High strength thermally resistant ductile cast aluminum alloys

Abstract

The invention relates to a high-strength, thermally-resistant, ductile, cast aluminium alloy (Al Si 7 Mg 0.25 Zr wa, or Al Si 7 Mg 0.25 Hf wa) and (Al Si 6 Mg 0.25 Zr wa or Al Si 6 Mg 0.25 Hf wa), comprising Si: 6.5 to 7.5 wt. % and 5.5 to 6.5 wt.-%, Mg: 0.20 to 0.32 wt. %, Zr: 0.03 to 0.50 wt. % and/or Hf: 0.03 to 1.50 wt. %, Ti: 0 to 0.20 wt. %, Fe: <0.20 wt. %, Mn: <0.50 wt. %, Cu: <0.05 wt. %, Zn: <0.07 wt. % and made up to 100 wt. % with Al. The invention relates to the use thereof for workpieces or parts thereof with elevated thermal loading, such as a cylinder head.

1 - 5 . (canceled)  
   
   
       6 . A cast aluminum alloy comprising 
 Si: 5.5 to 7.5 wt %    Mg: 0.20 to 0.32 wt %    Zr: 0.03 to 0.50 wt % and    Hf: 0.03 to 1.50 wt %    Ti: 0 to 0.20 wt %    Fe: <0.20 wt %    Mn: <0.50 wt %    Cu: <0.05 wt %    Zn: <0.07 wt %    and Al to make 100 wt %, said alloy containing intermetallic Al 3 Zr and/or Al 3 Hf high temperature phases.    
   
   
       7 . A cast aluminum alloy according to  claim 6 , wherein Zr and Hf exist in a mixture in the mentioned regions.  
   
   
       8 . A cast aluminum alloy according to  claim 6 , wherein the alloy contains Al 3 (Zr, Ti) and/or Al 3 (Hf, Ti) phases.  
   
   
       9 . An internal combustion engine including a component made of a cast aluminum alloy.  
   
   
       10 . An internal combustion engine according to  claim 9 , wherein said component is selected from the group consisting of pistons, cylinder heads, crank cases and engine blocs, and parts thereof.