Transactions of the INDIAN CERAMIC SOCIETY Vol. 55 1996
Formation of Yttria (10 mol o/o) Doped Zirconia
Coating on Zircaloy Substrate by Sol-Gel
Technique and its Characterisation
S. RAMANATHAN, S. K. Rov, R. BHAT AND D. D. UPADHYAYA
Pages : 119-123
DOI : 10.1080/0371750X.1996.10804768
Abstract
Formation of zirconia-tO mol% yttria coating on zircaloy
by the dip coating technique using sol-gel method was
studied. A hydrosol of zirconia was prepared by the thermal
hydrolysis of aqueous zirconium oxychloride followed
by coagulation-peptisation in water. The zircaloy substrate
was cleaned using S%HF-45%HN03-SO%H20 solution and
coated with the zirconia sol containing required amount of
·yttrium nitrate. Characterisation by XRD and IR spectra
studies of the dried gel and that heated to 250°C showed
the presence of capillary water and monoclinic phase.
Heating to 600°C results in formation of solid solution of
cubic zirconia-yttria. Morphological characterisation by·
SEM showed that crack free, fine grained and smooth
films of thickness about one micron can be prepared by
repeated coating with a sol of 0.1 M zirconia (1.2 wt%) and
a rate of withdrawal of 0.5 em per minute.