Patent 11149330 was granted and assigned to POSCO E&C on October, 2021 by the United States Patent and Trademark Office.
According to an exemplary embodiment of the present invention, a manufacturing method of a magnesium alloy plate includes: (a) solution-treating a magnesium casting material containing 0.5 to 10 wt % of zinc (Zn), 1 to 15 wt % of aluminum (Al), and a balance of magnesium (Mg) and inevitable impurities at 300 to 500° C. for 1 to 48 hours; (b) pre-heating the solution-treated magnesium casting material at 300 to 500° C.; and (c) of rolling the pre-heated magnesium casting material together with a constraint member selected by following Relational Expression 1 to satisfy Relational Expressions 2 and 3; and (d) solution-treating a thus-rolled magnesium alloy plate at 300 to 500° C. for 0.5 to 5 hours. Relational Expressions 1 to 3 are as described in the specification.