(东南大学 材料科学与工程系， 南京 210096)
摘 要: 应用图像识别与处理技术，描述了多孔铝合金的面孔隙率及体孔隙率； 研究了渗流法制备的多孔铝合金沿长度方向的孔隙率梯度， 并对整体孔隙率的均匀度进行了估计。 研究结果表明： 多孔铝合金的中上部孔隙率最高，顶端次之， 底端最低。 多孔铝合金的孔隙率梯度主要是由渗流驱动压力梯度与凝固顺序所决定， 而颗粒的自然堆积密度影响相对较小。 但通过振动控制方法， 调整颗粒堆积密度，可以有效地改善多孔铝合金的孔隙率梯度， 使孔隙率梯度绝对值平均由6.5%降至2.2%。
关键字: 多孔铝合金； 孔隙率； 孔隙率梯度
（Department of Materials Science and Engineering,
Southeast University, Nanjing 210096, China）
Abstract: Through image processing technique, the planar porosity, volume porosity of porous aluminium and porosity gradient along the length of porous aluminium alloy made by the negative pressure infiltration process were studied. The uniformity of the whole porosity was estimated. The results show that the porosity at the middle-superior part is the largest, at the bottom is the smallest, at the top is in the middle. The porosity gradient of porous aluminium is mostly affected not only by the spontaneous stacking density of granules, but also by the infiltration pressure gradient and solidification sequence. The porosity gradient can be improved effectively by changing the stacking density of granules through the vibration method, and the absolute value of porosity gradient can be reduced to 2.3% from 6.8%.
Key words: porous aluminium alloy; porosity; porosity gradient
