李瑛
,
钟健
,
杨霞珍
,
蓝国钧
,
唐浩东
,
刘化章
新型炭材料
doi:10.1016/S1872-5805(11)60071-1
以SBA-15介孔硅为模板,硼酸为扩孔剂,调控合成出不同孔径尺寸的半石墨化有序介孔炭.采用X射线衍射仪(XRD)、氮气吸附、透射电子显微镜(TEM)、扫描电子显微镜(SEM)、热重(TG),以及拉曼(Raman)光谱等手段对样品的成分、结构和形貌进行了分析.结果表明:通过合成过程添加硼酸的方法可以实现对介孔炭材料的孔径在3nm～7nm范围内精确调控,而且合成的介孔炭材料具有半石墨化的墙壁结构.该方法简单易行,对介孔炭材料的孔结构调控合成具有很好的应用价值.
关键词:
有序介孔炭
,
孔径可调
,
半石墨化
,
硼酸
P.Bian
,
Dong-Ying Ju
材料科学技术（英文）
Magnetite (Fe3O4) of ferrite magnetic materials has attracted attentions arising by the chip coil electronic material. However, its industrial applications have been limited by the need of high temperature sintering under reduced pressure or vacuum. In order to develop the process method of low-cost and energy saving with high strength and high magnetism of the magnet, a new low temperature sintering method during CO2 gas and adding small amount of boric acid (H3BO3) are proposed. Here, the superfine magnetite powder was fabricated by decomposition from ferrous oxalate at 500℃ in CO2 gas. The ferrous oxalate was synthesized using iron chloride and ammonium oxalate with the liquid phase precipitation. The magnetite powder compact was produced by Newton press and CIP (cold isostatic press) after adding small amount of boric acid. In this study, the effects of the additive on the mechanical and magnetic properties of the sintered magnet were also evaluated. By characteristic evaluation of the magnet, the validity of the proposed new low-temperature sintering process and the optimal process conditions were confirmed.
关键词:
Ferrite magnet
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