Patent ID: 8292589

Claim:
A cast compressor impeller formed from a casting aluminum alloy, comprising a hub shaft part, a hub disk part extending radially from the hub shaft part and having a hub surface and a disk surface, and a plurality of blade parts provided on the hub surface, wherein the casting aluminum alloy comprises, by mass %, 3.5 to 5.0% Cu, 0.8 to 3.0% Ni, 1.0 to 3.0% Mg, 0.05 to 0.20% Ti, and not more than 1.0% Si, and the balance being Al and unavoidable impurities, and wherein the impeller has a tensile strength of at least 380 MPa and an elongation of at least 5.0% at ordinary temperature (25° C.), a tensile strength of at least 330 MPa at a temperature of 150° C., and a tensile strength of at least 300 MPa at a temperature of 200° C.