Zirconia Calcia solid solution formation by high energy milling of pure oxides; influence of Calcia content.

G. SUAREZ; N. RENDTORFF; E. AGLIETTI

La Plata

Conferencia; HK 2010 - Humboldt Kolleg; 2011

IFLP (CONICET), UNLP

There are several applications of zirconia ceramics as a structure material or solid electrolyte; the polymorphic variety thermodynamically stable at room temperature is the monoclinic zirconia (m-ZrO2). It is well known that by adding cations in the structure of zirconia can be fully or partially stabilized in cubic (c-ZrO2) or tetragonal (t-ZrO2) forms. These structures present different (better) mechanical and electrical properties. Stabilized zirconia can be achieved by chemical stabilization or by heating treatment. In this second case the high temperatures (≥ 1100 º C) is responsible for the cation inter diffusion in the zirconia matrix. 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 establish the influence of the CaO proportion (3%, 8% and 13% molar) in the ZrO2-Ca+2 solid solution formation by High energy milling of pure oxides mixtures. 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.