Status and development of powder metallurgy nickel-based disk superalloys

Abstract

AbstractNickel-based superalloys are crucial materials for the development of aero-engine components, since their excellent properties can meet the demands of turbine disks. For the formation of such alloys, powder metallurgy is considered as the ideal method, due to the resultant uniform composition and structure, fine grain, high yield strength, and good fatigue performance. This paper provides a critical review of the development of powder metallurgy nickel-based disk superalloys, their composition, as well as the evolution of the nickel-based superalloys' microstructure in the past few decades. Moreover, the influence of various elements on the material properties and the three major defects of powder metallurgy superalloys are reviewed. The analysis indicates that these defects may be directly or indirectly caused by the quality of the powder. Therefore, the innovative powder techniques of electrode induction melting gas atomization and spark plasma discharge spheroidization are presented, in order to prepare ceramic-free and superfine nickel-based superalloy powders. The powders prepared by electrode induction melting gas atomization and spark plasma discharge spheroidization have been found to be beneficial in improving the properties of powder metallurgy nickel-based disk superalloys.