(1. 昆明理工大學 材料與冶金工程學院，昆明 650093；
(2. Advanced Materials Group, School of M3, University of Nottingham, Nottingham NG7 2RD, UK)
摘 要: 在常規(guī)熔體發(fā)泡法的基礎(chǔ)上，采用加入0.5%(質(zhì)量分數(shù))Mg、添加1%形核劑和發(fā)泡劑，經(jīng)(400 ℃, 6 h)+( 475 ℃, 1 h)氧化預(yù)處理、攪拌發(fā)泡50 s等措施，制備出平均孔徑1.03 mm、孔隙率75%、結(jié)構(gòu)均勻的小孔徑Al-9Si泡沫。孔徑細化機理分析表明，Mg的作用在于降低鋁熔體的表面張力，提高氣泡穩(wěn)定性；形核劑的作用在于增加氣泡非均勻形核的核心；發(fā)泡劑氧化預(yù)處理可以推遲和延緩發(fā)泡劑的分解，提高發(fā)泡劑的分散均勻性；攪拌發(fā)泡的作用是在發(fā)泡劑劇烈分解的中段，通過攪拌攪碎氣泡，減小平均孔徑。
關(guān)鍵字: 泡沫鋁；小孔徑；制備；機理
aluminum foam with fine cell structure
（1. Faculty of Materials and Metallurgical Engineering, Kunming University of Science and Technology,
Kunming 650093, China;
2. Advanced Materials Group, School of M3, University of Nottingham, Nottingham NG7 2RD, UK）
Abstract: Based on the general melt foaming processing, Al-9Si foam with cell diameter of 1.03 mm, porosity of 75% and uniform cell structure was fabricated through adding alloying element 0.5%(mass fraction)Mg, adding 1% nuclear forming agent and pre-heating foaming agent by (400 ℃, 6 h)+( 475 ℃, 1 h), stirring when foaming for 50 s. The cell structure refining mechanism shows that adding Mg decreases the surface tension of the aluminum alloy melt and hence to increase the bubble stabilization. Adding nuclear forming agent increases the nuclei of heterogeneous nucleation. Adding pre-heating foaming agent postpones its decomposition, hence to increase the uniform of foaming agent dispersion. Stirring within the middle stage of foaming agent rapid decomposition breaks up big bobbles to fine bobbles, hence to reduce mean cell diameter.
Key words: aluminum foam; fine cell diameter; fabricating; mechanism
