High temperature cast aluminum-copper-manganese-zirconium alloys with low temperature ductility

Abstract

Disclosed herein are embodiments of an Al—Cu—Mn—Zr alloy for use with casting processes. The disclosed alloy embodiments provide fabricated objects, such as cast engine components comprising a heterogeneous microstructure and having good castability, resistance to hot tearing, and high ductility at room temperature. Methods for making and using alloy embodiments also are disclosed herein.

We claim: 
     
         1 . An alloy comprising:
 7 wt % to 10 wt % copper;   greater than 0.3 wt % to 0.5 wt % zirconium;   0.05 wt % to 1 wt % manganese;   greater than 0 wt % to 0.1 wt % silicon; and   aluminum.   
     
     
         2 . The alloy of  claim 1 , wherein the alloy is a cast alloy and has a microstructure comprising an aluminum matrix phase and an intermetallic phase comprising copper and aluminum. 
     
     
         3 . The alloy of  claim 2 , wherein the intermetallic phase has a rounded geometry. 
     
     
         4 . The alloy of  claim 2 , wherein the intermetallic phase further comprises zirconium. 
     
     
         5 . The alloy of  claim 2 , wherein the aluminum matrix phase further comprises a plurality of grain boundaries between aluminum matrix grains and the intermetallic phase is partially distributed along the plurality of grain boundaries and partially distributed within the volume of the aluminum matrix grains. 
     
     
         6 . The alloy of  claim 1 , wherein the alloy further comprises one or more elements selected from nickel, cobalt, titanium, boron, iron, magnesium, or antimony. 
     
     
         7 . The alloy of  claim 6 , wherein the titanium is present in the alloy in an amount ranging from greater than 0.0 wt % to 0.3 wt % and the boron is present in the alloy in an amount ranging from greater than 0 wt % to less than 0.07 wt %. 
     
     
         8 . The alloy of  claim 1 , wherein the alloy comprises 7.5 wt % copper, greater than 0.3 wt % to 0.4 wt % zirconium, 0.15 wt % Mn, less than 0.05 wt % silicon, and a balance of aluminum. 
     
     
         9 . The alloy of  claim 1 , wherein the alloy comprises greater than 0.3 wt % zirconium to less than 0.5 wt % zirconium. 
     
     
         10 . The alloy of  claim 1 , wherein the alloy further comprises one or more grain refiners. 
     
     
         11 . The alloy of  claim 10 , wherein the one or more grain refiners includes a TiBor master alloy, titanium boride, titanium carbide, or a combination thereof. 
     
     
         12 . The alloy of  claim 1 , wherein the alloy has a total tensile ductility of greater than 5%. 
     
     
         13 . The alloy of  claim 1 , wherein the alloy comprises 7.35 wt % copper, 0.14 wt % manganese, 0.4 wt % zirconium, less than 0.1 wt % silicon, minor impurities, and a balance of aluminum. 
     
     
         14 . A component fabricated from the alloy of  claim 1 . 
     
     
         15 . The component of  claim 14 , wherein the component is an engine component. 
     
     
         16 . A method for making an alloy, comprising:
 combining 7 wt % to 10 wt % copper; greater than 0.3 wt % to 0.5 wt % zirconium; 0.05 wt % to 1 wt % manganese; greater than 0 wt % to 0.1 wt % silicon; and aluminum to form a composition;   melting the composition; and   solidifying the composition to form the alloy.   
     
     
         17 . The method of  claim 16 , wherein solidifying the composition to form the alloy is accomplished by sand casting, die casting, investment casting, or pressure-assisted die casting. 
     
     
         18 . The method of  claim 16 , wherein the method further comprises adding one or more grain refiners to the composition. 
     
     
         19 . The method of  claim 16 , wherein the zirconium is present in an amount ranging from greater than 0.3 wt % to less than 0.45 wt % 
     
     
         20 . The method of  claim 18 , wherein the method further comprising pouring the alloy into a mold no more than 5 minutes after the one or more grain refiners have been added to the composition.