Viscosity Study to Optimize a Slurry of Alumina Mixed with Hollow Microspheres

Bukhari, Syed Zaighum Abbas;Ha, Jang-Hoon;Lee, Jongman;Song, In-Hyuck

  • Received : 2015.08.07
  • Accepted : 2015.10.16
  • Published : 2015.11.30


Porous alumina ceramics are involved in many industrial applications due to the exceptional properties of these products. This study addresses the preparation of porous alumina ceramics using hollow microspheres as a pore-forming agent and slip casting as a green-body-forming technique. A uniform distribution of pores is a basic requirement of a porous material. This study investigates three different slurry systems, i.e., as-prepared alumina slurry, alumina slurry electrostatically dispersed by hydrochloric acid (HCl), and slurry dispersed by the commercial dispersant 'Darvan C-N'. At a low viscosity, the hollow microspheres in the slurry tend to float, which causes a non-uniform pore distribution. To avoid this phenomenon, the viscosity of the slurry was increased to the extent that the movement of hollow microspheres ceased in the slurry. As a result, a uniform pore distribution was achieved.


Porous materials;Alumina;Slip casting;Viscosity


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Supported by : Korea Institute of Materials Science (KIMS)