High performance automobile body casting aluminum and its preparation method

The present invention relates to a method for preparing aluminum alloys and die casting, aluminum die-casting of the weight percent composition of: Si9.5% ~ 11.5%, Mn0.3% ~ 0.6%, Mg0.1% ~ 0.6%, Ti0.1 % ~ 0.2%, Sr0.01% ~ 0.02%, B0.02% ~ 0.04%, Fe & lt; 0.25%, the rest is Al. Feed resistance furnace crucible formulated, respectively Al-5Ti-B, Al-10Sr master alloy in the form of adding Ti, B and Sr smelting the aluminum alloy melt, to prevent Ti, B and Sr burning. Pouring temperature 680 ℃, 4.0m / s Fast Shot under the process conditions, the prepared aluminum die-cast tensile strength greater than 225MPa, elongation greater than 6%. Casting aluminum alloy material according to the present invention, not only good fluidity, suitable for filling large thin-walled member, and the die casting is cast of a high tensile strength and ductility, to meet the requirements of the automotive body structure.