采用金属/气体共晶定向凝固技术制备了藕状多孔铜,建立了凝固界面前沿溶质场模型, 采用模型计算分析了工艺参数(凝固速率、氢气压力和温度)对多孔铜结构参数(孔隙率和孔间距)和溶质浓度的影响, 并与试验结果进行了对比。结果表明: 保持氢气压力和温度不变时, 孔间距(λ)和凝固速率(v)呈vλ2=E(常数)的关系; 孔隙率主要受氢气压力的影响, 孔间距主要受凝固速率和氢气压力的共同影响; 模型计算结果和试验结果吻合较好; 随着氢气压力或凝固速率的升高, 固液界面前沿溶质富集程度越来越大, 而随着温度的升高, 溶质的富集程度越来越小。

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.