Aluminum alloys having silicon, magnesium, copper and zinc

Abstract

New aluminum alloys are disclosed. The new aluminum alloys may include from 0.70 to 1.4 wt. % Si, from 0.70 to 1.3 wt. % Mg, wherein (wt. % Mg)/(wt. % Si) is not greater than 1.40, from 0.70 - 3.0 wt. % Zn, from 0.55 to 1.3 wt. % Cu, wherein the total amount of Si+Mg+Zn+Cu is not greater than 4.25 wt. %, from 0.01 to 0.30 wt. % Fe, up to 0.70 wt. % Mn, up to 0.15 wt. % Cr, up to 0.20 wt. % Zr, up to 0.20 wt. % V, and up to 0.25 wt. % Ti, the balance being aluminum, optional incidental elements and impurities. The new aluminum alloys may realize an improved combination of properties, such as an improved combination of strength, formability and/or corrosion resistance.

What is claimed is: 
     
         1 . A aluminum alloy sheet product comprising:
 from 0.70 to 1.4 wt. % Si;   from 0.70 to 1.3 wt. % Mg;
 wherein (wt. % Mg)/(wt. % Si) is not greater than 1.4:1; 
   from 0.70 to 3.0 wt. % Zn;   from 0.55 to 1.3 wt. % Cu;
 wherein the total amount of Si+Mg+Zn+Cu is not greater than 4.25 wt. %; 
   from 0.01 to 0.30 wt. % Fe;   up to 0.70 wt. % Mn;   up to 0.15 wt. % Cr;   up to 0.20 wt. % Zr;   up to 0.20 wt. % V;   up to 0.25 wt. % Ti;   the balance being aluminum, optional incidental elements and impurities;   wherein the aluminum alloy sheet product has a thickness of from 1.0 to 4.0 mm;   wherein the aluminum sheet product realizes at least one of the following properties:   (i) a TYS-LT of not greater than 155 MPa at 7 days of natural aging (“TYS-7NA”);   (ii) a TYS-LT of not greater than 175 MPa at 90 days of natural aging (“TYS-90NA”);   (iii) a (TYS-90NA) minus (TYS-7NA) of not greater than 20 MPa;   (iv) a TYS-LT of at least 235 MPa when naturally aged for 30 days and then paint baked at 180° C. for 20 minutes;   (v) a TYS-LT of at least 230 MPa when naturally aged for 90 days and then paint baked at 180° C. for 20 minutes; and   (vi) a TYS-LT of at least 350 MPa when naturally aged for 30 days and then artificially aged at 180° C. for 8 hours.   
     
     
         2 . The aluminum alloy sheet product of  claim 1 , wherein the aluminum alloy includes at least 0.75 wt. % Si. 
     
     
         3 . The aluminum alloy sheet product of  claim 1 , wherein the aluminum alloy includes not greater than 1.35 wt. % Si. 
     
     
         4 . The aluminum alloy sheet product of  claim 1 , wherein the aluminum alloy includes at least 0.75 wt. % Mg. 
     
     
         5 . The aluminum alloy sheet product of  claim 1 , wherein the aluminum alloy includes not greater than 1.25 wt. % Mg. 
     
     
         6 . The aluminum alloy sheet product of  claim 1 , wherein (wt. % Mg)/(wt. % Si) is not greater than 1.3:1. 
     
     
         7 . The aluminum alloy sheet product of  claim 1 , wherein (wt. % Mg)/(wt. % Si) is at least 0.7:1. 
     
     
         8 . The aluminum alloy sheet product of  claim 1 , wherein the aluminum alloy includes at least 1.0 wt. % Zn. 
     
     
         9 . The aluminum alloy sheet product of  claim 1 , wherein the aluminum alloy includes not greater than 2.8 wt. % Zn. 
     
     
         10 . The aluminum alloy sheet product of  claim 1 , wherein the aluminum alloy includes at least 0.60 wt. % Cu. 
     
     
         11 . The aluminum alloy sheet product of  claim 1 , wherein the aluminum alloy includes not greater than 1.25 wt. % Cu. 
     
     
         12 . The aluminum alloy sheet product of  claim 1 , wherein the aluminum alloy includes at least 0.05 wt. % Mn. 
     
     
         13 . An automotive sheet product made from the aluminum alloy sheet product of  claim 1 . 
     
     
         14 . An aluminum alloy sheet product comprising:
 from 0.85 to 1.05 wt. % Si;   from 0.80 to 1.10 wt. % Mg;   from 0.70 to 1.8 wt. % Zn;   from 0.70 to 1.05 wt. % Cu;
 wherein the total amount of Si+Mg+Zn+Cu is not greater than 4.25 wt. %; 
   from 0.01 to 0.30 wt. % Fe;   up to 0.50 wt. % Mn;   up to 0.15 wt. % Cr;   up to 0.20 wt. % Zr;   up to 0.20 wt. % V;   up to 0.25 wt. % Ti;   the balance being aluminum, optional incidental elements and impurities;   wherein the aluminum alloy sheet product has a thickness of from 1.0 to 4.0 mm.