Disclosed is a
magnesium alloy that has high
thermal conductivity and
flame retardancy and facilitates plastic working, wherein
magnesium is added with 0.5 to 5 wt % of
zinc (Zn) and 0.3 to 2.0 wt % of at least one of
yttrium (Y) and
mischmetal, with, as necessary, 1.0 wt % or less of at least one selected from among
calcium (Ca),
silicon (Si),
manganese (Mn) and
tin (Sn), the total amount of
alloy elements being 2.5 to 6 wt %. A method of manufacturing the same is also provided, including preparing a
magnesium-
zinc alloy melt in a
melting furnace, adding high-melting-point elements in the form of a master alloy and melting them, and performing mechanical stirring during cooling of a cast material in a
continuous casting mold containing the
magnesium alloy melt, thus producing a
magnesium alloy cast material having low segregation, after which a chill is removed from the cast material or
diffusion annealing is performed, followed by molding through a
tempering process such as rolling,
extrusion or
forging. This
magnesium alloy is improved in
ductility by the action of alloy elements for inhibiting the formation of lamella precipitates due to a low-melting-point eutectic phase in a magnesium matrix structure, can be extruded even at a pressure of 1,000 kgf / cm2 or less due to the increased
plasticity thereof, and can exhibit
thermal conductivity of 100 W / m·K or more and
flame retardancy satisfying the requirements for aircraft materials and is thus suitable for use in fields requiring
fire safety, thereby realizing wide application thereof as a
heat sink or a
structural material for portable appliances, vehicles and aircraft components and contributing to weight reduction.