Patent ID: 7682469

Claim:
A piston made of an aluminum cast alloy, wherein the aluminum cast alloy has a hypereutectic structure and comprises: Mg (Magnesium): 0.2-2 mass %, Ti (Titanium): 0.15-0.3 mass %, Si (Silicon): 10-21 mass %, Cu (Copper): 2-3.5 mass %, Fe (Iron): 0.1-0.7 mass %, Ni (Nickel): 1-3 mass %, P (Phosphorus): 0.001-0.02 mass %, V (Vanadium): 0.02-0.3 mass %, Zr (Zirconium): 0.02-0.3 mass %, Mn (Manganese): 0.2-0.7 mass %, Ca (Calcium): 0.0005-0.003 mass %, Al (Aluminum): the remaining portions, and impurities, and wherein pre-use Vickers hardness (Vickers hardness prior to the initiation of use) of the piston is in the range from HV 70 to 100.