Magnesium alloys with improved castability, and cast parts made with such alloys

Abstract

Magnesium alloys are disclosed for diecasting with reduced defects comprising aluminum in an amount greater than or equal to about 10 wt % and less than and equal to about 15 wt %; zinc in an amount greater than 0 and less than or equal to about 0.5 wt %; silicon in an amount greater than 0 and less than or equal to about 1.5 wt %; and the balance being magnesium and unavoidable impurities. Magnesium parts diecast from these magnesium alloys are also disclosed.

What is claimed is: 
     
         1 . A magnesium alloy for diecasting with reduced defects, the alloy comprising:
 aluminum in an amount greater than or equal to about 10 wt % and less than and equal to about 15 wt %   zinc in amount greater than 0 and less than or equal to about 0.5 wt %;   silicon in an amount greater than 0 and less than or equal to about 1.5 wt %;   the balance being magnesium and unavoidable impurities.   
     
     
         2 . The magnesium alloy according to  claim 1  wherein the magnesium alloy comprises aluminum in an amount greater than or equal to about 10 wt % and less than or equal to about 13 wt %. 
     
     
         3 . The magnesium alloy according to  claim 1  wherein the magnesium alloy comprises aluminum in an amount greater than or equal to about 13 wt % and less than or equal to about 15 wt %. 
     
     
         4 . The magnesium alloy according to  claim 1  wherein the magnesium alloy has up to a total of about 0.15 wt % additional elements, each additional element comprising no more than about 0.05 wt %. 
     
     
         5 . The magnesium alloy according to  claim 1  wherein the magnesium alloy has CSI of less than about 250. 
     
     
         6 . The magnesium alloy according to  claim 1  wherein the magnesium alloy comprises zinc in amount of at least about 0.1 wt %. 
     
     
         7 . The magnesium alloy according to  claim 1  wherein the magnesium alloy comprises silicon in an amount less than or equal to about 1.0 wt %. 
     
     
         8 . The magnesium alloy according to  claim 7  wherein the magnesium alloy comprises silicon in an amount greater than or equal to about 0.5 wt %. 
     
     
         9 . A cast magnesium part made by thixomolding the magnesium alloy according to  claim 1 . 
     
     
         10 . The cast magnesium part according to  claim 9 , wherein the magnesium alloy has up to a total of about 0.15 wt % additional elements, each additional element comprising no more than about 0.05 wt %. 
     
     
         11 . The cast magnesium part according to  claim 10  wherein the magnesium alloy has CSI of less than about 250. 
     
     
         12 . The cast magnesium part according to  claim 11  wherein the magnesium alloy comprises zinc in amount of at least about 0.1 wt %. 
     
     
         13 . The cast magnesium part according to  claim 12  wherein the magnesium alloy comprises silicon in an amount less than or equal to about 1.0 wt %. 
     
     
         14 . The cast magnesium part according to  claim 13  wherein the magnesium alloy comprises silicon in an amount greater than or equal to about 0.5 wt %. 
     
     
         15 . A magnesium alloy for diecasting with reduced defects, the alloy comprising:
 aluminum in an amount greater than or equal to about 10 wt % and less than or equal to about 15 wt %;   zinc in an amount greater than or equal to about 0.1 wt % and less than or equal to about 0.5 wt %;   silicon in an amount greater than about 0.5 wt % and less than or equal to about 1.0 wt %; and   the balance being magnesium and unavoidable impurities.   
     
     
         16 . The magnesium alloy according to  claim 15  wherein the magnesium alloy has up to a total of about 0.15 wt % additional elements, each additional element comprising no more than about 0.05 wt %. 
     
     
         17 . The magnesium alloy according to  claim 15  wherein the magnesium alloy has CSI of less than about 250. 
     
     
         18 . The magnesium alloy according to  claim 15  wherein the magnesium alloy comprises aluminum in an amount greater than or equal to about 10 wt % and less than or equal to about 13 wt %. 
     
     
         19 . The magnesium alloy according to  claim 15  wherein the magnesium alloy comprises aluminum in an amount greater than or equal to about 13 wt % and less than or equal to about 15 wt %.