Mechanochemical stabilization and sintering of nanocrystalline the (ZrO2)0.97 (Y203)0.03 solid solution from pure oxides

N. RENDTORFF; G. SUAREZ; YOSHIO SAKKA; E. AGLIETTI

IOP Conf. Series: Materials Science and Engineering

IOP

Lugar: Londres; Año: 2011 vol. 18 p. 62018 - 62018

1757-8981

The mechanochemical activation processing has proved to be an effective technique to enhance a solid-state reaction at relatively low temperatures. In such a process, the mechanical effects of milling, such as reduction of particle size and mixture homogenization, are accompanied by chemical effects, such as partial decomposition of salts or hydroxides resulting in very active reactants. The objective of the present work is to obtain (ZrO2)0.97(Y203)0.03 nanocrystalline tetragonal solid solution powders directly using a high energy milling on a mixture of the pure oxides. A second objective is to evaluate the efficiency of the processing proposed and to characterize both textural and structural evolution of the mixtures during the milling processes and throughout posterior low temperature treatments. The Textural and structural evolution were studied by XRD analysis, specific area measurements (BET) and SEM. Firstly a decrease of the crystallinity of the reactants was observed, followed by the disappearance of Y2O3 diffraction peaks and the partial appearance of the tetragonal phase at room temperature. The solid solution proportion was increased with the high energy milling time, obtaining complete stabilization of the tetragonal solid solution with long milling treatments (60 min).The obtained powders were uniaxially pressed and sintered at different temperatures (600-1400ºC); the influence of the milling time was correlated with the sinterization degree and final crystalline composition of the materials. Finally, fully stabilized nanocrystalline zirconia materials were obtained satisfactorily by the proposed method