Densification characteristics of ZrO2 doped pure AI2O3 ceramics synthesized through co-precipitation route

Department of Chemical Technology, Ceramic Engineering Division, University of Calcutta, 92, Acharya Prafulla Chandra Road, Kolkata-700 009, India E-mail: mailme.tapan@gmail.com Fax : 91-33-2351975_5 Manuscript received online 26 June 2012, revised 17 July 2012, accepted 07 August 2012 In this study, the co-precipitated hydroxides hydrogels of aluminium and zirconium containing :very small proportion of ZrO2 varying from 0-0.3% (w/w) only have been synthesized by wet chemical interaction. of requisite quantity of 0.2 M solution of aluminium isopropoxide and zirconium oxychloride dissolved in 1 : 1 isopropanol-water mixture at pH value from 3.5-4.0 under reflux at 80 °C. The double hydroxides gel precursor of aluminium and zirconium are characterized by specific surface area, DTA, FTIR studies. Zirconia toughened sintered pure alumina body with significant improvement of thermo mechanical properties and fine grained homogeneous microstructure is accomplished via solid state sintering of the co-precipitated hydroxides hydrogel of aluminium doped with ZrO2 (0.2% w/w) at the temperature of 1550 °C. The secondary electron images of fired alumina compacts reveal that in situ formed nanozirconia in minor amount is observed to act as grain growth inhibitor for alumina system and augments the formation zirconia toughened coherent Al2O3 ceramics