L Zhang et al. / Journal of the European Ceramic Society 30(2010)1195-1202 喝() 0001 1100 1210 0110 (d)0001 2110 max=2.5 2213 1100 12001101210 2110 max=1.638 0001 100 1 01101210 min=0.191 70 um Fig. 6. EBSD data on a textured alumina. EBSD pattern of the perpendicular cross-section of the sample formed(a)in vertical cell with stirred suspension; (b)in orizontal cell with suspension fowing through; (c) corresponding colour coded map and (d)[001] IPF for(a), and(e)100 1]IPF for(b) suspension in a horizontal cell with a deposition electrode on the top(configuration 3)was investigated. In this case, the down- ward gravity force on the platelets is counteracted by the upward electric field force and the platelet alignment in the deposit is mainly induced by the electric field force. As shown in Fig. 7, the basal planes of the platelets are well aligned parallel to the depo- sition electrode surface. The electric field force can orientate platelets in two possible ways, i.e., during electrophoresis or One possible mechanism is that the electric field force aligns the platelets during electrophoresis due to the charge distribution on the platelet surfaces. The electrical charge on the basal plane of the platelets is different from that on the side plane due to t large difference in surface area. Under the present experimental conditions at pH 1l. 4, all platelet surfaces are negatively charged although the natural charge density could be different between the basal plane and prismatic plane. 8-20 The electric field force 10 am applied on the basal plane is therefore larger than on the pris- matic plane. The platelet alignment mechanism may depend on Fig. 7. SEM micrograph of a perpendicularly cross-sectioned ceramic obtained the polarisation of the electrical double layer in the electric field by upward EPD in a horizontal cell without suspension flowing through.L. Zhang et al. / Journal of the European Ceramic Society 30 (2010) 1195–1202 1199 Fig. 6. EBSD data on a textured alumina. EBSD pattern of the perpendicular cross-section of the sample formed (a) in vertical cell with stirred suspension; (b) in horizontal cell with suspension flowing through; (c) corresponding colour coded map and (d) [0 0 1] IPF for (a), and (e) [0 0 1] IPF for (b). suspension in a horizontal cell with a deposition electrode on the top (configuration 3) was investigated. In this case, the down￾ward gravity force on the platelets is counteracted by the upward electric field force and the platelet alignment in the deposit is mainly induced by the electric field force. As shown in Fig. 7, the basal planes of the platelets are well aligned parallel to the depo￾sition electrode surface. The electric field force can orientate the platelets in two possible ways, i.e., during electrophoresis or upon deposition. One possible mechanism is that the electric field force aligns the platelets during electrophoresis due to the charge distribution on the platelet surfaces. The electrical charge on the basal plane of the platelets is different from that on the side plane due to the large difference in surface area. Under the present experimental conditions at pH 11.4, all platelet surfaces are negatively charged although the natural charge density could be different between the basal plane and prismatic plane.18–20 The electric field force applied on the basal plane is therefore larger than on the pris￾matic plane. The platelet alignment mechanism may depend on the polarisation of the electrical double layer in the electric field, Fig. 7. SEM micrograph of a perpendicularly cross-sectioned ceramic obtained by upward EPD in a horizontal cell without suspension flowing through