A model for formation of eutectic composites by the method of directional solidification

Abstract

A continuum model for the formation of ceramic two-component eutectic composites in the process of directional crystallization is proposed. The problem of modeling the formation of a composite is formulated as a modified one-dimensional Stefan problem, where the boundary condition at the crystallization front takes into account, along with the specific latent heat of crystallization, the energy contributions associated with the formation of the composite microstructure. Solutions of the modified Stefan problem are used to establish general relations between the structural parameters of the composite and the parameters that determine the solidification process (the pulling velocity and the position of the crystallization front). Estimates are made for the composites formed from LaB₆―ZrB₂ eutectic.