中文摘要：

对熔体发泡法制备泡沫铝过程中无泡层的形成与控制进行研究，考察熔体中加入金属镁后的表面张力以及镁的加入对无泡层厚度的影响，结果表明：泡沫铝制备过程中无泡层的形成分为3个阶段，第一阶段为发泡初期短时间内形成，在这个过程中，气泡向上运动，部分液体残留在底部形成无泡层；第二阶段和第三阶段为气泡长大过程，由于液膜液体与Plateau边界处处存在压力差，促使液膜处的液体流向Plateau边界处，最后通过Plateau通道流向底部形成无泡层；向加入3%Ca（质量分数）的纯铝熔体中再加入0.5%Mg后，熔体的表面张力显著降低，泡沫体中无泡层的厚度得到很好的控制。

英文摘要：

The formation and control of bubble-free layer in Al foam block during the preparation was investigated, the surface tension of melt Mg was viewed, and the effect of Mg on the thickness of bubble-free layer was studied. The results show that there exist three processes for the formation of bubble-free layer. The first process is the initial stages of foaming, in this process, bubbles move upwards, and a portion of liquid remains at the bottom and becomes bubble-free layer. The second and the third processes are during the process of growth of bubbles, in these processes, bigger pressure of liquid stored in films makes liquid in films flow to plateau borders, and then the liquid in plateau borders flows to the bottom through plateau channels, and form bubble-free layer. When 0.5%Mg（mass fraction） is added into Al melt containing 3%Ca, the surface tension of melt decreases significantly, and the thickness of bubble-free layer in Al foam block can be controlled very well.