HIGH-STRENGTH ALUMINUM STAMPINGS WITH TAILORED PROPERTIES

Abstract

High-strength aluminum components and methods for preparing a high-strength aluminum component are provided. Methods of forming high-strength aluminum components include heating an aluminum alloy blank above a solvus temperature, quenching the aluminum alloy blank, and stamping the aluminum alloy blank in a die to form an aluminum component having a predetermined shape. A plurality of localized plastic deformations are introduced to select regions of the aluminum component, and the aluminum component is subject to one or more aging treatments including heating the aluminum component to a temperature below the solvus temperature. The localized plastic deformations serve as nucleation sites for precipitation hardening during the one or more aging treatments to form a plurality of strengthened regions in the aluminum component.

Description

INTRODUCTION

This section provides background information related to the present disclosure which is not necessarily prior art.

Components formed using aluminum alloys have become ever more prevalent in various industries and applications, including general manufacturing, construction equipment, automotive or other transportation industries, home or industrial structures, aerospace, and the like. For example, aluminum alloys are commonly used in manufacturing industries for die-castings components, such as, for example, engine blocks and transmission cases in the automobile industry. Notably, aluminum alloys are often used to die-cast components with thin walls that require high strength and high ductility and that are lightweight. While many formed aluminum alloy components have sufficient strengths for many applications, there is a continual need to prepare aluminum alloy components having increased yield strengths. Specifically, with respect to automobiles, there is a continued need to reduce the mass and size of vehicle components without sacrificing requisite strength.

SUMMARY

This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.

The present disclosure relates to high-strength aluminum stampings with tailored mechanical properties.

In various aspects, the present disclosure provides an exemplary method for preparing a high-strength aluminum component. The method may include heating an aluminum alloy blank to a temperature greater than or equal to about 400° C. to less than or equal to about 600° C., and quenching the aluminum alloy blank to a temperature of less than or equal to about 40° C. The aluminum alloy blank may be stamped in a die to form an aluminum component having a predetermined shape. After the formed component is removed from the stamping die, one or more localized plastic deformations (e.g., permanent deformations) may be introduced into one or more select regions of the aluminum component. The aluminum component may be subsequently aged at a temperature of greater than or equal to about 100° C. to less than or equal to about 200° C. As the aluminum component ages, the localized plastic deformations may serve as nucleation sites for precipitation hardening and the formation of a one or more strengthened regions in the aluminum component.

In one variation, the one or more strengthened regions may have a first yield strength that is greater than or equal to about 20% more than a yield tensile strength of regions of the aluminum component lacking the one or more strengthened regions.

In one variation, the one or more strengthened regions may have a first yield strength of greater than or equal to about 600 MPa, while a second yield strength of regions of the aluminum component lacking the one or more strengthened regions may be greater than or equal to about 480 MPa to less than or equal to about 520 MPa.

In one variation, aging includes a first temperature aging treatment and a second temperature aging treatment. The first temperature aging treatment may include aging the aluminum component at a first temperature selected from temperatures ranging from greater than or equal to about 100° C. to less than or equal to about 200° C. The second temperature aging treatment may include aging the aluminum component at a second temperature selected from temperatures ranging from greater than or equal to about 100° C. to less than or equal to about 200° C.

In one variation, localized plastic deformations may be introduced between the first temperature aging treatment and the second temperature aging treatment.

In one variation, localized plastic deformations may be introduced after the second temperature aging treatment.

In one variation, aging may further include a third temperature aging treatment. The third temperature aging treatment may include aging the aluminum component at a third temperature selected from temperatures ranging from greater than or equal to about 100° C. to less than or equal to about 200° C.

In one variation, localized plastic deformations may be introduced between the second temperature aging treatment and the third temperature aging treatment.

In one variation, the one or more localized plastic deformations are formed in a linear pattern on the aluminum component to enhance the strength of the aluminum component in a direction parallel to the linear pattern.

In one variation, the one or more localized plastic deformations are discrete from one another and formed in a distributed pattern over the aluminum component to protect against localized bending of the aluminum component.

In one variation, the aluminum alloy blank is a 7000 series aluminum alloy comprising greater than or equal to about 1.2 weight % to less than or equal to about 2.0 weight % copper (Cu), greater than or equal to about 2.1 weight % to less than or equal to about 2.9 weight % magnesium (Mg), less than or equal to about 0.30 weight % manganese (Mn), less than or equal to about 0.40 weight % silicon (Si), less than or equal to about 0.50 weight % iron (Fe), greater than or equal to about 0.18 weight % to less than or equal to about 0.28 weight % chromium (Cr), greater than or equal to about 5.1 weight % to less than or equal to about 6.1 weight % zinc (Zn), less than or equal to about 0.20 weight % titanium (Ti), less than or equal to about 0.15 weight % of other elements individually present in amounts less than or equal to about 0.05 weight %, and a balance of aluminum (Al).

In one variation, localized plastic deformation may be introduced using a process selected from the group consisting of: re-drawing, friction stir processing, shot peening, roller burnishing, and combinations thereof.

In one variation, the heating, quenching, and stamping of the aluminum alloy blank may occur concurrently.

In one variation, the stamping of the aluminum alloy blank to form the aluminum component may occur at a temperature less than or equal to about 26° C.

In other aspects, the present disclosure provides another exemplary method for preparing a high-strength aluminum component. The method optionally includes heating an aluminum alloy blank in a die to a temperature greater than or equal to about 400° C. to less than or equal to about 600° C. to form an aluminum component having a predetermined shape and quenching the aluminum component in the die to a temperature of less than or equal to about 40° C. One or more localized plastic deformations may be introduced to select regions of the aluminum component by a process selected from the group consisting of: re-drawing, friction stir processing, shot peening, roller burnishing, and combinations thereof. The aluminum component may be aged at a temperature of greater than or equal to about 100° C. to less than or equal to about 200° C. As the aluminum component ages, the localized plastic deformations may serve as nucleation sites for precipitates which cause hardening and the formation of one or more strengthened regions in the aluminum component. The strengthened regions of the aluminum component may have a first yield strength that is greater than or equal to about 20% more than a second yield strength of regions of the aluminum component lacking the one or more strengthened regions.

In one variation, aging may include a first temperature aging treatment and a second temperature aging treatment. The first temperature aging treatment may include aging the aluminum component at a first temperature selected from temperatures ranging from greater than or equal to about 100° C. to less than or equal to about 200° C. The second temperature aging treatment may include aging the aluminum component at a second temperature selected from temperatures ranging from greater than or equal to about 100° C. to less than or equal to about 200° C.

In one variation, localized plastic deformation may be introduced between the first temperature aging treatment and the second temperature aging treatment.

In one variation, aging may further include a third temperature aging treatment. The third temperature aging treatment may include aging the aluminum component at a third temperature selected from temperatures ranging from greater than or equal to about 100° C. to less than or equal to about 200° C. Localized plastic deformations may be introduced between the second temperature aging treatment and the third temperature aging treatment.

In other aspects, the present disclosure provides another exemplary method for preparing a high-strength aluminum component. The method optionally includes heating an aluminum alloy blank to a temperature greater than or equal to about 400° C. to less than or equal to about 600° C. and quenching the aluminum alloy blank to a temperature of less than or equal to about 40° C. The aluminum alloy blank may be stamped in a die to form an aluminum component having a predetermined shape. The aluminum component may be subject to a first process selected from the group consisting of: re-drawing, friction stir processing, shot peening, roller burnishing, and combinations thereof. The aluminum component may then be aged at a first temperature selected from temperatures ranging from greater than or equal to about 100° C. to less than or equal to about 200° C. After the first temperature aging treatment, the aluminum component may be subject to a second process selected from the group consisting of: re-drawing, friction stir processing, shot peening, roller burnishing, or a combination thereof. The aluminum component may then be aged at a second temperature selected from temperatures ranging from greater than or equal to about 100° C. to less than or equal to about 200° C. The first and second processes may introduce a plurality of localized plastic deformations to select regions of the aluminum component. The localized plastic deformations may serve as nucleation sites for precipitation hardening during the first and second aging treatments to form a plurality of strengthened regions in the aluminum component.

In one variation, the twice aged aluminum component may be subject to a third process selected from the group consisting of: re-drawing, friction stir processing, shot peening, roller burnishing, and combinations thereof. The aluminum component may then be aged at a third temperature selected from temperatures ranging from greater than or equal to about 100° C. to less than or equal to about 200° C.

Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

DRAWINGS

The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

FIGS. 1A-1C are perspective views of an exemplary door beam of an automobile having one or more localized plastic deformations. FIG. 1A shows a plurality of localized plastic deformations in a linear discontinuous pattern. FIG. 1B shows a localized plastic deformation in a continuous linear discontinuous pattern. FIG. 1C shows another pattern of a plurality of localized plastic deformations discrete from one another and formed in a distributed pattern over the aluminum component.

FIG. 2 is a graphical illustration of an exemplary method for preparing a high-strength aluminum component.

Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.

DETAILED DESCRIPTION

Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific compositions, components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, elements, compositions, steps, integers, operations, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. Although the open-ended term “comprising,” is to be understood as a non-restrictive term used to describe and claim various embodiments set forth herein, in certain aspects, the term may alternatively be understood to instead be a more limiting and restrictive term, such as “consisting of” or “consisting essentially of.” Thus, for any given embodiment reciting compositions, materials, components, elements, features, integers, operations, and/or process steps, the present disclosure also specifically includes embodiments consisting of, or consisting essentially of, such recited compositions, materials, components, elements, features, integers, operations, and/or process steps. In the case of “consisting of,” the alternative embodiment excludes any additional compositions, materials, components, elements, features, integers, operations, and/or process steps, while in the case of “consisting essentially of,” any additional compositions, materials, components, elements, features, integers, operations, and/or process steps that materially affect the basic and novel characteristics are excluded from such an embodiment, but any compositions, materials, components, elements, features, integers, operations, and/or process steps that do not materially affect the basic and novel characteristics can be included in the embodiment.

Any method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed, unless otherwise indicated.

When a component, element, or layer is referred to as being “on,” “engaged to,” “connected to,” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other component, element, or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to,” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.

Although the terms first, second, third, etc. may be used herein to describe various steps, elements, components, regions, layers and/or sections, these steps, elements, components, regions, layers and/or sections should not be limited by these terms, unless otherwise indicated. These terms may be only used to distinguish one step, element, component, region, layer or section from another step, element, component, region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first step, element, component, region, layer or section discussed below could be termed a second step, element, component, region, layer or section without departing from the teachings of the example embodiments.

Spatially or temporally relative terms, such as “before,” “after,” “inner,” “outer,” “beneath,” “below,” “lower,” “above,” “upper,” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially or temporally relative terms may be intended to encompass different orientations of the device or system in use or operation in addition to the orientation depicted in the figures.

Throughout this disclosure, the numerical values represent approximate measures or limits to ranges to encompass minor deviations from the given values and embodiments having about the value mentioned as well as those having exactly the value mentioned. Other than in the working examples provided at the end of the detailed description, all numerical values of parameters (e.g., of quantities or conditions) in this specification, including the appended claims, are to be understood as being modified in all instances by the term “about” whether or not “about” actually appears before the numerical value. “About” indicates that the stated numerical value allows some slight imprecision (with some approach to exactness in the value; approximately or reasonably close to the value; nearly). If the imprecision provided by “about” is not otherwise understood in the art with this ordinary meaning, then “about” as used herein indicates at least variations that may arise from ordinary methods of measuring and using such parameters. For example, “about” may comprise a variation of less than or equal to 5%, optionally less than or equal to 4%, optionally less than or equal to 3%, optionally less than or equal to 2%, optionally less than or equal to 1%, optionally less than or equal to 0.5%, and in certain aspects, optionally less than or equal to 0.1%.

In addition, disclosure of ranges includes disclosure of all values and further divided ranges within the entire range, including endpoints and sub-ranges given for the ranges. As referred to herein, ranges are, unless specified otherwise, inclusive of endpoints and include disclosure of all distinct values and further divided ranges within the entire range. Thus, for example, a range of “from A to B” or “from about A to about B” is inclusive of A and B.

Example embodiments will now be described more fully with reference to the accompanying drawings.

Age hardening (i.e., precipitation hardening) processes are commonly used to increase the strength of metal alloys, including aluminum alloys. For example, as an aluminum component ages, the aluminum component strengthens (e.g., hardens) by the formation of microscopic and submicroscopic precipitate particles. Precipitation hardening includes heating the metal alloy to homogeneously distribute the alloy elements throughout the base metal to form a solid solution. As the alloy is cooled, the solute (e.g., dissolved alloy elements) may migrate out of the solution (e.g., precipitate) over time. The rate of precipitation may be controlled by environmental factors, including temperature and pressure. The precipitating alloy elements may nucleate to form a second phase that may reinforce and strengthen the crystal matrix structure. Grain boundaries of the crystal matrix are common nucleation sites. However, precipitates within the grain provide enhance strengthening when compared to precipitates on the grain. The present technology provides a method of promoting precipitation formation within the grains, thus further improving the strength of the formed component in select regions of the component.

Accordingly, in various aspects, the present technology provides a method for manufacturing a component, such as, for example, an automobile part, having improved strength. The present method comprises stamping an aluminum alloy and introducing one or more localized deformations thereafter followed by subsequent aging treatments. The localized plastic deformations may act as nucleation sites for precipitation hardening.

The method includes annealing an aluminum alloy blank to reduce the number of dislocations within the crystal lattice (e.g., line defects in the alloy's crystal structure) and improve the workability of the aluminum alloy blank. Annealing includes expeditiously heating the aluminum alloy blank to above a solvus temperature and maintaining that temperature until the alloy elements are substantially homogeneously distributed throughout the aluminum and a solid solution is obtained. For example only, annealing may include heating the aluminum alloy blank to a temperature greater than or equal to about 400° C. to less than or equal to about 600° C. at a rate of greater than or equal to about 1.0° C./s to less than or equal to about 100° C./s and maintaining that temperature for a period of greater than or equal to about 0.01 hours to less than or equal to 1.0 hours. Annealing time and temperature may depend upon the thickness of the aluminum alloy blank.

In certain instances, the present method includes annealing an aluminum alloy including greater than or equal to about 0.4 weight % to less than or equal to about 0.8 weight % of silicon (Si), less than or equal to about 0.7 weight % of iron (Fe), greater than or equal to about 0.15 weight % to less than or equal to about 4.9 weight % of copper (Cu), less than or equal to about 0.9 weight % manganese (Mn), greater than or equal to about 0.8 weight % to less than or equal to about 2.9 weight % magnesium (Mg), less than or equal to about 0.35 weight % chromium (Cr), less than or equal to about 6.1 zinc (Zn), less or equal to about 0.20 weight % titanium (Ti), less than or equal to about 0.15 weight % of other elements individually present in amounts less than or equal to about 0.05 weight %, and a balance of aluminum (Al).

In certain instances, the present method includes annealing an aluminum alloy blank selected from the group consisting of: 2xxx series aluminum alloys (e.g., two thousand series aluminum alloys), 6xxx series aluminum alloys (e.g., six thousand series aluminum alloys), 7xxx series aluminum alloys (e.g., seven thousand series aluminum alloys), and combinations thereof. Copper (Cu) is the principal alloying element of the 2xxx series aluminum alloys; however, other elements, for example magnesium (Mg) may also be specified. Magnesium (Mg) and silicon (Si) are the principal alloying elements of the 6xxx series aluminum alloys. Zinc (Zn) is the principal alloying element of the 7xxx series aluminum alloys; however, other elements, for example copper (Cu), magnesium (Mg), chromium (Cr), zirconium (Zr), and combinations thereof may also be specified. The aluminum alloy blanks may be provided as a sheet, roll, or coil.

Non-limiting examples of suitable aluminum alloys include aluminum alloy 2024, aluminum alloy 6061, aluminum 7075, and the like.

Aluminum alloy 2024 includes about 0.5 weight % of silicon (Si), about 0.5 weight % of iron (Fe), greater than or equal to about 3.8 weight % to less than or equal to about 4.9 weight % of copper (Cu), greater than or equal to about 0.3 weight % to less than or equal to about 0.9 weight % of manganese (Mn), greater than or equal to about 1.2 weight % to less than or equal to about 1.8 weight % of magnesium (Mg), less than or equal to about 0.1 weight % of chromium (Cr), less than or equal to about 0.25 of zinc (Zn), less than or equal to about 0.15 weight % of titanium (Ti), less than or equal to about 0.15 weight % of other elements individually present in amounts less than or equal to about 0.05 weight %, and a balance of aluminum (Al). For example only, the other elements may include zirconium (Zr), vanadium (V), and combinations thereof.

Aluminum alloy 6061 includes greater than or equal to about 0.4 weight % to less than or equal to about 0.8 weight % of silicon (Si), less than or equal to about 0.7 weight % of iron (Fe), greater than or equal to about 0.15 weight % to less than or equal to about 0.40 weight % of copper (Cu), less than or equal to about 0.15 weight % of manganese (Mn), greater than or equal to about 0.8 weight % to less than or equal to about 1.2 weight % of magnesium (Mg), greater than or equal to about 0.04 weight % to less than or equal to about 0.35 weight % of chromium (Cr), less than or equal to about 0.25 weight % zinc (Zn), less than or equal to about 0.15 weight % of titanium (Ti), less than or equal to about 0.15 weight % of other elements individually present in amounts less than or equal to about 0.05 weight %, and a balance of aluminum (Al).

Aluminum alloy 7075 includes greater than or equal to about 1.2 weight % to less than or equal to about 2.0 weight % copper (Cu), greater than or equal to about 2.1 weight % to less than or equal to about 2.9 weight % magnesium (Mg), less than or equal to about 0.30 weight % manganese (Mn), less than or equal to about 0.40 weight % silicon (Si), less than or equal to about 0.50 weight % iron (Fe), greater than or equal to about 0.18 weight % to less than or equal to about 0.28 weight % chromium (Cr), greater than or equal to about 5.1 weight % to less than or equal to about 6.1 weight % zinc (Zn), less than or equal to about 0.20 weight % titanium (Ti), less than or equal to about 0.15 weight % of other elements individually present in amounts less than or equal to about 0.05 weight %, and a balance of aluminum (Al).

In certain instances, an aluminum alloy 2024 blank may be heated to a temperature greater than or equal to about 488° C. to less than or equal to about 499° C. for a period greater than or equal to about 0.1 hours. In other instances, an aluminum alloy 6061 blank may be heated to a temperature greater than or equal to about 525° C. to less than or equal to about 535° C. for a period greater than or equal to about 0.1 hours. In other instances still, an aluminum alloy 7075 blank may be heated to a temperature greater than or equal to about 485° C. to less than or equal to about 495° C. for a period greater than or equal to about 0.1 hours.

After annealing, the solid solution may be subsequently quenched. Quenching includes cooling the aluminum alloy at a rate of greater than or equal to about 450° C./s to a temperature of less than or equal to about 40° C. freezing the solute elements in place preventing, substantially, the diffusion of the alloy elements. The quenched aluminum alloy may be comparatively soft and may be pressed or drawn to form the desired aluminum component. For example, the quenched aluminum alloy may be stamped in a die having a predetermined shape to form the desired aluminum component. For example only, with respect to an automobile, the die may be shaped to form A-pillars or B-pillars, roof bows or rails, or hinge pillars. In other instances, the solid solution may be simultaneously stamped and quenched to a temperature of less than or equal to about 40° C.

One or more plastic deformations may be introduced to one or more select regions of the aluminum component. In certain instances, one or more plastic deformations may be introduced to one or more select regions of the aluminum component after the formed component is removed from the stamping die. As noted above, in various aspects, the localized plastic deformations may act as nucleation sites for the precipitation (e.g., heterogeneous nucleation) of the alloy elements as the aluminum component ages. The alloy elements diffuse (e.g., precipitate) to the respective nucleation sites as the aluminum component is aged forming one or more strengthened regions of the aluminum components. The nucleation sites facilitate formation of the second phase because the surface energy is lower and the free energy barrier diminished. The select regions (e.g., the nucleation sites) of the aluminum component are chosen to allow the formed second phase to provide enhanced strength to the aluminum component. Because the localized plastic deformations may serve as nucleation sites for precipitates, the amount of subsequent age hardening is greater for the select regions than the surrounding regions. Resulting in a high strength aluminum component with select regions of even greater strength (e.g., strengthened regions).

The tensile strength of the nucleation sites (e.g., strengthened regions) following precipitations may be greater than or equal to about 20% more than the tensile strength of regions of the aluminum component not including the second phase. For example only, in instances where the aluminum component comprises aluminum alloy 2024, one or more strengthened regions may have a yield strength of greater than or equal to about 450 MPa, while regions of the aluminum component lacking the one or more strengthened may have a yield strength of about 380 MPa. In instances where the aluminum component comprises aluminum alloy 6061, the one or more strengthened regions may have a yield strength of greater than or equal to about 370 MPa, while regions of the aluminum component lacking the one or more strengthened may have a yield strength of about 315 MPa. In instances where the aluminum component comprises aluminum alloy 7075, the one or more strengthened regions may have a yield strength of greater than or equal to about 600 MPa, while regions of the aluminum component lacking the one or more strengthened may have a yield strength of about 500 MPa.

The plastic deformations may be introduced to select areas of the aluminum component to improve energy management during impact. In certain instances, the plastic deformations may be localized along convex and concave surfaces, alone or in combination, of the aluminum component. In other instances, plastic deformations may be introduced in a discontinuous linear fashion. For example, FIG. 1A illustrates an exemplary door beam 10 of an automobile having a first end 12 and a second end 14 and a plurality of ridges 16 extending therebetween and creating a plurality of concave and convex surfaces 18, 20, wherein the plastic deformations 22 are introduced in a linear pattern of discontinuous regions on at least one protruding (convex) surface 20 of a first ridge of the plurality of ridges 16. It should be noted that placement of such plastic deformations 22 is representative, but may in fact be disposed on other regions of the door beam 10. Further, FIG. 1B illustrates an exemplary door beam 30 of an automobile having a first end 32 and a second end 34 and a plurality of ridges 36 extending therebetween and creating a plurality of concave and convex surfaces 38, 40, wherein the plastic deformation 28 is introduced in a continuous linear pattern on at least one protruding (convex) surface 40 of a first ridge 36. Again, placement of such a plastic deformation 28 is representative, but may in fact be disposed on other regions of the door beam 30 where strengthening is desired.

In still other instances, the plastic deformations may be distributed throughout the aluminum component so to resist localized bending of the aluminum component. For example, FIG. 1C illustrates an exemplary door beam 46 of an automobile having a first end 48 and a second end 50 and a plurality of ridges 52 extending therebetween and creating a plurality of concave and convex surfaces 54, 56, wherein the plastic deformations 58 are distributed throughout the door beam 46. Thus, each deformation of the plurality of localized plastic deformations 58 is discrete from one another. The plurality of plastic deformations 58 is formed in a distributed pattern over the door beam 46 to protect against highly localized bending of the aluminum component.

In still other instances (not shown), plastic deformations may be introduced at various angles (e.g., non-parallel fashion) relative to the length of an exemplary door beam. In still other instances (not shown), plastic deformations may be introduced on surfaces of an exemplary door beam that are substantially perpendicular with respect to the principal plane of the exemplary beam.

Plastic deformations result following the application of sufficient loads or forces that permanently deform the component and may occur in a variety of processes. In certain instances, plastic deformations may be introduced using a process selected from the group consisting of: redrawing, friction stir processes, shot peening, roller burnishing, and combinations thereof. For example only, redrawing includes stamping the aluminum component into a second die having a plurality of abnormalities selectively placed. For example, the second die may include a plurality of dimples, protrusions, or nubs, of sufficient depth or length to introduce plastic deformations at room temperature. Friction stir processing includes forcibly inserting a blunt object coupled to a rotating tool into select regions of the aluminum component. Friction between the blunt object and the aluminum component results in localized heating that is sufficient to soften and deform the solid aluminum component without altering the macroscopic geometry of the aluminum component. Shot peening includes bombarding the aluminum component with individual steel balls having a high velocity at a predetermined angle using a precision apparatus. Roller burnishing includes pressing and rolling a hard ball or cylinder against a suitably supported workpiece (e.g., the stamped aluminum component) to plastically deform the surface region of the workpiece.

In certain instances, one or more localized plastic deformations may be introduced to one or more selected regions of the formed aluminum component after quenching and prior to the aging of the formed aluminum component (e.g., T-type designation: T8 or T3). In other instances, the formed aluminum component is aged and subsequently deformed (e.g., T-type designation: T9). In still other instances, the formed aluminum component may be aged multiple times and plastic deformations may be introduced between the aging cycles (see FIG. 2).

As the aluminum component ages the alloy elements diffuse to numerous nucleation sites to form a precipitate (e.g., a second phase). In certain instances, the aluminum component may be artificially aged. Artificial aging increases the rate of precipitation of the alloy elements as compared to natural aging occurring at room temperature (26° C.). Aging occurs at temperatures below the equilibrium solvus temperature and below the metastable miscibility gap, the Guinier-Preston (“GP”) zone solvus line. By way of non-limiting example, the aluminum component may be aged by heating the aluminum component to a select temperature of greater than or equal to about 100° C. to less than or equal to about 200° C. at a rate of greater than or equal to about 0.1° C./s to less than or equal to about 10° C./s. The selected temperature may be maintained for a predetermined period of greater than or equal to about 0.1 hours to less than or equal to 48 hours. After the predetermined period, the aluminum component may be returned to a temperature of less than or equal to about 40° C. at a rate of greater than or equal to about 1.0° C./s to less than or equal to about 1000° C./s.

In various instances, the aluminum component may be artificially aged using one or more heat treatments (i.e., double-aging heat-treatment cycle). For example, in certain instances, the aluminum component may be artificially aged using a first temperature aging treatment and a second temperature aging treatment. In such instances, the first temperature aging treatment may include aging the aluminum component at a first temperature selected from the range of temperatures of greater than or equal to about 100° C. to less than or equal to about 200° C.; and the second temperature aging treatment may include aging the aluminum component at a second temperature selected from the range of temperatures of greater than or equal to about 100° C. to less than or equal to about 200° C. The selected first temperature may be lower than the selected second temperature.

The aluminum component may be heated to the first temperature at a rate of greater than or equal to about 0.1° C./s to less than or equal to about 10° C./s. The aluminum component may be maintained at the first temperature for a first predetermined period of greater than or equal to about 0.1 hours to less than or equal to 48 hours. After expiration of the first predetermined period, the aluminum component may be returned to a temperature of less than or equal to about 40° C. at a rate of greater than or equal to about 1.0° C./s to less than or equal to about 1000° C./s. The aluminum component may be maintained at the temperature of less than or equal to about 40° C. for a second predetermined period of greater than or equal to about 0.1 hours to less than or equal to 1000 hours.

After expiration of the second predetermined period, the aluminum component may be heated to the second temperature at a rate of greater than or equal to about 0.1° C./s to less than or equal to about 10° C./s. The aluminum component may be maintained at the second temperature for a third predetermined period of greater than or equal to about 0.1 hours to less than or equal to 48 hours. After expiration of the third predetermined period, the aluminum component may be returned to a temperature of less than or equal to about 40° C. at a rate of greater than or equal to about 1.0° C./s to less than or equal to about 1000° C./s.

In other instances, the aluminum component may be artificially aged using three aging treatments. In such instances, the first temperature aging treatment may include aging the aluminum component at a first temperature selected from the range of temperatures of greater than or equal to about 100° C. to less than or equal to about 200° C.; the second temperature aging treatment may include aging the aluminum component at a second temperature selected from the range of temperatures of greater than or equal to about 100° C. to less than or equal to about 200° C.; and the third temperature aging treatment may include aging the aluminum component at a third temperature selected from the range of temperatures greater than or equal to about 100° C. to less than or equal to about 200° C. The third temperature may be higher than the first and second temperatures, and the second temperature may be higher than the first temperature.

In such instances, the aluminum component may be heated to the first temperature at a rate of greater than or equal to about 0.1° C./s to less than or equal to about 10° C./s. The aluminum component may be maintained at the first temperature for a first predetermined period of greater than or equal to about 0.1 hours to less than or equal to 48 hours. After expiration of the first predetermined period, the aluminum component may be returned to a temperature of less than or equal to about 40° C. at a rate of greater than or equal to about 1.0° C./s to less than or equal to about 1000° C./s. The aluminum component may be maintained at the temperature of less than or equal to about 40° C. for a second predetermined period of greater than or equal to about 0.1 hours to less than or equal to 1000 hours.

After expiration of the second predetermined period, the aluminum component may be heated to the second temperature at a rate of greater than or equal to about 0.1° C./s to less than or equal to about 10° C./s. The aluminum component may be maintained at the second temperature for a third predetermined period of greater than or equal to about 0.1 hours to less than or equal to 48 hours. After expiration of the third predetermined period, the aluminum component may be returned to a temperature of less than or equal to about 40° C. at a rate of greater than or equal to about 1.0° C./s to less than or equal to about 1000° C./s. The aluminum component may be maintained at the temperature of less than or equal to about 40° C. for a fourth predetermined period of greater than or equal to about 0.1 hours to less than or equal to 1000 hours.

After expiration of the fourth predetermined period, the aluminum component may be heated the third temperature at a rate of greater than or equal to about 0.1° C./s to less than or equal to about 10° C./s. The aluminum component may be maintained at the third temperature for a fifth predetermined period of greater than or equal to about 0.1 hours to less than or equal to 48 hours. After expiration of the fifth predetermined period, the aluminum component may be returned to a temperature of less than or equal to about 40° C. at a rate of greater than or equal to about 1.0° C./s to less than or equal to about 1000° C./s.

In certain instances, the aluminum component may be incidentally aged (e.g., heat treated) as the aluminum component is further processed. For example, in the instance of automobiles, the aluminum component may be further aged during the paint application and finishing processes.

Embodiments of the present technology are further illustrated through the following non-limiting examples.

EXAMPLE 1

FIG. 2 provides a graphical illustration of an exemplary method for preparing a high-strength aluminum component. The y-axis 60 references temperature in degree Celsius, and the x-axis 62 references time in hours. The exemplary method has two stages. The first stage 64 illustrates the annealing, quenching, stamping, deformation, and selected aging of the formed aluminum component. The second stage 66 illustrates incidental aging of the aluminum component including the localized plastic deformations.

First, an aluminum alloy blank is heated to about 490° C. at a rate of about 1.0° C./s. The aluminum alloy blank remains at about 490° C. for about 0.1 hours. The homogenized aluminum alloy is quenched at a rate of about 1000° C./s to a temperature less than or equal to about 40° C., and the soft aluminum alloy is stamped 68 to form an aluminum component having a predetermined shape. After stamping 68, the aluminum component is subjected to a first deformation process 70 and subsequently aged. The aluminum component is artificially aged by heating the aluminum component to a temperature of about 120° C. at a rate of about 1.0° C./s. The aluminum component remains at about 120° C. for about 5 hours before returning to a temperature less than or equal to about 40° C. at a rate of about 1.0° C./s.

After the first aging process, the aluminum component is subject to a second deformation process 72. After the second deformation process 72, the aluminum component is again artificially aged by heating the component to a temperature of about 160° C. at a rate of about 1.0° C./s. The aluminum component remains at about 160° C. for about 2 hours before returning to a temperature less than or equal to about 40° C. at a rate of about 1.0° C./s.

After the second aging process, the aluminum component is subject to a third deformation process 74. After the third deformation process 74, the aluminum component may be incidentally aged by heating the component to a temperature of about 180° C. at a rate of about 1.0° C./s. The aluminum component remains at about 180° C. for about 0.3 hours before returning to a temperature less than or equal to about 40° C. at a rate of about 1.0° C./s.

The aluminum component may remain at about 40° C. for about 10 hours before again being incidentally aged a second time by heating the component to a temperature of about 140° C. at a rate of about 1.0° C./s. The aluminum component remains at about 140° C. for about 0.3 hours before returning to a temperature less than or equal to about 40° C. at a rate of about 1.0° C./s.

The aluminum component may remain at about 40° C. for about 1 hours before again being incidentally aged a third time by heating the component to a temperature of about 130° C. at a rate of about 1.0° C./s. The aluminum component remains at about 130° C. for about 0.3 hours before returning to a temperature less than or equal to about 40° C. at a rate of about 1.0° C./s.

EXAMPLE 2

An aluminum alloy blank may be heated to about 495° C. at a rate of about 1.0° C./s. The aluminum alloy blank remains at about 495° C. for about 0.1 hours. The homogenized aluminum alloy is quenched at a rate of about 1000° C./s to about room temperature, and the soft aluminum alloy is stamped to form an aluminum component having a predetermined shape. After stamping, one or more localized deformations are introduced to one or more select regions of the aluminum component. The aluminum component having the one or more localized deformations is then subject to a variety of subsequent aging processes.

EXAMPLE 3

An aluminum alloy blank may be heated to about 530° C. at a rate of about 1.0° C./s. The aluminum alloy blank remains at about 530° C. for about 0.1 hours. The homogenized aluminum alloy is quenched at a rate of about 1000° C./s to about room temperature, and the soft aluminum alloy is stamped to form an aluminum component having a predetermined shape. After stamping, the aluminum component is subject to a first aging treatment. The first aging treatment includes heating the aluminum component to a temperature of about 160° C. at a rate of about 1.0° C./s, maintain the aluminum component at about 160° C. for about 5 hours, and returning the aluminum component to room temperature at a rate of about 1.0° C./s.

Prior to a second aging treatment, a one or more localized deformations are introduced to one or more selected regions of the aluminum component. The second aging treatment includes heating the aluminum component to a temperature of about 180° C. at a rate of about 1.0° C./s, maintain the aluminum component at about 180° C. for about 0.3 hours, and returning the aluminum component to room temperature at a rate of about 1.0° C./s.

The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

Claims

1. A method of preparing a high-strength aluminum component, the method comprising:

heating an aluminum alloy blank to a temperature greater than or equal to about 400° C. to less than or equal to about 600° C. and quenching the aluminum alloy blank to a temperature of less than or equal to about 40° C.;

stamping the aluminum alloy blank in a die to form an aluminum component having a predetermined shape;

introducing one or more localized plastic deformations to one or more select regions of the aluminum component; and

aging the aluminum component at a temperature of greater than or equal to about 100° C. to less than or equal to about 200° C., wherein the localized plastic deformations serve as nucleation sites for precipitation hardening during aging to form one or more strengthened regions in the aluminum component.

2. The method of claim 1, wherein the one or more strengthened regions has a first yield strength that is greater than or equal to about 20% more than a second yield strength of regions of the aluminum component lacking the one or more strengthened regions.

3. The method of claim 1, wherein the one or more strengthened regions has a first yield strength of greater than or equal to about 600 MPa, while a second yield strength of regions of the aluminum component lacking the one or more strengthened regions is greater than or equal to about 480 MPa to less than or equal to about 520 MPa.

4. The method of claim 1, wherein aging includes a first temperature aging treatment and a second temperature aging treatment, the first temperature aging treatment includes aging the aluminum component at a first temperature selected from temperatures ranging from greater than or equal to about 100° C. to less than or equal to about 200° C., and the second temperature aging treatment includes aging the aluminum component at a second temperature selected from temperatures ranging from greater than or equal to about 100° C. to less than or equal to about 200° C.

5. The method of claim 4, further comprising:

introducing localized plastic deformations between the first temperature aging treatment and the second temperature aging treatment.

6. The method of claim 5, further comprising:

introducing localized plastic deformations after the second temperature aging treatment.

7. The method of claim 4, wherein aging further includes a third temperature aging treatment, and the third temperature aging treatment includes aging the aluminum component at a third temperature selected from temperatures ranging from greater than or equal to about 100° C. to less than or equal to about 200° C.

8. The method of claim 7, further comprising:

introducing localized plastic deformations between the second temperature aging treatment and the third temperature aging treatment.

9. The method of claim 1, wherein the one or more localized plastic deformations are formed in a linear pattern on the aluminum component to enhance strength of the aluminum component in a direction parallel to the linear pattern.

10. The method of claim 1, wherein the one or more localized plastic deformations are discrete from one another and formed in a distributed pattern over the aluminum component to protect against localized bending of the aluminum component.

11. The method of claim 1, wherein the aluminum alloy blank is a 7000 series aluminum alloy comprising greater than or equal to about 1.2 weight % to less than or equal to about 2.0 weight % copper (Cu), greater than or equal to about 2.1 weight % to less than or equal to about 2.9 weight % magnesium (Mg), less than or equal to about 0.30 weight % manganese (Mn), less than or equal to about 0.40 weight % silicon (Si), less than or equal to about 0.50 weight % iron (Fe), greater than or equal to about 0.18 weight % to less than or equal to about 0.28 weight % chromium (Cr), greater than or equal to about 5.1 weight % to less than or equal to about 6.1 weight % zinc (Zn), less than or equal to about 0.20 weight % titanium (Ti), less than or equal to about 0.15 weight % of other elements individually present in amounts less than or equal to about 0.05 weight %, and a balance of aluminum (Al).

12. The method of claim 1, wherein the introducing of the one or more localized plastic deformations occurs by a process selected from the group consisting of: re-drawing, friction stir processing, shot peening, roller burnishing, and combinations thereof.

13. The method of claim 1, wherein the quenching and stamping of the aluminum alloy blank occur concurrently.

14. The method of claim 1, wherein the stamping the aluminum alloy blank occurs at a temperature less than or equal to about 26° C.

15. A method of preparing a high-strength aluminum component, the method comprising:

heating an aluminum alloy blank in a die to a temperature greater than or equal to about 400° C. to less than or equal to about 600° C. to form an aluminum component having a predetermined shape and quenching the aluminum component in the die to a temperature of less than or equal to about 40° C.;

introducing one or more localized plastic deformations to one or more select regions of the aluminum component by a process selected from the group consisting of: re-drawing, friction stir processing, shot peening, roller burnishing, and combinations thereof; and

aging the aluminum component at a temperature of greater than or equal to about 100° C. to less than or equal to about 200° C., wherein the localized plastic deformations serve as nucleation sites for precipitation hardening during the aging to form one or more strengthened regions in the aluminum component having a first yield strength that is greater than or equal to about 20% more than a second yield strength of regions of the aluminum component lacking the one or more strengthened regions.

16. The method of claim 15, wherein aging includes a first temperature aging treatment and a second temperature aging treatment, the first temperature aging treatment includes aging the aluminum component at a first temperature selected from temperatures ranging from greater than or equal to about 100° C. to less than or equal to about 200° C., and the second temperature aging treatment includes aging the aluminum component at a second temperature selected from temperatures ranging from greater than or equal to about 100° C. to less than or equal to about 200° C.

17. The method of claim 16, further comprising:

introducing localized plastic deformations between the first temperature aging treatment and the second temperature aging treatment.

18. The method of claim 16, wherein aging further includes a third temperature aging treatment, the third temperature aging treatment includes aging the aluminum component at a third temperature selected from temperature ranging from greater than or equal to about 100° C. to less than or equal to about 200° C., and localized plastic deformations are introduced between the second temperature aging treatment and the third temperature aging treatment.

19. A method of preparing a high-strength aluminum component, the method comprising:

heating an aluminum alloy blank to a temperature greater than or equal to about 400° C. to less than or equal to about 600° C. and quenching the aluminum alloy blank to a temperature of less than or equal to about 40° C.;

stamping the aluminum alloy blank in a die to form an aluminum component having a predetermined shape;

subjecting the aluminum component to a first process selected from the group consisting of: re-drawing, friction stir processing, shot peening, roller burnishing, and combinations thereof;

aging the aluminum component at a first temperature selected from temperatures ranging from greater than or equal to about 100° C. to less than or equal to about 200° C.;

subjecting the aged aluminum component to a second process selected from the group consisting of: re-drawing, friction stir processing, shot peening, roller burnishing, and combinations thereof; and

aging the aluminum component at a second temperature selected from temperatures ranging from greater than or equal to about 100° C. to less than or equal to about 200° C.,

wherein the first and second processes introduce a plurality of localized plastic deformations to select regions of the aluminum component, the localized plastic deformations serve as nucleation sites for precipitation hardening during the first and second aging treatments to form a plurality of strengthened regions in the aluminum component.

20. The method of claim 19, further comprising:

subjecting the twice aged aluminum component to a third process selected from the group consisting of re-drawing, friction stir processing, shot peening, roller burnishing, and combinations thereof; and

aging the aluminum component at a third temperature selected from temperatures ranging from greater than or equal to about 100° C. to less than or equal to about 200° C.