Ceramics With Ultra‐Low Density Fabricated by Gelcasting: An Unconventional View
Ceramics With Ultra‐Low Density Fabricated by Gelcasting: An Unconventional View
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DOI：
10.1111/j.1551-2916.2007.01915.x
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发表时间：
2007-11
影响因子：
3.9
通讯作者：
R. Chen;Yong Huang;Chang-An Wang;Jianqiang Qi
中科院分区：
文献类型：
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作者：
R. Chen;Yong Huang;Chang-An Wang;Jianqiang Qi
凝胶注模成型是制备高密度陶瓷零件的常规方法，而本文采用这种方法成功地制备了超低密度(理论密度为8%-40%)的氧化铝陶瓷。在本研究中，丙烯酰胺在固含量为5%~15%的叔丁醇/Al_2O_3浆料中实现聚合。超低密度坯体的干燥收缩很小，可获得较高的坯体强度(1~3 Mpa)。通过选择不同的初始固含量和烧结温度，可以有效地控制陶瓷的微观结构，气孔率在60%~92%之间，孔径在0.1~2.2μm之间，烧结后的Al_2O_3具有高的开孔率(90%)、高的比表面积(14m2/g)和高的抗压强度(>；10 Mpa)，这是由于Al_2O_3颗粒的连接所致。这项技术被认为具有潜在的应用前景，并引入了凝胶注模成型的一个新的应用领域。
Gelcasting is conventionally used to acquire high-density ceramic parts; however, in this work, alumina (Al2O3) ceramics with ultra-low density (8%–40% theoretical density) were successfully fabricated by this method. In this research, polymerization of acrylamide was realized in tert-butyl alcohol/Al2O3 slurries with solid loading ranging from 5 to 15 vol%. Green bodies with ultra-low density could be dried with very small shrinkage, and relatively high green strengths (1–3 MPa) were achieved. By choosing different initial solid loadings and sintering temperatures, ceramic microstructures could be effectively controlled, with the porosity ranging from 60% to 92% and pore sizes from 0.1 to 2.2 μm. Sintered Al2O3 showed high open porosity (90%), high specific area (14 m2/g) and high compression strength (>10 MPa), which was attributed to the connection of Al2O3 particles. This technique is considered potentially useful in many applications, and introduces a new application field of gelcasting.