Heat-resistant and creep-resistant aluminum alloy and billet thereof, and method for their production

A billet of a heat-resistant, creep-resistant aluminum alloy containing at least 10 mass % and not more than 30 mass % of silicon, at least 3 mass % and not more than 10 mass % of at least either iron or nickel in total, at least 1 mass % and not more than 6 mass % of at least one rare earth element in total and at least 1 mass % and not more than 3 mass % of zirconium while containing none of titanium, magnesium and copper, with the rest substantially containing aluminum,

• having a substantially cylindrical shape.

A method of preparing a heat-resistant, creep-resistant aluminum alloy containing at least 10 mass % and not more than 30 mass % of silicon, at least 3 mass % and not more than 10 mass % of at least either iron or nickel in total, at least 1 mass % and not more than 6 mass % of at least one rare earth element in total and at least 1 mass % and not more than 3 mass % of zirconium with the rest substantially consisting of aluminum,

• comprising a step of molding rapidly cooled alloy powder consisting of an aluminum alloy into a pressurized powder compact (1a) and thereafter working said pressurized powder compact (1a) into a product shape (1c) by hot plastic working, wherein
• the time exposing said pressurized powder compact (1a) not yet worked into said product shape (1c) to a temperature of at least 450° C. is at least 15 seconds and within 30 minutes.

A method of preparing a billet (1b) of a heat-resistant, creep-resistant aluminum alloy containing at least 10 mass % and not more than 30 mass % of silicon, at least 3 mass % and not more than 10 mass % of at least either iron or nickel in total, at least 1 mass % and not more than 6 mass % of at least one rare earth element in total and at least 1 mass % and not more than 3 mass % of zirconium while containing none of titanium, magnesium and copper, with the rest substantially containing aluminum,

• comprising a step of molding rapidly cooled alloy powder consisting of an aluminum alloy into a pressurized powder compact (1a) and thereafter performing hot plastic working on said pressurized powder compact (1a) thereby forming a billet (1b), wherein
• the time exposing said pressurized powder compact (1a) to a temperature of at least 450° C. before forming said billet (1b) is at least 10 seconds and within 20 minutes.