6xxx aluminum alloys

Abstract

New 6xxx aluminum alloys having an improved combination of properties are disclosed. The new 6xxx aluminum alloy generally include 0.65-0.85 wt. % Si, 0.40-0.59 wt. % Mg, wherein (wt. % Mg)/(wt. % Si) is from 0.47 to 0.90, 0.05-0.35 wt. % Fe, 0.04-0.13 wt. % Mn, 0-0.20 wt. % Cu, 0-0.15 wt. % Cr, 0-0.15 wt. % Zr, 0-0.15 wt. % Ti, 0-0.10 wt. % Zn, 0-0.05 wt. % V, the balance being aluminum and impurities.

What is claimed is: 
     
         1 . A 6xxx aluminum alloy comprising:
 0.65-0.85 wt. % Si;   0.40-0.59 wt. % Mg;
 wherein (wt. % Mg)/(wt. % Si) is from 0.47 to 0.90; 
   0.05-0.35 wt. % Fe;   0.04-0.13 wt. % Mn;   0-0.20 wt. % Cu;   0-0.15 wt. % Cr;   0-0.15 wt. % Zr;   0-0.15 wt. % Ti;   0-0.10 wt. % Zn;   0-0.05 wt. % V;   the balance being aluminum and impurities.   
     
     
         2 . The 6xxx aluminum alloy of  claim 1 , wherein the 6xxx aluminum alloy includes at least 0.675 wt. % Si, or at least 0.70 wt. % Si. 
     
     
         3 . The 6xxx aluminum alloy of  claim 1 , wherein the 6xxx aluminum alloy includes not greater than 0.825 wt. % Si, or not greater than 0.80 wt. % Si. 
     
     
         4 . The 6xxx aluminum alloy of  claim 1 , wherein the 6xxx aluminum alloy includes at least 0.425 wt. % Mg, or at least 0.45 wt. % Mg, 0.475 wt. % Mg, or at least 0.50 wt. % Mg. 
     
     
         5 . The 6xxx aluminum alloy of  claim 1 , wherein the 6xxx aluminum alloy includes not greater than 0.57 wt. % Mg. 
     
     
         6 . The 6xxx aluminum alloy of  claim 1 , wherein the (wt. % Mg)/(wt. % Si) is at least 0.50, or at least 0.52, or at least 0.54, or at least 0.56, or at least 0.58, or at least 0.60. 
     
     
         7 . The 6xxx aluminum alloy of  claim 1 , wherein the (wt. % Mg)/(wt. % Si) is not greater than 0.88, or not greater than 0.86, or not greater than 0.84, or not greater than 0.82. 
     
     
         8 . The 6xxx aluminum alloy sheet of  claim 1 , wherein:
 the 6xxx aluminum alloy sheet product has a thickness of from 1.5 to 4.0 mm;   the 6xxx aluminum alloy sheet product has a predominately recrystallized microstructure;   the 6xxx aluminum alloy sheet product realizes a weighted average grain size of from 5 to 45 micrometers; and   the 6xxx aluminum alloy sheet product comprises at least 10% Cube texture.   
     
     
         9 . A 6xxx aluminum alloy comprising:
 0.70-0.80 wt. % Si;   0.49-0.59 wt. % Mg;
 wherein (wt. % Mg)/(wt. % Si) is from 0.61 to 0.84; 
   0.09-0.29 wt. % Fe;   0.06-0.10 wt. % Mn;   0.09-0.17 wt. % Cu;   0.01-0.05 wt. % Cr;   0.01-0.05 wt. % Ti;   not greater than 0.05 wt. % Zn;   not greater than 0.05 wt. % V;   not greater than 0.05 wt. % Zr;   the balance being aluminum and impurities.   
     
     
         10 . A method comprising:
 (a) casting a 6xxx aluminum alloy as a cast product, wherein the 6xxx aluminum alloy comprises:
 0.65-0.85 wt. % Si; 
 0.40-0.59 wt. % Mg;
 wherein (wt. % Mg)/(wt. % Si) is from 0.47 to 0.90; 
 
 0.05-0.35 wt. % Fe; 
 0.04-0.13 wt. % Mn; 
 0-0.20 wt. % Cu; 
 0-0.15 wt. % Cr; 
 0-0.15 wt. % Zr; 
 0-0.15 wt. % Ti; 
 0-0.10 wt. % Zn; 
 0-0.05 wt. % V; 
 the balance being aluminum and impurities; 
   (b) hot rolling the cast product to an intermediate gauge product, wherein either:
 (i) an exit temperature of the intermediate gauge product is not greater than 290° C. and wherein an anneal of the intermediate gauge product is completed after the hot rolling; or 
 (ii) an exit temperature of the intermediate gauge product is from 400 to 480° C.; 
   (c) cold rolling the intermediate gauge product to a final gauge product;
 wherein the intermediate gauge product has an as-received thickness; 
 wherein the final gauge product has a final thickness; 
 wherein the cold rolling comprises reducing the as-received thickness by at least 50% to achieve the final thickness. 
   
     
     
         11 . The method of  claim 10 , comprising:
 after the cold rolling, solution heat treating and then quenching the final gauge product;   wherein the solution heat treating comprises heating the final gauge product to a peak metal temperature;   wherein the peak metal temperature is not greater than 593° C.   
     
     
         12 . The method of  claim 11 , wherein the final gauge product realizes a predominately recrystallized microstructure. 
     
     
         13 . The method of  claim 12 , wherein the final gauge product realizes an area weighted average grain size of not greater than 45 micrometers, or not greater than 40 micrometers. 
     
     
         14 . The method of  claim 13 , wherein the final gauge product comprises at least 10% Cube texture.