A magnesium alloy that has excellent ignition resistance and is excellent in both strength and ductility. The magnesium alloy includes, by weight, 1.0% or greater but less than 7.0% of Al, 0.05% to 2.0% of Ca, 0.05% to 2.0% of Y, greater than 0% but not greater than 6.0% of Zn, and the balance of Mg, and the other unavoidable impurities. The total content of the Ca and the Y is equal to or greater than 0.1 % but less than 2.5% of the total weight of the magnesium alloy. The Mg alloy forms a dense composite oxide layer that acts as a protective film. Thus the Mg alloy has very excellent oxidation resistance and ignition resistance, can be melted, cast and machined in the air or a common inert atmosphere (Ar or N 2 ), and can reduce the spontaneous ignition of chips that are accumulated during the process of machining.
展开▼
