The invention discloses a Zn-containing medium-strength high-
ductility die-cast aluminum
alloy and a preparation method thereof, and belongs to the field of
metal materials. The invention provides a
casting aluminum
alloy material which is medium in strength, is high in
ductility, is free of
thermal treatment and is suitable for die-cast formation as well as a preparation method thereof. The medium-strength high-
ductility die-cast aluminum
alloy consists of the following chemical components in percentage by weight: 10.0-13.0% of Si, 4.1-7.1% of Zn, 0.5-0.8% of Fe, 0.1-0.4% of Mn, 0.02-0.04% ofSr, less than or equal to 0.01% of Mg, less than or equal to 0.01% of Cu, less than or equal to 0.15% of other
impurity elements, and the balance of Al. The preparation method comprises the followingsteps:
smelting, sampling to rest, regulating alloy components, adding intermediate alloy to refine, de-slagging and
casting. Through thermodynamic calculation, content range of Si, Fe and Mn of
ternary eutectic Al-Si-Al(FeMn)Si is determined to reduce adverse effects, on alloy
plasticity, of Mn and Fe; and Sr is the most common and effective eutectic
silicon modifier, so that eutectic
silicon ispromoted to convert to fine fibers from thick faller gills, and therefore, alloy
plasticity is further improved.