Influence of Thermal Treatment on Zirconia Powder

Abstract

Zirconia powder in amorphous state was prepared by electrolytic deposition method (ELD) and then it was subjected to a thermal treatment according to a typical diagram. The structural changes in zirconia powder induced by thermal treatment have been pointed out by X-Ray diffraction (XRD), thermogravimetric analysis (TGA) and differential thermoanalysis (DTA) techniques. During thermal treatment, XRD patterns and DTA curves showed the presence of a mixture of two crystalline phases well-formed at approximately 400oC and a transformation of the type tetragonal-monoclinic (t→m) at approximately 600oC. In situ XRD study allowed establishing the growth kinetics of crystalline phases. Using experimental maximum intensities, H(hkl) and integral intensities, I(hkl), of XRD peaks, the volume fractions, Vm, and Vt, of m and t phases, respectively, present in a polymorphic mixture were calculated.