BREAKING OF ROTATIONAL SYMMETRY DURING DECOMPOSITION OF ELASTICALLY ANISOTROPIC ALLOYS

The coarsening of a two-phase structure under the influence of interfa cial energy alone is characterized by an isotropic domain morphology w hich evolves in a self-similar way with time. We have studied the brea king of rotational symmetry due to additional anisotropic elastic misf it interactions in the model alloy Ni-Al-Mo. Introducing a dimensionle ss parameter rho as the ratio of elastic to interfacial energy, we sho w that, as long as rho < 1, the spherically averaged structure functio n still has time-scaling properties. Under these conditions, the spati al anisotropy of the domains increases linearly with rho and can be un derstood as a perturbation of the isotropic process at rho = 0.