THE EFFECT OF FOREIGN PARTICLES ON THE INTERFACE SHAPE DURING SOLIDIFICATION OF CRYSTALS

ELIANA MABEL AGALIOTIS; MARIO ROBERTO ROSENBERGER; ALICIA ESTHER ARES; CARLOS ENRIQUE SCHVEZOV

Madrid

Congreso; XXII IUCr CONGRESS; 2011

The shape of a solidifying interface is generally affected when itencounters foreign inert particles. The degree of deformation dependson the morphology and physical properties of the particles [1-4]. Theoverall effect also affects the pushing and captures process, whenpushing is present.In the present report the interaction between particle and interfaceis analyzed by means of a mathematical model employing the finiteelement method. The effect on the interface of different particle shapesand relative thermal conductivities between particle and melt wasstudied.The results sown that for an isolating particle with respect to themelt the interface is convex in a degree that changes depending on theparticle shape and separation distance from the interface. The particlegeometries considered for simplicity were spherical, cylindrical,conical and semi-spherical. For a conducting particle the interfacechanges to concave.From the observation of the present results the trapping of theparticles by the solid starts in different places; for a conducting particlethe first points touching the solids are the corners while for an isolatingparticle this occurs at the particles center.The analyses of these observations indicate that the probability ofpore formation could be higher when isolating particle are present inthe melt.[1] A.A. Chernov, D.E. Temkin, Crystal Growth and Materials, North Holland,Amsterdam 1977, 3-77. [2] J.K. Kim, P.K. Rohatgi, Acta mater. 1998, 46(4),1115-l123. [3] A.V. Catalina, S. Mukherjee, D. Stefanescu, Metallurgical andMaterials Transactions 2000, A31, 2559-2568. [4] J.W. Garvin, Y. Yang, H.S.Udaykumar, International Journal of Heat and Mass Transfer, 2007, 50, 2969–2980.