Dense m-Li2ZrO3 formed by aqueous slip casting technique: Colloidal and rheological characterization

Abstract

An aqueous colloidal processing method was proposed to prepare m-Li2ZrO3 bodies, with high green density and a homogenous microstructure, employing a pressureless forming technique. For this purpose, the preparation conditions of m-Li2ZrO3 aqueous suspensions were optimized considering colloidal processing variables, such as milling time (0?40 min), dispersant concentration (1?10 wt% of the solids content) and maximum solid loading (41?74 wt%). Particle size distributions and steady-state flow curves of the slips were analyzed, together with phase composition and microstructure of the ceramic bodies. The results show that after planetary ball milling for 30 min, the aqueous suspension with 63.1 wt% of m-Li2ZrO3, and a dispersant content equal to 10 wt% of the solid loading, yielded green bodies with bulk densities close to 66% TD by slip casting. Then, after the heat treatment process at 1100 °C for 12 h, bulk densities close to 88% TD were achieved. It was found that density values and microstructure of the green and sintered products bear a direct relationship to the particle size and the consistency of the slips.