engleski

Preparation of slip cast composite Al2O3-ZrO2 ceramics

In this paper Al2O3-ZrO2 composite ceramics was prepared by slip casting forming method followed by a conventional sintering. Slip casting is a filtration process, in which a powder suspension – usually a water-based suspension – is poured into a plaster mould, which by its porosity creates capillary forces and removes liquid from the suspension (slip). In comparison with other technologies, slip casting is a relatively simple, low-cost and environmentally friendly process. A highly concentrated suspension, 70 wt. % of Al2O3-ZrO2 (with powder mixture composition of 90 % Al2O3 and 10 % ZrO2), which is adequate for slip casting into plaster moulds with a high stability, was prepared. Suspension was stabilized by addition of dispersant DOLAPIX CE 64. The stability of prepared suspension was investigated by rheological parameters determination by measuring apparent viscosity at different shear rates and used for defining flow curves. Prepared aqueous Al2O3-ZrO2 suspensions are characterized as non-Newtonian, which means their viscosity changes with the shear rate change. For mathematical description of these fluids, Power law, Herschel-Bulkley model and Bingham plastic model were used. After forming and sintering, morphology of obtained composite ceramics was analysed by SEM-EDS analysis.

Al2O3-ZrO2; slip casting; SEM-EDS

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