The invention discloses a
magnesium-aluminum
alloy with continuous eutectic structure and a preparation method thereof, and the
alloy is composed of a
magnesium-aluminum
alloy matrix and a continuouseutectic phase distributed at the grain edge of the matrix. The preparation method comprises the following steps that (1) nano-sized
titanium powder and the
magnesium-aluminum alloy
powder are placedin a
ball mill, and ball milling is conducted under protective
atmosphere to obtain the mixed
powder; and (2) the mixed powder is used as a
raw material, and the magnesium-aluminum alloy with the continuous eutectic structure is prepared through
selective laser melting under the protective
atmosphere. According to the preparation method, the
titanium is introduced in the magnesium-aluminum alloy preparation process, aluminum atoms in a
molten pool are attracted to migrate, and eutectic reaction is generated on the edge of the
crystal grain to generate the continuous eutectic phase; meanwhile,the characteristic that the
selective laser melting solidification speed is high is utilized, the formation of the continuous eutectic phase is promoted while the content of a second phase Mg17Al12 isreduced, so that
galvanic corrosion effect of the magnesium aluminum alloy is effectively weakened, and the
corrosion resistance of the magnesium-aluminum alloy is improved; and meanwhile, better interface combination is achieved, so that the
mechanical property of the magnesium-aluminum alloy is improved.