New 6xxx aluminum alloys

Abstract

New 6xxx aluminum alloy products are disclosed. The new 6xxx aluminum alloy products may include tin and 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.

What is claimed is: 
     
         1 . A 6xxx aluminum alloy product comprising:
 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;   up to 0.04 wt. % Pb;   the balance being aluminum, optional incidental elements and impurities;   
       wherein the 6xxx aluminum alloy product comprises a dispersoid area fraction (f) of at least 0.30%, wherein the dispersoids comprise FeMn 3 Si 2  dispersoids. 
     
     
         2 . The 6xxx aluminum alloy product of  claim 1 , wherein the 6xxx aluminum alloy product includes from 0.80 wt. % Sn to 1.30 wt. % Sn. 
     
     
         3 . The 6xxx aluminum alloy product of  claim 1 , wherein (wt. % Si)+(wt. % Mn)+(wt. % Fe) is at least 1.0 wt. %. 
     
     
         4 . The 6xxx aluminum alloy product of  claim 1 , wherein the 6xxx aluminum alloy product includes not greater than 0.20 wt. % Bi. 
     
     
         5 . The 6xxx aluminum alloy product of  claim 1 , wherein the 6xxx aluminum alloy product includes not greater than 0.20 wt. % In. 
     
     
         6 . The 6xxx aluminum alloy product of  claim 1 , wherein the 6xxx aluminum alloy product includes not greater than 0.005 wt. % Pb. 
     
     
         7 . The 6xxx aluminum alloy product of  claim 1 , wherein a mean (average) dispersoid size is from 0.05 to 0.20 micrometers. 
     
     
         8 . The 6xxx aluminum alloy product of  claim 1 , wherein a D90 of the dispersoids is not greater than 0.30 micrometers, or not greater than 0.27 micrometers, or not greater than 0.24 micrometers, or not greater than 0.21 micrometers, or not greater than 0.19 micrometers, or not greater than 0.18 micrometers. 
     
     
         9 . The 6xxx aluminum alloy product of  claim 1 , wherein a D10 of the dispersoids is at least 0.02 micrometers, or at least 0.03 micrometers, or at least 0.04 micrometers. 
     
     
         10 . The 6xxx aluminum alloy product of  claim 1 , wherein the 6xxx aluminum alloy product comprises at least 3 vol. % <111> microtexture. 
     
     
         11 . The 6xxx aluminum alloy product of  claim 1 , wherein the 6xxx aluminum alloy product is a sheet, plate, extrusion or forging. 
     
     
         12 . The 6xxx aluminum alloy product of  claim 1 , wherein the 6xxx aluminum alloy product is an extrusion. 
     
     
         13 . The 6xxx aluminum alloy product of  claim 12 , wherein the extrusion is a rod. 
     
     
         14 . A method comprising:
 (a) casting a billet of the 6xxx aluminum alloy, wherein the 6xxx aluminum alloy comprises:
 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; 
 up to 0.04 wt. % Pb; 
 the balance being aluminum, optional incidental elements and impurities; 
   (b) pre-heating the billet to an extrusion temperature, wherein the extrusion temperature is from 810° F. to 960° F.; and   (c) extruding the billet into an extruded product.   
     
     
         15 . The method of  claim 14 , comprising quenching the extruded product during the extruding step. 
     
     
         16 . The method of  claim 14 , comprising, after the extruding step, solution heat treating and then quenching the extruded product. 
     
     
         17 . The method of  claim 16 , comprising, after the quenching, artificially aging the extruded product. 
     
     
         18 . The method of  claim 1 , wherein the extrusion speed is from 40 to 70 feet per minute. 
     
     
         19 . The method of  claim 1 , wherein the extruded product is devoid of visually apparent surface defects.