Aluminum alloys with high strength and cosmetic appeal

Abstract

The disclosure provides aluminum alloys having varying ranges of alloying elements and properties.

1 . An aluminum alloy comprising:
 at least 3.4 wt % Zn;   1.3 to 2.1 wt % Mg;   no greater than 0.06 wt % Cu;   no greater than 0.06 wt % Zr;   0.06 to 0.08 wt % Fe;   at least 0.04 wt % Si; and   the balance is aluminum and incidental impurities.   
     
     
         2 . The aluminum alloy according to  claim 1 , comprising
 1.3 to 1.7 wt % Mg.   
     
     
         3 . The alloy according to  claim 1 , comprising:
 no greater than 0.02 wt % Mn;   no greater than 0.02 wt % Cr;   no greater than 0.02 wt % Ti;   no greater than 0.02 wt % Ga;   no greater than 0.02 wt % Sn;   no greater than 0.03 wt % total of Mn and Cr;   no greater than 0.02 wt % of any one additional element; and   no greater than 0.10 wt % total of additional elements.   
     
     
         4 . The alloy according to  claim 1 , wherein the stress corrosion cracking of the alloy is greater than 12 days to failure measured according to G30/G44 ASTM standards. 
     
     
         5 . The alloy according to  claim 1 , wherein the alloy comprises equiaxed grains, wherein the alloy has an average grain aspect ratio less than or equal to 1:1.2. 
     
     
         6 . The alloy according to  claim 1 , wherein the Charpy impact energy in the L-T orientation is greater than or equal to 11 J/cm 2 . 
     
     
         7 . The alloy according to  claim 1 , wherein the alloy has a yield strength of about at least 300 MPa. 
     
     
         8 . A method for producing an aluminum alloy, the method comprising:
 forming a melt that comprises the alloy of  claim 1 ;   cooling the melt to room temperature;   homogenizing the cooled alloy by heating to a first elevated temperature;   hot-working the homogenized alloy;   solution treating the hot-worked alloy at a second elevated temperature; and   aging the solution treated alloy at a third elevated temperature for a period of time.   
     
     
         9 . An article comprising the alloy according to  claim 1 .