High Strength Aluminum Alloys

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This international PCT Application claims the benefit of priority from U.S.

Provisional Patent Application No. 61/951,309, filed March 11, 2014, entitled, "HIGH STRENGTH 6XXX ALLOY (HS6X)", and claims the benefit of priority from U.S. Provisional Patent Application No. 61/954,358, filed March 17, 2014, entitled, "HIGH STRENGTH 6XXX ALLOY (HS6X)", each of which is incorporated here by reference in its entirety.

FIELD OF THE INVENTION

[0002] The present disclosure is generally directed to new high strength aluminum alloys, more particularly 6XXX series aluminum alloys and methods of manufacturing the same.

BACKGROUND OF THE INVENTION

[0003] Automotive industries are moving towards pieces for their vehicles extruded with aluminum rather than having steel components due to the lower weight of aluminum. The lower weight makes fuel economy better which is required by CAFE (Corporate Average Fuel Economy) regulations. The movement from steel to aluminum has caused the demand for high strength alloys to increase significantly. Typically, a 7XXX aluminum alloy would be used because of the increased strength. However, 7XXX alloys are expensive to cast, take time to extrude and additional time to age to full strength - factors that increase the cost to customers. [0004] High strength alloys increase the potential for thinner extrusions and increase opportunities for reducing weight. Alloys with promising tensile yield strength results may nonetheless exhibit lower than desired elongation. Elongation can be improved by avoiding a mixed grain structure of unrecrystallized and coarse recrystallized grains and instead creating a fully recrystallized fine grain structure.

[0005] Therefore, there is a need for new high strength aluminum alloys that reduce the expenses and efforts associated with manufacture of 7XXX alloys. There is a need for new 6XXX series aluminum alloys to reduce the expenses and efforts associated with manufacture of 7XXX alloys. There is a need for new 6XXX series aluminum alloys exhibiting high strength with a recrystallized fine grain structure.

SUMMARY OF THE INVENTION

[0006] The invention relates to a class of new 6XXX series high strength aluminum alloys with a fine grain structure and methods of manufacture and extrusion. Inventive aluminum alloys of the invention comprise from about 0.90 percent to about 1.2 percent by weight silicon, up to about 0.5 percent by weight iron, from about 0.05 percent to about 0.3 percent by weight copper, up to about 0.75 percent by weight manganese, from about 0.70 percent to about 1.0 percent by weight magnesium, up to about 0.25 percent by weight chromium, up to about 0.05 percent by weight zinc, up to about 0.1 percent by weight titanium, with the balance consisting essentially of aluminum.

[0007] It is one object of the invention to provide an aluminum alloy that is cast as an ingot and homogenized to uniformly disperse the various elements. It is another object of the invention to extrude the cast aluminum through a press at an initial billet temperature and at a particular extrusion speed. It is another object of the invention to quench the aluminum material after it has been extruded through the press. In another aspect, a method of forming an extrusion having a recrystallized grain structure is disclosed, the extrusion having a thickness ranging from about 0.050 inch to about 0.500 inch.

[0008] One object of the invention is to artificially age the extruded aluminum material and produce a fine grain structure in the final aluminum product which exhibits superior yield strength and elongation properties. One object of the invention is to provide an aluminum alloy with a minimum tensile yield strength of about 320 MPa.

[0009] It is one object of the invention to provide a high strength aluminum alloy that is a suitable substitute for 7XXX series aluminum alloys for automotive development.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG. 1 of the drawings is a schematic cross section of an aluminum extrusion

(section 569310).

[0011] FIG. 2 of the drawings is a schematic cross section of an aluminum extrusion

(section 569510)

[0012] FIG. 3 of the drawings is a graphic representation of water quench rate for various charges of aluminum extrusion section 569310.

[0013] FIG. 4 of the drawings is a graphic representation of water quench rate for various charges of aluminum extrusion section 569510.

[0014] FIG. 5 of the drawings depicts locations for tensile testing of aluminum extrusion section 569310.

[0015] FIG. 6 of the drawings depicts locations for tensile testing of aluminum extrusion section 569510.

[0016] FIG. 7 of the drawings is a graphic representation of aluminum extrusion section 569310 natural age ultimate tensile strength against age time. [0017] FIG. 8 of the drawings is a graphic representation of aluminum extrusion section 569310 natural age yield strength against age time.

[0018] FIG. 9 of the drawings is a graphic representation of aluminum extrusion section 569310 natural age elongation against age time.

[0019] FIG. 10 of the drawings is a graphic representation of aluminum extrusion section 569310 artificial age ultimate tensile strength against age time.

[0020] FIG. 11 of the drawings is a graphic representation of aluminum extrusion section 569310 artificial age yield strength against age time.

[0021] FIG. 12 of the drawings is a graphic representation of aluminum extrusion section 569310 artificial age elongation against age time.

[0022] FIG. 13 of the drawings is a graphic representation of aluminum extrusion section 569510 artificial age ultimate tensile strength against age time.

[0023] FIG. 14 of the drawings is a graphic representation of aluminum extrusion section 569510 artificial age yield strength against age time.

[0024] FIG. 15 of the drawings is a graphic representation of aluminum extrusion section 569510 artificial age elongation against age time.

[0025] FIG. 16A of the drawings is a photomicrograph of a polished section of an aluminum alloy log of the invention (head, center at 200x magnification).

[0026] FIG. 16B of the drawings is a photomicrograph of a polished section of an aluminum alloy log of the invention (head, center at 500x magnification).

[0027] FIG. 17 of the drawings is a photomicrograph of a polished section of an aluminum alloy log of the invention (head, edge at lOOx magnification).

[0028] FIG. 18A of the drawings is a photomicrograph of a polished section of an aluminum alloy log of the invention (butt, center at 200x magnification). [0029] FIG. 18B of the drawings is a photomicrograph of a polished section of an aluminum alloy log of the invention (butt, center at 500x magnification).

[0030] FIG. 19 of the drawings is a photomicrograph of a polished section of an aluminum alloy log of the invention (butt, edge at 5 Ox magnification).

[0031] FIG. 20 of the drawings is a photomicrograph of a polished and electro lyrically etched section of an aluminum alloy log of the invention (head, center, at 5 Ox magnification).

[0032] FIG. 21 of the drawings is a photomicrograph of a polished and electro lyrically etched section of an aluminum alloy log of the invention (head, edge).

[0033] FIG. 22 of the drawings is a photomicrograph of a polished and electro lyrically etched section of an aluminum alloy log of the invention (butt, center at 5 Ox magnification)

[0034] FIG. 23 of the drawings is a photomicrograph of a polished and electrolytically etched section of an aluminum alloy log of the invention (butt, edge)

[0035] FIG. 24 of the drawings is a photograph of a cross section of aluminum extrusion section 569310 showing unrecrystallized regions.

[0036] FIG. 25 of the drawings is a photograph of a cross section of aluminum extrusion section 569310 showing unrecrystallized regions.

[0037] FIG. 26 of the drawings is a photograph of a cross section of aluminum extrusion section 569510 showing fine grain recrystallization.

[0038] FIG. 27 of the drawings is a photograph of a cross section of aluminum extrusion section 569510 showing fine grain recrystallization.

[0039] FIG. 28 of the drawings is a photograph of an electrolytically etched cross section of aluminum extrusion section 569310 showing unrecrystallized regions with coarse grain recrystallization. [0040] FIG. 29 of the drawings is a photograph of an electrolytically etched cross section of aluminum extrusion section 569510 showing fully recrystallized grain structure.

[0041] FIG. 30 of the drawings is a photograph of a transverse weld of aluminum extrusion section 569510.

[0042] FIG. 31 of the drawings is a photograph of a weld of aluminum extrusion section 569310.

[0043] FIG. 32 of the drawings is a schematic of the die design for section 569310.

[0044] FIG. 33 of the drawings is a schematic of the die design for section 569510.

[0045] FIG. 34 of the drawings is a graphic representation of yield strength against extrusion exit temperature for various charges of aluminum extrusion section 569310 artificially aged at 338/347°F for six hours.

DETAILED DESCRIPTION OF THE INVENTION

[0046] Embodiments of the present invention relate to high strength 6XXX series alloys comprising aluminum and additional elements. The alloys are cast into ingots and then heated or homogenized at a particular temperature range to uniformly disperse the alloying additions throughout the aluminum matrix. A billet of the inventive aluminum alloy is then extruded through a press at an initial billet temperature and at a particular extrusion speed, after which the resulting extruded aluminum product is quenched. The extrusion process is such that it provides suitable conditions for a fine grain recrystallized structure. Fine grain recrystallization is a primary objective of the inventive alloys described herein. The fine grain crystallization yields a final aluminum product with superior yield strength and elongation properties.

[0047] Artificial aging of the extruded aluminum material at a particular temperature for a particular time period provides suitable conditions for maximizing strength and elongation. [0048] CHEMISTRY AND CASTING

[0049] Aluminum alloys of the invention are high strength 6XXX alloys. In one embodiment, aluminum alloys of the invention comprise mostly aluminum along with at least about 1.05 weight percent silicon, at least about 0.12 weight percent copper, about 0.20 weight percent manganese, and at least 0.76 weight percent magnesium. Amounts of alloy components are stated in weight percent of alloy unless otherwise stated.

[0050] In one embodiment, aluminum alloys of the invention comprise from about

0.90 percent to about 1.2 percent by weight silicon, up to about 0.5 percent by weight iron, from about 0.05 percent to about 0.3 percent by weight copper, up to about 0.75 percent by weight manganese, from about 0.70 percent to about 1.0 percent by weight magnesium, up to about 0.25 percent by weight chromium, up to about 0.05 percent by weight zinc, up to about 0.1 percent by weight titanium, with the balance consisting essentially of aluminum.

[0051] In one embodiment, aluminum alloys of the invention comprise: about 1.13 weight percent silicon, about 0.17 weight percent iron, about 0.16 weight percent copper, about 0.21 weight percent manganese, about 0.80 weight percent magnesium, about 0.004 weight percent chromium, about 0.006 weight percent zinc, about 0.014 weight percent titanium, and the balance consisting essentially of aluminum.

[0052] In one embodiment the total amount of impurities in the aluminum alloy is approximately zero. In one embodiment the total amount of impurities in the aluminum alloy comprise about 0.15 percent by weight. In one embodiment the amount of any single impurity does not exceed about 0.05 percent by weight.

[0053] Silicon may be present in the alloy in an amount between about 0.90 percent to about 1.20 percent by weight. In one embodiment silicon is present in an amount between about 1.05 to about 1.12 percent by weight; in one embodiment silicon is present in an amount between about 1.05 to about 1.10 percent by weight. Silicon may be present in the alloy in an amount of about 0.90, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99, 1.00, 1.01, 1.02, 1.03, 1.04, 1.05, 1.06, 1.07, 1.08, 1.09, 1.10, 1.11, 1.12, 1.13, 1.14, 1.15, 1.16, 1.17, 1.18, 1.19, or 1.20 percent by weight.

[0054] Iron may be present in the alloy in an amount up to about 0.50 percent by weight. In one embodiment iron is present in an amount up to about 0.25 percent by weight. Iron may be present in the alloy in an amount of about zero, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.30, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.40, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, or 0.50 percent by weight.

[0055] Copper may be present in the alloy in an amount between about 0.05 percent to about 0.3 percent by weight. In one embodiment copper is present in an amount between about 0.05 to about 0.30 percent by weight; in one embodiment copper is present in an amount between about 0.12 to about 0.18 percent by weight; in one embodiment copper is present in an amount between about 0.09 to about 0.15 percent by weight. Copper may be present in the alloy in an amount of about 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, or 0.30 percent by weight.

[0056] Manganese may be present in the alloy in an amount up to about 0.75 percent by weight. In one embodiment manganese is present in an amount between about 0.15 to about 0.75 percent by weight; in one embodiment manganese is present in an amount between about 0.15 to about 0.20 percent by weight; in one embodiment manganese is present in an amount between about 0.51 to about 0.56 percent by weight.

[0057] Manganese may be present in the alloy in an amount of about 0.01, 0.02, 0.03,

0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.30, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.40, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, 0.50, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.60, 0.61, 0.62, 0.63, 0.64, 0.65, 0.66, 0.67, 0.68, 0.69, 0.70, 0.71, 0.72, 0.73, 0.74, or 0.75 percent by weight. While the amount of manganese present in the alloy may be below 0.10% or also zero, it is not preferred due to a lowering of fracture toughness. Manganese adds resistance to the recrystallization process and to form a completely recrystallized grain structure it is preferable that the manganese should be kept as close to zero as possible. Adding manganese, however, has positive effects on the fracture toughness of the material. Manganese is added to obtain fine grain recrystallization without negatively affecting the alloy's fracture toughness.

[0058] Magnesium may be present in the alloy in an amount between about 0.70 percent to about 1.0 percent by weight. In one embodiment magnesium is present in an amount between about 0.74 to about 0.80 percent by weight; in one embodiment magnesium is present in an amount between about 0.76 to about 0.82 percent by weight. Magnesium may be present in the alloy in an amount of about 0.70, 0.71, 0.72, 0.73, 0.74, 0.75, 0.76, 0.77, 0.78, 0.79, 0.80, 0.81, 0.82, 0.83, 0.84, 0.85, 0.86, 0.87, 0.88, 0.89, 0.90, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99, or 1.0 percent by weight.

[0059] Chromium adds resistance to the recrystallization process and to form a completely recrystallized grain structure it is preferable that the chromium should be kept as close to zero as possible. Chromium may be absent from the alloy (that is, zero percent by weight). Chromium may be present in the alloy in an amount up to about 0.250 percent by weight. In one embodiment chromium is present in an amount up to about 0.030 percent by weight; in one embodiment chromium is present in an amount up to about 0.010 percent by weight; in one embodiment chromium is present in an amount up to about 0.005 percent by weight. Chromium may be present in the alloy in an amount of about 0.005, 0.010, 0.015, 0.020, 0.025, 0.030, 0.035, 0.040, 0.045, 0.050, 0.055, 0.060, 0.065, 0.070, 0.075, 0.080, 0.085, 0.090, 0.095, 0.100, 0.105, 0.110, 0.115, 0.120, 0.125, 0.130, 0.135, 0.140, 0.145, 0.150, 0.155, 0.160, 0.165, 0.170, 0.175, 0.180, 0.185, 0.190, 0.195, 0.200, 0.205, 0.210, 0.215, 0.220, 0.225, 0.230, 0.235, 0.240, 0.245, or 0.250 percent by weight. Chromium is better at impeding recrystallization than manganese due to the different locations at which the dispersoids form.

[0060] Zinc may be present in the alloy in an amount up to about 0.050 percent by weight. In one embodiment zinc is present in an amount up to about 0.020 percent by weight; in one embodiment zinc is present in an amount up to about 0.005 percent by weight. Zinc may be present in the alloy in an amount of about zero, 0.005, 0.010, 0.015, 0.020, 0.025, 0.030, 0.035, 0.040, 0.045, or percent by weight.

[0061] Titanium may be present in the alloy in an amount up to about 0.100 percent by weight. In one embodiment titanium is present in an amount up to about 0.040 percent by weight; in one embodiment titanium is present in an amount up to about 0.015 percent by weight. Titanium may be present in the alloy in an amount of about zero, 0.005, 0.010, 0.015, 0.020, 0.025, 0.030, 0.035, 0.040, 0.045, 0.050, 0.055, 0.060, 0.065, 0.070, 0.075, 0.080, 0.085, 0.090, 0.095, or 0.100 percent by weight.

[0062] Impurities may be present in the alloy in a total amount up to about 0.150 percent by weight. Impurities may be present in the alloy in a total amount of about zero, 0.005, 0.010, 0.015, 0.020, 0.025, 0.030, 0.035, 0.040, 0.045, 0.050, 0.055, 0.060, 0.065, 0.070, 0.075, 0.080, 0.085, 0.090, 0.095, 0.100, 0.105, 0.110, 0.115, 0.120, 0.125, 0.130, 0.135, 0.140, 0.145, or 0.150 percent by weight.

[0063] Amounts of each element included in the inventive aluminum alloy (that is: silicon, iron, copper, manganese, magnesium, chromium, zinc, titanium, and impurities) may vary by between about 1% and about 25% of the desired value. Amounts of each element may vary by about 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, or 25% of the desired value. By way of non-limiting example, in an inventive alloy designed to comprise silicon at about 1.0 percent by weight where the amount of silicon may vary by 10%, the final alloy may comprise silicon at between about 0.9 percent by weight to about 1.1 percent by weight. In another non-limiting example, in an inventive alloy designed to comprise copper at about 0.15 percent by weight where the amount of copper may vary by 20%, the final alloy may comprise copper at between about 0.12 percent by weight to about 0.18 percent by weight.

[0064] The alloy may be cast into logs or billets according to conventional methods.

In particular, the alloy may be cast at a temperature above about 1300°F, more particularly between about 1310°F and about 1330°F. Logs may be cast into any appropriate size or shape as needed.

[0065] Directly after casting, the microstructure of the logs or billets may not be uniform due to the solidification process. Solidification starts with the a-aluminum, by nature of the phase diagram. The aluminum forms single crystal dendrites with respect to the direction of heat transfer while the area surrounding the dendrites is solute rich with Mg ₂ Si which needs to be dissolved. In order to uniformly disperse the alloying additions throughout the a-aluminum matrix, the cast aluminum is homogenized.

[0066] Homogenization may take place at a temperature below the casting temperature, preferably at a temperature between about 1045°F and about 1070°F. The cast aluminum should be homogenized at an elevated temperature and for sufficient time to permit the alloying elements energy needed to diffuse into the aluminum dendrite arms to develop a more uniform microstructure. In one embodiment, homogenization occurs over the span of several hours, in one embodiment homogenization occurs over about four hours. Homogenization may occur in a furnace such as a Canefco furnace. [0067] EXTRUDING AND QUENCHING

[0068] After casting the aluminum alloy into a log or billet, the aluminum is extruded through a press to obtain a desired shape or form. The billet may be extruded through the press at any appropriate temperature based on the size and shape of the extrusion. Initial billet temperature should be selected to ensure the material has the ability to extrude easily. The temperature is chosen for productivity and ensuring a fine grain recrystallized structure. Initial billet temperature may be below the homogenization temperature. In one embodiment the initial billet temperature is over about 800°F; in one embodiment the initial billet temperature is between about 840°F and about 880°F; in one embodiment the initial billet temperature is between about 850°F and about 870°F; the initial billet temperature may be about 850°F, about 855°F, about 860°F, about 865°F, or about 870°F.

[0069] The billet may be extruded through the press using a ram at any appropriate speed based on the size and shape of the extrusion. In one embodiment the press ram speed is between about 9.0 and about 13.0 inches per minute; in one embodiment the press ram speed is between about 9.0 and about 10.0 inches per minute; in one embodiment the press ram speed is between about 12.0 and about 12.5 inches per minute.

[0070] The aluminum material exits the extruder at an exit temperature greater than the initial billet temperature. In one embodiment the exit temperature of the aluminum material is about 1040°F. Higher temperatures are preferred over lower exit temperatures because lower exit temperatures negatively affects the strength of the metal.

[0071] Following exit from the extrusion press, the aluminum material is quenched with water. The temperature is decreased from a temperature of approximately the exit temperature down to approximately ambient temperature over the span of several seconds. In one embodiment the aluminum material is quenched in between about 8 to about 16 seconds; in one embodiment the aluminum material is quenched in between about 10 to about 14 seconds; the aluminum material may be quenched in about 8 seconds, about 9 seconds, about 10 seconds, about 11 seconds, about 12 seconds, about 13 seconds, about 14 seconds, about 15 seconds, or about 16 seconds.

[0072] Sections of the aluminum extrusion may have any suitable thickness, and the preferred thickness of extrusion sections may range from about 0.050 inch to about 0.500 inch. In one embodiment the thickness of each wall of an aluminum extrusion is between about 0.080 and about 0.200 inches; in one embodiment the thickness of each wall of an aluminum extrusion is between about 0.080 and about 0.150 inches.

[0073] ARTIFICIAL AGING

[0074] After quenching, the extruded aluminum material may be placed in a furnace to stabilize it. Stabilization may occur at any appropriate furnace temperature for any appropriate time; in one embodiment the furnace temperature is about 250°F and the aluminum is stabilized in the furnace for about two hours.

[0075] To achieve full strength, the aluminum extrusion must be artificially aged by heating the aluminum material to an appropriate temperature for an appropriate time. Artificial aging temperatures may range from about 300°F to about 450°F; in one embodiment the temperature ranges from about 320°F to about 385°F; in one embodiment the temperature ranges from about 320°F to about 330°F; in one embodiment the temperature ranges from about 335°F to about 350°F; in one embodiment the temperature ranges from about 355°F to about 365°F; in one embodiment the temperature ranges from about 370°F to about 385°F; the temperature may be about 300°F, about 305°F, about 310°F, about 315°F, about 320°F, about 325°F, about 330°F, about 335°F, about 340°F, about 345°F, about 350°F, about 355°F, about 360°F, about 365°F, about 370°F, about 375°F, about 380°F, about 385°F, about 390°F, about 395°F, about 400°F, about 405°F, about 410°F, about 415°F, about 420°F, about 425°F, about 430°F, about 435°F, about 440°F, about 445°F, or about 450°F. In a preferred embodiment the artificial aging temperature ranges from about 335°F to about 350°F.

[0076] Artificial aging conditions may be applied for between about 1 to about 16 hours; in one embodiment the artificial aging conditions are applied from about 2 to about 12 hours; in one embodiment the artificial aging conditions are applied from about 2 to about 10 hours; in one embodiment the artificial aging conditions are applied from about 4 to about 16 hours; in one embodiment the artificial aging conditions are applied from about 1 to about 6 hours; the artificial aging conditions may be applied for about 1 hour, about 2 hours, about 3 hours, about 4 hours, about 5 hours, about 6 hours, about 7 hours, about 8 hours, about 9 hours, about 10 hours, about 11 hours, about 12 hours, about 13 hours, about 14 hours, about 15 hours, or about 16 hours. In a preferred embodiment the artificial aging conditions are applied for about six hours. In one preferred embodiment, the artificial aging temperature ranges from about 335°F to about 350°F and the conditions are applied for about six hours.

[0077] MATERIAL TESTING - TENSILE PROPERTIES

[0078] Tensile strength may be measured manually or by an automated process.

Automated tests may be performed, for example, on a Zwick Automated Tensile Test Machine.

[0079] Ultimate tensile strength of the extruded and artificially aged aluminum material may be greater than about 310 MPa; in one embodiment the ultimate tensile strength may range from about 310 MPa to about 370 MPa. The ultimate tensile strength may be about 310 MPa, about 315 MPa, about 320 MPa, about 325 MPa, about 330 MPa, about 335 MPa, about 340 MPa, about 345 MPa, about 350 MPa, about 355 MPa, about 360 MPa, about 365 MPa, or about 370 MPa. In comparison, the ultimate tensile strength of an extruded and naturally aged inventive aluminum alloy may range from about 260 MPa to about 295 MPa. In a preferred embodiment the ultimate tensile strength of the extruded and artificially aged aluminum material is greater than about 320 MPa; in a preferred embodiment the ultimate tensile strength of the extruded and artificially aged aluminum material is between about 340 MPa and about 360 MPa; in a preferred embodiment the ultimate tensile strength of the extruded and artificially aged aluminum material is about 350 MPa.

[0080] Yield strength of the extruded and artificially aged aluminum material may be greater than about 275 MPa; in one embodiment the ultimate tensile strength may range from about 285 MPa to about 350 MPa. The ultimate tensile strength may be about 285 MPa, about 290 MPa, about 295 MPa, about 300 MPa, about 305 MPa, about 310 MPa, about 315 MPa, about 320 MPa, about 325 MPa, about 330 MPa, about 335 MPa, about 340 MPa, about 345 MPa, or about 350 MPa. In comparison, the yield strength of an extruded and naturally aged inventive aluminum alloy may range from about 140 MPa to about 180 MPa. In a preferred embodiment the yield strength of the extruded and artificially aged aluminum material is greater than about 320 MPa; in a preferred embodiment the yield strength of the extruded and artificially aged aluminum material is between about 325 MPa and about 335 MPa.

[0081] Elongation of the extruded and artificially aged aluminum material may be less than about 17%; in one embodiment the elongation may range from about 17% to about 7.0%). The elongation may be about 17.0%, about 16.5%, about 16.0%, about 15.5%, about 15.0%, about 14.5%, about 14.0%, about 13.5%, about 13.0%, about 12.5%, about 12.0%, about 11.5%, about 11.0%, about 10.5%, about 10.0%, about 9.5%, about 9.0%, about 8.5%, about 8.0%), about 7.5%, or about 7.0%. In comparison, the elongation of an extruded and naturally aged inventive aluminum alloy may range from about 24.5% to about 21.0%. In a preferred embodiment the elongation of the extruded and artificially aged aluminum material is between about 11.0% and about 14.0%. [0082] MATERIAL TESTING - GRAIN STRUCTURE AND DIE STRUCTURE

[0083] A primary objective of the new chemistry described herein is to achieve fine grain recrystallization. Typically when a grain structure is fully recrystallized with fine grains, elongation properties are better, owing to the slip distances within the grains. The slip distance in smaller grains is significantly reduced when compared to larger grains. Since grains are randomly oriented in three dimensional space, the slip plane orientations are also along random directions.

[0084] When a single grain is under a tensile or compressive load, the slip planes begin to experience a shearing stress. This stress will begin increasing across the grain's slip system and separate the crystals. However, when considering a whole system of randomly oriented grains and slip planes, the matter becomes more complicated. The randomly oriented slip planes will be pulled in different directions causing the material to elongate until one of the slip planes gives way and the piece breaks. With an increased number of grains and the shorter slip distance, the local stresses that develop due to grain boundary incompatibility are lower compared to material with larger grains.

[0085] To aid the alloy with fine grain recrystallization, the amount of dispersoid elements, namely manganese and chromium, are adjusted. In one embodiment, manganese is present in a range of about 0.15 to 0.2 and chromium is present at about 0.03 maximum. Both manganese and chromium add resistance to the recrystallization process, so to form a completely recrystallized grain structure, the elements would have been kept as close to zero as possible. Adding manganese, however, has positive effects on the fracture toughness of the material. The manganese is added in an effort to obtain fine grain recrystallization without negatively affecting the fracture toughness.

[0086] In addition to alloy composition, the extrusion process impacts the alloy's recrystallization properties. Extruder die design may impact the grain structure of the extruded aluminum material. Two aluminum billets run through two different dies at similar speeds and temperatures may yield different grain structures based on die design. Specifically, the choke and number of ports for aluminum to flow through may impact the recrystallization process.

[0087] A choke helps to east the aluminum metal through the due which, in turn, causes less strain energy to be present. The grains will not recrystallize from the as-cast structure if there is not enough energy to do so. Presence of a choke will reduce the strain energy as the metal is pushed through the die and may result in unrecrystallized regions. Absence of choke will increase the strain energy as the metal is pushed through the die and which may result in recrystallized regions.

[0088] The number of ports may also impact the recrystallization process. Additional ports, or larger ports, may permit metal to flow through with greater ease. The extruded aluminum will choose these paths of lower resistance to flow. Increased metal flow will then increase the shear stresses in the metal, and increased shear stresses give the metal more energy to recrystallize.

[0089] Initial billet temperature, extrusion speed, and exit temperatures also impact the recrystallization process and, ultimately, the extruded alloy's strength. Initial billet temperatures should be selected to ensure the material may be extruded easily while achieving the desired strength and grain structure.

[0090] Conductivity of the extruded aluminum material, whether naturally or artificially aged, may be between about 40.0 and 50.0. The conductivity may be about 40.0, about 41.0, about 42.0, about 43.0, about 44.0, about 45.0, about 46.0, about 47.0, about 48.0, about 49.0, or about 50.0. In one preferred embodiment the conductivity is between about 46.0 to about 48.0; in one preferred embodiment the conductivity is about 46.0. [0091] Having now fully described the subject alloys and methods it will be understood by those of ordinary skill in the art that the same can be performed within equivalent ranges of conditions, formulations and other parameters without affecting their scope or any embodiment thereof. All cited patents, patent applications and publications are fully incorporated by reference in their entirety.

[0092] The compositions and methods described herein will be better understood with reference to the following non-limiting examples.

EXAMPLE 1

[0093] CASTING

[0094] A new alloy designated HS6X was given the chemistry limits shown in

Table 1.

Table 1 : Target Chemistry for HS6X.

Values are displayed in weight percents (balance aluminum).

[0095] HS6X was cast into 36 individual logs, each log was 10 inches in diameter and

140 inches long. The cast practice used is shown in Chart 1.

Chart 1 : Temporary cast practice used for HS6X.

[0096] The chemistry of HS6X was taken upon casting in three samples - Al, Bl, and CI . Sample Al was taken from the beginning of the cast, sample B2 from the middle, and sample CI from the end. This data is reported in Table 2.

Table 2: Chemistry of HS6X.

Values are displayed in weight percents (balance aluminum).

[0097] Directly after casting, the microstructure of the logs was not uniform due to the solidification process. In order to uniformly disperse the alloying additions throughout the a-aluminum matrix, the logs were homogenized.

[0098] All of the logs were homogenized at 1045-1065°F for four hours. This elevated temperature provides the alloying elements energy needed to diffuse into the aluminum dendrite arms to develop a more uniform microstructure. EXAMPLE 2

[0099] EXTRUDING

[0100] Two automotive bumper sections were extruded with the HS6X alloy of

Example 1. The sections are shown in FIG. 1 and FIG. 2. Though the sections look similar, there are a few notable differences. Section 569510 has a thinner wall when compared to section 569310. The center and bottom walls of section 569510 also contain regions where the area is not consistent also known as reduced areas. Seven charges of each section were run and all charges were water quenched after leaving the press. Reduced areas are indicated by arrows in FIG. 2.

[0101] Information about the billet temperature, ram speed, and exit temperature was gathered at the press during extrusion. The collected data is displayed in Table 3. Data for each charge was collected when the charge was halfway through completion near the middle of each charge to insure that the speeds and temperatures were constant since breakout speeds and temperatures are lower than what the alloy is capable of. Charges one and two from both sections were determined to be not representative of the whole because they ran slower and had a low exit temperature.

Table 3: Information gathered from press during extrusion process.

4 862 9.9 55 1041

5 867 10.0 59 1039

6 868 10.0 59 1040

7 865 9.9 56 1038

[0102] Water quench rate was found using a quench rate meter with two thermocouples attached to it. Quench rate graphs are displayed in FIG. 3 for section 569310 and FIG. 4 for section 569510.

[0103] The quench rate data for the various charges is located at Table 4.

Table 4: Water Quench Rates for Various Charges

4 10 32.5 53.15

4 12 32.7 40.61

5 2 33.5 485.14

5 4 33.6 322.61

5 6 33.6 251.84

5 8 33.6 224.34

5 10 33.6 202.16

5 12 33.6 60.89

6 2 34 527.33

6 4 34 516.22

6 6 34 417.73

6 8 34 265.08

6 10 34.2 51.31

6 12 34.4 40.96

6 14 34.5 39.84

7 2 34 512.24

7 4 34 426.96

7 6 34 327.35

7 8 34.2 77.65

7 10 34.4 42.36

7 12 34.5 41.53

7 14 34.6 42.1

EXAMPLE 3

[0104] NATURAL AGING

[0105] Natural age testing was performed on section 569310 of Example 2 only. The time periods for this aging process were 0, 1, 2, 3, 5, 10, 15, 20, 25, 30, 35, 40, 50, and 60 days. After each time period was completed, conductivity measurements and tensile tests were used to determine changes in strength. Tensile test locations for section 569310 are displayed in FIG. 5 (indicated by ovals). Since the section of 569310 is mostly symmetrical, the extrusion was cut along the dashed line so that both sides could be utilized for testing. [0106] Natural age conductivity and tensile data for section 569310 is reported in

Table 5. The ultimate tensile strength, yield strength, and elongation as a function of natural age time are displayed in FIG. 7, FIG. 8, and FIG. 9, respectively. Table 5: Natural Age Tensile and Conductivity Data for Section 569310

6-7T 41.19 284.01 23.96 165.20 22.44

41.8

6-7B 39.17 270.08 23.17 159.76 21.20

7-4T 41.17 283.87 24.34 167.82 21.83

41.7

7-4B 39.21 270.35 23.57 162.52 19.93

Day 5 1-6T 40.31 277.94 22.60 155.83 22.10

1-6B 39.35 271.32 21.91 151.07 21.49

2-1T 39.73 273.94 22.75 156.86 23.10

2-1B 39.27 270.77 22.36 154.17 21.57

3-8T 41.08 283.25 23.89 164.72 21.93

3-8B 39.42 271.80 22.84 157.48 21.96

4-4T 40.87 281.80 23.62 162.86 21.57

4-4B 39.94 275.39 22.98 158.45 20.25

6-7T 41.86 288.62 24.59 169.55 22.53

6-7B 40.02 275.94 23.88 164.65 20.12

7-4T 41.93 289.11 24.89 171.62 22.32

7-4B 40.16 276.90 24.16 166.58 20.80

Day 10 1-6T 40.18 277.04 22.29 153.69 23.02

43.0

1-6B 39.96 275.52 22.63 156.03 22.11

2-1T 39.77 274.21 22.63 156.03 23.59

42.7

2-1B 39.86 274.83 23.00 158.59 21.58

3-8T 41.05 283.04 23.60 162.72 22.21

42.1

3-8B 40.63 280.14 23.53 162.24 20.68

4-4T 41.04 282.97 23.63 162.93 21.79

42.2

4-4B 40.81 281.38 23.68 163.27 21.55

6-7T 41.81 288.28 24.54 169.20 21.32

41.6

6-7B 41.29 284.69 24.47 168.72 21.11

7-4T 41.86 288.62 24.91 171.75 21.61

41.6

7-4B 41.33 284.97 24.82 171.13 21.73

Day 15 1-6T 41.5 286.14 23.8 164.10 23.5

42.9

(tested 1-6B 40.5 279.25 20.0 137.90 22.5 by hand) 2-1T 40.9 282.01 23.9 164.79 25.0

42.8

2-1B 40.7 280.63 23.5 162.03 23.0

3-8T 42.1 290.28 25.0 172.38 23.0

42.2

3-8B 40.5 279.25 23.8 164.10 21.5

4-4T 42.1 290.28 24.6 169.62 24.0

42.3

4-4B 41.5 286.14 23.7 163.41 23.0

6-7T 43.0 296.49 24.7 170.31 24.0

41.6

6-7B 41.4 285.45 24.9 171.69 22.0

7-4T 42.8 295.11 25.6 176.51 23.5

41.6

7-4B 41.1 283.38 23.9 164.79 22.0

Day 20 1-6T 40.9 282.01 22.6 155.83 24.0

42.7

(tested 1-6B 40.6 279.94 22.5 155.14 24.5 by hand) 2-1T 40.7 280.63 23.1 159.27 24.5

42.5

2-1B 40.6 279.94 23.2 159.96 23.0

3-8T 41.7 287.52 23.8 164.10 23.0

42.0

3-8B 41.1 283.38 23.4 161.34 22.5

4-4T 41.8 288.21 24.2 166.86 22.5

42.2

4-4B 41.4 285.45 24.3 167.55 22.5 6-7T 42.5 293.04 24.6 169.62 25.0

41.6

6-7B 41.7 287.52 24.9 171.69 23.0

7-4T 42.7 294.42 25.4 175.13 23.0

41.5

7-4B 42.0 289.59 25.4 175.13 22.0

Day 25 1-6T 41.27 284.56 23.58 162.58 23.99

42.7

1-6B 40.50 279.25 22.67 156.31 24.64

2-1T 40.71 280.70 23.68 163.27 25.15

42.8

2-1B 40.45 278.90 23.51 162.10 22.58

3-8T 42.01 289.66 24.65 169.96 22.36

42.3

3-8B 40.47 279.04 23.77 163.89 21.22

4-4T 41.69 287.45 24.56 169.34 24.61

42.3

4-4B 40.92 282.14 23.95 165.14 22.34

6-7T 43.01 296.55 25.64 176.79 22.72

41.4

6-7B 40.75 280.97 24.64 169.89 21.07

7-4T 42.94 296.07 25.88 178.44 22.30

41.9

7-4B 40.81 281.38 25.00 172.38 19.89

Day 30 1-6T 40.85 281.66 22.9 157.90 23.81

42.5

1-6B 40.62 280.07 23.05 158.93 24.74

2-1T 40.57 279.73 23.28 160.52 25.51

42.3

2-1B 40.67 280.42 23.52 162.17 24.73

3-8T 41.68 287.38 24.07 165.96 25.38

41.6

3-8B 41.24 284.35 23.95 165.14 23.69

4-4T 41.51 286.21 24.22 167.00 24.09

42.1

4-4B 41.39 285.38 24.18 166.72 24.37

6-7T 42.45 292.69 25.18 173.62 24.44

41.2

6-7B 41.9 288.90 24.4 168.24 22.28

7-4T 42.35 292.00 25.37 174.93 23.92

41.3

7-4B 41.84 288.49 25.28 174.31 23.26

Day 35 1-6T 41.26 284.49 23.58 162.58 25.5

42.6

1-6B 40.5 279.25 22.95 158.24 26.11

2-1T 40.65 280.28 23.67 163.20 26.14

42.7

2-1B 40.48 279.11 23.44 161.62 24.51

3-8T 42.04 289.87 24.8 171.00 23.98

41.8

3-8B 40.58 279.80 24 165.48 22

4-4T 41.75 287.87 24.59 169.55 25.73

42.1

4-4B 40.88 281.87 24.1 166.17 20.8

6-7T 42.98 296.35 25.67 176.99 26.42

41.3

6-7B 40.94 282.28 24.72 170.44 23.15

7-4T 42.82 295.24 25.87 178.37 23.61

41.6

7-4B 41.11 283.45 25.07 172.86 22.7

Day 40 1-6T 41.4 285.45 22.94 158.17 26

(tested 1-6B 40.93 282.21 22.34 154.03 24 by hand) 2-1T 40.8 281.32 21.4 147.55 25

2-1B 40.8 281.32 23.6 162.72 24

3-8T 42 289.59 24.2 166.86 24

3-8B 42 289.59 23.6 162.72 23

4-4T 42 289.59 24.6 169.62 24

4-4B 41.5 286.14 23.8 164.10 23 6-7T 42.8 295.11 24.9 171.69 25

6-7B 42.3 291.66 24.2 166.86 22

7-4T 43 296.49 23.5 162.03 24

7-4B 41.9 288.90 24.7 170.31 23

Day 50 1-6T 41.61 286.90 24.21 166.93 24.65

1-6B 40.79 281.25 23.21 160.03 23.02

2-1T 41.16 283.80 24.04 165.76 24.07

2-1B 40.84 281.59 24.33 167.76 21.71

3-8T 42.54 293.31 28.21 194.51 21.26

3-8B 41.05 283.04 23.91 164.86 21.54

4-4T 41.88 288.76 24.79 170.93 22.93

4-4B 41.28 284.63 24.76 170.72 20.5

6-7T 43.34 298.83 26.02 179.41 23.59

6-7B 41.4 285.45 25.43 175.34 21.16

7-4T 43.4 299.24 26.31 181.41 22.68

7-4B 41.62 286.97 25.69 177.13 21.52

Day 60 1-6T 0.00 0.00

42.4

1-6B 0.00 0.00

2-1T 0.00 0.00

42.4

2-1B 0.00 0.00

3-8T 0.00 0.00

41.7

3-8B 0.00 0.00

4-4T 0.00 0.00

42.0

4-4B 0.00 0.00

6-7T 0.00 0.00

41.2

6-7B 0.00 0.00

7-4T 0.00 0.00

41.3

7-4B 0.00 0.00

EXAMPLE 4

[0107] ARTIFICIAL AGING

[0108] The aluminum of Example 2 that was not used for natural age testing in

Example 3 was placed in a furnace at 250°F for two hours in order to stabilize it. Stabilizing the metal prevented the loss of artificial aging response (e.g. strength loss) that occurs in 6XXX alloys when they have significant natural aging time. The stabilized pieces could then be used for artificial age testing independent of the effect of varying natural aging times on strength. [0109] Unlike the natural age testing in Example 3, both extruded sections 569310 and 569510 of Example 2 were aged and tested. Tensile test locations for section 569510 are shown in FIG. 6 (indicated by ovals). Since the section of 569510 had reduced areas indicated by arrows along the bottom of one side, both sides could not be used for testing purposes.

[0110] Several artificial aging conditions were used to determine the new alloy's aging kinetics and properties. Table 6 lists the conditions used for the aging process. After the metal was aged, conductivity measurements and tensile tests were used to determine the strength of the material.

Table 6: Aging conditions used for artificial age testing

[01 1 1] Artificial age conductivity and tensile data for section 569310 is reported in

Table 7. The ultimate tensile strength, yield strength, and elongation as a function of age time and temperature for section 569310 are displayed in FIGS. 10-12.

Table 7: Artificial Age Tensile and Conductivity Data for Section 569310

12 3- 1-5T 47.1 51.40 354.40 48.20 332.34 16.00

12 3-1-5B 51.40 354.40 46.20 318.55 14.50

12 4-7-4T 46.1 52.40 361.30 49.00 337.86 14.00

12 4-7-4B 51.40 354.40 48.10 331.65 14.50

12 5-4-4T 46.2 52.40 361.30 48.70 335.79 15.00

12 5-4-4B 51.30 353.71 46.20 318.55 14.00

12 6-4-5T 45.8 52.80 364.06 47.80 329.58 15.00

12 6-4-5B 51.50 355.09 48.70 335.79 14.00

16 2-6-5T 47.4 52.40 361.30 49.20 339.23 14.00

16 2-6-5B 51.60 355.78 47.90 330.27 13.00

16 3- 1-2T 47.5 51.70 356.47 48.70 335.79 14.00

16 3-1-2B 51.10 352.33 48.30 333.03 14.00

16 4-7-1T 46.6 52.80 364.06 49.90 344.06 13.00

16 4-7- lB 51.80 357.16 48.60 335.10 13.00

16 5-4-1T 46.7 52.30 360.61 49.50 341.30 13.00

16 5-4- 1B 51.30 353.71 45.80 315.79 12.50

16 6-4-2T 46.3 53.10 366.12 50.60 348.89 12.00

16 6-4-2B 51.90 357.85 49.60 341.99 12.00

16 7-7-3T 46.1 53.00 365.44 51.00 351.65 12.00

16 7-7-3B 51.90 357.85 49.50 341.30 12.00

338/347 2 1-8-2T 45.5 48.79 336.41 42.61 293.80 14.34

(30-44, 2 1-8-2B 48.85 336.82 42.53 293.24 15.10

46 tested 2 2-8-3T 44.6 49.75 343.03 43.49 299.86 13.82 by hand) 2 2-8-3B 49.61 342.06 43.42 299.38 12.99

2 3-6-3T 44.5 49.82 343.51 43.27 298.35 13.43

2 3-3-6B 49.75 343.03 43.46 299.66 12.96

2 5-7-3T 44.4 50.44 347.78 44.65 307.86 13.08

2 5-7-3B 50.12 345.58 44.42 306.28 1 1.34

2 7-7-1T 44.1 50.99 351.58 45.50 313.72 12.99

2 7-7- 1B 50.53 348.40 45.21 31 1.72 12.85

4 2-6-4T 46.3 50.97 351.44 46.94 323.65 1 1.84

4 2-6-4B 50.83 350.47 46.84 322.96 1 1.80

4 3- 1-2T 46.7 50.28 346.68 46.43 320.13 1 1.17

4 3-1-2B 50.54 348.47 46.55 320.96 12.13

4 4-7-2T 45.8 51.41 354.47 47.53 327.72 1 1.06

4 4-7-2B 51.53 355.30 47.67 328.68 10.32

4 5-4-3T 45.9 51.22 353.16 47.36 326.55 10.63

4 5-4-3B 51.34 353.99 47.58 328.06 1 1.21

4 6-4-4T 45.7 51.77 356.95 48.28 332.89 10.40

4 6-4-4B 51.70 356.47 48.36 333.44 10.29

4 7-7-3T 45.4 51.99 358.47 48.44 333.99 10.51

4 7-7-3B 51.73 356.68 48.55 334.75 10.42

6 1-8-3T 47.3 50.26 346.54 46.94 323.65 1 1.33

6 1-8-3B 50.29 346.75 47.07 324.55 1 1.41

6 2-6-1T 46.8 50.89 350.89 47.55 327.86 1 1.03

6 2-6- lB 50.87 350.75 47.53 327.72 1 1.13

6 3- 1-5T 47.0 50.55 348.54 47.37 326.62 1 1.94

6 3-1-5B 50.46 347.92 47.17 325.24 1 1.23

6 4-7-5T 46.4 51.79 357.09 48.45 334.06 10.32

6 4-7-5B 51.80 357.16 48.40 333.72 14.00

6 5-4-5T 46.4 51.80 357.16 48.40 333.72 13.00

6 5-4-5B 51.80 357.16 48.80 336.48 12.00

6 6-4-2T 46.1 52.30 360.61 44.20 304.76 12.00 6-4-2B 52.20 359.92 49.50 341.30 1 1.00

2-6-3T 47.2 51.40 354.40 48.50 334.41 1 1.00

2-6-3B 51.10 352.33 48.00 330.96 1 1.00

3- 1-3T 47.4 50.40 347.51 47.40 326.82 13.00

3-1-3B 50.70 349.58 47.40 326.82 12.00

4-7-3T 46.9 52.00 358.54 48.70 335.79 12.00

4-7-3B 51.70 356.47 48.90 337.17 12.00

5-4-2T 46.8 51.50 355.09 46.30 319.24 12.00

5-4-2B 51.80 357.16 47.80 329.58 1 1.50

6-4-1T 46.6 52.30 360.61 49.70 342.68 1 1.00

6-4- IB 52.30 360.61 49.90 344.06 1 1.50

7-7-4T 46.5 52.29 360.54 49.91 344.13 8.87

7-7-4B 52.20 359.92 49.30 339.92 10.50

1-8-2T 48.1 50.02 344.89 47.32 326.27 1 1.95

1-8-2B 50.05 345.09 47.19 325.38 10.24

2-6-1T 48.0 50.42 347.65 47.64 328.48 1 1.12

2-6- 1B 50.59 348.82 47.63 328.41 10.69

3- 1-2T 47.9 49.97 344.54 47.01 324.13 1 1.70

3-1-2B 50.06 345.16 46.87 323.17 1 1.36

4-7-1T 47.6 51.48 354.95 48.66 335.51 8.89

4-7- 1B 50.96 351.37 48.08 331.51 9.49

5-4-5T 47.5 51.20 353.02 48.36 333.44 10.03

5-4-5B 50.72 349.71 47.83 329.79 9.91

6-4-1T 46.9 51.72 356.61 49.27 339.72 8.24

6-4- IB 51.06 352.06 48.06 331.37 8.99

7-7-2T 46.9 52.1 1 359.30 49.92 344.20 9.54

7-7-2B 51.19 352.96 49.37 340.41 8.82

1-8-1T 48.5 49.72 342.82 47.03 324.27 1 1.23

1-8- 1B 49.60 341.99 46.83 322.89 10.63

2-6-1T 48.1 49.99 344.68 47.28 326.00 1 1.28

2-6- 1B 50.12 345.58 47.29 326.06 10.26

3- 1-lT 47.9 49.58 341.85 46.70 322.00 12.29

3-1- lB 49.58 341.85 46.43 320.13 9.87

4-7-2T 47.4 51.07 352.13 48.50 334.41 8.68

4-7-2B 50.61 348.96 47.89 330.20 8.91

5-4-5T 47.2 50.75 349.92 48.07 331.44 10.07

5-4-5B 50.32 346.96 47.57 328.00 10.32

6-4-4T 47.2 51.48 354.95 49.07 338.34 8.73

6-4-4B 50.79 350.20 48.46 334.13 8.77

7-7-5T 47.0 51.75 356.82 49.63 342.20 7.79

7-7-5B 50.83 350.47 49.11 338.61 7.79

2-6-5T 46.7 50.66 349.30 47.18 325.31 12.18

2-6-5B 50.47 347.99 46.70 322.00 1 1.10

3- 1-4T 46.7 50.09 345.37 46.36 319.65 13.05

3-1-4B 49.92 344.20 46.02 317.31 1 1.00

4-7-5T 46.2 51.62 355.92 48.16 332.06 9.98

4-7-5B 50.66 349.30 46.63 321.51 1 1.03

5-4-3T 46.1 51.09 352.27 47.54 327.79 1 1.20

5-4-3B 50.49 348.13 46.74 322.27 10.97

6-4-2T 45.9 51.95 358.20 48.74 336.06 10.03

6-4-2B 50.79 350.20 47.84 329.86 10.12

7-7-3T 45.6 52.07 359.02 48.95 337.51 9.56

7-7-3B 50.92 351.09 48.07 331.44 1 1.51 1-8-4T 48.1 50.02 344.89 47.20 325.44 1 1.21

1-8-4B 49.89 343.99 46.98 323.93 10.82

2-6-3T 47.6 50.38 347.37 47.63 328.41 10.75

2-6-3B 50.42 347.65 47.42 326.96 10.56

3- 1-4T 47.6 50.06 345.16 47.09 324.69 1 1.35

3-1-4B 49.88 343.92 46.89 323.31 10.30

4-7-5T 47.0 51.58 355.64 48.83 336.68 9.38

4-7-5B 50.80 350.27 47.95 330.62 8.79

5-4-4T 47.1 51.19 352.96 48.38 333.58 1 1.13

5-4-4B 50.48 348.06 47.11 324.82 9.59

6-4-3T 46.7 51.94 358.13 49.43 340.82 9.31

6-4-3B 50.93 351.16 48.51 334.48 9.46

7-7-4T 46.6 52.15 359.57 49.94 344.34 7.63

7-7-4B 51.1 1 352.40 49.47 341.10 8.26

1-8-2T 48.3 49.59 341.92 46.96 323.79 10.83

1-8-2B 49.35 340.27 46.68 321.86 10.03

2-6-2T 48.0 49.77 343.16 47.16 325.17 10.30

2-6-2B 49.67 342.47 46.63 321.51 9.69

3- 1-5T 47.9 49.26 339.65 46.48 320.48 1 1.19

3-1-5B 49.17 339.03 46.16 318.27 10.24

4-7-3T 47.5 50.82 350.40 48.27 332.82 8.91

4-7-3B 50.09 345.37 47.39 326.75 9.73

5-4-3T 47.5 50.43 347.71 47.80 329.58 9.08

5-4-3B 49.83 343.58 47.35 326.48 8.65

6-4-5T 47.2 51.22 353.16 48.92 337.30 8.33

6-4-5B 49.94 344.34 48.32 333.17 9.60

7-7-1T 47.1 51.51 355.16 49.40 340.61 7.76

7-7- 1B 50.65 349.23 48.95 337.51 9.02

1-8-1T 48.0 48.84 336.75 46.08 317.72 9.94

1-8- 1B 48.64 335.37 45.83 316.00 9.80

2-6-3T 48.3 48.93 337.37 46.23 318.76 10.42

2-6-3B 48.94 337.44 46.25 318.89 9.13

3- 1-3T 48.2 48.66 335.51 45.80 315.79 1 1.70

3-1-3B 48.49 334.34 45.43 313.24 9.73

4-7-2T 47.8 50.19 346.06 47.54 327.79 9.17

4-7-2B 49.48 341.16 46.73 322.20 9.10

5-4-2T 47.7 49.60 341.99 46.96 323.79 9.66

5-4-2B 49.13 338.75 46.35 319.58 8.99

6-4-4T 47.6 50.39 347.44 47.98 330.82 8.80

6-4-4B 49.56 341.72 47.30 326.13 8.95

7-7-1T 47.4 50.90 350.96 48.69 335.72 8.57

7-7- 1B 49.98 344.61 48.01 331.03 7.80

1-8-3T 49.0 47.50 327.51 44.64 307.79 10.01

1-8-3B 47.60 328.20 44.77 308.69 9.56

2-6-5T 48.3 48.22 332.48 45.37 312.83 9.41

2-6-5B 48.17 332.13 45.35 312.69 10.04

3- 1-4T 48.1 47.46 327.24 44.43 306.34 10.84

3-1-4B 47.75 329.24 44.73 308.41 10.00

4-7-3T 48.0 48.81 336.54 45.97 316.96 8.91

4-7-3B 48.88 337.03 46.12 318.00 8.56

5-4-4T 47.9 48.55 334.75 45.68 314.96 9.18

5-4-4B 48.54 334.68 45.76 315.52 10.37

6-4-3T 47.8 48.95 337.51 46.46 320.34 9.59 6-4-3B 49.13 338.75 46.79 322.62 9.15

7-7-5T 47.8 49.38 340.48 47.07 324.55 8.66

7-7-5B 49.53 341.51 47.65 328.55 7.80

2-6-1T 46.4 50.08 345.30 46.75 322.34 1 1.31

2-6- 1B 49.73 342.89 46.46 320.34 1 1.12

3- 1-lT 46.9 49.27 339.72 45.86 316.20 1 1.66

3-1- lB 49.30 339.92 45.86 316.20 10.29

5-4-1T 46.3 50.32 346.96 46.85 323.03 10.71

5-4- 1B 50.14 345.72 46.75 322.34 10.79

4-7-2T 46.2 50.59 348.82 47.17 325.24 10.33

4-7-2B 50.55 348.54 46.66 321.72 10.55

6-4-5T 46.3 51.00 351.65 48.42 333.86 9.80

6-4-5B 50.73 349.78 48.32 333.17 9.61

7-7-1T 46.3 51.48 354.95 48.85 336.82 9.57

7-7- 1B 51.02 351.78 48.74 336.06 8.86

1-8-1T 47.8 49.14 338.82 46.24 318.82 1 1.32

1-8- 1B 48.97 337.65 46.18 318.41 1 1.04

2-6-2T 47.3 49.87 343.85 47.07 324.55 10.44

2-6-2B 49.41 340.68 47.10 324.75 10.38

3- 1-lT 47.3 49.19 339.17 46.46 320.34 10.77

3-1- lB 49.15 338.89 46.28 319.10 10.28

4-7-1T 47.0 50.60 348.89 47.73 329.10 8.99

4-7- 1B 50.40 347.51 47.73 329.10 9.15

5-4-4T 47.1 50.20 346.13 47.39 326.75 9.48

5-4-4B 50.13 345.65 47.36 326.55 10.50

6-4-2T 46.9 50.69 349.51 48.26 332.75 9.33

6-4-2B 50.50 348.20 48.34 333.30 9.29

7-7-5T 46.8 51.08 352.20 48.91 337.23 9.18

7-7-5B 50.72 349.71 48.99 337.79 8.78

1-8-4T 48.3 48.67 335.58 46.02 317.31 10.69

1-8-4B 48.52 334.55 45.70 315.10 9.98

2-6-5T 47.5 49.48 341.16 46.76 322.41 9.73

2-6-5B 49.23 339.44 46.53 320.82 9.99

3- 1-2T 47.5 48.64 335.37 45.77 315.58 10.39

3-1-2B 48.68 335.65 45.63 314.62 9.93

4-7-4T 47.4 50.06 345.16 47.59 328.13 9.09

4-7-4B 50.00 344.75 47.38 326.69 9.63

5-4-2T 47.3 49.63 342.20 46.92 323.51 9.55

5-4-2B 49.66 342.41 46.98 323.93 10.41

6-4-1T 47.3 50.08 345.30 47.60 328.20 9.06

6-4- IB 49.92 344.20 47.85 329.93 9.83

7-7-2T 47.0 50.43 347.71 48.24 332.61 9.52

7-7-2B 50.10 345.44 48.36 333.44 8.39

1-8-1T 48.6 47.88 330.13 45.01 310.34 10.87

1-8- 1B 47.87 330.06 45.06 310.69 10.04

2-6-3T 47.9 48.69 335.72 45.85 316.14 9.34

2-6-3B 48.48 334.27 45.65 314.76 9.13

3- 1-5T 47.7 47.98 330.82 45.05 310.62 10.08

3-1-5B 48.14 331.93 45.28 312.21 10.14

4-7-1T 47.6 49.48 341.16 46.90 323.38 8.69

4-7- 1B 49.41 340.68 46.72 322.13 9.38

5-4-5T 47.5 49.17 339.03 46.34 319.51 10.09

5-4-5B 49.02 337.99 46.34 319.51 9.27 4 6-4-3T 47.4 49.43 340.82 46.57 321.10 9.13

4 6-4-3B 49.33 340.13 47.07 324.55 9.07

4 7-7-2T 47.3 49.81 343.44 47.60 328.20 9.00

4 7-7-2B 49.60 341.99 47.78 329.44 8.19

5 1-8-2T 48.8 47.22 325.58 44.29 305.38 10.52

5 1-8-2B 47.14 325.03 44.31 305.52 10.32

5 2-6-2T 48.1 47.78 329.44 44.80 308.90 9.65

5 2-6-2B 47.53 327.72 44.63 307.72 10.16

5 3- 1-3T 48.1 47.27 325.93 44.15 304.41 10.36

5 3-1-3B 47.18 325.31 44.07 303.86 10.33

5 4-7-5T 47.9 48.74 336.06 45.83 316.00 9.15

5 4-7-5B 48.63 335.30 45.84 316.07 9.26

5 5-4-1T 47.8 48.09 331.58 45.15 31 1.31 9.46

5 5-4- 1B 47.88 330.13 44.91 309.65 9.63

5 6-4-4T 47.7 48.44 333.99 45.75 315.45 9.67

5 6-4-4B 48.27 332.82 45.82 315.93 10.02

5 7-7-4T 47.7 48.81 336.54 46.35 319.58 8.53

5 7-7-4B 48.60 335.10 46.61 321.38 8.25

6 1-8-4T 49.0 45.85 316.14 42.62 293.86 10.98

6 1-8-4B 45.70 315.10 42.66 294.14 9.66

6 2-6-4T 48.4 46.69 321.93 43.49 299.86 9.87

6 2-6-4B 46.40 319.93 43.30 298.55 9.48

6 3- 1-4T 48.2 45.76 315.52 42.38 292.21 10.71

6 3-1-4B 45.90 316.48 42.70 294.42 9.82

6 4-7-4T 48.0 47.06 324.48 43.80 302.00 8.80

6 4-7-4B 47.23 325.65 44.35 305.79 9.37

6 5-4-3T 48.0 46.90 323.38 43.67 301.10 10.10

6 5-4-3B 46.93 323.58 43.84 302.28 9.10

6 6-4-5T 47.8 47.52 327.65 44.58 307.38 9.70

6 6-4-5B 47.35 326.48 44.72 308.34 8.97

6 7-7-3T 47.7 47.88 330.13 45.14 31 1.24 9.01

6 7-7-3B 47.49 327.44 45.08 310.83 9.25

[0112] Artificial age conductivity and tensile data for section 56951 is reported in

Table 8. The ultimate tensile strength, yield strength, and elongation as a function of age time and temperature for section 569510 are displayed in FIG. 13, FIG. 14, and FIG. 15, respectively. Table 8: Artificial Age Tensile and Conductivity Data for Section 569510

6- 1-3T 50 344.8 42.87 295.6 15.35

43.9

6-1-3B 50.22 346.3 43.65 301 15.31

7- 1-2T 49.9 344.1 42.96 296.2 17.14

43.9

7-1-2B 50.1 1 345.5 43.74 301.6 16.04

1-10-4T 48.7 335.8 44.42 306.3 9.6

45.0

1-10-4B 49.91 344.1 45.32 312.5 12.1

2-5-2T 48.57 334.9 44.78 308.8 1 1.85

44.9

2-5-2B 49.64 342.3 46.23 318.8 9.78

3-5-2T 51.32 353.9 46.71 322.1 13.15

45.3

3-5-2B 51.65 356.1 47.2 325.4 12.67

4-10-2T 52.37 361.1 48.07 331.4 12.85

45.2

4-10-2B 52.67 363.2 48.56 334.8 12.76

5-5-1T 52 358.5 47.41 326.9 12.85

45.0

5-5- 1B 52.35 361 47.99 330.9 12.89

6-10-2T 52.72 363.5 46.67 321.8 12.98

44.7

6-10-2B 53.06 365.8 48.76 336.2 12.9

7-5-2T 52.17 359.7 47.6 328.2 12.34

44.8

7-5-2B 52.4 361.3 32.97 227.3 12.84

1-10-4T 49.35 340.3 46.65 321.7 7.16

46.0

1-10-4B 50.5 348.2 47.44 327.1 8.08

2- 1-4T 49.03 338.1 46.14 318.1 10.29

46.1

2-1-4B 50.39 347.4 47.62 328.3 10.26

3-5-1T 52 358.5 47.37 326.6 12.06

46.1

3-5- 1B 52.09 359.2 49.12 338.7 12.08

4-5-1T 52.64 363 49.5 341.3 1 1.59

46.2

4-5- 1B 52.73 363.6 49.68 342.5 1 1.34

5-10-3T 52.99 365.4 49.98 344.6 10.86

45.7

5-10-3B 53.31 367.6 50.88 350.8 10.87

6-5-1T 53.63 369.8 50.52 348.3 9.91

45.7

6-5- 1B 53.44 368.5 50.49 348.1 10.94

7-10-2T 53.51 369 50.47 348 10.51

45.7

7-10-2B 53.25 367.2 50.21 346.2 1 1.37

1-10-5T 50.19 346.1 47.15 325.1 8.32

46.7

1-10-5B 51.21 353.1 48.24 332.6 9.88

2-5-2T 49.8 343.4 47.62 328.3 8.45

46.4

2-5-2B 50.74 349.9 48.69 335.7 8.05

3-5-1T 52.34 360.9 49.52 341.4 10.82

46.7

3-5- 1B 52.55 362.3 49.59 341.9 1 1.19

4-10-lT 53.58 369.4 51.22 353.2 9.24

46.8

4-10-lB 53.42 368.3 51.17 352.8 10.84

5- 1-lT 52.5 362 50.08 345.3 10.8

46.9

5-1- lB 52.52 362.1 50.16 345.9 10.98

6- 1-2T 53.03 365.6 50.71 349.6 10.71

46.7

6-1-2B 53.05 365.8 50.74 349.9 10.26

7- 1-lT 52.76 363.8 50.31 346.9 10.83

46.9

7-1- lB 52.5 362 50.14 345.7 10.91

1-5-2T 47.58 328.1 41.76 287.9 12.23

44.1

1-5-2B 49.48 341.2 43.67 301.1 14.7

2-5-3T 46.88 323.2 41.76 287.9 13.31

43.7

2-5-3B 48.18 332.2 43.27 298.3 10.59

3-10-lT 49.63 342.2 43.9 302.7 13.4

43.8

3-10-lB 49.78 343.2 43.59 300.6 14.62

4- 1-2T 44.3 49.81 343.4 44.45 306.5 13.64 4-1-2B 49.91 344.1 44.85 309.2 14.56

5-5-5T 50.23 346.3 44.18 304.6 13.6

43.7

5-5-5B 50.37 347.3 45.05 310.6 13.85

6-5-4T 50.9 351 44.94 309.9 13.53

43.5

6-5-4B 51.01 351.7 45.63 314.6 14.24

7- 1-4T 50.41 347.6 44.94 309.9 14.17

44.1

7-1-4B 50.41 347.6 10.45 72.05 14.63

1-5-5T 49.2 339.2 45.25 312 1 1.45

45.2

1-5-5B 50.33 347 46.31 319.3 10.01

2- 1-2T 48.05 331.3 44.68 308.1 10.45

45.5

2-1-2B 49.38 340.5 46.23 318.8 9.15

3-5-2T 50.92 351.1 46.65 321.7 12.62

45.2

3-5-2B 51.06 352.1 47.2 325.4 12.87

4-5-4T 51.57 355.6 47.63 328.4 12.32

54.3

4-5-4B 51.62 355.9 48.26 332.8 12.35

5- 1-3T 51.3 353.7 47.35 326.5 13.09

45.1

5-1-3B 51.14 352.6 47.48 327.4 12.54

6- 1-5T 51.89 357.8 45.16 31 1.4 12.82

45.0

6-1-5B 51.78 357 48.07 331.4 12.58

7-5-2T 51.85 357.5 47.72 329 1 1.93

44.9

7-5-2B 51.93 358.1 44.44 306.4 1 1.79

1-10-lT 49.14 338.8 46.01 317.2 8.01

46.0

1-10-lB 50.94 351.2 47.38 326.7 10.81

2- 1-lT 48.48 334.3 46.01 317.2 8.97

46.2

2-1- lB 49.43 340.8 47.02 324.2 8.22

3-10-lT 52.2 359.9 49.27 339.7 10.65

46.0

3-10-lB 52.13 359.4 49.71 342.8 10.61

4- 1-4T 51.68 356.3 49.05 338.2 1 1.35

46.3

4-1-4B 51.56 355.5 49.03 338.1 10.97

5-10-lT 52.83 364.3 50.2 346.1 8.78

46.0

5-10-lB 52.93 365 50.54 348.5 10.1

6-5-4T 53 365.4 50.62 349 10.29

46.0

6-5-4B 52.88 364.6 36.49 251.6 9.97

7-10-3T 52.88 364.6 50.88 350.8 8.64

46.1

7-10-3B 52.87 364.5 50.89 350.9 10.36

1-5-3T 49.91 344.1 47.26 325.9 10.72

46.8

1-5-3B 50.82 350.4 47.65 328.5 10.14

2-5-4T 49.44 340.9 47.76 329.3 8.72

46.3

2-5-4B 50.38 347.4 48.62 335.2 9.81

3- 1-2T 51.2 353 48.87 337 10.34

46.5

3-1-2B 51.14 352.6 48.74 336.1 1 1.27

4-5-1T 52.05 358.9 49.59 341.9 10.2

46.6

4-5- 1B 51.94 358.1 49.88 343.9 10.86

5- 1-3T 51.76 356.9 49.6 342 1 1

46.5

5-1-3B 51.64 356.1 49.54 341.6 10.53

6-10-3T 53.22 367 51.55 355.4 9.8

46.4

6-10-3B 53.23 367 50.91 351 8.93

7- 1-3T 52.1 359.2 50.16 345.9 9.32

46.5

7-1-3B 51.82 357.3 49.87 343.9 9.89

1-10-3T 49.65 342.3 47.6 328.2 8.39

46.7

1-10-3B 50.81 350.3 48.52 334.5 10.2

2-10-4T 50.25 346.5 48.88 337 7.05

46.3

2-10-4B 51.1 1 352.4 48.91 337.2 10.25 3- 1-2T 50.95 351.3 48.84 336.8 9.97

46.6

3-1-2B 52.03 358.7 50.11 345.5 9.97

4-5-5T 51.83 357.4 50.11 345.5 9.89

46.6

4-5-5B 52.24 360.2 50.3 346.8 8.98

5-5-2T 52.05 358.9 50.2 346.1 9.35

46.4

5-5-2B 53.17 366.6 51.59 355.7 6.72

6-10-5T 53.05 365.8 51.65 356.1 8.1 1

46.6

6-10-5B 52.51 362.1 50.78 350.1 9.09

7-5-5T 52.14 359.5 50.48 348.1 8.66

46.8

7-5-5B 49.46 341 47.8 329.6 6.02

1-10-3T 50.51 348.3 48.39 333.6 9.72

47.3

1-10-3B 48.92 337.3 47.68 328.8 6.88

2-5-1T 49.49 341.2 48.07 331.4 7.24

46.9

2-5- 1B 50.77 350.1 48.84 336.8 10.28

3- 1-lT 50.52 348.3 48.6 335.1 9.96

47.0

3-1- lB 51.91 357.9 50.32 347 9.13

4-10-5T 51.6 355.8 50.15 345.8 9.37

47.1

4-10-5B 51.85 357.5 50.26 346.5 9.02

5-5-3T 51.63 356 49.9 344.1 9.35

46.8

5-5-3B 52.61 362.7 51.29 353.6 7.51

6-5-3T 52.33 360.8 51.1 352.3 8.22

46.6

6-5-3B 52.03 358.7 50.62 349 8.06

7-5-1T 51.64 356.1 50.09 345.4 8.59

46.8

7-5- 1B 49.89 344 48.34 333.3 7.68

1-10-2T 48.49 334.3 45.16 31 1.4 9.67

46.2

1-10-2B 49.99 344.7 46.6 321.3 9.97

2- 1-2T 47.3 326.1 44.66 307.9 7.91

46.5

2-1-2B 48.71 335.9 46.13 318.1 8.37

3- 1-5T 50.46 347.9 47.16 325.2 10.68

46.2

3-1-5B 50.52 348.3 47.47 327.3 1 1.04

4- 1-5T 50.88 350.8 47.92 330.4 1 1.78

46.4

4-1-5B 50.93 351.2 48.19 332.3 10.85

5-10-4T 51.51 355.2 48.45 334.1 10.61

45.9

5-10-4B 51.69 356.4 48.9 337.2 10.62

6-5-1T 52.12 359.4 49.13 338.8 10.61

45.8

6-5- 1B 52.09 359.2 49.41 340.7 1 1.32

7-5-3T 51.8 357.2 49.07 338.3 10.65

46.1

7-5-3B 51.83 357.4 49.28 339.8 10.26

1-5-4T 49.23 339.4 46.8 322.7 9.8

47.4

1-5-4B 50.16 345.9 47.51 327.6 10.36

2- 1-4T 48.01 331 46.47 320.4 7.2

47.0

2-1-4B 49.12 338.7 47.24 325.7 7.01

3-10-4T 51.8 357.2 49.72 342.8 8.61

47.1

3-10-4B 51.73 356.7 49.77 343.2 9.67

4- 1-5T 50.98 351.5 49.02 338 9.67

47.0

4-1-5B 50.94 351.2 49.02 338 9.57

5-5-1T 51.82 357.3 49.97 344.5 9.16

46.8

5-5- 1B 51.66 356.2 49.85 343.7 9.86

6-5-5T 52.46 361.7 50.88 350.8 7.99

46.7

6-5-5B 52.31 360.7 51.01 351.7 8.22

7-5-3T 51.91 357.9 50.21 346.2 8.61

46.9

7-5-3B 51.67 356.3 50.08 345.3 9.81

1-10-lT 47.5 48.94 337.4 47.35 326.5 7.74 1-10-lB 49.89 344 47.82 329.7 9.65

2-5-1T 48.41 333.8 47.17 325.2 7.72

47.1

2-5- 1B 48.99 337.8 46.83 322.9 6.21

3- 1-4T 50.33 347 48.53 334.6 9.52

47.2

3-1-4B 50.18 346 48.43 333.9 9.8

4-10-3T 51.45 354.7 49.99 344.7 8.32

47.3

4-10-3B 51.13 352.5 49.73 342.9 8.55

5-10-5T 51.63 356 50.36 347.2 7.74

47.3

5-10-5B 51.36 354.1 50.17 345.9 8.91

6- 1-3T 51.15 352.7 49.7 342.7 8.76

47.1

6-1-3B 51 351.6 49.59 341.9 9.1 1

7- 1-5T 50.9 351 49.28 339.8 9.03

47.2

7-1-5B 50.72 349.7 49.23 339.4 8.82

1-5-1T 48.09 331.6 45.79 315.7 8.1

48.1

1-5- 1B 48.81 336.5 46.24 318.8 9.94

2-5-5T 48.22 332.5 47.17 325.2 6.49

47.5

2-5-5B 48.92 337.3 47.51 327.6 7.04

3-5-4T 50.16 345.9 48.46 334.1 8.66

47.6

3-5-4B 50.13 345.6 48.41 333.8 8.69

4-10-5T 50.88 350.8 49.62 342.1 8.2

47.7

4-10-5B 50.65 349.2 42.33 291.9 8.86

5-5-3T 50.96 351.4 49.49 341.2 8.55

47.4

5-5-3B 50.68 349.4 49.2 339.2 9.04

6- 1-lT 50.67 349.4 49.29 339.9 8.78

47.6

6-1- lB 50.49 348.1 49.07 338.3 8.81

7- 1-4T 50.45 347.9 48.92 337.3 9.01

47.5

7-1-4B 50.25 346.5 48.76 336.2 8.07

1-5-2T 47.72 329 45.38 312.9 9.55

48.2

1-5-2B 48.08 331.5 45.32 312.5 9.06

2-10-5T 48.64 335.4 47.55 327.9 7.7

47.5

2-10-5B 48.8 336.5 46.15 318.2 7.84

3-10-2T 50.73 349.8 49.13 338.8 6.64

47.7

3-10-2B 50.42 347.6 48.91 337.2 8.52

4- 1-3T 49.16 339 47.43 327 9.29

47.6

4-1-3B 49.02 338 47.32 326.3 8.9

5-10-5T 50.73 349.8 49.49 341.2 7.98

47.7

5-10-5B 50.5 348.2 49.22 339.4 7.94

6- 1-4T 50.17 345.9 48.77 336.3 8.71

47.6

6-1-4B 49.91 344.1 48.51 334.5 8.38

7- 1-5T 49.91 344.1 48.41 333.8 8.56

47.7

7-1-5B 49.58 341.9 48.04 331.2 8.5

1-5-3T 46 48.34 333.3 45.33 312.6 9.47

1-5-1T 46.2 48.36 333.4 45.19 31 1.6 10.18

2- 1-3T 47.02 324.2 44.78 308.8 7.41

45.9

2-1-3B 48.25 332.7 45.72 315.2 7.68

3-5-3T 50.63 349.1 47.79 329.5 9.89

46.2

3-5-3B 50.56 348.6 47.85 329.9 10.58

4- 1-3T 50.37 347.3 47.89 330.2 10.8

46.2

4-1-3B 50.31 346.9 47.75 329.2 1 1.01

5-5-5T 51.37 354.2 48.63 335.3 10.59

45.9

5-5-5B 51.31 353.8 48.8 336.5 10.78

6- 1-4T 51.36 354.1 48.94 337.4 10.34

46

6-1-4B 51.41 354.5 49.14 338.8 10.69 7- 1-2T 51.1 1 352.4 48.65 335.4 10.32

46.3

7-1-2B 50.9 351 48.52 334.5 9.99

1-5-4T 48.55 334.8 46.32 319.4 7.73

47.6

1-5-4B 49.42 340.8 46.87 323.2 7.83

2-5-3T 48.35 333.4 47.06 324.5 7.44

46.9

2-5-3B 48.82 336.6 47.44 327.1 7.51

3- 1-5T 50.34 347.1 48.29 333 9.1 1

46.9

3-1-5B 50.18 346 48.2 332.3 10.33

4- 1-2T 50.43 347.7 48.6 335.1 9.03

46.9

4-1-2B 50.34 347.1 48.5 334.4 9.75

5- 1-4T 50.92 351.1 49.1 338.5 9.72

47.1

5-1-4B 50.76 350 49.02 338 9.76

6-10-4T 52.44 361.6 50.86 350.7 7.5

46.7

6-10-4B 52.37 361.1 50.97 351.4 8.91

7-10-5T 52.16 359.6 50.95 351.3 7.14

46.8

7-10-5B 51.98 358.4 50.65 349.2 8.97

1-10-5T 48.32 333.2 46.76 322.4 5.61

47.8

1-10-5B 49.45 341 47.47 327.3 7.56

2-5-5T 48.23 332.5 47.09 324.7 6.59

47.3

2-5-5B 49.1 1 338.6 47.59 328.1 6.98

3- 1-3T 49.94 344.3 48.17 332.1 9.05

47.5

3-1-3B 49.88 343.9 48.1 331.6 9.25

4-5-2T 50.59 348.8 49 337.9 9.07

47.4

4-5-2B 50.4 347.5 48.82 336.6 8.63

5-10-2T 51.59 355.7 50.3 346.8 7.4

47.3

5-10-2B 51.42 354.5 50.13 345.6 9.14

6-5-5T 51.61 355.9 50.4 347.5 7.29

46.9

6-5-5B 51.38 354.3 50.2 346.1 8.68

7- 1-3T 50.55 348.5 49.04 338.1 9.09

46.8

7-1-3B 50.22 346.3 48.73 336 8.82

1-5-1T 47.86 330 45.56 314.1 8.78

47.7

1-5- 1B 48.35 333.4 45.71 315.2 8.18

2-5-4T 48.07 331.4 46.98 323.9 7.98

47.2

2-5-4B 48.4 333.7 46.98 323.9 7.35

3-10-3T 50.53 348.4 49.07 338.3 6.58

47.4

3-10-3B 50.32 347 48.81 336.5 8.26

4- 1-lT 49.25 339.6 47.54 327.8 9.36

47.4

4-1- lB 49.1 338.5 47.42 327 9.36

5- 1-lT 49.76 343.1 48.2 332.3 8.98

47.5

5-1- lB 49.39 340.5 47.8 329.6 8.88

6-10-2T 51.65 356.1 50.67 349.4 6.53

47.2

6-10-2B 51.16 352.7 49.96 344.5 7.61

7- 1-lT 49.75 343 48.25 332.7 8.42

47.3

7-1- lB 49.35 340.3 47.79 329.5 8.78

1-10-2T 47.52 327.7 46.2 318.5 5.95

47.8

1-10-2B 48.31 333.1 46.26 319 7.63

2-10-2T 48.28 332.9 47.14 325 7.88

47.3

2-10-2B 48.56 334.8 47.19 325.4 6.79

3-10-2T 50.26 346.5 48.73 336 6.71

47.6

3-10-2B 49.97 344.5 48.46 334.1 8.42

4-5-3T 49.71 342.8 48.18 332.2 8.49

47.5

4-5-3B 49.29 339.9 47.68 328.8 8.17

5-10-lT 47.4 50.65 349.2 49.4 340.6 6.06 5 5-10-lB 50.51 348.3 49.14 338.8 7.82

5 6- 1-5T 49.92 344.2 48.52 334.5 8.3

47.5

5 6-1-5B 49.66 342.4 48.24 332.6 8.18

5 7-5-5T 50.04 345 48.66 335.5 7.72

47.4

5 7-5-5B 49.58 341.9 48.13 331.9 7.88

6 1-5-3T 46.1 1 317.9 43.65 301 7.99

48.3

6 1-5-3B 46.29 319.2 43.16 297.6 8.65

6 2-10-3T 47.32 326.3 46 317.2 7.18

47.6

6 2-10-3B 47.4 326.8 45.96 316.9 6.65

6 3-10-3T 49.2 339.2 47.58 328.1 7.54

47.9

6 3-10-3B 48.76 336.2 47.13 325 8.25

6 4-10-4T 49.09 338.5 47.56 327.9 8.78

48

6 4-10-4B 48.81 336.5 47.18 325.3 8.47

6 5-5-4T 49.12 338.7 47.52 327.7 8.39

47.7

6 5-5-4B 48.74 336.1 47.08 324.6 7.81

6 6-10-5T 50.64 349.2 49.14 338.8 6.24

47.6

6 6-10-5B 50.19 346.1 48.91 337.2 7.7

6 7-10-4T 50.09 345.4 48.83 336.7 6.92

47.7

6 7-10-4B 49.57 341.8 48.17 332.1 7.99

[0113] The tensile properties for this section versus that of section 569310 show that there is a little difference between ultimate tensile strength and yield strength with the elongation being slightly different.

[0114] The artificial age practices that called for higher temperatures and shorter times displayed over-aging. Where section 569310 had both its tensile and yield strength drop off, section 569510 had only the tensile strength drop with the yield strength lingering at elevated strengths which is not common. Upon inspecting the collected data in Table 5 and 7, it was determined that the cause of the out-of-the-ordinary yield strengths was due to the sampling locations. Section 569310 had the same location from every charge tested while section 569510 was more randomized - sampling from front, middle, and rear sections rather than using the same location for every condition.

[0115] Despite section 569510 being fully recrystallized, section 569310 experienced better elongation. This could be due to the unrecrystallized grain structure in the center wall. In other words, there were not enough coarse recrystallized grains to interfere with the elongation. The inventive chemistry described here was created to avoid the issue of poor elongation resulting from coarse grains along the edges, but due to the die design of section 569310, the unrecrystallized portions were unavoidable with the extrusion process used.

EXAMPLE 5

[0116] METALLURGICAL RESULTS - INGOT

[0117] Sample slices were taken from one log of Example 1 after homogenization for characterization purposes. One slice was taken from the head (top) and the other was taken from the butt (bottom) of the log. Two micros were mounted from each slice; one along the edge in the transverse direction and one from the center in the longitudinal direction with respect to the casting direction. Images of the as-polished pieces are shown in FIGS. 16A, 16B, 17, 18A, 18B, and 19.

[0118] After the as-polished micro images were taken, the micros were then etched electrolytically to further define the grain structure. Electrolytic etched images of the micros are shown in FIGS. 20-23.

EXAMPLE 6

[0119] METALLURGICAL RESULTS - EXTRUSION

[0120] Sample sections are taken from various charges of Example 2. Section

569510 display fine grain recrystallization while section 569310 exhibits a mixed grain structure of unrecrystallized and coarse grains.

[0121] The extruded grain structure for section 569310 is shown in FIGS. 24 and 25.

The grain structure for pieces extruded through section 569510 is shown in FIGS. 26 and 27.

[0122] Images containing electrolytically etched samples from both sections are located in FIGS. 28 and 29. The coarse grain recrystallization along the edges and weld is more evident for section 569310. The fine grain structure for section 569510 is also more visible. EXAMPLE 7

[0123] METALLURGICAL RESULTS - WELD INTEGRITY

[0124] The welds of each piece were inspected. Section 569510 showed signs of transverse welds in the front samples. The image of the transverse weld is shown in FIG. 30. The transverse welds were not present in the middle samples inspected, and it was determined that the front trim for the extruded length was not enough to vanquish the weld. The front trim was changed from twelve feet to fourteen feet to counteract it.

[0125] Section 569310 showed signs of bad welds in the center walls as shown in

FIG. 31. There is clear separation across the weld. The bad weld in the center wall was found in front, middle, and rear samples of charges four, five, and six, and in front and middle sections of charge seven. Since the bad weld was present in a significant amount of samples, it was determined that the design of the die was the most likely cause for the occurrence. Though the weld did not affect testing for this example, the die would need to be redesigned to prevent the bad weld from occurring.

EXAMPLE 7

[0126] GRAIN STRUCTURE AND DIE DESIGN

[0127] When extruding two similar sections with the same alloy, it is important to note the differences, if any, in the design of the dies that were used. The two sections (569310 and 569510) were run through the extruder at similar speeds and temperatures (as shown in Example 2 above) but had very different grain structures (as shown in Example 6 above).

[0128] The die design for section 569310 is shown in FIG. 32; the die design for section 569510 is shown in FIG. 33. There were a few dissimilarities between the dies. The die for section 569310 contains four ports for the aluminum to flow through as well as a six degree choke around the outside of the shape. In contrast, the die for section 569510 has five ports and no choke. Both choke and the number of ports have an effect on the recrystallization process.

[0129] The choke plays a big role in recrystallization of grains - specifically the lack of recrystallization. A choke helps to ease metal through the die which, in turn, causes less strain energy to be present. Grains will not recrystallize from the as-cast structure if there is not enough energy to do so. This lack of energy is what caused the unrecrystallized regions in section 569310 (FIG. 1) which had a six degree choke on the outside of the shape (FIG. 32). Section 569510 (FIG. 2) in comparison does not have any choke present (FIG. 33). The absence of choke (for example for section 569510) will increase the strain energy as the metal is pushed through, which could explain the recrystallization in the outer walls.

[0130] The number of ports present in the die design impacted the shapes a little differently. The extra fifth port on section 569510 is nearly twice the size of the other four, which caused metal to flow through it more freely and a little easier. The aluminum wanted to take this path because there is less resistance for it to flow. This increased the metal flow through the center which then increased the shear stresses in the metal. Increased shear stresses give the metal more energy that is necessary to recrystallize, so the entire center wall was able to recrystallize.

[0131] The compositions for the additives including at least chromium and manganese, as well as the extrusion practice, helped the alloy to recrystallize upon extruding through section 569510.

EXAMPLE 8

[0132] MECHANICAL PROPERTIES - EXTRUSION PROCESSING EFFECTS

[0133] The process run for the sections in Example 2 showed that billet and exit temperatures as well as extrusion speeds (Table 3 above) were acceptable and provided the appropriate amount of strength to the alloy. The billet temperatures were such to ensure that the material had the ability to extrude easily. The exit temperatures were set so that the Mg ₂ Si precipitates that were present dissolved. The speeds were as fast as the material could handle without tearing the material as well as make sure that the metal made it into quench so that the Mg ₂ Si could not precipitate out after it was dissolved.

[0134] The exit temperatures of each section of Example 2 during extrusion varied depending on the charge. The first charges of both sections had a lower exit temperature than the other five. This negatively impacts the strength of the metal. The lower exit temperatures cause the Mg ₂ Si precipitates to not dissolve completely which will cause them to become coarse and further apart from each other which allow more dislocations to move through the piece. FIG. 34 shows the yield strength as a function of exit temperature for the artificial age practice 338/347 °F for six hours for section 569310. Charges one and two experienced a lower strength than the rest of the group because of the lower exit temperature. Due to this drop in strength the first two charges were discarded from testing results.

EXAMPLE 9

[0135] COMPARISON

[0136] The artificial aging practice of 338/347°F for six hours described in Example

4 was determined to be the best choice compared with all of the other conditions described in Examples herein. The average yield strength for section 569310 and section 569510 at this time and temperature was between 330 and 335 MPa - above the minimum requirement of 320 MPa. The elongation for section 569310 had an average of 12% and the elongation for section 569510 was 10%. Though the elongation was not a requirement it is a benefit to the material. Using this age practice, HS6X has the ability to act as a suitable substitute to the 7003 aluminum alloy for automotive development. EXAMPLE 10

[0137] The following embodiments are meant to be illustrative and prophetic only.

Values are displayed in weight percents, with the balance aluminum unless otherwise stated.

[0138] In a first embodiment, one HS6X composition is as follows:

[0139] In a second embodiment, one HS6X composition is as follows:

[0142] While the present inventions have been illustrated and described in many embodiments of varying scope, it should be understood that such disclosures have been presented by way of example only and are not limiting - variations may be made within the spirit and scope of the inventions. Accordingly, it is intended that the scope of the inventions set forth in the appended claims not be limited by any specific wording in the foregoing description and above-described exemplary embodiments.