Figure 1

(a) Cr-M edge EFTEM low magnification image showing the typical microstructure in Rene88DT slow cooled from $1150°\mathrm{C}$ (at $30°\mathrm{C}/\min $) and aged 50 h at $760°\mathrm{C}$; the larger particles represent the primary ${\gamma }^{\prime }$ while the smaller particles represent the secondary ${\gamma }^{\prime }$, (b) HRSTEM image along the [100] zone showing the interface between a primary ${\gamma }^{\prime }$ precipitate and $\gamma$ matrix; the insets show Fourier Transforms indicating order within the ${\gamma }^{\prime }$ and lack of order within the $\gamma$ phase, (c) higher magnification filtered HRSTEM image showing the structural and compositional transition across the $\gamma /{\gamma }^{\prime }$ interface, (d) schematic diagram showing the ${\gamma }^{\prime }$ and $\gamma$ unit cells, with the (002) plane indicated; alternating (002) rows of Ni and ($\mathrm{Ni}+\mathrm{Al}/\mathrm{Ti}$) atoms in the ${\gamma }^{\prime }$ can be visualized, while no such order exists in the $\gamma$ phase.Reuse & Permissions

Figure 2

(a) HRSTEM image from box $ABCD$ delineated in Fig. 1c. (b) Averaged intensity profiles across row AB through CD showing the transition from ordered ${\gamma }^{\prime }$ to disordered $\gamma$. (c) Progressive intensity ratios showing the order-disorder transition and compositional width of the interface.Reuse & Permissions

Figure 3

(a) Al 10% (red) and Co 19% (blue) isosurfaces depicting morphology of the ${\gamma }^{\prime }$ precipitate used in 3DAP analysis; the red area is indicative of the primary ${\gamma }^{\prime }$ precipitate, (b) and (c) higher magnification views showing the stacking of alternate (002) Al planes within the ${\gamma }^{\prime }$. (d) Proximity histogram depicting the compositional transition across the $\gamma /{\gamma }^{\prime }$ interface; the area used in the analysis is indicated by the arrow in the inset.Reuse & Permissions