High corrosion resistance aluminum alloy for sand and permanent mold processes

Abstract

An aluminum-based casting alloy having improved corrosion resistance and casting characteristics for sand and permanent mold casting processes. The aluminum-based casting alloy contains from about 4.0 to about 7.0 percent silicon by weight, at least 87 percent aluminum by weight, from about 0.25 percent to about 0.5 percent manganese by weight, a maximum of 0.08 percent copper by weight, and from about 0.2 percent to about 0.8 percent iron by weight.

1 . An aluminum-based alloy comprising:
 at least about 87 percent aluminum by weight;   from about 4.0 percent to about 8.5 percent silicon by weight;   from about 0.25 percent to about 0.5 percent manganese by weight;   a maximum of about 0.08 percent copper by weight; and   from about 0.2 percent to about 0.8 percent iron by weight.   
     
     
         2 . The alloy of  claim 2 , wherein the silicon is present in an amount of from about 4.0 to 7.0 percent by weight. 
     
     
         3 . The alloy of  claim 1 , having a maximum of 0.05 percent copper by weight. 
     
     
         4 . The alloy of  claim 1 , wherein the aluminum is present in the alloy in an amount of at least 88 percent by weight. 
     
     
         5 . The alloy of  claim 1 , wherein the aluminum is present in the alloy in an amount of at least 89 percent by weight. 
     
     
         6 . The alloy of  claim 1 , wherein the manganese is present in an amount of from about 0.3 percent to about 0.5 percent by weight. 
     
     
         7 . An article of manufacture made from an aluminum alloy comprising:
 at least about 87 percent aluminum by weight;   from about 4.0 percent to about 8.5 percent silicon by weight;
 from about 0.25 percent to about 0.5 percent manganese by weight; 
   a maximum of about 0.08 percent copper by weight; and   from about 0.2 percent to about 0.8 percent iron by weight.