[001] 6xxx aluminum alloys are aluminum alloys having silicon and magnesium to produce the magnesium silicide (MgiSi) phase. The alloy 6061 has been used in various applications for several decades. However, improving one or more properties of an aluminum alloy without degrading other properties is elusive.

[002] 6xxx free-machining aluminum alloys, such as those containing tin, are described in commonly-owned U.S. Patent Nos. 5,522,950 and 7,422,645.

SUMMARY OF THE DISCLOSURE

[003] Broadly, the present patent application relates to new 6xxx aluminum alloys and methods for making the same. The new 6xxx aluminum alloys generally include from 0.5 to 1.5 wt. % Sn, from 0.4 to 1.6 wt. % Si, from 0.6 to 1.2 wt. % Mg, wherein a weight ratio of (wt. % Si) to (wt. % Mg) is at least 0.75: 1, from 0.5 to 1.1 wt. % Cu, from 0.15 to 1.5 wt. % Mn, from 0.10 to 0.80 wt. % Fe, wherein (wt. % Si) + (wt. % Mn) + (wt. % Fe) is at least 0.95 wt. %, up to 1.2 wt. % Bi, up to 1.2 wt. % In, up to 1.0 wt. % Zn, up to 0.35 wt. % Cr, up to 0.25 wt. % V, up to 0.25 wt. % Zr, up to 0.15 wt. % Ti, and up to 0.04 wt. % Pb, the balance being aluminum, optional incidental elements and impurities. In one embodiment, the new 6xxx aluminum alloy is in the form of an extruded product.

[004] Products made from the new 6xxx aluminum alloys may realize an improved combination of properties, such as an improved combination of two or more of strength, ductility (elongation), extrudability, extrusion temperature, extrusion speed, and the absence of visually apparent surface defects (e.g., devoid of cracking, hot tearing, and the like). The new aluminum alloys may be used in a variety of applications, such as for lead-free (Pb-free) machining applications.

[005] In one embodiment, a new 6xxx aluminum alloy product comprises a dispersoid area fraction (f) of at least 0.30%, wherein the dispersoids at least include FeMnsSiz dispersoids. A high volume fraction of dispersoids may, for instance, facilitate production of improved products having high strength, ductility, extrudability, lower extrusion temperatures, and/or higher extrusion speeds, among other things, without materially sacrificing machinability. i. Composition [006] As noted above, the new 6xxx aluminum alloys generally comprise (and in some instances consist essentially of, or consist of) from 0.5 to 1.5 wt. % Sn, from 0.4 to 1.6 wt. % Si, from 0.6 to 1.2 wt. % Mg, wherein a weight ratio of (wt. % Si) to (wt. % Mg) is at least 0.75: 1, from 0.5 to 1.1 wt. % Cu, from 0.15 to 1.5 wt. % Mn, from 0.10 to 0.80 wt. % Fe, wherein (wt. % Si) + (wt. % Mn) + (wt. % Fe) is at least 0.95 wt. %, up to 1.2 wt. % Bi, up to 1.2 wt. % In, up to 1.0 wt. % Zn, up to 0.35 wt. % Cr, up to 0.25 wt. % V, up to 0.25 wt. % Zr, up to 0.15 wt. % Ti, and up to 0.04 wt. % Pb, the balance being aluminum, optional incidental elements and impurities. [007] As noted above, a new 6xxx aluminum alloy generally includes from 0.5 to 1 .5 wt. % Sn. Tin may facilitate, among other things, machinability of the new 6xxx aluminum alloy products. In one embodiment, a new 6xxx aluminum alloy product includes at least 0.55 wt. % Sn. In another embodiment, a new 6xxx aluminum alloy product includes at least 0.60 wt. % Sn. In yet another embodiment, a new 6xxx aluminum alloy product includes at least 0.65 wt. % Sn. In another embodiment, a new 6xxx aluminum alloy product includes at least 0.70 wt. % Sn. In yet another embodiment, a new 6xxx aluminum alloy product includes at least 0.75 wt. % Sn. In another embodiment, a new 6xxx aluminum alloy product includes at least 0.80 wt. % Sn. In yet another embodiment, a new 6xxx aluminum alloy product includes at least 0.85 wt. % Sn. In another embodiment, a new 6xxx aluminum alloy product includes at least 0.90 wt. % Sn. In yet another embodiment, a new 6xxx aluminum alloy product includes at least 0.95 wt. % Sn. In another embodiment, a new 6xxx aluminum alloy product includes at least 1.0 wt. % Sn. In yet another embodiment, a new 6xxx aluminum alloy product includes at least 1.05 wt. % Sn. In another embodiment, a new 6xxx aluminum alloy product includes at least 1.10 wt. % Sn.

[008] In one embodiment, a new 6xxx aluminum alloy product includes not greater than 1.45 wt. % Sn. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 1.40 wt. % Sn. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 1.35 wt. % Sn. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 1.30 wt. % Sn.

[009] As noted above, a new 6xxx aluminum alloy generally includes from 0.4 to 1.6 wt. % Si. Silicon in combination with magnesium may facilitate, among other things, the presence of the Mg2Si phase. Elevated silicon levels may also facilitate production of higher volume fractions of FeMn ₃ Si ₂ dispersoids without materially affecting the volume fraction of Mg2Si phase present in the alloy. In one embodiment, a new 6xxx aluminum alloy product includes at least 0.45 wt. % Si. In another embodiment, a new 6xxx aluminum alloy product includes at least 0.50 wt. % Si. In yet another embodiment, a new 6xxx aluminum alloy product includes at least 0.55 wt. % Si. In another embodiment, a new 6xxx aluminum alloy product includes at least 0.60 wt. % Si. In yet another embodiment, a new 6xxx aluminum alloy product includes at least 0.65 wt. % Si. In another embodiment, a new 6xxx aluminum alloy product includes at least 0.70 wt. % Si. In yet another embodiment, a new 6xxx aluminum alloy product includes at least 0.75 wt. % Si. In another embodiment, a new 6xxx aluminum alloy product includes at least 0.80 wt. % Si.

[0010] In one embodiment, a new 6xxx aluminum alloy product includes not greater than 1 .55 wt. % Si. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 1.50 wt. % Si. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 1.45 wt. % Si. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 1.40 wt. % Si. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 1.35 wt. % Si. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 1.30 wt. % Si. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 1.25 wt. % Si. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 1.20 wt. % Si. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 1.15 wt. % Si. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 1.10 wt. % Si. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 1.05 wt. % Si. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 1.0 wt. % Si. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.95 wt. % Si. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.90 wt. % Si.

[0011] As noted above, a new 6xxx aluminum alloy generally includes from 0.6 to 1.2 wt. % Mg (e.g., to achieve an appropriate volume fraction of the Mg2Si phase and/or work hardening effects). In one embodiment, a new 6xxx aluminum alloy product includes at least 0.65 wt. % Mg. In another embodiment, a new 6xxx aluminum alloy product includes at least 0.70 wt. % Mg.

[0012] In one embodiment, a new 6xxx aluminum alloy product includes not greater than 1.15 wt. % Mg. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 1.10 wt. % Mg. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 1.05 wt. % Mg. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 1.0 wt. % Mg. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.95 wt. % Mg. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.90 wt. % Mg. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.85 wt. % Mg.

[0013] In one embodiment, a weight ratio of silicon-to-magnesium (Si:Mg) of the new 6xxx aluminum alloy product is at least 0.80: 1 ((wt. % Si) to (wt. % Mg)). In another embodiment, a weight ratio of silicon-to-magnesium (Si:Mg) of the new 6xxx aluminum alloy product is at least 0.85:1. In yet another embodiment, a weight ratio of silicon-to-magnesium (Si:Mg) of the new 6xxx aluminum alloy product is at least 0.90: 1. In another embodiment, a weight ratio of silicon- to-magnesium (Si:Mg) of the new 6xxx aluminum alloy product is at least 0.95: 1. In yet another embodiment, a weight ratio of silicon-to-magnesium (Si:Mg) of the new 6xxx aluminum alloy product is at least 1.0:1. In another embodiment, a weight ratio of silicon-to-magnesium (Si:Mg) of the new 6xxx aluminum alloy product is at least 1.05: 1. In yet another embodiment, a weight ratio of silicon-to-magnesium (Si:Mg) of the new 6xxx aluminum alloy product is at least 1.10: 1. In another embodiment, a weight ratio of silicon-to-magnesium (Si:Mg) of the new 6xxx aluminum alloy product is at least 1.15: 1.

[0014] In one embodiment, a weight ratio of silicon-to-magnesium (Si:Mg) of the new 6xxx aluminum alloy product is not greater than 2.2: 1. In another embodiment, a weight ratio of silicon- to-magnesium (Si:Mg) of the new 6xxx aluminum alloy product is not greater than 2.1 : 1. In yet another embodiment, a weight ratio of silicon-to-magnesium (Si:Mg) of the new 6xxx aluminum alloy product is not greater than 2.0:1. In another embodiment, a weight ratio of silicon-to- magnesium (Si:Mg) of the new 6xxx aluminum alloy product is not greater than 1.9:1. In another embodiment, a weight ratio of silicon-to-magnesium (Si:Mg) of the new 6xxx aluminum alloy product is not greater than 1.8:1. In yet another embodiment, a weight ratio of silicon-to- magnesium (Si:Mg) of the new 6xxx aluminum alloy product is not greater than 1.7: 1. In another embodiment, a weight ratio of silicon-to-magnesium (Si:Mg) of the new 6xxx aluminum alloy product is not greater than 1.6:1. In yet another embodiment, a weight ratio of silicon-to- magnesium (Si:Mg) of the new 6xxx aluminum alloy product is not greater than 1.5: 1. In another embodiment, a weight ratio of silicon-to-magnesium (Si:Mg) of the new 6xxx aluminum alloy product is not greater than 1.4:1. In yet another embodiment, a weight ratio of silicon-to- magnesium (Si:Mg) of the new 6xxx aluminum alloy product is not greater than 1.3: 1. In another embodiment, a weight ratio of silicon-to-magnesium (Si:Mg) of the new 6xxx aluminum alloy product is not greater than 1.2: 1.

[0015] In one embodiment, the total amount (in weight percent) of silicon and magnesium of a new 6xxx aluminum alloy product is at least 1.3 wt. % (i.e., (wt. % Si) plus (wt. % Mg) is > 1.3 wt. %). In another embodiment, the total amount of silicon and magnesium of a new 6xxx aluminum alloy product is at least 1.35 wt. %. In yet another embodiment, the total amount of silicon and magnesium of a new 6xxx aluminum alloy product is at least 1.40 wt. %. In another embodiment, the total amount of silicon and magnesium of a new 6xxx aluminum alloy product is at least 1.45 wt. %. In yet another embodiment, the total amount of silicon and magnesium of a new 6xxx aluminum alloy product is at least 1.50 wt. %. In another embodiment, the total amount of silicon and magnesium of a new 6xxx aluminum alloy product is at least 1.55 wt. %. In yet another embodiment, the total amount of silicon and magnesium of a new 6xxx aluminum alloy product is at least 1.60 wt. %. In another embodiment, the total amount of silicon and magnesium of a new 6xxx aluminum alloy product is at least 1.65 wt. %. In yet another embodiment, the total amount of silicon and magnesium of a new 6xxx aluminum alloy product is at least 1.70 wt. %.

[0016] In one embodiment, the total amount (in weight percent) of silicon and magnesium of a new 6xxx aluminum alloy product is not greater than 2.6 wt. % (i.e., (wt. % Si) plus (wt. % Mg) is < 2.6 wt. %). In another embodiment, the total amount of silicon and magnesium of a new 6xxx aluminum alloy product is not greater than 2.5 wt. %. In yet another embodiment, the total amount of silicon and magnesium of a new 6xxx aluminum alloy product is not greater than 2.4 wt. %. In another embodiment, the total amount of silicon and magnesium of a new 6xxx aluminum alloy product is not greater than 2.3 wt. %. In another embodiment, the total amount of silicon and magnesium of a new 6xxx aluminum alloy product is not greater than 2.2 wt. %. In yet another embodiment, the total amount of silicon and magnesium of a new 6xxx aluminum alloy product is not greater than 2.1 wt. %. In another embodiment, the total amount of silicon and magnesium of a new 6xxx aluminum alloy product is not greater than 2.0 wt. %. In yet another embodiment, the total amount of silicon and magnesium of a new 6xxx aluminum alloy product is not greater than 1.9 wt. %. In another embodiment, the total amount of silicon and magnesium of a new 6xxx aluminum alloy product is not greater than 1.85 wt. %. In yet another embodiment, the total amount of silicon and magnesium of a new 6xxx aluminum alloy product is not greater than 1.80 wt. %. In another embodiment, the total amount of silicon and magnesium of a new 6xxx aluminum alloy product is not greater than 1.75 wt. %.

[0017] As noted above, a new 6xxx aluminum alloy generally includes from 0.5 to 1.1 wt. % Cu. Copper may facilitate, for instance, production of strengthening phases, such as the Q phase. In one embodiment, a new 6xxx aluminum alloy product includes at least 0.55 wt. % Cu. In another embodiment, a new 6xxx aluminum alloy product includes at least 0.60 wt. % Cu. In yet another embodiment, a new 6xxx aluminum alloy product includes at least 0.65 wt. % Cu.

[0018] In one embodiment, a new 6xxx aluminum alloy product includes not greater than 1.05 wt. % Cu. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 1.0 wt. % Cu. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.95 wt. % Cu. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.90 wt. % Cu. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.85 wt. % Cu. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.80 wt. % Cu. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.75 wt. % Cu.

[0019] As noted above, a new 6xxx aluminum alloy generally includes from 0.15 to 1.5 wt. % Mn. Manganese may facilitate, for instance, production of a high volume fractions of FeMnsSi2 and other dispersoids. In one embodiment, a new 6xxx aluminum alloy product includes at least 0.18 wt. % Mn. In another embodiment, a new 6xxx aluminum alloy product includes at least 0.20 wt. % Mn. In yet another embodiment, a new 6xxx aluminum alloy product includes at least 0.22 wt. % Mn. In another embodiment, a new 6xxx aluminum alloy product includes at least 0.24 wt. % Mn. In yet another embodiment, a new 6xxx aluminum alloy product includes at least 0.26 wt. % Mn. In another embodiment, a new 6xxx aluminum alloy product includes at least 0.28 wt. % Mn. In yet another embodiment, a new 6xxx aluminum alloy product includes at least 0.30 wt. % Mn. In another embodiment, a new 6xxx aluminum alloy product includes at least 0.32 wt. % Mn. In yet another embodiment, a new 6xxx aluminum alloy product includes at least 0.34 wt. % Mn. In another embodiment, a new 6xxx aluminum alloy product includes at least 0.36 wt. % Mn. In yet another embodiment, a new 6xxx aluminum alloy product includes at least 0.38 wt. % Mn. In another embodiment, a new 6xxx aluminum alloy product includes at least 0.40 wt. % Mn.

[0020] In one embodiment, a new 6xxx aluminum alloy product includes not greater than 1.45 wt. % Mn. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 1.40 wt. % Mn. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 1.35 wt. % Mn. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 1.30 wt. % Mn. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 1.25 wt. % Mn. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 1.20 wt. % Mn. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 1.15 wt. % Mn. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 1.10 wt. % Mn. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 1.05 wt. % Mn. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 1.0 wt. % Mn. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.95 wt. % Mn. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.90 wt. % Mn. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.85 wt. % Mn. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.80 wt. % Mn. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.75 wt. % Mn. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.70 wt. % Mn. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.65 wt. % Mn. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.60 wt. % Mn. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.55 wt. % Mn. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.50 wt. % Mn. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.45 wt. % Mn. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.42 wt. % Mn.

[0021] As noted above, a new 6xxx aluminum alloy generally includes from 0.10 to 0.80 wt. % Fe. Iron may facilitate, for instance, production of a high volume fractions of FeMn3Si2 and other dispersoids. In one embodiment, a new 6xxx aluminum alloy product includes at least 0.15 wt. % Fe. In another embodiment, a new 6xxx aluminum alloy product includes at least 0.20 wt. % Fe. In yet another embodiment, a new 6xxx aluminum alloy product includes at least 0.25 wt. % Fe. In another embodiment, a new 6xxx aluminum alloy product includes at least 0.30 wt. % Fe. In yet another embodiment, a new 6xxx aluminum alloy product includes at least 0.35 wt. % Fe. In another embodiment, a new 6xxx aluminum alloy product includes at least 0.40 wt. % Fe. In yet another embodiment, a new 6xxx aluminum alloy product includes at least 0.45 wt. % Fe.

In another embodiment, a new 6xxx aluminum alloy product includes at least 0.50 wt. % Fe.

[0022] In one embodiment, a new 6xxx aluminum alloy product includes not greater than 0.75 wt. % Fe. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.70 wt. % Fe. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.65 wt. % Fe. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.60 wt. % Fe. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.55 wt. % Fe. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.52 wt. % Fe.

[0023] As noted above, a new 6xxx aluminum alloy generally includes a total amount (in weight percent) of silicon, manganese and iron of at least 0.95 wt. % (i.e., (wt. % Si) plus (wt. % Mn) plus (wt. % Fe) is > 0.95 wt. %). In one embodiment, the total amount of silicon, manganese and iron of a new 6xxx aluminum alloy product is at least 1.0 wt. %. In another embodiment, the total amount of silicon, manganese and iron of a new 6xxx aluminum alloy product is at least 1.05 wt. %. In yet another embodiment, the total amount of silicon, manganese and iron of a new 6xxx aluminum alloy product is at least 1.10 wt. %. In another embodiment, the total amount of silicon, manganese and iron of a new 6xxx aluminum alloy product is at least 1.15 wt. %. In yet another embodiment, the total amount of silicon, manganese and iron of a new 6xxx aluminum alloy product is at least 1.20 wt. %. In another embodiment, the total amount of silicon, manganese and iron of a new 6xxx aluminum alloy product is at least 1.25 wt. %. In yet another embodiment, the total amount of silicon, manganese and iron of a new 6xxx aluminum alloy product is at least 1.30 wt. %. In another embodiment, the total amount of silicon, manganese and iron of a new 6xxx aluminum alloy product is at least 1.35 wt. %. In yet another embodiment, the total amount of silicon, manganese and iron of a new 6xxx aluminum alloy product is at least 1.40 wt. %. In another embodiment, the total amount of silicon, manganese and iron of a new 6xxx aluminum alloy product is at least 1.45 wt. %. In yet another embodiment, the total amount of silicon, manganese and iron of a new 6xxx aluminum alloy product is at least 1.50 wt. %. In another embodiment, the total amount of silicon, manganese and iron of a new 6xxx aluminum alloy product is at least 1.55 wt. %. In yet another embodiment, the total amount of silicon, manganese and iron of a new 6xxx aluminum alloy product is at least 1.60 wt. %. [0024] In one embodiment, the total amount (in weight percent) of silicon, manganese, and iron of a new 6xxx aluminum alloy product is not greater than 3.1 wt. % (i.e., (wt. % Si) plus (wt. % Mn) plus (wt. % Fe) is < 3.1 wt. %). In another embodiment, the total amount of silicon, manganese and iron of a new 6xxx aluminum alloy product is not greater than 3.0 wt. %. In yet another embodiment, the total amount of silicon, manganese and iron of a new 6xxx aluminum alloy product is not greater than 2.9 wt. %. In another embodiment, the total amount of silicon, manganese and iron of a new 6xxx aluminum alloy product is not greater than 2.8 wt. %. In another embodiment, the total amount of silicon, manganese and iron of a new 6xxx aluminum alloy product is not greater than 2.7 wt. %. In yet another embodiment, the total amount of silicon, manganese and iron of a new 6xxx aluminum alloy product is not greater than 2.6 wt. %. In another embodiment, the total amount of silicon, manganese and iron of a new 6xxx aluminum alloy product is not greater than 2.5 wt. %. In another embodiment, the total amount of silicon, manganese and iron of a new 6xxx aluminum alloy product is not greater than 2.4 wt. %. In yet another embodiment, the total amount of silicon, manganese and iron of a new 6xxx aluminum alloy product is not greater than 2.3 wt. %. In another embodiment, the total amount of silicon, manganese and iron of a new 6xxx aluminum alloy product is not greater than 2.2 wt. %. In yet another embodiment, the total amount of silicon, manganese and iron of a new 6xxx aluminum alloy product is not greater than 2.1 wt. %. In another embodiment, the total amount of silicon, manganese and iron of a new 6xxx aluminum alloy product is not greater than 2.0 wt. %. In yet another embodiment, the total amount of silicon, manganese and iron of a new 6xxx aluminum alloy product is not greater than 1.9 wt. %. In another embodiment, the total amount of silicon, manganese and iron of a new 6xxx aluminum alloy product is not greater than 1.8 wt. %. In yet another embodiment, the total amount of silicon, manganese and iron of a new 6xxx aluminum alloy product is not greater than 1.7 wt. %.

[0025] As noted above, a new 6xxx aluminum alloy may include up to 1.2 wt. % Bi. Bismuth may be a substitute for tin, in whole or in part, in some alloying systems. However, bismuth phases are generally less preferred than tin phases. Thus, in some embodiments, a new 6xxx aluminum alloy product includes less than 0.25 wt. % Bi. In one embodiment, a new 6xxx aluminum alloy product includes not greater than 0.20 wt. % Bi. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.15 wt. % Bi. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.10 wt. % Bi. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.08 wt. % Bi. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.05 wt. % Bi. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.03 wt. % Bi. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.01 wt. % Bi. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.005 wt. % Bi.

[0026] In embodiments where bismuth is used, a new 6xxx aluminum alloy product generally includes from 0.25 to 1 .2 wt. % Bi.

[0027] As noted above, a new 6xxx aluminum alloy may include up to 1.2 wt. % In. Indium may be a substitute for tin, in whole or in part, in some alloying systems. However, indium phases are generally less preferred than tin phases. Thus, in some embodiments, a new 6xxx aluminum alloy product includes less than 0.25 wt. % In. In one embodiment, a new 6xxx aluminum alloy product includes not greater than 0.20 wt. % In. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.15 wt. % In. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.10 wt. % In. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.08 wt. % In. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.05 wt. % In. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.03 wt. % In. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.01 wt. % In. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.005 wt. % In.

[0028] In embodiments where indium is used, a new 6xxx aluminum alloy product generally includes from 0.25 to 1.2 wt. % In.

[0029] In one embodiment, a new 6xxx aluminum alloy product includes from 0.5 to 1.5 wt. % Sn, such as any of the tin levels listed herein, and the new 6xxx aluminum alloy product includes less than 0.05 wt. % Bi and less than 0.05 wt. % In. In another embodiment, a new 6xxx aluminum alloy product includes from 0.5 to 1.5 wt. % Sn, such as any of the tin levels listed herein, and the new 6xxx aluminum alloy product includes less than 0.03 wt. % Bi and less than 0.03 wt. % In. In yet another embodiment, a new 6xxx aluminum alloy product includes from 0.5 to 1.5 wt. % Sn, such as any of the tin levels listed herein, and the new 6xxx aluminum alloy product includes less than 0.01 wt. % Bi and less than 0.01 wt. % In. [0030] In one embodiment, a new 6xxx aluminum alloy product includes at least 0.25 wt. % each of at least two of tin, bismuth and indium. In another embodiment, a new 6xxx aluminum alloy product includes at least 0.25 wt. % each of all of tin, bismuth and indium.

[0031] As noted above, a new 6xxx aluminum alloy may include up to 1.0 wt. % Zn. Zinc may facilitate solid solution strengthening. In one embodiment, a new 6xxx aluminum alloy product includes at least 0.01 wt. % Zn. In one embodiment, a new 6xxx aluminum alloy product includes not greater than 0.9 wt. % Zn. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.8 wt. % Zn. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.7 wt. % Zn. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.6 wt. % Zn. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.50 wt. % Zn. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.40 wt. % Zn. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.30 wt. % Zn. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.20 wt. % Zn. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.15 wt. % Zn. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.10 wt. % Zn. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.08 wt. % Zn. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.05 wt. % Zn. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.03 wt. % Zn.

[0032] As noted above, a new 6xxx aluminum alloy may include up to 0.35 wt. % Cr. Chromium may facilitate, for instance, formation of chromium-containing dispersoids. In one embodiment, a new 6xxx aluminum alloy product includes at least 0.01 wt. % Cr. In another embodiment, a new 6xxx aluminum alloy product includes at least 0.03 wt. % Cr. In yet another embodiment, a new 6xxx aluminum alloy product includes at least 0.06 wt. % Cr. In another embodiment, a new 6xxx aluminum alloy product includes at least 0.08 wt. % Cr. In yet another embodiment, a new 6xxx aluminum alloy product includes at least 0.10 wt. % Cr. In another embodiment, a new 6xxx aluminum alloy product includes at least 0.12 wt. % Cr. In yet another embodiment, a new 6xxx aluminum alloy product includes at least 0.14 wt. % Cr. In another embodiment, a new 6xxx aluminum alloy product includes at least 0.16 wt. % Cr. In yet another embodiment, a new 6xxx aluminum alloy product includes at least 0.18 wt. % Cr. [0033] In one embodiment, a new 6xxx aluminum alloy product includes not greater than 0.30 wt. % Cr. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.25 wt. % Cr. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.22 wt. % Cr. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.20 wt. % Cr.

[0034] As noted above, a new 6xxx aluminum alloy may include up to 0.25 wt. % V. Vanadium may be a substitute in whole or in part for chromium. In one embodiment, a new 6xxx aluminum alloy product includes at least 0.01 wt. % V. In one embodiment, a new 6xxx aluminum alloy product includes not greater than 0.15 wt. % V. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.10 wt. % V. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.08 wt. % V. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.05 wt. % V. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.03 wt. % V. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.01 wt. % V. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.005 wt. % V.

[0035] As noted above, a new 6xxx aluminum alloy may include up to 0.25 wt. % Zr. Zirconium may be a substitute in whole or in part for chromium. In one embodiment, a new 6xxx aluminum alloy product includes at least 0.01 wt. % Zr. In one embodiment, a new 6xxx aluminum alloy product includes not greater than 0.15 wt. % Zr. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.10 wt. % Zr. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.08 wt. % Zr. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.05 wt. % Zr. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.03 wt. % Zr. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.01 wt. % Zr. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.005 wt. % Zr.

[0036] In one embodiment, at least one of zirconium and vanadium is partially substituted for chromium.

[0037] As noted above, a new 6xxx aluminum alloy generally includes not greater than 0.15 wt. % Ti. Titanium may be used during casting for grain refinement. The amount of titanium in the alloy should be restricted such that large primary particles are avoided / restricted / limited during production of alloy products. In one embodiment, a new 6xxx aluminum alloy product includes at least 0.005 wt. % Ti. In another embodiment, a new 6xxx aluminum alloy product includes at least 0.01 wt. % Ti. In yet another embodiment, a new 6xxx aluminum alloy product includes at least 0.02 wt. % Ti. In yet another embodiment, a new 6xxx aluminum alloy product includes at least 0.05 wt. % Ti. In one embodiment, a new 6xxx aluminum alloy product includes not greater than 0.12 wt. % Ti. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.10 wt. % Ti. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.08 wt. % Ti. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.05 wt. % Ti. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.03 wt. % Ti. In one embodiment, a new 6xxx aluminum alloy product includes from 0.005 to 0.10 wt. % Ti. In another embodiment, a new 6xxx aluminum alloy product includes from 0.01 to 0.05 wt. % Ti. In yet another embodiment, a new 6xxx aluminum alloy product includes from 0.01 to 0.03 wt. % Ti. The titanium may be in elemental form or in the form of compounds (e.g., TiEh or TiC).

[0038] As noted above, a new 6xxx aluminum alloy generally include not greater than 0.04 wt. % Pb. Lead may be considered hazardous in some countries. In one embodiment, a new 6xxx aluminum alloy includes not greater than 0.03 wt. % Pb. In another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.01 wt. % Pb. In yet another embodiment, a new 6xxx aluminum alloy product includes not greater than 0.005 wt. % Pb.

[0039] As noted above, the balance of the aluminum alloys is generally aluminum, optional incidental elements and impurities. As used herein, “incidental elements” means those elements or materials, other than the above listed elements, that may optionally be added to the alloy to assist in the production of the alloy. Examples of incidental elements include casting aids, such as grain refiners and deoxidizers. Optional incidental elements may be included in the alloy in a cumulative amount of up to 1.0 wt. %. As one non-limiting example, one or more incidental elements may be added to the alloy during casting to reduce or restrict (and is some instances eliminate) ingot cracking due to, for example, oxide fold, pit and oxide patches. These types of incidental elements are generally referred to herein as deoxidizers. Examples of some deoxidizers include Ca, Sr, and Be. When calcium (Ca) is included in the alloy, it is generally present in an amount of up to about 0.05 wt. %, or up to about 0.03 wt. %. In some embodiments, Ca is included 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 to 80 ppm). Strontium (Sr) may be included in the alloy as a substitute for Ca (in whole or in part), and thus may be included in the alloy in the same or similar amounts as Ca. Traditionally, beryllium (Be) additions have helped to reduce the tendency of ingot cracking, though for environmental, health and safety reasons, some embodiments of the alloy are substantially Be-free. When Be is included in the alloy, it is generally present in an amount of up to about 20 ppm. Incidental elements may be present in minor amounts, or may be present in significant amounts, and may add desirable or other characteristics on their own without departing from the alloy described herein, so long as the alloy retains the desirable characteristics described herein. It is to be understood, however, that the scope of this disclosure should not/cannot be avoided through the mere addition of an element or elements in quantities that would not otherwise impact on the combinations of properties desired and attained herein.

[0040] The new 6xxx aluminum alloys may contain low amounts of impurities. In one embodiment, a new 6xxx aluminum alloy product includes not greater than 0.15 wt. %, in total, of the impurities, and wherein the new aluminum alloy includes not greater than 0.05 wt. % of each of the impurities. In another embodiment, a new 6xxx aluminum alloy products includes not greater than 0.10 wt. %, in total, of the impurities, and wherein the new aluminum alloy includes not greater than 0.03 wt. % of each of the impurities.

77. Processing

[0041] The new aluminum alloys may be useful in a variety of product forms, including ingot or billet, wrought product forms (plate, forgings and extrusions), shape castings, additively manufactured products, and powder metallurgy products, for instance. For example, the new aluminum alloys may be processed into a variety of wrought forms, such as in rolled form (sheet, plate), as an extrusion, or as a forging, and in a variety of tempers. In this regard, the new aluminum alloys may be cast (e.g., direct chill cast or continuously cast), and then worked (hot and/or cold worked) into the appropriate product form (sheet, plate, extrusion, or forging). After working, the new aluminum alloys may be processed to one of a T temper, a W temper, O temper, or an F temper as per ANSI H35.1 (2009). In one embodiment, a new aluminum alloy is processed to a “T temper” (thermally treated). In this regard, the new aluminum alloys may be processed to any of a Tl, T2, T3, T4, T5, T6, T7, T8, T9 or T10 temper as per ANSI H35.1 (2009). In one embodiment, the product is processed to a Tl temper. In another embodiment, the product is processed to a T2 temper. In yet another embodiment, the product is processed to a T3 temper. In another embodiment, the product is processed to a T4 temper. In another embodiment, the product is processed to a T5 temper. In yet another embodiment, the product is processed to a T6 temper. In another embodiment, the product is processed to a T7 temper. In yet another embodiment, the product is processed to a T8 temper. In another embodiment, the product is processed to a T9 temper. In yet another embodiment, the product is processed to a T10 temper. In other embodiments, a new aluminum alloy is processed to an “W temper” (solution heat treated). In another embodiment, no solution heat treatment is applied after working the aluminum alloy into the appropriate product form, and thus the new aluminum alloys may be processed to an “F temper” (as fabricated) or “O temper” (annealed).

[0042] In one embodiment, a new 6xxx aluminum alloy product is an extruded product. In one embodiment, the extruded product is processed to a Tl, T2, T3, T4, T5, T6, T7, T8, T9 or T10 temper. For instance, an extruded product may be produced by casting a billet of any of the 6xxx aluminum alloys described herein, followed by scalping/peeling and homogenization (in any order), followed by extruding (directly or indirectly) at an extrusion temperature. Any suitable extrusion technique can be utilized including hydrostatic extrusion. The extruded products may be of any suitable form, such as a rod, bar, shape or any other geometric shape/profile. The extruded product may be an intermediate product or a final product. Immediately after extrusion, the product may be purposefully quenched to produce a press-quenched and then naturally aged, i.e., a Tl temper, and/or then artificially aged, i.e., a T5 temper product. Alternatively, the extruded product may be solution heat treated (e.g., in a separate furnace), quenched and then naturally aged, i.e., a T4 temper product, and/or then artificially aged, i.e., a T6 temper product. In another embodiment, an extruded product is further cold worked and/or artificially aged after extruding. For the T8 temper, cold working is first completed followed by artificial aging. For the T9 temper, artificial aging is first completed followed by cold working.

[0043] Unlike the extrusion conditions described by commonly-owned U.S. Patent No. 7,422,645, billets made from the new 6xxx aluminum alloy products described herein may be homogenized at any suitable homogenization temperature (e.g., from 1010°F to 1040°F), and then either (a) immediately extruded or (b) air or water quenched and later extruded. In either case, the pre-heat temperature (i.e., the temperature at which the billet enters the extrusion press) may be significantly higher than the 800°F preferred maximum described by U.S. Patent No. 7,422,645. In one aspect, the pre-heat temperature is greater than 800°F. In one approach, the pre-heat temperature is in the range of from 810°F to 960°F. In one embodiment, the pre-heat temperature is at least 820°F. In another embodiment, the pre-heat temperature is at least 830°F. In yet another embodiment, the pre-heat temperature is at least 840°F. In another embodiment, the pre-heat temperature is at least 850°F. In yet another embodiment, the pre-heat temperature is at least 860°F. In another embodiment, the pre-heat temperature is at least 870°F. In yet another embodiment, the pre-heat temperature is at least 880°F. In another embodiment, the pre-heat temperature is at least 890°F. In yet another embodiment, the pre-heat temperature is at least 900°F. In another embodiment, the pre-heat temperature is at least 905°F. In yet another embodiment, the pre-heat temperature is at least 910°F. In another embodiment, the pre-heat temperature is at least 915°F. In yet another embodiment, the pre-heat temperature is at least 920°F. In one embodiment, the pre-heat temperature is not greater than 950°F.

[0044] In one embodiment, the pre-heat temperature is from 900°F to 960°F. In another embodiment, the pre-heat temperature is from 905-960°F. In yet another embodiment, the preheat temperature is from 910-960°F. In another embodiment, the pre-heat temperature is from 915-960°F. In yet another embodiment, the pre-heat temperature is from 920-960°F.

[0045] In one embodiment, the extrusion speed is from 40 to 70 feet per minute.

[0046] As noted above, the new 6xxx aluminum alloys described herein may facilitate extruding colder and/or extruding faster without concomitant material loss of mechanical properties and/or without occurrence of visually apparent surface defects (e.g., without cracking, hot tearing, and the like). Thus, higher throughputs may be realized without materially sacrificing quality.

[0047] In one embodiment, the extrusion process is initiated at the pre-heat temperature and a method of extrusion includes extruding the billet into an extruded product. In one embodiment, a method comprises quenching the extrusion during the extruding step (e.g., immediately as the extrusion exits the extrusion apparatus). In another embodiment, a method comprises, after the extruding step, solution heat treating in a separate furnace and then quenching the extruded product. In one embodiment, a method comprises artificially aging the extruded product. In one embodiment, a method comprises cold working the extruded product and then artificially aging the extruded product. In one embodiment, a method comprises artificially aging the extruded product and then cold working the extruded product. Natural aging may be used in lieu of or prior to artificial aging.

Hi. Microstructure

[0048] As noted above, the new 6xxx aluminum alloy products may realize a unique microstructure, such as a high volume fraction of dispersoids and/or a high volume fraction of <111> microtextures, defined below. The volume fraction of dispersoids and/or the volume fraction of <1 11> microtextures are to be determined in accordance with the Microstructure Assessment Procedure, described below.

[0049] In one embodiment, and as noted above, a new 6xxx aluminum alloy product comprises a dispersoid area fraction (f) of at least 0.30%, wherein the dispersoids comprise feMnsSir dispersoids. In another embodiment, a new 6xxx aluminum alloy product comprises a dispersoid area fraction (f) of at least 0.35%. In yet another embodiment, a new 6xxx aluminum alloy product comprises a dispersoid area fraction (f) of at least 0.40%. In another embodiment, a new 6xxx aluminum alloy product comprises a dispersoid area fraction (f) of at least 0.45%. In yet another embodiment, a new 6xxx aluminum alloy product comprises a dispersoid area fraction (f) of at least 0.50%. In another embodiment, a new 6xxx aluminum alloy product comprises a dispersoid area fraction (f) of at least 0.55%. In yet another embodiment, a new 6xxx aluminum alloy product comprises a dispersoid area fraction (f) of at least 0.60%. In another embodiment, a new 6xxx aluminum alloy product comprises a dispersoid area fraction (f) of at least 0.65%. In yet another embodiment, a new 6xxx aluminum alloy product comprises a dispersoid area fraction (f) of at least 0.70%. In another embodiment, a new 6xxx aluminum alloy product comprises a dispersoid area fraction (f) of at least 0.75%. In yet another embodiment, a new 6xxx aluminum alloy product comprises a dispersoid area fraction (f) of at least 0.80%. In another embodiment, a new 6xxx aluminum alloy product comprises a dispersoid area fraction (f) of at least 0.85%. In yet another embodiment, a new 6xxx aluminum alloy product comprises a dispersoid area fraction (f) of at least 0.90%. In another embodiment, a new 6xxx aluminum alloy product comprises a dispersoid area fraction (f) of at least 0.95%. In yet another embodiment, a new 6xxx aluminum alloy product comprises a dispersoid area fraction (f) of at least 1.0%. In another embodiment, a new 6xxx aluminum alloy product comprises a dispersoid area fraction (f) of at least 1.05%. In yet another embodiment, a new 6xxx aluminum alloy product comprises a dispersoid area fraction (f) of at least 1.10%. [0050] In one embodiment, a new 6xxx aluminum alloy product realizes a mean (average) dispersoid size of from 0.05 to 0.20 micrometers.

[0051] In one embodiment, a D90 of the dispersoids is not greater than 0.30 micrometers. In another embodiment, a D90 of the dispersoids is not greater than 0.27 micrometers. In yet another embodiment, a D90 of the dispersoids is not greater than 0.24 micrometers. In another embodiment, a D90 of the dispersoids is not greater than 0.21 micrometers. In yet another embodiment, a D90 of the dispersoids is not greater than 0.19 micrometers. In another embodiment, a D90 of the dispersoids is not greater than 0.18 micrometers.

[0052] In one embodiment, a D10 of the dispersoids is at least 0.02 micrometers. In another embodiment, a D10 of the dispersoids is at least 0.03 micrometers. In yet another embodiment, a D10 of the dispersoids is at least 0.04 micrometers.

[0053] In one embodiment, a new 6xxx aluminum alloy product comprises at least 3 vol. % <111> microtexture. In another embodiment, a new 6xxx aluminum alloy product comprises at least 5 vol. % <111> microtexture. In yet another embodiment, a new 6xxx aluminum alloy product comprises at least 7 vol. % <111> microtexture. In another embodiment, a new 6xxx aluminum alloy product comprises at least 9 vol. % <111> microtexture. In yet another embodiment, a new 6xxx aluminum alloy product comprises at least 11 vol. % <111> microtexture. In another embodiment, a new 6xxx aluminum alloy product comprises at least 13 vol. % <111> microtexture. In yet another embodiment, a new 6xxx aluminum alloy product comprises at least 15 vol. % <111> microtexture. In another embodiment, a new 6xxx aluminum alloy product comprises at least 17 vol. % <111> microtexture. In yet another embodiment, a new 6xxx aluminum alloy product comprises at least 19 vol. % <111> microtexture. In another embodiment, a new 6xxx aluminum alloy product comprises at least 21 vol. % <111> microtexture. In yet another embodiment, a new 6xxx aluminum alloy product comprises at least 23 vol. % <111> microtexture. In another embodiment, a new 6xxx aluminum alloy product comprises at least 25 vol. % <111> microtexture. In yet another embodiment, a new 6xxx aluminum alloy product comprises at least 27 vol. % <111> microtexture. In another embodiment, a new 6xxx aluminum alloy product comprises at least 29 vol. % <111> microtexture. In yet another embodiment, a new 6xxx aluminum alloy product comprises at least 31 vol. % <111> microtexture. In another embodiment, a new 6xxx aluminum alloy product comprises at least 33 vol. % <111> microtexture. In yet another embodiment, a new 6xxx aluminum alloy product comprises at least 35 vol. % <111> microtexture. In another embodiment, a new 6xxx aluminum alloy product comprises at least 37 vol. % <111> microtexture. In yet another embodiment, a new 6xxx aluminum alloy product comprises at least 39 vol. % <111> microtexture. iv. Properties

[0054] As noted above, the new aluminum alloys may realize an improved combination of properties. For instance, products made from the new 6xxx aluminum alloys may realize an improved combination of two or more of strength, ductility (elongation), extrudability, extrusion temperature, extrusion speed, and the absence of visually apparent surface defects (e.g., devoid of cracking, hot tearing, and the like).

[0055] In one embodiment, a new 6xxx aluminum alloy product realizes a tensile yield strength (LT) of at least 40 ksi. In another embodiment, a new 6xxx aluminum alloy product realizes a tensile yield strength (LT) of at least 41 ksi. In yet another embodiment, a new 6xxx aluminum alloy product realizes a tensile yield strength (LT) of at least 42 ksi. In another embodiment, a new 6xxx aluminum alloy product realizes a tensile yield strength (LT) of at least 43 ksi. In yet another embodiment, a new 6xxx aluminum alloy product realizes a tensile yield strength (LT) of at least 44 ksi. In another embodiment, a new 6xxx aluminum alloy product realizes a tensile yield strength (LT) of at least 45 ksi. In yet another embodiment, a new 6xxx aluminum alloy product realizes a tensile yield strength (LT) of at least 46 ksi. In another embodiment, a new 6xxx aluminum alloy product realizes a tensile yield strength (LT) of at least 47 ksi. In yet another embodiment, a new 6xxx aluminum alloy product realizes a tensile yield strength (LT) of at least 48 ksi. In another embodiment, a new 6xxx aluminum alloy product realizes a tensile yield strength (LT) of at least 49 ksi. In yet another embodiment, a new 6xxx aluminum alloy product realizes a tensile yield strength (LT) of at least 50 ksi. In another embodiment, a new 6xxx aluminum alloy product realizes a tensile yield strength (LT) of at least 51 ksi. In yet another embodiment, a new 6xxx aluminum alloy product realizes a tensile yield strength (LT) of at least 52 ksi. In another embodiment, a new 6xxx aluminum alloy product realizes a tensile yield strength (LT) of at least 53 ksi. In yet another embodiment, a new 6xxx aluminum alloy product realizes a tensile yield strength (LT) of at least 54 ksi. The properties identified in this paragraph may be realized in a variety of tempers, including the T5 and T8 tempers. [0056] In one embodiment, a new 6xxx aluminum alloy product realizes an ultimate tensile strength (LT) of at least 43 ksi. In another embodiment, a new 6xxx aluminum alloy product realizes an ultimate tensile strength (LT) of at least 44 ksi. In another embodiment, a new 6xxx aluminum alloy product realizes an ultimate tensile strength (LT) of at least 45 ksi. In yet another embodiment, a new 6xxx aluminum alloy product realizes an ultimate tensile strength (LT) of at least 46 ksi. In another embodiment, a new 6xxx aluminum alloy product realizes an ultimate tensile strength (LT) of at least 47 ksi. In yet another embodiment, a new 6xxx aluminum alloy product realizes an ultimate tensile strength (LT) of at least 48 ksi. In another embodiment, a new 6xxx aluminum alloy product realizes an ultimate tensile strength (LT) of at least 49 ksi. In yet another embodiment, a new 6xxx aluminum alloy product realizes an ultimate tensile strength (LT) of at least 50 ksi. In another embodiment, a new 6xxx aluminum alloy product realizes an ultimate tensile strength (LT) of at least 51 ksi. In yet another embodiment, a new 6xxx aluminum alloy product realizes an ultimate tensile strength (LT) of at least 52 ksi. In another embodiment, a new 6xxx aluminum alloy product realizes an ultimate tensile strength (LT) of at least 53 ksi. In yet another embodiment, a new 6xxx aluminum alloy product realizes an ultimate tensile strength (LT) of at least 54 ksi. In another embodiment, a new 6xxx aluminum alloy product realizes an ultimate tensile strength (LT) of at least 55 ksi. In yet another embodiment, a new 6xxx aluminum alloy product realizes an ultimate tensile strength (LT) of at least 56 ksi. The properties identified in this paragraph may be realized in a variety of tempers, including the T5 and T8 tempers.

[0057] In one embodiment, a new 6xxx aluminum alloy product realizes an elongation (LT) of at least 8%. In another embodiment, a new 6xxx aluminum alloy product realizes an elongation (LT) of at least 9%. In yet another embodiment, a new 6xxx aluminum alloy product realizes an elongation (LT) of at least 10%. In another embodiment, a new 6xxx aluminum alloy product realizes an elongation (LT) of at least 11%. In yet another embodiment, a new 6xxx aluminum alloy product realizes an elongation (LT) of at least 12%. In another embodiment, a new 6xxx aluminum alloy product realizes an elongation (LT) of at least 13%. In yet another embodiment, a new 6xxx aluminum alloy product realizes an elongation (LT) of at least 14%. The properties identified in this paragraph may be realized in a variety of tempers, including the T5 and T8 tempers. v. Product Applications [0058] The new 6xxx aluminum alloys described herein may be used in a variety of applications, such as in applications where free machining is required, i.e., the new 6xxx aluminum alloy may be used as a free machining alloy. In one embodiment, a new 6xxx aluminum alloy is in the form of an extruded rod. vi. Definitions

[0059] “Wrought aluminum alloy product” means an aluminum alloy product that is hot worked after casting, and includes rolled products (sheet or plate), forged products, and extruded products.

[0060] “Hot working” such as by hot rolling means working the aluminum alloy product at elevated temperature, and generally at least 121.1°C (250°F). Strain-hardening is restricted / avoided during hot working, which generally differentiates hot working from cold working.

[0061] “Cold working” such as by cold rolling means working the aluminum alloy product at temperatures that are not considered hot working temperatures, generally below about 121. 1°C (250°F) (e.g., at ambient).

[0062] Temper definitions are per ANSI H35.1 (2009), entitled “American National Standard Alloy and Temper Designation Systems for Aluminum,” published by The Aluminum Association.

[0063] Strength and elongation are measured in accordance with ASTM E8/E8M-16a and B557-15. vii. Microstructure Assessment Procedure

[0064] The following procedures and definitions apply to measuring microstructure features (e g., dispersoid content and size, volume fraction of <111> microtexture) for products made in accordance with present patent application.

A. Dispersoids

[0065] “Dispersoid area fraction”, f, is the area fraction covered by dispersoid particles divided by the total area examined in a two-dimensional cross section prepared by standard metallographic sample preparation methods.

[0066] “Dispersoid area %” is determined via the formula f x 100. [0067] “Dispersoid average diameter” is the average of all measured dispersoid diameters, di, where each diameter is an equivalent diameter calculated assuming each dispersoid area measured on a two-dimensional cross section is a circle of the effective diameter: d, = square root (— )

[0068] To measure the dispersoid area fraction, f, and dispersoid average diameters, backscattered electron images should be taken at different magnifications and contrast/brightness settings to determine the lowest magnification that will adequately capture the smallest size dispersoids. Brightness/contrast settings are determined to be acceptable when the dispersoids are significantly brighter than the background matrix and the edges of the particles are easily identifiable. Typically, the on-screen magnification will be from lOOOx-lOOOOx. For the images of Example 1, below, the on-screen magnification was 5000x. An Apreo S Field Emission Gun (Thermo Fisher Scientific, Waltham, MA, U.S.A) scanning electron microscope, or equivalent, is used to image dispersoids. The images should be taken using an accelerating voltage 5kV. Beam current should be 0.8 nanoamps. Working distance should be 5 mm. Dwell time should be 5 microseconds. Line averaging should be 3. At least twenty images are to be collected from metallographically polished specimens for each alloy at, or in close proximity to, T/2 or D/2, as applicable. For each sample, images should be captured from several different, random locations, such that the total analysis is representative of the microstructure. Images with any scratches, foreign features, or focus issues should be eliminated, though twenty acceptable images is still the minimum to be analyzed. MIPAR version 3.3.4 or equivalent should be used for the image analysis to quantify the images. The pixel size for quantifying dispersoids will vary based on magnification and image resolution. A pixel size of 0.008 micrometers was used for the image analysis done for Example 1. The peak (mode) of the image histograms, corresponding to the average background levels, were 69-71 for an 8-bit image that extends from 0 (black) to 255 (white). Pixels are only counted as belong to dispersoids if their gray scale value is 40% greater than background, i.e., a global threshold of 100. Particles are not counted as being dispersoids if their area consists of less than 20 contiguous pixels, if the particle is above 1500 pixels, or if the mean intensity of all pixels in the particle is not 10% greater than the minimum threshold value defined above. Prior to analysis, each image frame is reviewed and any non-dispersoids particles are manually erased; non-dispersoid particles may include debris on the surface, such as polishing compound, or image artifacts, such as charging A data file (e.g.. EXCEL, Microsoft, U.S.A.) is generated which displays statistics for each particle. Calculations are made based on the data file. The equivalent diameter is generated for each particle by taking the total particle area and calculating the diameter if that particle were to be a perfect circle.

[0069] FIG. IB illustrates an example image for particle size analysis. FIG. 1A is a SEM processed in accordance with the above procedure to produce FIG. IB.

[0070] B. Volume Fraction of<lll> Microtexture

[0071] “Percent <l l l>-microtexture” and the like means the volume percent (fraction) of <111> crystallographic direction of a wrought aluminum alloy product that are closely aligned with the L direction (e.g., the extrusion direction for an extruded product). The amount of <111> microtexture is determined by EBSD (electron backscatter diffraction) analysis of a suitable area of the wrought aluminum alloy product. A high amount of <111> microtexture is indicative of a unrecrystallized microstructure whereas a low amount of <111> microtexture is indicative of a recrystallized microstructure.

[0072] The EBSD analysis is to be completed across the full width of the wrought product sample on the LT-ST plane, using the EBSD sample procedure, below. The size of the sample to be analyzed will generally vary by wrought product size and shape, e.g., the extrusion profile size and shape. Prior to measurement, the EBSD samples are prepared by standard metallographic sample preparation methods. For example, the EBSD samples are metallographically prepared and then polished (e.g., using 0.05 micron colloidal silica). The samples are then anodized in Barker’s reagent, a diluted fluoroboric acid solution, for 90 seconds. The samples are then stripped using an aqueous phosphoric acid solution containing chromium trioxide, and then rinsed and dried.

[0073] The “EBSD sample procedure” is as follows:

• The software used is APEX EBSD Collection Software, Version 2 (EDAX Inc., New Jersey, U.S.A ), or equivalent, which is connected to a Velocity EBSD camera (EDAX Inc., New Jersey, U.S.A.), or equivalent. The SEM is an APREO S Field Emission Gun (Thermo Fisher Scientific. Waltham, MA, U.S.A.), or equivalent.

• EBSD run conditions are 68° tilt with a 18 mm working distance and an accelerating voltage of 20 kV with dynamic focusing and an instrument-specified beam current of 26 nA (nanoamps). The mode of collection is square grid. A selection is made such that orientations are collected in the analysis (i.e., Hough peaks information is not collected). The scans are collected at 3 micron steps at 120X over multiple frames to cover the entire sample width. The APEX software mergers the frames together. If it is not possible to scan the entire sample, e.g. the profile dimensions are too large, then several discrete locations can be mapped, provided that, when analyzed en mass, the results represent the average for the compete extrudate. The collected data is output in an *.osc file. This data may be used to calculate the volume fraction of <111> microtexture, as described below.

• Calculation of volume fraction of <111> microtexture: The volume fraction of <111> microtexture is calculated using the data of the *.osc file and the OIM Analysis Software (ED AX Inc., New Jersey, U.S.A.), version 8.5.1, or equivalent. Prior to calculation, two-step data cleanup may be performed. First, for any points whose confidence index is below a threshold of 0.10, a neighbor orientation correlation clean-up is performed needing 5 similarly oriented neighbors [out of the possible 8], Second, a grain dilation clean-up is performed for any grain smaller than 3 data points, whose confidence index is below a threshold of 0.15. Then, the amount of <111> microtexture is calculated by the software using the <111> microtexture criteria (below).

• <111> microtexture criteria: Crystal direction maps are generated for <111> aligned within 10° of the longitudinal axis (e.g., the extrusion axis), which corresponds to the normal direction for the EBSD scan of the LT-ST plane. The software calculates the area fraction for all points contained within this partition. Since the crystallographic texture measurements are three-dimensional, the calculated area fractions are equivalent to volume fractions (volume percents). viii. Miscellaneous

[0074] These and other aspects, advantages, and novel features of this new technology are set forth in part in the description that follows and will become apparent to those skilled in the art upon examination of the following description and figures, or may be learned by practicing one or more embodiments of the technology provided for by the present disclosure. [0075] Among those benefits and improvements that have been disclosed, other objects and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying figures. Detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely illustrative of the invention that may be embodied in various forms. In addition, each of the examples given in connection with the various embodiments of the invention is intended to be illustrative, and not restrictive.

[0076] Throughout the specification and claims, the following terms take the meanings explicitly associated herein, unless the context clearly dictates otherwise. The phrases “in one embodiment” and “in some embodiments” as used herein do not necessarily refer to the same embodiment(s), though they may. Furthermore, the phrases “in another embodiment” and “in some other embodiments” as used herein do not necessarily refer to a different embodiment, although they may. Thus, various embodiments of the invention may be readily combined, without departing from the scope or spirit of the invention.

[0077] In addition, as used herein, the term “or” is an inclusive “or” operator, and is equivalent to the term “and/or,” unless the context clearly dictates otherwise. The term “based on” is not exclusive and allows for being based on additional factors not described, unless the context clearly dictates otherwise. In addition, throughout the specification, the meaning of “a,” “an,” and “the” include plural references, unless the context clearly dictates otherwise. The meaning of “in” includes “in” and “on”, unless the context clearly dictates otherwise.

[0078] While a number of embodiments of the present invention have been described, it is understood that these embodiments are illustrative only, and not restrictive, and that many modifications may become apparent to those of ordinary skill in the art. Further still, unless the context clearly requires otherwise, the various steps may be carried out in any desired order, and any applicable steps may be added and/or eliminated.

BRIEF DESCRIPTION OF THE DRAWINGS

[0079] FIG. 1A is an SEM image of a representative one of Alloys 4-6 of Example 1.

[0080] FIG. IB is a processed version of the SEM image of FIG. 1A used for particle

(dispersoid) size analysis.

[0081] FIG. 2 is a graph showing dispersoid particle size distributions of the Example 1 alloys. [0082] FIG. 3A is a representative microstructure of a standard 6020 alloy from Example 1 taken across the entire width of the extruded rod and centered at D/2; the microstructure is a <111> crystal direction map generated by EBSD data for points aligned within 10° of the extrusion axis. [0083] FIG. 3B is a representative microstructure of Alloys 1-3 from Example 1 taken across the entire width of the extruded rod and centered at D/2; the microstructure is a <111> crystal direction map generated by EBSD data for points aligned within 10° of the extrusion axis.

[0084] FIG. 3C is a representative microstructure of Alloys 4-6 from Example 1 taken across the entire width of the extruded rod and centered at D/2; the microstructure is a <111> crystal direction map generated by EBSD data for points aligned within 10° of the extrusion axis.

DETAILED DESCRIPTION

[0085] Example 1

[0086] Six industrial-scale billets (11-inch (D) x 40-inch (L); 27.9 cm (D) x 101.6 cm (L)) of the new aluminum alloys shown in Table 1 were cast. Three conventional 6020 billets of the same size were also cast, the average composition of which is provided in Table 1, below.

Table 1 - Composition of Ex, 1 Alloys (in wt. %)

* The balance of the alloy was incidental elements and impurities, where the alloy contained not greater than 0.03 wt. % of any one impurity, and where the alloy contained not greater than 0.10 wt. %, in total, of all impurities.

[0087] After casting, the billets were homogenized, and then extruded to coiled rods of 0.637 inch (16.17 mm) diameter at a nominal temperature of 940 °F (504 °C) (furnace set-point) and at an extrusion speed of 38.5 ft/min (11.58 m/min.) and then water quenched. The extruded rods were then drawn with 28.4% ROA (reduction of area) to a final diameter of 0.539 inch (13.7 mm) and then aged for 8 hours at 355 °F (179.4 °C), thereby producing T8 temper rods. The mechanical properties of the rods were then measured by obtaining tensile samples from the front and rear of every rod. The mechanical property results are summarized in Table 2, below. (Values are the average of duplicate specimens.)

Table 2 - Mechanical Properties of Ex, 1 Alloys

[0088] As shown, the new alloys realize significantly higher strengths than the conventional 6020 alloys and with generally similar ductility. Alloys 4-6 with higher silicon (>0.8 wt. %) and manganese (> 0.3 wt. %) realize significantly higher strength than the conventional 6020 alloys.

[0089] Particle counts were also conducted on SEM images and in accordance with the Microstructure Assessment Procedure, above. The particle count results are shown in Table 3, below. FIG. 2 shows the particle size distribution. The mean and D10-D90 values provided below are in micrometers.

Table 3 - Dispersoid Analysis - Example 1 Alloys

[0090] The particle counts are representative of the volume of dispersoids in the alloy product, including the volume of FeMn3Si2 dispersoids. As shown, the new alloys contain significantly more dispersoids than the conventional 6020 alloys but at generally similar dispersoid sizes. It is believed that the higher manganese, iron and/or silicon content at least partially contributes to the high volume fraction of dispersoids in the new aluminum alloy products. Such high dispersoid amounts may facilitate, among other things, the production of wrought aluminum alloy products in partially unrecrystallized or fully unrecrystallized form. Improved properties may accordingly be realized.

[0091] A microstructure analysis of the produced rods was also conducted. Specifically, one rod from Alloy 1-3, one rod from Alloys 4-6, and one rod of the 6020 alloys were subjected to EBSD imaging per the Microstructure Assessment Procedure, above. As shown in FIGS. 3A-3C, the standard 6020 alloys contained very little <111> microtexture having less than 3 vol. % of <111> microtexture, which is consistent with a fully recrystallized microstructure. Conversely, the new alloys having at least 0.15 wt. % Mn and 0.40 wt. % Fe realized significantly more <111> microtexture. Alloys 1-3 having about 0.66 wt. % Si, 0.42 wt. % Fe, and 0.18 wt. % Mn contained about 20 vol. % <111> microtexture, which is consistent with a partially unrecrystallized microstructure. Alloys 4-6 having about 0.81 wt. % Si, 0.45 wt. % Fe, and 0.32 wt. % Mn contained about 40 vol. % <111> microtexture, which is consistent with a fully unrecrystallized microstructure.

[0092] Example 2

[0093] Additional industrial scale billets were cast and homogenized as per Example 1, the composition of which is shown below in Table 4.

Table 4 - Composition of Ex, 2 Alloys (in wt. %)*

* The balance of the alloy was incidental elements and impurities, where the alloy contained not greater than 0.03 wt. % of any one impurity, and where the alloy contained not greater than 0.10 wt. %, in total, of all impurities.

[0094] A first set of the homogenized billets were preheated from room temperature to 940 °F (504 °C) and then extruded to a diameter of 1.031 inch (26.2 mm) at an extrusion speed of 50 ft/min (15.24 m/min), and then water quenched. The extruded rods were then drawn with a 14.6% ROA (reduction of area) to a final diameter of 0.952 inch (24.2 mm) and then aged at 355 °F (179.4 °C) for 8 hours thereby producing a first set of T8 temper rods (Alloys 7A). [0095] A second set of the homogenized billets were preheated from room temperature to 870 °F (465.6 °C) and then extruded to a diameter of 1.077 inch (27.3 mm) at an extrusion speed of 50 ft/min ( 15.24 m/min), and then water quenched. The extruded rods were then drawn with a 21.7% ROA (reduction of area) to a final diameter of 0.953 inch (24.2 mm) and then aged at 355 °F (179.4 °C) for 8 hours thereby producing T8 temper rods (Alloys 7B).

[0096] The mechanical properties of the rods were then measured by obtaining tensile samples from the front and rear of every rod. The mechanical property results are summarized in Table 5, below. (Values are the average of at least triplicate specimens.)

Table 5 - Mechanical Properties of Ex, 2 Alloys

[0097] It is believed that the high amount of dispersoids facilitated, among other things, the production of partially unrecrystallized or fully unrecrystallized rods, resulting in the improved mechanical properties. For instance, Alloy 7 contained 0.12 wt. % Cr as compared to the 0.05- 0.06 wt. % Cr of Alloys 1-6. The increased amount of chromium in Alloy 7 may be at least partially responsible for its significantly higher strength properties.

[0098] While various embodiments of the present disclosure have been described in detail, it is apparent that modifications and adaptations of those embodiments will occur to those skilled in the art. However, it is to be expressly understood that such modifications and adaptations are within the spirit and scope of the present disclosure.