, at least about 45 vol%, at least about 50 vol%, at least about 55 vol%, at least about 60 vol%, at least about 65 vol%, at least about 70 vol%, at least about 75 vol%, at least about 80 vol%, at least about 85 vol%, at least about 90 vol%, or at least about 95 vol%. In some examples, an organic solvent(s) may be present in the solution in an amount of at least about 5 vol%, at least about 10 vol%, at least about 15 vol%, at least about 20 vol%, at least about 25 vol%, at least about 30 vol%, at least about 35 vol%, at least about 40 vol%, at least about 45 vol%, at least about 50 vol%, at least about 55 vol%, at least about 60 vol%, at least about 65 vol%, at least about 70 vol%, at least about 75 vol%, at least about 80 vol%, at least about 85 vol%, at least about 90 vol%, or at least about 95 vol%.

[0042] Optionally, the solution containing the Si compound includes an aqueous medium which may contain, for example, acetone, ethanol, methanol, isopropanol and / or ethyl acetate in an amount of up to about 90 vol% (e.g., up to about 85 vol%, up to about 80 vol%, up to about 75 vol%, up to about 70 vol%, up to about 65 vol%, up to about 60 vol%, up to about 55 vol%, up to about 50 vol%, up to about 45 vol%, up to about 40 vol%, up to about 35 vol%, up to about 30 vol%, up to about 25 vol%, up to about 20 vol%, up to about 15 vol%, or up to about 10 vol%).

[0043] Method for preparing metal articles As described below, certain processing steps and tempering, including rolling and tempering, heat treatment and tempering, and / or surface preparation steps and tempering (to give a few examples, etching and / or cleaning), provide the above-mentioned metallic articles having desirable bonding durability properties. In some non-limiting examples, the metallic articles described herein may be aluminum alloy articles. Methods for providing aluminum alloy articles described herein include providing an aluminum alloy having Si as the main alloying element (e.g., 4xxx series aluminum alloy, 5xxx series aluminum alloy, or 6xxx series aluminum alloy), providing a Si-containing pretreatment for forming a Si-containing coating on an aluminum alloy article, and Si-containing compounds present in the aluminum alloy article (e.g., excess Si) and SiO present in the coating. x The process may include the step of treating a coated aluminum alloy article to stimulate Si-O-Si bonding interactions between the parts. In some cases, providing an aluminum alloy having Si as the main alloying element can be done according to methods commonly known in the art, such as those briefly described below.

[0044] In some non-limiting examples, controlling the diffusion rate of a mobile element can provide selective diffusion of that element. For example, heat can be extracted from a molten metal at a rate that promotes the diffusion of a first mobile element while simultaneously suppressing the diffusion of a second mobile element. Thus, the surface of a metallic article can be selectively enriched with a selected mobile element (e.g., Si) during the solidification of the molten alloy to provide a metallic article.

[0045] Any suitable metal described herein (i.e., containing Si, such as excess Si) can be cast by any suitable method to produce a cast article. In some examples, the metal can be cast using a direct chill (DC) casting process to form an ingot. In some examples, the metal can be cast using a continuous casting (CC) process, which may include but is not limited to the use of a twin-belt caster, twin-roll caster, or block caster, to form a cast article in the form of a billet, slap, shade, strip, etc. The cast article can then be subjected to processing steps, which may include but are not limited to homogenization, hot rolling, cold rolling, solution heat treatment, quenching, and / or aging, based on the specific metal used to prepare the article (e.g., a specific aluminum alloy system). Following processing, the metal article can undergo surface preparation steps, as further described below.

[0046] surface preparation Optionally, aluminum alloy articles cast by DC casting or CC casting as described herein and subsequently processed may be subjected to the surface preparation processes described below. Although this description is provided in the context of aluminum alloys, the aluminum alloy articles and methods described herein can be used for any suitable metal articles, and any suitable metal articles having any suitable gauge, including foils, sheets, plates, slabs, billets, ingots, etc., and metal articles of any shape.

[0047] cleaning The pretreatment process described herein includes the step of applying a cleaner (also referred to herein as an entry cleaner) to one or more surfaces of an aluminum alloy article. The entry cleaner removes residual oil or loosely adhering oxides from the coil surface. Optionally, the entry cleaning may be carried out using a solvent (e.g., an aqueous solvent or an organic solvent). Optionally, one or more additives may be added to the solvent.

[0048] Pre-etching The methods described herein also include the step of pre-etching one or more surfaces of an aluminum alloy article. The surfaces of an aluminum alloy article can be pre-etched using acid etching (i.e., an etching procedure comprising an acidic solution). Acid etching prepares the surface for subsequent pretreatment. Exemplary acids for performing acid etching include sulfuric acid, hydrofluoric acid, nitric acid, phosphoric acid, and combinations thereof. In some non-limiting examples, pre-etching can be performed at a maximum of approximately 3 g / m². 2 The surface material is removed, exposing the silicon present in the aluminum alloy article on or near the surface of the aluminum alloy article. In some cases, the exposed silicon may be elemental silicon, silicon in silicon-containing compounds (e.g., Mg2Si), etc.

[0049] Pre-treatment After the pre-etching step, the surface of the metal article can be rinsed with water or a solvent. Then, a pretreatment (e.g., the Si-containing pretreatment described above) can be applied to the surface of the metal article. Optionally, the pretreatment may include adhesion promoters, corrosion inhibitors, coupling agents, antimicrobial agents, or mixtures thereof. In some non-limiting examples, excess Si in the aluminum alloy article may be replaced by oxygen atoms (e.g., SiO2) present in the pretreatment. x It interacts with (partially) and can enhance pretreatment adhesion via Si-O-Si bond interactions. In some examples, excess Si in the surface of the metal article interacts with O atoms (e.g., Al2O3) in the surface of the metal article and / or Si and / or O atoms (e.g., SiO2O3) in the pretreatment layer.x In other embodiments, excess Si in the surface of the metal article interacts with O atoms in the surface of the metal article (e.g., metal oxides (e.g., Al2O3), O atoms in the metal lattice, oxidized excess Si, O present in Si-containing compounds in alloys, other O-containing compounds in alloys, etc.) and Si atoms in the pre-treatment layer (e.g., Si atoms or SiO x It can interact with (partially) and enhance pretreatment adhesion via Si-O-Si interactions.

[0050] In some cases, silicon-containing compounds in Si-based pretreatment are SiO x It can include a portion where x is an integer in the range of 1 to 4 (e.g., 1, 2, 3, or 4). For example, pretreatment of siloxanes, polysiloxanes, silanols, tetraethyl orthosilicates, tetraalkyl silicates, hexamethyldisiloxane (HMDSO), tetraethoxysilane (TEOS), triethoxysilane, etc. is SiO x It may contain a portion of these. Therefore, siloxanes, polysiloxanes, silanols, tetraethyl orthosilicates, tetraalkyl silicates, hexamethyldisiloxane (HMDSO), tetraethoxysilane (TEOS), triethoxysilane, etc., can be used individually or in any combination thereof as a pretreatment.

[0051] In some cases, pretreatment can be applied by bar coating, roller coating, spray coating, dip coating, any suitable coating technique known in the art, or any combination thereof. After coating, the pretreatment can be cured to coat the aluminum alloy surface. In certain cases, curing can be carried out at temperatures of about 200°C to about 300°C (e.g., about 210°C to about 290°C, about 215°C to about 285°C, about 220°C to about 280°C, about 220°C to about 300°C, about 200°C to about 275°C, about 205°C to about 295°C, about 225°C to about 275°C, about 215°C to about 300°C, about 230°C to about 270°C, about 235°C to about 265°C, or about 240°C to about 260°C). For example, curing occurs at approximately 200°C, 201°C, 202°C, 203°C, 204°C, 205°C, 206°C, 207°C, 208°C, 209°C, 210°C, 211°C, 212°C, 213°C, 214°C, 215°C, 216°C, 217°C, 218°C, 219°C, 220°C, 221°C, 222°C, 223°C, and 224°C. Approximately 225°C, approximately 226°C, approximately 227°C, approximately 228°C, approximately 229°C, approximately 230°C, approximately 231°C, approximately 232°C, approximately 233°C, approximately 234°C, approximately 235°C, approximately 236°C, approximately 237°C, approximately 238°C, approximately 239°C, approximately 240°C, approximately 241°C, approximately 242°C, approximately 243°C, approximately 244°C, approximately 245°C, approximately 246°C, approximately 247°C, approximately 248°C, approximately 249°C, approximately 250°C, approximately 251℃, approximately 252℃, approximately 253℃, approximately 254℃, approximately 255℃, approximately 256℃, approximately 257℃, approximately 258℃, approximately 259℃, approximately 260℃, approximately 261℃, approximately 262℃, approximately 263℃, approximately 264℃, approximately 265℃, approximately 266℃, approximately 267℃, approximately 268℃, approximately 269℃, approximately 270℃, approximately 271℃, approximately 272℃, approximately 273℃, approximately 274℃, approximately 275℃, approximately 276℃, approximately 2 It can be carried out at temperatures of 77°C, approximately 278°C, approximately 279°C, approximately 280°C, approximately 281°C, approximately 282°C, approximately 283°C, approximately 284°C, approximately 285°C, approximately 286°C, approximately 287°C, approximately 288°C, approximately 289°C, approximately 290°C, approximately 291°C, approximately 292°C, approximately 293°C, approximately 294°C, approximately 295°C, approximately 296°C, approximately 297°C, approximately 298°C, approximately 299°C, or approximately 300°C.

[0052] In certain cases, after applying pretreatment, curing can be performed over a period of approximately 5 to 15 seconds (for example, approximately 6 to 14 seconds, 6 to 12 seconds, 6 to 10 seconds, 5 to 10 seconds, 7 to 13 seconds, or 7 to 8 seconds). For example, curing can be performed over a period of approximately 5 seconds, 6 seconds, 7 seconds, 8 seconds, 9 seconds, 10 seconds, 11 seconds, 12 seconds, 13 seconds, 14 seconds, or 15 seconds.

[0053] In certain embodiments, the applied pretreatment is approximately 0.5 mg / m². 2 ~about 100mg / m 2 (For example, about 1 mg / m²) 2 ~about 100mg / m 2 , about 2mg / m 2 ~about 90mg / m 2 , about 3mg / m 2 ~about 80mg / m 2 , about 4mg / m 2 ~about 70mg / m 2 , about 5mg / m 2 ~about 60mg / m 2 , about 6mg / m 2 ~about 50mg / m 2 , about 7mg / m 2 ~about 40mg / m 2 , about 8mg / m 2 ~about 30mg / m 2 , or approximately 9 mg / m² 2 ~about 20mg / m 2 The coating weight can be approximately 0.5 mg / m². For example, the applied pretreatment may have a coating weight of approximately 0.5 mg / m². 2 , about 0.6mg / m 2 , about 0.7mg / m 2 , about 0.8mg / m 2 , about 0.9mg / m 2 , about 1mg / m 2 , about 1.1mg / m 2 , about 1.2mg / m 2 , about 1.3mg / m 2 , about 1.4mg / m 2 , about 1.5mg / m 2 , about 1.6mg / m 2 , about 1.7mg / m 2 , about 1.8mg / m2 Approximately 1.9 mg / m³ 2 Approximately 2mg / m 2 Approximately 2.1 mg / m³ 2 Approximately 2.2 mg / m 2 Approximately 2.3 mg / m³ 2 Approximately 2.4 mg / m 2 Approximately 2.5 mg / m 2 Approximately 2.6 mg / m 2 Approximately 2.7 mg / m³ 2 Approximately 2.8 mg / m³ 2 Approximately 2.9 mg / m³ 2 Approximately 3mg / m 2 Approximately 3.1 mg / m³ 2 Approximately 3.2 mg / m 2 Approximately 3.3 mg / m³ 2 Approximately 3.4 mg / m 2 Approximately 3.5 mg / m 2 Approximately 3.6 mg / m³ 2 Approximately 3.7 mg / m³ 2 Approximately 3.8 mg / m³ 2 Approximately 3.9 mg / m³ 2 Approximately 4 mg / m 2 Approximately 4.1 mg / m³ 2 Approximately 4.2 mg / m 2 Approximately 4.3 mg / m 2 Approximately 4.4 mg / m 2 Approximately 4.5 mg / m 2 Approximately 4.6 mg / m³ 2 Approximately 4.7 mg / m³ 2 Approximately 4.8 mg / m³ 2 Approximately 4.9 mg / m³ 2 Approximately 5mg / m 2 Approximately 5.1 mg / m³ 2 Approximately 5.2 mg / m 2 Approximately 5.3 mg / m 2 Approximately 5.4 mg / m 2 Approximately 5.5 mg / m 2 Approximately 5.6 mg / m³ 2 Approximately 5.7 mg / m³ 2 Approximately 5.8 mg / m³ 2 Approximately 5.9 mg / m³ 2 Approximately 6 mg / m 2 Approximately 6.1 mg / m³ 2 Approximately 6.2 mg / m³ 2 Approximately 6.3 mg / m³ 2 Approximately 6.4 mg / m³2 Approximately 6.5 mg / m 2 Approximately 6.6 mg / m³ 2 Approximately 6.7 mg / m³ 2 Approximately 6.8 mg / m³ 2 Approximately 6.9 mg / m³ 2 Approximately 7mg / m 2 Approximately 7.1 mg / m³ 2 Approximately 7.2 mg / m 2 Approximately 7.3 mg / m 2 Approximately 7.4 mg / m³ 2 Approximately 7.5 mg / m 2 Approximately 7.6 mg / m³ 2 Approximately 7.7 mg / m³ 2 Approximately 7.8 mg / m³ 2 Approximately 7.9 mg / m³ 2 Approximately 8mg / m 2 Approximately 8.1 mg / m³ 2 Approximately 8.2 mg / m³ 2 Approximately 8.3 mg / m³ 2 Approximately 8.4 mg / m³ 2 Approximately 8.5 mg / m 2 Approximately 8.6 mg / m³ 2 Approximately 8.7 mg / m³ 2 Approximately 8.8 mg / m³ 2 Approximately 8.9 mg / m³ 2 Approximately 9mg / m 2 Approximately 9.1 mg / m³ 2 Approximately 9.2 mg / m³ 2 Approximately 9.3 mg / m³ 2 Approximately 9.4 mg / m³ 2 Approximately 9.5 mg / m 2 Approximately 9.6 mg / m³ 2 Approximately 9.7 mg / m³ 2 Approximately 9.8 mg / m³ 2 Approximately 9.9 mg / m³ 2 Approximately 10 mg / m 2 Approximately 11 mg / m 2 Approximately 12 mg / m 2 Approximately 13 mg / m 2 Approximately 14 mg / m 2 Approximately 15 mg / m 2 Approximately 16 mg / m 2 Approximately 17 mg / m 2 Approximately 18 mg / m 2 Approximately 19 mg / m 2 Approximately 20 mg / m2 Approximately 21 mg / m 2 Approximately 22 mg / m 2 Approximately 23 mg / m 2 Approximately 24 mg / m 2 Approximately 25 mg / m 2 Approximately 26 mg / m 2 Approximately 27 mg / m 2 Approximately 28 mg / m 2 Approximately 29 mg / m 2 Approximately 30 mg / m 2 Approximately 31 mg / m 2 Approximately 32 mg / m 2 Approximately 33 mg / m 2 Approximately 34 mg / m 2 Approximately 35 mg / m 2 Approximately 36 mg / m 2 Approximately 37 mg / m 2 Approximately 38 mg / m 2 Approximately 39 mg / m 2 Approximately 40 mg / m 2 Approximately 41 mg / m 2 Approximately 42 mg / m 2 Approximately 43 mg / m 2 Approximately 44 mg / m 2 Approximately 45 mg / m 2 Approximately 46 mg / m 2 Approximately 47 mg / m 2 Approximately 48 mg / m 2 Approximately 49 mg / m 2 Approximately 50 mg / m 2 Approximately 51 mg / m 2 Approximately 52 mg / m 2 Approximately 53 mg / m 2 Approximately 54 mg / m 2 Approximately 55mg / m 2 Approximately 56 mg / m 2 Approximately 57 mg / m 2 Approximately 58 mg / m 2 Approximately 59 mg / m 2 Approximately 60 mg / m 2 Approximately 61 mg / m 2 Approximately 62 mg / m 2 Approximately 63 mg / m 2 Approximately 64 mg / m 2 Approximately 65mg / m 2 Approximately 66 mg / m 2 Approximately 67 mg / m 2, about 68mg / m 2 , about 69mg / m 2 , about 70mg / m 2 , about 71mg / m 2 , about 72mg / m 2 , about 73mg / m 2 , about 74mg / m 2 , about 75mg / m 2 , about 76mg / m 2 , about 77mg / m 2 , about 78mg / m 2 , about 79mg / m 2 , about 80mg / m 2 , about 81mg / m 2 , about 82mg / m 2 , about 83mg / m 2 , about 84mg / m 2 , about 85mg / m 2 , about 86mg / m 2 , about 87mg / m 2 , about 88mg / m 2 , about 89mg / m 2 , about 90mg / m 2 , about 91mg / m 2 , about 92mg / m 2 , about 93mg / m 2 , about 94mg / m 2 , about 95mg / m 2 , about 96mg / m 2 , about 97mg / m 2 , about 98mg / m 2 Approximately 99 mg / m² 2 , or approximately 100 mg / m² 2 It can have a coating weight of [weight].

[0054] In certain embodiments, the applied pretreatment may have a dry thickness of approximately 0.01 nm to approximately 20 nm (for example, approximately 1 nm to approximately 20 nm, approximately 1 nm to approximately 19 nm, approximately 2 nm to approximately 18 nm, approximately 3 nm to approximately 17 nm, approximately 5 nm to approximately 20 nm, approximately 4 nm to approximately 16 nm, approximately 5 nm to approximately 15 nm, approximately 6 nm to approximately 14 nm, approximately 7 nm to approximately 13 nm, approximately 8 nm to approximately 12 nm, approximately 9 nm to approximately 11 nm, approximately 2 nm to approximately 14 nm, approximately 3 nm to approximately 20 nm, approximately 1 nm to approximately 19 nm, or 4 nm to approximately 19 nm).

[0055] Methods for joining metal articles In some non-limiting examples, a method for joining a first metal to a second metal includes (i) providing a first metal having a first surface portion containing excess Si, (ii) applying a surface pretreatment layer comprising one or more Si-containing compounds to the first surface portion of the first metal to form a pretreated surface portion of the first metal, wherein either the first surface portion of the first metal or one or more Si-containing compounds contains O, and the application stimulates Si-O-Si bond interactions between the excess Si present in the first surface portion of the first metal and the one or more Si-containing compounds present in the surface pretreatment layer; and joining the pretreated surface portion of the first metal to the surface of the second metal.

[0056] In some non-limiting examples, a first metal (e.g., an aluminum alloy) and a second metal are joined to form a joint of any preferred configuration, including laps, edges, butts, T-butts, hems, T-edges, and the like. In some non-limiting examples, adhesives can be used to join the two metal products together.

[0057] In some non-limiting examples, the metal articles of this disclosure (e.g., bonded metal articles) have improved bond durability, demonstrated as sustained bond strength under harsh environmental conditions in a neutral salt spray test conducted in accordance with ASTM standard B117. As described herein, the Si-O-Si bond interactions of the pre-treated aluminum alloys described herein improve bond durability more than (a) aluminum alloys having excess Si content but not pre-treated with a Si-containing pretreatment, (b) aluminum alloys pre-treated with a Si-containing pretreatment but not having excess Si, and (c) aluminum alloys not having excess Si and not pre-treated with a Si-containing pretreatment. For example, an aluminum alloy having excess Si as described herein, pre-treated with a Si-containing pretreatment as described herein, and bonded to a second metal exhibits stronger bond durability than an aluminum alloy having excess Si, pre-treated with a non-Si-containing pretreatment (e.g., titanium-zirconium (TiZr) pretreatment), and bonded to a second metal. Furthermore, an aluminum alloy having excess Si as described herein, pretreated with the Si-containing pretreatment described herein, and bonded to a second metal exhibits stronger bond durability than an aluminum alloy without excess Si (e.g., excess Si=0), pretreated with the Si-containing pretreatment, and bonded to a second metal. Moreover, an aluminum alloy having excess Si as described herein, pretreated with the Si-containing pretreatment described herein, and bonded to a second metal exhibits stronger bond durability than an aluminum alloy without excess Si, pretreated with the non-Si-containing pretreatment (e.g., TiZr), and bonded to a second metal.

[0058] In some examples, the second metal has one or more surfaces containing excess Si (e.g., excess Si is present in an amount greater than about 1.4% by weight). In certain embodiments, the second metal is pretreated with a Si-containing pretreatment as described herein. In some cases, the excess Si in the second metal surface interacts with one or more Si-containing compounds during the pretreatment. Si-O-Si bond interactions increase bond durability when the metal article is bonded to the first metal.

[0059] In some cases, metal articles having excess Si as described herein and pretreated with the Si-containing pretreatment described herein show at least about 40% improvement in bond durability compared to metal parts without excess Si and / or metal articles that are not pretreated or are pretreated with a non-Si-containing pretreatment. For example, the improvement in bond durability of metal articles pretreated with the Si-containing pretreatment described herein may be about 45% or more, about 50% or more, about 55% or more, about 60% or more, about 65% or more, about 70% or more, or about 75% or more compared to metal parts without excess Si and / or metal articles that are not pretreated or are pretreated with a non-Si-containing pretreatment.

[0060] In certain embodiments, metal articles having excess Si as described herein and pretreated with the Si-containing pretreatment described herein exhibit a slight loss of bond strength when subjected to a neutral salt spray test. For example, after exposure to a neutral salt spray for up to 20 weeks, metal articles having excess Si pretreated with the Si-containing pretreatment exhibit a loss of bond strength of less than about 40%, less than about 35%, less than about 30%, less than about 25%, or less than 20%. In some comparative examples, metal articles having excess Si as described herein, pretreated with the TiZr pretreatment, and subjected to a bond durability test may exhibit a loss of bond strength of at least about 40% after exposure to a neutral salt spray for up to 20 weeks. For example, a metal article having excess Si and pre-treated with TiZr pretreatment may exhibit a bond strength loss of at least 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%, or about 75%.

[0061] How to use The aluminum alloy articles and methods described herein can be used in automotive, electronic equipment, and transportation applications, such as commercial vehicles, aircraft, or railway applications. For example, aluminum alloy articles can be used in chassis, cross members, and chassis components (including, but not limited to, all components between the two C channels of a commercial vehicle chassis) to obtain strength that serves as a complete or partial replacement for high-strength steel.

[0062] In certain embodiments, aluminum alloy articles and methods can be used to prepare motor vehicle body parts. For example, the aluminum alloy articles and methods of the Disclosure can be used to prepare and / or form automotive body parts, such as bumpers, side beams, roof beams, cross beams, pillar reinforcements (e.g., A-pillars, B-pillars, and C-pillars), inner panels, side panels, floor panels, tunnels, structural panels, reinforcement panels, inner hoods, or trunk lid panels. The aluminum alloy articles and methods of the Disclosure can also be used, for example, to prepare exterior and interior panels for aircraft or railway vehicle applications.

[0063] The aluminum alloy articles and methods described herein can also be used in electronic applications, for example, to prepare and / or form external and internal enclosures. For example, the aluminum alloy articles and methods described herein can also be used to prepare housings for electronic devices, including mobile phones and tablet computers. In some examples, aluminum alloy articles can be used to prepare housings for the outer casing of a mobile phone (e.g., a smartphone) and the bottom chassis of a tablet.

[0064] In certain embodiments, aluminum alloy articles and methods can be used to prepare and / or form aerospace vehicle body component articles. For example, the aluminum alloy articles and methods of this disclosure can be used to prepare aircraft body components, such as skin alloys.

[0065] Optionally, aluminum alloy articles and methods can be used, among other uses, to prepare and / or form beverage and food containers.

[0066] In some examples, the aluminum alloy can be manufactured into an aluminum alloy article including any coating as described herein. In some examples, the alloy can be manufactured into a molded article formed from any aluminum alloy article as described herein and including any coating layer formed from a pretreatment composition as described herein. In some examples, the alloy is a molded article formed from any aluminum alloy article as described herein and including a Si-containing coating as described herein, and the molded article is joined to another article formed from a similar alloy, a similar metal, a different alloy or a different metal (e.g., a second metal or a second alloy). In some non-limiting examples, the aluminum alloy and the second metal and / or alloy are joined to form a joint of any preferred configuration, including laps, edges, butts, T-butts, hems, T-edges, etc. In some non-limiting examples, adhesives can be used to join the two metal articles together. As used herein, bond durability refers to the bond strength after exposure to harsh conditions (e.g., a neutral salt spray test) and subsequent tensile tests (e.g., to evaluate the strength of the bond after exposure to harsh conditions).

[0067] Examples Example 1 is a pre-treated metal article comprising a first surface portion containing excess Si; and a surface pre-treatment layer containing one or more Si-containing compounds, wherein either the first surface portion of the first metal or one or more of the Si-containing compounds contains O, and a Si-O-Si bond interaction exists between the excess Si present in the first surface portion and the one or more Si-containing compounds present in the surface pre-treatment layer, and the surface pre-treatment layer is adhered to the first surface portion.

[0068] Example 2 is a pre-treated metal article according to any preceding or succeeding example, wherein the excess Si is present in the first surface portion in an amount exceeding approximately 1.4% by weight.

[0069] Example 3 is a pre-treated metal article as described in any of the preceding or succeeding examples, wherein the pre-treated metal article includes aluminum or an aluminum alloy, steel, magnesium or a magnesium alloy, titanium or a titanium alloy, copper or a copper alloy, any suitable metal or metal alloy, or any combination thereof.

[0070] Example 4 is a pre-treated metal article according to any preceding or succeeding example, wherein the pre-treated metal article is an aluminum alloy.

[0071] Example 5 is a pre-treated metal article as described in any preceding or succeeding example, wherein the aluminum alloy includes a 4xxx series aluminum alloy, a 5xxx series aluminum alloy, or a 6xxx series aluminum alloy.

[0072] Example 6 is a pre-treated metal article according to any preceding or succeeding example, wherein the pre-treated metal article is an automotive structural component, an aerospace structural component, a transport structural component, an automotive body component, an aerospace skin panel, a transport body component, an architectural component, an aesthetic component, an electronic device housing, or a beverage or food container.

[0073] Example 7 is a method for joining a first metal to a second metal, comprising: providing a first metal having a first surface portion containing excess Si; applying a surface pretreatment layer containing one or more Si-containing compounds to the first surface portion of the first metal to form a pretreated surface portion of the first metal, wherein either the first surface portion of the first metal or the one or more Si-containing compounds contains O, and the application stimulates Si-O-Si bond interactions between the excess Si present in the first surface portion of the first metal and the one or more Si-containing compounds present in the surface pretreatment layer; and joining the pretreated surface portion of the first metal to the surface of the second metal.

[0074] Example 8 is the method according to any preceding or subsequent example, wherein one or more of the following conditions are achieved: (a) the bond durability between the pre-treated surface portion of the first metal and the surface of the second metal is greater than the bond durability between the surface portion of the metal pre-treated with a surface pre-treatment that contains excess Si and does not contain one or more Si-containing compounds and (ii) the second metal; (b) the bond durability between the pre-treated surface portion of the first metal and the surface of the second metal is greater than the bond durability between the surface portion of the metal pre-treated with a surface pre-treatment that does not contain excess Si and contains one or more Si-containing compounds and (ii) the second metal; or (c) the bond durability between the pre-treated surface portion of the first metal and the surface of the second metal is greater than the bond durability between the surface portion of the metal pre-treated with a surface pre-treatment that does not contain excess Si and does not contain one or more Si-containing compounds and (ii) the second metal.

[0075] Example 9 is the method according to any preceding or succeeding example, wherein the first metal includes aluminum or an aluminum alloy, steel, magnesium or a magnesium alloy, titanium or a titanium alloy, copper or a copper alloy, any suitable metal or metal alloy, or any combination thereof.

[0076] Example 10 is the method according to any preceding or subsequent examples, wherein the first metal includes an aluminum alloy.

[0077] Example 11 is the method according to any prior or subsequent example, wherein the aluminum alloy includes a 4xxx series aluminum alloy, a 5xxx series aluminum alloy, or a 6xxx series aluminum alloy.

[0078] Example 12 is the method according to any preceding or succeeding example, wherein the second metal includes aluminum or an aluminum alloy, steel, magnesium or a magnesium alloy, titanium or a titanium alloy, copper or a copper alloy, any suitable metal or metal alloy, or any combination thereof.

[0079] Example 13 is the method according to any preceding or subsequent example, wherein the excess Si is present in an amount exceeding approximately 1.4% by weight of at least the first surface portion of the first metal.

[0080] Example 14 is a method of any prior or subsequent example, further comprising etching at least the first surface portion of the first metal before the application.

[0081] Example 15 is a method according to any prior or subsequent examples, wherein etching of at least the first surface portion of the first metal exposes Si in the first surface portion by removing up to about 3 grams / square meter of surface material.

[0082] Example 16 is the method of any preceding or subsequent example, further comprising cleaning at least the first surface portion of the first metal before the application.

[0083] Example 17 is a method of any preceding or subsequent example in which cleaning at least the first surface portion of the first metal removes natural oxide or hydroxide species from at least the first surface portion of the first metal.

[0084] Example 18 is a method according to any preceding or subsequent example, which includes bar coating, roll coating, spray coating, or dip coating, wherein the surface pretreatment layer is applied to at least the first surface portion of the first metal.

[0085] Example 19 is a method according to any preceding or subsequent example, further comprising curing the surface pretreatment layer.

[0086] Example 20 is a bonded metal structure prepared according to the method described in any of the preceding or succeeding examples.

[0087] Example 21 is a bonded metal structure described in any preceding or succeeding example, wherein the bonded metal structure experiences a bond strength loss of less than 40% after 20 weeks of exposure to a neutral salt spray test.

[0088] The following examples serve to further illustrate the present invention, but do not constitute any limitation thereof. On the contrary, it should be clearly understood that various embodiments, modifications, and equivalents can be relied upon, and these may be suggested to those skilled in the art without departing from the spirit of the invention after reading the description herein. In the tests described in the following examples, conventional procedures were followed unless otherwise stated. Some of the procedures are described below for illustrative purposes. [Examples]

[0089] Example 1: Bonding durability Aluminum alloys containing Si as the main alloying element, with high concentrations of Si on the aluminum alloy surface, were prepared for bonding durability testing. 6xxx series aluminum alloys were used for each bonding durability test sample. The aluminum alloys were cut into eight test coupons and coated with pretreatments. Four aluminum alloy coupons were coated with a Si-containing pretreatment (referred to as "Si-PT"), and four aluminum alloy samples were pretreated with a titanium-zirconium (referred to as "TiZr") pretreatment, a commonly known comparative treatment in the art. The similarly coated coupons were then bonded together with commercially available adhesives provided by Sika Corporation (Lyndhurst, NJ). Sika 497 and Sika 498 / 3 are impact-resistant structural adhesives. Sika 497 is a low-viscosity impact-resistant structural adhesive, and Sika 498 / 3 is a high-viscosity impact-resistant structural adhesive. Alloy reference sample A contained two test coupons coated with Si-PT and bonded with adhesive formulation Sika 498 / 3. Alloy reference sample B contained two test coupons coated with Si-PT and bonded with adhesive formulation Sika 497. Alloy reference sample C contained two test coupons coated with TiZr and bonded with adhesive formulation Sika 498 / 3. Alloy reference sample D contained two test coupons coated with TiZr and bonded with adhesive formulation BM4601 (provided by Dow Automotive Systems, Wilmington, DE). Alloy reference samples A, B, C, and D were repeated to provide four test samples for each alloy reference sample, and each alloy reference sample was evaluated after different time intervals during testing. The results of the adhesive durability tests are provided in Table 1 below. [Table 1]

[0090] Bond durability testing was performed by employing a neutral salt spray test on alloy reference samples A, B, C, and D. The bond strength of each alloy reference sample was tested after no exposure (e.g., 0 weeks), after 2 weeks of exposure to the neutral salt spray test, after 6 weeks of exposure to the neutral salt spray test, after 12 weeks of exposure to the neutral salt spray test, and after 20 weeks of exposure to the neutral salt spray test. Bond durability was demonstrated as the loss of bond strength for each sample (i.e., alloy reference samples A, B, C, and D, tested without exposure to the neutral salt spray test, served as benchmarks for 0% strength loss). The results are summarized in Table 2 below: [Table 2]

[0091] Figure 1 is a graph showing the strength loss of the bonded aluminum alloy samples described above. A strength loss of 40% (indicated by dashed lines crossing each set of histograms) was deemed unacceptable. As is clear from the graph and Table 2 above, alloy references A and B, which employ a Si-containing pretreatment coating applied to aluminum alloys with high concentrations of Si on the aluminum alloy surface, showed high bond strength and minimal bond strength loss after 2 weeks, 6 weeks, 12 weeks, and 20 weeks of exposure in neutral salt spray testing, demonstrating increased bond durability compared to current pretreatment techniques (for example, samples pretreated with TiZr showed bond strength loss of over 40% after 6 weeks, 12 weeks, and 20 weeks of neutral salt spray exposure).

[0092] Figures 2-5 are digital optical images of test samples after exposure to the neutral salt spray test. Samples that withstood the neutral salt spray test (e.g., samples that remained bonded after the test interval was completed) were forcibly separated for visual evaluation. Figures 2A-2E show the post-test visual results for alloy reference A. Figure 2A shows bonded and then separated test coupons after no exposure to the neutral salt spray. Figure 2B shows bonded and then separated test coupons after 2 weeks of exposure to the neutral salt spray. Figure 2C shows bonded and then separated test coupons after 6 weeks of exposure to the neutral salt spray. Figure 2D shows bonded and then separated test coupons after 12 weeks of exposure to the neutral salt spray. Figure 2E shows bonded and then separated test coupons after 20 weeks of exposure to the neutral salt spray. Alloy reference A did not show a significant effect from the neutral salt spray test.

[0093] Figures 3A-3E show the post-test visible results for alloy reference B. Figure 3A shows the bonded and then separated test coupons after no exposure to neutral salt spray. Figure 3B shows the bonded and then separated test coupons after 2 weeks of exposure to neutral salt spray. Figure 3C shows the bonded and then separated test coupons after 6 weeks of exposure to neutral salt spray. Figure 3D shows the bonded and then separated test coupons after 12 weeks of exposure to neutral salt spray. Figure 3E shows the bonded and then separated test coupons after 20 weeks of exposure to neutral salt spray. Alloy reference B did not show a significant effect from the neutral salt spray test.

[0094] Figures 4A–4D show the post-test visible results for alloy reference C. Figure 4A shows the bonded and subsequently separated test coupons after no exposure to neutral salt spray. Figure 4B shows the bonded and subsequently separated test coupons after 6 weeks of exposure to neutral salt spray. Figure 4C shows the bonded and subsequently separated test coupons after 12 weeks of exposure to neutral salt spray. Figure 4D shows the bonded and subsequently separated test coupons after 20 weeks of exposure to neutral salt spray. Alloy reference C showed significant adhesive failure (e.g., failure at the interface between the adhesive and the metal) from the neutral salt spray test.

[0095] Figures 5A-5D show the visible results after testing for alloy reference D. Figure 5A shows the bonded and subsequently separated test coupons after no exposure to neutral salt spray. Figure 5B shows the bonded and subsequently separated test coupons after 6 weeks of exposure to neutral salt spray. Figure 5C shows the bonded and subsequently separated test coupons after 12 weeks of exposure to neutral salt spray. Figure 5D shows the bonded and subsequently separated test coupons after 20 weeks of exposure to neutral salt spray. Alloy reference D showed significant adhesive failure (e.g., failure at the interface between the adhesive and the metal) from the neutral salt spray test. Therefore, employing coatings corresponding to the main alloying elements in the metal can increase bond strength and bond durability.

[0096] As shown in Figures 2-5, applying Si-containing pretreatment to metals with excess Si (e.g., Figures 2 and 3, alloy references A and B, respectively) provided excellent bonding of the pretreatment to the metal surface. This superior bonding is demonstrated by adhesion fracture shown in Figures 2 and 3. Adhesion fracture is a fracture within the bulk of the adhesive, indicating that the bond of the adhesive to the metal is stronger than any internal bond within the adhesive. Such adhesive fracture is shown in Figures 4B-D and 5B-D, indicating that the bond of the adhesive to the metal deteriorated during the neutral salt spray test. Therefore, applying Si-containing pretreatment to metals with excess Si provided superior bonding durability compared to applying TiZr pretreatment to metals with excess Si.

[0097] All patents, publications, and abstracts cited above are incorporated herein by reference in their entirety. Various embodiments of the present invention are described in relation to achieving various objectives of the present invention. It should be recognized that these embodiments are merely illustrative of the principles of the present invention. Numerous modifications and adaptations thereof will be readily apparent to those skilled in the art without departing from the spirit and scope of the present invention as defined in the following claims. The invention relating to this disclosure includes the following aspects: <Aspect 1> Pre-treated metal articles, A first surface portion containing excess Si; and The surface pretreatment layer comprises one or more Si-containing compounds, The first surface portion or any one of the one or more Si-containing compounds contains O, A Si-O-Si bond interaction exists between the excess Si present in the first surface portion and the one or more Si-containing compounds present in the surface pretreatment layer. The pre-treated metal article wherein the surface pre-treatment layer is adhered to the first surface portion. <Aspect 2> The pre-treated metal article according to embodiment 1, wherein the excess Si is present in the first surface portion in an amount exceeding approximately 1.4% by weight. <Aspect 3> The pre-treated metal article according to embodiment 1 or 2, wherein the pre-treated metal article includes aluminum or an aluminum alloy, steel, magnesium or a magnesium alloy, titanium or a titanium alloy, copper or a copper alloy, any suitable metal or metal alloy, or any combination thereof. <Aspect 4> The pre-treated metal article according to any one of embodiments 1 to 3, wherein the pre-treated metal article is an aluminum alloy. <Aspect 5> The pre-treated metal article according to embodiment 4, wherein the aluminum alloy includes a 4xxx series aluminum alloy, a 5xxx series aluminum alloy, or a 6xxx series aluminum alloy. <Aspect 6> The pre-treated metal article according to any one of embodiments 1 to 5, wherein the pre-treated metal article is an automotive structural component, an aerospace structural component, a transport structural component, an automotive body component, an aerospace skin panel, a transport body component, an architectural component, an aesthetic component, an electronic device housing, or a beverage or food container. <Aspect 7> A method for joining a first metal to a second metal, To provide a first metal having a first surface portion containing excess Si; Forming a pre-treated surface portion of a first metal by applying a surface pre-treatment layer containing one or more Si-containing compounds to the first surface portion of the first metal, wherein either the first surface portion of the first metal or one or more of the Si-containing compounds contains O, and the application stimulates Si-O-Si bond interactions between the excess Si present in the first surface portion of the first metal and the one or more Si-containing compounds present in the surface pre-treatment layer; and This includes joining the pre-treated surface portion of the first metal to the surface of the second metal. The aforementioned method. <Aspect 8> Conditions (a)~(c): (a) The bond durability between the pre-treated surface portion of the first metal and the surface of the second metal is greater than the bond durability between (i) the surface portion of the metal pre-treated with a surface pretreatment that contains excess Si and does not contain one or more Si-containing compounds and (ii) the second metal; (b) The bond durability between the pre-treated surface portion of the first metal and the surface of the second metal is greater than the bond durability between (i) the surface portion of the metal pre-treated with a surface pretreatment that does not contain excess Si and contains one or more Si-containing compounds and (ii) the second metal; or (c) The bond durability between the pre-treated surface portion of the first metal and the surface of the second metal is greater than the bond durability between (i) the surface portion of the metal pre-treated with a surface pretreatment that does not contain excess Si and does not contain one or more Si-containing compounds and (ii) the second metal. The method according to embodiment 7, wherein one or more of the above are achieved. <Pattern 9> The method according to embodiment 7 or 8, wherein the first metal includes aluminum or an aluminum alloy, steel, magnesium or a magnesium alloy, titanium or a titanium alloy, copper or a copper alloy, any suitable metal or metal alloy, or any combination thereof. <Aspect 10> The method according to any one of embodiments 7 to 9, wherein the first metal includes an aluminum alloy. <Aspect 11> The method according to embodiment 10, wherein the aluminum alloy includes a 4xxx series aluminum alloy, a 5xxx series aluminum alloy, or a 6xxx series aluminum alloy. <Aspect 12> The method according to any one of embodiments 7 to 11, wherein the second metal includes aluminum or an aluminum alloy, steel, magnesium or a magnesium alloy, titanium or a titanium alloy, copper or a copper alloy, any suitable metal or metal alloy, or any combination thereof. <Aspect 13> The method according to any one of embodiments 7 to 12, wherein the excess Si is present in an amount exceeding approximately 1.4% by weight in at least the first surface portion of the first metal. <Aspect 14> The method according to any one of embodiments 7 to 13, further comprising etching at least the first surface portion of the first metal before the application. <Aspect 15> The method according to embodiment 14, wherein etching of at least the first surface portion of the first metal exposes Si in the first surface portion by removing a maximum of about 3 grams / square meter of surface material. <Aspect 16> The method according to any one of embodiments 7 to 15, further comprising cleaning at least the first surface portion of the first metal before the application. <Aspect 17> The method according to embodiment 16, wherein cleaning of at least the first surface portion of the first metal removes natural oxide or hydroxide species from at least the first surface portion of the first metal. <Aspect 18> The method according to any one of embodiments 7 to 17, wherein the surface pretreatment layer is applied to at least the first surface portion of the first metal, including bar coating, roll coating, spray coating, or dip coating. <Aspect 19> The method according to embodiment 18, further comprising curing the surface pretreatment layer. <Aspect 20> A joined metal structure prepared according to the method described in any one of embodiments 7 to 19. <Aspect 21> The bonded metal structure according to embodiment 20, wherein the bonded metal structure experiences a bond strength loss of less than 40% after 20 weeks of exposure to a neutral salt spray test.

Claims

1. Pre-treated metal articles, including aluminum alloys, A first surface portion containing excess Si; and The surface pretreatment layer comprises one or more Si-containing compounds, The first surface portion or any one of the one or more Si-containing compounds contains O, The Si-O-Si bond interaction exists between the excess Si present in the first surface portion and the one or more Si-containing compounds present in the surface pretreatment layer. The surface pretreatment layer is attached to the first surface portion, Excess Si is present in the first surface portion in an amount exceeding 1.4% by weight, and the excess Si content is calculated from the total Si content by Mg ２ The pre-treated metal article, calculated by subtracting the required amount of Si for the Si (Mg / 1.73) and Fe-containing phase (Fe / 3).

2. The pre-treated metal article according to claim 1, wherein the pre-treated metal article is an aluminum alloy.

3. The pre-treated metal article according to claim 2, wherein the aluminum alloy includes a 4xxx series aluminum alloy, a 5xxx series aluminum alloy, or a 6xxx series aluminum alloy.

4. The pre-treated metal article according to any one of claims 1 to 3, wherein the pre-treated metal article is an automotive structural component, an aerospace structural component, a transport structural component, an automotive body component, an aerospace skin panel, a transport body component, an architectural component, an aesthetic component, an electronic device housing, or a beverage or food container.

5. A method for joining a first metal containing an aluminum alloy to a second metal, To provide a first metal having a first surface portion containing excess Si; Forming a pre-treated surface portion of a first metal by applying a surface pre-treatment layer containing one or more Si-containing compounds to the first surface portion of the first metal, wherein either the first surface portion of the first metal or the one or more Si-containing compounds contains O, and the application promotes Si-O-Si bond interactions between the excess Si present in the first surface portion of the first metal and the one or more Si-containing compounds present in the surface pre-treatment layer; and The method involves joining the pre-treated surface portion of the first metal to the surface of the second metal, wherein excess Si is present in the first surface portion in an amount exceeding 1.4% by weight, and the excess Si content is calculated from the total Si content by Mg ２ The method described above is calculated by subtracting the amount of Si required for the Si (Mg / 1.73) and Fe-containing phase (Fe / 3).

6. Conditions (a) to (c): (a) The bond durability between the pre-treated surface portion of the first metal and the surface of the second metal is greater than the bond durability between (i) the surface portion of a metal pre-treated under the same conditions as the pre-treatment of the pre-treated surface portion of the first metal, except that the surface pre-treatment is of a metal containing excess Si and does not contain one or more Si-containing compounds, and (ii) the second metal; (b) The bond durability between the pre-treated surface portion of the first metal and the surface of the second metal is greater than the bond durability between (i) a surface portion of a metal that does not contain excess Si and is pre-treated under the same conditions as the pre-treatment of the pre-treated surface portion of the first metal with a surface pre-treatment containing one or more Si-containing compounds and (ii) the second metal; or (c) The bond durability between the pre-treated surface portion of the first metal and the surface of the second metal is greater than the bond durability between (i) the surface portion of the metal that is pre-treated under the same conditions as the pre-treatment of the pre-treated surface portion of the first metal, except that the surface treatment is free of excess Si and does not contain one or more Si-containing compounds, and (ii) the bond durability between the surface portion of the second metal and (ii) the surface portion of the second metal. One or more of the following are achieved: In conditions (a) to (c), Excess Si is present in the first surface portion in an amount exceeding 1.4% by weight. The method according to claim 5, wherein the surface pretreatment that does not contain one or more Si-containing compounds is a titanium-zirconium (TiZr) pretreatment.

7. The method according to claim 5 or 6, wherein the aluminum alloy includes a 4xxx-type aluminum alloy, a 5xxx-type aluminum alloy, or a 6xxx-type aluminum alloy.

8. The method according to any one of claims 5 to 7, wherein the second metal includes aluminum or an aluminum alloy, steel, magnesium or a magnesium alloy, titanium or a titanium alloy, copper or a copper alloy, or any combination thereof.

9. The method according to any one of claims 5 to 8, further comprising etching at least the first surface portion of the first metal before the application described above.

10. The method according to claim 9, wherein etching of at least the first surface portion of the first metal exposes Si in the first surface portion by removing up to 3 grams / square meter of surface material.

11. The method according to any one of claims 5 to 10, further comprising cleaning at least the first surface portion of the first metal before the application.

12. The method according to claim 11, wherein cleaning of at least the first surface portion of the first metal removes natural oxide or hydroxide species from at least the first surface portion of the first metal.

13. The method according to any one of claims 5 to 12, wherein applying the surface pretreatment layer to at least the first surface portion of the first metal includes bar coating, roll coating, spray coating, or dip coating.

14. The method according to claim 13, further comprising curing the surface pretreatment layer.

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