Control of texture in alumina by colloidal processing in a strong magnetic field
Control of texture in alumina by colloidal processing in a strong magnetic field
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DOI：
10.1016/j.stam.2006.01.014
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发表时间：
2006-01
影响因子：
5.5
通讯作者：
Tohru S. Suzuki;T. Uchikoshi;Y. Sakka
中科院分区：
文献类型：
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作者：
Tohru S. Suzuki;T. Uchikoshi;Y. Sakka
陶瓷材料的电学、机械和其他性能可以通过设计其微观结构来控制。通常很难利用磁场来调整弱磁性陶瓷（例如 Al 2 O 3 ）的微观结构；然而，随着超导磁体的发展，出现了通过磁场控制微观结构的可能性。在这篇综述论文中，我们介绍了一种通过强磁场和电场中的胶体加工进行陶瓷微观结构设计的新颖加工方法。我们证明，可以通过在强磁场中注浆铸造来制造织构化氧化铝，并且可以通过在强磁场中进行电泳沉积来生产具有不同晶体取向层的氧化铝/氧化铝层状复合材料。为了使用磁场控制质地，粉末在悬浮液中的良好分散是必要的，因为附聚颗粒之间的强大吸引力阻止悬浮液中的每个颗粒在磁场中旋转。取向程度取决于加工因素，如加热温度、悬浮液粘度等。Al 2 O 3 基体中的晶粒生长增强了晶体织构的发展。层状复合材料的弯曲强度取决于具有交替晶体取向层的多层微观结构的方向。裂纹扩展和断裂模式取决于具有受控晶体取向的层状复合材料中的微观结构方向。
Electrical, mechanical and other properties of ceramic materials can be controlled by designing their microstructures. It had generally been difficult to utilize a magnetic field for tailoring the microstructure in feeble magnetic ceramics, such as Al 2 O 3; however, the possibility of controlling the microstructure by a magnetic field occurred with the development of superconducting magnets. In this review paper, we introduce a novel processing for the microstructual design in ceramics by colloidal processing in a strong magnetic field and an electric field. We demonstrate that the textured alumina can be fabricated by slip casting in a strong magnetic field and the production of alumina/alumina laminar composites with different crystalline-oriented layers can be achieved by electrophoretic deposition in a strong magnetic field. In order to control the texture using a magnetic field, a good dispersion of powder in a suspension is necessary because a strong attractive force between the agglomerated particles prevents each particle in a suspension from rotating in the magnetic field. The degree of orientation depends on the processing factors, such as heating temperature, viscosity of suspension, etc. And the grain growth in Al 2 O 3 matrix enhances crystallographic texture development. The bending strength of the laminar composite depended on the direction of the multilayered microstructure with alternate crystalline-oriented layers. Crack propagation and fracture mode depend on the direction of microstructure in the laminar composite with controlled crystalline orientation.