Die casting of wrought aluminum alloys

Abstract

A method of making a wrought aluminum alloy component comprises die casting the wrought aluminum alloy in a die cavity to produce a die cast component and isostatically pressing the die cast component to promote closure of internal voids therein.

I claim:  
     
         1 . A method of making a wrought aluminum alloy component, comprising die casting the wrought aluminum alloy in a die cavity at subambient pressure to produce a die cast component with an exterior surface that permits isostatic pressing of said die cast component and isostatically pressing the die cast component to promote closure of internal voids therein.  
     
     
         2 . The method of  claim 1  wherein said alloy is die cast to produce said die cast component that includes an exterior surface substantially free of voids that extend from an interior of said die cast component.  
     
     
         3 . The method of  claim 1  wherein said alloy is die cast with a combination of conditions including a subambient pressure in said die cavity of about 15 to about 50 microns, injection speed greater than about 30 inches/second, and an intensification pressure in the range of about 5,000 to about 20,000 psi on the wrought aluminum alloy after it is injected into the die cavity.  
     
     
         4 . The method of  claim 3  including heating dies defining said die cavity in the range of about 200 to about 400 degrees F.  
     
     
         5 . The method of  claim 1  wherein said die cast component is hot isostatically pressed in a gaseous atmosphere.  
     
     
         6 . The method of  claim 1  including the further step of solution heat treating said die cast component before said isostatic pressing.  
     
     
         7 . The method of  claim 1  including the further step of solution heat treating and aging said die cast component after said isostatic pressing.  
     
     
         9 . The method of  claim 1  wherein said internal voids comprise internal porosity or cracking.  
     
     
         10 . A method of die casting a wrought aluminum alloy component, comprising die casting the wrought aluminum alloy in a die cavity at subambient pressure in said die cavity of about 15 to about 50 microns, injection speed greater than about 30 inches/second, and an intensification pressure in the range of about 5,000 to about 20,000 psi on the wrought aluminum alloy after it is injected into the die cavity.  
     
     
         11 . The method of  claim 10  including heating dies defining said die cavity in the range of about 200 to about 400 degrees F.