Patent ID: 8246763

Claim:
A hypoeutectic Al—Si alloy casting with low casting defects obtained by casting an aluminum alloy comprised of 9.5 to 11.5 wt % of Si, 3.8 to 4.8 wt % of Cu, 0.45 to 0.65 wt % of Mg, 0.4 to 0.7 wt % of Fe, 0.35 to 0.45 wt % of Mn, and the balance of Al and not more than 0.2 wt % of unavoidable impurities, wherein the hypoeutectic Al—Si alloy contains 0.1 to 1.0 wt % of at least one element selected from the group of second additive elements consisting of Rb, K, Ba, Sr, Zr, Nb, Ta, V, and Pd and at least one element selected from the group of rare earth elements consisting of La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y both added intentionally in order to inhibit casting defects which are attributed to molten hydrogen gas in the alloy casting.