화학공학소재연구정보센터
Journal of the American Ceramic Society, Vol.98, No.8, 2366-2372, 2015
Stabilization of Nanoalumina Colloidal Slips
The processing of nanosized powders to produce dense components is a difficult task, mainly due to the strong agglomeration of nanoparticles. In this work, deagglomeration studies were carried out on sol-gel-derived -alumina suspensions through the addition of dispersant or dispersant in combination with ethylene glycol as binder and the proper wet ball-milling. For this purpose, zeta-potential, viscosity, and sedimentation studies were carried out, whereas dilatometric studies accompanied by XRD analyses were performed on the powders derived from the most stable suspensions. Sintering studies followed and the as received ceramics were evaluated by SEM. The optimum stabilization was achieved through the synergistic addition of 2.75mg/g ammonium polymethacrylate with 1wt% ethylene glycol. The respective powder, although it indicates a shift of the sintering start to higher temperature, leads to the densest ceramic with the finest (500nm mean grain size) and the most homogeneous microstructure.