JP2023548476A - Improved 6XXX aluminum alloy - Google Patents

Abstract

A novel 6xxx aluminum alloy product and methods and systems for manufacturing the same are disclosed. The method includes heating a billet of 6xxx aluminum alloy to a preheating temperature, holding the billet at the preheating temperature for a period sufficient to dissolve the precipitation hardening phase of at least a portion of the billet, and extruding the billet. extruding the extruded product into a 6xxx aluminum alloy solvus product, in which both the billet and the extruded product are maintained above the preheating temperature during extrusion; The method may include discharging the extruded product from the extruder while maintaining the temperature within 100° F. of the extruder, and moving the extruded product from the heating shroud to the quenching device. [Selection diagram] Figure 1

Description

Press hardening of extruded 6xxx aluminum alloy products easily and quickly produces such extruded products without the need for a separate solution heat treatment step following the extrusion process. As commonly owned U.S. Pat. No. 7,422,645 explains, press-hardened products are placed in a liquid bath, such as oil or water, to rapidly remove heat from the product. It is rapidly cooled from the high deformation extrusion temperature by immersion. The purpose of hardening is to suppress phase transformations to increase hardness or obtain other desirable properties. When an aluminum alloy product, e.g. a billet or an ingot, is extruded, first the melting temperature of the precipitated phase of the aluminum matrix, e.g. the magnesium (Mg)-silicon (Si) phase of a billet made of Al-Mg-Si alloy, is is reheated to an alloy temperature above the melting temperature of and held at that temperature until the phases melt. The product is then rapidly cooled or quenched to the desired extrusion temperature to prevent new precipitation of these phases within the alloy structure, and extruded.

In general, this patent application relates to novel press-hardened 6xxx aluminum alloy products and methods and systems for making the same. The new methods and systems may, for example, facilitate the production of 6xxx aluminum alloy products with improved combinations of properties, such as improved strength and ductility (elongation).

<I. System and method>
Referring now to FIG. 1, one method (100) for manufacturing an extruded 6xxx aluminum alloy product is illustrated. In an exemplary embodiment, the method includes homogenizing a billet of 6xxx aluminum alloy (110), preheating the billet (120), and extruding the billet in an extrusion apparatus (130). discharging the extruded product from the extrusion apparatus (140) while maintaining the extruded product at a suitable pre-quench temperature (145); and quenching the extruded product (150). ) and artificially aging the extruded product (160). These steps will be explained in more detail below. One embodiment of a system (200) for completing method (100) is illustrated in FIG. 1-2 are used below to describe embodiments of the novel inventive method and system in a non-limiting manner.

The homogenization step (110) is optional and typically involves heating the billet of 6xxx aluminum alloy one or more times to one or more temperatures to homogenize the as-cast structure. After the homogenization step, the billet is usually cooled to room temperature and stored until extrusion. For purposes of this application and for ease of reference, the term "billet" encompasses both round billets and rectangular ingots.

If the billet is extruded, the preheating step (120), extrusion step (130), ejection step (140), and quenching step (150) are completed sequentially and without intervening steps. This is to ensure that a suitable microstructure is achieved in the final product.

Specifically, the billet is preheated (120) to a preheating temperature and then held at this temperature for a sufficient time to dissolve at least some precipitated phases of the billet. As shown in Figure 2, the preheating step (120) can be completed in a furnace (220). In one embodiment, the preheat temperature is at least 50% of the solvus temperature of the 6xxx aluminum alloy, but below the initial melting point of the 6xxx aluminum alloy. For example, if the solvus temperature is 962°F, "at least 50% of the solvus temperature" is ≧481°F, so the preheat temperature is ≧481°F, but below the initial melting point of the 6xxx aluminum alloy. .

As used in this disclosure, "solvus temperature" is the temperature at which all of the following precipitated phases will be completely dissolved in a 6xxx aluminum alloy billet at equilibrium without initial melting of the 6xxx aluminum alloy billet. means the lowest temperature.
・_Mg2Si
・Q phase (Al ₅ Cu ₂ Mg ₈ Si ₆ )
・Theta (θ) (Al ₂ Cu)
For clarity, the term "solvus temperature" includes only the phases mentioned above for the 6xxx aluminum alloy and does not include any other soluble precipitated phases, such as Mg ₂ Sn and Bi ₂ Mg ₃ .

In one embodiment, the preheat temperature is at least 60% of the solvus temperature of the 6xxx aluminum alloy, but below the initial melting point of the 6xxx aluminum alloy. In another embodiment, the preheat temperature is at least 70% of the solvus temperature of the 6xxx aluminum alloy, but below the initial melting point of the 6xxx aluminum alloy. In yet another embodiment, the preheat temperature is at least 80% of the solvus temperature of the 6xxx aluminum alloy, but below the initial melting point of the 6xxx aluminum alloy. In another embodiment, the preheat temperature is at least 90% of the solvus temperature of the 6xxx aluminum alloy, but below the initial melting point of the 6xxx aluminum alloy. In yet another embodiment, the preheat temperature is at least 95% of the solvus temperature of the 6xxx aluminum alloy, but below the initial melting point of the 6xxx aluminum alloy. In another embodiment, the preheat temperature is above the solvus temperature of the 6xxx aluminum alloy, but below the initial melting point of the 6xxx aluminum alloy. In yet another embodiment, the preheat temperature is at least 5° F. above the solvus temperature of the 6xxx aluminum alloy, but below the initial melting point of the 6xxx aluminum alloy. In another embodiment, the preheat temperature is at least 10° F. above the solvus temperature of the 6xxx aluminum alloy, but below the initial melting point of the 6xxx aluminum alloy. In yet another embodiment, the preheat temperature is at least 15° F. above the solvus temperature of the 6xxx aluminum alloy, but below the initial melting point of the 6xxx aluminum alloy. In another embodiment, the preheat temperature is at least 20° F. above the solvus temperature of the 6xxx aluminum alloy, but below the initial melting point of the 6xxx aluminum alloy. Generally, if high mechanical properties are required, the preheating temperature should be at least 90-100% of the solvus temperature, or higher.

The preheating step (120) also includes holding the billet at the preheating temperature for a time sufficient to dissolve at least some precipitated phases of the 6xxx aluminum alloy. Holding time may depend, for example, on billet size and desired final properties. In one embodiment, the preheating step (120) also includes holding the billet at the preheating temperature for a time sufficient to melt most or all of the precipitated phases of the 6xxx aluminum alloy. In one embodiment, the retention time is at least 1 minute. In another embodiment, the retention time is at least 5 minutes. In yet another embodiment, the retention time is at least 10 minutes. In another embodiment, the retention time is at least 20 minutes. In yet another embodiment, the retention time is at least 30 minutes. In another embodiment, the retention time is at least 40 minutes. In yet another embodiment, the retention time is at least 50 minutes or more. Typically, if high mechanical properties are required, the holding time at the preheat temperature must be sufficient to dissolve most or all of the precipitated phases of the 6xxx aluminum alloy. As will be appreciated, multiple preheat temperatures and corresponding multiple preheat hold times may be used.

In one embodiment, the preheat temperature is at least 950°F. In another embodiment, the preheat temperature is at least 960°F. In yet another embodiment, the preheat temperature is at least 970°F. In another embodiment, the preheat temperature is at least 975°F. In any of the above embodiments, the preheat hold time may be 40 to 60 minutes (eg, if the billet diameter is 15 inches diameter).

A non-limiting embodiment of a preheating step is shown in Figures 3a-3b. As shown, the billet is heated from (a) room temperature (T _{room temperature} ) to the preheat temperature. In this case, the preheating temperature is the metallurgically required temperature (T _MR ) or the temperature required to achieve high mechanical properties. As shown, the metallurgically required temperature (T _MR ) exceeds the solvus temperature (T _solvus ). Also as shown, the preheat holding time, referred to as t _mr and shown as (b) in Figures 3a-3b, is a typical length to dissolve most or all of the precipitated phases in 6xxx aluminum alloys. .

As further shown in Figures 3a-3b, the preheating temperature (T _MR ) is below the initial melting temperature or T _solidus , ie, no eutectic melting occurs. As shown in Figures 3a-3b, the extrusion process (described in more detail below) may further heat the product. This additional heating is generally necessary to ensure that the product does not exceed the initial melting temperature or T _solidus of the 6xxx aluminum alloy. Therefore, the preheat temperature is generally at least 10 degrees Fahrenheit below the initial melting temperature of the 6xxx aluminum alloy billet. In one embodiment, the preheat temperature is at least 20 degrees Fahrenheit below the initial melting temperature of the 6xxx aluminum alloy billet. In another embodiment, the preheat temperature is at least 30 degrees Fahrenheit below the initial melting temperature of the 6xxx aluminum alloy billet. In yet another embodiment, the preheat temperature is at least 40° F. below the initial melting temperature of the 6xxx aluminum alloy billet. In another embodiment, the preheat temperature is at least 50° F. below the initial melting temperature of the 6xxx aluminum alloy billet.

Referring again to FIGS. 1-2, after the preheating step (120), the preheated billet is immediately conveyed to an extrusion apparatus where the billet is extruded (130). As shown in FIG. 2, the term "immediately conveyed to an extrusion press" refers to the surface of the billet from the time it exits the preheating device (e.g., furnace 220) until the time it enters the extrusion device (e.g., extrusion press 230). , meaning a temperature drop of no more than 100°F. This is also shown in Figures 3a-3b, where the conveying step (c) shows a very small temperature drop. A small temperature drop is typically accomplished by utilizing short distances between the preheating equipment and the extrusion equipment, combined with suitable scheduling of billet flow through the various equipment of the system (200). Maintaining a small temperature drop from the preheating device to the extrusion device can easily obtain the desired microstructure and properties. The high preheating temperature used in the preheating step (120) allows the extrusion press (230) to quickly and efficiently extrude the billet into a final product during the extrusion step (130), increasing productivity. .

In one embodiment, the billet has a temperature drop within 75° F. from the time it exits the preheater to the time it enters the extrusion equipment. In another embodiment, the billet has a temperature drop within 50 degrees Fahrenheit from the time it exits the preheater to the time it enters the extrusion equipment. In yet another embodiment, the billet has a temperature drop within 40 degrees Fahrenheit from the time it exits the preheater to the time it enters the extrusion equipment. In another embodiment, the billet has a temperature drop within 30 degrees Fahrenheit from the time it exits the preheater to the time it enters the extrusion equipment. In yet another embodiment, the billet has a temperature drop within 20 degrees Fahrenheit from the time it exits the preheater to the time it enters the extrusion equipment. In another embodiment, the billet has a temperature drop within 10 degrees Fahrenheit from the time it exits the preheater to the time it enters the extrusion equipment. In yet another embodiment, the billet has a temperature drop within 5°F from the time it exits the preheater to the time it enters the extrusion equipment. In another embodiment, the billet has a temperature drop within 2°F from the time it exits the preheater to the time it enters the extrusion equipment.

The extrusion step (130) generally involves extruding the billet into a suitable end product, such as a bar, rod, tube, or composite shape, using extrusion equipment, such as an extrusion press (230). . The extrusion process can be accomplished by direct or indirect extrusion. In one method, the extrusion step (130) includes maintaining the billet and extruded product at or above a preheat temperature. In one embodiment, the extrusion process includes heating the extruded product during the extrusion process (130). Extrusion heating may be caused, for example, by friction applied to the billet by extrusion equipment (eg, extrusion press (230)) during the extrusion process. For example, as shown in Figures 3a-3b, during the extrusion step (d), the temperature of the product increases compared to the preheating temperature (T _MR ) and finally obtains the extrusion exit temperature (EET). Extrusion exit temperature (EET) is the temperature of the extruded product immediately after exiting the extrusion equipment. In one embodiment, the extrusion exit temperature (EET) is at least 10° F. higher than the preheat temperature. In another embodiment, the extrusion exit temperature (EET) is at least 20° F. higher than the preheat temperature. In yet another embodiment, the extrusion exit temperature (EET) is at least 30° F. higher than the preheat temperature. In another embodiment, the extrusion exit temperature (EET) is at least 40° F. higher than the preheat temperature. In yet another embodiment, the extrusion exit temperature (EET) is at least 50° F. higher than the preheat temperature.

The extruded product is then discharged from the extrusion apparatus (140). As part of the discharge step (140), the temperature of the extruded product is increased to the extrusion exit temperature (EET) until the product can be quenched (150) by water or other suitable quenching medium. maintained at a nearby temperature (145). This is also shown in Figures 3a-3b, where the temperature drop (e) from the extrusion step (d) to the quenching step (f) is small. In one method, the temperature of the extruded product is maintained within 100° F. of the extrusion exit temperature (EET) until the quenching step (150) is initiated. In one embodiment, the temperature of the extruded product is maintained within 75° F. of the extrusion exit temperature (EET) until the quenching step (150) is initiated. In another embodiment, the temperature of the extruded product is maintained within 50° F. of the extrusion exit temperature (EET) until the quenching step (150) is initiated. In yet another embodiment, the temperature of the extruded product is maintained within 40° F. of the extrusion exit temperature (EET) until the quenching step (150) is initiated. In another embodiment, the temperature of the extruded product is maintained within 30° F. of the extrusion exit temperature (EET) until the quenching step (150) is initiated. In yet another embodiment, the temperature of the extruded product is maintained within 20° F. of the extrusion exit temperature (EET) until the quenching step (150) is initiated. In another embodiment, the temperature of the extruded product is maintained within 10° F. of the extrusion exit temperature (EET) until the quenching step (150) is initiated. In yet another embodiment, the temperature of the extruded product is maintained within 5° F. of the extrusion exit temperature (EET) until the quenching step (150) is initiated.

In one embodiment, the maintaining step (145) includes maintaining the extruded product above the solvus temperature until the quenching step (150) begins. In one embodiment, the maintaining step (145) includes maintaining the extruded product at least 5° F. above the solvus temperature until quenching begins. In another embodiment, the maintaining step (145) includes maintaining the extruded product at least 10° F. above the solvus temperature until quenching begins. In yet another embodiment, the maintaining step (145) includes maintaining the extruded product at least 15° F. above the solvus temperature until quenching begins. In another embodiment, the maintaining step (145) includes maintaining the extruded product at least 20° F. above the solvus temperature until quenching begins. In yet another embodiment, the maintaining step (145) includes maintaining the extruded product at least 25° F. above the solvus temperature until quenching begins. In another embodiment, the maintaining step (145) includes maintaining the extruded product at least 30° F. above the solvus temperature until quenching begins. In yet another embodiment, the maintaining step (145) includes maintaining the extruded product at least 35° F. above the solvus temperature until quenching begins. In another embodiment, the maintaining step (145) includes maintaining the extruded product at least 40° F. above the solvus temperature until quenching begins.

As shown in FIG. 2, an outlet shroud (240) may be used to facilitate the maintenance process (145). An outlet shroud (240) may be directly adjacent to the outlet of the extrusion apparatus (230) to facilitate the maintenance step (145). For example, referring now to FIG. 4, as the billet is extruded through an extrusion die, it is discharged into an extrusion press tunnel. One or more passive and/or active heating devices may be located within the extrusion press tunnel. An example of a passive heating device is a surrounding shield designed to reflect heat radiated from the extruded product back toward the product. The peripheral shield can completely cover (eg, surround) the extruded product or can partially surround the extruded product. In one embodiment, the heat shield includes a material configured to reflect heat radiated from an extruded product, such as a metal (eg, stainless steel). For example, insulation materials, such as supported glass fibers, ceramic fibers, mineral wool blankets, may be used or alternatively may be used to maintain the temperature of the extruded product within the required tolerances. . Other devices that help retain heat include hot air curtains or physical curtains such as chain mail.

In one embodiment, the exit shroud (240), which can be in the form of an extrusion press tunnel (FIG. 4), can include one or more active heating devices. Examples of active heating devices include radiant heat lamps, hot air fans, resistance heaters, and the like. Both active and passive heating devices/materials may be used.

Referring again to FIGS. 1-2, after the discharge step (140), the extruded product is immediately transferred to a quenching device (250), such as a device that includes a stationary or movable water spray and/or water bath. , the product is rapidly quenched to a suitable low temperature, for example room temperature. This is illustrated, for example, in Figures 3a-3b, where the quenching step (f) rapidly quenches the extruded product received from the exit shroud to _{room temperature} T.

As mentioned above, the quenching step (150) is performed immediately after the ejection step (140). The quenching step is performed by contacting the exposed portion of the extruded product as it exits the exit shroud (240), i.e. when the exposed portion is no longer contained within the exit shroud (240). You can start. In one embodiment, the exposed portion of the extruded product is within 50° F. of the solvus temperature when the quenching medium first contacts the discharged extruded product. In another embodiment, the exposed portion of the extruded product is within 40° F. of the solvus temperature when the quenching medium first contacts the discharged extruded product. In yet another embodiment, the exposed portion of the extruded product is within 30° F. of the solvus temperature when the quenching medium first contacts the discharged extruded product. In another embodiment, the exposed portion of the extruded product is within 20° F. of the solvus temperature when the quenching medium first contacts the discharged extruded product. In yet another embodiment, the exposed portion of the extruded product is within 10° F. of the solvus temperature when the quenching medium first contacts the discharged extruded product. In another embodiment, the exposed portion of the extruded product is at or above the solvus temperature when the quenching medium first contacts the discharged extruded product. In yet another embodiment, the exposed portion of the extruded product is at least 5° F. above the solvus temperature when the quenching medium first contacts the discharged extruded product. In yet another embodiment, the exposed portion of the extruded product is at least 10° F. above the solvus temperature when the quenching medium first contacts the discharged extruded product. In yet another embodiment, the exposed portion of the extruded product is at least 15° F. above the solvus temperature when the quenching medium first contacts the discharged extruded product. In yet another embodiment, the exposed portion of the extruded product is at least 20° F. above the solvus temperature when the quenching medium first contacts the discharged extruded product. In yet another embodiment, the exposed portion of the extruded product is at least 25° F. above the solvus temperature when the quenching medium first contacts the discharged extruded product. In yet another embodiment, the exposed portion of the extruded product is at least 30° F. above the solvus temperature when the quenching medium first contacts the discharged extruded product. In yet another embodiment, the exposed portion of the extruded product is at least 35° F. above the solvus temperature when the quenching medium first contacts the discharged extruded product. In yet another embodiment, the exposed portion of the extruded product is at least 40° F. above the solvus temperature when the quenching medium first contacts the discharged extruded product. In yet another embodiment, the exposed portion of the extruded product is at least 45° F. above the solvus temperature when the quenching medium first contacts the discharged extruded product.

As mentioned above, the quenching step (150) may begin by contacting exposed portions of the extruded product as they exit the exit shroud (240). As shown in FIG. 4, this can be achieved by using a water spray placed directly adjacent to the outlet of the outlet shroud, which can be in the form of an extrusion press tunnel, for example. In one embodiment, the water contacts the exposed portion of the extrusion within 60 seconds of exiting the exit shroud. In another embodiment, the water contacts the exposed portion of the extrusion within 45 seconds after exiting the exit shroud. In yet another embodiment, the water contacts the exposed portion of the extrusion within 30 seconds after exiting the exit shroud. In another embodiment, the water contacts the exposed portion of the extrusion within 20 seconds of exiting the exit shroud. In yet another embodiment, the water contacts the exposed portion of the extrusion within 10 seconds of exiting the exit shroud. In another embodiment, the water contacts the exposed portion of the extrusion within 8 seconds after exiting the exit shroud. In yet another embodiment, the water contacts the exposed portion of the extrusion within 5 seconds of exiting the exit shroud.

With continued reference to FIG. 4, the quenching apparatus may include a quenching bath, such as an immersion bath (static water cooling). A quenching bath may be placed downstream of any quenching water spray. Using a water bath, the extruded product (extrudate) is easily further rapidly cooled to a suitable temperature (e.g., quenched to room temperature as shown in Figures 3a-3b (T _{room temperature} )). can do. In one embodiment, the relative motion between the extrudate and the water creates a shear flow on the surface of the extrudate, increasing cooling efficiency. In one embodiment, the water bath promotes a quenching rate of at least 1°F/sec. Water bath quench rate is determined by measuring the temperature of the extrudate before entering the water bath and measuring the time it takes for the extruded product to reach a temperature of 125°F. In another embodiment, the water bath promotes a quenching rate of at least 5°F/sec. In yet another embodiment, the water bath promotes a quenching rate of at least 10°F/sec. In another embodiment, the water bath promotes a quenching rate of at least 20°F/sec. In yet another embodiment, the water bath promotes a quenching rate of at least 30°F/sec.

Although water is used herein to describe the system/method of the present invention, any suitable quenching medium may be used, preferably in liquid form.

As shown in the Examples section below, steps (120)-(150) and their associated system components (220)-(250) result in improved microstructure and therefore improved properties. Easily produce press-hardened 6xxx aluminum alloy products with combinations. As illustrated in Figures 3a-3b, such press-hardened products can be immediately aged (g) and/or further cold-worked (h) (e.g. pultruded) without additional solution heat treatment fixation. )can do. For example, as illustrated in Figures 3a-3b, after quenching, the extruded product may be treated with either a T6, T8, or T9 temper. Such T6, T8 or T9 tempered products generally obtain an improved combination of properties with the press hardening methods and apparatus described herein.

Of course, the maintenance step (145) is optional. For example, in one embodiment, the extruded product can be discharged (140) from the extrusion apparatus without using an exit shroud (240). In such embodiments, the extruded product should be quenched (150) as soon as possible after the evacuation step (140) if high tensile properties are required.

<II. Composition>
As mentioned above, the new system and method can be applied to any 6xxx aluminum alloy suitable for extrusion. In one embodiment, the 6xxx aluminum alloy comprises 0.2-2.0 wt.% Si, 0.2-1.5 wt.% Mg, 0.07-1.0 wt.% Mn, up to 1.5 wt.% Bi wt%, Sn up to 1.5 wt%, Cu up to 1.0 wt%, Zn up to 1.0 wt%, Pb up to 0.7 wt%, Fe up to 0.7 wt%, Contains up to 0.35 wt% Cr, up to 0.35 wt% V, up to 0.25 wt% Zr, and up to 0.20 wt% Ti, with the balance being aluminum, any accompanying elements, and It is an impurity.

As used herein, "ancillary element" means an element or material other than those listed above that can optionally be added to an alloy to aid in its manufacture. Examples of accompanying elements include foundry aids, such as deoxidizers. Optional accessory elements may be included in the alloy in cumulative amounts up to 1.0% by weight. As one non-limiting example, one or more ancillary elements may be added to the alloy during casting to reduce or limit ingot cracking due to, for example, oxide wrinkles, pits, and oxide patches ( (excluding in some cases). These types of accessory elements are generally referred to herein as deoxidizing agents. Examples of some deoxidizing agents include Ca, Sr, and Be. When calcium (Ca) is included in the alloy, it is generally present in an amount up to about 0.05%, or up to about 0.03% by weight. In some embodiments, Ca is present in the alloy in an amount of about 0.001-0.03 wt.% or about 0.05 wt.%, such as 0.001-0.008 wt.% (or 10-80 ppm). included. Strontium (Sr) can be included in the alloy as a replacement for Ca (in whole or in part) and thus in the same or similar amount as Ca. Traditionally, the addition of beryllium (Be) has helped reduce the tendency of ingots to crack, but for environmental, health, and safety reasons, some embodiments of alloys have been modified to substantially contain Be. do not have. When Be is included in the alloy, it is generally present in amounts up to about 20 ppm. Accessory elements may be present in insignificant or significant amounts without departing from the alloys described herein, so long as the alloy retains the desirable properties described herein. , the accompanying elements may themselves add desirable or other properties. However, the scope of the present disclosure should not/is avoided by simply adding elements in quantities that would not otherwise affect the combination of properties desired and obtained herein. It should be understood that this cannot be done.

The new 6xxx aluminum alloy may contain small amounts of impurities. In one embodiment, the novel 6xxx aluminum alloy includes impurities totaling no more than 0.15% by weight, and the aluminum alloy includes no more than 0.05% by weight each impurity. In another embodiment, the novel 6xxx aluminum alloy includes impurities totaling no more than 0.10% by weight, and the aluminum alloy includes no more than 0.03% by weight each impurity.

In one embodiment, the 6xxx aluminum alloy is one of 6026LF, 6020, 6262A and 6061 aluminum alloys. The compositions of conventional 6020, 6262A, and 6061 alloys described herein are described in "International Alloy Resignations and Chemical Composition Limits for Wrout Aluminum and According to a document by the Aluminum Association entitled ``Aluminum Alloys'' (2015). The "6026LF" alloy is a lead-free version of the 6026 alloy, with 0.60-1.40 wt% Si, ≦0.70 wt% Fe, 0.20-0.50 wt% Cu, 0.20 wt% ~1.00 wt% Mn, 0.60-1.20 wt% Mg, ≦0.30 wt% Cr, ≦0.30 wt% Zn, ≦0.20 wt% Ti, ≦0 Contains .05 wt% Sn, ≦0.05 wt% Pb, and 0.50-1.50 wt% Bi, the balance being aluminum and impurities.

Although the present methods and systems have been described with respect to 6xxx aluminum alloys, such methods and systems can also be applied to other heat treatable (precipitation hardenable) aluminum alloys, such as 2xxx or 7xxx aluminum alloys. is expected. Accordingly, this patent application is also specifically directed to methods and systems for extruding 2xxx aluminum alloys and methods and systems for extruding 7xxx aluminum alloys. For 2xxx aluminum alloys, applicable solvus temperatures may include those associated with theta (θ), omega (Ω), and/or S phases, etc. For 7xxx aluminum alloys, applicable solvus temperatures include those associated with the eta (η) phase, etc.

<III. Microstructure＞
As mentioned above, 6xxx aluminum alloy products can realize the inventive microstructure. In one method, a 6xxx aluminum alloy measured from T/10 to 9T/10 in a 6xxx extruded product obtains an unrecrystallized microstructure, the unrecrystallized microstructure having at least 50% by volume of unrecrystallized Contains grains. In one embodiment, at least 60% of the unrecrystallized grains are fibrous grains. Fibrous grains are grains having an aspect ratio (grain length/diameter) of at least 5:1. In one embodiment, the average grain size of the unrecrystallized microstructure is 200 microns or less.

In another method, the 6xxx extruded product measured from T/10 of the 6xxx extruded product to 9T/10 obtains a recrystallized microstructure, and the recrystallized microstructure is at least 50 Contains vol% recrystallized grains. In one embodiment, at least 60% of the recrystallized grains have an aspect ratio of less than 5:1 (L:LT) (e.g., 1:1 to 4.9:1, or 1.5:1 to 4.9: 1) is an equiaxed grain. In one embodiment, the recrystallized microstructure has an average grain size of 200 microns or less.

<IV. Characteristics>
As mentioned above, the new 6xxx aluminum alloys can provide improved combinations of properties, such as improved strength and elongation.

In one embodiment, the novel 6xxx aluminum alloy is a novel 6026LF extruded product, ie, a product manufactured by the inventive methods and/or systems described herein. The new 6026LF extruded products can achieve at least 5% higher tensile yield strength (typical) and/or tensile strength (typical) than conventional press hardened 6026LF products. In one embodiment, the new 6026LF extruded product has at least a 10% higher tensile yield strength (typical) and/or Tensile strength (typical) can be obtained. In another embodiment, the new 6026LF extruded product has at least a 15% higher tensile yield strength (typical) and/or or tensile strength (typical). In yet another embodiment, the new 6026LF extruded product has at least a 20% higher tensile yield strength (typical) and / or tensile strength (typical) can be obtained. In one embodiment, the new 6026LF extruded product obtains a tensile yield strength (typical) (L) of at least 54 ksi, or at least 55 ksi, or at least 56 ksi, or at least 57 ksi, or more.

In one embodiment, the new 6026LF extruded product can be combined with at least 3% elongation (longitudinal or L) to obtain the above strength values. In another embodiment, the new 6026LF extruded product can be combined with an elongation (L) of at least 4% to obtain the above strength values. In yet another embodiment, the new 6026LF extruded product can be combined with an elongation (L) of at least 5% to obtain the above strength values. In another embodiment, the new 6026LF extruded product can be combined with an elongation (L) of at least 6% to obtain the above strength values. In yet another embodiment, the new 6026LF extruded product can be combined with an elongation (L) of at least 7% to obtain the above strength values. In another embodiment, the new 6026LF extruded product can be combined with an elongation (L) of at least 8% to obtain the above strength values. In another embodiment, the new 6026LF extruded product can be combined with an elongation (L) of at least 9% to obtain the above strength values. In yet another embodiment, the new 6026LF extruded product can be combined with an elongation (L) of at least 10% to obtain the above strength values.

In one method, a new extruded 6026LF aluminum alloy product has (a) a cubic (ED) texture of 17% by volume and (b) at least 9.5% by volume, as measured according to the "EBSD Sample Procedure" below. Obtain at least one of the 7 maximum ODF[001] intensities. In one embodiment, the extruded 6026LF aluminum alloy obtains at least 18 volume percent cubic (ED) texture, or at least 19 volume percent cubic (ED) texture. In one embodiment, the extruded 6026LF aluminum alloy product has at least 9.8, or at least 10.0, or at least 10.2, or at least 10.4, or at least 10.6, or at least 10.8. or obtain a maximum ODF[001] intensity of at least 11.0, or at least 11.2.

In one embodiment, the novel 6xxx aluminum alloy is a novel 6020 extruded product, ie, a product manufactured by the inventive methods and/or systems described herein. The new 6020LF extruded products are of the same product shape, size, and temper as conventional press-hardened 6020 products, such as the 6020 extruded products manufactured according to U.S. Patent No. 7,422,645. Tensile yield strength (typical) and/or tensile strength (typical) that is at least 5% higher than the manufactured product can be obtained. In one embodiment, the new 6020 extruded product has at least a 10% higher tensile yield strength (typical) and/or Tensile strength (typical) can be obtained. In another embodiment, the new 6020 extruded product has at least 15% higher tensile yield strength (typical) and/or or tensile strength (typical). In yet another embodiment, the new 6020 extruded product has at least a 20% higher tensile yield strength (typical) and / or tensile strength (typical) can be obtained. In one embodiment, the new extruded 6020 product is at least 34 ksi, or at least 35 ksi, or at least 36 ksi, or at least 37 ksi, or at least 38 ksi, or at least 39 ksi, or at least 40 ksi, or at least 41 ksi, or at least 42 ksi, or a tensile yield strength (typical) (L) of at least 43 ksi, or at least 44 ksi, or at least 45 ksi. In one embodiment, the new 6020 extruded product can be combined with an elongation (longitudinal or L) of at least 8% to obtain the above strength values. In another embodiment, the new 6020 extruded product can be combined with an elongation (L) of at least 9% to obtain the above strength values. In yet another embodiment, the new 6020 extruded product can be combined with an elongation (L) of at least 10% to obtain the above strength values. In another embodiment, the new 6020 extruded product can be combined with an elongation (L) of at least 11% to obtain the above strength values. In yet another embodiment, the new 6020 extruded product can be combined with an elongation (L) of at least 12% to obtain the above strength values. In another embodiment, the new 6020 extruded product can be combined with an elongation (L) of at least 13% to obtain the above strength values. In yet another embodiment, the new 6020 extruded product can be combined with an elongation (L) of at least 14% to obtain the above strength values. In another embodiment, the new 6020 extruded product can be combined with an elongation (L) of at least 15% to obtain the above strength values.

In one method, a new extruded 6020 aluminum alloy product has (a) a 17 volume percent cubic (ED) texture and (b) at least 3. Obtain at least one of the 6 maximum ODF[001] intensities. In one embodiment, the novel extruded 6020 aluminum alloy product has at least 18 volume percent cubic (ED) texture, or at least 19 volume percent cubic (ED) texture, or at least 20 volume percent cubic (ED) texture. ED) texture, or at least 21% cubic (ED) texture, at least 22% cubic (ED) texture, or at least 23% cubic (ED) texture, at least 24% cubic (ED) texture by volume; ED) texture, or at least 25% cubic (ED) texture, or at least 26% cubic (ED) texture, or at least 27% cubic (ED) texture, or more. In one embodiment, the new 6020 extruded aluminum alloy product is at least 3.8, or at least 4.0, or at least 4.2, or at least 4.4, or at least 4.6, or at least 4. 8, or at least 5.0, or at least 5.2, or at least 5.4, or at least 5.6, or at least 5.8, or at least 6.0, or at least 6.2, or at least 6.4, or obtain a maximum ODF[001] intensity of at least 6.6, or at least 6.8, or at least 7.0.

In one embodiment, the novel 6xxx aluminum alloy is a novel 6262A extruded product, ie, a product manufactured by the inventive methods and/or systems described herein. The new 6262A extruded products can have at least 5% higher tensile yield strength (typical) and/or tensile strength (typical) than conventional press hardened 6262A products. In one embodiment, the new 6262A extruded product has at least a 10% higher tensile yield strength (typical) and/or Tensile strength (typical) can be obtained. In another embodiment, the new 6262A extruded product has at least 15% higher tensile yield strength (typical) and/or or tensile strength (typical). In yet another embodiment, the new 6262A extruded product has at least a 20% higher tensile yield strength (typical) and / or tensile strength (typical) can be obtained. In one embodiment, the new 6262A extruded product is at least 37 ksi, at least 38 ksi, at least 39 ksi, or at least 40 ksi, or at least 41 ksi, or at least 42 ksi, or at least 43 ksi, or at least 44 ksi, or at least 45 ksi, or at least Obtain a tensile yield strength (typical) (L) of 46 ksi, or at least 47 ksi, or at least 48 ksi, or at least 49 ksi, or at least 50 ksi, or at least 51 ksi, or at least 52 ksi, or at least 53 ksi, or at least 54 ksi. In one embodiment, the new 6262A extruded product can be combined with at least 5% elongation (longitudinal or L) to obtain the above strength values. In another embodiment, the new 6262A extruded product can be combined with an elongation (L) of at least 6% to obtain the above strength values. In yet another embodiment, the new 6262A extruded product can be combined with an elongation (L) of at least 7% to obtain the above strength values. In another embodiment, the new 6262A extruded product can be combined with an elongation (L) of at least 8% to obtain the above strength values.

In one method, a new extruded 6262A aluminum alloy product has (a) an 18 volume percent cubic (ED) texture and (b) at least 3. Obtain at least one of the 9 maximum ODF[001] intensities. In one embodiment, the novel extruded 6262A aluminum alloy product has at least 19 volume percent cubic (ED) texture, or at least 20 volume percent cubic (ED) texture, or at least 21 volume percent cubic (ED) texture. ED) texture, at least 22 vol% cubic (ED) texture, or at least 23 vol% cubic (ED) texture, at least 24 vol% cubic (ED) texture, or at least 25 vol% cubic (ED) texture; ED) texture, or at least 26% cubic (ED) texture, or at least 27% cubic (ED) texture. In one embodiment, the new extruded 6262A aluminum alloy product is at least 3.8, or at least 4.0, or at least 4.2, or at least 4.4, or at least 4.6, or at least 4. 8, or at least 5.0, or at least 5.2, or at least 5.4, or at least 5.6, or at least 5.8, or at least 6.0, or at least 6.2, or at least 6.4, or obtain a maximum ODF[001] intensity of at least 6.6, or at least 6.8, or at least 7.0.

In one embodiment, the novel 6xxx aluminum alloy is a novel 6061 extruded product, ie, a product manufactured by the inventive methods and/or systems described herein. The new 6061 extruded products can have at least 5% higher tensile yield strength (typical) and/or tensile strength (typical) than conventional press hardened 6061 products. In one embodiment, the new 6061 extruded product has at least a 10% higher tensile yield strength (typical) and/or Tensile strength (typical) can be obtained. In another embodiment, the new 6061 extruded product has at least 15% higher tensile yield strength (typical) and/or or tensile strength (typical). In yet another embodiment, the new 6061 extruded product has at least a 20% higher tensile yield strength (typical) and / or tensile strength (typical) can be obtained. In one embodiment, the new extruded 6061 product is at least 22 ksi, or at least 24 ksi, or at least 26 ksi, or at least 28 ksi, or at least 30 ksi, or at least 32 ksi, or at least 34 ksi, or at least 36 ksi, or at least 38 ksi, or a tensile yield strength (typical) (L) of at least 40 ksi, or at least 42 ksi, or at least 44 ksi, or at least 47 ksi, or at least 48 ksi, or at least 49 ksi, or at least 50 ksi, or at least 51 ksi, or at least 52 ksi. obtain. In one embodiment, the new 6061 extruded product can be combined with an elongation (longitudinal or L) of at least 8% to obtain the above strength values. In another embodiment, the new 6061 extruded product can be combined with an elongation (L) of at least 10% to obtain the above strength values. In yet another embodiment, the new 6061 extruded product can be combined with an elongation of at least 12% (L) to obtain the above strength values. In another embodiment, the new 6061 extruded product can be combined with an elongation (L) of at least 14% to obtain the above strength values.

In one method, a new extruded 6061 aluminum alloy product has (a) a cubic (ED) texture of 5% by volume and (b) at least 2. Obtain at least one of the maximum ODF[001] intensities of 0. In one embodiment, the novel extruded 6061 aluminum alloy product has at least 6 vol.% cubic (ED) texture, or at least 7 vol.% cubic (ED) texture, or at least 8 vol.% cubic (ED) texture. ED) texture, or at least 9% cubic (ED) texture, at least 10% cubic (ED) texture, or at least 11% cubic (ED) texture, at least 12% cubic (ED) texture by volume; ED) texture, or at least 13% cubic (ED) texture, or at least 14% cubic (ED) texture, or at least 15% cubic (ED) texture, or at least 16% cubic (ED) texture. A cubic (ED) texture, or at least 17% by volume cubic (ED) texture is obtained. In one embodiment, the new extruded 6061 aluminum alloy product is at least 2.5, or at least 3.0, or at least 3.5, or at least 4.0, or at least 4.5, or at least 5. 0, or at least 5.5, or at least 6.0, or at least 6.5, or at least 7.0, or at least 7.5, or at least 8.0, or at least 8.5, or at least 9.0, or obtaining a maximum ODF[001] intensity of at least 9.5, or at least 10.0, or at least 10.2, or at least 10.4, or at least 10.6, or at least 10.8.

<V. Product usage>
The novel 6xxx extruded aluminum alloy products described herein can be used in a variety of product applications, such as rods, bars, shapes. Such products can be used in the manufacture of transmission valves (eg, of free-cutting 6xxx aluminum alloy containing Sn, Bi, and/or Pb). Structural parts for automobiles can also be produced. Extrusions can also be used as electrical connectors and in general industrial applications.

<VI. Definition>
"Hot working", eg, hot extrusion, means processing aluminum alloy products at elevated temperatures, generally at least 250 degrees Fahrenheit. Strain hardening is limited/avoided during hot working and generally distinguishes hot working from cold working.

"Cold working", eg, cold drawing, means processing an aluminum alloy product at temperatures that are not considered hot working temperatures, generally less than about 250° F. (eg, at ambient temperature).

The definition of temper is based on ANSI H35.1 (2009) titled "American National Standard Alloy and Temper Design Systems for Aluminum" published by the Aluminum Association.

Strength and elongation are measured according to ASTM E8/E8M-16a and B557-15.

<VII. Various matters>
These and other aspects, advantages, and novel features of this new technology are described in part by the following description, will be apparent to those skilled in the art from consideration of the following description and drawings, or will be provided by this disclosure. can be learned by implementing one or more embodiments of the techniques described.

The figures form a part of the specification, include example embodiments of the disclosure, and illustrate various objects and features thereof. Additionally, any measurements, specifications, etc. shown in the figures are intended to be illustrative and not restrictive. Accordingly, the specific structural and functional details disclosed herein are not to be construed as limitations, but merely as a representative basis to teach those skilled in the art the various uses of the present invention. It should be.

Among the disclosed advantages and improvements, other objects and advantages of the invention will become apparent from the following description in conjunction with the accompanying drawings. Although detailed embodiments of the invention are disclosed herein, it is to be understood, however, that the disclosed embodiments are merely illustrative of the invention, which may be embodied in various forms. . Furthermore, the examples set forth in connection with various embodiments of the invention are intended to be illustrative and not restrictive.

Throughout the specification and claims, the following terms have the meanings expressly associated with the specification, unless the context clearly dictates otherwise. As used herein, the phrases "in one embodiment" and "in some embodiments" do not necessarily refer to the same embodiment, although they may. Additionally, as used herein, the phrases "in another embodiment" and "in some other embodiments" do not necessarily refer to different embodiments, although they may. Accordingly, various embodiments of the invention may be readily combined without departing from the scope or spirit of the invention.

In addition, as used herein, the word "or" is a function word for the inclusive "or" and, unless the context clearly indicates otherwise, "and/or" is equivalent to a word. The term "based on" is not exclusive and can be based on additional elements not stated unless the context clearly indicates otherwise. Additionally, throughout this specification, "a," "an," and "the" include plural meanings unless the context clearly dictates otherwise. . "In" includes the meanings of "in" and "on" unless the context clearly indicates otherwise.

Although several embodiments of the invention have been described, it is understood that these embodiments are illustrative only and not limiting, and that many variations may become apparent to those skilled in the art. sea bream. Further, unless the context clearly requires, the various steps may be performed in any desired order, and any applicable steps may be added and/or removed.

FIG. 1 is a block diagram illustrating one embodiment of a method (100) for manufacturing an extruded 6xxx aluminum alloy product.

FIG. 2 is a block diagram illustrating one embodiment of a system (200) for manufacturing extruded 6xxx aluminum alloy products associated with the method of FIG.

FIG. 3a is a flowchart illustrating one method for manufacturing extruded 6xxx aluminum alloy products with T6 or T9 tempers.

FIG. 3b is a flowchart illustrating one method for manufacturing a T8 temper extruded 6xxx aluminum alloy product.

4 is a top schematic diagram of one embodiment of a portion of a system for manufacturing extruded 6xxx aluminum alloy products associated with the method of FIG. 1; FIG.

Figure 5a illustrates a photomicrograph of a conventional press hardened 6026LF product.

FIG. 5b illustrates a photomicrograph of a novel 6026LF product produced by the inventive systems and methods described herein.

Figure 6a is a photomicrograph of a 6026LF product manufactured in a conventional process using an alternative post-extrusion solution heat treatment.

FIG. 6b is a photomicrograph of a novel 6026LF product produced by the inventive systems and methods described herein.

FIG. 7a is a graph illustrating the characteristics of a 6026LF product produced by the inventive systems and methods described herein. FIG. 7b is a graph illustrating the characteristics of a 6026LF product produced by the inventive systems and methods described herein.

FIG. 8a illustrates a photomicrograph of a novel 6020 product manufactured by the inventive systems and methods described herein.

FIG. 9a is a photomicrograph (50 micrometer scale) of a novel 6020 product produced by the inventive systems and methods described herein.

Figure 9b is a micrograph (50 micrometer scale) of a 6020 product manufactured with a conventional press hardening process.

FIG. 9c illustrates another (200 micrometer scale) photomicrograph of the novel 6020 product produced by the inventive systems and methods described herein. FIG. 9d illustrates another (200 micrometer scale) photomicrograph of the novel 6020 product produced by the inventive systems and methods described herein.

FIG. 10a is a graph illustrating the characteristics of a 6020 product produced by the inventive systems and methods described herein. FIG. 10b is a graph illustrating the characteristics of a 6020 product produced by the inventive systems and methods described herein.

FIG. 11a illustrates a photomicrograph of the novel 6262A product manufactured by the inventive systems and methods described herein. FIG. 11b illustrates a photomicrograph of the novel 6262A product manufactured by the inventive systems and methods described herein.

FIG. 12a is a graph illustrating the characteristics of a 6262A product produced by the inventive systems and methods described herein. FIG. 12b is a graph illustrating the characteristics of the 6262A product produced by the inventive systems and methods described herein.

Figure 13a is a photograph showing the waste of a 6262A product manufactured in a conventional process using an alternative post-extrusion solution heat treatment.

FIG. 13b is a photograph showing the waste of a 6262A product produced by the inventive systems and methods described herein.

FIG. 14a is a graph illustrating the characteristics of a 6061 product produced by the inventive systems and methods described herein. FIG. 14b is a graph illustrating the characteristics of a 6061 product produced by the inventive systems and methods described herein.

<Example 1>

第二の本発明の方法を実施するために使用されるシステムは、図２および４に例示されるものと一致する。 Conventional 6026LF (lead-free) aluminum alloy was manufactured by two different methods. The basic steps of the two methods are shown in Table 1 below.

The system used to implement the second inventive method corresponds to that illustrated in FIGS. 2 and 4.

Micrographs of the extrudates were taken in the longitudinal direction. Figure 5a illustrates the microstructure of a 6026LF-T9 alloy processed by Method 1, conventional press hardening. Figure 5b illustrates the microstructure of a 6026LF-T9 alloy processed by method 2, the method of the invention. As shown, method 1 results in a 6026LF product with large recrystallized grains near the surface. On the contrary, method 2 produces fine fibrous unrecrystallized grains that are uniform in the cross-sectional direction. In addition, as shown in Figure 6b, the microstructure of method 2 can obtain a uniform distribution of fine and small constituent grains, and is not subjected to the conventional treatment of solution heat treatment in a completely separate furnace after extrusion. (Fig. 6a).

FIG. 7a illustrates the strength properties obtained by a 0.5625 inch extruded 6026LF-T9 rod manufactured according to Method 2. Figure 7b illustrates the elongation properties achieved by these same rods. As shown, the strength and elongation of the extruded rods significantly exceed ASTM requirements for 6026LF alloy. The measured property values are also shown in Table 2. (All values are in the long axis direction.)

The novel methods and systems described herein also improve the microstructure and properties of other 6xxx aluminum alloys. For example, Figure 8a shows a 6020 alloy prepared using a method consistent with that illustrated in Figures 1 and 3b (T8 temper) and using a system consistent with that illustrated in Figures 2 and 4. The microstructure of As shown, the grains of the extruded 6020 alloy are fibrous and uniform in the cross-sectional direction.

FIG. 9a illustrates a photomicrograph of a 6020 alloy product produced by the inventive methods and systems described herein. Figure 9b is a micrograph of a 6020 alloy product manufactured by a conventional press hardening process. The new 6020 product has fewer large tin-containing particles and the tin-containing particles are spheroidized. The finer and better dispersed tin-containing phase contributes to the improved machinability of 6xxx free-cutting alloys. Also, as shown in Figures 9c-9d, the new 6020 product yields small constituent grains that are evenly distributed. These particle sizes and particle size distributions are consistent with those of conventionally treated rods which are solution heat treated in a completely separate furnace after extrusion. The mechanical properties of 6020 alloy in rod form (1.16 inches at 20%, 25%, and 30% drawing) made with T8 temper by the method and system of the present invention are shown in FIGS. 10a-10b. As shown, the strength and elongation values are well above the 6020-T8 ASTM minimum. The measured characteristic values are also shown in Table 3 below. (All values are in the long axis direction.)

Alloy 6262A was also produced by the method and system of the present invention (e.g., consistent with FIGS. 1 and 3a (T9 temper) and FIGS. 2 and 4). Again, as shown in Figures 11a-11b, the new 6262A product contains small constituent grains, has a uniform particle size distribution, and is not conventionally processed by melt heat treatment in a completely separate furnace after extrusion. It matches that of the rod. The mechanical properties of 6262A alloy in rod form (0.5626 inch rod) made with T9 temper by the method and system of the present invention are shown in Figures 12a-12b. As shown, the strength and elongation values are well above the 6262A-T9 ASTM minimum. The measured characteristic values are also shown in Table 4 below. (All values are in the long axis direction.)

The machinability of 6262A rods produced by the methods and systems of the present invention is also significantly improved. As shown in Figure 13a, 6262A-T9 products manufactured using conventional post-extrusion solution heat treatment typically exhibit large amounts of very long debris. In contrast, as shown in Figure 13b, the new 6262A-T9 product manufactured using the inventive methods and systems described herein exhibits finer debris indicative of superior machinability. .

Alloy 6061 was also produced by the method and system of the present invention (e.g., consistent with FIGS. 1-2a (T6 temper) and FIGS. 3-4). The mechanical properties of 6061 alloy in rod form (1.50 inch rod) produced in T6 temper by the method and system of the present invention are shown in Figures 14a-14b. As shown, the strength and elongation values are again well above the 6061-T6 ASTM minimum. The measured characteristic values are also shown in Table 5 below. (All values are in the long axis direction.)

<Example 2>

Microstructural data of the alloy was obtained according to the EBSD sample procedure shown below. Table 6 shows some exemplary properties of the alloy. The maximum reported ODF texture strength is at the [001] plane of the cross section. Cubic texture and grain size values are in the transverse direction.

As shown in Table 6, the alloys produced by the method of the present invention obtain much higher maximum texture strengths than conventional press hardened and solution heat treated alloys. For example, the new 6020 extruded alloy is 203% (6.982/3.439 = 2.03) higher than the maximum ODF texture strength of the conventional extruded and press hardened 6020 alloy. Has maximum ODF texture strength.

Similarly, as shown in Table 6, the alloys produced by the method of the present invention have more cubic ED (direction of extrusion) aggregates than conventional press hardened and solution heat treated alloys. Get tissue. For example, the new 6020 extruded alloy has 9% more cubic ED texture than the conventional extruded and press-hardened 6020 alloy (26% vs. 17%).

Textured aluminum alloys have grains whose axes are not randomly distributed. Because the image can vary based on a variety of factors, the measured texture intensity is typically calculated by calculating an amount of background or random intensity and comparing that background intensity to the texture intensity of the image. It is normalized by The relative intensities of the resulting texture measurements are therefore dimensionless quantities that can be compared to each other to determine the relative amounts of different textures within a polycrystalline material. For example, in OIM analysis, a background (random) intensity can be measured and an directional distribution function (ODF) can be used to obtain an ODF intensity value. These ODF strength values can represent the amount of structure within a given aluminum alloy (or other polycrystalline material).

In this application, ODF intensities are measured according to the EBSD sample procedure (described below) or the substantially similar OIM procedure (where no X-ray diffraction is used), and a series of ODF plots containing intensity (time random) representations. can be created. The new 6xxx aluminum alloy products generally have high maximum ODF strengths and exhibit a large amount of texture. It is believed that the high amount of texture in the new 6xxx aluminum alloy products can contribute to improving their properties.

In one embodiment, the new extruded 6xxx aluminum alloy product is at least about Obtain 10% higher maximum ODF strength. For example, if a conventional extruded and press hardened 6026 alloy obtained a maximum ODF strength of 4.0, a new 6026 aluminum alloy product made by the novel process disclosed herein would A maximum ODF strength of at least 4.4 (10% higher than 4.0) can be obtained. In other embodiments, the new extruded 6xxx aluminum alloy product has at least a about 20% higher, or at least about 40% higher, or at least about 40% higher, or at least about 60% higher, or at least about 80% higher, or at least about 100% higher, or at least about 120% higher, or at least about 140% higher, or at least about 160% higher, or at least about 180% higher, or at least about 200% higher, or at least about 220% higher, or at least about 240% higher, or at least about 260% higher, or at least about 300 % higher, or at least about 340% higher, or at least about 360% higher, or at least about 380% higher, or at least about 400% higher, or at least about 420% higher, or at least about 440% higher, or at least about 460% A maximum ODF strength that is high, or at least about 480% higher, or at least about 500% higher, or more can be obtained.

In one embodiment, the new extruded 6xxx aluminum alloy product has at least an Obtain cubic ED texture with more volume %. For example, if a conventional extruded and press hardened 6026 alloy obtains a 15 volume percent cubic ED texture, a new 6026 aluminum alloy product made by the novel process disclosed herein will A cubic ED texture of 16 vol.% (1 vol.% more than 15 vol.%) can be obtained. In another embodiment, the new extruded 6xxx aluminum alloy product has at least 2 % more by volume, or at least 3% more by volume, or at least 4% more by volume, or at least 5% more by volume, or at least 6% more by volume, or at least 7% more by volume, or at least 8% more by volume, or at least 9% more by volume. % more, or at least 10 vol. % more, or at least 11 vol. % more, or at least 12 vol. % more, or at least 13 vol. % more.

<EBSD sample procedure>
- Electron backscatter diffraction (EBSD) is performed using a Thermo-Scientific ApreoS scanning electron microscope (SEM) or similar. The SEM operating conditions are: 68° sample tilt, 17 mm working distance, 20 kV acceleration voltage, and 51 nA spot size. EBSD patterns are collected using an EDAX Velocity camera with 4×4 binning and EDAX Orientation Image Microscopy software (OIM v.7.3.1) or similar. EBSD scans are performed using a square grid scan pattern and height and thickness dimensions of 2.8 mm.
- The collected scan data is processed using OIM TSL analysis software (v.8.0). Scan data is cleaned up using two processes. The first cleanup process is a near-orientation correlation with a minimum reliability of 0.1 and a grain tolerance angle of 5°. The second cleanup process is a grain dilation method that specifies the minimum grain size of five data points containing multiple columns. These two processes were run in one cleanup.
- Grain is defined as having a grain tolerance angle of 5° and a minimum of 5 points. The grain shape is assumed to be spherical. A particle size chart is then calculated using the diameter of the particle size. In the figure, particle size diameter is binned and plotted against area fraction.

Although various embodiments of the novel technology described herein have been described in detail, it is apparent that modifications and adaptations of these embodiments will occur to those skilled in the art. However, it should be clearly understood that such modifications and adaptations are within the spirit and scope of the disclosed technology. Various of the above unique features can be combined to create a variety of new 6xxx aluminum alloy products with improved combinations of properties. Additionally, these and other aspects, advantages, and novel features of this novel technology are described in part in the description that follows and that will become apparent to those skilled in the art upon consideration of the following description and drawings. or can be learned by implementing one or more embodiments of the techniques provided by this disclosure.

Claims (32)

6xxx extruded product,
0.2 to 2.0% by weight of Si,
0.2 to 1.5% by weight of Mg;
0.07 to 1.0% by weight of Mn;
Maximum of 1.5% Bi by weight,
up to 1.5% by weight of Sn;
Up to 1.0% by weight of Cu,
up to 1.0% by weight of Zn;
up to 0.7% by weight of Pb;
Fe of up to 0.7% by weight,
Cr up to 0.35% by weight;
V of up to 0.35% by weight;
Zr of up to 0.25% by weight,
Contains up to 0.20% by weight of Ti,
The remainder is aluminum, any accompanying elements, and impurities,
the 6xxx extruded product, measured from T/10 of the 6xxx extruded product to 9T/10, includes unrecrystallized microstructure;
the unrecrystallized microstructure comprises at least 50% by volume unrecrystallized grains;
At least 60% of the unrecrystallized grains are fibrous grains,
the fibrous grains have an aspect ratio (grain length/diameter) of at least 5:1;
6xxx extruded product, wherein the average grain size of the unrecrystallized microstructure is 200 microns or less. 6xxx extruded product,
0.2 to 2.0% by weight of Si,
0.2 to 1.5% by weight of Mg;
Maximum of 1.5% Bi by weight,
up to 1.5% by weight of Sn;
Up to 1.0% by weight of Cu,
up to 1.0% by weight of Zn;
less than 0.07% by weight of Mn;
up to 0.7% by weight of Pb;
Fe of up to 0.7% by weight,
Cr up to 0.35% by weight;
V of up to 0.35% by weight;
Zr of up to 0.25% by weight,
Contains up to 0.20% by weight of Ti,
The remainder is aluminum, any accompanying elements, and impurities,
the 6xxx extruded product, measured from T/10 of the 6xxx extruded product to 9T/10, comprises a recrystallized microstructure;
the recrystallized microstructure comprises at least 50% by volume recrystallized grains;
At least 60% of the recrystallized grains are equiaxed grains having an aspect ratio of 5:1 (L:LT) or less,
6xxx extruded product, wherein the recrystallized microstructure has an average grain size of 200 microns or less. the 6xxx extruded product comprises at least 1% more cubic (ED) texture compared to a conventional 6xxx extruded product;
6xxx extrusion according to any of claims 1 to 2, wherein the conventional 6xxx extruded product is a conventional press hardened product of comparable composition, product shape, size and temper. products. wherein the 6xxx extruded product has at least 2% by volume more cubic (ED) texture, or at least 3% more cubic (ED) texture by volume, or at least 4% by volume more cubic (ED) texture, or at least 5% more by volume cubic (ED) texture, or at least 6% more by volume cubic (ED) texture, or at least 7% more by volume cubic (ED) texture; or at least 8 vol.% more cubic (ED) texture, or at least 9 vol.% more cubic (ED) texture, or at least 10 vol.% more cubic (ED) texture, or at least 11 vol.% more cubic (ED) texture. 4. The 6xxx extruded product of claim 3, comprising a texture, or at least 12 vol% cubic (ED) texture, or at least 13 vol% cubic (ED) texture. the 6xxx extruded product comprises a maximum ODF[001] texture strength, the maximum ODF[001] texture strength being greater than the maximum ODF[001] texture strength of a conventional 6xxx extruded product; at least 10% higher,
6xxx extrusion according to any of claims 1 to 4, wherein the conventional 6xxx extruded product is a conventional press hardened product of comparable composition, product shape, size and temper. products. the extruded 6xxx extruded product is at least about 20% higher, or at least about 40% higher, or at least about 40% higher, or at least about 60% higher than the conventional 6xxx extruded product , or at least about 80% higher, or at least about 100% higher, or at least about 120% higher, or at least about 140% higher, or at least about 160% higher, or at least about 180% higher, or at least about 200% higher, or at least about 220% higher, or at least about 240% higher, or at least about 260% higher, or at least about 300% higher, or at least about 340% higher, or at least about 360% higher, or at least about 380% higher, or a maximum ODF[001] texture strength that is at least about 400% higher, or at least about 420% higher, or at least about 440% higher, or at least about 460% higher, or at least about 480% higher, or at least about 500% higher. 6xxx extruded product according to claim 5. The extruded 6026LF product has an extruded 6026LF product that obtains at least one of (a) a cubic (ED) texture of 17% by volume and (b) a maximum ODF[001] strength of at least 9.7. Aluminum alloy products. 8. The extruded 6026LF aluminum alloy product of claim 7, wherein the 6026LF product obtains at least 18% cubic (ED) texture, or at least 19% cubic (ED) texture. The extruded 6026LF aluminum alloy product has a particle diameter of at least 9.8, or at least 10.0, or at least 10.2, or at least 10.4, or at least 10.6, or at least 10.8, or at least 11. Extruded 6026LF aluminum alloy article according to any of claims 7 to 8, obtaining a maximum ODF [001] strength of 0, or at least 11.2. said extruded 6026LF product is at least 5% higher (Typical) in tensile yield strength (L), or at least 10% higher in tensile yield strength (Typical) than a conventional press hardened 6026LF extruded product. (L), or at least 15% higher tensile yield strength (typical) (L), or at least 20% higher tensile yield strength (typical) (L),
The extruded 6026LF of any of claims 7 to 9, wherein the conventional 6026LF extruded product is a conventional press hardened product of comparable product shape, size, and temper. Aluminum alloy products. The extruded 6026LF product according to any of claims 7 to 10, wherein the extruded 6026LF product obtains a tensile yield strength (typical) (L) of at least 54 ksi, or at least 55 ksi, or at least 56 ksi, or at least 57 ksi. 6026LF product. The extruded 6026LF product has an elongation of at least 3%, or at least 4%, or at least 5%, or at least 6%, or at least 7%, or at least 8%, or at least 9%, or at least 10% ( Extruded 6026LF product according to any of claims 7 to 11, obtaining a typical) (L). The extruded 6020 product is an extruded 6020 product that obtains at least one of (a) a cubic (ED) texture of 17% by volume and (b) a maximum ODF [001] strength of at least 3.6. Aluminum alloy products. The extruded 6020 product has at least 18% by volume cubic (ED) texture, or at least 19% by volume cubic (ED) texture, or at least 20% by volume cubic (ED) texture, or at least 21% by volume cubic (ED) texture. % cubic (ED) texture by volume, at least 22% cubic (ED) texture by volume, or at least 23% cubic (ED) texture by volume, at least 24% cubic (ED) texture by volume, or at least 25% cubic (ED) texture by volume. 14. The extruded 6020 aluminum alloy of claim 13, wherein the extruded 6020 aluminum alloy obtains a volume percent cubic (ED) texture, at least 26 volume percent cubic (ED) texture, or at least 27 volume percent cubic (ED) texture. product. The extruded 6020 aluminum alloy product has a particle diameter of at least 3.8, or at least 4.0, or at least 4.2, or at least 4.4, or at least 4.6, or at least 4.8, or at least 5. 0, or at least 5.2, or at least 5.4, or at least 5.6, or at least 5.8, or at least 6.0, or at least 6.2, or at least 6.4, or at least 6.6, An extruded 6020 aluminum alloy product according to any of claims 13 to 14, which obtains a maximum ODF [001] strength of at least 6.8, or at least 7.0. said extruded 6020 product is at least 5% higher (Typical) in tensile yield strength (L), or at least 10% higher in tensile yield strength (Typical) than a conventional press hardened 6020 extruded product. (L), or at least 15% higher tensile yield strength (typical) (L), or at least 20% higher tensile yield strength (typical) (L),
Extruded 6020 according to any of claims 13 to 15, wherein the conventional 6020 extruded product is a conventional press hardened product of comparable product shape, size and temper. Aluminum alloy products. wherein the extruded 6020 product is at least 34 ksi, or at least 35 ksi, or at least 36 ksi, or at least 37 ksi, or at least 39 ksi, or at least 40 ksi, or at least 41 ksi, or at least 42 ksi, or at least 43 ksi, or at least An extruded 6020 product according to any of claims 13 to 16, which obtains a tensile yield strength (typical) (L) of 44 ksi, or at least 45 ksi. The extruded 6020 product has an elongation of at least 8%, or at least 9%, or at least 10%, or at least 11%, or at least 12%, or at least 13%, or at least 14%, or at least 15% ( Extruded 6020 product according to any of claims 13 to 17, obtaining (L). The extruded 6262A product has an extruded 6262A product that obtains at least one of (a) a cubic (ED) texture of 18% by volume and (b) a maximum ODF [001] strength of at least 3.9. Aluminum alloy products. The extruded 6262A product has at least 19% by volume cubic (ED) texture, or at least 20% by volume cubic (ED) texture, or at least 21% by volume cubic (ED) texture, at least 22% by volume. % cubic (ED) texture, or at least 23 vol. % cubic (ED) texture, or at least 24 vol. % cubic (ED) texture, or at least 25 vol. % cubic (ED) texture, at least 26 vol. 20. The extruded 6262A aluminum alloy product of claim 19, wherein the extruded 6262A aluminum alloy product obtains a cubic (ED) texture of 10%, or at least 27% cubic (ED) by volume. The extruded 6262A aluminum alloy product has a particle diameter of at least 3.8, or at least 4.0, or at least 4.2, or at least 4.4, or at least 4.6, or at least 4.8, or at least 5. 0, or at least 5.2, or at least 5.4, or at least 5.6, or at least 5.8, or at least 6.0, or at least 6.2, or at least 6.4, or at least 6.6, 21. The extruded 6262A aluminum alloy article of any of claims 19-20, wherein the extruded 6262A aluminum alloy article obtains a maximum ODF [001] strength of at least 6.8, or at least 7.0. said extruded 6262A product is at least 5% higher (Typical) in tensile yield strength (L), or at least 10% higher in tensile yield strength (Typical) than a conventional press hardened 6262A extruded product. (L), or at least 15% higher tensile yield strength (typical) (L), or at least 20% higher tensile yield strength (typical) (L),
The extruded 6262A of any of claims 19 to 21, wherein the conventional 6262A extruded product is a conventional press hardened product of comparable product shape, size, and temper. Aluminum alloy products. Wherein the extruded 6262A product is at least 37 ksi, or at least 38 ksi, or at least 39 ksi, or at least 40 ksi, or at least 41 ksi, or at least 42 ksi, or at least 43 ksi, or at least 44 ksi, or at least 45 ksi, or at least 46 ksi, or at least Any of claims 19 to 22, obtaining a tensile yield strength (typical) (L) of 47 ksi, or at least 48 ksi, or at least 49 ksi, or at least 50 ksi, or at least 51 ksi, or at least 52 ksi, or at least 53 ksi, or at least 54 ksi. The extruded 6262A product described in . 24. The extruded 6262A product obtains an elongation (typical) (L) of at least 5%, or at least 6%, or at least 7%, or at least 8%. Extruded 6262A product. The extruded 6061 product has an extruded 6061 product that obtains at least one of (a) a cubic (ED) texture of 5% by volume and (b) a maximum ODF [001] strength of at least 2.0. Aluminum alloy products. The extruded 6061 product has at least 6% cubic (ED) texture, or at least 7% cubic (ED) texture, or at least 8% cubic (ED) texture, or at least 9% cubic (ED) texture. % cubic (ED) texture by volume, or at least 10% cubic (ED) texture by volume, at least 11% cubic (ED) texture by volume, or at least 12% cubic (ED) texture by volume, at least 13% cubic (ED) texture; % cubic (ED) texture by volume, or at least 14% cubic (ED) texture by volume, or at least 15% cubic (ED) texture by volume, or at least 16% cubic (ED) texture by volume; 26. The extruded 6061 aluminum alloy product of claim 25, obtaining a 17% cubic (ED) texture. The extruded 6061 aluminum alloy product has a particle diameter of at least 2.5, or at least 3.0, or at least 3.5, or at least 4.0, or at least 4.5, or at least 5.0, or at least 5. 5, or at least 6.0, or at least 6.5, or at least 7.0, or at least 7.5, or at least 8.0, or at least 8.5, or at least 9.0, or at least 9.5, or obtaining a maximum ODF [001] intensity of at least 10.0, or at least 10.2, or at least 10.4, or at least 10.6, or at least 10.8. Extruded 6061 aluminum alloy product. said extruded 6061 product is at least 5% higher (Typical) in tensile yield strength (L), or at least 10% higher in tensile yield strength (Typical) than a conventional press hardened 6061 extruded product. (L), or at least 15% higher tensile yield strength (typical) (L), or at least 20% higher tensile yield strength (typical) (L),
The extruded 6061 product of any of claims 25 to 27, wherein the conventional 6061 extruded product is a conventional press hardened product of comparable product shape, size, and temper. Aluminum alloy products. Wherein the extruded 6061 product is at least 22 ksi, or at least 24 ksi, or at least 26 ksi, or at least 28 ksi, or at least 30 ksi, or at least 32 ksi, or at least 34 ksi, or at least 36 ksi, or at least 38 ksi, or at least 40 ksi, or at least Obtaining a tensile yield strength (typical) (L) of 42 ksi, or at least 44 ksi, or at least 46 ksi, or at least 47 ksi, or at least 48 ksi, or at least 49 ksi, or at least 50 ksi, or at least 51 ksi, or at least 52 ksi, 29. The extruded 6061 product according to any of 28. Extrusion according to any of claims 25 to 29, wherein the extruded 6061 product obtains an elongation (typical) (L) of at least 8%, or at least 10%, or at least 12%, or at least 14%. Molded 6061 product. A method,
(a) heating a billet of 6xxx aluminum alloy to a preheating temperature;
(b) holding the billet at the preheating temperature for a sufficient time to dissolve at least some precipitation hardening phases of the billet;
(c) immediately transferring the billet to an extrusion device after the holding step;
(d) extruding the billet into an extruded product in the extrusion apparatus, wherein during the extrusion both the billet and the extruded product are maintained at or above the preheating temperature; extrusion molding;
(e) discharging the extruded product from the extrusion apparatus into an exit shroud, the exit shroud discharging the extruded product within 100° F. of the solvus temperature of the 6xxx aluminum alloy; to maintain, to discharge;
(f) transferring the extruded product from the heated shroud to a quenching device, the quenching device comprising at least one of a water spray and a water bath; quenching and moving the extruded product to a temperature of less than 125°F with a cooling rate of at least 1°F/sec. A system,
(a) a furnace configured to preheat an extruded billet of 6xxx aluminum alloy;
(b) an extrusion device adjacent to and downstream of the furnace, the extrusion device configured to extrude the billet into an extruded product;
(c) an exit shroud adjacent to and downstream of the extrusion apparatus, the exit shroud maintaining the extruded product within 100° F. of the solvus temperature of the 6xxx aluminum alloy; an exit shroud comprising;
(d) a quenching device located directly adjacent to and downstream of the extrusion device, the quenching device quenching the extruded product received from the exit shroud by 125°; a quenching device configured to cool to a temperature below F at a cooling rate of at least 1 F/sec.

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