Magnesium alloy

Abstract

An improved, castable, magnesium-based alloy having good creep resistance, good corrosion resistance, with improved tensile strength and elongation; methods for preparing the alloys; methods for preparing articles from the alloys; and articles, machines, and other devices comprising the same.

1 . A creep-resistant, castable magnesium alloy comprising, by weight:
 from about 6 to about 7.5% aluminum;   from about 1 to about 3.5% rare earth metals;   from about 0.2 to about 0.45% zinc;   from about 0.15 to about 0.25% manganese;   from about 0.01 to about 0.9% calcium;   from zero to about 0.001% beryllium;   from about 0.01 to about 0.12% tin;   from about 0.01 to about 0.11% strontium;   and the balance being magnesium and, optionally, impurities commonly found in magnesium alloys.   
     
     
         2 . A creep-resistant, castable magnesium alloy comprising, by weight:
 from about 6.5, to about 7.5% aluminum;   from about 1.5 to about 2.5% rare earth metals;   from about 0.35 to about 0.45% zinc;   from about 0.15 to about 0.25% manganese;   from about 0.01 to about 0.1% calcium;   about 0.001% beryllium;   from zero to about 0.01 tin;   from zero to about 0.01% strontium;   and the balance being magnesium and, optionally, impurities commonly found in magnesium alloys.   
     
     
         3 . A creep-resistant, castable magnesium alloy comprising, by weight:
 from about 7 to about 7.2% aluminum;   from about 1.5 to about 1.75% rare earth metals;   from about 0.35 to about 0.4% zinc;   from about 0.15 to about 0.2% manganese;   from about 0.01 to about 0.02% calcium;   form about 0.0005 to about 0.001% beryllium;   about 0.01% tin;   and the balance being magnesium and, optionally, impurities commonly found in magnesium alloys.   
     
     
         4 . The allay according to  claim 3 , wherein the alloy comprises, by weight:
 about 7.18% aluminum;   about 1.62% rare earth metals;   about 0.355% zinc;   about 0.17% manganese;   about 0.01% calcium;   about 0.0007% beryllium;   about 0.01% tin;   and the remainder magnesium and, optionally, impurities commonly found in magnesium alloys.   
     
     
         5 . The alloy according to  claim 1 , wherein the alloy comprises from about 6.5 to about 7.5% by weight aluminum. 
     
     
         6 . The alloy according to  claim 5 , wherein the alloy comprises from about 7 to about 7.5% by weight aluminum. 
     
     
         7 . The alloy according to  claim 1 , wherein the alloy comprises from about 0.35 to about 0.45%: by weight zinc. 
     
     
         8 . The alloy according to  claim 7 , wherein the alloy comprises from about 0.35 to about 0.4% by weight zinc. 
     
     
         9 . The alloy according to  claim 1 , wherein the alloy exhibits an ultimate tensile strength of about or at least 39 ksi, as measured according to ASTM B-557. 
     
     
         10 . The alloy according to  claim 1 , wherein the alloy exhibits a percent elongation at break of more than 13% as measured according to ASTM D-1708.