Patent Application
20230313353
The present disclosure relates to metallurgy generally and more specifically to aluminum alloy products and methods for making aluminum alloy products having improved intergranular and stress corrosion cracking resistance.
High strength aluminum alloys are desirable for use in a variety of applications, such as the automotive and aerospace industries. Exemplary high strength aluminum alloys include 7xxx series aluminum alloys. During the processing of a 7xxx series aluminum alloy, the alloy may undergo heat treatment followed by rapid quenching to lock in solutionized alloying elements and provide for suitable intergranular and stress corrosion cracking resistance and desirable mechanical properties. If quenching does not take place on a suitable time scale, the resultant product may be susceptible to intergranular and stress corrosion cracking and/or have unsuitable mechanical properties.
The fast quench rates required for 7xxx series aluminum alloy processing leave extremely small operating windows between the hot treatment step and the quenching step. Such a small window means that a product made from a 7xxx series aluminum alloy may need to be immediately quenched after the hot processing step, leaving little to no time for other processing steps such as hot forming or transferring the hot product between locations. Fast quench rates may also be undesirable because they often employ specialized equipment and increase processing complexity.
The term embodiment and like terms are intended to refer broadly to all of the subject matter of this disclosure and the claims below. Statements containing these terms should be understood not to limit the subject matter described herein or to limit the meaning or scope of the claims below. Embodiments of the present disclosure covered herein are defined by the claims below, not this summary. This summary is a high-level overview of various aspects of the disclosure and introduces some of the concepts that are further described in the Detailed Description section below. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used in isolation to determine the scope of the claimed subject matter. The subject matter should be understood by reference to appropriate portions of the entire specification of this disclosure, any or all drawings and each claim.
Described herein are rolled aluminum alloy products and methods of making aluminum alloy products having quench insensitivity and improved strength values. In an aspect, described are methods of making aluminum alloy products. The methods may include heating a rolled aluminum alloy product. The rolled aluminum alloy product may include a 7xxx series aluminum alloy product having from 4.00 wt. % to 15.00 wt. % Zn, from 0.10 wt. % to 3.50 wt. % Cu, from 1.00 wt. % to 4.00 wt. % Mg, from 0.05 wt. % to 0.50 wt. % Fe, from 0.05 wt. % to 0.30 wt. % Si, from 0.05 wt. % to 0.25 wt. % Zr, up to 0.25 wt. % Mn, up to 0.20 wt. % Cr, up to 0.15 wt. % Ti, and Al. In some embodiments, the rolled aluminum alloy product may have from 4.00 wt. % to 15.00 wt. % Zn, from 0.20 wt. % to 2.60 wt. % Cu, from 1.40 wt. % to 2.80 wt. % Mg, from 0.10 wt. % to 0.35 wt. % Fe, from 0.05 wt. % to 0.20 wt. % Si, from 0.05 wt. % to 0.15 wt. % Zr, from 0.01 wt. % to 0.05 wt. % Mn, from 0.01 wt. % to 0.05 wt. % Cr, from 0.001 wt. % to 0.05 wt. % Ti, and Al. While in other embodiments, the rolled aluminum alloy product may have from 4.00 wt. % to 15.00 wt. % Zn, from 0.30 wt. % to 2.50 wt. % Cu, from 1.60 wt. % to 2.60 wt. % Mg, from 0.10 wt. % to 0.25 wt. % Fe, from 0.07 wt. % to 0.15 wt. % Si, from 0.09 wt. % to 0.15 wt. % Zr, from 0.02 wt. % to 0.05 wt. % Mn, from 0.03 wt. % to 0.05 wt. % Cr, from 0.003 wt. % to 0.035 wt. % Ti, and Al. While in still other embodiments, the rolled aluminum alloy product may have from 4.00 wt. % to 15.00 wt. % Zn, from 0.20 wt. % to 2.10 wt. % Cu, from 2.20 wt. % to 2.40 wt. % Mg, from 0.18 wt. % to 0.23 wt. % Fe, from 0.09 wt. % to 0.12 wt. % Si, from 0.05 wt. % to 0.15 wt. % Zr, from 0.04 wt. % to 0.09 wt. % Mn, from 0.03 wt. % to 0.09 wt. % Cr, from 0.01 wt. % to 0.02 wt. % Ti, up to 0.15 wt. % of impurities, and Al. Optionally, the rolled aluminum alloy product may further include up to 0.20 wt. % of one or more of Mo, Nb, Be, B, Co, Sn, Sr, V, In, Hf, Ag, Sc and Ni.
The methods described herein may include heating the rolled aluminum alloy product to a first temperature of from 400° C. to 525° C. For example, the first temperature may be from 450° C. to 510° C. In some embodiments, the first temperature may be a solutionizing temperature. After heating the rolled aluminum alloy product to the first temperature, the rolled aluminum alloy product may be maintained at the first temperature or within 10° C. of the first temperature for a time duration of from 15 seconds to 30 minutes. The method may also include quenching the rolled aluminum alloy product at a quench rate from 0.5° C./s to 125° C./s to generate a heat-treated aluminum alloy product. In some embodiments, the quench rate may be from 5° C./s to 125° C./s, while in other embodiments, the quench rate may be from 10° C./s to 125° C./s. Optionally, the quench rate may be from 5° C./s to 10° C./s, from 10° C./s to 15° C./s, from 15° C./s to 20° C./s, from 20° C./s to 25° C./s, from 25° C./s to 30° C./s, from 30° C./s to 35° C./s, from 35° C./s to 40° C./s, from 40° C./s to 45° C./s, from 45° C./s to 50° C./s, from 50° C./s to 55° C./s, from 55° C./s to 60° C./s, from 60° C./s to 65° C./s, from 65° C./s to 70° C./s, from 70° C./s to 75° C./s, from 75° C./s to 80° C./s, from 80° C./s to 85° C./s, from 85° C./s to 90° C./s, from 90° C./s to 95° C./s, from 95° C./s to 100° C./s, from 100° C./s to 105° C./s, from 105° C./s to 110° C./s, from 110° C./s to 115° C./s, from 115° C./s to 120° C./s, or from 120° C./s to 125° C./s.
In some embodiments, quenching the rolled aluminum alloy product may include a first quenching at a first quench rate to an intermediate temperature and a second quenching at a second quench rate to the second temperature. The second quench rate may be greater than the first quench rate. The rolled aluminum alloy product may be quenched until the rolled aluminum alloy product reaches a second temperature of from 10° C. to 100° C. Optionally, the second temperature may be an ambient temperature. In some embodiments, quenching the rolled aluminum alloy product may include a die quenching process, a water quenching process, and/or a forced air quenching process. As an example, the first quench rate may correspond to or occur when the aluminum alloy product is removed from the heating system but before the product is introduced to the quenching system (e.g., a die quench). The initial drop in temperature due to exposure to ambient conditions may be or correspond to the first quench rate. Optionally, the second quenching may then correspond to the quenching that occurs during an active quenching process, such as a die quenching process.
Heating and quenching the rolled aluminum alloy product may correspond to a solutionizing heat treatment process, in some embodiments. Optionally, the method may further include subjecting the rolled aluminum alloy product to a hot forming process after heating the rolled aluminum alloy product. In some cases, the method may also include aging the heat-treated aluminum alloy product, such as in a T6 temper or T7 temper. For example, the heat-treated aluminum alloy product may optionally be further heated to a temperature from 100° C. to 170° C. and maintained at the temperature for 12 hours to 30 hours. Other aging and tempering processes, practices, and conditions may be utilized, such as those described in U.S. Patent Application publication US 2018/0202031, which is hereby incorporated by reference.
The heat-treated aluminum alloy product may exhibit desirable and/or improved mechanical properties. For example, the heat-treated aluminum alloy product generated by quenching the rolled aluminum alloy product may exhibit a strain ratio of from 0.30 to 0.80. For example, the heat-treated aluminum alloy product may exhibit a strain ratio of from 0.375 to 0.425 when the quench rate is about or less than 125° C./s. In some embodiments, the quench rate may be greater than 125° C. The strain ratio may be determined according to an ASTM G129 standard test method, such as ASTM G129-00(2013), Standard Practice for Slow Strain Rate Testing to Evaluate the Susceptibility of Metallic Materials to Environmentally Assisted Cracking, ASTM International, West Conshohocken, PA, 2013, which is hereby incorporated by reference, or according to an ASTM G139 standard test method, such as ASTM G139-05(2015), Standard Test Method for Determining Stress-Corrosion Cracking Resistance of Heat-Treatable Aluminum Alloy Products Using Breaking Load Method, ASTM International, West Conshohocken, PA, 2015, which is hereby incorporated by reference. In some embodiments, the heat-treated aluminum alloy product may exhibit an ultimate tensile strength of from 500 MPa to 650 MPa. For example, the heat-treated aluminum alloy product may exhibit an ultimate tensile strength of from 605 MPa to 615 MPa when the quench rate is about or less than 125° C./s. In some embodiments, the heat-treated aluminum alloy product may exhibit a yield strength of from 400 MPa to 600 MPa. For example, the heat-treated aluminum alloy product may exhibit a yield strength of from 560 MPa to 580 MPa when the quench rate is about or less than 125° C./s. In some embodiments, the heat-treated aluminum alloy product may exhibit a uniform elongation of from 7.50% to 10.50%. For example, the heat-treated aluminum alloy product may exhibit a uniform elongation of from 9.00% to 9.60% when the quench rate is about or less than 125° C./s. In some embodiments, the heat-treated aluminum alloy product may exhibit a total elongation of from 10.00% to 15.00%. For example, the heat-treated aluminum alloy product may exhibit a total elongation of from 13.80% to 14.20% when the quench rate is about or less than 125° C./s. In some embodiments, the heat-treated aluminum alloy product may exhibit precipitate-free zone widths from 10 nm to 110 nm. For example, the heat-treated aluminum alloy product may exhibit precipitate-free zone widths from 10 nm to 13 nm when the quench rate is about or less than 125° C./s.
The heat-treated aluminum alloy product may also exhibit superior corrosion resistance. The heat-treated aluminum alloy product generated by quenching may exhibit a corrosion depth of from 5 μm to 300 μm as determined according to an ASTM G110 standard test method. For example, the heat-treated aluminum alloy product may exhibit a corrosion depth from 5 μm to 150 μm or from 25 μm to 50 μm when the quench rate is about 125° C./s. In some cases, the corrosion depth may include at least one of pitting corrosion or intergranular corrosion. In some embodiments, the corrosion may include intergranular corrosion when the quench rate is about 50° C./s or less. Optionally, the corrosion may not include intergranular corrosion when the quench rate is greater than or about 5° C./s.
Optionally, the mechanical properties and corrosion resistance of the heat-treated aluminum alloy products may exceed those stated above when subjected to faster quenching, but it will be appreciated that quenching at rates of less than or about 125° C./s may allow for more flexibility in handling and processing the hot aluminum alloy product immediately after heat-treatment without the final heat-treated aluminum alloy product suffering from poor mechanical properties or corrosion resistance. In this way, by using the aluminum alloy products described herein, the quenching process may be less complex and more forgiving and may simplify heat-treatment, quenching, stamping, or other processes.
In other aspects, a product may be described herein, such as a heat-treated aluminum alloy product. The heat-treated aluminum alloy product may include a 7xxx series aluminum alloy product having from 4.00 wt. % to 15.00 wt. % Zn, from 0.10 wt. % to 3.50 wt. % Cu, from 1.00 wt. % to 4.00 wt. % Mg, from 0.05 wt. % to 0.50 wt. % Fe, from 0.05 wt. % to 0.30 wt. % Si, from 0.05 wt. % to 0.25 wt. % Zr, up to 0.25 wt. % Mn, up to 0.20 wt. % Cr, up to 0.15 wt. % Ti, and Al. In some embodiments, the heat-treated aluminum alloy product may be a formed aluminum alloy product, a hot formed aluminum alloy product, and/or in a T6 temper or T7 temper.
The product may be a heat-treated aluminum alloy product having improved mechanical properties. For example, the heat-treated aluminum alloy product may exhibit a strain ratio of from 0.30 to 0.80. For example, the heat-treated aluminum alloy product may exhibit a strain ratio of from 0.375 to 0.425 when a quench rate is less than or about 125° C./s. The strain ratio may be determined according to an ASTM G129 and/or ASTM G139 standard test method. In some embodiments, the heat-treated aluminum alloy product may exhibit an ultimate tensile strength of from 500 MPa to 650 MPa, such as from 500 MPa to 510 MPa, 510 MPa to 520 MPa, 520 MPa to 530 MPa, 530 MPa to 540 MPa, 540 MPa to 550 MPa, 550 MPa to 560 MPa, 560 MPa to 570 MPa, 570 MPa to 580 MPa, 580 MPa to 590 MPa, 590 MPa to 600 MPa, 600 MPa to 610 MPa, 610 MPa to 620 MPa, 620 MPa to 630 MPa, 630 MPa to 640 MPa, or 640 MPa to 650 MPa. For example, the heat-treated aluminum alloy product may exhibit an ultimate tensile strength of from 605 MPa to 615 MPa when a quench rate is less than or about 125° C./s. In some embodiments, the heat-treated aluminum alloy product may exhibit a yield strength of from 400 MPa to 600 MPa, such as from 400 MPa to 410 MPa, 410 MPa to 420 MPa, 420 MPa to 430 MPa, 430 MPa to 440 MPa, 440 MPa to 450 MPa, 450 MPa to 460 MPa, 460 MPa to 470 MPa, 470 MPa to 480 MPa, 480 MPa to 490 MPa, 490 MPa to 500 MPa, 500 MPa to 510 MPa, 510 MPa to 520 MPa, 520 MPa to 530 MPa, 530 MPa to 540 MPa, 540 MPa to 550 MPa, 550 MPa to 560 MPa, 560 MPa to 570 MPa, 570 MPa to 580 MPa, 580 MPa to 590 MPa, or 590 MPa to 600 MPa. For example, the heat-treated aluminum alloy product may exhibit a yield strength of from 560 MPa to 580 MPa when a quench rate is less than or about 125° C./s. In some embodiments, the heat-treated aluminum alloy product may exhibit a uniform elongation of from 7.50% to 10.50%, such as from 7.50% to 8.00%, from 8.00% to 8.50%, from 8.50% to 9.00%, from 9.00% to 9.50%, from 9.50% to 10.00%, or from 10.00% to 10.50%. For example, the heat-treated aluminum alloy product may exhibit a uniform elongation of from 9.00% to 9.60% when a quench rate is less than or about 125° C./s. In some embodiments, the heat-treated aluminum alloy product may exhibit a total elongation of from 10.00% to 15.00%, such as from 10.00% to 10.50%, from 10.50% to 11.00%, from 11.00% to 11.50%, from 11.50% to 12.00%, from 12.00% to 12.50%, from 12.50% to 13.00%, from 13.00% to 13.50%, from 13.50% to 14.00%, from 14.00% to 14.50%, or from 14.50% to 15.00%. For example, the heat-treated aluminum alloy product may exhibit a total elongation of from 13.80% to 14.20% when a quench rate is less than or about 125° C./s. In some embodiments, the heat-treated aluminum alloy product may exhibit precipitate-free zone widths from 10 nm to 110 nm, such as from 10 nm to 11 nm, from 11 nm to 12 nm, from 12 nm to 13 nm, from 13 nm to 14 nm, from 14 nm to 15 nm, from 15 nm to 20 nm, from 20 nm to 25 nm, from 25 nm to 30 nm, from 30 nm to 35 nm, from 35 nm to 40 nm, from 40 nm to 45 nm, from 45 nm to 50 nm, from 50 nm to 55 nm, from 55 nm to 60 nm, from 60 nm to 65 nm, from 65 nm to 70 nm, from 70 nm to 75 nm, from 75 nm to 80 nm, from 80 nm to 85 nm, from 85 nm to 90 nm, from 90 nm to 95 nm, from 95 nm to 100 nm, from 100 nm to 105 nm, or from 105 nm to 110 nm. For example, the heat-treated aluminum alloy product may exhibit precipitate-free zone widths from 10 nm to 13 nm when a quench rate is less than or about 125° C./s.
The product may include a heat-treated aluminum alloy product having superior corrosion resistance. For example, the heat-treated aluminum alloy product may exhibit a corrosion depth of from 5 μm to 300 μm as determined according to an ASTM G110 standard test method, such as from 5 μm to 10 μm, from 10 μm to 15 μm, from 15 μm to 20 μm, from 20 μm to 25 μm, from 25 μm to 30 μm, from 30 μm to 35 μm, from 35 μm to 40 μm, from 40 μm to 45 μm, from 45 μm to 50 μm, from 50 μm to 60 μm, from 60 μm to 70 μm, from 70 μm to 80 μm, from 80 μm to 90 μm, from 90 μm to 100 μm, from 100 μm to 110 μm, from 110 μm to 120 μm, from 120 μm to 130 μm, from 130 μm to 140 μm, from 140 μm to 150 μm, from 150 μm to 160 μm, from 160 μm to 170 μm, from 170 μm to 180 μm, from 180 μm to 190 μm, from 190 μm to 200 μm, from 200 μm to 210 μm, from 210 μm to 220 μm, from 220 μm to 230 μm, from 230 μm to 240 μm, from 240 μm to 250 μm, from 250 μm to 260 μm, from 260 μm to 270 μm, from 270 μm to 280 μm, from 280 μm to 290 μm, or from 290 μm to 300 μm. In some embodiments, the heat-treated aluminum alloy product may exhibit a corrosion depth from 5 μm to 150 μm or from 25 μm to 50 μm when a quench rate is less than or 125° C./s.
In some embodiments, the heat-treated aluminum alloy product may be generated by heating a rolled aluminum alloy product to a first temperature. The rolled aluminum alloy product may include a 7xxx series aluminum alloy. The rolled aluminum alloy product may be heated to a temperature from 400° C. to 525° C. The rolled aluminum alloy product may be maintained at the first temperature or within 10° C. of the first temperature for a time duration of from 15 seconds to 30 minutes, such as from 15 seconds to 30 seconds, from 30 seconds to 1 minute, from 1 minute to 5 minutes, from 5 minutes to 10 minutes, from 10 minutes to 15 minutes, from 15 minutes to 20 minutes, from 20 minutes to 25 minutes, or from 25 minutes to 30 minutes. The rolled aluminum alloy product may also be quenched at a quench rate from 0.5° C./s to 125° C./s, such as from 0.5° C./s to 1° C./s, from 1° C./s to 5° C./s, from 5° C./s to 10° C./s, from 10° C./s to 25° C./s, from 25° C./s to 50° C./s, from 50° C./s to 75° C./s, from 75° C./s to 100° C./s, or from 100° C./s to 125° C./s. Optionally, the product may be generated by any of the methods described herein.
Automotive and aerospace products are also described herein. In some embodiments, an automotive product may incorporate a product as described herein. For example, the automotive product may incorporate a heat-treated aluminum alloy product as described above. In other embodiments, an aerospace product may incorporate a product as described herein. For example, the aerospace product may incorporate a heat-treated aluminum alloy product as described above. Optionally, an automotive product may incorporate a product generated according to any of the methods described herein. For example, the automotive product may incorporate a heat-treated aluminum alloy product generated by any of the methods described above. Similarly, an aerospace product may incorporate a product generated according to any of the methods described herein. For example, the aerospace product may incorporate a heat-treated aluminum alloy product generated by any of the methods described above.
Other objects and advantages will be apparent from the following detailed description of non-limiting examples.
The specification makes reference to the following appended figures, in which use of like reference numerals in different figures is intended to illustrate like or analogous components.
Described herein are aluminum alloy products and methods of making aluminum alloy products processed in a way that achieves improved quench sensitivity. Quench sensitivity commonly refers to the impact of quenching on a metal product's properties, such as mechanical properties and corrosion resistance. Quenching refers to a rapid cooling of a metal product from a first temperature, such as a heat treatment temperature, to a lower temperature, such as room temperature. For example, during processing, aluminum alloy products may undergo a heat treatment in which the aluminum alloy product is heated to a first high temperature, such as from 450° C. to 600° C. The aluminum alloy products may be subjected to heat treatments, such as those described in U.S. patent application Ser. No. 15/336,982, which is herein incorporated in its entirety by reference. One objective of quenching is to preserve a metastable solid solution formed by the heat treatment. When a product is cooled at a sufficient rate from the first temperature to a second temperature, often near or at room temperature, a solid solution in which solutes remain in the alloy solution may be achieved. Solute retention may be desirable because precipitation of the solute out of solution during quenching can lead to localized overaging, loss of grain-boundary corrosion resistance, and, importantly, poor response to age hardening treatments. Retention of the solute in the solid solution may allow for solute atoms to be available to form zones of homogenous precipitation which are important for strengthening the metal product during age hardening treatments. Another goal of quenching may be to maintain a desirable number of vacant lattice sites to assist in promoting low-temperature diffusion during the aging stage of precipitation hardening.
Some metal products, such as aluminum alloy products, may be particularly sensitive to solute loss. Particularly during age hardening treatments, solute loss may affect the resulting properties of an aluminum alloy product. Solute loss refers to the solutes that are chemically bonded with other elements, rendering them unavailable for precipitation hardening. When quench rates are not sufficiently rapid, then solute atoms are prone to diffuse to the grain boundaries, as well as the vacancies that migrate to disordered regions. Such movement of solute atoms is often irretrievable and may permanently affect the properties of the metal product. For example, some metal products that are not quenched at a sufficient rate may exhibit higher rates of intergranular corrosion and stress cracking corrosion, and have reduced yield strength, tensile strength, and grain elongation. Accordingly, the most desirable mechanical properties attainable may be generally associated with high quench rates.
However, achieving high quench rates may be costly, complex, or require time-sensitive processes which minimize opportunity for additional processing between heat treatment steps and quenching steps. Moreover, high quench rates may undesirably affect a metal product's properties. High quench rates may also result in distortion and development of residual stress within the microstructure of the product, in some cases. Aluminum alloy products may be prone to distortion during quenching due to aluminum's high linear expansion coefficient, for example. The coefficient of linear expansion of aluminum is twice that of steel and thus, during large temperature swings, significant amounts of strain can develop due to thermal expansion or contraction. Accordingly, a balance between a quench rate that sufficiently retains most of the hardening elements and compounds in solution and minimizes distortion and residual stress may be desirable to make an aluminum alloy product having optimal properties.
One approach to balancing the effects of quenching involves multi-step aging processes. Often these multi-step aging processes include at least one rapid quench step. For example, the initial quench from the first temperature may be rapid to maintain the solid solution. However, multi-step aging processes may be complex, costly, and time consuming. Accordingly, as described herein, methods and metal products are provided for achieving desirable properties using only a single step aging process, despite use of smaller quench rates. Additionally, the disclosed methods and metal products may exhibit quench insensitivity, resulting in improved mechanical properties, such as improved strength values, even at low quench rates.
In particular, the disclosed methods and techniques may provide for quench-insensitive 7xxx series aluminum alloys and products subjected to only a single step aging process. The quench-insensitive 7xxx series aluminum alloys described herein may have improved intergranular corrosion and stress corrosion cracking resistance without rapid quenching. Exemplary 7xxx series aluminum alloys for use in the disclosed methods and techniques are described in U.S. patent application Ser. No. 15/336,982, which is hereby incorporated herein by reference.
As used herein, the terms “invention,” “the invention,” “this invention” and “the present invention” are intended to refer broadly to all of the subject matter of this patent application and the claims below. Statements containing these terms should be understood not to limit the subject matter described herein or to limit the meaning or scope of the patent claims below.
In this description, reference is made to alloys identified by AA numbers and other related designations, such as “series” or “7xxx.” For an understanding of the number designation system most commonly used in naming and identifying aluminum and its alloys, see “International Alloy Designations and Chemical Composition Limits for Wrought Aluminum and Wrought Aluminum Alloys” or “Registration Record of Aluminum Association Alloy Designations and Chemical Compositions Limits for Aluminum Alloys in the Form of Castings and Ingot,” both published by The Aluminum Association.
As used herein, a plate generally has a thickness of greater than about 15 mm. For example, a plate may refer to an aluminum product having a thickness of greater than about 15 mm, greater than about 20 mm, greater than about 25 mm, greater than about 30 mm, greater than about 35 mm, greater than about 40 mm, greater than about 45 mm, greater than about 50 mm, or greater than about 100 mm.
As used herein, a shate (also referred to as a sheet plate) generally has a thickness of from about 4 mm to about 15 mm. For example, a shate may have a thickness of about 4 mm, about 5 mm, about 6 mm, about 7 mm, about 8 mm, about 9 mm, about 10 mm, about 11 mm, about 12 mm, about 13 mm, about 14 mm, or about 15 mm.
As used herein, a sheet generally refers to an aluminum product having a thickness of less than about 4 mm. For example, a sheet may have a thickness of less than about 4 mm, less than about 3 mm, less than about 2 mm, less than about 1 mm, less than about 0.5 mm, or less than about 0.3 mm (e.g., about 0.2 mm).
Reference may be made in this application to alloy temper or condition. For an understanding of the alloy temper descriptions most commonly used, see “American National Standards (ANSI) H35 on Alloy and Temper Designation Systems.” An F condition or temper refers to an aluminum alloy as fabricated. An O condition or temper refers to an aluminum alloy after annealing. An Hxx condition or temper, also referred to herein as an H temper, refers to a non-heat treatable aluminum alloy after cold rolling with or without thermal treatment (e.g., annealing). Suitable H tempers include HX1, HX2, HX3 HX4, HX5, HX6, HX7, HX8, or HX9 tempers. A T1 condition or temper refers to an aluminum alloy cooled from hot working and naturally aged (e.g., at room temperature). A T2 condition or temper refers to an aluminum alloy cooled from hot working, cold worked and naturally aged. A T3 condition or temper refers to an aluminum alloy solution heat treated, cold worked, and naturally aged. A T4 condition or temper refers to an aluminum alloy solution heat treated and naturally aged. A T5 condition or temper refers to an aluminum alloy cooled from hot working and artificially aged (at elevated temperatures). A T6 condition or temper refers to an aluminum alloy solution heat treated and artificially aged. A T7 condition or temper refers to an aluminum alloy solution heat treated and artificially overaged. A T8x condition or temper refers to an aluminum alloy solution heat treated, cold worked, and artificially aged. A T9 condition or temper refers to an aluminum alloy solution heat treated, artificially aged, and cold worked. A W condition or temper refers to an aluminum alloy after solution heat treatment.
As used herein, the meaning of “room temperature” can include a temperature of from about 15° C. to about 30° C., for example about 15° C., about 16° C., about 17° C., about 18° C., about 19° C., about 20° C., about 21° C., about 22° C., about 23° C., about 24° C., about 25° C., about 26° C., about 27° C., about 28° C., about 29° C., or about 30° C. As used herein, the meaning of “ambient conditions” or “ambient environment” can include temperatures of about room temperature, relative humidity of from about 20% to about 100%, and barometric pressure of from about 975 millibar (mbar) to about 1050 mbar. For example, relative humidity can be about 20%, about 21%, about 22%, about 23%, about 24%, about 25%, about 26%, about 27%, about 28%, about 29%, about 30%, about 31%, about 32%, about 33%, about 34%, about 35%, about 36%, about 37%, about 38%, about 39%, about 40%, about 41%, about 42%, about 43%, about 44%, about 45%, about 46%, about 47%, about 48%, about 49%, about 50%, about 51%, about 52%, about 53%, about 54%, about 55%, about 56%, about 57%, about 58%, about 59%, about 60%, about 61%, about 62%, about 63%, about 64%, about 65%, about 66%, about 67%, about 68%, about 69%, about 70%, about 71%, about 72%, about 73%, about 74%, about 75%, about 76%, about 77%, about 78%, about 79%, about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, about 99%, about 100%, or anywhere in between. For example, barometric pressure can be about 975 mbar, about 980 mbar, about 985 mbar, about 990 mbar, about 995 mbar, about 1000 mbar, about 1005 mbar, about 1010 mbar, about 1015 mbar, about 1020 mbar, about 1025 mbar, about 1030 mbar, about 1035 mbar, about 1040 mbar, about 1045 mbar, about 1050 mbar, or anywhere in between.
All ranges disclosed herein are to be understood to encompass any and all subranges subsumed therein. For example, a stated range of “1 to 10” should be considered to include any and all subranges between (and inclusive of) the minimum value of 1 and the maximum value of 10; that is, all subranges beginning with a minimum value of 1 or more, e.g., 1 to 6.1, and ending with a maximum value of 10 or less, e.g., 5.5 to 10. Unless stated otherwise, the expression “up to” when referring to the compositional amount of an element means that element is optional and includes a zero percent composition of that particular element. Unless stated otherwise, all compositional percentages are in weight percent (wt. %).
As used herein, the meaning of “a,” “an,” and “the” includes singular and plural references unless the context clearly dictates otherwise.
In the present description, aluminum alloy products and their components may be described in terms of their elemental composition in weight percent (wt. %). In each alloy, the remainder is aluminum, with a maximum wt. % of 0.15% for the sum of all impurities.
Incidental elements, such as grain refiners and deoxidizers, or other additives may be present in the invention and may add other characteristics on their own without departing from or significantly altering the alloy described herein or the characteristics of the alloy described herein.
For example,
In embodiments, quench sensitivity may be determined based on quench rate and the type of corrosion exhibited by the aluminum alloy product upon corrosion testing. During corrosion testing of quenched products, various types of corrosion may be exhibited. For example, pitting corrosion may be exhibited in which cavities or holes, representing material loss, are formed within the aluminum alloy. In other examples, intergranular corrosion may be exhibited. Intergranular corrosion, also known as intercrystalline corrosion or interdendritic corrosion, may be characterized as a form of localized corrosion in which grain boundaries and material immediately adjacent to the grain boundaries are attacked. In some cases, quench sensitivity may be determined based on the form of corrosion and/or the transition from one form of corrosion to another. For example, quench sensitivity may correspond to a change in corrosion morphology, such as a switch from pitting corrosion to intergranular corrosion when a product is subjected to various quench rates. In some cases, the slower an aluminum alloy product may be quenched without exhibiting intergranular corrosion in a corrosion test, the more quench-insensitive the aluminum alloy product may be. Intergranular corrosion may be more undesirable than pitting corrosion because of the ability of intergranular corrosion to more easily propagate cracks under stress conditions.
As illustrated in
In some examples, the aluminum alloy may have an elemental composition as provided in Table 2.
In some examples, the aluminum alloy may have an elemental composition as provided in Table 3.
In some examples, the aluminum alloy may have an elemental composition as provided in Table 4.
In some examples, the alloys described herein may include zinc (Zn) in an amount of from 4.00% to 15.00% (e.g., from 5.40% to 9.50%, from 5.60% to 9.30%, from 5.80% to 9.20%, or from 4.00% to 5.00%) based on the total weight of the alloy. For example, the alloy may include 4.00%, 4.10%, 4.20%, 4.30%, 4.40%, 4.50%, 4.60%, 4.70%, 4.80%, 4.90%, 5.00%, 5.10%, 5.20%, 5.30%, 5.40%, 5.50%, 5.60%, 5.70%, 5.80%, 5.90%, 6.00%, 6.10%, 6.20%, 6.30%, 6.40%, 6.50%, 6.60%, 6.70%, 6.80%, 6.90%, 7.00%, 7.10%, 7.20%, 7.30%, 7.40%, 7.50%, 7.60%, 7.70%, 7.80%, 7.90%, 8.00%, 8.10%, 8.20%, 8.30%, 8.40%, 8.50%, 8.60%, 8.70%, 8.80%, 8.90%, 9.00%, 9.10%, 9.20%, 9.30%, 9.40%, 9.50%, 9.60%, 9.70%, 9.80%, 9.90%, 10.00%, 10.10%, 10.20%, 10.30%, 10.40%, 10.50%, 10.60%, 10.70%, 10.80%, 10.90%, 11.00%, 11.10%, 11.20%, 11.30%, 11.40%, 11.50%, 11.60%, 11.70%, 11.80%, 11.90%, 12.00%, 12.10%, 12.20%, 12.30%, 12.40%, 12.50%, 12.60%, 12.70%, 12.80%, 12.90%, 13.00%, 13.10%, 13.20%, 13.30%, 13.40%, 13.50%, 13.60%, 13.70%, 13.80%, 13.90%, 14.00%, 14.10%, 14.20%, 14.30%, 14.40%, 14.50%, 14.60%, 14.70%, 14.80%, 14.90%, or 15.00% Zn. Optionally, the alloy may include from 4.00% to 4.10%, from 4.10% to 4.20%, from 4.20% to 4.30%, from 4.30% to 4.40%, from 4.40% to 4.50%, from 4.50% to 4.60%, from 4.60% to 4.70%, from 4.70% to 4.80%, from 4.80% to 4.90%, from 4.90% to 5.00%, from 5.00% to 5.10%, from 5.10% to 5.20%, from 5.20% to 5.30%, from 5.30% to 5.40%, from 5.40% to 5.50%, from 5.50% to 5.60%, from 5.60% to 5.70%, from 5.70% to 5.80%, from 5.80% to 5.90%, from 5.90% to 6.00%, from 6.00% to 6.10%, from 6.10% to 6.20%, from 6.20% to 6.30%, from 6.30% to 6.40%, from 6.40% to 6.50%, from 6.50% to 6.60%, from 6.60% to 6.70%, from 6.70% to 6.80%, from 6.80% to 6.90%, from 6.90% to 7.00%, from 7.00% to 7.10%, from 7.10% to 7.20%, from 7.20% to 7.30%, from 7.30% to 7.40%, from 7.40% to 7.50%, from 7.50% to 7.60%, from 7.60% to 7.70%, from 7.70% to 7.80%, from 7.80% to 7.90%, from 7.90% to 8.00%, from 8.00% to 8.10%, from 8.10% to 8.20%, from 8.20% to 8.30%, from 8.30% to 8.40%, from 8.40% to 8.50%, from 8.50% to 8.60%, from 8.60% to 8.70%, from 8.70% to 8.80%, from 8.80% to 8.90%, from 8.90% to 9.00%, from 9.00% to 9.10%, from 9.10% to 9.20%, from 9.20% to 9.30%, from 9.30% to 9.40%, from 9.40% to 9.50%, from 9.50% to 9.60%, from 9.60% to 9.70%, from 9.70% to 9.80%, from 9.80% to 9.90%, from 9.90% to 10.00%, from 10.00% to 10.10%, from 10.10% to 10.20%, from 10.20% to 10.30%, from 10.30% to 10.40%, from 10.40% to 10.50%, from 10.50% to 10.60%, from 10.60% to 10.70%, from 10.70% to 10.80%, from 10.80% to 10.90%, from 10.90% to 11.00%, from 11.00% to 11.10%, from 11.10% to 11.20%, from 11.20% to 11.30%, from 11.30% to 11.40%, from 11.40% to 11.50%, from 11.50% to 11.60%, from 11.60% to 11.70%, from 11.70% to 11.80%, from 11.80% to 11.90%, from 11.90% to 12.00%, from 12.00% to 12.10%, from 12.10% to 12.20%, from 12.20% to 12.30%, from 12.30% to 12.40%, from 12.40% to 12.50%, from 12.50% to 12.60%, from 12.60% to 12.70%, from 12.70% to 12.80%, from 12.80% to 12.90%, from 12.90% to 13.00%, from 13.00% to 13.10%, from 13.10% to 13.20%, from 13.20% to 13.30%, from 13.30% to 13.40%, from 13.40% to 13.50%, from 13.50% to 13.60%, from 13.60% to 13.70%, from 13.70% to 13.80%, from 13.80% to 13.90%, from 13.90% to 14.00%, from 14.00% to 14.10%, from 14.10% to 14.20%, from 14.20% to 14.30%, from 14.30% to 14.40%, from 14.40% to 14.50%, from 14.50% to 14.60%, from 14.60% to 14.70%, from 14.70% to 14.80%, from 14.80% to 14.90%, or from 14.90% to 15.00% Zn. All are expressed in wt. %.
In some examples, the alloys described may include copper (Cu) in an amount of from 0.10% to 3.5% (e.g., from 0.20% to 2.6%, from 0.30% to 2.5%, or from 0.15% to 0.60%) based on the total weight of the alloy. For example, the alloy may include 0.10%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, 0.20%, 0.21%, 0.22%, 0.23%, 0.24%, 0.25%, 0.26%, 0.27%, 0.28%, 0.29%, 0.30%, 0.35%, 0.4%, 0.45%, 0.50%, 0.55%, 0.60%, 0.65%, 0.70%, 0.75%, 0.80%, 0.85%, 0.90%, 0.95%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2.0%, 2.1%, 2.2%, 2.3%, 2.4%, 2.5%, 2.6%, 2.7%, 2.8%, 2.9%, 3.0%, 3.1%, 3.2%, 3.3%, 3.4%, or 3.5% Cu. Optionally, the alloy may include from 0.10% to 0.11%, from 0.11% to 0.12%, from 0.12% to 0.13%, from 0.13% to 0.14%, from 0.14% to 0.15%, from 0.15% to 0.16%, from 0.16% to 0.17%, from 0.17% to 0.18%, from 0.18% to 0.19%, from 0.19% to 0.20%, from 0.20% to 0.21%, from 0.21% to 0.22%, from 0.22% to 0.23%, from 0.23% to 0.24%, from 0.24% to 0.25%, from 0.25% to 0.26%, from 0.26% to 0.27%, from 0.27% to 0.28%, from 0.28% to 0.29%, from 0.29% to 0.30%, from 0.30% to 0.35%, from 0.35% to 0.40%, from 0.40% to 0.45%, from 0.45% to 0.50%, from 0.50% to 0.55%, from 0.55% to 0.60%, from 0.60% to 0.65%, from 0.65% to 0.70%, from 0.70% to 0.75%, from 0.75% to 0.80%, from 0.80% to 0.85%, from 0.85% to 0.90%, from 0.90% to 0.95%, from 0.95% to 1.0%, from 1.0% to 1.1%, from 1.1% to 1.2%, from 1.2% to 1.3%, from 1.3% to 1.4%, from 1.4% to 1.5%, from 1.5% to 1.6%, from 1.6% to 1.7%, from 1.7% to 1.8%, from 1.8% to 1.9%, from 1.9% to 2.0%, from 2.0% to 2.1%, from 2.1% to 2.2%, from 2.2% to 2.3%, from 2.3% to 2.4%, from 2.4% to 2.5%, from 2.5% to 2.6%, from 2.6% to 2.7%, from 2.7% to 2.8%, from 2.8% to 2.9%, from 2.9% to 3.0%, from 3.0% to 3.1%, from 3.1% to 3.2%, from 3.2% to 3.3%, from 3.3% to 3.4%, or from 3.4% to 3.5% Cu. All are expressed in wt. %.
In some examples, the alloys described herein may include magnesium (Mg) in an amount of from 1.00% to 4.00% (e.g., from 1.00% to 3.00%, from 1.40% to 2.80%, or from 1.60% to 2.60%). In some cases, the alloy can include 1.00%, 1.10%, 1.20%, 1.30%, 1.40%, 1.50%, 1.60%, 1.70%, 1.80%, 1.90%, 2.00%, 2.10%, 2.20%, 2.30%, 2.40%, 2.50%, 2.60%, 2.70%, 2.80%, 2.90%, 3.00%, 3.10%, 3.20%, 3.30%, 3.40%, 3.50%, 3.60%, 3.70%, 3.80%, 3.90%, or 4.00% Mg. Optionally, the alloy can include from 1.00% to 1.10%, from 1.10% to 1.20%, from 1.20% to 1.30%, from 1.30% to 1.40%, from 1.40% to 1.50%, from 1.50% to 1.60%, from 1.60% to 1.70%, from 1.80% to 1.80%, from 1.80% to 1.90%, from 1.90% to 2.00%, from 2.00% to 2.10%, from 2.10% to 2.20%, from 2.20% to 2.30%, from 2.30% to 2.40%, from 2.40% to 2.50%, from 2.50% to 2.60%, from 2.60% to 2.70%, from 2.70% to 2.80%, from 2.80% to 2.90%, from 2.90% to 3.00%, from 3.00% to 3.10%, from 3.10% to 3.20%, from 3.20% to 3.30%, from 3.30% to 3.40%, from 3.40% to 3.50%, from 3.50% to 3.60%, from 3.60% to 3.70%, from 3.70% to 3.80%, from 3.80% to 3.90%, or from 3.90% to 4.00% Mg. All are expressed in wt. %.
Optionally, the combined content of Zn, Cu, and Mg may range from 5.00% to 14.00% (e.g., from 5.50% to 13.50%, from 6.00% to 13.00%, from 6.50% to 12.50%, or from 7.00% to 12.00%). For example, the combined content of Zn, Cu, and Mg may be 5.00%, 5.50%, 6.00%, 6.50%, 7.00%, 7.50%, 8.00%, 8.50%, 9.00%, 9.50%, 10.00%, 10.50%, 11.00%, 11.50%, 12.00%, 12.50%, 13.00%, 13.50%, or 14.00%. Optionally, the combined content of Zn, Cu, and Mg may be from 5.00% to 5.50%, from 5.50% to 6.00%, from 6.00% to 6.50%, from 6.50% to 7.00%, from 7.00% to 7.50%, from 7.50% to 8.00%, from 8.00% to 8.50%, from 8.50% to 9.00%, from 9.00% to 9.50%, from 9.50% to 10.00%, from 10.00% to 10.50%, from 10.50% to 11.00%, from 11.00% to 11.50%, from 11.50% to 12.00%, from 12.00% to 12.50%, from 12.50% to 13.00%, from 13.00% to 13.50%, or from 13.50% to 14.00%. All are expressed in wt. %.
In some examples, the alloys described herein may include iron (Fe) in an amount of from 0.05% to 0.50% (e.g., from 0.10% to 0.35% or from 0.10% to 0.25%) based on the total weight of the alloy. For example, the alloy may include 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.10%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, 0.20%, 0.21%, 0.22%, 0.23%, 0.24%, 0.25%, 0.26%, 0.27%, 0.28%, 0.29%, 0.30%, 0.31%, 0.32%, 0.33%, 0.34%, 0.35%, 0.36%, 0.37%, 0.38%, 0.39%, 0.40%, 0.41%, 0.42%, 0.43%, 0.44%, 0.45%, 0.46%, 0.47%, 0.48%, 0.49%, or 0.50% Fe. Optionally, the alloy may include from 0.05% to 0.06%, from 0.06% to 0.07%, from 0.07% to 0.08%, from 0.08% to 0.09%, from 0.09% to 0.10%, from 0.10% to 0.11%, from 0.11% to 0.12%, from 0.12% to 0.13%, from 0.13% to 0.14%, from 0.14% to 0.15%, from 0.15% to 0.16%, from 0.16% to 0.17%, from 0.17% to 0.18%, from 0.18% to 0.19%, from 0.19% to 0.20%, from 0.20% to 0.21%, from 0.21% to 0.22%, from 0.22% to 0.23%, from 0.23% to 0.24%, from 0.24% to 0.25%, from 0.25% to 0.26%, from 0.26% to 0.27%, from 0.27% to 0.28%, from 0.28% to 0.29%, from 0.29% to 0.30%, from 0.30% to 0.31%, from 0.31% to 0.32%, from 0.32% to 0.33%, from 0.33% to 0.34%, from 0.34% to 0.35%, from 0.35% to 0.36%, from 0.36% to 0.37%, from 0.37% to 0.38%, from 0.38% to 0.39%, from 0.39% to 0.40%, from 0.40% to 0.41%, from 0.41% to 0.42%, from 0.42% to 0.43%, from 0.44% to 0.44%, from 0.44% to 0.45%, from 0.45% to 0.46%, from 0.46% to 0.47%, from 0.47% to 0.48%, from 0.48% to 0.49%, or from 0.49% to 0.50% Fe. All are expressed in wt. %.
In some examples, the alloys described herein may include silicon (Si) in an amount of from 0.05% to 0.30% (e.g., from 0.05% to 0.25% or from 0.07% to 0.15%) based on the total weight of the alloy. For example, the alloy may include 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.10%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, 0.20%, 0.21%, 0.22%, 0.23%, 0.24%, 0.25%, 0.26%, 0.27%, 0.28%, 0.29%, or 0.30% Si. Optionally, the alloy may include from 0.05% to 0.06%, from 0.06% to 0.07%, from 0.07% to 0.08%, from 0.08% to 0.09%, from 0.09% to 0.10%, from 0.10% to 0.11%, from 0.11% to 0.12%, from 0.12% to 0.13%, from 0.13% to 0.14%, from 0.14% to 0.15%, from 0.15% to 0.16%, from 0.16% to 0.17%, from 0.17% to 0.18%, from 0.18% to 0.19%, from 0.19% to 0.20%, from 0.20% to 0.21%, from 0.21% to 0.22%, from 0.22% to 0.23%, from 0.23% to 0.24%, from 0.24% to 0.25%, from 0.25% to 0.26%, from 0.26% to 0.27%, from 0.27% to 0.28%, from 0.28% to 0.29%, or from 0.29% to 0.30% Si. All are expressed in wt. %.
In some examples, the alloys described herein may include zirconium (Zr) in an amount of from 0.01% to 0.25% (e.g., from 0.01% to 0.20%, from 0.05% to 0.25%, from 0.025% to 0.20%, from 0.025% to 0.15%, from 0.05% to 0.20% or from 0.09% to 0.15%) based on the total weight of the alloy. For example, the alloy may include 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.10%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, 0.20%, 0.21%, 0.22%, 0.23%, 0.24%, or 0.25% Zr. Optionally, the alloy may include from 0.01% to 0.02%, from 0.02% to 0.03%, from 0.03% to 0.04%, from 0.04% to 0.05%, from 0.05% to 0.06%, from 0.06% to 0.07%, from 0.07% to 0.08%, from 0.08% to 0.09%, from 0.09% to 0.10%, from 0.10% to 0.11%, from 0.11% to 0.12%, from 0.12% to 0.13%, from 0.13% to 0.14%, from 0.14% to 0.15%, from 0.15% to 0.16%, from 0.16% to 0.17%, from 0.17% to 0.18%, from 0.18% to 0.19%, from 0.19% to 0.20%, from 0.20% to 0.21%, from 0.21% to 0.22%, from 0.22% to 0.23%, from 0.23% to 0.24%, or from 0.24% to 0.25% Zr. All are expressed in wt. %.
In some examples, the alloys described herein may include manganese (Mn) in an amount of up to 0.25% (e.g., from 0.01% to 0.10% or from 0.02% to 0.05%) based on the total weight of the alloy. For example, the alloy may include 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.10%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, 0.20%, 0.21%, 0.22%, 0.23%, 0.24%, or 0.25% Mn. Optionally, the alloy may include from 0.01% to 0.02%, from 0.02% to 0.03%, from 0.03% to 0.04%, from 0.04% to 0.05%, from 0.05% to 0.06%, from 0.06% to 0.07%, from 0.07% to 0.08%, from 0.08% to 0.09%, from 0.09% to 0.10%, from 0.10% to 0.11%, from 0.11% to 0.12%, from 0.12% to 0.13%, from 0.13% to 0.14%, from 0.14% to 0.15%, from 0.15% to 0.16%, from 0.16% to 0.17%, from 0.17% to 0.18%, from 0.18% to 0.19%, from 0.19% to 0.20%, from 0.20% to 0.21%, from 0.21% to 0.22%, from 0.22% to 0.23%, from 0.23% to 0.24%, or from 0.24% to 0.25% Mn. In some cases, Mn may not be present in the alloy (i.e., 0.0%). All are expressed in wt. %.
In some examples, the alloys described herein may include chromium (Cr) in an amount of up to 0.20% (e.g., from 0.01% to 0.10%, from 0.01% to 0.05%, or from 0.03% to 0.05%) based on the total weight of the alloy. For example, the alloy may include 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.10%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, or 0.20% Cr. Optionally, the alloy may include from 0.01% to 0.02%, from 0.02% to 0.03%, from 0.03% to 0.04%, from 0.04% to 0.05%, from 0.05% to 0.06%, from 0.06% to 0.07%, from 0.07% to 0.08%, from 0.08% to 0.09%, from 0.09% to 0.10%, from 0.10% to 0.11%, from 0.11% to 0.12%, from 0.12% to 0.13%, from 0.13% to 0.14%, from 0.14% to 0.15%, from 0.15% to 0.16%, from 0.16% to 0.17%, from 0.17% to 0.18%, from 0.18% to 0.19%, or from 0.19% to 0.20% Cr. In some cases, Cr may not be present in the alloy (i.e., 0.0%). All are expressed in wt. %.
In some examples, the alloys described herein may include titanium (Ti) in an amount of up to 0.15% (e.g., from 0.001% to 0.10%, from 0.001% to 0.05%, or from 0.003% to 0.035%) based on the total weight of the alloy. For example, the alloy may include 0.001%, 0.002%, 0.003%, 0.004%, 0.005%, 0.006%, 0.007%, 0.008%, 0.009%, 0.010%, 0.011% 0.012%, 0.013%, 0.014%, 0.015%, 0.016%, 0.017%, 0.018%, 0.019%, 0.020%, 0.021% 0.022%, 0.023%, 0.024%, 0.025%, 0.026%, 0.027%, 0.028%, 0.029%, 0.03%, 0.031% 0.032%, 0.033%, 0.034%, 0.035%, 0.036%, 0.037%, 0.038%, 0.039%, 0.04%, 0.041% 0.042%, 0.043%, 0.044%, 0.045%, 0.046%, 0.047%, 0.048%, 0.049%, 0.05%, 0.055%, 0.06%, 0.065%, 0.07%, 0.075%, 0.08%, 0.085%, 0.09%, 0.095%, 0.10%, 0.11%, 0.12%, 0.13%, 0.14%, or 0.15% Ti. Optionally, the alloy may include from 0.01% to 0.02%, from 0.02% to 0.03%, from 0.03% to 0.04%, from 0.04% to 0.05%, from 0.05% to 0.06%, from 0.06% to 0.07%, from 0.07% to 0.08%, from 0.08% to 0.09%, from 0.09% to 0.10%, from 0.10% to 0.11%, from 0.11% to 0.12%, from 0.12% to 0.13%, from 0.13% to 0.14%, or from 0.14% to 0.15% Ti. In some cases, Ti may not be present in the alloy (i.e., 0.0%). All are expressed in wt. %.
In some examples, the alloys described herein may include one or more rare earth elements (i.e., one or more of Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) in an amount of up to 0.20% (e.g., from 0.01% to 0.20%, from 0.01% to 0.15%, from 0.01% to 0.10%, from 0.01% to 0.05%, or from 0.03% to 0.05%) based on the total weight of the alloy. For example, the alloy may include 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.10%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, or 0.20% of the rare earth elements. Optionally, the alloy may include from 0.01% to 0.02%, from 0.02% to 0.03%, from 0.03% to 0.04%, from 0.04% to 0.05%, from 0.05% to 0.06%, from 0.06% to 0.07%, from 0.07% to 0.08%, from 0.08% to 0.09%, from 0.09% to 0.10%, from 0.10% to 0.11%, from 0.11% to 0.12%, from 0.12% to 0.13%, from 0.13% to 0.14%, from 0.14% to 0.15%, from 0.15% to 0.16%, from 0.16% to 0.17%, from 0.17% to 0.18%, from 0.18% to 0.19%, or from 0.19% to 0.20% of the rare earth elements. All are expressed in wt. %.
In some examples, the alloys described herein may include one or more of Mo, Nb, Be, B, Co, Sn, Sr, V, In, Hf, Ag, and Ni in an amount of up to 0.20% (e.g., from 0.01% to 0.20% or from 0.05% to 0.15%) based on the total weight of the alloy. For example, the alloy may include 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.10%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, or 0.20% of one or more of Mo, Nb, Be, B, Co, Sn, Sr, V, In, Hf, Ag, and Ni. Optionally, the alloy may include from 0.01% to 0.02%, from 0.02% to 0.03%, from 0.03% to 0.04%, from 0.04% to 0.05%, from 0.05% to 0.06%, from 0.06% to 0.07%, from 0.07% to 0.08%, from 0.08% to 0.09%, from 0.09% to 0.10%, from 0.10% to 0.11%, from 0.11% to 0.12%, from 0.12% to 0.13%, from 0.13% to 0.14%, from 0.14% to 0.15%, from 0.15% to 0.16%, from 0.16% to 0.17%, from 0.17% to 0.18%, from 0.18% to 0.19%, or from 0.19% to 0.20% of one or more of Mo, Nb, Be, B, Co, Sn, Sr, V, In, Hf, Ag, and Ni. All are expressed in wt. %.
Optionally, the alloy compositions described herein may further include other minor elements, sometimes referred to as impurities, for example in amounts of 0.05% or below, 0.04% or below, 0.03% or below, 0.02% or below, or 0.01% or below. These impurities may include, but are not limited to Ga, Ca, Bi, Na, Pb, or combinations thereof. Accordingly, Ga, Ca, Bi, Na, or Pb may be present in alloys in amounts of 0.05% or below, 0.04% or below, 0.03% or below, 0.02% or below, or 0.01% or below. The sum of all impurities may not exceed 0.15% (e.g., 0.10%). All expressed in wt. %. The remaining percentage or remainder of any alloy may be aluminum.
Aluminum alloy product 210 of
While
In graph 405, corrosion depth exhibited at various quench rates for a quench-sensitive aluminum alloy product are provided. Graph 405 may correspond to aluminum alloy product 110 and represents an AA7075 aluminum alloy product. As previously discussed with respect to
Graph 405 also indicates the corrosion depth. Corrosion depth may refer to the extent to which corrosion is exhibited into the bulk of the aluminum alloy from a surface of the aluminum alloy product. In other words, corrosion depth may refer to a depth into the bulk of the aluminum alloy product at which corrosion may be present upon corrosion testing. Graph 405 may include or represent data from multiple quench tests for each quench rate or from multiple locations on the corrosion tested samples. As such, the blocks may correspond to an average corrosion depth observed and standard deviation or error bars may indicate the full range of corrosion depth observed during testing.
As illustrated in graph 405, as the quench rate decreases, the depth of corrosion may increase. Limiting corrosion may be desirable and thus a lower corrosion depth may be desirable as well. As illustrated in graph 405, at a quench rate of 550° C./s, corrosion 420 may extend to an average depth of about 50 μm into the aluminum alloy product and may correspond to pitting corrosion, for example. When the quench rate is slowed to 350° C./s, corrosion 420 may extend even further into the aluminum alloy product to an average depth of about 75 μm, and again may correspond to pitting corrosion. When the corrosion morphology changes to intergranular corrosion, the corrosion depth may continue to increase. While the corrosion depth for corrosion 430 may decrease slightly when the aluminum alloy product is quenched at a rate of 150° C./s, this point includes large error bars where the maximum corrosion depth is quite large. The average corrosion depth of corrosion 430 for quench rates of from 5° C./s to 250° C./s may still be greater than the corrosion depth at rapid quench rates, such as 550° C./s. Even at a slow quench rate of 5° C./s, corrosion may extend to a corrosion depth of about 85 μm.
Graphs 410 and 415 illustrate corrosion depths observed for additional aluminum alloy products according to the present disclosure. The aluminum alloy products for which data are shown in graphs 410 and 415 may be heat-treated aluminum alloy products. The heat-treated aluminum alloy product may be a quench-insensitive aluminum alloy product such as aluminum alloy products 210 and 310. The heat-treated aluminum alloy product observed may be an aluminum alloy product made according to the methods and compositions described herein. For example, such aluminum alloy products may be made from an aluminum alloy having the following elemental composition as provided in Table 5.
As illustrated in graph 410, when the aluminum alloy product 4A is quenched and subjected to corrosion testing, corrosion 420 may be observed for most of the quench rates. For example, pitting corrosion may be exhibited even at slow quench rates of 50° C./s or less. In the data obtained, when quench rates are slowed to 5° C./s, aluminum alloy product 4A exhibits intergranular corrosion 430 (IGC). Moreover, the corrosion exhibited by aluminum alloy product 4A for which data are shown in graph 410, regardless of the type of corrosion, generally has an overall reduced corrosion depth when compared with the quench-sensitive aluminum alloy product of graph 405. Even at the slowest quench rate of 5° C./s, a lower corrosion depth is observed. While the corrosion depth may increase somewhat as the quench rate decreases, the rate of increase in corrosion depth over the quench rates may be minimal. For example, the corrosion depth of corrosion 420 shown in graph 410 at a quench rate of 550° C./s may be about 40 μm, while the corrosion depth at a quench rate of 5° C./s is only slightly more, at about 50 μm. Overall, the corrosion depth shown in graph 410 is relatively constant when compared to the quench-sensitive aluminum alloy product of graph 405. Additionally, as indicated by the standard deviation bars, corrosion depth may also be relatively constant across multiple runs of the same test. The lack of deviation between different trial runs of the same tests (i.e., multiple quenches at the same quench rate) may further show the aluminum alloy product's insensitivity to quenching by indicating that changes in operating conditions may have minimal effect on corrosion susceptibility.
Graph 415 may indicate similar quenching insensitivity for another aluminum alloy product 4B as described herein. Similar to the aluminum alloy product 4A for which data are shown in graph 410, corrosion morphology for the aluminum alloy product represented by graph 415 may not change from pitting corrosion to intergranular corrosion until a quench rate of or below 5° C./s. Unexpectedly, corrosion depths may decrease in some cases as the quench rate decreases. This result is unexpected when comparing corrosion depth trends with respect to quench rates on graphs 405 and 410 which indicate an increase in corrosion depth with decreasing quench rates. In graph 415, rates from 50° C./s to 250° C./s may represent that pitting corrosion is the primary corrosion 420 extending to corrosion depths of about 25 μm or less. As illustrated by graphs 410 and 415, when quench rates of from 5° C./s to 550° C./s are used, corrosion depth upon corrosion testing may be from 0 μm to 300 μm, 5 μm to 300 μm, 0 μm to 200 μm, from 5 μm to 100 μm, or from 10 μm to 80 μm. For example, when the quench rate is 125° C./s the corrosion depth may be from 5 μm to 150 μm or from 25 μm to 50 μm.
As discussed previously, quench sensitivity may impact the properties of an aluminum alloy product, specifically the strength values. Exemplary strength characteristics may include yield strength, tensile strength, grain elongation, and strain ratio.
Each of the aluminum alloy products 5A, 5B, and C may be prepared prior to being subjected to the same mechanical testing procedure. To prepare aluminum alloy products 5A, 5B, and C, the aluminum alloy products may be solutionized to a first temperature of 480° C. The aluminum alloy products may be maintained or held at the first temperature for 5 minutes before being quenched in water baths maintained at temperatures of 25° C., 55° C., 65° C., 75° C., 85° C. to achieve quench rates of 550° C./s, 350° C./s, 250° C./s, 150° C./s, and 50° C./s, respectively. To achieve the quench rate of 5° C./s, the aluminum alloy products may be air quenched. After quenching, the aluminum alloy products may be subjected to a one step aging process. An exemplary aging process may include a T6 or T7 temper or precipitation hardening. For the graphs in
As shown on graph 500, aluminum alloy products 5A and 5B made from the quench insensitive 7xxx series aluminum alloy compositions, as provided above and made according to the techniques provided herein, may exhibit superior yield strength when compared to aluminum alloy product C. For example, aluminum alloy products 5A and 5B may exhibit yield strengths from 400 MPa to 600 MPa. Specifically, aluminum alloy products 5A and 5B may exhibit yield strengths from 500 MPa to 650 MPa at quench rates from 50° C./s to 550° C./s. For example, aluminum alloy products 5A and 5B may exhibit a yield strength of from 560 MPa to 580 MPa when the quench rate is 125° C./s. In some embodiments, quench insensitive aluminum alloy products may exhibit yield strengths from about 550 MPa to about 600 MPa at quench rates from 50° C./s to 550° C./s or yield strengths from about 525 MPa to about 600 MPa at quench rates from 350° C./s to 550° C./s. For example, at a quench rate of 550° C./s, aluminum alloy products 5A and 5B may exhibit a yield strength of about 572 MPa and about 579 MPa, respectively. In comparison, aluminum alloy product C may exhibit a yield strength of about 532 MPa at a quench rate of 550° C./s. At quench rates of 350° C./s and 50° C./s, aluminum alloy product 5A may exhibit yield strengths of about 572 MPa and 553 MPa, respectively, and aluminum alloy product 5B may exhibit yield strengths of about 575 MPa and 569 MPa, respectively. In comparison, aluminum alloy product C may exhibit yield strengths of about 524 and 509 at quench rates of 350° C./s and 50° C./s, respectively.
The improved yield strength of aluminum alloy products 5A and 5B may be even more evident at low quench rates, such as the quench rate of 5° C./s. At a quench rate of 5° C./s, aluminum alloy products 5A and 5B exhibit yield strengths of about 439 MPa and 489 MPa, which may be almost 100 MPa higher than the yield strength of aluminum alloy product C at a quench rate of 5° C./s. At 5° C./s, aluminum alloy product C exhibits a yield strength of about 347 MPa. Advantageously, aluminum alloy products 5A and 5B exhibit a drop in yield strength of less than 25% when the quench rate is slowed from 550° C./s to 5° C./s. In comparison, aluminum alloy product C exhibits a drop of over 25%, such as for example 35%, when the quench rate is slowed from 550° C./s to 5° C./s.
Similar to yield strength, aluminum alloy products 5A and 5B may exhibit superior ultimate tensile strength over various quench rates when compared with aluminum alloy product C. As shown on graph 600, aluminum alloy products 5A and 5B exhibit ultimate tensile strengths (also referred to herein as tensile strengths) from 500 MPa to 650 MPa at quench rates from 5° C./s to 550° C./s. For example, aluminum alloy products 5A and 5B may exhibit an ultimate tensile strength of from 605 MPa to 615 MPa when the quench rate is 125° C./s. In some embodiments, quench insensitive aluminum alloy products may exhibit tensile strengths from 585 MPa to 625 MPa at quench rates from 50° C./s to 550° C./s. For example, at a quench rate of 550° C./s, aluminum alloy products A and B exhibit tensile strengths of about 614 MPa and about 618 MPa, respectively. In comparison, aluminum alloy product C exhibits a tensile strength of about 584 MPa at a quench rate of 550° C./s. At quench rates of 350° C./s and 50° C./s, aluminum alloy product 5A exhibits tensile strengths of about 614 MPa and about 593 MPa, respectively, and aluminum alloy product 5B exhibits tensile strengths of about 618 MPa and about 605 MPa, respectively. In comparison, aluminum alloy product C exhibits tensile strengths of about 578 MPa and about 566 MPa at quench rates of 350° C./s and 50° C./s, respectively.
Even at slow quench rates, such as 5° C./s, aluminum alloy products 5A and 5B exhibit higher tensile strengths as compared to aluminum alloy product C. For example, at a quench rate of 5° C./s, quench insensitive aluminum alloy products may exhibit tensile strengths of from about 475 MPa to about 550 MPa. As illustrated in
Turning now to
As illustrated by graph 700, aluminum alloy products 5A and 5B may exhibit a total elongation from 10.00% to 15.00% for quench rates from 5° C./s to 550° C./s. For example, at rapid quench rates, such as 550° C./s, aluminum alloy products 5A and 5B exhibit a total elongation of about 14.70% and about 14.31%, respectively. As the quench rate is slowed to 350° C./s, 50° C./s, and 5° C./s, aluminum alloy product 5A exhibits a total elongation of about 15.10%, about 13.29%, and about 10.46%, respectively. Similarly, aluminum alloy product 5B exhibits a total elongation of 14.48%, 13.65%, and 10.15% when the quench rate is slowed to 350° C./s, 50° C./s, and 5° C./s, respectively. When the quench rate is 125° C./s, aluminum alloy products 5A and 5B may exhibit a total elongation of from 13.80% to 14.20%. In some cases, quench insensitive aluminum alloy products may exhibit a uniform elongation of from 7.50% to 10.50%. For example, aluminum alloy products 5A and 5B may exhibit a uniform elongation of from 9.00% to 9.60% when the quench rate is 125° C./s.
As illustrated in
In embodiments, quench insensitive aluminum alloy products may exhibit a strain ratio from 0.3 to 1.0 for quench rates from 5° C./s to 550° C./s. In other embodiments, the strain ratios may be from 0.5 to 1.0 when quench insensitive aluminum alloy products are quenched at rates from 250° C./s to 500° C./s. When the quench rate is 125° C./s, aluminum alloy products 5A and 5B may exhibit a strain ratio of 0.375 to 0.425. For example, when aluminum alloy products 5A and 5B are quenched at a rapid rate of 550° C./s, the strain ratio may be from 0.5 to 1.0. As illustrated by graph 800, for all of the quench rates tested, aluminum alloy products 5A and 5B may exhibit a strain ratio above 0.3. In comparison, strain ratios exhibited by aluminum alloy product C may be below 0.3 across all of the quench rates tested. This may indicate that aluminum alloy product C is more susceptible to stress corrosion cracking than aluminum alloy products 5A and 5B.
As illustrated by graph 900, the width of precipitate-free zones formed during an aging process may increase as quench rate decreases. Aluminum alloy product C may exhibit larger precipitate-free zones during quenching when compared with aluminum alloy products 5A and 5B. For example, at rapid quenching rates, such as 550° C./s, aluminum alloy product C may exhibit precipitate-free zones having an average width of about 45 nm. In comparison, at a quench rate of 550° C./s, aluminum alloy products 5A and 5B may exhibit precipitate-free zones having an average width of about 35 nm and 32 nm, respectively. Even at slow quench rates, aluminum alloy product C may exhibit larger precipitate-free zones than aluminum alloy products 5A and 5B. For example, at 5° C./s, aluminum alloy product C may exhibit precipitate-free zones having an average width of about 200 nm, whereas aluminum alloy products 5A and 5B may exhibit precipitate-free zones having an average width of about 90 nm and 150 nm, respectively.
It should be noted that while the above discussed improved corrosion resistance and mechanical properties are provided with reference to discrete quench rates, this is not meant to be limiting. Similar properties may be exhibited for a range of quench rates. The improved corrosion resistance and mechanical properties described with reference to
At block 1210, the rolled aluminum alloy product may be heated. The rolled aluminum alloy product may be a quench-insensitive aluminum alloy product. In embodiments, the rolled aluminum alloy product may include an aluminum alloy having an elemental composition according to those provided in Tables 1-6. Optionally, the rolled aluminum alloy product may include a 7xxx series aluminum alloy. In embodiments, the rolled aluminum alloy product may be a slab, strip, plate, shate, or sheet. Optionally, ingots and/or billets may be used with method 1200.
The rolled aluminum alloy product may be heated to a first temperature at block 1210. The rolled aluminum alloy product may be heated during a heat treatment process. In some embodiments, the heat treatment process may be a solutionizing heat treatment process. During heating, the rolled aluminum alloy product may be heated to a first temperature of at least of at least 400° C. (e.g., at least 425° C., at least 450° C., at least 460° C., or at least 465° C.). In some cases, the first temperature may range from 400° C. to 525° C., 425° C. to 510° C., 450° C. to 510° C., 450° C. to 500° C., 450° C. to 480° C., or 450° C. to 475° C. The first temperature may be a solutionizing temperature in some embodiments.
During heating the rolled aluminum alloy product, the heating rate to the first temperature may be 70° C./hour or less, 60° C./hour or less, or 50° C./hour or less. The rolled aluminum alloy product may then be allowed to soak (i.e., held at the indicated first temperature) for a period of time. In some cases, the rolled aluminum alloy product may be allowed to soak for up to 15 hours (e.g., from 30 minutes to 15 hours, inclusively). For example, the rolled aluminum alloy product may be soaked at the first temperature of at least 400° C. for 30 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, 13 hours, 14 hours, or 15 hours.
In embodiments, the heat treatment process may be or include a hot rolling process. The hot rolling process may include a hot reversing mill operation and/or a hot tandem mill operation. The hot rolling process may be performed at a temperature ranging from about 250° C. to about 550° C. (e.g., from about 300° C. to about 500° C. or from about 350° C. to about 450° C.). In the hot rolling process, the rolled aluminum alloy product may be hot rolled to a 12 mm thick gauge or less (e.g., from 3 mm to 8 mm thick gauge). For example, the rolled aluminum alloy product may be hot rolled to a 11 mm thick gauge or less, 10 mm thick gauge or less, 9 mm thick gauge or less, 8 mm thick gauge or less, 7 mm thick gauge or less, 6 mm thick gauge or less, 5 mm thick gauge or less, 4 mm thick gauge or less, or 3 mm thick gauge or less. In some embodiments, the hot rolling process may occur at a different point during method 1200. For example, the hot rolling process may occur after a forming or after a quenching step.
The rolled aluminum alloy product may be maintained at the first temperature, or within 10° C. of the first temperature, for a time duration of from 30 seconds to 12 hours at block 1220. In some cases, the time duration may be from 15 seconds to 6 hours, 15 seconds to 3 hours, 15 seconds to 1 hour, 15 seconds to 30 minutes, 15 seconds to 5 minutes, 15 seconds to 1 hour, 15 seconds to 30 seconds, 30 seconds to 6 hours, 30 seconds to 3 hours, 30 seconds to 1 hour, 30 seconds to 30 minutes, 30 seconds to 5 minutes, 30 seconds to 1 minute, 1 minute to 6 hours, 1 minute to 3 hours, 1 minute to 1 hour, 1 minute to 30 minutes, 5 minutes to 1 hour, 5 minutes to 30 minutes, 30 minutes to 12 hours, 30 minutes to 6 hours, or 30 minutes to 1 hour. Optionally, the rolled aluminum alloy product may be maintained within 50° C. of the first temperature, within 40° C. of the first temperature, within 30° C. of the first temperature, within 25° C. of the first temperature, within 20° C. of the first temperature, within 15° C. of the first temperature, within 5° C. of the first temperature, or within 1° C. of the first temperature for the specified time duration.
At the end of the heat treatment process, the rolled aluminum alloy product may optionally be subjected to one or more forming processes at block 1230. For example, at block 1230, the rolled aluminum alloy product may be subjected to a hot forming process. In some embodiments, the rolled aluminum alloy product may be hot formed after heating but before the rolled aluminum alloy product is quenched. The rolled aluminum alloy product as provided herein may have good ductility or formability at elevated temperatures. This may allow for the rolled aluminum alloy product to be malleable and achieve better formability. Hot forming the rolled aluminum alloy product when the product is at or near the first temperature may allow for the rolled aluminum alloy product to be formed into a variety of complex shapes. For example, after heating the rolled aluminum alloy product, the product may be transferred to a press or die where it is formed into a desired shape.
The rolled (and optionally formed) aluminum alloy product may be quenched at block 1240. At block 1240, the rolled aluminum alloy product may be quenched to a second temperature of from about 10° C. to about 100° C. in a quenching process to generate a heat-treated aluminum alloy product. The second temperature may be ambient or room temperature in some embodiments. The quenching process may be performed using a rapid quenching practice or a slow quenching practice. The quenching rate in the rapid quenching practice may range from about 2,000° C. per second to about 3,000° C. per second (e.g., about 2,500° C. per second) or more. The quenching rate in the slow quenching practice may range from about 5° C. per second to about 600° C. per second (e.g., from about 5° C. per second to about 550° C. per second or from about 50° C. per second to about 350° C. per second). In some cases, the quenching rate may range from about 5° C. per second to about 125° C. per second.
In some embodiments, quenching the rolled aluminum alloy product at block 1240 may include two or more quenching processes. The rolled aluminum alloy product may be subjected to a first quenching to an intermediate temperature and then subjected to a second quenching until the rolled aluminum alloy product reaches the second temperature. For example, the rolled aluminum alloy product may be quenched from the first temperature to an intermediate temperature via a hot forming process. The intermediate temperature may be above the second temperature. Thus, a second quenching may be required to quench the rolled aluminum alloy product to the second temperature. The second quenching rate may be greater than the first quenching rate.
The heat-treated aluminum alloy product generated by the quenching process may exhibit superior mechanical properties over conventional aluminum alloy products. Specifically, the heat-treated aluminum alloy product as described herein may exhibit a strain ratio of from 0.3 to 0.8. The strain ratio may be determined according to an ASTM G129, an ASTM G129, and/or other standard test method. Other exemplary mechanical properties exhibited by the heat-treated aluminum alloy product may include an ultimate tensile strength of from 500 MPa to 650 MPa, a yield strength of from 400 MPa to 600 MPa, a uniform elongation of from 7.50% to 10.50%, and a total elongation of from 10.00% to 15.00%. The heat-treated aluminum alloy generated at block 1240 may be aluminum alloy products 210, 310, or aluminum alloy products 4A and 4B discussed with reference to
At block 1242, quenching the rolled aluminum alloy product may include subjecting the rolled aluminum alloy product to a water quenching process. Water quenching processes may include cold water immersion, hot water immersion, boiling water, or water spray. In various embodiments, quenching the rolled aluminum alloy product at block 1240 may include other methods of quenching. For example, block 1240 may include a forced air quenching process. Forced air quenching processes may include air blasts or still air procedures. Other quench methods that may be used at block 1240 may include polyalkylene glycol solutions, liquid nitrogen, fast quenching oils, or brine solutions.
Optionally, blocks 1230 and 1240 may be combined. For example, in some cases, the rolled aluminum alloy product may be quenched via a die quenching process. During a hot forming process, the rolled aluminum alloy product may be formed into parts using cold dies. Because the cold dies are cooler than the heated rolled aluminum alloy product, the cold dies may provide rapid quenching to the rolled aluminum alloy product. In some cases, the hot forming process may be considered to be part of the quenching process. In other cases, the rolled aluminum alloy product may be subjected to the hot forming process before or after the quenching process. In further cases, the hot forming process may occur between a first quenching process and a second quenching process.
After the rolled aluminum alloy product is quenched at block 1240, the heat-treated aluminum alloy product may be subjected to an aging process at block 1250. For example, the heat-treated aluminum alloy product may be subjected to a hardening process such as in a T6 or T7 temper. In some embodiments, the aging process at block 1250 may include re-heating the heat-treated aluminum alloy product to a temperature from about 100° C. to about 170° C., maintaining the heat-treated aluminum alloy product at a temperature from about 100° C. to about 150° C. for a period of time, and cooling the sheet to a temperature near or at room temperature. In other cases, the aging process may include re-heating the heat-treated aluminum alloy product to a temperature from about 100° C. to about 150° C.; maintaining the heat-treated aluminum alloy product at a temperature from about 100° C. to about 150° C. for a period of time; heating the heat-treated aluminum alloy product to a temperature greater than about 150° C.; maintaining the heat-treated aluminum alloy product at a temperature greater than about 150° C. (e.g., from about 150° C. to about 170° C.) for a period of time; and cooling the heat-treated aluminum alloy product to room temperature. The heat-treated aluminum alloy product may be maintained at the temperature for a time period greater than 10 minutes, 20 minutes, 30 minutes, 40 minutes, 50 minutes, 60 minutes, 70 minutes, 80 minutes, 90 minutes, 100 minutes, 110 minutes, 2 hours, 6 hours, 12 hours, 18 hours, 24 hours, 30 hours, 32 hours, or 48 hours. For example, the heat-treated aluminum alloy product may be subjected to an aging process in which the product is re-heated to a temperature 100° C. to 170° C. and maintained at that temperature for 12 hours to 30 hours.
In some cases, the heat-treated aluminum alloy product may be subjected to paint bake heat treatment, for example, heating the heat-treated aluminum alloy product to a temperature greater than about 150° C. (e.g., 160° C., 170° C., 180° C., 190° C., 200° C., or higher) and maintaining the heat-treated aluminum alloy product at the temperature greater than about 140° C. (e.g., between about 150° C., 160° C., 170° C., 180° C., 190° C., 200° C., or higher) for a period of time (e.g., 10 minutes, 20 minutes, 30 minutes, 40 minutes, 50 minutes, 60 minutes, 70 minutes, 80 minutes, 90 minutes, 100 minutes, 110 minutes, or 120 minutes).
Turning now to
In some cases, the heat-treated aluminum alloy product may be subjected to an aging process. At step 1350, the heat-treated aluminum alloy product may be subjected to a T6 tempering process. Optionally, a T7 tempering process may be used. As provided on graph 1300, at step 1350 the heat-treated aluminum alloy product may be re-heated to a temperature of 125° C. The heat-treated aluminum alloy product may be maintained at 125° C. for 24 hours before returning to room temperature.
The aluminum alloy products described herein can be used in automotive applications and other transportation applications, including aircraft and railway applications. For example, the disclosed aluminum alloy products can be used to prepare automotive structural parts, such as bumpers, side beams, roof beams, cross beams, pillar reinforcements (e.g., A-pillars, B-pillars, and C-pillars), inner panels, outer panels, side panels, inner hoods, outer hoods, rockers, or trunk lid panels. The aluminum alloy products and methods described herein can also be used in aircraft or railway vehicle applications, to prepare, for example, external and internal panels. In some embodiments, the aluminum alloy products described herein can be incorporated within upper wing, lower wing, or other body assemblies for aerospace applications.
The aluminum alloy products and methods described herein can also be used in electronics applications or any other desired application. For example, the aluminum alloy products and methods described herein can be used to prepare housings for electronic devices, including mobile phones and tablet computers. In some examples, the aluminum alloy products can be used to prepare housings for the outer casing of mobile phones (e.g., smart phones), tablet bottom chassis, and other portable electronics.
Illustrations
As used below, any reference to a series of illustrations is to be understood as a reference to each of those examples disjunctively (e.g., “Illustrations 1-4” is to be understood as “Illustrations 1, 2, 3, or 4”).
Illustration 1 is a method of making an aluminum alloy product, the method comprising: heating a rolled aluminum alloy product to a first temperature of from 400° C. to 525° C. wherein the rolled aluminum alloy product comprises a 7xxx series aluminum alloy comprising: from 4.00 wt. % to 15.00 wt. % Zn, from 0.10 wt. % to 3.50 wt. % Cu, from 1.00 wt. % to 4.00 wt. % Mg, from 0.05 wt. % to 0.50 wt. % Fe, from 0.05 wt. % to 0.30 wt. % Si, from 0.05 wt. % to 0.25 wt. % Zr, up to 0.25 wt. % Mn, up to 0.20 wt. % Cr, up to 0.15 wt. % Ti, and Al; maintaining the rolled aluminum alloy product at the first temperature or within 10° C. of the first temperature for a time duration of from 15 seconds to 30 minutes; and quenching the rolled aluminum alloy product at a quench rate from 0.5° C./s to 125° C./s thereby generating a heat-treated aluminum alloy product, wherein the heat-treated aluminum alloy product exhibits a strain ratio of from 0.3 to 0.8, and wherein the strain ratio is determined according to an ASTM G129 and/or ASTM G139 standard test method.
Illustration 2 is the method of any previous or subsequent illustration, wherein the rolled aluminum alloy product is quenched until the rolled aluminum alloy product reaches a second temperature of from 10° C. to 100° C.
Illustration 3 is the method of any previous or subsequent illustration, wherein quenching comprising a first quenching at a first quench rate to an intermediate temperature, a second quenching at a second quench rate to the second temperature, wherein the second quench rate is greater than the first quench rate.
Illustration 4 is the method of any previous or subsequent illustration, wherein the quench rate is from 5° C./s to 125° C./s.
Illustration 5 is the method of any previous or subsequent illustration, wherein the quench rate is from 10° C./s to 125° C./s.
Illustration 6 is the method of any previous or subsequent illustration, wherein the rolled aluminum alloy product comprises: from 4.00 wt. % to 15.00 wt. % Zn, from 0.20 wt. % to 2.60 wt. % Cu, from 1.40 wt. % to 2.80 wt. % Mg, from 0.10 wt. % to 0.35 wt. % Fe, from 0.05 wt. % to 0.20 wt. % Si, from 0.05 wt. % to 0.15 wt. % Zr, from 0.01 wt. % to 0.05 wt. % Mn, from 0.01 wt. % to 0.05 wt. % Cr, from 0.001 wt. % to 0.05 wt. % Ti, and Al.
Illustration 7 is the method of any previous or subsequent illustration, wherein the rolled aluminum alloy product comprises: from 4.00 wt. % to 15.00 wt. % Zn, from 0.30 wt. % to 2.50 wt. % Cu, from 1.60 wt. % to 2.60 wt. % Mg, from 0.10 wt. % to 0.25 wt. % Fe, from 0.07 wt. % to 0.15 wt. % Si, from 0.09 wt. % to 0.15 wt. % Zr, from 0.02 wt. % to 0.05 wt. % Mn, from 0.03 wt. % to 0.05 wt. % Cr, from 0.003 wt. % to 0.035 wt. % Ti, and Al.
Illustration 8 is the method of any previous or subsequent illustration, wherein the rolled aluminum alloy product comprises: from 4.00 wt. % to 15.00 wt. % Zn, from 0.20 wt. % to 2.10 wt. % Cu, from 2.20 wt. % to 2.40 wt. % Mg, from 0.18 wt. % to 0.23 wt. % Fe, from 0.09 wt. % to 0.12 wt. % Si, from 0.05 wt. % to 0.15 wt. % Zr, from 0.04 wt. % to 0.09 wt. % Mn, from 0.03 wt. % to 0.09 wt. % Cr, from 0.01 wt. % to 0.02 wt. % Ti, up to 0.15 wt. % of impurities, and Al.
Illustration 9 is the method of any previous or subsequent illustration, wherein the rolled aluminum alloy product further comprises up to 0.20 wt. % of one or more of Mo, Nb, Be, B, Co, Sn, Sr, V, In, Hf, Ag, Sc and Ni.
Illustration 10 is the method of any previous or subsequent illustration, wherein the heat-treated aluminum alloy product exhibits a corrosion depth of from 5 μm to 300 μm as determined according to an ASTM G110 standard test method.
Illustration 11 is the method of any previous or subsequent illustration, wherein corrosion occurring within the corrosion depth comprises at least one of pitting corrosion or intergranular corrosion.
Illustration 12 is the method of any previous or subsequent illustration, wherein the corrosion comprises intergranular corrosion when the quench rate is 50° C./s or less.
Illustration 13 is the method of any previous or subsequent illustration, wherein the corrosion does not include intergranular corrosion when the quench rate is greater than 5° C./s.
Illustration 14 is the method of any previous or subsequent illustration, wherein the heat-treated aluminum alloy product exhibits a corrosion depth of from 25 μm to 50 μm when the quench rate is 125° C./s.
Illustration 15 is the method of any previous or subsequent illustration, wherein the first temperature is a solutionizing temperature.
Illustration 16 is the method of any previous or subsequent illustration, wherein the second temperature is ambient temperature.
Illustration 17 is the method of any previous or subsequent illustration, wherein heating and quenching the rolled aluminum alloy product correspond to a solutionizing heat treatment process.
Illustration 18 is the method of any previous or subsequent illustration, further comprising subjecting the rolled aluminum alloy product to a hot forming process after heating the rolled aluminum alloy product.
Illustration 19 is the method of any previous or subsequent illustration, wherein quenching the rolled aluminum alloy product comprises a die quenching process.
Illustration 20 is the method of any previous or subsequent illustration, wherein quenching the rolled aluminum alloy product comprises a water quenching process.
Illustration 21 is the method of any previous or subsequent illustration, wherein quenching the rolled aluminum alloy product comprises a forced air quenching process.
Illustration 22 is the method of any previous or subsequent illustration, further comprising aging the heat-treated aluminum alloy product to a T6 temper or a T7 temper.
Illustration 23 is the method of any previous or subsequent illustration, further comprising heating the heat-treated aluminum alloy product to a temperature from 100° C. to 170° C. and maintaining at the temperature for 12 hours to 30 hours.
Illustration 24 is the method of any previous or subsequent illustration, wherein the heat-treated aluminum alloy product exhibits an ultimate tensile strength of from 500 MPa to 650 MPa.
Illustration 25 is the method of any previous or subsequent illustration, wherein the heat-treated aluminum alloy product exhibits an ultimate tensile strength of from 605 MPa to 615 MPa when the quench rate is about 125° C./s.
Illustration 26 is the method of any previous or subsequent illustration, wherein the heat-treated aluminum alloy product exhibits a yield strength of from 400 MPa to 600 MPa.
Illustration 27 is the method of any previous or subsequent illustration, wherein the heat-treated aluminum alloy product exhibits a yield strength of from 560 MPa to 580 MPa when the quench rate is about 125° C./s.
Illustration 28 is the method of any previous or subsequent illustration, wherein the heat-treated aluminum alloy product exhibits a uniform elongation of from 7.50% to 10.50%.
Illustration 29 is the method of any previous or subsequent illustration, wherein the heat-treated aluminum alloy product exhibits a uniform elongation of from 9.00% to 9.60% when the quench rate is about 125° C./s.
Illustration 30 is the method of any previous or subsequent illustration, wherein the heat-treated aluminum alloy product exhibits a total elongation of from 10.00% to 15.00%.
Illustration 31 is the method of any previous or subsequent illustration, wherein the heat-treated aluminum alloy product exhibits a total elongation of from 13.80% to 14.20% when the quench rate is about 125° C./s.
Illustration 32 is the method of any previous or subsequent illustration, wherein the heat-treated aluminum alloy product exhibits a strain ratio of from 0.375 to 0.425 when the quench rate is about 125° C./s.
Illustration 33 is the method of any previous or subsequent illustration, where the heat-treated aluminum alloy product exhibits precipitate-free zone widths from 10 nm to 110 nm.
Illustration 34 is the method of any previous or subsequent illustration, where the heat-treated aluminum alloy product exhibits precipitate-free zone widths from 10 nm to 13 nm when the quench rate is about 125° C./s.
Illustration 35 is a product comprising: a heat-treated aluminum alloy, wherein the heat-treated aluminum alloy is a rolled 7xxx series aluminum alloy product comprising: from 4.00 wt. % to 15.00 wt. % Zn, from 0.10 wt. % to 3.50 wt. % Cu, from 1.00 wt. % to 4.00 wt. % Mg, from 0.05 wt. % to 0.50 wt. % Fe, from 0.05 wt. % to 0.30 wt. % Si, from 0.05 wt. % to 0.25 wt. % Zr, up to 0.25 wt. % Mn, up to 0.20 wt. % Cr, up to 0.15 wt. % Ti, up to 0.15 wt. % of impurities, and Al, and exhibiting a strain ratio of from 0.3 to 0.8, wherein the strain ratio is determined according to an ASTM G129 and/or an ASTM G139 standard test method.
Illustration 36 is the product of any previous or subsequent illustration, wherein the rolled 7xxx series aluminum alloy product exhibits a corrosion depth of from 5 μm to 300 μm as determined according to an ASTM G110 standard test method.
Illustration 37 is the product of any previous or subsequent illustration, wherein the rolled 7xxx series aluminum alloy product exhibits a corrosion depth of from 25 μm to 50 μm when a quench rate is 125° C./s.
Illustration 38 is the product of any previous or subsequent illustration, wherein the rolled 7xxx series aluminum alloy product is a formed aluminum alloy product.
Illustration 39 is the product of any previous or subsequent illustration, wherein the rolled 7xxx series aluminum alloy product is a hot formed aluminum alloy product.
Illustration 40 is the product of any previous or subsequent illustration, wherein the rolled 7xxx series aluminum alloy product to a T6 temper or a T7 temper.
Illustration 41 is the product of any previous or subsequent illustration, wherein the rolled 7xxx series aluminum alloy product exhibits an ultimate tensile strength of from 500 MPa to 650 MPa.
Illustration 42 is the product of any previous or subsequent illustration, wherein the rolled 7xxx series aluminum alloy product exhibits an ultimate tensile strength of from 605 MPa to 615 MPa when a quench rate is 125° C./s.
Illustration 43 is the product of any previous or subsequent illustration, wherein the rolled 7xxx series aluminum alloy product exhibits a yield strength of from 400 MPa to 600 MPa.
Illustration 44 is the product of any previous or subsequent illustration, wherein the rolled 7xxx series aluminum alloy product exhibits a yield strength of from 560 MPa to 580 MPa when a quench rate is 125° C./s.
Illustration 45 is the product of any previous or subsequent illustration, wherein the rolled 7xxx series aluminum alloy product exhibits a uniform elongation of from 7.50% to 10.50%.
Illustration 46 is the product of any previous or subsequent illustration, wherein the rolled 7xxx series aluminum alloy product exhibits a uniform elongation of from 9.00% to 9.60% when a quench rate is 125° C./s.
Illustration 47 is the product of any previous or subsequent illustration, wherein the rolled 7xxx series aluminum alloy product exhibits a total elongation of from 10.00% to 15.00%.
Illustration 48 is the product of any previous or subsequent illustration, wherein the rolled 7xxx series aluminum alloy product exhibits a total elongation of from 13.80% to 14.20% when a quench rate is 125° C./s.
Illustration 49 is the product of any previous or subsequent illustration, wherein the rolled 7xxx series aluminum alloy product exhibits a strain ratio of from 0.375 to 0.425 when a quench rate is 125° C./s.
Illustration 50 is the product of any previous or subsequent illustration, wherein the rolled 7xxx series aluminum alloy product exhibits precipitate-free zone widths from 10 nm to 110 nm.
Illustration 51 is the product of any previous or subsequent illustration, wherein the rolled 7xxx series aluminum alloy product exhibits precipitate-free zone widths from 10 nm to 13 nm when a quench rate is about 125° C./s.
Illustration 52 is the product of any previous or subsequent illustration, wherein the rolled 7xxx series aluminum alloy product is generated by: heating a rolled aluminum alloy product to a first temperature, wherein the rolled aluminum alloy product comprises a 7xxx series aluminum alloy, and wherein the first temperature is from 400° C. to 525° C.; maintaining the rolled aluminum alloy product at the first temperature or within 10° C. of the first temperature for a time duration of from 15 seconds to 30 minutes; and quenching the rolled aluminum alloy product at a quench rate from 0.5° C./s to 125° C./s.
Illustration 53 is the product of any previous or subsequent illustration, generated according to the method of any previous or subsequent illustration.
Illustration 54 is an automotive product incorporating the product of any previous or subsequent illustration.
Illustration 55 is an aerospace product incorporating the product of any previous or subsequent illustration.
Illustration 56 is an automotive product incorporating a product generated according to the method of any previous or subsequent illustration.
Illustration 57 is an aerospace product incorporating a product generated according to the method of any previous or subsequent illustration.
All patents, publications and abstracts cited above are incorporated herein by reference in their entirety. The foregoing description of the embodiments, including illustrated embodiments, has been presented only for the purpose of illustration and description and is not intended to be exhaustive or limiting to the precise forms disclosed. Numerous modifications, adaptations, and uses thereof will be apparent to those skilled in the art.
This application claims the benefit of and priority to U.S. Provisional Application No. 62/706,906, filed Sep. 17, 2020, which is hereby incorporated by reference in its entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2021/050709 | 9/16/2021 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 62706906 | Sep 2020 | US |
