Aluminum alloy with additions of copper, lithium and at least one alkali or rare earth metal, and method of manufacturing the same

Abstract

An aluminum alloy including aluminum, about 1.8 to about 5.6 percent by weight copper, about 0.6 to about 2.6 percent by weight lithium, and at least one of lanthanum up to about 1.5 percent by weight, strontium up to about 1.5 percent by weight, cerium up to about 1.5 percent by weight and praseodymium up to about 1.5 percent by weight.

What is claimed is: 
     
         1 . An aluminum alloy comprising:
 aluminum;   about 1.8 to about 5.6 percent by weight copper;   about 0.6 to about 2.6 percent by weight lithium; and   at least one of:
 lanthanum up to about 1.5 percent by weight; 
 strontium up to about 1.5 percent by weight; 
 cerium up to about 1.5 percent by weight; and 
 praseodymium up to about 1.5 percent by weight. 
   
     
     
         2 . The aluminum alloy of  claim 1  comprising at least two of said lanthanum, said strontium, said cerium and said praseodymium. 
     
     
         3 . The aluminum alloy of  claim 1  further comprising silicon in a non-zero quantity up to about 0.20 percent by weight. 
     
     
         4 . The aluminum alloy of  claim 1  further comprising iron in a non-zero quantity up to about 0.30 percent by weight. 
     
     
         5 . The aluminum alloy of  claim 1  further comprising manganese in a non-zero quantity up to about 0.6 percent by weight. 
     
     
         6 . The aluminum alloy of  claim 1  further comprising magnesium in a non-zero quantity up to about 1.9 percent by weight. 
     
     
         7 . The aluminum alloy of  claim 1  further comprising chromium in a non-zero quantity up to about 0.10 percent by weight. 
     
     
         8 . The aluminum alloy of  claim 1  further comprising zinc in a non-zero quantity up to about 1.0 percent by weight. 
     
     
         9 . The aluminum alloy of  claim 1  further comprising titanium in a non-zero quantity up to about 0.15 percent by weight. 
     
     
         10 . The aluminum alloy of  claim 1  further comprising silver in a non-zero quantity up to about 0.7 percent by weight. 
     
     
         11 . The aluminum alloy of  claim 1  further comprising zirconium in a non-zero quantity up to about 0.16 percent by weight. 
     
     
         12 . The aluminum alloy of  claim 1  further comprising at least one of nickel up to about 0.05 percent by weight, gallium up to about 0.05 percent by weight and vanadium up to about 0.05 percent by weight. 
     
     
         13 . The aluminum alloy of  claim 1  further comprising:
 magnesium in a non-zero quantity up to about 1.9 percent by weight; 
 zirconium in a non-zero quantity up to about 0.16 percent by weight; and 
 silver in a non-zero quantity up to about 0.7 percent by weight. 
 
     
     
         14 . The aluminum alloy of  claim 1  comprising said strontium. 
     
     
         15 . The aluminum alloy of  claim 1  comprising said lanthanum. 
     
     
         16 . The aluminum alloy of  claim 1  comprising said cerium. 
     
     
         17 . The aluminum alloy of  claim 1  comprising said praseodymium. 
     
     
         18 . The aluminum alloy of  claim 1  further comprising:
 magnesium in a non-zero quantity up to about 1.9 percent by weight; 
 zirconium in a non-zero quantity up to about 0.16 percent by weight; 
 silver in a non-zero quantity up to about 0.7 percent by weight; 
 manganese in a non-zero quantity up to about 0.6 percent by weight; 
 zinc in a non-zero quantity up to about 1.0 percent by weight; and 
 titanium in a non-zero quantity up to about 0.15 percent by weight. 
 
     
     
         19 . A method for making an aluminum alloy comprising steps of:
 weighing out starting materials to achieve a mass of material having the composition of  claim 1 ;   loading said starting materials into a crucible;   inserting said crucible into a chamber;   evacuating said chamber to a predetermined vacuum level;   melting said starting materials to form a molten mass; and   casting said molten mass into a mold.   
     
     
         20 . The method of  claim 19  wherein said predetermined vacuum level is at most about 0.05 Torr, and wherein said chamber is backfilled with an inert gas. 
     
     
         21 . The method of  claim 19  wherein:
 said molten mass is cast into a mold; 
 said molten mass is cooled to form a solid mass; 
 said solid mass is homogenized and water quenched to yield an ingot; 
 said ingot is scalped and hot rolled; 
 said ingot is at least one of solution treated, cold-rolled and stretched; and 
 said ingot is aged. 
 
     
     
         22 . The method of  claim 21  where said ingot is aged artificially at about 300 to about 320° F. for about 29 to about 35 hours. 
     
     
         23 . The method of  claim 19  wherein said weighing comprises weighing a mischmetal as a source of said at least one of said lanthanum, said strontium, said cerium and said praseodymium.