High-strength 6xxx extrusion alloys

Abstract

Some embodiments of the present disclosure relate to a 6xxx aluminum alloy having: silicon (Si) in an amount of 0.70 wt % to 1.1 wt % based on a total weight of the 6xxx aluminum alloy; magnesium (Mg) in an amount of 0.75 wt % to 1.15 wt % based on the total weight of the 6xxx aluminum alloy; a weight ratio of Mg to Si in the 6xxx aluminum alloy from 0.68:1.0 to 1.65:1.0; and copper (Cu) in an amount of 0.30 wt % to 0.8 wt % based on the total weight of the 6xxx aluminum alloy. Some embodiments of the present disclosure further relate to a method including steps of: casting an exemplary 6xxx aluminum alloy, homogenizing the exemplary 6xxx aluminum alloy; extruding the exemplary 6xxx aluminum alloy; and aging the 6xxx aluminum alloy.

1 . A 6xxx aluminum alloy consisting of:
 silicon (Si) in an amount of 0.70 wt % to 1.1 wt % based on a total weight of the 6xxx aluminum alloy;   magnesium (Mg) in an amount of 0.75 wt % to 1.15 wt % based on the total weight of the 6xxx aluminum alloy;   wherein a weight ratio of Mg to Si in the 6xxx aluminum alloy is from 0.68:1.0 to 1.65:1.0,   wherein a sum total of the Si and the Mg is present in an amount of from 1.5% to 2.2% based on the total weight of the 6xxx aluminum alloy;   copper (Cu) in an amount of 0.30 wt % to 0.8 wt % based on the total weight of the 6xxx aluminum alloy;   iron (Fe) in an amount of 0.12 wt % to 0.3 wt % based on the total weight of the 6xxx aluminum alloy;   manganese (Mn) in an amount of 0.25 wt % to 0.65 wt % based on the total weight of the 6xxx aluminum alloy;   zirconium (Zr) in an amount of at most 0.2 wt % based on the total weight of the 6xxx aluminum alloy;   chromium (Cr) in an amount of at most 0.2 wt % based on the total weight of the 6xxx aluminum alloy;   the balance aluminum (Al) and other elements;   wherein each of the other elements is present in amount of less than or equal to 0.05 wt % based on the total weight of the 6xxx aluminum alloy; and   wherein a sum total of the other elements is less than 0.15% wt % based on the total weight of the 6xxx aluminum alloy.   
     
     
         2 . The 6xxx aluminum alloy of  claim 1 , wherein the other elements are selected from the group consisting of: titanium (Ti), boron (B), zinc (Zn), molybdenum (Mo), nickel (Ni), or any combination thereof. 
     
     
         3 . The 6xxx aluminum alloy of  claim 1 , wherein up to 0.95 wt % of Mg based on the total weight of the 6xxx aluminum alloy is in a Mg 2 Si phase. 
     
     
         4 . The 6xxx aluminum alloy of  claim 1 , wherein up to 0.5 wt % of Si based on the total weight of the 6xxx aluminum alloy is in the Mg 2 Si phase. 
     
     
         5 . The 6xxx aluminum alloy of  claim 1 , wherein 0.16 wt % to 0.78 wt % of Mg based on the total weight of the 6xxx aluminum alloy is in an Al 5 Cu 2 Mg 8 Si 5  (“Q”) phase. 
     
     
         6 . The 6xxx aluminum alloy of  claim 1 , wherein 0.14 wt % to 0.68 wt % of Si based on the total weight of the 6xxx aluminum alloy is in the Q phase. 
     
     
         7 . The 6xxx aluminum alloy of  claim 1 , wherein 0.1 wt % to 0.5 wt % of Cu based on the total weight of the 6xxx aluminum alloy is in the Q phase. 
     
     
         8 . The 6xxx aluminum alloy of  claim 1 , wherein 0.11 wt % to 0.54 wt % of Cu based on the total weight of the 6xxx aluminum alloy is in an Al 2 Cu phase. 
     
     
         9 . (canceled) 
     
     
         10 . (canceled) 
     
     
         11 . The 6xxx aluminum alloy of  claim 1 , having a yield strength of 350 MPa to 400 MPa. 
     
     
         12 . (canceled) 
     
     
         13 . A 6xxx aluminum alloy consisting essentially of:
 silicon (Si) in an amount of 0.70 wt % to 1.1 wt % based on a total weight of the 6xxx aluminum alloy;   magnesium (Mg) in an amount of 0.75 wt % to 1.15 wt % based on the total weight of the 6xxx aluminum alloy;   wherein a sum total of the Si and the Mg is present in an amount of from 1.5% to 2.2% based on the total weight of the 6xxx aluminum alloy;   wherein a weight ratio of Mg to Si in the 6xxx aluminum alloy is from 0.68:1.0 to 1.65:1.0,   copper (Cu) in an amount of 0.30 wt % to 0.8 wt % based on the total weight of the 6xxx aluminum alloy;   iron (Fe) in an amount of 0.12 wt % to 0.3 wt % based on the total weight of the 6xxx aluminum alloy;   manganese (Mn) in an amount of 0.25 wt % to 0.65 wt % based on the total weight of the 6xxx aluminum alloy;   aluminum (Al);   optionally, zirconium (Zr) in an amount of at most 0.2 wt % based on the total weight of the 6xxx aluminum alloy;   optionally, chromium (Cr) in an amount of at most 0.2 wt % based on the total weight of the 6xxx aluminum alloy; and   optionally, other elements.   
     
     
         14 . (canceled) 
     
     
         15 . (canceled) 
     
     
         16 . A 6xxx aluminum alloy comprising:
 silicon (Si) in an amount of 0.70 wt % to 1.1 wt % based on a total weight of the 6xxx aluminum alloy;   magnesium (Mg) in an amount of 0.75 wt % to 1.15 wt % based on the total weight of the 6xxx aluminum alloy;   wherein a weight ratio of Mg to Si in the 6xxx aluminum alloy is from 0.68:1.0 to 1.65:1.0; and   copper (Cu) in an amount of 0.30 wt % to 0.8 wt % based on the total weight of the 6xxx aluminum alloy.   
     
     
         17 . The 6xxx aluminum alloy of  claim 16 , wherein a sum total of the Si and the Mg is present in an amount of from 1.5% to 2.2% based on the total weight of the 6xxx aluminum alloy. 
     
     
         18 . The 6xxx aluminum alloy of  claim 16 , further comprising iron (Fe) in an amount of 0.12 wt % to 0.3 wt % based on the total weight of the 6xxx aluminum alloy. 
     
     
         19 . The 6xxx aluminum alloy of  claim 16 , further comprising manganese (Mn) in an amount of 0.25 wt % to 0.65 wt % based on the total weight of the 6xxx aluminum alloy. 
     
     
         20 . The 6xxx aluminum alloy of  claim 16 , further comprising zirconium (Zr) in an amount of at most 0.2 wt % based on the total weight of the 6xxx aluminum alloy. 
     
     
         21 . The 6xxx aluminum alloy of  claim 16 , further comprising chromium (Cr) in an amount of at most 0.2 wt % based on the total weight of the 6xxx aluminum alloy. 
     
     
         22 . The 6xxx aluminum alloy of  claim 16 , further comprising other elements in an amount of less than 0.05 wt % based on the total weight of the 6xxx aluminum alloy. 
     
     
         23 . The 6xxx aluminum alloy of  claim 22 , wherein a total of the other elements is less than 0.15 wt % based on the total weight of the 6xxx aluminum alloy. 
     
     
         24 . The 6xxx aluminum alloy of  claim 23 , wherein the other elements are chosen from: titanium (Ti), boron (B), zinc (Zn), molybdenum (Mo), nickel (Ni), or any combination thereof. 
     
     
         25 . A method comprising:
 casting a 6xxx aluminum alloy,
 wherein the 6xxx aluminum alloy comprises: 
   silicon (Si) in an amount of 0.70 wt % to 1.1 wt % based on a total weight of the 6xxx aluminum alloy;   magnesium (Mg) in an amount of 0.75 wt % to 1.15 wt % based on the total weight of the 6xxx aluminum alloy;   wherein a weight ratio of Mg to Si in the 6xxx aluminum alloy is from 0.68:1.0 to 1.65:1.0; and   copper (Cu) in an amount of 0.30 wt % to 0.8 wt % based on the total weight of the 6xxx aluminum alloy;
 homogenizing the 6xxx aluminum alloy; 
 extruding the 6xxx aluminum alloy; and 
 aging the 6xxx aluminum alloy. 
   
     
     
         26 . The method of  claim 25 , wherein homogenizing comprises heating the 6xxx aluminum alloy to a homogenization temperature (T H ) that is less than a solidus temperature (T S ) of the 6xxx aluminum alloy. 
     
     
         27 . The method of  claim 25 , wherein homogenizing comprises heating the 6xxx aluminum alloy to T H  that exceeds a solvus temperature (T Σ ) of at least one of: a Mg 2 Si phase of the 6xxx aluminum alloy, a Al 5 Cu 2 Mg 8 Si 5  (“Q”) phase of the 6xxx aluminum alloy, an Al 2 Cu phase of the 6xxx aluminum alloy, or any combination thereof. 
     
     
         28 . The method of  claim 27 , wherein the T Σ  of at least one of the Mg 2 Si phase, the Q phase, or any combination thereof ranges from 520° C. to 590° C. 
     
     
         29 . The method of  claim 28 , wherein the T H  ranges from 530° C. to 600° C. 
     
     
         30 . The method of  claim 29 , wherein the T S  of the 6xxx aluminum alloy ranges from 540° C. to 610° C. 
     
     
         31 . The method of  claim 30 , wherein the homogenizing comprises heating the 6xxx aluminum alloy from room temperature to the T H  for 1 to 10 hrs. 
     
     
         32 . (canceled) 
     
     
         33 . The method of  claim 25 , wherein the homogenizing further comprises air-cooling the 6xxx aluminum alloy to room temperature. 
     
     
         34 . The method of  claim 25 , wherein the extruding is performed at an exit temperature T E , wherein the T E  is controlled to a range of 450° C. to 570° C. 
     
     
         35 . The method of  claim 25 , further comprising quenching the 6xxx aluminum alloy. 
     
     
         36 . (canceled) 
     
     
         37 . (canceled) 
     
     
         38 . (canceled) 
     
     
         39 . The method of  claim 25 , wherein aging comprises an artificial aging step, wherein the artificial aging step is performed for 1 to 32 hours at an artificial aging temperature (T AA ) of 150° C. to 210° C.