Influence of the shape of the particles in the solidification of composite materials

AGALIOTIS, E. M.; MARIO ROBERTO ROSENBERGER; ARES, A.E.; SCHVEZOV, C. E.

Procedia materials

Elsevier

Lugar: Amsterdam; Año: 2012 vol. 1 p. 58 - 63

1877-7058

The shape of a solidifying interface is generally affected when it encounters foreign inert particles. The degree of deformation depends on the morphology and physical properties of the particles, the melt, the solid and the external fields (Chernov et al.1977, Kim et al. 1998, Catalina et al. 2000, Garvin 2007) , affecting the pushing and captures process of the particles. The particle can be trapped by the interface at slower solidification velocities than that predicted by simple models which do not include any deformation of the interface. In all cases this interaction strongly determines the particle size distribution and the physical and physicochemical properties of the final material. In the present report the interaction between particle and interface is analyzed by means of a mathematical model employing the finite element method. The effect on interface shape of different particle shapes and relative thermal conductivities between particle and melt was studied. Thermal field results show that when the particle is more conductive than the melt, the interface is concave. Comparing the concaves interfaces for different particle shapes is observed that, when the particle is not spherical the separation particle-interface at the edge of the particle is the smallest. As a consequence of this phenomenon, which occurs in non-spherical particles, there is a remaining amount of melt between particle and solid which is the last in solidify.