CN115427603A - Thermally modified oxide-based pretreatment for metals and method for producing said metals - Google Patents

Abstract

Provided herein are corrosion resistant metal substrates and methods of producing the corrosion resistant metal substrates by thermal modification. The present disclosure provides a method of producing a corrosion resistant substrate by producing a pre-treated film on a surface of a metal substrate and heating the pre-treated metal substrate. In particular, the metal substrate and/or the pretreated metal substrate of these methods is in an F temper, a T4 temper or a T6 temper.

Description

Thermally modified oxide-based pretreatment for metals and method for producing said metals

Cross Reference to Related Applications

This application claims priority and benefit of U.S. provisional patent application serial No. 63/015,056, filed 24/4/2020, which is incorporated herein by reference in its entirety.

Technical Field

The present disclosure relates generally to the processing of metal substrates, such as aluminum alloys. More specifically, the present disclosure relates to thermal modification of pretreated metal substrates.

Background

Certain metal products, such as aluminum alloys, may benefit from a pretreatment, such as the application or creation of a pretreatment film on the surface of the metal product. These benefits include bond durability, color stability, ease of maintenance, aesthetics, health and safety, and low cost. However, it is difficult to produce aluminum alloy coils with pre-treated films that meet flexibility, durability, and/or surface property requirements for downstream processing, including joining of aluminum alloy products. Furthermore, conventional methods require limiting the exposure of the pretreated metal to high temperatures, for example, to avoid losing the benefits described above. This limits the types of products that can be pretreated, such as tempering of aluminum alloys.

Disclosure of Invention

The embodiments encompassed by the present invention are defined by the claims, not this summary. This summary is a high-level overview of various aspects of the invention and is provided to introduce a selection of concepts that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used in isolation to determine the scope of the claimed subject matter. The subject matter should be understood with reference to appropriate portions of the entire specification, any or all figures, and each claim.

In one aspect, the present disclosure describes a method of manufacturing a corrosion resistant substrate, the method comprising producing a pretreatment film on a surface of a metal substrate to provide a pretreated metal substrate; and heating the pretreated metal substrate at a first temperature to provide the corrosion resistant substrate, wherein the first temperature is greater than 300 ℃; and wherein the metal substrate and/or the pretreated metal substrate is in an F temper, a T4 temper, or a T6 temper. In some cases, the metal substrate comprises an aluminum alloy (e.g., a 5xxx series aluminum alloy, a 6xxx series aluminum alloy, or a 7xxx series aluminum alloy). In some cases, the corrosion resistant substrate is in a T6 temper. In some cases, the pretreatment film includes an oxide layer. In some cases, the oxide layer includes aluminum oxide, silicon oxide, titanium oxide, chromium oxide, manganese oxide, nickel oxide, yttrium oxide, zirconium oxide, molybdenum oxide, or a combination thereof. In some cases, creating the pretreatment film comprises applying an inorganic pretreatment composition to the surface of the metal substrate. In some cases, creating the pre-treatment film comprises anodizing the surface of the metal substrate. In some cases, producing the pre-treatment film comprises flame hydrolyzing the surface of the metal substrate. In some cases, the first temperature is 300 ℃ to 550 ℃. In some cases, the heating comprises heating the pretreated metal substrate at the first temperature for less than 30 minutes. Optionally, the heating further comprises heating the pretreated metal substrate at a second temperature. In some cases, the second temperature is lower than the first temperature. In some cases, the second temperature is 75 ℃ to 250 ℃. In some cases, the heating comprises heating the pretreated metal substrate at the second temperature for 1 hour to 48 hours. In some cases, the metal substrate is a continuous coil.

In another aspect, the present disclosure describes a corrosion resistant coil comprising an aluminum alloy continuous coil, wherein a surface of the aluminum alloy continuous coil comprises an inorganic pretreatment film, and wherein the aluminum alloy continuous coil is in an F temper, a T4 temper, or a T6 temper. In some cases, the continuous coil of aluminum alloy comprises a 5xxx series aluminum alloy, a 6xxx series aluminum alloy, or a 7xxx series aluminum alloy. In some cases, the inorganic pre-treatment film comprises an oxide layer. In some cases, the oxide layer includes aluminum oxide, silicon oxide, titanium oxide, chromium oxide, manganese oxide, nickel oxide, yttrium oxide, zirconium oxide, molybdenum oxide, or a combination thereof.

In another aspect, the present disclosure describes a method of making a corrosion resistant substrate, the method comprising producing a pretreatment film on a surface of a metal substrate to provide a pretreated metal substrate; and heating the pretreated metal substrate at a first temperature to provide the corrosion resistant substrate, wherein the metal substrate and/or the pretreated metal substrate is in an F temper, and wherein the corrosion resistant substrate is in a T5 temper, a T6 temper, a T61 temper, a T7 temper, a T8x temper, or a T9 temper.

Drawings

The present disclosure is described in detail below with reference to the accompanying drawings.

Fig. 1 shows results from glow discharge emission spectroscopy (GDOES) analysis of corrosion resistant substrates according to certain aspects of the present disclosure.

Detailed Description

Methods for making corrosion resistant metal substrates, such as corrosion resistant aluminum alloy substrates, are described herein. For example, the corrosion resistant substrates described herein may be used to produce corrosion resistant products having superior surface quality and minimized surface defects as compared to products prepared from metal substrates that have not been processed according to the present disclosure.

Various pretreatments are often employed in the conventional processing of metal substrates (e.g., aluminum alloys). Some conventional processes produce a pre-treatment film on one or more surfaces of a metal substrate by chemical or electrolytic modification. The pre-treated film may alter the properties of the metal substrate, such as bond durability, adhesion, or corrosion rate. In conventional processes, the metal substrate is not thermally modified after pretreatment. In particular, conventional methods avoid exposing the pre-treatment film on the surface of the metal substrate to high temperatures (e.g., temperatures greater than 400 ℃). For example, conventional methods dry the pretreated surface at a temperature of less than 100 ℃. This is due to the common belief by those skilled in the art that exposure to high temperatures will degrade the pre-treated film, such as by burning or otherwise reducing the effectiveness of the pre-treated film. Furthermore, thermal modification of the metal substrate after pretreatment is considered an unnecessary additional cost to be avoided, since it is generally considered that exposure to high temperatures does not provide an advantage.

Although conventional concepts promote in other ways, the methods described herein include intentionally exposing the pre-treated membrane to elevated temperatures. The present disclosure provides a method of making a corrosion resistant metal substrate by creating a pre-treatment film on a surface of a metal substrate and heating the pre-treated metal substrate to a temperature greater than 400 ℃. Exposing the pre-treated membrane to high temperatures (e.g., greater than 400 ℃) according to the methods described herein does not degrade or adversely affect the pre-treated membrane. In contrast, high temperatures improve (e.g., enhance) the properties of the pre-treated film. Heating the pretreated metal substrate according to the present disclosure dries and/or densifies the pretreated film, thereby improving the bond durability, adhesion, and/or corrosion resistance imparted by the pretreated film.

Thus, the corrosion resistant substrates produced by the methods described herein exhibit excellent physical properties, such as bond durability. Furthermore, the process described herein is suitable for roll-to-roll lines (coil-to-coil lines) as well as batch processing.

Definition and description

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

In this specification, reference is made to alloys identified by aluminium industry designations such as "series" or "7 xxx". For an understanding of the most commonly used numerical designation system in naming and identifying Aluminum and its Alloys, see "International Alloy Designations and Chemical Composition Limits for Wrought Aluminum and Wrought Aluminum Alloys" or "Registration Record of Aluminum Association Alloy Designations and Chemical Composition Limits for Aluminum Alloys in cast and Ingot Form" (both issued by the American Aluminum Association).

As used herein, a plate typically has a thickness of greater than about 15 mm. For example, a plate may refer to an aluminum product having a thickness greater than 15mm, greater than 20mm, greater than 25mm, greater than 30mm, greater than 35mm, greater than 40mm, greater than 45mm, greater than 50mm, or greater than 100 mm.

As used herein, sauter board (also referred to as sheet board) typically has a thickness of about 4mm to about 15 mm. For example, the sauter board can have a thickness of 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, or 15 mm.

As used herein, sheet material generally refers to an aluminum product having a thickness of less than about 4 mm. For example, the sheet may have a thickness of less than 4mm, less than 3mm, less than 2mm, less than 1mm, less than 0.5mm, less than 0.3mm, or less than 0.1 mm.

As used herein, "bond durability" refers to the ability of an adhesive to bond two products together to withstand cyclic mechanical stresses after exposure to environmental conditions that cause the adhesive to fail. Bond durability is characterized by the number of mechanical stress cycles applied to the bonded product when the bonded product is exposed to ambient conditions until the bond fails.

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

As used herein, "roll-to-roll" line or "roll-to-roll processing" refers to a continuous processing method on a continuous line whereby an alloy (e.g., an aluminum alloy) processed in the method is fed into processing by a coil, uncoiled during processing, and recoiled after processing is completed. The alloy processed in such a processing method is referred to herein as a "continuous coil" or an "aluminum alloy continuous coil".

In this application reference is made to alloy conditions or tempers. For the most common alloy temper description, see "american national standards for alloys and temper nomenclature (ANSI) H35". The F temper refers to the aluminum alloy being produced. O temper or temper refers to the annealed aluminum alloy. T1 temper refers to an aluminum alloy that is cooled from hot working and naturally aged (e.g., at room temperature). T2 temper refers to an aluminum alloy that is cooled from hot working, cold worked, and naturally aged. T3 temper or temper refers to an aluminum alloy that has been solution heat treated, cold worked, and naturally aged. T4 temper refers to an aluminum alloy that has been solution heat treated and naturally aged. T5 temper or temper refers to an aluminum alloy that is cooled from hot working and artificially aged (at elevated temperatures). T6 temper or temper refers to an aluminum alloy that has been solution heat treated and artificially aged. T7 temper or temper refers to an aluminum alloy that has been solution heat treated and artificially over-aged. T8x temper refers to an aluminum alloy that has been solution heat treated, cold worked, and artificially aged. T9 temper or temper refers to an aluminum alloy that has been solution heat treated, artificially aged, and cold worked.

As used herein, the meaning of "a" or "an" includes both singular and plural referents unless the context clearly dictates otherwise.

As used herein, the modifier "about" is intended to include the term described without the word "about" (e.g., "about 10" is intended to include "10").

As used herein, "room temperature" can mean to include a temperature of about 15 ℃ to about 30 ℃, e.g., about 15 ℃, about 16 ℃, about 17 ℃, about 18 ℃, about 19 ℃, about 20 ℃, about 21 ℃, about 22 ℃, about 23 ℃, about 24 ℃, about 25 ℃, about 26 ℃, about 27 ℃, about 28 ℃, about 29 ℃, or about 30 ℃.

All ranges disclosed herein are to be understood to encompass any and all subranges subsumed therein. For example, a stated range of "1 to 10" should be considered to include any and all subranges between (and including 1 and 10) the minimum value of 1 and the maximum value of 10; that is, all subranges beginning with a minimum value of 1 or more (e.g., 1 to 6.1), and ending with a maximum value of 10 or less (e.g., 5.5 to 10).

Metal base material

As noted above, the present disclosure provides methods for manufacturing corrosion resistant metal substrates. More specifically, the methods described herein produce a pre-treatment film on the surface of a metal substrate. The composition of the metal substrate on which the pretreatment film is formed is not particularly limited. For example, the pre-treatment film may be applied to any suitable aluminum alloy, such as a continuous coil of aluminum alloy. Suitable aluminum alloys include, for example, 1xxx series aluminum alloys, 2xxx series aluminum alloys, 3xxx series aluminum alloys, 4xxx series aluminum alloys, 5xxx series aluminum alloys, 6xxx series aluminum alloys, 7xxx series aluminum alloys, and 8xxx series aluminum alloys.

As non-limiting examples, exemplary 1 xxx-series aluminum alloys for use as metal substrates may include AA1100, AA1100A, AA1200A, AA1300, AA1110, AA1120, AA1230A, AA1235, AA1435, AA1145, AA1345, AA1445, AA1150, AA1350A, AA1450, AA1370, AA1275, AA1185, AA1285, AA1385, AA1188, AA1190, AA1290, AA1193, AA1198, or AA1199. In some cases, the aluminum alloy is at least 99.9% pure aluminum (e.g., at least 99.91%, at least 99.92%, at least 99.93%, at least 99.94%, at least 99.95%, at least 99.96%, at least 99.97%, at least 99.98%, or at least 99.99% pure aluminum).

Non-limiting exemplary 2 xxx-series aluminum alloys for use as metal substrates may include AA2001, AA2002, AA2004, AA2005, AA2006, AA2007A, AA2007B, AA2008, AA2009, AA2010, AA2011A, AA2111A, AA2111B, AA2012, AA2013, AA2011 AA2014, AA2014A, AA2214, AA2015, AA2016, AA2017A, AA2117, AA2018, AA2218, AA2618A, AA2219, AA2319, AA2419, AA2519, AA2021, AA2022, AA2023, AA2024A, AA2124, AA2224A AA2324, AA2424, AA2524, AA2624, AA2724, AA2824, AA2025, AA2026, AA2027, AA2028A, AA2028B, AA2028C, AA2029, AA2030, AA2031, AA2032, AA2034, AA2036, AA2037, AA2038, AA2039, AA 2049, AA2040, AA2041, AA2044, AA2045, AA2050, AA2055, AA2060, AA2065, AA2070, AA2076, AA2090, AA2091, AA2094, AA2095, AA2195, AA2295, AA2196, AA2296, AA2097, AA2197, AA2297, AA2397, AA 238, AA2198, AA2099 or AA2199.

Non-limiting exemplary 3xxx series aluminum alloys for use as the metal substrate may include AA3002, AA3102, AA3003, AA3103A, AA3103B, AA3203, AA3403, AA3004A, AA3104, AA3204, AA3304, AA3005A, AA3105A, AA3105B AA3007, AA3107, AA3207A, AA3307, AA3009, AA3010, AA3110, AA3011, AA3012A, AA3013, AA3014, AA3015, AA3016, AA3017, AA3019, AA3020, AA3021, AA3025, AA3026, AA3030, AA3130, or AA3065.

Non-limiting exemplary 4 xxx-series aluminum alloys for use as metal substrates may include AA4004, AA4104, AA4006, AA4007, AA4008, AA4009, AA4010, AA4013, AA4014, AA4015A, AA4115, AA4016, AA4017, AA4018, AA4019, AA4020, AA4021, AA4026, AA4032, AA4043A, AA4143, AA4343, AA4643, AA4943, AA4044, AA4045, AA4145A, AA4046, AA4047A, or AA4147.

<xnotran> 5xxx AA5182, AA5183, AA5005, AA5005A, AA5205, AA5305, AA5505, AA5605, AA5006, AA5106, AA5010, AA5110, AA5110A, AA5210, AA5310, AA5016, AA5017, AA5018, AA5018A, AA5019, AA5019A, AA5119, AA5119A, AA5021, AA5022, AA5023, AA5024, AA5026, AA5027, AA5028, AA5040, AA5140, AA5041, AA5042, AA5043, AA5049, 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, AA5554, AA5654, AA5654A, AA5754, AA5854, AA5954, AA5056, AA5356, AA5356A, AA5456, AA5456A, AA5456B, AA5556, AA5556A, AA5556B, AA5556C, AA5257, AA5457, AA5557, AA5657, AA5058, AA5059, AA5070, AA5180, AA5180A, AA5082, AA5182, AA5083, AA5183, AA5183A, AA5283, AA5283A, AA5283B, AA5383, AA5483, AA5086, AA5186, AA5087, AA5187 AA5088. </xnotran>

<xnotran> 6xxx AA6101, AA6101A, AA6101B, AA6201, AA6201A, AA6401, AA6501, AA6002, AA6003, AA6103, AA6005, AA6005A, AA6005B, AA6005C, AA6105, AA6205, AA6305, AA6006, AA6106, AA6206, AA6306, 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, AA6028, AA6031, AA6032, AA6033, AA6040, AA6041, AA6042, AA6043, AA6151, AA6351, AA6351A, AA6451, AA6951, AA6053, AA6055, AA6056, AA6156, AA6060, AA6160, AA6260, AA6360, AA6460, AA6460B, AA6560, AA6660, AA6061, AA6061A, AA6261, AA6361, AA6162, AA6262, AA6262A, AA6063, AA6063A, AA6463, AA6463A, AA6763, A6963, AA6064, AA6064A, AA6065, AA6066, AA6068, AA6069, AA6070, AA6081, AA6181, AA6181A, AA6082, AA6082A, AA6182, AA6091 AA6092. </xnotran>

Non-limiting exemplary 7 xxx-series aluminum alloys for use as metal substrates may include AA7011, AA7019, AA7020, AA7021, AA7039, AA7072, AA7075, AA7085, AA7108A, AA7015, AA7017, AA7018, AA7019A, AA7024, AA7025, AA7028, AA7030, AA7031, AA7033, AA7035A, AA7046A, AA7003, AA7004, AA7005, AA7009, AA7010, AA7011, AA7012, AA7014, AA7016, AA7116, AA7122, AA7023, AA7026, AA7029, AA709, AA7009, AA7010, AA7011, AA7012, AA7014, AA7016, AA7116, AA7122, AA7023, AA7026, AA7029, AA7014, AA7017, AA709, AA AA7129, AA7229, AA7032, AA7033, AA7034, AA7036, AA7136, AA7037, AA7040, AA7140, AA7041, AA7049A, AA7149, AA7204, AA7249, AA7349, AA7449, AA7050A, AA7150, AA7250, AA7055, AA7155, AA7255, AA7056, AA7060, AA7064, AA7065, AA7068, AA7168, AA7175, AA7475, AA7076, AA7178, AA7278A, AA7081, AA7185, AA7090, AA7093, AA7095 or AA7099.

Non-limiting exemplary 8xxx series aluminum alloys for use as metal substrates may include AA8005, AA8006, AA8007, AA8008, AA8010, AA8011A, AA8111, AA8211, AA8112, AA8014, AA8015, AA8016, AA8017, AA8018, AA8019, AA8021A, AA8021B, AA8022, AA8023, AA8024, AA8025, AA8026, AA8030, AA8130, AA8040, AA8050, AA8150, AA8076A, AA8176, AA8077, AA8177, AA8079, AA8090, AA8091, or AA8093.

Although aluminum alloy products are described throughout the disclosure, the methods and products are applicable to any metal substrate. In some embodiments, the metal substrate is aluminum, an aluminum alloy, magnesium, a magnesium-based material, titanium, a titanium-based material, copper, a copper-based material, steel, a steel-based material, bronze, a bronze-based material, brass, a brass-based material, a composite material, a sheet used in a composite material, or any other suitable metal or combination of materials. The product may include monolithic materials as well as non-monolithic materials, such as roll bonded materials, clad materials, composite materials, or various other materials. In some examples, the metal substrate is a metal coil, metal strip, metal plate, metal sauter plate, metal sheet, metal billet, metal ingot, or other metal article.

The alloys may be produced by direct chill casting (including direct chill co-casting) or semi-continuous casting, continuous casting (including, for example, by using a twin belt caster, twin roll caster, block caster or any other continuous caster), electromagnetic casting, hot top casting or any other casting method.

The metal substrate may be made of any tempered alloy. In some embodiments, the metal substrate is an alloy in an F temper, a T4 temper, or a T6 temper. As described below, the temper of the metal substrate may be altered by the thermal modification described herein. In one embodiment of the method, for example, a metal substrate is provided in an F temper, a pretreatment film is produced on a surface of the metal substrate, and the pretreated metal substrate is heated such that the final corrosion resistant substrate is in a T6 temper without damaging the pretreatment film.

Pretreatment of

The methods described herein include producing a pretreatment film on a surface of a metal substrate to provide a pretreated metal substrate. The pre-treated films described herein improve the properties, such as adhesion and/or corrosion resistance, of the metal substrate on the surface of which the pre-treated film is produced.

The method of producing the pretreatment film on the surface of the metal substrate is not particularly limited, and any suitable method known in the art may be used. In some embodiments, creating a pretreatment film can include applying a pretreatment composition (e.g., an inorganic pretreatment composition) to a surface of a metal substrate. In some cases, for example, a pretreatment composition (e.g., an inorganic pretreatment composition) can be sprayed onto the surface of a metal substrate. In some cases, the metal substrate can be immersed in a pretreatment composition (e.g., an inorganic pretreatment composition). The pretreatment composition (e.g., an inorganic pretreatment composition) can be specifically formulated to produce a pretreatment film on the surface of the metal substrate. For example, the pretreatment composition can include chromium, molybdenum, titanium, zirconium, manganese, or combinations thereof.

In some embodiments, creating the pretreatment film can include anodizing the surface of the metal substrate. Anodizing may include, for example, contacting a surface of a metal substrate with an electrolyte solution and applying an electrical current (e.g., alternating Current (AC) power and/or Direct Current (DC)) to the metal substrate. In some cases, anodizing the metal substrate produces a pretreated metal substrate having a thin pretreatment film, which may include an oxide layer. Suitable methods for anodization are described in U.S. publication No. 2020/0082972, which is incorporated by reference herein.

In some embodiments, creating the pre-treatment film may comprise a pyrolysis process. For example, the pre-treatment film may be produced by flame pyrolysis deposition. Flame pyrolysis deposition can include burning (e.g., combusting) metal products to produce deposits on the surface of the metal substrate. The composition of the deposit will vary with the gas mixture and/or metal compound that may be specifically formulated for flame pyrolysis deposition. In some cases, the deposit, which may include an oxide, forms a pretreatment film.

The composition or structure of the pretreatment film on the pretreated metal substrate is not particularly limited, and any pretreatment film known in the art may be produced or used. The pretreatment membrane known in the art can be classified into an organic pretreatment membrane, an inorganic pretreatment membrane, and a combined pretreatment membrane. The organic pretreatment membrane comprises an organic compound (i.e., a carbon-containing compound), such as an organic polymer. The inorganic pretreatment film comprises inorganic compounds (i.e., non-carbon containing compounds), such as metal ion analogs and metal coordination complexes. The combined pretreatment membrane comprises both an organic compound and an inorganic compound or an organic-inorganic compound comprising both an organic moiety and an inorganic moiety.

In some embodiments, the pre-treatment film produced in the disclosed methods is an organic pre-treatment film. Preferably, however, the pre-treated membrane is an inorganic pre-treated membrane or a combination pre-treated membrane. As described herein, thermal modification (discussed below) of a metal substrate that has been pretreated with an inorganic and/or combination pretreatment film unexpectedly improves the properties (e.g., adhesion, corrosion resistance) of the metal substrate. In contrast, the present inventors have found that thermal modification of a metal substrate that has been pretreated with an organic pretreatment film may not improve properties (e.g., may not improve properties to the same extent). In some cases, thermal modification of metal substrates with organic pretreatment films may even reduce the properties of the substrate. In theory, organic compounds present in conventional organic pre-treatment films (e.g., organic polymers) may undergo undesirable chemical reactions (e.g., combustion) when subjected to the thermal modification described herein. Thus, in some embodiments of the method, the pre-treatment film is not an organic pre-treatment film (i.e., a pre-treatment film comprising only organic compounds).

In some cases, creating a pretreatment film on a surface of a metal substrate includes creating an oxide layer on the surface. In other words, the pretreatment film may include an oxide layer. For example, the pretreatment film may include an inorganic oxide layer. The oxide layer includes one or more oxides, such as metal oxides.

The composition of the oxide layer is not particularly limited, and may be usedAny suitable oxide layer known in the art. The oxide layer can include, for example, alumina (e.g., al) ₂ O, alO and/or Al ₂ O ₃ ) Silicon oxide (e.g., siO) ₂ And/or SiO), titanium oxide (e.g., ti) ₂ O、TiO、Ti ₂ O ₃ And/or TiO ₂ ) Chromium oxide (e.g., crO, cr) ₂ O ₃ 、CrO ₂ And/or CrO ₅ ) Manganese oxide (e.g., mnO, mn) ₃ O ₄ 、Mn ₂ O ₃ 、MnO ₂ 、MnO ₃ And/or Mn ₂ O ₇ ) Nickel oxide (e.g., niO and/or Ni) ₂ O ₃ ) Yttrium oxide (e.g., Y) ₂ O ₃ ) Zirconium oxide (e.g., zrO) ₂ ) Molybdenum oxide (e.g., moO) ₂ And/or MoO ₃ ) Or a combination thereof.

In some embodiments, the pretreatment film comprises an oxide layer of aluminum oxide. In some embodiments, the pre-treatment film comprises an oxide layer of silicon oxide. In some embodiments, the pretreatment film comprises a combination of oxides. For example, the pretreatment film may include oxide layers of titanium oxide and zirconium oxide.

Typically, the pretreatment film comprises a thin layer on a portion (e.g., at least a portion) of the surface of the metal substrate. In some cases, a pretreatment film may be produced on one surface of a metal substrate. In some cases, the pretreatment film can be produced on one or more surfaces, e.g., both surfaces, of the metal substrate. In some cases, the pre-treatment film is produced on all surfaces of the metal substrate.

The thickness of the pre-treatment film may vary. As noted above, the pre-treatment film is typically a thin layer. The thickness of the pre-treatment film may range from about 1nm to about 1000 nm. In some cases, the thickness of the pre-treatment film is less than about 1000nm, for example, less than about 900nm, less than about 800nm, less than about 700nm, less than about 600nm, less than about 500nm, less than about 400nm, less than about 300nm, less than about 200nm, or less than about 100nm. For example, the thickness of the pre-treatment film may be about 5nm to about 1000nm, about 10nm to about 900nm, about 20nm to about 800nm, or about 30nm to about 700nm. In some examples, the thickness of the pre-treatment film may be about 1nm, about 5nm, about 10nm, about 15nm, about 20nm, about 25nm, about 30nm, about 35nm, about 40nm, about 45nm, about 50nm, about 55nm, about 60nm, about 65nm, about 70nm, about 75nm, about 80nm, about 85nm, about 90nm, about 95nm, about 100nm, about 150nm, about 200nm, about 250nm, about 300nm, about 400nm, about 500nm, about 600, about 700nm, about 750nm, about 800nm, about 850nm, about 900nm, about 950nm, or about 1000nm, or any value therebetween.

In some cases, the pre-treatment film on the pre-treated metal substrate may consist of multiple layers. In particular, certain methods of producing a pre-treated film may produce different layers within the pre-treated film. For example, anodizing a metal substrate can produce a pretreatment film that includes a barrier layer (e.g., composed of alumina, such as non-porous alumina) and a filament layer (e.g., composed of alumina, such as porous alumina). The properties of any one layer can be controlled by the method of producing the pre-treatment film (e.g., anodization parameters or conditions).

The tempering of the substrate is generally not affected (e.g., altered) by the production of the pre-treated film. That is, the pretreated metal substrate is typically in the same temper as the metal substrate prior to pretreatment. In some embodiments, the pretreated metal substrate is an alloy in an F temper, a T4 temper, or a T6 temper. As described below, the temper of the metal substrate may be altered by the thermal modification described herein. In one embodiment, for example, the pretreated metal substrate is in an F temper and thermal modification of the pretreated metal substrate produces a substrate in a T6 temper.

Thermal modification

The methods described herein include heating a pretreated metal substrate to provide a corrosion resistant substrate. As described above, conventional methods of pretreating metal substrates avoid exposing the metal substrate to high temperatures (e.g., temperatures greater than 400 ℃) after the pretreatment film is produced. One of ordinary skill in the art would recognize that exposure to high temperatures would degrade or otherwise reduce the effectiveness of the pre-treated membrane. In contrast, heating the pretreated metal substrate according to the methods described herein strengthens the pretreated film.

The thermal modification of the present disclosure includes heating the pretreated metal substrate at a first temperature, which is typically an elevated temperature relative to conventional processes. In some embodiments, the first temperature is 300 ℃ to 550 ℃, e.g., 300 ℃ to 540 ℃,300 ℃ to 530 ℃,300 ℃ to 520 ℃,300 ℃ to 510 ℃,300 ℃ to 500 ℃, 325 ℃ to 550 ℃, 325 ℃ to 540 ℃, 325 ℃ to 530 ℃, 325 ℃ to 520 ℃, 325 ℃ to 510 ℃, 325 ℃ to 500 ℃, 350 ℃ to 550 ℃, 350 ℃ to 540 ℃, 350 ℃ to 530 ℃, 350 ℃ to 520 ℃, 350 ℃ to 510 ℃, 350 ℃ to 500 ℃, 375 ℃ to 550 ℃, 375 ℃ to 530 ℃, 375 ℃ to 520 ℃, 375 ℃ to 510 ℃, 400 ℃ to 550 ℃, 400 ℃ to 540 ℃, 400 ℃ to 530 ℃, 400 ℃ to 510 ℃, 400 ℃ to 500 ℃, 425 ℃ to 550 ℃, 425 ℃ to 540 ℃, 425 ℃ to 530 ℃, 425 ℃ to 510 ℃, 425 ℃ to 500 ℃, 450 ℃ to 540 ℃, 450 ℃ to 530 ℃, 450 ℃ to 450 ℃, or 450 ℃ to 500 ℃.

As an upper limit, the first temperature may be less than 550 ℃, such as less than 540 ℃, less than 530 ℃, less than 520 ℃, less than 510 ℃, or less than 500 ℃. With respect to the lower limit, the first temperature may be greater than 300 ℃, e.g., greater than 325 ℃, greater than 350 ℃, greater than 375 ℃, greater than 400 ℃, greater than 425 ℃, or greater than 450 ℃.

In some cases, the first temperature can be about 375 ℃, about 385 ℃, about 395 ℃, about 400 ℃, about 405 ℃, about 410 ℃, about 415 ℃, about 420 ℃, about 425 ℃, about 430 ℃, about 435 ℃, about 440 ℃, about 445 ℃, about 450 ℃, about 455 ℃, about 460 ℃, about 465 ℃, about 466 ℃, about 467 ℃, about 468 ℃, about 469 ℃, about 470 ℃, about 471 ℃, about 472 ℃, about 473 ℃, about 475 ℃, about 476 ℃, about 477 ℃, about 478 ℃, about 479 ℃, about 480 ℃, about 481 ℃, about 482 ℃, about 483 ℃, about 484 ℃, about 485 ℃, about 486 ℃, about 487 ℃, about 488 ℃, about 489 ℃, about 490 ℃, about 491 ℃, about 492 ℃, about 493 ℃, about 494 ℃, about 495 ℃, about 496 ℃, about 497 ℃, about 499 ℃, about 500 ℃, about 510 ℃, about 520 ℃, about 525 ℃, about 530 ℃, about 540 ℃, or any temperature therebetween.

Thermal modification of the described methods may include prolonged exposure to an elevated temperature, such as the first temperature. Prolonged exposure to elevated temperatures may enhance the pre-treated film, for example by (further) drying and/or densifying the pre-treated film. Thus, in some embodiments, the pretreated metal substrate can be heated at a first temperature for a period of time.

In some embodiments, the pretreated metal substrate is heated at the first temperature for a period of time from 10 seconds to 30 minutes, such as from 10 seconds to 25 minutes, from 10 seconds to 20 minutes, from 10 seconds to 15 minutes, from 10 seconds to 10 minutes, from 15 seconds to 30 minutes, from 15 seconds to 25 minutes, from 15 seconds to 20 minutes, from 15 seconds to 15 minutes, from 15 seconds to 10 minutes, from 30 seconds to 30 minutes, from 30 seconds to 25 minutes, from 30 seconds to 20 minutes, from 30 seconds to 15 minutes, from 30 seconds to 10 minutes, from 60 seconds to 30 minutes, from 60 seconds to 25 minutes, from 60 seconds to 20 minutes, from 60 seconds to 15 minutes, from 75 seconds to 30 minutes, from 75 seconds to 20 minutes, from 75 seconds to 15 minutes, from 75 seconds to 10 minutes, from 90 seconds to 30 minutes, from 90 seconds to 25 minutes, from 90 seconds to 20 minutes, from 90 seconds to 15 minutes, or from 90 seconds to 10 minutes.

As an upper limit, the pretreated metal substrate can be heated at the first temperature for less than 30 minutes, such as less than 25 minutes, less than 20 minutes, less than 15 minutes, or less than 10 minutes. With respect to the lower limit, the pretreated metal substrate can be heated at the first temperature for at least 10 seconds, such as at least 15 seconds, at least 30 seconds, at least 60 seconds, at least 75 seconds, or at least 90 seconds.

In some cases, for example, the pretreated metal substrate is heated at the first temperature for about 1 minute, about 2 minutes, about 3 minutes, about 4 minutes, about 5 minutes, about 6 minutes, about 7 minutes, about 8 minutes, about 9 minutes, or about 10 minutes, or any length of time therebetween.

In some embodiments, the first temperature may be maintained during the period of time by a suitable heating process. In some cases, for example, heat may be applied to the pretreated metal substrate continuously and/or continuously over the period of time.

In some embodiments, the first temperature may be maintained during the period of time. In some cases, for example, the pretreated metal substrate can be exposed to a first temperature, and no additional heat can be applied during the time period, such that the temperature to which the pretreated metal substrate is heated during the time period can be slightly reduced, e.g., by less than 25 ℃, less than 20 ℃, less than 15 ℃, less than 10 ℃, less than 5 ℃, less than 3 ℃, less than 2 ℃, or less than 1 ℃.

In some embodiments, the thermal modification comprises an additional heating step. For example, the pretreated metal substrate can be heated at a second temperature (e.g., before and/or after heating at the first temperature). In some cases, heating at the second temperature further strengthens the pre-treated film, for example by drying and/or densifying the pre-treated film, according to the described method. Thus, the corrosion resistant substrate may exhibit improved adhesion, bond durability, and/or corrosion resistance.

The second temperature is typically a higher temperature relative to conventional processes. The second temperature may or may not be related to the first temperature. In some embodiments, for example, the second temperature is less than the first temperature. In some embodiments, the first temperature and the second temperature are about the same.

In some embodiments, the second temperature is 75 ℃ to 250 ℃, e.g., 75 ℃ to 240 ℃, 75 ℃ to 230 ℃, 75 ℃ to 220 ℃, 75 ℃ to 210 ℃, 75 ℃ to 200 ℃, 80 ℃ to 250 ℃, 80 ℃ to 240 ℃, 80 ℃ to 230 ℃, 80 ℃ to 220 ℃, 80 ℃ to 210 ℃, 80 ℃ to 200 ℃, 85 ℃ to 250 ℃, 85 ℃ to 240 ℃, 85 ℃ to 230 ℃, 85 ℃ to 210 ℃, 85 ℃ to 200 ℃, 90 ℃ to 250 ℃, 90 ℃ to 240 ℃, 90 ℃ to 230 ℃, 90 ℃ to 220 ℃, 90 ℃ to 210 ℃, 90 ℃ to 200 ℃, 95 ℃ to 250 ℃, 95 ℃ to 240 ℃, 95 ℃ to 230 ℃, 95 ℃ to 220 ℃, 95 ℃ to 210 ℃, 100 ℃ to 230 ℃, 100 ℃ to 220 ℃, 100 ℃ to 210 ℃, or 100 ℃ to 200 ℃. In some embodiments, the second temperature is 150 ℃ to 250 ℃, e.g., 150 ℃ to 240 ℃, 150 ℃ to 230 ℃, 150 ℃ to 220 ℃, 150 ℃ to 210 ℃, 150 ℃ to 200 ℃, 155 ℃ to 250 ℃, 155 ℃ to 240 ℃, 155 ℃ to 230 ℃, 155 ℃ to 220 ℃, 155 ℃ to 210 ℃, 155 ℃ to 200 ℃, 160 ℃ to 250 ℃, 160 ℃ to 240 ℃, 160 ℃ to 230 ℃, 160 ℃ to 220 ℃, 160 ℃ to 210 ℃, 160 ℃ to 200 ℃, 165 ℃ to 250 ℃, 165 ℃ to 240 ℃, 165 ℃ to 230 ℃, 165 ℃ to 220 ℃, 165 ℃ to 210 ℃, 165 ℃ to 200 ℃, 170 ℃ to 250 ℃, 170 ℃ to 230 ℃, 170 ℃ to 220 ℃, 170 ℃ to 210 ℃, 170 ℃ to 200 ℃, 175 ℃ to 250 ℃, 175 ℃ to 240 ℃, 175 ℃ to 230 ℃, 175 ℃ to 220 ℃, 175 ℃ to 210 ℃, 175 ℃ to 200 ℃, 180 ℃ to 250 ℃, 180 ℃ to 240 ℃, 180 ℃ to 230 ℃, 180 ℃ to 210 ℃, 180 ℃ to 200 ℃ or 180 ℃ to 200 ℃.

With respect to the upper limit, the second temperature may be less than 250 ℃, e.g., less than 240 ℃, less than 230 ℃, less than 220 ℃, less than 210 ℃, or less than 200 ℃. With respect to the lower limit, the second temperature may be greater than 75 ℃, e.g., greater than 80 ℃, greater than 85 ℃, greater than 90 ℃, greater than 95 ℃, or greater than 100 ℃.

In some cases, for example, the second temperature can be about 90 ℃, about 91 ℃, about 92 ℃, about 93 ℃, about 94 ℃, about 95 ℃, about 96 ℃, about 97 ℃, about 98 ℃, about 99 ℃, about 100 ℃, about 101 ℃, about 102 ℃, about 103 ℃, about 104 ℃, about 105 ℃, about 106 ℃, about 107 ℃, about 108 ℃, about 109 ℃, about 110 ℃, about 111 ℃, about 112 ℃, about 113 ℃, about 114 ℃, about 115 ℃, about 116 ℃, about 117 ℃, about 118 ℃, about 119 ℃, about 120 ℃, about 121 ℃, about 122 ℃, about 123 ℃, about 124 ℃, about 125 ℃, about 126 ℃, about 127 ℃, about 128 ℃, about 129 ℃, about 130 ℃, about 131 ℃, about 132 ℃, about 133 ℃, about 134 ℃, about 135 ℃, about 136 ℃, about 137 ℃, about 138 ℃, about 139 ℃, about 140 ℃, about 141 ℃, about 142 ℃, about 143 ℃, about 144 ℃, about 145 ℃, about 146 ℃, about 147 ℃, about 148 ℃, about 149 ℃, or about 150 ℃, or any temperature therebetween.

As with the first temperature, in some cases, the pretreated metal substrate can be heated at the second temperature for an extended period of time. In some embodiments, the pretreated metal substrate is heated at the second temperature for a period of time greater than the time it is exposed to the first temperature. In some embodiments, the pretreated metal substrate is heated at the second temperature for a period of time less than the time it is exposed to the first temperature. In some embodiments, the pretreated metal substrate is exposed to the first temperature and the second temperature for about the same amount of time.

In some embodiments, the pretreated metal substrate is heated at the second temperature for a period of 1 hour to 48 hours, such as 1 hour to 42 hours, 1 hour to 38 hours, 1 hour to 34 hours, 1 hour to 30 hours, 2 hours to 48 hours, 2 hours to 42 hours, 2 hours to 38 hours, 2 hours to 34 hours, 2 hours to 30 hours, 4 hours to 48 hours, 4 hours to 42 hours, 4 hours to 38 hours, 4 hours to 34 hours, 4 hours to 30 hours, 8 hours to 48 hours, 8 hours to 42 hours, 8 hours to 38 hours, 8 hours to 34 hours, 8 hours to 30 hours, 12 hours to 48 hours, 12 hours to 42 hours, 12 hours to 38 hours, 12 hours to 34 hours, 12 hours to 30 hours, 18 hours to 48 hours, 18 hours to 42 hours, 18 hours to 38 hours, 18 hours to 34 hours, 18 hours to 30 hours, 22 hours to 48 hours, 22 hours to 42 hours, 22 hours to 38 hours, 22 hours to 30 hours, or 22 hours.

For an upper limit, the pretreated metal substrate can be heated at the second temperature for less than 48 hours, such as less than 42 hours, less than 38 hours, less than 34 hours, or less than 30 hours. With respect to the lower limit, the pretreated metal substrate can be heated at the second temperature for at least 1 hour, e.g., at least 2 hours, at least 4 hours, at least 8 hours, at least 12 hours, at least 18 hours, or at least 22 hours.

In some cases, for example, the pretreated metal substrate is heated at the second temperature for about 18 hours, about 19 hours, about 20 hours, about 21 hours, about 22 hours, about 23 hours, about 24 hours, about 25 hours, about 26 hours, about 27 hours, about 28 hours, about 29 hours, about 30 hours, about 31 hours, or about 32 hours, or any length of time therebetween.

As with the first temperature, in some embodiments, the second temperature may be maintained during the period of time by a suitable heating process. In some cases, for example, heat may be applied to the pretreated metal substrate continuously and/or continuously over a period of time. In some embodiments, the second temperature may be maintained during the period of time. In some cases, for example, the pretreated metal substrate can be exposed to the second temperature, and no additional heat can be applied during the time period, such that the temperature to which the pretreated metal substrate is heated during the time period can be slightly reduced, e.g., by less than 25 ℃, less than 20 ℃, less than 15 ℃, less than 10 ℃, less than 5 ℃, less than 3 ℃, less than 2 ℃, or less than 1 ℃.

The thermal modification of the described method can artificially age the pretreated metal substrate. That is, the corrosion resistant substrate produced by the methods described herein may be an artificially aged alloy. For example, artificial aging may be achieved by heating the pretreated metal substrate at only a first temperature and/or by heating the pretreated metal substrate at both a first temperature and a second temperature.

By artificially aging the pretreated metal substrate, the thermal modification described herein produces a corrosion resistant substrate that is in a different temper than the metal substrate and/or the tempering of the pretreated metal substrate. In some embodiments, for example, the metal substrate is in an F temper or a T4 temper, and the thermal modification produces a substrate in a T6 temper. Further discussion of tempering of corrosion resistant substrates is provided below.

Corrosion resistant substrate

The methods described herein produce corrosion resistant substrates. In particular, the method produces a corrosion resistant substrate having a pretreatment film (e.g., a reinforced pretreatment film, such as a dried pretreatment film or a densified pretreatment film). The pre-treated film imparts desirable properties to the corrosion resistant substrate, such as corrosion resistance and/or increased adhesion. As a result of the described methods, the corrosion resistant substrates exhibit excellent bond durability, adhesion, and/or corrosion resistance.

In some embodiments, the thermal modification does not alter (e.g., chemically alter) the pre-treated film. In some cases, for example, the chemical composition of the pre-treated film is not substantially altered by thermal modification. In some cases, the thermal modification dries (e.g., removes adsorbed and/or absorbed water) the pre-treated membrane. The pre-treatment film of the corrosion resistant substrate may include an oxide layer. For example, the pretreatment film of the corrosion resistant substrate may include an inorganic oxide layer. The oxide layer includes one or more oxides, such as metal oxides. In particular, the pretreatment film of the corrosion resistant substrate can include any of the above oxides or combinations thereof.

In some cases, exposing the aluminum alloy to high temperatures results in surface enrichment of certain alloying elements. For example, high temperatures often result in surface enrichment of magnesium and/or silicon, which can lead to corrosion. Surface enrichment of these and other elements is not an issue for the thermal modification of the present disclosure, as the pre-treated film (e.g., oxide layer) can act as a barrier.

In some cases, the physical structure of the pre-treated film after thermal modification is not altered compared to the physical structure of the pre-treated film before thermal modification as described herein. In some cases, the thermal modification forms metal oxide bridges, resulting in a dense anhydrous oxide film. As described above, the pretreatment film on the pretreated metal substrate may be composed of a plurality of layers. These layers may remain intact after thermal modification. For example, the corrosion resistant substrate can include a pretreatment film comprising a barrier layer (e.g., composed of alumina, such as non-porous alumina) and a filament layer (e.g., composed of alumina, such as porous alumina).

As described above, thermal modification can artificially age pretreated metal substrates. Thus, the corrosion resistant substrate may be in a temper corresponding to artificially aged alloys. In some embodiments, the corrosion resistant substrate is in a T5 temper, a T6 temper, a T61 temper, a T7 temper, a T8x temper, or a T9 temper. In some cases, in particular, the corrosion resistant substrate may be in a T6 temper.

Use of corrosion-resistant substrates

Corrosion resistant substrates made according to the methods described herein can be used to produce products, including products particularly for use in automotive, electronics, and transportation applications, such as commercial vehicles, aircraft, or railroad applications. The continuous webs and processes described herein provide products with surface properties that are desirable in a variety of applications. The products described herein may have high strength, high deformability (elongation, stamping, forming, formability, bendability, or thermoformability), and/or high corrosion resistance. The corrosion resistant substrate is prepared as a continuous web providing deformability without damaging the pre-treated product.

In certain aspects, the corrosion resistant substrate may be coated, for example, zn-phosphatizing and electrocoating (E-coating). The corrosion resistant substrate exhibits improved coating adhesion compared to a continuous web without the pretreatment film.

In some other aspects, the corrosion resistant substrate exhibits a high level of adhesion of the laminate or paint film on the surface of the continuous web. Furthermore, the laminate and lacquer may be post-cured at temperatures up to about 230 ℃ when applied. The high temperatures used in certain downstream processing of the aluminum alloy product do not damage the corrosion resistant substrate, thereby providing the aluminum alloy product with a heat resistant pretreatment.

In some other aspects, the corrosion resistant substrate exhibits excellent adhesion durability.

In some examples, corrosion resistant substrates may be used for the chassis, cross-members, and components within the chassis (including but not limited to all components between two C-channels in a commercial vehicle chassis) to enhance strength, thereby becoming a complete or partial replacement for high strength steel. In certain aspects, the corrosion resistant substrate can be used to prepare automotive body part products, for example automotive body parts such as bumpers, side sills, roof rails, cross-members, pillar reinforcements (e.g., a-pillars, B-pillars, and C-pillars), interior panels, side panels, bottom panels, tunnels, structural panels, gusset panels, inner covers, or trunk lids. The disclosed corrosion resistant substrates may also be used in aircraft or railway vehicle applications to make, for example, exterior and interior panels.

In some examples, the corrosion resistant substrates can also be used to prepare housings for electronic devices, including mobile phones and tablet computers. For example, corrosion resistant substrates can be used to prepare housings for covers for mobile phones (e.g., smart phones) and tablet chassis. Exemplary consumer electronics include mobile phones, audio devices, video devices, cameras, laptop computers, desktop computers, tablet computers, televisions, displays, home appliances, video playback and recording devices, and the like. Exemplary consumer electronic parts include a housing (e.g., front side) and internal components for a consumer electronic product.

The corrosion resistant substrate may be used in any other desired application.

Description of the preferred embodiment

Description 1 is a method of making a corrosion resistant substrate, the method comprising: producing a pretreatment film on a surface of a metal substrate to provide a pretreated metal substrate; and heating the pretreated metal substrate at a first temperature to provide the corrosion resistant substrate, wherein the first temperature is greater than 300 ℃; and wherein the metal substrate and/or the pretreated metal substrate is in an F temper, a T4 temper, or a T6 temper.

Statement 2 is the method of any preceding or subsequent statement, wherein the metal substrate comprises an aluminum alloy.

Description 3 is the method of any preceding or subsequent description, wherein the metal substrate comprises a 5xxx series aluminum alloy, a 6xxx series aluminum alloy, or a 7xxx series aluminum alloy.

Description 4 is the method of any preceding or subsequent description, wherein the corrosion resistant substrate is in a T6 temper.

Description 5 is the method of any preceding or subsequent description, wherein the pre-treatment film includes an oxide layer.

Description 6 is the method of any preceding or subsequent description, wherein the oxide layer comprises aluminum oxide, silicon oxide, titanium oxide, chromium oxide, manganese oxide, nickel oxide, yttrium oxide, zirconium oxide, molybdenum oxide, or a combination thereof.

Description 7 is the method of any preceding or subsequent description, wherein creating the pretreatment film comprises applying an inorganic pretreatment composition to a surface of the metal substrate.

Description 8 is the method of any preceding or subsequent description, wherein creating the pre-treatment film comprises anodizing a surface of the metal substrate.

Description 9 is the method of any preceding or subsequent description, wherein creating the pre-treatment film comprises flame hydrolyzing a surface of the metal substrate.

Description 10 is the method of any preceding or subsequent description, wherein the first temperature is 300 ℃ to 550 ℃.

Description 11 is the method of any preceding or subsequent description, wherein the heating comprises heating the pretreated metal substrate at the first temperature for less than 30 minutes.

Description 12 is the method of any preceding or subsequent description, wherein the heating further comprises heating the pretreated metal substrate at a second temperature.

Description 13 is the method of any preceding or subsequent description, wherein the second temperature is lower than the first temperature.

Description 14 is the method of any preceding or subsequent description, wherein the second temperature is 75 ℃ to 250 ℃.

Description 15 is the method of any preceding or subsequent description, wherein the heating comprises heating the pretreated metal substrate at the second temperature for 1 hour to 48 hours.

Description 16 is the method of any preceding or subsequent description, wherein the metal substrate is a continuous coil.

Description 17 is a corrosion resistant coil material comprising: an aluminum alloy continuous coil, wherein a surface of the aluminum alloy continuous coil comprises an inorganic pretreatment film, and wherein the aluminum alloy continuous coil is in an F temper, a T4 temper, or a T6 temper.

Description 18 is the method of any preceding or subsequent description, wherein the continuous coil of aluminum alloy comprises a 5xxx series aluminum alloy, a 6xxx series aluminum alloy, or a 7xxx series aluminum alloy.

Description 19 is the corrosion resistant coil of any preceding or subsequent description, wherein the inorganic pre-treatment film includes an oxide layer.

Description 20 is the corrosion resistant coil of any preceding or subsequent description, wherein the oxide layer comprises aluminum oxide, silicon oxide, titanium oxide, chromium oxide, manganese oxide, nickel oxide, yttrium oxide, zirconium oxide, molybdenum oxide, or a combination thereof.

Description 21 is a method of making a corrosion resistant substrate, the method comprising producing a pretreatment film on a surface of a metal substrate to provide a pretreated metal substrate; and heating the pretreated metal substrate at a first temperature to provide the corrosion resistant substrate, wherein the metal substrate and/or the pretreated metal substrate is in an F temper, and wherein the corrosion resistant substrate is in a T5 temper, a T6 temper, a T61 temper, a T7 temper, a T8x temper, or a T9 temper.

Examples

The following examples are intended to further illustrate the invention without, however, limiting it in any way. On the contrary, it is to be clearly understood that resort may be had to various embodiments, modifications, and equivalents thereof which, after reading the description herein, may suggest themselves to those skilled in the art without departing from the spirit of the present invention.

Example 1: adhesion durability test

As noted above, the thermal modification process described herein produces corrosion resistant substrates that exhibit excellent adhesion durability. This example serves to illustrate the improvement in adhesion durability of corrosion resistant substrates produced according to the methods described herein relative to metal substrates pretreated according to conventional methods and not thermally modified.

Several samples of corrosion resistant substrates were prepared using AA7075 aluminum alloy according to the disclosed method to test the properties of the corrosion resistant substrates. Each of the samples tested is shown in table 1. Samples were prepared with different pretreatment methods and contained different components as indicated in table 1. In addition, the samples were prepared with different tempers, as indicated in table 1. Each sample was thermally modified as follows: each sample was heated at 485 deg.C for 5 minutes followed by 125 deg.C for 24 hours. After this thermal modification, each sample was in a T6 temper.

Several comparative samples (comparative 1-7) were also prepared and tested as shown in table 1. A comparative sample was prepared by creating a pre-treated membrane. These samples were not thermally modified.

TABLE 1

The adhesion durability test was performed on the above samples and the comparative articles. In this test, a set of six lap joints (joints)/joints (bonds) per sample was bolted in series and placed vertically in a 90% Relative Humidity (RH) humidity cabinet. The temperature was maintained at 50 ℃. A force load of 2.4kN was applied to the joint sequence. The adhesion durability test is a cyclic exposure test conducted for up to 60 cycles. Each cycle lasted 24 hours. In each cycle, the joints were exposed in a humidity cabinet for 22 hours, then soaked in 5% NaCl for 15 minutes and finally air dried for 105 minutes. At the time of four joint breaks, testing of the particular set of joints was stopped and indicated as adhesive failure. For the present disclosure, completion of 45 cycles without adhesive failure indicates that the assembled header passed the adhesion durability test. After 60 cycles were completed, the test was stopped.

The adhesion durability test results are shown in table 2 below. In table 2, each joint is numbered 1 to 6, with joint 1 being the top joint and joint 6 being the bottom joint when oriented vertically. Unless otherwise noted, the numbers in the cells indicate the number of successful cycles before rupture. The asterisk (") next to the number indicates that the joint was not damaged, but the test was stopped. The results are summarized in table 2 below:

TABLE 2

The exemplary corrosion resistant substrates thermally modified according to the present disclosure exhibited excellent adhesion durability, with all but three samples (sample 5, sample 12, and sample 13) passing the test. Notably, two of the three samples that failed the durability test included an organic pre-treatment film. The comparative substrates exhibited relatively poor adhesion durability, and each failed the durability test.

Example 2: adhesion durability test

This example further illustrates the improvement in adhesion durability of the corrosion resistant substrates produced according to the methods described herein relative to metal substrates pretreated according to conventional methods and not thermally modified.

Several samples of corrosion resistant substrates were prepared using AA7075 aluminum alloy according to the disclosed method to test the properties of the corrosion resistant substrates. Each of the samples tested is shown in table 3. The samples were prepared by etching with acid and applying a different titanium/zirconium pretreatment (Gardobond 4591 from Chemetall GmbH (frankfurt, germany)), as specified in table 3. Each sample was prepared at an initial F temper. Each sample was thermally modified to adjust for tempering as indicated in table 3.

TABLE 3

The above samples were subjected to adhesion durability tests. In this test, a set of six lap joints/joints per sample were bolted in series and placed vertically in a 90% Relative Humidity (RH) humidity cabinet. The temperature was maintained at 50 ℃. A force load of 2.4kN was applied to the sequence of joints. The adhesion durability test is a cyclic exposure test conducted for up to 60 cycles. Each cycle lasted 24 hours. In each cycle, the joints were exposed in a humidity cabinet for 22 hours, then soaked in 5% NaCl for 15 minutes, and finally air-dried for 105 minutes. At the time of four joint breaks, testing of the particular set of joints was stopped and indicated as adhesive failure. For the present disclosure, completion of 45 cycles without adhesive failure indicates that the gang head passed the adhesive durability test. After 60 cycles were completed, the test was stopped.

The adhesion durability test results are shown in table 4 below. In table 4, each joint is numbered 1 to 6, with joint 1 being the top joint and joint 6 being the bottom joint when oriented vertically. Unless otherwise noted, the numbers in the cells indicate the number of successful cycles before rupture. The asterisk (") next to the number indicates that the joint was not damaged, but the test was stopped. The results are summarized in table 4 below:

TABLE 4

The exemplary corrosion resistant substrates thermally modified according to the present disclosure exhibited excellent adhesion durability, with all but one sample (sample 17) passing the test.

Example 3: GDOES Depth Profiling (Depth Profiling)

Several samples of corrosion resistant substrates were prepared using AA7075 aluminum alloy according to the disclosed method to test the properties of the corrosion resistant substrates. Each of the samples tested is shown in table 5. The samples were prepared by etching with acid and applying different titanium/zirconium pretreatments (Gardobond 4591 from Chemetall GmbH (frankfurt, germany)) as specified in table 5. Each sample was prepared at an initial F temper. Each sample was thermally modified to adjust for tempering as indicated in table 5.

TABLE 3

For the analysis of the surface and depth profile (depth profile), glow discharge emission spectroscopy (GDOES) was performed on each sample. GDOES gave a quantitative depth distribution of elements in the surface film of each sample. The results of the GDOES depth profiling are shown in fig. 1, which shows the enrichment of copper and silicon on the surface of the sample. With respect to copper, samples 25 and 26 exhibited similar profiles after 12 seconds of sputtering, where there was copper enrichment. With respect to silicon, sample 25 has a higher but thinner silicon enrichment than sample 26, which is likely due to the difference in acid etching between the two samples.

Claims (21)

1. A method of making a corrosion resistant substrate, the method comprising:

producing a pretreatment film on a surface of a metal substrate to provide a pretreated metal substrate; and

heating the pretreated metal substrate at a first temperature to provide the corrosion resistant substrate,

wherein the first temperature is greater than 300 ℃, and

wherein the metal substrate and/or the pretreated metal substrate is in an F temper, a T4 temper, or a T6 temper.

2. The method of claim 1, wherein the metal substrate comprises an aluminum alloy.

3. The method of claim 2, wherein the metal substrate comprises a 5xxx series aluminum alloy, a 6xxx series aluminum alloy, or a 7xxx series aluminum alloy.

4. The method of claim 1, wherein the corrosion resistant substrate is in a T6 temper.

5. The method of claim 1, wherein the pre-treatment film comprises an oxide layer.

6. The method of claim 5, wherein the oxide layer comprises aluminum oxide, silicon oxide, titanium oxide, chromium oxide, manganese oxide, nickel oxide, yttrium oxide, zirconium oxide, molybdenum oxide, or a combination thereof.

7. The method of claim 1, wherein creating the pretreatment film comprises applying an inorganic pretreatment composition to the surface of the metal substrate.

8. The method of claim 1, wherein creating the pre-treatment film comprises anodizing the surface of the metal substrate.

9. The method of claim 1, wherein producing the pretreatment film comprises flame hydrolyzing the surface of the metal substrate.

10. The method of claim 1, wherein the first temperature is 300 ℃ to 550 ℃.

11. The method of claim 1, wherein the heating comprises heating the pretreated metal substrate at the first temperature for less than 30 minutes.

12. The method of claim 1, wherein the heating further comprises heating the pretreated metal substrate at a second temperature.

13. The method of claim 12, wherein the second temperature is lower than the first temperature.

14. The method of claim 12, wherein the second temperature is 75 ℃ to 250 ℃.

15. The method of claim 12, wherein the heating comprises heating the pretreated metal substrate at the second temperature for 1 hour to 48 hours.

16. The method of claim 1, wherein the metal substrate is a continuous coil.

17. A corrosion resistant coil, comprising:

an aluminum alloy continuous coil, wherein a surface of the aluminum alloy continuous coil includes an inorganic pretreatment film, and

wherein the aluminum alloy continuous coil is in an F temper, a T4 temper, or a T6 temper.

18. The method of claim 17, wherein the continuous coil of aluminum alloy comprises a 5xxx series aluminum alloy, a 6xxx series aluminum alloy, or a 7xxx series aluminum alloy.

19. The corrosion resistant coil as set forth in claim 17 wherein said inorganic pretreatment film includes an oxide layer.

20. The corrosion resistant coil of claim 19, wherein the oxide layer comprises aluminum oxide, silicon oxide, titanium oxide, chromium oxide, manganese oxide, nickel oxide, yttrium oxide, zirconium oxide, molybdenum oxide, or combinations thereof.

21. A method of making a corrosion resistant substrate, the method comprising:

producing a pretreatment film on a surface of a metal substrate to provide a pretreated metal substrate; and

heating the pretreated metal substrate at a first temperature to provide the corrosion resistant substrate,

wherein the metal substrate and/or the pretreated metal substrate is in an F temper, and

wherein the corrosion resistant substrate is in a T5 temper, a T6 temper, a T61 temper, a T7 temper, a T8x temper, or a T9 temper.

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