Patent ID: 8889064

Claim:
A method for preparing a part of nickel-based superalloy by powder metallurgy, including the following steps: elaboration of a nickel-based superalloy with a composition capable of providing hardening by double precipitation of a gamma′ phase and of a gamma″ or delta phase; atomization of a melt of said superalloy in order to obtain a powder; sifting said powder for extracting the particles thereof having a predetermined grain size; introducing the powder into a container to form a powder and container assembly; closing and applying a vacuum to the container; densification of the powder and of the container by pressurizing the powder and container assembly in order to obtain one of an ingot or a billet; hot forming said ingot or said billet; wherein before the step for densifying the powder and the container, a heat treatment step is performed for at least 4 hours, at a pressure causing densification of the powder of less than or equal to 15% of the initial volume, this treatment taking place under an inert and non-reactive atmosphere at a temperature both above 1,140° C. and at least 10° C. less than the solidus temperature of the superalloy.