Modeling and Simulation of Influence of Solidification Velocity on the Structure of Porous Copper and Aluminum

Abstract

In this article, a three-dimensional time-dependent model describing the evolution of single pore during the solid/gas eutectic unidirectional solidification process (also calledgasarprocess) was established. The mass transfer, bubble nucleation, pore growth and interruption were all considered in this model. The pore structure of lotus-type porous copper and aluminum were simulated under different solidification velocities. The results indicate that: coupled growth of both solid and gas phases can be achieved in a proper range of solidification velocities. The solidification velocity for Cu-H2system is dozens of that for Al-H2system when the pore diameter is similar to each other. The differences of the solute distribution coefficient (k0), diffusion coefficient (DL) and the constant of solubility of hydrogen (ξ(Tm)) in the melt are regarded as the main reasons of the big discrepancy of solidification velocity between Cu-H2and Al-H2systems.