(東北大學(xué) 教育部材料先進(jìn)制備技術(shù)工程研究中心，沈陽 110004)
摘 要: 對(duì)熔體發(fā)泡法制備泡沫鋁過程中無泡層的形成與控制進(jìn)行研究，考察熔體中加入金屬鎂后的表面張力以及鎂的加入對(duì)無泡層厚度的影響，結(jié)果表明：泡沫鋁制備過程中無泡層的形成分為3個(gè)階段，第一階段為發(fā)泡初期短時(shí)間內(nèi)形成，在這個(gè)過程中，氣泡向上運(yùn)動(dòng)，部分液體殘留在底部形成無泡層；第二階段和第三階段為氣泡長大過程，由于液膜液體與Plateau邊界處處存在壓力差，促使液膜處的液體流向Plateau邊界處，最后通過Plateau通道流向底部形成無泡層；向加入3%Ca(質(zhì)量分?jǐn)?shù))的純鋁熔體中再加入0.5%Mg后，熔體的表面張力顯著降低，泡沫體中無泡層的厚度得到很好的控制。
關(guān)鍵字: 泡沫鋁；熔體發(fā)泡法；無泡層；黏度；表面張力
（Key Laboratory of Ministry of Education for Advanced Preparing Technique of Materials,
Northeastern University, Shenyang 110004, China）
Abstract: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.
Key words: Al foam; melt foaming method; bubble-free layer; viscosity; surface tension
