MAGNESIUM ALLOY SHEET AND METHOD FOR PRODUCING SAME

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.