High-strength, corrosion resistant aluminum alloys for use as fin stock and methods of making the same

Abstract

Disclosed herein are high-strength, highly formable, and corrosion resistant aluminum alloys, methods of making and processing such alloys, and products prepared from such alloys. More particularly, disclosed are novel aluminum alloys exhibiting improved mechanical strength, formability, and corrosion resistance. The alloys can be used as fin stock in industrial applications, including in heat exchangers.

1 . An aluminum alloy product, comprising about 0.7-3.0 wt. % Zn, about 0.15-0.35 wt. % Si, about 0.25-0.65 wt. % Fe, about 0.05-0.20 wt. % Cu, about 0.75-1.50 wt. % Mn, about 0.60-1.50 wt. % Mg, up to about 0.10 wt. % Cr, up to about 0.10 wt. % Ti, and up to about 0.15 wt. % of impurities, with the remainder as Al, wherein the aluminum alloy product has a gauge of 0.5 mm or less. 
     
     
         2 . The aluminum alloy product of  claim 1 , comprising about 1.0-2.5 wt. % Zn, about 0.2-0.35 wt. % Si, about 0.35-0.60 wt. % Fe, about 0.10-0.20 wt. % Cu, about 0.75-1.25 wt. % Mn, about 0.90-1.30 wt. % Mg, up to about 0.05 wt. % Cr, up to about 0.05 wt. % Ti, and up to about 0.15 wt. % of impurities, with the remainder as Al. 
     
     
         3 . The aluminum alloy product of  claim 1 , comprising about 1.5-2.5 wt. % Zn, about 0.17-0.33 wt. % Si, about 0.30-0.55 wt. % Fe, about 0.15-0.20 wt. % Cu, about 0.80-1.00 wt. % Mn, about 1.00-1.25 wt. % Mg, up to about 0.05 wt. % Cr, up to about 0.05 wt. % Ti, and up to about 0.15 wt. % of impurities, with the remainder as Al. 
     
     
         4 . The aluminum alloy product of  claim 1 , comprising about 0.9-2.6 wt. % Zn, about 0.2-0.33 wt. % Si, about 0.49-0.6 wt. % Fe, about 0.15-0.19 wt. % Cu, about 0.79-0.94 wt. % Mn, about 1.13-1.27 wt. % Mg, up to about 0.05 wt. % Cr, up to about 0.05 wt. % Ti, and up to about 0.15 wt. % of impurities, with the remainder as Al. 
     
     
         5 . The aluminum alloy product of  claim 1 , comprising about 1.4-1.6 wt. % Zn, about 0.2-0.33 wt. % Si, about 0.49-0.6 wt. % Fe, about 0.15-0.19 wt. % Cu, about 0.79-0.94 wt. % Mn, about 1.13-1.27 wt. % Mg, up to about 0.05 wt. % Cr, up to about 0.05 wt. % Ti, and up to about 0.15 wt. % of impurities, with the remainder as Al. 
     
     
         6 . The aluminum alloy product of  claim 1 , wherein the aluminum alloy is produced by direct chill casting or by continuous casting. 
     
     
         7 . The aluminum alloy product of  claim 1 , wherein the aluminum alloy is produced by homogenization, hot rolling, cold rolling, and annealing. 
     
     
         8 . The aluminum alloy product of  claim 1 , wherein the aluminum alloy is in an H temper or an O temper. 
     
     
         9 . The aluminum alloy product of  claim 1 , wherein a yield strength of the aluminum alloy is at least about 70 MPa. 
     
     
         10 . The aluminum alloy product of  claim 1 , wherein an ultimate tensile strength of the aluminum alloy is at least about 170 MPa. 
     
     
         11 . The aluminum alloy product of  claim 1 , wherein the aluminum alloy comprises an electrical conductivity above about 37% based on the international annealed copper standard (IACS). 
     
     
         12 . The aluminum alloy product of  claim 1 , wherein the aluminum alloy comprises a corrosion potential of from about −740 mV to about −850 mV. 
     
     
         13 . A fin stock comprising the aluminum alloy of  claim 1 . 
     
     
         14 . The fin stock of  claim 13 , wherein a gauge of the fin stock is 1.0 mm or less. 
     
     
         15 . The fin stock of  claim 13 , wherein a gauge of the fin stock is 0.15 mm or less. 
     
     
         16 . An article comprising a tube and a fin, wherein the fin comprises the fin stock according to  claim 13 . 
     
     
         17 . A method of producing a metal product, comprising:
 casting an aluminum alloy to form a cast aluminum alloy, wherein the aluminum alloy comprises about 0.7-3.0 wt. % Zn, about 0.15-0.35 wt. % Si, about 0.25-0.65 wt. % Fe, about 0.05-0.20 wt. % Cu, about 0.75-1.50 wt. % Mn, about 0.50-1.50 wt. % Mg, up to about 0.05 wt. % Cr, up to about 0.05 wt. % Ti, and up to about 0.15 wt. % of impurities, with the remainder as Al;   homogenizing the cast aluminum alloy;   hot rolling the cast aluminum alloy to produce a rolled product; and   cold rolling the rolled product to a final gauge product.   
     
     
         18 . The method of  claim 17 , further comprising annealing the final gauge product. 
     
     
         19 - 20 . (canceled) 
     
     
         21 . The aluminum alloy product of  claim 1 , wherein the gauge is about 0.2 mm or less. 
     
     
         22 . The aluminum alloy product of  claim 1 , wherein the gauge is about 0.15 mm or less. 
     
     
         23 . The aluminum alloy product of  claim 1 , wherein the aluminum alloy product is a heat exchanger fin.