High-thermal-conductivity and high-toughness die-casting aluminum-silicon alloy and preparation method thereof

The invention discloses a high-thermal-conductivity and high-toughness die-casting aluminum-silicon alloy and a preparation method thereof. The high-thermal-conductivity and high-toughness die-casting aluminum-silicon alloy is prepared from the following components in percentage by mass: 11-13wt% of Si, 0.15-0.5wt% of Fe, 0.2-0.65wt% of Co, 0.02-0.08wt% of Sr, 0.03-0.1wt% of B, 0.01-0.18wt% of La, 0.05-0.5wt% of Zn, less than 0.15% of inevitable impurities and the balance of Al, wherein the mass ratio of Co to Fe is (0.9-1.2) to 1. For the high-thermal-conductivity and high-toughness die-casting aluminum-silicon alloy and the preparation method disclosed by the invention, by adding the Si as an alloy element and auxiliarily adding a trace amount of elements including the Fe, the Co and the Zn, the aluminum-silicon alloy has a relatively narrow solidification interval, a melt has excellent fluidity, the toughness of the aluminum-silicon alloy is remarkably improved, and thus the prepared aluminum-silicon alloy