Fabrication of magnesium aluminate (MgAl2O4) spinel foams
Fabrication of magnesium aluminate (MgAl2O4) spinel foams
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DOI：
10.1016/j.ceramint.2011.03.068
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发表时间：
2011-09
影响因子：
5.2
通讯作者：
I. Ganesh
中科院分区：
文献类型：
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作者：
I. Ganesh
本文报道了一种利用固体含量为 30-35vol% 的水悬浮液制造铝酸镁 (MgAl2O4) 尖晶石 (MAS) 泡沫的新颖加工路线。由氧化铝 (71.8%) 和氧化镁 (28.2%) 在 1400°C 下形成的化学计量 MAS 粉末在 H3PO4 和 Al(H2PO4)3 的乙醇溶液中在 80°C 下表面钝化 24 小时以防止水解。使用表面钝化的 MAS 粉末，借助氢氧化四甲铵 (TMAH) 和聚丙烯酸铵盐 (Duramax D-3005) 作为分散剂，制备固体含量为 30–35vol.% 的稳定水悬浮液。利用 N-十六烷基-N,N,N-三甲基溴化铵 (CTMAB) 的水溶液通过机械发泡在 MAS 水悬浮液中产生泡沫。然后通过在环境条件下引入聚合引发剂和催化剂，将液体泡沫固结在无孔模具中。然后将干燥（>90°C 24 小时）的 MAS 泡沫在 1650°C 下烧结 1 小时。为了进行比较，本研究还制备了由未钝化化学计量 MAS 粉末制成的致密 MAS 体，以及由氧化铝制成的致密 MAS 体和泡沫体。 MAS 和氧化铝陶瓷的烧结性能通过各种方法进行了表征，本文对所得结果进行了介绍和讨论。烧结的 MAS 泡沫的孔隙率约为 74-76%，压缩强度约为 4-7.2MPa，与文献中报道的其他陶瓷泡沫的值一致。
This paper reports on a novel-processing route for fabricating magnesium aluminate (MgAl2O4) spinel (MAS) foams from aqueous suspensions containing 30–35vol.% solids loading. A stoichiometric MAS powder formed from alumina (71.8%) and magnesia (28.2%) at 1400°C was surface passivated against hydrolysis in an ethanol solution of H3PO4and Al(H2PO4)3at 80°C for 24h. Stable aqueous suspensions with 30–35vol.% solids loading were prepared using the surface passivated MAS powder with the help of tetra-methylammonium hydroxide (TMAH) and an ammonium salt of polyacrylic acid (Duramax D-3005) employed as dispersing agents. An aqueous solution of N-cetyl-N,N,N-trimethylammonium bromide (CTMAB) was utilized to create foam in aqueous MAS suspensions by mechanical frothing. Liquid foam was then consolidated in non-porous moulds by introducing a polymerization initiator and a catalyst under ambient conditions. Dried (at >90°C for 24h) MAS foams were then sintered for 1h at 1650°C. For comparison purposes, dense MAS bodies out of an un-passivated stoichiometric MAS powder, and, dense as well as foams out of alumina were also prepared in this study. The sintered properties of MAS and alumina ceramics were characterized by various means and thus obtained results are presented and discussed in this paper. The sintered MAS foams exhibited a porosity of about 74–76% and a compressive strength of about 4–7.2MPa inline to values reported for other ceramic foams in the literature.