Magnesium alloy sheet and method for producing same

Abstract

The present invention relates to a magnesium alloy sheet and a manufacturing method thereof. An embodiment of the present invention provides a magnesium alloy sheet including 0.5 to 1.5 wt % of Al, 0.5 to 1.5 wt % of Zn, 0.1 to 1.0 wt % of Ca, 0.01 to 1.0 wt % of Mn, a remainder of Mg, and other inevitable impurities with respect to the entire 100 wt % of the magnesium alloy sheet.

What is claimed is: 
     
         1 . A magnesium alloy sheet comprising:
 0.5 to 1.5 wt % of Al, 0.1 to 0.7 wt % of Zn, 0.1 to 0.5 wt % of Ca, 0.01 to 0.3 wt % of Mn, a remainder of Mg, and other inevitable impurities with respect to the entire 100 wt % of the magnesium alloy sheet.   
     
     
         2 . The magnesium alloy sheet of  claim 1 , wherein
 the Al is 0.5 to 1.3 wt % for the entire 100 wt % of the magnesium alloy sheet.   
     
     
         3 . The magnesium alloy sheet of  claim 2 , wherein
 the magnesium alloy sheet includes a secondary phase, and   an area fraction of a secondary phase is equal to or less than 5% for the entire area of 100% of the magnesium alloy sheet.   
     
     
         4 . The magnesium alloy sheet of  claim 3 , wherein
 the secondary phase is Al 2 Ca, Al 8 Mn 5 , or a combination thereof.   
     
     
         5 . The magnesium alloy sheet of  claim 4 , wherein
 the magnesium alloy sheet includes a stringer, and   a length of the stringer is equal to or less than 50 μm at a maximum.   
     
     
         6 . The magnesium alloy sheet of  claim 5 , wherein
 a limited bending radius (LBR) value in a rolling direction (RD) is 0 to 0.5 R/t when the magnesium alloy sheet is at equal to or greater than 150° C.   
     
     
         7 . The magnesium alloy sheet of  claim 6 , wherein
 the limited bending radius (LBR) value in a transverse direction (TD) is 0 to 0.5 R/t when the magnesium alloy sheet is at equal to or greater than 150° C.   
     
     
         8 . The magnesium alloy sheet of  claim 7 , wherein
 a ratio of the limited bending radius (LBR) value in a transverse direction (TD) against the rolling direction (RD) is 0.8 to 1.2 when the magnesium alloy sheet is at equal to or greater than 150° C.   
     
     
         9 . The magnesium alloy sheet of  claim 8 , wherein
 a limited dome height (LDH) of the magnesium alloy sheet is equal to or greater than 8 mm.   
     
     
         10 . A method for manufacturing a magnesium alloy sheet, comprising:
 preparing an alloy molten metal including 0.5 to 1.5 wt % of Al 0.5 to 1.5 wt % of Zn, 0.1 to 1.0 wt % of Ca, 0.01 to 1.0 wt % of Mn, a remainder of Mg, and other inevitable impurities with respect to the entire 100 wt %;   preparing a casting material by casting the molten metal;   preparing a rolled material by rolling the casting material; and   finally annealing the rolled material.   
     
     
         11 . The method of  claim 10 , wherein
 regarding the preparing of an alloy molten metal,   Al is 0.5 to 1.3 wt % for the entire 100 wt % of the alloy molten metal.   
     
     
         12 . The method of  claim 10 , wherein
 the preparing of a rolled material by rolling a casting material includes   performing rolling with a reduction ratio that is equal to or less than 50% (excluding 0%) for each rolling.   
     
     
         13 . The method of  claim 12 , wherein
 the preparing of a rolled material by rolling a casting material includes   rolling the casting material once or at least twice.   
     
     
         14 . The method of  claim 13 , wherein
 the preparing of a rolled material by rolling a casting material includes   performing rolling at a temperature of 100 to 350° C.   
     
     
         15 . The method of  claim 10 , wherein
 the preparing of a rolled material by rolling a casting material further includes   intermediately annealing the rolled material.   
     
     
         16 . The method of  claim 15 , wherein
 the intermediately annealing of the rolled material is performed at a temperature of 300 to 500° C.   
     
     
         17 . The method of  claim 16 , wherein
 the intermediately annealing of the rolled material is performed for 30 minutes to 6 hours.   
     
     
         18 . The method of  claim 10 , wherein
 the finally annealing of the rolled material is performed at equal to or greater than 250° C.   
     
     
         19 . The method of  claim 18 , wherein
 the finally annealing of the rolled material is performed for 30 minutes to 6 hours.   
     
     
         20 . The method of  claim 10 , wherein
 the preparing of a casting material by casting the molten metal includes performing casting by a strip casting method.