High Fracture Toughness Aluminum-Copper-Lithium Sheet or Light-Gauge Plates Suitable for Fuselage Panels

Abstract

An aluminum alloy comprising 2.1 to 2.8 wt. % Cu, 1.1 to 1.7 wt. % Li, 0.1 to 0.8 wt. % Ag, 0.2 to 0.6 wt. % Mg, 0.2 to 0.6 wt. % Mn, a content of Fe and Si less or equal to 0.1 wt. % each, and a content of unavoidable impurities less than or equal to 0.05 wt. % each and 0.15 wt. % total, and the alloy being substantially zirconium free.

1 . An aluminum alloy rolled product comprising
 (a) from about 2.3 to about 2.5 wt. % Cu,   (b) from about 1.2 to about 1.6 wt. % Li,   (c) from about 0.1 to about 0.4 wt. % Ag,   (d) from about 0.2 to about 0.4 wt. % Mg,   (e) from about 0.2 to about 0.4 wt. % Mn,   
       a content of Fe and Si of less or equal to 0.05 wt. % each, a content of unavoidable impurities less than or equal to 0.05 wt. % each and 0.15 wt. % total, and the alloy being substantially zirconium free, wherein said zirconium is present an amount of not more than about 0.04 wt %. 
     
     
         2 . The aluminum alloy rolled product of  claim 1 , comprising (b) from about 1.3 to about 1.5 wt. % Li. 
     
     
         3 . The aluminum alloy rolled product of  claim 1 , comprising (c) from about 0.2 to about 0.4 wt. % Ag. 
     
     
         4 . The aluminum alloy rolled product of  claim 1 , comprising (d) from about 0.3 to about 0.4 wt. % Mg. 
     
     
         5 . The aluminum alloy rolled product of  claim 1 , comprising (e) from about 0.3 to about 0.4 wt. % Mn. 
     
     
         6 . The aluminum alloy rolled product of  claim 1 , comprising
 (a) from about 2.3 to about 2.5 wt. % Cu,   (b) from about 1.3 to about 1.5 wt. % Li,   (c) from about 0.2 to about 0.4 wt. % Ag,   (d) from about 0.3 to about 0.4 wt. % Mg, and   (e) from about 0.3 to about 0.4 wt. % Mn.   
     
     
         7 . An aluminum alloy product of  claim 1 , wherein said zirconium is less than or equal to 0.03 wt. %. 
     
     
         8 . An aluminum alloy product of  claim 1 , wherein said zirconium is less than or equal to 0.01 wt. %. 
     
     
         9 . An aircraft fuselage panel comprising an aluminum alloy product of  claim 1 . 
     
     
         10 . An aeronautical structural member comprising at least one aluminum alloy product of  claim 1 . 
     
     
         11 . A method for producing an aluminum alloy sheet or light gauge plate comprising a product of  claim 1 , said method comprising:
 (a) casting an ingot comprising
 (i) from about 2.3 to about 2.5 wt. % Cu, 
 (ii) from about 1.2 to about 1.6 wt. % Li, 
 (iii) from about 0.1 to about 0.4 wt. % Ag, 
 (iv) from about 0.2 to about 0.4 wt. % Mg, 
 (v) from about 0.2 to about 0.4 wt. % Mn, 
   
       a content of Fe and Si of less or equal to 0.05 wt. % each, a content of unavoidable impurities less than or equal to 0.05 wt. % each and 0.15 wt. % total, and the alloy being substantially zirconium free, wherein said zirconium is present an amount of not more than about 0.04 wt %,
 (b) homogenizing said ingot at 480-520° C. for about 5 to about 60 hours, 
 (c) hot rolling said ingot to a slab, with an hot rolling initial temperature of about 450° C. to about 490° C. and optionally cold rolling said slabs, 
 (d) solution heat treating said slabs at about 480° C. to about 520° C. for about 15 min to about 4 hours, 
 (e) quenching said slabs, 
 (f) stretching said slabs with a permanent set from about 1 to about 5%, 
 (g) aging said slab by heating at about 140° C. to about 170° C. for about 5 to about 80 hours, and 
 (h) resulting in a sheet or light gauge plate comprising a product of  claim 1 . 
 
     
     
         12 . The method of  claim 11 , wherein said ingot comprises (ii) from about 1.3 to about 1.5 wt. % Li. 
     
     
         13 . The method of  claim 11 , wherein said ingot comprises (iii) from about 0.2 to about 0.4 wt. % Ag. 
     
     
         14 . The method of  claim 11 , wherein said ingot comprises (iv) from about 0.3 to about 0.4 wt. % Mg. 
     
     
         15 . The method of  claim 11 , wherein said ingot comprises (v) from about 0.3 to about 0.4 wt. % Mn. 
     
     
         16 . The method of  claim 11 , wherein said ingot comprises
 (a) from about 2.3 to about 2.5 wt. % Cu,   (b) from about 1.3 to about 1.5 wt. % Li,   (c) from about 0.2 to about 0.4 wt. % Ag,   (d) from about 0.3 to about 0.4 wt. % Mg, and   (e) from about 0.3 to about 0.4 wt. % Mn.   
     
     
         17 . The method of  claim 11 , wherein said the zirconium in said ingot is less than or equal to 0.03 wt. %. 
     
     
         18 . The method of  claim 11 , wherein said the zirconium in said ingot is less than or equal to 0.01 wt. %.