Simulation of solidification of dendritic alloys with a porous media model

D. R. Poirier, J. C. Heinrich

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

'Macrosegregation' represents a class of defects in cast products and is of serious concern to both alloy producers and users. Most types of macrosegregation result from thermosolutal convection that takes place in the solid plus liquid and all-liquid regions of a solidifying alloy. Mathematical modeling of convection in solidifying alloys has been done since about 1970, but only in the past five years has analysis of thermosolutal convection been incorporated into solidification theory. This has resulted in simulations, which treat the solid plus liquid region as a porous medium of variable porosity and permeability. Simulations include scenarios in which the convection is strong enough to make channels in the solid plus liquid region, and these channels are responsible for making localized segregates known as 'freckles.' Using Pb-10 wt pct Sn as a model alloy, we simulated vertical solidification with two different solidification rates; both exhibited freckles. By an increase of the cooling rate at the bottom surface, convection was suppressed for the first minute of solidification, but thereafter the convection was sufficient to cause the formation of freckles.

Original languageEnglish (US)
Title of host publicationTopics in Heat Transfer
PublisherPubl by ASME
Pages167-174
Number of pages8
ISBN (Print)0791809323
StatePublished - Dec 1 1992
Event28th National Heat Transfer Conference and Exhibition - San Diego, CA, USA
Duration: Aug 9 1992Aug 12 1992

Publication series

NameAmerican Society of Mechanical Engineers, Heat Transfer Division, (Publication) HTD
Volume206-2
ISSN (Print)0272-5673

Other

Other28th National Heat Transfer Conference and Exhibition
CitySan Diego, CA, USA
Period8/9/928/12/92

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ASJC Scopus subject areas

  • Mechanical Engineering
  • Fluid Flow and Transfer Processes

Cite this

Poirier, D. R., & Heinrich, J. C. (1992). Simulation of solidification of dendritic alloys with a porous media model. In Topics in Heat Transfer (pp. 167-174). (American Society of Mechanical Engineers, Heat Transfer Division, (Publication) HTD; Vol. 206-2). Publ by ASME.