The genetic evolution behavior of carbides in powder metallurgy FGH96 Ni-based superalloys

Understanding the evolution of carbides in FGH96 Ni-based superalloys during solidification carries profound significance in the context of regulating prior particle boundaries (PPBs) formation and enhancing the mechanical properties of the alloys. This study utilized interrupted sintering to produce sintering neck interfaces at various stages and systematically investigated the evolution of carbides during sintering in conjunction with an analysis of the surface characteristics of the original alloy powders. The results reveal that the original powder surface contains large amounts of M(Ti, Nb)C precipitates, which could serve as a source for the MC particles appearing at PPBs. Typically, the formation of the typical core-shell structure of the MC particle with the oxides as the core is due to the growth of MC at subsequent consolidation process, and the MC particle would engulf the surrounding oxide particles during sintering. This mechanism differs from the precipitation of carbides with oxides as nucleation sites during sintering, and this work provides a new insight about the evolution of the carbides.