Transport properties and transport phenomena in casting nickel superalloys

S. D. Felicelli, P. K. Sung, D. R. Poirier, J. C. Heinrich

Research output: Contribution to journalArticle

4 Scopus citations

Abstract

Nickel superalloys that are used in the high-temperature regions of gas-turbine engines are cast by directional solidification (DS). In the DS processes, the castings are cooled from below, and three zones exist during solidification: (1) an all-solid zone at the bottom, (2) a "mushy zone" that is comprised of solid and liquid material, and (3) an overlying all-liquid zone. Computer simulations can be useful in predicting the complex transport phenomena that occur during solidification, but realistic simulations require accurate values of the transport properties. In addition to transport properties, the thermodynamic equilibria between the solid and liquid during solidification must also be known with reasonable accuracy. The importance of using reasonably accurate estimations of the transport properties is illustrated by two-dimensional simulations of the convection during solidification and the coincidental macrosegregation in the DS castings of multicomponent Ni-base alloys. In these simulations, we examine the sensitivity of the calculated results to measured partition ratios, thermal expansion coefficients, and viscosities that are estimated by regression analyses and correlations of existing property data.

Original languageEnglish (US)
Pages (from-to)1657-1669
Number of pages13
JournalInternational Journal of Thermophysics
Volume19
Issue number6
StatePublished - Nov 1998

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Keywords

  • Directional solidification
  • Freckles
  • Multicomponent alloys
  • Nickel superalloys

ASJC Scopus subject areas

  • Condensed Matter Physics

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