Electrophoretic shaping of sub-micron alumina in ethanol

The electrophoretic deposition (EPD) method was used to shape sub-micron Al2O3 green body in ethanol. The uniformity of the final deposit was affected by the colloidal properties of the suspension. Therefore, the stability of Al2O3 suspension in ethanol was studied in terms of electrophoretic mobility, viscosity and conductivity. The EPD kinetics were further investigated with different electrical conditions. The effect of cellulose acetate membrane on deposit was also studied. The green body with a relative density of about 60 %TD was associated with a narrow pore size distribution, indicating a high homogeneity of particle coordination. After presintering and HIPing at 1250 °C, a fully dense alumina ceramic was obtained with an average grain size of 0.65 μm.