Numerical Simulation of Solute Field before Solidification Interface of Lotus Root-typed Porous Copper

Lotus root-typed porous copper was prepared by directional solidification of metal/gas eutectic technology. A model of solute field before solidification interface was established to analyze the effects of process parameters (solidification rate, hydrogen pressure and temperature) on the porous copper's structure parameters (porosity and inter-pore spacing) and solute concentration, and the calculated results were compared with experimental results. The results show that the theoretical relation between the inter-pore spacing and solidification rate could be described as a simple expression vλ2=E(constant) when the hydrogen pressure and temperature were constant. Porosity was affected mainly by hydrogen pressure and inter-pore spacing was affected by solidification rate and hydrogen pressure. By comparison, the calculated results and tested ones are in good agreement. The higher the hydrogen pressure or the solidification rate, the more the solute enrichment before solid-liquid interface frontier; the higher the temperature, the less the solute enrichment degree.