A Self-Consistent Theory of Steady-State Lamellar Solidification in Binary Eutectic Systems.

Abstract

The potential theoretic methods recently developed at NRL for solving the diffusion equation are applied to the problem of lamellar eutectic solidification. This approach leads to a set of coupled nonlinear integro- differential equations for the shape of the solid-liquid interface and the solute concentration on the interface. The general characteristics of the solutions to these equations are discussed, and in particular it is shown that lamellar solutions may not be possible when the ratio of thermal gradient to freezing rate is less than some critical value which depends on the phase properties and the phase fraction. Selected numerical results are presented for the Pb-Sn eutectic system and compared to the results of Jackson and Hunt, who assumed a planar interface model. It is shown that the planar interface model can be a source of considerable error under certain conditions, and that the self-consistent model provides additional theoretical insights.

Document Details

Document Type
Technical Report
Publication Date
Nov 01, 1974
Accession Number
ADA001704

Entities

People

  • G. E. Nash
  • M. E. Glicksman

Organizations

  • United States Naval Research Laboratory

Tags

DTIC Thesaurus Topics

  • Differential Equations
  • Diffusion
  • Equations
  • Equations Of State
  • Freezing
  • Isothermal Processes
  • Mathematics
  • Solidification
  • Steady State

Readers

  • Finite Element Method (FEM) for solving Partial Differential Equations (PDEs)
  • Powder metallurgy of Titanium alloys.
  • Theoretical Analysis.