BREAKING OF ROTATIONAL SYMMETRY DURING DECOMPOSITION OF ELASTICALLY ANISOTROPIC ALLOYS

The coarsening of a two-phase structure under the influence of interfacial energy alone is characterized by an isotropic domain morphology which evolves in a self-similar way with time. We have studied the breaking of rotational symmetry due to additional anisotropic elastic misfit interactions in the model alloy Ni-Al-Mo. Introducing a dimensionless parameter rho as the ratio of elastic to interfacial energy, we show that, as long as rho < 1, the spherically averaged structure function still has time-scaling properties. Under these conditions, the spatial anisotropy of the domains increases linearly with rho and can be understood as a perturbation of the isotropic process at rho = 0.