Consolidation of complex-shape zircon compacts through agar gelation

Zirconium silicate (zircon, ZrSiO4) is a ceramic material with excellent thermal properties, such as low conductivity and high shock resistance. In this work, dense zircon complex shaped parts were obtained by aqueous gelcasting through agar gelation. The colloidal stability study was performed zeta potential measurements function of pH polyacrylic-based deflocculant concentration (PAA). rheological carried out varying the solids content, dispersant concentration, sonication mixing time, best results being for 0.1 wt.% PAA 1 min sonication. viscosity versus temperature curves recorded on cooling zircon-agar mixtures showing gelling approximately 35 °C. Better performance achieved suspensions prepared at loading 40 vol.%. Dynamic sintering (25–1550 °C) isothermal tests (1550 °C 1600 out, studying shrinkage densification material. Finally, evolution phases microstructure sintered studied using X-ray diffraction (XRD) scanning electron microscopy (SEM). Relative densities 94.5% TD reached °C/2 h, but increased to 96% 8 h holding, small grain size increase from 1.8 2.4 µm.