Study on Rheological Behavior of Alumina Ceramic Slurry for Direct Ink Writing Process

Colloidal processing of ceramic materials has been the focus of attention in recent decades for obtaining green body, especially for production using 3D printing technology. Several 3D printing techniques have been currently in function for fabrication of ceramics. Direct ink writing technique, a material extrusion based process which involves extruding concentrated ceramic suspension through a nozzle, is a promising method among all the 3D printing techniques due to its low cost, design freedom, and multifunctionality. The control of rheological properties of ceramic suspension is a highly challenging task to match the requirements for 3D Printing. The rheological behavior of ceramic suspension is greatly affected by particle size, particle shape, and choice of binders. This study aims at rheological analysis of suspension using different concentrations of binders and 3D printing of alumina ceramics. In this research, the rheological parameters such as viscosity, storage modulus, and loss modulus have been studied to determine feasibility for direct ink writing process. Microstructural characterization and surface roughness measurements was performed on printed samples. It is found that the suspension consisting of 65 wt.% solid loading and 0.1–1.5 wt.% ISOBAM content was suitable for printing showing structural stability.