Theoretical and experimental investigations on elastic interactions between ??-precipitates in a Ni-Al alloy

Elastic interaction energies between two identical inhomogeneous plates in an anisotropic matrix were calculated with respect to particle separation distance and alignment orientation on the basis of the microscopic theory of elasticity developed by Yamauchi and de Fontaine. Four types of plate-arrangement along the cube directions; two plates whose faces were mutually parallel, two plates which were arranged on a cube plane as a raft, two plates which were perpendicularly arranged with face—edge configuration and two plates which were perpendicularly aligned with edge—edge configuration were energetically stable, while other arrangements were not stable. Compared with experimental observations on the local arrangement of γ′plates in a Ni-Al single crystal, the calculated results were confirmed to be qualitatively correct.