Figure 1: DF-TEM images before and after phase separation.
From: Mapping the evolution of hierarchical microstructures in a Ni-based superalloy
(a) Ordered (L12) γ′ precipitates in a disordered (A1) γ matrix after homogenizing Ni86.1Al8.5Ti5.4 at 1,548 K/4 h and ageing at 1,213 K for 0.75 h. The selected area electron diffraction pattern in the inset represents field of view of a. (b) γ spheres form when subsequently aged at 1,023 K for 6 h. (c) The γ spheres undergo a morphological transformation to plates after further ageing for 24 h. (d) The γ plates split the γ′ precipitates (indicated by arrows) when further aged for 96 h. (e,f) After split of γ′ precipitates, γ plates merge with the γ matrix after ageing for 192 and 384 h, respectively.
