Abstract
The microstructural changes that occur during static annealing at 1311K of the nickel-base superalloy IN-100 are described. Samples were prepared from an extruded powder consolidate which had been worked in the temperature range 1348–1388 K. The microstructure was examined in detail in the as-extruded condition and after static annealing for 1.5 h at 1311K using both transmission and scanning electron microscopy. Additionally, the microstructures of specimens deformed superplastically at 1311K were examined, and showed that both the γ- and γ′-phases recrystallize and that recrystallization is initiated near prior particle boundaries where high localized strains and diffusion rates exist. Recrystallization is seen to advance on a well defined front. A mechanism for recrystallization is proposed which accounts for the present observations.
Get full access to this article
View all access options for this article.