权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Elucidation of electrophoretic deposition behavior of particles suspended in aqueous media and characterization of highly structure-ordered ceramics

阐明悬浮在水介质中的颗粒的电泳沉积行为以及高度结构有序陶瓷的表征

基本信息

批准号：
15560593
负责人：
UCHIKOSHI Tetsuo
金额：
$ 2.37万
依托单位：
National Institute for Materials Science
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2005
项目状态：
已结题

项目摘要

Electrophoretic deposition characteristics of ceramic aqueous suspensions were studied using palladium electrodes to suppress the hydrogen bubble generation at a cathode which disturbed the electrophoresis of the particles and suppress their deposition. The apparent transport number of the surface-charged particles was very low and they were not dominant carrier species in the solvent. In the EPD at a constant current mode, applied voltage between the electrodes varied with the pH of the solvent or the ion conductivity. Lower pH gave lower deposition rate but higher particle packing.Mechanical and electrical properties of the zirconia/alumina laminate composites fabricated by EPD from aqueous suspensions were characterized. Crack deflection within the alumina layers of the laminate composites was observed because of high compressive residual stress in the alumina layers. The 3Y TZP/alumina laminate composite showed the electrical properties of 3Y-TZP in the parallel direction to the alumina layers and those of alumina in the perpendicular direction. Electrical conductivity measurement well reflected the laminar structure of the laminate composite. It was demonstrated that EPD was well suited to produce layered composites with strongly bonded interfaces.The fabrication of crystalline-textured alumina ceramics were also attempted by EPD in a strong magnetic field using a deflocculated suspension of single crystalline alumina particles. The crystalline orientation in the textured ceramics could be controlled by varying the angle between the vectors B and E (ψ B-E) during EPD. Average orientation angle estimated from the XRD data was fairly consistent with the angle ψ B-E. The cross sectional microstructures of the laminate composites clearly showed the changes in crystalline texture at the interfaces between the layers. It was demonstrated that the EPD in a strong magnetic field was a promising processing technique for making crystalline textured ceramics.

研究了陶瓷悬浮液的电泳沉积特性，采用钯电极抑制阴极产生的氢气泡，氢气泡干扰颗粒的电泳并抑制它们的沉积。表面带电粒子的表观输运数非常低，它们不是溶剂中的主要载体物种。在恒流模式下，电极之间施加的电压随溶剂的pH或离子电导率而变化。pH值越低，沉积速率越慢，颗粒堆积越大。研究了用电泳沉积法制备的氧化锆/氧化铝层状复合材料的力学性能和电学性能。由于氧化铝层中的高压缩残余应力，观察到层压复合材料的氧化铝层内的裂纹偏转。3 Y-TZP/Al_2O_3层状复合材料在平行于Al_2O_3层的方向上具有3 Y-TZP的电学性能，在垂直于Al_2O_3层的方向上具有Al_2O_3的电学性能。电导率的测量很好地反映了层状复合材料的层状结构。结果表明，EPD技术适合于制备界面结合较强的层状复合材料，并在强磁场中利用单晶氧化铝颗粒悬浮液制备了具有晶体织构的氧化铝陶瓷。在EPD过程中，可以通过改变矢量B和E之间的角度（θ B-E）来控制织构陶瓷中的晶体取向。从XRD数据估计的平均取向角与角θ B-E相当一致。层压复合材料的横截面微观结构清楚地显示了层间界面处晶体织构的变化。结果表明，强磁场中的EPD是一种很有前途的制备织构陶瓷的工艺技术。