Rheological characterisation of Al 2 O 3 slips for aqueous low pressure injection moulding

Abstract

Near net shaping processes are receiving increased attention for manufacturing low cost, reliable ceramics. Low pressure injection moulding (LPIM) is a suitable forming procedure that allows the production of complex shaped parts by using aqueous suspensions, with interesting economic and environmental benefits. In the present work, aqueous Al₂O₃ slips were prepared and characterised for LPIM, focusing on their rheological properties not only at room temperature, but also at the injection temperatures (up to 70°C), as well as on the influence of the homogenisation procedure. Agarose (1 wt-%) was added as gelating binder. Injection was performed at temperatures of 55, 60, and 70°C, and the resulting green pieces were characterised in terms of density, shrinkage, and microstructure.