Three-dimensional simulations of freckles in binary alloys

S. D. Felicelli, J. C. Heinrich, D. R. Poirier

Research output: Contribution to journalArticle

51 Scopus citations

Abstract

A tridimensional finite-element model was developed to calculate the thermosolutal convection and macrosegregation during the solidification of dendritic alloys. A single set of conservation equations is solved in the mushy zone, all-liquid, and all-solid regions without internal boundary conditions. The model is applied to simulate the directional solidification of a Pb-Sn alloy in cylinders of square and circular cross section. The calculations are started from an all-liquid state and the evolution of convection, solute and energy transport, and the mushy zone growth are followed in time. The results show details of the channels, which result in freckles, that are not observable in existing two-dimensional simulations. Several qualitative features of channels and freckles previously observed in experiments with transparent systems, like chimney convection, preference of channels to be on surfaces, and enhanced solid growth at the channel mouth ("volcanoes") are successfully reproduced.

Original languageEnglish (US)
Pages (from-to)879-888
Number of pages10
JournalJournal of Crystal Growth
Volume191
Issue number4
DOIs
StatePublished - Aug 1 1998

    Fingerprint

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Inorganic Chemistry
  • Materials Chemistry

Cite this