The effects of elastic stress on microstructural development: the three-dimensional microstructure of a γ–γ′ alloy Original Research Article

We investigate the three-dimensional structure of a model γ–γ′ alloy using serial sectioning and digital reconstruction. The particles align in parallel two-dimensional sheets along the <100> crystallographic directions. The sheets in different regions of the microstructure are aligned along different <100> crystallographic directions. A variety of particle morphologies are observed. These morphologies are relatively independent of particle size, indicating a significant departure from single-particle equilibrium morphologies. The primary determinant of particle morphology appears to be the interparticle elastic interactions, both within sheets of particles and at the intersections of sheets. There is no evidence of particle coalescence despite the small interparticle separation.