Die cast magnesium alloy

Abstract

A magnesium based alloy contains zinc, aluminium, calcium and/or beryllium, optionally manganese, and the balance magnesium except for incidental impurities. The zinc and aluminium contents fall within a quadrangle defined by lines AB, BC, CD and DA and the calcium and beryllium contents fall within a quadrangle defined by lines EF, FG, GH and HE wherein: A is 10% Zn-2.5% Al, B is 10% Zn-5% Al, C is 13% Zn-6.4% Al, D is 19% Zn-2.5 % Al, E is 0.01% Ca-0% Be, F is 1% Ca-0% Be, G is 0% Ca-0.0025% Be, and H is 0% Ca-0.0001% Be.

1 . An alloy consisting of zinc (Zn) and aluminum (Al) in amounts which fall within a quadrangle defined by lines AB, BC, CD, and DA wherein: 
 A is 10% Zn-2.5% Al,    B is 10% Zn-5% Al,    C is 13% Zn-6.4% Al, and    D is 19% Zn-2.5% Al; 
 calcium (Ca) and/or beryllium (Be) in amounts which fall within a quadrangle defined by lines EF, FG, GH and HE wherein:  
   E is 0.01% Ca-0% Be,    F is 1% Ca-0% Be,    G is 0% Ca-0.0025% Be, and    H is 0% Ca-0.0001% Be 
 optionally manganese; and  
   the balance magnesium except for incidental impurities.    
   
   
       2 . An alloy as claimed in  claim 1  containing greater than 11% zinc.  
   
   
       3 . An alloy as claimed in  claim 2  containing 12-14% zinc.  
   
   
       4 . An alloy as claimed in  claim 1  containing 2.5-5% aluminum.  
   
   
       5 . An alloy as claimed in  claim 4  containing 3-4.5% aluminum.  
   
   
       6 . An alloy as claimed in  claim 1  containing 0.01-0.5% calcium.  
   
   
       7 . An alloy as claimed in  claim 6  containing 0.05-0.2% calcium.  
   
   
       8 . An alloy as claimed in  claim 1  containing 0.0002-0.002% beryllium.  
   
   
       9 . An alloy as claimed in  claim 8  containing 0.0005-0.001% beryllium.  
   
   
       10 . An alloy as claimed in  claim 1  containing manganese in an amount less than 1%.  
   
   
       11 . An alloy as claimed in  claim 10  containing 0.1-0.5% manganese.  
   
   
       12 . A magnesium based alloy consisting of: 
 11-13.5% zinc,    3-4.5% aluminum,    0.05-0.15% calcium,    0.0005-0.001% beryllium, 
 optionally manganese in an amount less than 0.5%, and the balance being magnesium except for incidental impurities.  
   
   
   
       13 . A magnesium based alloy consisting of: 
 11.5-13.5% zinc,    3-4.5% aluminum,    optionally manganese in an amount less than 0.5%,    either 0.05-0.15% calcium,    or 0.0005-0.001% beryllium, and    the balance being magnesium except for the incidental impurities.    
   
   
       14 . A magnesium based alloy consisting of: 
 11.5-13.5% zinc,    3-4.5% aluminum,    0.2-0.4% manganese,    0.05-0.15% calcium,    0.0005-0.001% beryllium, and    the balance being magnesium except for incidental impurities.    
   
   
       15 . A magnesium based alloy consisting of: 
 11.5-13.5% zinc,    3-4.5% aluminum,    0.2-0.4% manganese,    either 0.05-0.15% calcium,    or 0.0005-0.001% beryllium, and    the balance being magnesium except for incidental impurities.    
   
   
       16 . An alloy as claimed in  claim 12  containing 12-13% zinc, 3.5-4% aluminum, less than 0.08% silicon, less than 40 ppm iron, and less than 10 ppm nickel.