Casting aluminum alloys for high-performance applications

Abstract

In various embodiments, aluminum alloys having yield strengths greater than 120 MPa, and typically in the range from 140 MPa to 175 MPa, are described. Further, such alloys can have electrical conductivity of greater than 45% IACS, typically in the range from 45-55% IACS. In one embodiment, the aluminum alloy comprises Si from 1 to 4.5 wt %, Mg from 0.3 to 0.5 wt %, TiB2 from 0.02 to 0.07 wt %, Fe less than 0.1 wt %, Zn less than 0.01 wt %, Cu less than 0.01 wt %, Mn less than 0.01 wt %, the remaining wt % being Al and incidental impurities. Such alloys can be used to cast a variety of automotive parts, including rotors, stators, busbars, inverters, and other parts.

What is claimed is: 
     
         1 . An alloy comprising:
 Si in the range of 1 to less than 4.0 wt %,   Mg of 0.3 to 0.5 wt %,   Sr in the range of 0.02 to 0.06 wt %,   Fe in the range from 0.1 to 0.3 wt %,   Mn in the range of less than 0.01 wt %, and   the remaining wt % being Al and incidental impurities, and wherein the electrical conductivity of the cast aluminum alloy is at least about 45% IACS.   
     
     
         2 . The alloy of  claim 1 , wherein the alloy comprises about 0.5 wt % Mg. 
     
     
         3 . The alloy of  claim 1 , wherein the alloy comprises about 0.04 wt % Sr. 
     
     
         4 . The alloy of  claim 1 , wherein the alloy comprises from 3.5 to less than 4 wt % Si. 
     
     
         5 . The alloy of  claim 1 , wherein the alloy comprises about 3.5% Si. 
     
     
         6 . The alloy of  claim 1 , wherein the yield strength of the alloy is 120 MPa or greater. 
     
     
         7 . The alloy of  claim 1 , wherein the electrical conductivity of the cast aluminum alloy is about 45-48% IACS. 
     
     
         8 . The alloy of  claim 1 , cast into a rotor. 
     
     
         9 . An article comprising a cast aluminum alloy, wherein the alloy comprises:
 Si in the range of 1 to less than 4.0 wt %,   Mg of 0.3 to 0.5 wt %,   Sr in the range of 0.02 to 0.06 wt %,   Fe in the range from 0.1 to 0.3 wt %,   Mn in the range of less than 0.01 wt %, and   the remaining wt % being Al and incidental impurities, and wherein the electrical conductivity of the cast aluminum alloy is at least about 45% IACS.   
     
     
         10 . The article of  claim 9 , wherein the article is a vehicle part. 
     
     
         11 . The article of  claim 9 , wherein the article is an electric-vehicle part. 
     
     
         12 . The article of  claim 9 , wherein the article is a rotor. 
     
     
         13 . The article of  claim 9 , wherein the alloy comprises about 0.5 wt % Mg. 
     
     
         14 . The article of  claim 9 , wherein the alloy comprises about 0.04% Sr. 
     
     
         15 . The article of  claim 9 , wherein the alloy comprises from 3.5 to less than 4 wt % Si. 
     
     
         16 . The article of  claim 9 , wherein the alloy comprises 3.5 wt % Si. 
     
     
         17 . The article of  claim 9 , wherein the yield strength of the alloy is 120 MPa or greater. 
     
     
         18 . The article of  claim 9 , wherein the electrical conductivity of the cast aluminum alloy is about 45-48% IACS. 
     
     
         19 . A method for producing an aluminum alloy, the method comprising:
 forming a melt that comprises an aluminum alloy, wherein the alloy comprises:
 Si in the range of 1 to less than 4.0 wt %, 
 Mg of 0.3 to 0.5 wt %, 
 Sr in the range of 0.02 to 0.06 wt %, 
 Fe in the range from 0.1 to 0.3 wt %, 
 Mn in the range of less than 0.01 wt %, and 
 the remaining wt % being Al and incidental impurities; and 
   casting the melt according to an as-cast, T5, T6, or T7 process.   
     
     
         20 . The method of  claim 19 , wherein the melt is cast into the form of a rotor. 
     
     
         21 . The method of  claim 20 , wherein the yield strength of the alloy is 120 MPa or greater.