HYPEREUTECTIC AL-SI CASTING ALLOY OF GOOD CASTABILITY AND IMPROVED SALT-WATER CORROSION RESISTANCE

摘要

A hypereutectic aluminum-silicon casting alloy having particular use in casting cylinder blocks for marine engines. The alloy is composed by weight of 16% to 19% of silicon, 0.4 to 0.7% magnesium, up to 0.37% copper and the balance aluminum. With the stated silicon content the alloy has good fluidity and the precipitated silicon crystals provide excellent wear resistance. In addition, the alloy has a narrow solidification range of less than 150 DEG F., thereby providing the alloy with excellent castability. The copper content is maintained at a minimum so that the alloy has improved resistance to salt water corrosion.