Artículos de revistas
Multigrain and Multiphase Mathematical Model for Equiaxed Solidification
Fecha
2015-01Registro en:
Metallurgical and Materials Transactions A, Warrendale, v. 46A, n.1, p. 377-395, 2015
10.1007/s11661-014-2620-7
Autor
Martorano, Marcelo de Aquino
Aguiar, Davi Teves
Arango, Juan Marcelo Rojas
Institución
Resumen
A deterministic multigrain and multiphase model of equiaxed solidification of binary alloys is
proposed, implemented, and analyzed. An important feature of the present model is the creation
of classes of dendritic and globulitic grains according to their instantaneous sizes during
solidification. Globulitic and dendritic grain growth, coarsening of secondary dendrite arms,
distribution of nucleation undercoolings, and equiaxed eutectic growth are consistently included
in the model equations. Important model assumptions are uniform temperature, negligible
liquid convection, and negligible grain movement. Calculated cooling curves, solid fraction
evolution, average grain sizes, and eutectic fractions agree well with predictions of previous
models for dendritic and globulitic equiaxed grains. Predicted grain sizes decrease with an
increase in cooling rate for an Al-2.12 pct Cu alloy and with an increase in Si concentration up
to 3 pct for Al-Si alloys, agreeing quantitatively with experimental results. Simulations for an
Al-7 pct Si alloy predict that an increase in grain size correlates with an increase in the magnitude
of the recalescence observed in cooling curves. These calculations agree well with
experimental results when the transition from a globulitic to a dendritic morphology occurs in
the model before the minimum temperature of recalescence is reached