Electrophoretic Deposition of Zirconia on Alumina for Molten Salt Applications

Abstract

Electrophoretic deposition of zirconia on alumina crucibles was carried out at constant voltage conditions from zirconia suspension prepared with isopropyl alcohol. The phase purity and surface morphology of coated samples were characterized by X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy coupled with energy dispersive X-ray analysis. The maximum deposit yield was obtained with a direct current potential of 125 V. The substrates pretreated with acid-base and subjected for sintering temperature 1100°C for one hour showed excellent adhesion on both sides. The X-ray diffraction results showed the monoclinic phase is the major component and the average crystallite sizes of coated deposits were found as ~4.1μ. The absorption bands observed at 463 cm -1 , 743 cm -1 and at 486 cm -1 confirm the presence of ZrO 2 phases. The intensity of bands observed at 3415 cm -1 and 1634 cm -1 were gradually decreased due to sintering confirm the stretching and deformation of the O-H bond. The surface analysis showed that the zirconia particles are of uniform size and there is a considerable agglomeration of the particles on alumina substrates. The energy dispersive analysis indicated the presence of elemental Zr and O and sintering causes the penetration of agglomerated zirconia particles into the micropores present on alumina substrates and is responsible for excellent adhesion.