Calcium-bearing magnesium and rare earth element alloy and method for manufacturing the same

Abstract

A calcium-bearing magnesium and rare earth element alloy consists essentially of, in mass percent, zinc (Zn): 1-3%; aluminum (Al): 1-3%; calcium (Ca): 0.1-0.4%; gadolinium (Gd): 0.1-0.4%; yttrium (Y): 0-0.4%; manganese (Mn): 0-0.2%; and balance magnesium (Mg).

What is claimed is: 
     
         1 . A magnesium alloy consisting essentially of:
 about 1 to about 3 percent by weight zinc;   about 1 to about 3 percent by weight aluminum;   about 0.1 to about 0.4 percent by weight calcium;   about 0.1 to about 0.4 percent by weight gadolinium;   zero to about 0.4 percent by weight yttrium;   zero to about 0.2 percent by weight manganese; and   balance magnesium.   
     
     
         2 . The magnesium alloy of  claim 1  wherein the yttrium is present at a non-zero quantity. 
     
     
         3 . The magnesium alloy of  claim 1  wherein the manganese is present at a non-zero quantity. 
     
     
         4 . The magnesium alloy of  claim 1  wherein the yttrium is present at a non-zero quantity and the manganese is present at a non-zero quantity. 
     
     
         5 . The magnesium alloy of  claim 1  wherein the zinc is present at about 1 to about 2 percent by weight. 
     
     
         6 . The magnesium alloy of  claim 1  wherein the aluminum is present at about 1 to about 2 percent by weight. 
     
     
         7 . The magnesium alloy of  claim 1  wherein the calcium is present at about 0.1 to about 0.2 percent by weight. 
     
     
         8 . The magnesium alloy of  claim 1  wherein the gadolinium is present at about 0.1 to about 0.2 percent by weight. 
     
     
         9 . The magnesium alloy of  claim 1  wherein the yttrium is present at about 0 to about 0.2 percent by weight. 
     
     
         10 . The magnesium alloy of  claim 1  wherein the manganese is present at about 0 to about 0.2 percent by weight. 
     
     
         11 . The magnesium alloy of  claim 1  wherein:
 the zinc is present at about 1 to about 2 percent by weight; 
 the aluminum is present at about 1 to about 2 percent by weight; 
 the calcium is present at about 0.1 to about 0.2 percent by weight; 
 the gadolinium is present at about 0.1 to about 0.2 percent by weight; 
 the yttrium is present at about 0 to about 0.2 percent by weight; and 
 the manganese is present at about 0 to about 0.2 percent by weight. 
 
     
     
         12 . The magnesium alloy of  claim 1  in a form of a sheet. 
     
     
         13 . The magnesium alloy of  claim 12  wherein the sheet is a solution treated sheet. 
     
     
         14 . The magnesium alloy of  claim 13  wherein the sheet is an annealed solution treated sheet. 
     
     
         15 . The magnesium alloy of  claim 14  wherein the sheet has a tensile strength of at least about 245 MPa, an elongation to failure of at least about 18 percent, and an IE value of at least about 4.5. 
     
     
         16 . The magnesium alloy of  claim 14  wherein the sheet has a tensile strength of about 245 to about 280 MPa, an elongation to failure of about 18 to about 32 percent, and an IE value of about 4.5 to about 7.0. 
     
     
         17 . A sheet of magnesium alloy, the magnesium alloy consisting essentially of:
 about 1 to about 3 percent by weight zinc;   about 1 to about 3 percent by weight aluminum;   about 0.1 to about 0.4 percent by weight calcium;   about 0.1 to about 0.4 percent by weight gadolinium;   zero to about 0.4 percent by weight yttrium;   zero to about 0.2 percent by weight manganese; and   balance magnesium.   
     
     
         18 . An alloy sheet formed by a method comprising:
 weighting raw materials to yield a magnesium alloy composition consisting essentially of:
 about 1 to about 3 percent by weight zinc; 
 about 1 to about 3 percent by weight aluminum; 
 about 0.1 to about 0.4 percent by weight calcium; 
 about 0.1 to about 0.4 percent by weight gadolinium; 
 zero to about 0.4 percent by weight yttrium; 
 zero to about 0.2 percent by weight manganese; and 
 balance magnesium; 
   charging the raw materials into a vacuum induction melting furnace to obtain a molten mass;   casting the molten mass to yield a magnesium alloy ingot;   solid solution treating the magnesium alloy ingot to yield a treated magnesium alloy ingot;   hot rolling the treated magnesium alloy ingot to yield a rolled material;   cutting defects from the rolled material to obtain an alloy sheet; and   annealing the alloy sheet.   
     
     
         19 . The alloy sheet of  claim 18  having a tensile strength of at least about 245 MPa, an elongation to failure of at least about 18 percent, and an IE value of at least about 4.5. 
     
     
         20 . The alloy sheet of  claim 18  wherein the sheet has a tensile strength of about 245 to about 280 MPa, an elongation to failure of about 18 to about 32 percent, and an IE value of about 4.5 to about 7.0.