Oxidation resistant al-mg high strength die casting foundry alloys

Abstract

The present disclosure concerns a foundry alloy suitable for casting operations which lack beryllium. The foundry alloy comprises, in weight percent, Mg (between about 1.0 and about 17.0), Fe (between about 0.5 and about 1.8), one of Ca (between about 0.003 and about 6.0) or Sr (between about 0.003 and about 2.5), optionally a grain refiner and the balance being aluminum and unavoidable impurities. The foundry alloy can be used in a process for making a cast aluminum product, for reducing Mg loss and/or dross generation during the casting operation.

1 . A foundry alloy comprising, in weight percent:
 Mg between about 1.0 and about 17.0;   Fe between about 0.5 and about 1.8;   one of Ca between about 0.003 and about 6.0 or Sr between about 0.003 and about 2.5; and   the balance being aluminum and unavoidable impurities,   wherein the foundry alloy lacks Be as an alloying element.   
     
     
         2 . The foundry alloy of  claim 1 , further comprising a grain refiner. 
     
     
         3 . (canceled) 
     
     
         4 . The foundry alloy of  claim 1 , comprising between about 0.01 and about 0.3 Ca. 
     
     
         5 . The foundry alloy of  claim 1 , comprising between about 3.0 to about 8.0 Mg, optionally between about 4.0 and about 6.0 Mg. 
     
     
         6 . The foundry alloy of  claim 1 , comprising between about 4.0 and about 6.0 Mg. 
     
     
         7 - 8 . (canceled) 
     
     
         9 . A process for making a cast aluminum product, the process comprising casting the foundry aluminum alloy of  claim 1  in a mold. 
     
     
         10 . The process of  claim 9 , further comprising submitting the cast aluminum alloy to high-pressure vacuum die casting, optionally lacking a post-cast thermal treatment step. 
     
     
         11 - 18 . (canceled) 
     
     
         19 . The process of  claim 9 , wherein the process further compromises limiting Mg loss and dross generation by adding one of Ca between about 0.003 and about 6.0 or Sr between about 0.003 and about 2.5 to a first aluminum alloy to obtain a foundry alloy intended to be cast, the first aluminum alloy comprising, in weight percent:
 Mg between about 1.0 and about 17.0;   Fe between about 0.5 and about 1.8; and   the balance being aluminum and unavoidable impurities,   wherein the first aluminum alloy and the foundry alloy lack Be as an alloying element.   
     
     
         20 . The process of  claim 19 , wherein the first aluminum alloy further comprises a grain refiner. 
     
     
         21 . The process of  claim 19 , further comprising melting the foundry alloy to obtain a molten foundry alloy. 
     
     
         22 . The process of  claim 21 , for reducing Mg loss lower than about 12 weight percent, when the molten foundry alloy is held for a period of at least 6 hours. 
     
     
         23 . The process of  claim 21 , for reducing dross generation lower than about 7 weight percent, when the molten foundry alloy is held for a period of at least 6 hours. 
     
     
         24 . The process of  claim 21 , further comprising casting the molten foundry alloy to obtain a cast aluminum alloy. 
     
     
         25 . The process of  claim 24 , further comprising submitting the cast aluminum alloy to high-pressure vacuum die casting. 
     
     
         26 . The process of  claim 19 , lacking a post-cast heat treatment step. 
     
     
         27 . The process of  claim 19 , wherein the first aluminum alloy comprises Ca. 
     
     
         28 . The process of  claim 27 , wherein the first aluminum alloy comprises between about 0.01 and about 0.3 Ca. 
     
     
         29 . The process of  claim 19 , wherein the first aluminum alloy comprises between about 3.0 and about 8.0 Mg. 
     
     
         30 . The process of  claim 19 , wherein the first aluminum alloy comprises between about 4.0 and about 6.0 Mg. 
     
     
         31 . The process of  claim 19 , wherein the first aluminum alloy comprises between about 0.8 and about 1.8 Fe.