Magnesium alloy sheet and manufacturing method thereof

1. A magnesium alloy sheet comprising 1.0 to 10.5 wt % of Al, 0.1 to 2.0 wt % of Zn, 0.1 to 2.0 wt % of Ca, 0.03 to 1.0 wt % of Y, 0.004 to 0.02 wt % of Be, and a balance of Mg and inevitable impurities, with respect to a total of 100 wt % thereof.

2. The magnesium alloy sheet of claim 1 , wherein

the magnesium alloy sheet satisfies Relational Expression 1:

2[Y]≤[Ca]  Relational Expression 1

wherein the [Y] and [Ca] indicate wt % of each component.

3. The magnesium alloy sheet of claim 2 , wherein

the magnesium alloy sheet satisfies Relational Expression 2:

[Ca]+[Y]≤2.5 wt %  Relational Expression 2

wherein the [Y] and [Ca] indicate wt % of each component.

4. The magnesium alloy sheet of claim 3 , further comprising

0.5 wt % or less of Mn (excluding 0 wt %) with respect to the total of 100 wt % of the magnesium alloy sheet.

5. The magnesium alloy sheet of claim 4 , further comprising

0.004 to 0.01 wt % of Be with respect to the total of 100 wt % of the magnesium alloy sheet.

6. The magnesium alloy sheet of claim 5 , wherein

the other inevitable impurities may be 0.005 wt % or less of Fe, 0.01 wt % or less of Si, 0.01 wt % or less of Cu, 0.01 wt % or less of Ni, or a combination thereof.

7. A manufacturing method of a magnesium alloy sheet, the method comprising:

preparing a casting material containing 1.0 to 10.5 wt % of Al, 0.1 to 2.0 wt % of Zn, 0.1 to 2.0 wt % of Ca, 0.03 to 1.0 wt % of Y, 0.004 to 0.02 wt % of Be, and a balance of Mg and inevitable impurities, with respect to 100 wt % thereof;

homogenizing heat treatment the casting material; and

rolling the homogenized heat-treated casting material to manufacture the magnesium alloy sheet.

8. The manufacturing method of claim 7 , wherein

the casting material satisfies Relational Expression 1 in the preparing of the casting material containing 1.0 to 10.5 wt % of Al, 0.1 to 2.0 wt % of Zn, 0.1 to 2.0 wt % of Ca, 0.03 to 1.0 wt % of Y, 0.002 to 0.02 wt % of Be, and a balance of Mg and inevitable impurities, with respect to the total of 100 wt % thereof:

2[Y]≤[Ca]  Relational Expression 1

wherein the [Y] and [Ca] indicate wt % of each component.

9. The manufacturing method of claim 8 , wherein

the casting material satisfies Relational Expression 2 in the preparing of the casting material containing 1.0 to 10.5 wt % of Al, 0.1 to 2.0 wt % of Zn, 0.1 to 2.0 wt % of Ca, 0.03 to 1.0 wt % of Y, 0.002 to 0.02 wt % of Be, and a balance of Mg and inevitable impurities, with respect to a total of 100 wt % thereof:

[Ca]+[Y]≤2.5 wt %  Relational Expression 2

wherein the [Y] and [Ca] indicate wt % of each component.

10. The manufacturing method of claim 9 , further comprising

0.5 wt % or less of Mn (excluding 0 wt %) with respect to a total of 100 wt % of the casting material in the preparing of the casting material containing 1.0 to 10.5 wt % of Al, 0.1 to 2.0 wt % of Zn, 0.1 to 2.0 wt % of Ca, 0.03 to 1.0 wt % of Y, 0.002 to 0.02 wt % of Be, and a balance of Mg and inevitable impurities, with respect to a total of 100 wt % thereof.

11. The manufacturing method of claim 7 , wherein

in the homogenizing heat treatment of the casting material,

the homogenizing heat treatment is performed in a temperature range of 350 to 500° C.

12. The manufacturing method of claim 7 , wherein

in the soaking of the casting material,

the homogenizing heat treatment is performed for 4 to 48 hours.

13. The manufacturing method of claim 12 , wherein

the rolling of the homogenized heat-treated casting material to manufacture the magnesium alloy sheet includes:

forming a rolled material by rolling the homogenized heat-treated casting material; and

manufacturing the magnesium alloy sheet by buffing the rolled material.