Structure formation and degradation of partially stabilized zirconium dioxide

The process of structure formation of partially stabilized zirconium dioxid e powders during the heat treatment of precipitated zirconium and yttrium h ydroxides and structure degradation in time depending on hydroxide precipit ation method (mutual and sequential precipitation) has been investigated. D uring calcination, the t-->m-ZrO2 transition takes place in sequentially pr ecipitated hydroxides, and the m-->t-ZrO2 transition takes place in copreci pitated hydroxides. It was noted that soft readily, destroyable aggregates are formed during the hear treatment of sequentially precipitated hydroxide s. This makes it possible to produce fine ZrO2 powders (d = 50-100 nm) avoi ding disaggregation and/or milling. It has been found that the zirconium di oxide degradation process, which is due to the t-->m-ZrO2 transformation, d ecreases with increasing amount of Y2O3 and cubic modification of ZrO2 in h eat treatment products and in the case of coprecipitation of hydroxides (C) 1999 Elsevier Science Limited. All rights reserved.