Patent Application
20190376165
Provided herein are novel aluminum alloy compositions and methods of making and processing the same. In some cases, the alloys described herein can be used in bottle making applications and exhibit enhanced runnability, formability, and appearance.
Many modern methods of aluminum can or bottle manufacture require highly shapeable aluminum alloys. For shaped bottles, the manufacturing process typically involves first producing a cylinder using a drawing and wall ironing (DWI) process. The resulting cylinder is then formed into a bottle shape using, for example, a sequence of necking steps, blow molding, or other mechanical shaping, or a combination of these processes. The demands on any alloy used in such a process or combination of processes are complex.
Conventional alloy compositions and methods can have a poor defect rate for bottle manufacturing, for example due to denting in the neck of the bottle. Therefore, new alloys that can meet the demands of bottle manufacturing with a good overall defect rate and specifically minimum denting defect are needed. These alloys need to provide for aluminum bottle making with good runnability, formability, and appearance.
Covered examples of the invention are defined by the claims, not this summary. This summary is a high-level overview of various aspects of the invention 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, any or all drawings, and each claim.
Provided herein are novel aluminum alloy chemical compositions which in some examples can offer good defect rate, good earing, and/or minimum denting defect. In some cases, the alloys can be used in aluminum bottle making with good runnability, formability, and appearance.
In some examples, the aluminum alloys described herein comprise about 0.2-0.8 wt. % Fe, 0.05-0.50 wt. % Si, 0.40-1.65 wt. % Mg, 0.40-1.50 wt. % Mn, 0.03-0.35 wt. % Cu, up to 0.2 wt. % Cr, up to 0.2 wt. % Ni, up to 0.2 wt. % Ti, up to 1.0 wt. % of Zn, up to 0.2 wt. % Zr, up to 0.15 wt. % impurities, with the remainder as Al. In some examples, the aluminum alloys can have a ratio of Fe to Si of about 0.5 to 7.0. In some examples, the aluminum alloys can include an Effective Mg Index up to and including 0.9. Throughout this application, all elements are described in weight percentage (wt. %) based on the total weight of the alloy.
In some cases, the aluminum alloys described herein comprise about 0.3-0.6 wt. % Fe, 0.12-0.36 wt. % Si, 0.65-1.22 wt. % Mg, 0.65-1.1 wt. % Mn, 0.05-0.25 wt. % Cu, up to 0.1 wt. % Cr, up to 0.1 wt. % Ni, up to 0.1 wt. % Ti, up to 0.5 wt. % of Zn, up to 0.15 wt. % Zr, up to 0.15 wt. % impurities, with the remainder as Al. In some examples, the aluminum alloys can include a ratio of Fe to Si of 0.8 to 5. In some examples, the aluminum alloys can include an Effective Mg Index up to and including 0.9, for example, up to and including 0.87.
In some cases, the aluminum alloy comprises about 0.36-0.44 wt. % Fe, 0.21-0.27 wt. % Si, 0.75-0.85 wt. % Mg, 0.75-0.85 wt. % Mn, 0.11-0.15 wt. % Cu, up to 0.05 wt. % Cr, up to 0.03 wt. % Ni, up to 0.05 wt. % Ti, up to 0.25 wt. % of Zn, up to 0.03 wt. % Zr, up to 0.15 wt. % impurities, with the remainder as Al. In some examples, the aluminum alloys can include a ratio of Fe to Si of 1.3 to 2.1. In some examples, the aluminum alloys can include an Effective Mg Index up to and including 0.9 or 0.75.
In some cases, the aluminum alloy comprises about 0.36-0.44 wt. % Fe, 0.21-0.27 wt. % Si, 0.75-0.85 wt. % Mg, 0.75-0.85 wt. % Mn, 0.06-0.1 wt. % Cu, up to 0.05 wt. % Cr, up to 0.03 wt. % Ni, up to 0.05 wt. % Ti, up to 0.25 wt. % of Zn, up to 0.03 wt. % Zr, up to 0.15 wt. % impurities, with the remainder as Al. In some examples, the aluminum alloys can include a ratio of Fe to Si of 1.3 to 2.1. In some examples, the aluminum alloys can include an Effective Mg Index up to and including 0.9 or 0.77.
In some cases, the aluminum alloy comprises about 0.36-0.44 wt. % Fe, 0.15-0.21 wt. % Si, 0.75-0.85 wt. % Mg, 0.75-0.85 wt. % Mn, 0.11-0.15 wt. % Cu, up to 0.05 wt. % Cr, up to 0.03 wt. % Ni, up to 0.05 wt. % Ti, up to 0.25 wt. % of Zn, up to 0.03 wt. % Zr, up 0.15 wt. % impurities, with the remainder as Al. In some examples, the aluminum alloys can include a ratio of Fe to Si of 1.7 to 2.9. In some examples, the aluminum alloys can include an Effective Mg Index up to and including 0.9 or 0.8.
In some cases, the aluminum alloy comprises about 0.36-0.44 wt. % Fe, 0.21-0.27 wt. % Si, 0.75-0.85 wt. % Mg, 0.75-0.85 wt. % Mn, 0.18-0.22 wt. % Cu, up to 0.05 wt. % Cr, up to 0.03 wt. % Ni, up to 0.05 wt. % Ti, up to 0.25 wt. % of Zn, up to 0.03 wt. % Zr, up 0.15 wt. % impurities, with the remainder as Al. In some examples, the aluminum alloys can include a ratio of Fe to Si of 1.3 to 2.1. In some examples, the aluminum alloys can include an Effective Mg Index up to and including 0.9 or 0.73.
In some cases, the aluminum alloy comprises about 0.46-0.54 wt. % Fe, 0.27-0.33 wt. % Si, 0.93-1.07 wt. % Mg, 0.8-0.94 wt. % Mn, 0.11-0.15 wt. % Cu, up to 0.05 wt. % Cr, up to 0.03 wt. % Ni, up to 0.05 wt. % Ti, up to 0.25 wt. % of Zn, up to 0.03 wt. % Zr, up to 0.15 wt. % impurities, with the remainder as Al. In some examples, the aluminum alloys can include a ratio of Fe to Si of 1.4 to 2.0. In some examples, the aluminum alloys can include an Effective Mg Index up to and including 0.9, 0.88, or 0.75.
Also provided herein are products comprising the aluminum alloys as described herein. The products can include a sheet, a plate, an extrusion, a casting, or a forging. In some examples, the product is a bottle or can. In some examples, the product can have an average dislocation cell size below 500 nm, for example, in some cases, below 300 nm. In some examples, the product can have a geometrically necessary boundary spacing distance of less than 1.6 μm.
Also described herein are methods of producing a metal product. The methods of producing the metal product include, but are not limited to, the steps of casting an aluminum alloy as described herein to form an ingot or a slab, homogenizing the ingot or the slab, hot rolling the ingot or the slab to form an aluminum alloy body (e.g., a coil, plate, shate, sheet, foil, slab or other product after being hot rolled), and cold rolling the aluminum alloy body to a metal product of final gauge. In some examples, the homogenizing step includes subjecting the ingot or slab to a temperature of from about 550° C. to about 625° C. for between 2 to 30 hours. For the avoidance of doubt, the homogenizing step refers to a period in which the ingot or slab is at a peak metal temperature (“PMT”). In some examples, a two-step homogenization is performed where a prepared ingot is heated to attain a first temperature and allowed to soak for a period of time. In the second stage, the ingot can be cooled to a temperature lower than the temperature used in the first stage and allowed to soak for a period of time during the second stage. For example, a prepared ingot may be heated from about 300° C. over a 5 hour ramp period to a PMT temperature of approximately 580° C. to approximately 610° C. and allowed to soak for approximately 4 hours at the PMT temperature. In the second stage, the ingot may be cooled to a second temperature of about 540° C. to about 560° C. and allowed to soak for approximately 3 hours during the second stage.
In some cases, the hot rolling comprises a two-stage process that includes processing an ingot on a single stand breakdown mill and then processing a slab on a hot finishing mill to produce the aluminum body or coil. In some cases, the entry temperature for the breakdown mill, also known as the ingot laydown temperature, is from about 480° C. to about 600° C. Upon exiting the breakdown mill, the slab can be at a second temperature (also referred to as the slab transfer temperature) of about 400° C. to about 470° C., and then fed to a hot finishing mill. In some examples, the exit temperature for the hot rolling step (after the hot finishing mill) is from about 280° C. to about 400° C. In some cases, the hot rolling exit temperature is greater than the recrystallization temperature of the alloy.
In some examples, the cold rolling step includes reducing the aluminum alloy body by about 60% to about 99% thickness reduction. In some cases, the cold rolling step can include a plurality of cold rolling operations, for example, one, two, three, four, or more cold rolling operations.
In some examples, the methods described herein can optionally include an annealing step after the hot rolling step (and before the cold rolling step). In some examples, the optional annealing step includes self-annealing. In some such examples, the annealing step can include subjecting the aluminum alloy body (e.g., a hot rolled coil) to a PMT from about 280° C. to about 480° C. for between about 0.5 hours to about 10 hours. In some examples, the methods described herein can optionally include a partial annealing step after the cold rolling step. In some such examples, the partial annealing step can include subjecting the metal product (e.g., a cold rolled coil) to a PMT from about 100° C. to about 300° C. for between about 0.5 hours to about 4 hours.
In some cases, the methods described herein can produce an aluminum sheet. In some examples, the methods can be used to make bottles or cans from the sheet.
Other objects and advantages of the invention will be apparent from the following detailed description of non-limiting examples of the invention.
The terms “invention,” “the invention,” “this invention” and “the present invention” used herein 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.” 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, the meaning of “a,” “an,” and “the” includes singular and plural references unless the context clearly dictates otherwise.
Aluminum alloys are described herein 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.
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, 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 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, or 15 mm.
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 4 mm, less than 3 mm, less than 2 mm, less than 1 mm, less than 0.5 mm, less than 0.3 mm, or less than 0.1 mm.
As used herein, terms such as “cast product,” “cast aluminum alloy,” “cast aluminum alloy product,” and the like are interchangeable and refer to a product produced by direct chill casting (including direct chill co-casting) or semi-continuous casting, continuous casting (including, for example, by use of a twin belt caster, a twin roll caster, a block caster, or any other continuous caster), electromagnetic casting, hot top casting, or any other casting method.
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.
Provided herein are novel aluminum alloy chemical compositions which when made according to the processes described herein can in some cases offer aluminum bottle making with minimum defect rate (e.g., due to fracture or denting during forming) and good earing. The alloys can offer aluminum bottle making with good runnability, formability, and appearance.
Table 1 shows exemplary alloys made according to the processes described herein that may offer good defect rates due to fracture, good earing, and minimum denting defects.
In some examples, the alloy can have the following elemental composition as provided in Table 2.
In some examples, the alloy can have the following elemental composition as provided in Table 3.
In some examples, the alloy can have the following elemental composition as provided in Table 4.
In some examples, the alloy can have the following elemental composition as provided in Table 5.
In some examples, the alloy can have the following elemental composition as provided in Table 6.
In some examples, the alloys described herein include iron (Fe) in an amount of from 0.2% to 0.8% (e.g., from 0.3% to 0.6%, from 0.36% to 0.44%, or from 0.46% to 0.54%) based on the total weight of the alloy. For example, the alloy can include 0.2%, 0.21%, 0.22%, 0.23%, 0.24%, 0.25%, 0.26%, 0.27%, 0.28%, 0.29%, 0.3%, 0.31%, 0.32%, 0.33%, 0.34%, 0.35%, 0.36%, 0.37%, 0.38%, 0.39%, 0.4%, 0.41%, 0.42%, 0.43%, 0.44%, 0.45%, 0.46%, 0.47%, 0.48%, 0.49%, 0.5%, 0.51%, 0.52%, 0.53%, 0.54%, 0.55%, 0.56%, 0.57%, 0.58%, 0.59%, 6%, 0.61%, 0.62%, 0.63%, 0.64%, 0.65%, 0.66%, 0.67%, 0.68%, 0.69%, 0.7%, 0.71%, 0.72%, 0.73%, 0.74%, 0.75%, 0.76%, 0.77%, 0.78%, 0.79%, or 0.8% Fe. All are expressed in wt. %.
In some examples, the alloys described include silicon (Si) in an amount of from 0.05% to 0.50% (e.g., from 0.12% to 0.36%, from 0.21% to 0.27%, from 0.15% to 0.21%, or from 0.27% to 0.33%) based on the total weight of the alloy. For example, the alloy can include 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, 0.2%, 0.21%, 0.22%, 0.23%, 0.24%, 0.25%, 0.26%, 0.27%, 0.28%, 0.29%, 0.3%, 0.31%, 0.32%, 0.33%, 0.34%, 0.35%, 0.36%, 0.37%, 0.38%, 0.39%, 0.4, 0.41%, 0.42%, 0.43%, 0.44%, 0.45%, 0.46%, 0.47%, 0.48%, 0.49%, or 0.50% Si. All are expressed in wt. %.
In some examples, the alloys described herein include magnesium (Mg) in an amount of from 0.40% to 1.65% (e.g., from 0.65% to 1.22%, from 0.75% to 0.85%, or from 0.93% to 1.07%). In some cases, the alloy can include 0.4%, 0.41%, 0.42%, 0.43%, 0.44%, 0.45%, 0.46%, 0.47%, 0.48%, 0.49%, 0.5%, 0.51%, 0.52%, 0.53%, 0.54%, 0.55%, 0.56%, 0.57%, 0.58%, 0.59%, 0.6%, 0.61%, 0.62%, 0.63%, 0.64%, 0.65%, 0.66%, 0.67%, 0.68%, 0.69%, 0.7%, 0.71%, 0.72%, 0.73%, 0.74%, 0.75%, 0.76%, 0.77%, 0.78%, 0.79%, 0.8%, 0.81%, 0.82%, 0.83%, 0.84%, 0.85%, 0.86%, 0.87%, 0.88%, 0.89%, 0.9%, 0.91%, 0.92%, 0.93%, 0.94%, 0.95%, 0.96%, 0.97%, 0.98%, 0.99%, 1.0%, 1.01%, 1.02%, 1.03%, 1.04%, 1.05%, 1.06%, 1.07%, 1.08%, 1.09%, 1.10%, 1.11%, 1.12%, 1.13%, 1.14%, 1.15%, 1.16%, 1.17%, 1.18%, 1.19%, 1.2%, 1.21%, 1.22%, 1.23%, 1.24%, 1.25%, 1.26%, 1.27%, 1.28%, 1.29%, 1.3%, 1.31%, 1.32%, 1.33%, 1.34%, 1.35%, 1.36%, 1.37%, 1.38%, 1.39%, 1.4%, 1.41%, 1.42%, 1.43%, 1.44%, 1.45%, 1.46%, 1.47%, 1.48%, 1.49%, 1.5%, 1.51%, 1.52%, 1.53%, 1.54%, 1.55%, 1.56%, 1.57%, 1.58%, 1.59%, 1.6%, 1.61%, 1.62%, 1.63%, 1.64%, or 1.65% Mg. All are expressed in wt. %. In some examples, Mg can be reduced to relatively low levels to reduce work hardening and defect rate during bottle necking process. In some cases, lower Mg levels can promote more cube texture formation in the hot band and thus more cube texture is retained in final gauge to offer a more balanced earing profile with high cold rolling reduction. The lower Mg level can also lead to less shear-type texture, such as cube rotated around the rolling direction (Cube_RD), during hot rolling, which reduces the propensity of denting formation. Texture components such as Cube_RD lying in the beta fiber for the sheet can be transformed during the drawing and wall ironing (DWI) process into Goss texture in the top thin wall of the preform at the south-east location. This transformation may then result in metal flow incompatibility during die-necking at the south-east locations where the dents are usually formed, as shown in
In some examples, the alloys described herein include manganese (Mn) in an amount of from 0.40% to 1.50% (e.g., from 0.65% to 1.1%, from 0.75% to 0.85%, or from 0.8% to 0.94%). In some cases, the alloy can include 0.4%, 0.41%, 0.42%, 0.43%, 0.44%, 0.45%, 0.46%, 0.47%, 0.48%, 0.49%, 0.5%, 0.51%, 0.52%, 0.53%, 0.54%, 0.55%, 0.56%, 0.57%, 0.58%, 0.59%, 0.6%, 0.61%, 0.62%, 0.63%, 0.64%, 0.65%, 0.66%, 0.67%, 0.68%, 0.69%, 0.7%, 0.71%, 0.72%, 0.73%, 0.74%, 0.75%, 0.76%, 0.77%, 0.78%, 0.79%, 0.8%, 0.81%, 0.82%, 0.83%, 0.84%, 0.85%, 0.86%, 0.87%, 0.88%, 0.89%, 0.90%, 0.91%, 0.92%, 0.93%, 0.94%, 0.95%, 0.96%, 0.97%, 0.98%, 0.99%, 1.0%, 1.01%, 1.02%, 1.03%, 1.04%, 1.05%, 1.06%, 1.07%, 1.08%, 1.09%, 1.10%, 1.11%, 1.12%, 1.13%, 1.14%, 1.15%, 1.16%, 1.17%, 1.18%, 1.19%, 1.2%, 1.21%, 1.22% 1.23%, 1.24%, 1.25%, 1.26%, 1.27%, 1.28%, 1.29%, 1.3%, 1.31%, 1.32%, 1.33%, 1.34%, 1.35%, 1.36%, 1.37%, 1.38%, 1.39%, 1.4%, 1.41%, 1.42%, 1.43%, 1.44%, 1.45%, 1.46%, 1.47%, 1.48%, 1.49%, or 1.50% Mn. All are expressed in wt. %. In some examples, Mn can be included at a relatively low level to reduce work hardening of the material for better defect performance, e.g., from splitting during curling.
In some examples, the alloys described herein include copper (Cu) in an amount of from 0.03% to 0.35% (e.g., from 0.03% to 0.33%, from 0.11% to 0.15%, from 0.06% to 0.1%, or from 0.18% to 0.22%). In some cases, the alloy can include 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, 0.2%, 0.21%, 0.22%, 0.23%, 0.24%, 0.25%, 0.26%, 0.27%, 0.28%, 0.29%, 0.3%, 0.31%, 0.32%, 0.33%, 0.34%, or 0.35% Cu. All are expressed in wt. %. In some examples, the concentration of Cu can be reduced to a relatively low level within the ranges described herein to reduce work hardening and the defect rate during the bottle necking process as well as to reduce shear texture formation during the hot rolling process. The reduced localized shearing during hot rolling can promote more cube texture formation in the hot band and allow more cube texture to be retained at final gauge to offer improved earing. The lower Cu level can lead to less shear-type texture, including beta-fiber formation, during hot rolling, which reduces the propensity for dent formation. In other examples, the Cu level can be increased to a relatively high level within the ranges described herein to form over-aged S phase precipitates through the final annealing process. These incoherent S phase precipitates reduce the localized strain during cold forming, which can improve the strain accommodation.
In some examples, the ratio of Fe to Si may range from 0.5 to 7.0 (e.g., from 0.8 to 5, from 1.3 to 2.1, from 1.7 to 2.9, or from 1.4 to 2). For example, the ratio of Fe to Si can be 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, 6, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, or 7.0. In some examples, the concentration of Fe and Si can be designed to a relatively low level to maximize the formation of cube texture component in hot band by minimizing particle stimulated nucleation (PSN) effects. In some cases, the Fe to Si ratio can be designed to be relatively high to reduce PSN and promote cube texture in the hot band. In some examples, the composition and ratio can maximize the cube texture component in final gauge and thus reduce mean earing to reach a more balanced earing profile when cold rolling reduction is high.
In some examples, the alloys described herein include chromium (Cr) in an amount of up to 0.2% based on the total weight of the alloy. For example, the alloy can include 0.01%, 0.011%, 0.012%, 0.013%, 0.014%, 0.015%, 0.016%, 0.017%, 0.018%, 0.019%, 0.02%, 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%, 0.051%, 0.052%, 0.053%, 0.054%, 0.055%, 0.056%, 0.057%, 0.058%, 0.059%, 0.06%, 0.061%, 0.062%, 0.063%, 0.064%, 0.065%, 0.066%, 0.067%, 0.068%, 0.069%, 0.07%, 0.071%, 0.072%, 0.073%, 0.074%, 0.075%, 0.076%, 0.077%, 0.078%, 0.079%, 0.08%, 0.081%, 0.082%, 0.083%, 0.084%, 0.085%, 0.086%, 0.087%, 0.088%, 0.089%, 0.09%, 0.091%, 0.092%, 0.093%, 0.094%, 0.095%, 0.096%, 0.097%, 0.098%, 0.099%, 0.1%, 0.101%, 0.102%, 0.103%, 0.104%, 0.105%, 0.106%, 0.107%, 0.108%, 0.109%, 0.11%, 0.111%, 0.112%, 0.113%, 0.114%, 0.115%, 0.116%, 0.117%, 0.118%, 0.119%, 0.12%, 0.121%, 0.122%, 0.123%, 0.124%, 0.125%, 0.126%, 0.127%, 0.128%, 0.129%, 0.13%, 0.131%, 0.132%, 0.133%, 0.134%, 0.135%, 0.136%, 0.137%, 0.138%, 0.139%, 0.14%, 0.141%, 0.142%, 0.143%, 0.144%, 0.145%, 0.146%, 0.147%, 0.148%, 0.149%, 0.15%, 0.151%, 0.152%, 0.153%, 0.154%, 0.155%, 0.156%, 0.157%, 0.158%, 0.159%, 0.16%, 0.161%, 0.162%, 0.163%, 0.164%, 0.165%, 0.166%, 0.167%, 0.168%, 0.169%, 0.17%, 0.171%, 0.172%, 0.173%, 0.174%, 0.175%, 0.176%, 0.177%, 0.178%, 0.179%, 0.18%, 0.181%, 0.182%, 0.183%, 0.184%, 0.185%, 0.186%, 0.187%, 0.188%, 0.189%, 0.19%, 0.191%, 0.192%, 0.193%, 0.194%, 0.195%, 0.196%, 0.197%, 0.198%, 0.199%, or 0.2% Cr. In some cases, Cr is not present in the alloy (i.e., 0%). All are expressed in wt. %.
In some examples, the alloys described herein include nickel (Ni) in an amount of up to 0.2% based on the total weight of the alloy. For example, the alloy can include 0.010%, 0.011%, 0.012%, 0.013%, 0.014%, 0.015%, 0.016%, 0.017%, 0.018%, 0.019%, 0.02%, 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%, 0.051%, 0.052%, 0.053%, 0.054%, 0.055%, 0.056%, 0.057%, 0.058%, 0.059%, 0.06%, 0.061%, 0.062%, 0.063%, 0.064%, 0.065%, 0.066%, 0.067%, 0.068%, 0.069%, 0.07%, 0.071%, 0.072%, 0.073%, 0.074%, 0.075%, 0.076%, 0.077%, 0.078%, 0.079%, 0.08%, 0.081%, 0.082%, 0.083%, 0.084%, 0.085%, 0.086%, 0.087%, 0.088%, 0.089%, 0.09%, 0.091%, 0.092%, 0.093%, 0.094%, 0.095%, 0.096%, 0.097%, 0.098%, 0.099%, 0.1%, 0.101%, 0.102%, 0.103%, 0.104%, 0.105%, 0.106%, 0.107%, 0.108%, 0.109%, 0.11%, 0.111%, 0.112%, 0.113%, 0.114%, 0.115%, 0.116%, 0.117%, 0.118%, 0.119%, 0.12%, 0.121%, 0.122%, 0.123%, 0.124%, 0.125%, 0.126%, 0.127%, 0.128%, 0.129%, 0.13%, 0.131%, 0.132%, 0.133%, 0.134%, 0.135%, 0.136%, 0.137%, 0.138%, 0.139%, 0.14%, 0.141%, 0.142%, 0.143%, 0.144%, 0.145%, 0.146%, 0.147%, 0.148%, 0.149%, 0.15%, 0.151%, 0.152%, 0.153%, 0.154%, 0.155%, 0.156%, 0.157%, 0.158%, 0.159%, 0.16%, 0.161%, 0.162%, 0.163%, 0.164%, 0.165%, 0.166%, 0.167%, 0.168%, 0.169%, 0.17%, 0.171%, 0.172%, 0.173%, 0.174%, 0.175%, 0.176%, 0.177%, 0.178%, 0.179%, 0.18%, 0.181%, 0.182%, 0.183%, 0.184%, 0.185%, 0.186%, 0.187%, 0.188%, 0.189%, 0.19%, 0.191%, 0.192%, 0.193%, 0.194%, 0.195%, 0.196%, 0.197%, 0.198%, 0.199%, or 0.2% Ni. In some cases, Ni is not present in the alloy (i.e., 0%). All are expressed in wt. %.
In some examples, the alloys described herein include titanium (Ti) in an amount of up to 0.2% based on the total weight of the alloy. For example, the alloy can include 0.01%, 0.011%, 0.012%, 0.013%, 0.014%, 0.015%, 0.016%, 0.017%, 0.018%, 0.019%, 0.02%, 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%, 0.051%, 0.052%, 0.053%, 0.054%, 0.055%, 0.056%, 0.057%, 0.058%, 0.059%, 0.06%, 0.061%, 0.062%, 0.063%, 0.064%, 0.065%, 0.066%, 0.067%, 0.068%, 0.069%, 0.07%, 0.071%, 0.072%, 0.073%, 0.074%, 0.075%, 0.076%, 0.077%, 0.078%, 0.079%, 0.08%, 0.081%, 0.082%, 0.083%, 0.084%, 0.085%, 0.086%, 0.087%, 0.088%, 0.089%, 0.09%, 0.091%, 0.092%, 0.093%, 0.094%, 0.095%, 0.096%, 0.097%, 0.098%, 0.099%, 0.1%, 0.101%, 0.102%, 0.103%, 0.104%, 0.105%, 0.106%, 0.107%, 0.108%, 0.109%, 0.11%, 0.111%, 0.112%, 0.113%, 0.114%, 0.115%, 0.116%, 0.117%, 0.118%, 0.119%, 0.12%, 0.121%, 0.122%, 0.123%, 0.124%, 0.125%, 0.126%, 0.127%, 0.128%, 0.129%, 0.13%, 0.131%, 0.132%, 0.133%, 0.134%, 0.135%, 0.136%, 0.137%, 0.138%, 0.139%, 0.14%, 0.141%, 0.142%, 0.143%, 0.144%, 0.145%, 0.146%, 0.147%, 0.148%, 0.149%, 0.15%, 0.151%, 0.152%, 0.153%, 0.154%, 0.155%, 0.156%, 0.157%, 0.158%, 0.159%, 0.16%, 0.161%, 0.162%, 0.163%, 0.164%, 0.165%, 0.166%, 0.167%, 0.168%, 0.169%, 0.17%, 0.171%, 0.172%, 0.173%, 0.174%, 0.175%, 0.176%, 0.177%, 0.178%, 0.179%, 0.18%, 0.181%, 0.182%, 0.183%, 0.184%, 0.185%, 0.186%, 0.187%, 0.188%, 0.189%, 0.19%, 0.191%, 0.192%, 0.193%, 0.194%, 0.195%, 0.196%, 0.197%, 0.198%, 0.199%, or 0.2% Ti. In some cases, Ti is not present in the alloy (i.e., 0%). All are expressed in wt. %.
In some examples, the alloys described herein include zinc (Zn) in an amount of up to 1% based on the total weight of the alloy. For example, the alloy can include 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, 0.2%, 0.21%, 0.22%, 0.23%, 0.24%, 0.25%, 0.26%, 0.27%, 0.28%, 0.29%, 0.3%, 0.31%, 0.32%, 0.33%, 0.34%, 0.35%, 0.36%, 0.37%, 0.38%, 0.39%, 0.4%, 0.41%, 0.42%, 0.43%, 0.44%, 0.45%, 0.46%, 0.47%, 0.48%, 0.49%, 0.5%, 0.51%, 0.52%, 0.53%, 0.54%, 0.55%, 0.56%, 0.57%, 0.58%, 0.59%, 0.6%, 0.61%, 0.62%, 0.63%, 0.64%, 0.65%, 0.66%, 0.67%, 0.68%, 0.69%, 0.7%, 0.71%, 0.72%, 0.73%, 0.74%, 0.75%, 0.76%, 0.77%, 0.78%, 0.79%, 0.8%, 0.81%, 0.82%, 0.83%, 0.84%, 0.85%, 0.86%, 0.87%, 0.88%, 0.89%, 0.9%, 0.91%, 0.92%, 0.93%, 0.94%, 0.95%, 0.96%, 0.97%, 0.98%, 0.99%, or 1.0% Zn. In some cases, Zn is not present in the alloy (i.e., 0%). All are expressed in wt. %.
In some examples, the alloys described herein include zirconium (Zr) in an amount of up to 0.2% based on the total weight of the alloy. For example, the alloy can include 0.01%, 0.011%, 0.012%, 0.013%, 0.014%, 0.015%, 0.016%, 0.017%, 0.018%, 0.019%, 0.02%, 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%, 0.051%, 0.052%, 0.053%, 0.054%, 0.055%, 0.056%, 0.057%, 0.058%, 0.059%, 0.06%, 0.061%, 0.062%, 0.063%, 0.064%, 0.065%, 0.066%, 0.067%, 0.068%, 0.069%, 0.07%, 0.071%, 0.072%, 0.073%, 0.074%, 0.075%, 0.076%, 0.077%, 0.078%, 0.079%, 0.08%, 0.081%, 0.082%, 0.083%, 0.084%, 0.085%, 0.086%, 0.087%, 0.088%, 0.089%, 0.09%, 0.091%, 0.092%, 0.093%, 0.094%, 0.095%, 0.096%, 0.097%, 0.098%, 0.099%, 0.1%, 0.101%, 0.102%, 0.103%, 0.104%, 0.105%, 0.106%, 0.107%, 0.108%, 0.109%, 0.11%, 0.111%, 0.112%, 0.113%, 0.114%, 0.115%, 0.116%, 0.117%, 0.118%, 0.119%, 0.12%, 0.121%, 0.122%, 0.123%, 0.124%, 0.125%, 0.126%, 0.127%, 0.128%, 0.129%, 0.13%, 0.131%, 0.132%, 0.133%, 0.134%, 0.135%, 0.136%, 0.137%, 0.138%, 0.139%, 0.14%, 0.141%, 0.142%, 0.143%, 0.144%, 0.145%, 0.146%, 0.147%, 0.148%, 0.149%, 0.15%, 0.151%, 0.152%, 0.153%, 0.154%, 0.155%, 0.156%, 0.157%, 0.158%, 0.159%, 0.16%, 0.161%, 0.162%, 0.163%, 0.164%, 0.165%, 0.166%, 0.167%, 0.168%, 0.169%, 0.17%, 0.171%, 0.172%, 0.173%, 0.174%, 0.175%, 0.176%, 0.177%, 0.178%, 0.179%, 0.18%, 0.181%, 0.182%, 0.183%, 0.184%, 0.185%, 0.186%, 0.187%, 0.188%, 0.189%, 0.19%, 0.191%, 0.192%, 0.193%, 0.194%, 0.195%, 0.196%, 0.197%, 0.198%, 0.199%, or 0.2% Zr. In other examples, the alloys can include Zr is not present in the alloy (i.e., 0%). All are expressed in wt. %.
Optionally, the alloy compositions described herein can further include other minor elements, sometimes referred to as impurities, in amounts of about 0.05% or below, about 0.04% or below, about 0.03% or below, about 0.02% or below, or about 0.01% or below each. The sum of all impurities does not exceed 0.15% (e.g., 0.10%). All expressed in wt. %. The remaining percentage of the alloy is aluminum.
Not to be bound by theory, a relationship may exist between the forms of Mg present in an alloy. Mg may exist in three major forms in an alloy: (1) in solid solution; (2) bonded with Si in magnesium silicide phase (Mg2Si); and (3) bonded with Cu and Al in S phase (Al2CuMg). This relationship may be quantified using an Effective Magnesium Index (Eff. Mg Index). The Eff. Mg Index may be used as an indicator of the amount of Mg in the solid solution of the alloy. The amount of Mg in the solid solution can contribute to the work hardening levels as reflected by the tensile spread (also referred to as the spread) of an alloy, which is the difference between the yield strength and ultimate tensile strength. The Eff. Mg Index is proportional to work hardening, i.e., the higher the Eff. Mg Index, the higher the work hardening. The Eff. Mg Index may be calculated according to the equation below, where the amounts of each element are all in units of wt. % of the element in a given alloy:
For example, an aluminum alloy with 0.85 wt. % Mg, 0.15 wt. % Cu, 0.27 wt. % Si, 0.44 wt. % Fe, 0.85 wt. % Mn, and 0.05 wt. % Cr would have an Eff. Mg Index of 0.75 as shown by the following equation:
In some examples, the alloys described herein include an Eff. Mg Index in an amount of up to and including 0.9. For example, the alloy can include an Eff. Mg Index of up to 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.2, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.3, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.4, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, 0.5, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.6, 0.61, 0.62, 0.63, 0.64, 0.65, 0.66, 0.67, 0.68, 0.69, 0.7, 0.71, 0.72, 0.73, 0.74, 0.75, 0.76, 0.77, 0.78, 0.79, 0.8, 0.81, 0.82, 0.83, 0.84, 0.85, 0.86, 0.87, 0.88, 0.89, or 0.9.
In some examples, the alloys described herein and those made according to methods described herein can provide high recyclability. The alloys can have moderate combinations of defect rate, earing, and denting performance. The alloys made according to methods described herein can provide additional improved properties and performance by modifying the composition as compared to a conventional alloy. For example, the levels of magnesium (Mg), copper (Cu), silicon (Si), and manganese (Mn), as compared to a conventional alloy, can be modified to achieve certain properties and characteristics, such as a targeted ratio of Fe to Si or Effective Mg Index. The processing conditions further described herein can provide additional improved properties and performance by modifying the temperature and timing of certain steps as compared to a conventional alloy. For example, the level of cold roll reduction as compared to a conventional alloy can be adjusted to achieve certain properties and characteristics, such as earing balance, mean earing, and geometrically necessary boundaries (GNB) spacing. In some examples, modifying both the composition and processing conditions as compared to a conventional alloy as described herein can provide additional improved properties and performance.
The alloys described herein can be cast into ingots using a direct chill (DC) process. Optionally, the casting process can include a continuous casting (CC) process. The continuous casting may include, but is not limited to, twin roll casters, twin belt casters, and block casters. In some cases, to achieve the desired microstructure, mechanical properties, and physical properties of the products, the alloys are not processed using continuous casting methods.
The cast product (e.g., cast coil or metal coil) can be subjected to further processing steps to form a metal sheet. In some examples, the further processing steps include subjecting a metal coil to a homogenization cycle, a hot rolling step, and a cold rolling step. In some examples, the further processing steps include subjecting a metal coil to a homogenization cycle, a hot rolling step, an optional annealing step, and a cold rolling step. In some examples, the further processing steps include subjecting a metal coil to a homogenization cycle, a hot rolling step, a cold rolling step, an optional annealing step, a second cold rolling step, and an optional partial annealing step. In some examples, the methods described herein can subject an alloy to thermo-mechanical processing that can provide certain microstructure properties and characteristics that provide an aluminum product that can be used in different applications, for example, used to make bottles.
In some examples, the homogenization step can involve a one-step homogenization or a two-step homogenization. In some examples, the homogenization step comprises heating a cast product (e.g., an ingot or a slab) prepared from the alloy compositions described herein is to a peak metal temperature (PMT). The cast product is then allowed to soak (i.e., held at the PMT temperature) for a period of time. In some examples, the homogenizing is performed at a temperature of 550° C. to 625° C. for up to 30 hours (e.g., 525° C. to 625° C. for a period of 2 hours to 30 hours or 535° C. to 615° C., 545° C. to 605° C., 555° C. to 595° C., 565° C. to 585° C., or 575° C. to 600° C. each for a period of 2 hours to 30 hours, or in some cases, each for a period of 2 hours to 15 hours).
In other examples, the homogenization step comprises a two-step homogenization. In some cases, the homogenization process can include the above-described heating and soaking steps, which can be referred to as the first stage, and can further include a second stage. In the second stage of the homogenization process, the cast product temperature can be decreased to a temperature lower than the temperature used for the first stage of the homogenization process. The cast product temperature can be decreased, for example, to a temperature at least five degrees Celsius lower than the PMT during the first stage of the homogenization process. For example, the cast product temperature can be decreased to a temperature of at least 540° C. (e.g., at least 550° C., at least 560° C., or at least 570° C.). The heating rate to the second stage homogenization temperature can be 5° C./hour or less, 3° C./hour or less, or 2.5° C./hour or less. The cast product is then allowed to soak for a period of time at the second temperature during the second stage. In some cases, the ingot is allowed to soak for up to 10 hours (e.g., from 30 minutes to 10 hours, inclusively). For example, the cast product can be soaked at the temperature of at least 550° C. for 30 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, or 10 hours. Following homogenization, the cast product can be allowed to cool to room temperature in the air. In describing the homogenization step temperatures, as appreciated by persons of skill in the art, the time required to ramp the ingot or slab to the homogenizing temperature may vary.
Following the homogenization step, a hot rolling process can be performed. The hot rolling speed, reduction, and temperature can be controlled such that full recrystallization of the hot rolled materials is achieved following coiling at the exit of the hot finishing mill. In some examples, the hot rolling temperature is greater than the recrystallization temperature of the alloy. In some cases, the hot rolling comprises a two-stage process that includes processing an ingot on a single stand breakdown mill and then processing a slab on a hot finishing mill to produce the aluminum alloy body or coil. In some cases, the entry temperature for the breakdown mill, also known as the ingot laydown temperature, is from about 480° C. to about 600° C. (e.g., 480° C. to 600° C., 490° C. to 590° C., 500° C. to 580° C., 510° C. to 570° C., 520° C. to 560° C., or 520° C. to 540° C.). In some cases, the ingot laydown temperature for the hot rolling operation is from about 500° C. to about 560° C. Upon exiting the breakdown mill, the slab can be at a second temperature (also referred to as the slab transfer temperature) of about 400° C. to about 470° C. and then fed to a hot finishing mill. The exit temperature for the hot rolling operation can be from about 280° C. to about 400° C. (e.g., 280° C. to 400° C., 290° C. to 390° C., 300° C. to 380° C., 310° C. to 370° C., 320° C. to 360° C., 330° C. to 350° C., or 340° C. to 360° C.). In some cases, the exit temperature for the hot rolling operation is from about 315° C. to about 360° C.
In some examples, the ingots or slabs can be hot rolled to a final gauge of a 10 mm thick gauge or less. For example, the ingots or slabs can be hot rolled to a 6.3 mm thick gauge or less, 5.2 mm thick gauge or less, 4.3 mm thick gauge or less, or 4 mm thick gauge or less. In some cases, the ingots or slabs can be hot rolled to a final gauge between about 4 mm to 6 mm thick gauge. In some examples, hot rolling produces a total reduction in thickness of from about 60% to 99% (e.g., about 65% to 95%, about 70% to 95%, about 75% to 95%, 80% to 95%, 85% to 95%, or 90% to 99%). For example, the hot rolling step produces a reduction in thickness of about 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%. The percent hot rolling, or % HR, is referred to in this context as the change in thickness due to hot rolling divided by the initial strip thickness prior to hot rolling. As described above, the hot rolling can be conducted in several individual hot rolling steps, for example, using a breakdown mill, a hot finishing mill, and/or a reversing mill. In some examples, the hot rolled products can be rolled to an intermediate gauge thickness. In some such cases, the intermediate gauge thickness can correspond to a reduction in thickness of about 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95, %, 96%, or 97%. In some examples, the first stage of the hot rolling process can provide a reduction in the range of 94.0% to 96.0%. The second stage of the hot rolling process can further reduce the thickness of the aluminum alloy body to the final gauge. For example, the second stage can provide a reduction in thickness of about 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95, %, 96%, or 97%. In some examples, the second stage of the hot rolling process can provide a reduction in the range of 80% to 93%, for a total reduction in thickness of over 95%, for example about 99%. In some examples, as described further herein, the hot rolling step according to methods described herein can provide an appropriate balance of texture in the final materials in order to aid in superior properties of the alloy.
The hot rolled products can be cold rolled to a final gauge thickness. In some examples, cold rolling produces a total reduction in thickness of from about 60% to 99% (e.g., about 60% to 70%, about 60% to 80%, about 60% to 90%, about 70% to 98%, about 85% to 95%, or about 88% to 92%). In some cases, the cold rolling can be conducted in several individual cold rolling operations using a single stand reversing mill and/or a multi-stand tandem mill. For example, the cold rolling step can produces a total reduction in thickness of about 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%. The percent cold rolling, or % CR, is referred to in this context as the change in thickness due to cold rolling divided by the initial strip thickness prior to cold rolling. In some examples, multiple cold rolling steps are performed, each with a reduction in thickness in the range of about 40% to about 60% to achieve a total cold rolling reduction from a hot band to final gauge (e.g., from about 50% to about 55%, about 45% to about 55%, about 45% to about 60%, about 40% to about 50%, or about 55% to about 60%). For example, a first cold rolling operation produces a reduction in thickness of about 40%, 45%, 50%, 55%, or 60%, a second cold rolling operation produces a further reduction in thickness of about 40%, 45%, 50%, 55%, or 60% of the aluminum alloy body after the first cold rolling operation, and a third cold rolling operation produces a further reduction in thickness of about 40%, 45%, 50%, 55%, or 60% of the aluminum alloy body after the second cold rolling operation. In some examples, additional cold rolling steps can be employed, for example, a fourth cold rolling operation or a fifth cold rolling operation, or more. In some cases, between each of the multiple cold rolling steps, the aluminum alloy body can be cooled. Some additional examples are described in Example 4.
In some examples, an optional annealing step is performed between the hot rolling and the cold rolling steps. In some such examples, the annealing step can include subjecting the aluminum alloy body (e.g., a hot rolled coil) to a PMT from about 280° C. to about 480° C. for between about 0.5 hours to about 10 hours.
The annealing step can include heating the aluminum alloy body or hot band from room temperature to a temperature from about 280° C. to about 480° C. (e.g., from about 300° C. to about 450° C., from about 325° C. to about 425° C., from about 300° C. to about 400° C., from about 400° C. to about 480° C., from about 330° C. to about 470° C., from about 375° C. to about 450° C., or from about 450° C. to about 480° C.).
In some examples, an additional annealing step can be included after the cold rolling step. In some cases, this annealing step can be referred to as partial annealing. In some cases, the partial annealing is at a metal temperature from about 100° C. to about 300° C. for about 0.5 to about 10 hours. In some cases, the partial annealing can be conducted at a metal temperature from about 120° C. to about 280° C. and holding at that temperature for about 0.5 hours to about 4 hours. In another example, the partial annealing can be conducted at a PMT of about 150° C. to about 250° C. for about 1 hour to about 3 hours. In some cases, the partial annealing is at a PMT of about 240° C. for about 1 hour. In some cases, the partial annealing is at a PMT from about 210° C. to about 240° C.
The partial annealing step can include heating the alloy body or metal product from room temperature to a temperature from about 100° C. to about 300° C. (e.g., from about 120° C. to about 250° C., from about 125° C. to about 200° C., from about 200° C. to about 300° C., from about 150° C. to about 275° C., from about 225° C. to about 300° C., from about 210° C. to about 240° C. from about 220° C. to about 230° C., or from about 100° C. to about 175° C.).
In some examples, the first and second annealing processes can be performed in a batch process. In some examples, the first annealing process can be performed as a self-annealing step, for example, following hot rolling.
The alloys and methods described herein can be used to prepare highly shaped metal objects, such as aluminum cans or bottles. The cold rolled sheets described above can be subjected to a series of conventional can and bottle making drawing and wall ironing (DWI) processes to produce preforms according to other shaping processes as known to those of ordinary skill in the art. The shaped aluminum bottles may be used for beverages including but not limited to soft drinks, water, beer, energy drinks, and other beverages.
The foregoing description of certain examples, including illustrated examples, has been presented only for the purpose of illustration and description and is not intended to be exhaustive or to limit the disclosure to the precise forms disclosed. Numerous modifications, adaptations, and uses thereof will be apparent to those skilled in the art without departing from the scope of the disclosure.
Conventional aluminum bottles manufactured by multi-stage die necking of a drawn and wall-ironed preform have in some cases exhibited various types of defects at different stages of the manufacturing process, including excessive earing, out-of-roundness, shoulder dents formed during necking and splitting during curling. The severity of the dent can be determined upon visual inspection of the defects. In some cases, the number of visible shoulder dents on the products can be used as a measure of the severity of denting. In some cases, a minor amount of denting includes up to 2 shoulder dents (e.g., 0, 1, or 2 shoulder dents). In some cases, severe denting includes 4 shoulder dents on one product, including at 45°, 135°, 225°, and 315° angles.
Not to be bound by any theory, shoulder dents form relatively late in the sequence of necking operations and have generally been observed to be associated specifically with the “South-East” location at 45° around the bottle circumference as measured relative to the position at which the rolling direction of the original sheet is aligned with the vertical axis of the bottle (
A representative curve of the calculated Rang for a representative alloy at a given location on a bottle is shown in
During the necking process, where the sheet undergoes thickening under the imposed deformation, the average R-value increases at all locations. However, in some examples, the average R-value at the SE location increases more during the later stages of necking than at other locations. Not wishing to be bound by any theory, if the alloy is unable to uniformly deform at a location to conform with the deformation in immediately adjacent locations owing to differences in the average R-value, there is an incompatibility in the metal flow and localized denting can occur.
Conventional sheet materials with a higher susceptibility to denting contain a higher volume fraction of cube texture rotated around the RD (Cube_RD). Alloy design and choice of hot rolling conditions can promote the formation of high levels of cube texture in the hot rolled sheet. The alloys and methods described herein can provide high levels of ideal-oriented cube texture in the hot rolled sheet while avoiding the undesirable Cube_RD texture associated with denting. High levels of cube texture can balance the subsequent formation of rolling textures in the sheet during cold rolling and thus control the earing behavior of the sheet. High cold rolling reduction can be used to ensure low tensile spread and thus low defect rates due to splitting during curling, and in turn, higher levels of the ideal cube texture are then needed in the hot band to balance the strong associated rolling textures which are developed.
The alloys and the methods described herein can yield a product which simultaneously meets the mechanical properties and earing requirements, as well as requirements for low levels of defects such as splitting during curling and shoulder dents, for different applications, for example bottle making. Temperature is one variable that impacts texture in the hot band. The alloys and methods described herein can provide a desirable crystallographic texture in the hot band by adjusting the temperature during the final stages of hot rolling and subsequent coiling. To achieve the high level of cube texture desired for good earing balance in the final gauge sheet, the methods described herein employ a hot roll exit temperature that is sufficiently high to achieve full recrystallization in the hot band. Additionally though, these methods also employ a hot rolling exit temperature which is higher than a range just above that required for recrystallization in which there may be a tendency to promote high levels of the undesirable rotated cube texture.
The alloys and methods described herein can employ a temperature to ensure low denting susceptibility on the one hand, and good earing behavior on the other. As shown in
The specific compositional modifications described herein can promote ideal-oriented cube texture in the hot band while minimizing tensile spread for a given level of cold reduction. In some examples, the alloys and methods described herein can provide low susceptibility to dent formation. In some examples, the alloys and methods described herein can provide low earing. In some examples, the alloys and methods described herein can provide low tensile spread. In some examples, the alloys and methods described herein can provide the improved combination of attributes in the sheet to give low susceptibility to dent formation, low earing, and low tensile spread. This combination of attributes ensures good runnability and low levels of defects during the bottle making process and produces bottles with good appearance.
In some cases, the disclosed aluminum alloys have improved earing, which is determined by mean earing and earing balance. Earing is the formation of a wavy edge having peaks and valleys at the top edge of a drawn aluminum preform during processing. Earing is calculated by measuring the cup sidewall height around the circumference of the cup (from 0 to 360 degrees).
Mean earing is calculated by the equation:
In certain examples, the aluminum alloys can have an earing balance between −3.5% and 2.0%, such as between −3.0% and 2.0%, between −3.0% and 1.0%, or between −2.5% and 1.5%. In various aspects, the aluminum alloys have a mean earing of less than or equal to 5.5%, such as less than 5% or less than 4.5%. Earing is determined in accordance with European Standard EN 1669:1996, as further described in Example 5.
In addition to improved earing and cube texture, in some examples the methods disclosed herein can include cold rolling reduction sufficiently large enough to minimize the cell size in the deformation substructure of the final gauge sheet. In some examples, the methods disclosed herein can include cold rolling reduction sufficiently large enough to minimize the spacing of geometrically necessary boundaries (GNBs) in the substructure of the final gauge sheet. In some examples, the methods disclosed herein can include cold rolling reduction sufficiently large enough to minimize the cell size and GNB spacing in the substructure of the final gauge. Not wishing to be bound by any theory, the inventors discovered these microstructure features can aid dislocation annihilation and dynamic recovery during the multiple stages of the bottle-making process and thus produce an alloy that is more accommodating to strains and has a better defect performance.
In some examples, the products and materials made according to the alloys and methods described herein can include an average cell diameter size below 500 nm, for example, in some cases, below 400 nm, below 300 nm, or below 200 nm. In some examples, the products and materials made according to the alloys and methods described herein can include an average cell area of less than about 0.8 μm2, for example, in some cases, less than about 0.5 μm2, less than about 0.3 μm2, or less than about 0.15 μm2. In some cases, the substantial majority of cells has an area below 0.5 μm2. For medium and high cold reduction, the majority of cell area can be at or below 0.2 μm2. In some examples, the products and materials made according to the alloys and methods described herein can have a geometrically necessary boundary spacing distance of less than about 2 μm, for example, in some cases, below 1.8 μm, below 1.6 μm, or below 1.4 μm.
The following examples will serve to further illustrate the present invention without, at the same time, however, constituting any limitation thereof. On the contrary, it is to be clearly understood that resort may be had to various examples, modifications, and equivalents thereof which, after reading the description herein, may suggest themselves to those of ordinary skill in the art without departing from the spirit of the invention.
Four alloys, including Alloys V1, V3, V4, and V5, were prepared for cube texture measurement and earing testing. Alloys V1, V3, V4, and V5 were prepared according to the methods described herein with the hot rolling exit temperature range of 335° C. to 345° C., hot finishing mill reduction of 88.7% to 89.9%, and cold roll reduction range of 89% to 90%. The compositions of the alloys, including the iron to silicon ratio (Fe/Si Ratio) and weight percent ranges of Mg, Mn, and Cu, are shown in Table 7. Each of the alloys also includes Cr, Ni, Ti, Zn, and Zr in the amounts described herein and in equal amounts.
The volume fraction of cube texture for the alloys is shown in
The alloys described herein can adjust the level of mean earing and earing balance to achieve the desired earing performance.
The difference between alloys V4 and V5 processed under similar conditions is also shown in
The effect of cold rolling reduction on the cell size in the substructure of the final gauge sheet is shown in
The geometrically necessary boundaries (GNBs) in the microstructure and the effect of cold rolling reduction on the boundary spacing in Alloy V5 is shown in
The effect of the hot mill process on earing performance is shown in
The temperature and time profile of the alloy during cold rolling can also impact performance. A cold rolling practice that offers a warm exit temperature (70° C. to 200° C.) at each pass with a holding period to allow the coil to cool down before entering the next cold rolling pass can be utilized. Not to be bound by theory, this practice may allow the following microstructural evolution: (1) recovery of the microstructure after each pass; (2) promotion of dislocation alignment and annihilation and the development of GNBs; (3) promotion of precipitation of clusters/beta″/beta′ phase and clusters/S″/S′ phase which consume a part of the Mg in solid solution. With lower Mg in solid solution, together with planar slip promoters (clusters/beta″/beta′ phase and clusters/S″/S′ phase) formed during coil cooling, the tendency of forming an unfavorable Taylor lattice can be reduced and instead the favorable GNBs are more developed following cold rolling. Without coil cooling after each pass (e.g., by processing through a cold tandem mill), GNBs may not develop as well and thus the spread will be higher. Table 9 recites examples of the disclosed cold rolling processing.
The above table shows each pass as P1 (first pass or first cold roll operation), P2 (second pass or second cold roll operation), P3 (third pass or third cold roll operation), and P4 (fourth pass or fourth cold roll operation). “red.” means reduction.
The specific settings for the earing test conducted in accordance with European Standard EN 1669:1996 are provided in Table 10 below.
In another example, comparative alloys C1 and C2 and aluminum alloy V5′ were analyzed. The compositions are listed in Table 11 below (all amounts in wt. %):
V5′ and C1 were made according to the methods described herein with the hot rolling exit temperature range of 340° C. to 370° C. and cold roll reduction range of 86%. C2 was made according to the methods described herein with the hot rolling exit temperature range of 320° C. to 335° C. and cold roll reduction range of 91%. As shown in the data in the examples above, the alloys described herein demonstrate improved runnability as compared to conventional alloys. In trials, comparative alloys C1 and C2 showed high rates of splitting during curling and severe denting as compared to V5′.
As used below, any reference to a series of illustrative alloys, products, or methods is to be understood as a reference to each of those alloys, products, or methods disjunctively (e.g., “Illustrative embodiment 1-4” is to be understood as “Illustrative embodiment 1, 2, 3, or 4”).
Illustrative embodiment 1 is an aluminum alloy comprising about 0.2-0.8 wt. % Fe, 0.05-0.50 wt. % Si, 0.40-1.65 wt. % Mg, 0.40-1.50 wt. % Mn, 0.03-0.35 wt. % Cu, up to 0.07 wt. % Cr, up to 0.05 wt. % Ni, up to 0.07 wt. % Ti, up to 0.35 wt. % of Zn, up to 0.04 wt. % Zr, up to 0.15 wt. % impurities, with the remainder as Al, and wherein the alloy comprises an Effective Mg Index up to about 0.9.
Illustrative embodiment 2 is the aluminum alloy of any preceding or subsequent embodiment, comprising about 0.3-0.6 wt. % Fe, 0.12-0.36 wt. % Si, 0.65-1.22 wt. % Mg, 0.65-1.1 wt. % Mn, 0.05-0.25 wt. % Cu, up to 0.05 wt. % Cr, up to 0.03 wt. % Ni, up to 0.05 wt. % Ti, up to 0.25 wt. % of Zn, up to 0.03 wt. % Zr, and up 0.15 wt. % impurities, with the remainder as Al.
Illustrative embodiment 3 is the aluminum alloy of any preceding or subsequent embodiment, comprising about 0.36-0.44 wt. % Fe, 0.21-0.27 wt. % Si, 0.75-0.85 wt. % Mg, 0.75-0.85 wt. % Mn, 0.11-0.15 wt. % Cu, up to 0.05 wt. % Cr, up to 0.03 wt. % Ni, up to 0.05 wt. % Ti, up to 0.25 wt. % of Zn, up to 0.03 wt. % Zr, and up 0.15 wt. % impurities, with the remainder as Al.
Illustrative embodiment 4 is the aluminum alloy of any preceding or subsequent embodiment, comprising about 0.36-0.44 wt. % Fe, 0.21-0.27 wt. % Si, 0.75-0.85 wt. % Mg, 0.75-0.85 wt. % Mn, 0.06-0.1 wt. % Cu, up to 0.05 wt. % Cr, up to 0.03 wt. % Ni, up to 0.05 wt. % Ti, up to 0.25 wt. % of Zn, up to 0.03 wt. % Zr, and up 0.15 wt. % impurities, with the remainder as Al.
Illustrative embodiment 5 is the aluminum alloy of any preceding or subsequent embodiment, comprising about 0.36-0.44 wt. % Fe, 0.15-0.21 wt. % Si, 0.75-0.85 wt. % Mg, 0.75-0.85 wt. % Mn, 0.11-0.15 wt. % Cu, up to 0.05 wt. % Cr, up to 0.03 wt. % Ni, up to 0.05 wt. % Ti, up to 0.25 wt. % of Zn, up to 0.03 wt. % Zr, and up 0.15 wt. % impurities, with the remainder as Al.
Illustrative embodiment 6 is the aluminum alloy of any preceding or subsequent embodiment, comprising about 0.36-0.44 wt. % Fe, 0.21-0.27 wt. % Si, 0.75-0.85 wt. % Mg, 0.75-0.85 wt. % Mn, 0.18-0.22 wt. % Cu, up to 0.05 wt. % Cr, up to 0.03 wt. % Ni, up to 0.05 wt. % Ti, up to 0.25 wt. % of Zn, up to 0.03 wt. % Zr, and up 0.15 wt. % impurities, with the remainder as Al.
Illustrative embodiment 7 is the aluminum alloy of any preceding or subsequent embodiment, comprising about 0.46-0.54 wt. % Fe, 0.27-0.33 wt. % Si, 0.93-1.07 wt. % Mg, 0.8-0.94 wt. % Mn, 0.11-0.15 wt. % Cu, up to 0.05 wt. % Cr, up to 0.03 wt. % Ni, up to 0.05 wt. % Ti, up to 0.25 wt. % of Zn, up to 0.03 wt. % Zr, and up 0.15 wt. % impurities, with the remainder as Al.
Illustrative embodiment 8 is the aluminum alloy of any preceding or subsequent embodiment, further comprising a Fe to Si ratio of 0.5 to 6.7, 0.8 to 5, 1.3 to 2.1, 1.7 to 2.9, or 1.4 to 2.0.
Illustrative embodiment 9 is a bottle or can comprising the aluminum alloy of any preceding or subsequent embodiment.
Illustrative embodiment 10 is an aluminum sheet comprising the aluminum alloy of any preceding or subsequent embodiment.
Illustrative embodiment 11 is a method of producing a metal product from the aluminum alloy of any preceding or subsequent illustration, comprising casting an aluminum alloy to form an ingot or a slab, homogenizing the ingot or the slab, hot rolling the ingot or the slab to produce an aluminum alloy body, and cold rolling the aluminum alloy body to a metal product with a final gauge.
Illustrative embodiment 12 is the method of any preceding or subsequent embodiment, wherein the homogenizing step includes subjecting the ingot or slab to a temperature of from about 550° C. to about 625° C. for between 2 hours to 30 hours.
Illustrative embodiment 13 is the method of any preceding or subsequent embodiment, wherein the hot rolling step includes an entry temperature of from about 380° C. to about 500° C.
Illustrative embodiment 14 is the method of any preceding or subsequent embodiment, wherein the hot rolling step includes an exit temperature of from about 280° C. to about 400° C.
Illustrative embodiment 15 is the method of any preceding or subsequent embodiment, wherein a hot rolling exit temperature is greater than a recrystallization temperature of the aluminum alloy.
Illustrative embodiment 16 is the method of any preceding or subsequent embodiment, wherein the hot rolling step includes a first hot rolling operation that reduces the thickness of the ingot or slab in a range between 94% to 96% to provide an intermediate thickness and a second hot rolling operation that reduces the thickness of the ingot or slab having the intermediate thickness in a range between 80% to 93%.
Illustrative embodiment 17 is the method of any preceding or subsequent embodiment, wherein the cold rolling step includes reducing the aluminum alloy body by about 70% to 98% thickness reduction.
Illustrative embodiment 18 is the method of any preceding or subsequent embodiment, wherein the cold rolling step comprises a first cold rolling operation, a second cold rolling operation, a third cold rolling operation, and a fourth cold rolling operation.
Illustrative embodiment 19 is the method of any preceding or subsequent embodiment, wherein the cold rolling step comprises reducing the thickness of the aluminum alloy body between about 89% to 91%.
Illustrative embodiment 20 is the method of any preceding or subsequent embodiment, wherein each of the first cold rolling operation, the second cold rolling operation, the third cold rolling operation, and the fourth cold rolling operation provides a reduction in thickness in the range of about 40% to 60%.
Various embodiments of the invention have been described in fulfillment of the various objectives of the invention. It should be recognized that these embodiments are merely illustrative of the principles of the present invention. Numerous modifications and adaptations thereof will be readily apparent to those of ordinary skill in the art without departing from the spirit and scope of the invention as defined in the following claims.
This application claims priority to and filing benefit of U.S. Provisional Application No. 62/684,027 filed Jun. 12, 2018, which is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 62684027 | Jun 2018 | US |
