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

Abstract

Disclosed herein are high strength, corrosion resistant, and sag 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.

What is claimed is: 
     
         1 . An aluminum alloy comprising 0.20-1.30 wt. % Zn, 0.30-1.25 wt. % Si, 0-0.50 wt. % Fe, 0-0.20 wt. % Cu, 1.00-2.00 wt. % Mn, 0-0.10 wt. % Mg, up to 0.10 wt. % Cr, up to 0.10 wt. % Ti, and up to 0.15 wt. % of impurities, and Al. 
     
     
         2 . The aluminum alloy of  claim 1 , comprising 0.30-1.10 wt. % Zn, 0.35-1.20 wt. % Si, 0.01-0.40 wt. % Fe, 0.001-0.15 wt. % Cu, 1.20-1.80 wt. % Mn, 0-0.08 wt. % Mg, up to 0.08 wt. % Cr, up to 0.08 wt. % Ti, and up to 0.15 wt. % of impurities, and Al. 
     
     
         3 . The aluminum alloy of  claim 1 , comprising 0.35-1.00 wt. % Zn, 0.50-1.10 wt. % Si, 0.05-0.35 wt. % Fe, 0.01-0.10 wt. % Cu, 1.30-1.70 wt. % Mn, 0-0.05 wt. % Mg, up to 0.05 wt. % Cr, up to 0.05 wt. % Ti, and up to 0.15 wt. % of impurities, and Al. 
     
     
         4 . The aluminum alloy of  claim 1 , comprising 0.50-0.90 wt. % Zn, 0.80-1.10 wt. % Si, 0.05-0.30 wt. % Fe, 0.01-0.05 wt. % Cu, 1.30-1.50 wt. % Mn, 0.001-0.02 wt. % Mg, up to 0.05 wt. % Cr, up to 0.05 wt. % Ti, and up to 0.15 wt. % of impurities, and Al. 
     
     
         5 . The aluminum alloy of  claim 1 , comprising 0.75-0.85 wt. %, Zn, 0.80-0.90 wt. % Si, 0-0.30 wt. % Fe, 0-0.03 wt. % Cu, 1.35-1.50 wt. %, Mn, 0-0.05 wt. % Mg, up to 0.01 wt. % Cr, up to 0.03 wt. % Ti, and up to 0.15 wt. % of impurities, and Al. 
     
     
         6 . The aluminum alloy of  claim 1 , wherein the aluminum alloy is in an H temper. 
     
     
         7 . The aluminum alloy of  claim 6 , wherein an ultimate tensile strength of the aluminum alloy is at least 140 MPa. 
     
     
         8 . The aluminum alloy of  claim 6 , wherein a yield strength of the aluminum alloy is at least 155 MPa. 
     
     
         9 . The aluminum alloy of  claim 6 , wherein the aluminum alloy comprises an electrical conductivity above 50% based on the international annealed copper standard (IACS). 
     
     
         10 . The aluminum alloy of  claim 1 , wherein the aluminum alloy comprises a corrosion potential of from −700 mV to −800 mV. 
     
     
         11 . The aluminum alloy of  claim 1 , wherein the aluminum alloy comprises 0.80-0.90 wt. % Si, up to 0.30 wt. % Fe, up to 0.03 wt. % Cu, 1.35-1.50 wt. % Mn, up to 0.05 wt. % Mg, 0.75-0.85 wt. % Zn, up to 0.01 wt. % Cr, up to 0.03 wt. % Ti, up to 0.15 wt. % of impurities, and Al, wherein the aluminum alloy has a ultimate tensile strength from 160 MPa to 180 MPa, a yield strength from 150 MPa to 160 MPa, an elongation from 2% to 2.50%, and a conductivity from 55% IACS to 60% IACS. 
     
     
         12 . The aluminum alloy of  claim 1 , wherein a final gauge of the aluminum alloy is less than 0.10 mm. 
     
     
         13 . The aluminum alloy of  claim 1 , wherein the aluminum alloy has a sag resistance less than 35 mm, when measured on a sample having a length of 35 mm. 
     
     
         14 . A fin stock comprising the aluminum alloy of  claim 1 . 
     
     
         15 . An aluminum alloy product comprising a tube and a fin, wherein the fin comprises the fin stock according to  claim 14 . 
     
     
         16 . A method of producing an aluminum alloy product, the method comprising:
 casting an aluminum alloy to form a cast aluminum alloy, wherein the aluminum alloy comprises 0.20-1.30 wt. % Zn, 0.30-1.25 wt. % Si, 0-0.50 wt. % Fe, 0-0.20 wt. % Cu, 1.00-2.00 wt. % Mn, 0-0.10 wt. % Mg, up to 0.10 wt. % Cr, up to 0.10 wt. % Ti, and up to 0.15 wt. % of impurities, and Al;   preheating the cast aluminum alloy;   hot rolling the cast aluminum alloy to produce an aluminum alloy product;   cold rolling, in a first cold rolling step, the aluminum alloy to produce to an intermediate gauge aluminum alloy product;   inter-annealing the intermediate gauge aluminum alloy product; and   cold rolling, in a second cold rolling step, the intermediate gauge aluminum alloy product to a final gauge aluminum alloy product in an H temper.   
     
     
         17 . The method of  claim 16 , wherein the final gauge aluminum alloy product has an ultimate tensile strength of at least 140 MPa, a yield strength of at least 155 MPa, and an electrical conductivity of at least 50% based on the international annealed copper standard (IACS). 
     
     
         18 . The method of  claim 16 , further comprising brazing the final gauge aluminum alloy product to produce a brazed aluminum alloy product. 
     
     
         19 . The method of  claim 18 , the brazed aluminum alloy product has an ultimate tensile strength of at least 100 MPa, a yield strength of at least 45 MPa, and an electrical conductivity of at least 45% based on the international annealed copper standard (IACS). 
     
     
         20 . The method of  claim 16 , wherein the final gauge aluminum alloy product has final gauge less than 0.10 mm. 
     
     
         21 . An aluminum alloy product, wherein the aluminum alloy product is prepared by the method of  claim 16 .