Preparation of porous YSZ ceramics by ball milling foaming-freeze drying process

Abstract

In order to simplify foaming process and control foam volume, porous YSZ ceramics were prepared by ball milling foaming method in a fixed volume tank. Isobam was added to increase the strength of green body, freeze-drying process was used to accelerate the solidification rate of foamed slurry, and porous YSZ ceramics with uniform porosity were obtained after sintering. The effects of solid content, foaming agent content and ball milling speed on porosity and compressive strength were studied. Compared with mechanical stirring foaming process, it was found that ball milling foaming method could effectively foam in the case of less slurry, and the sample had higher porosity, uniform bubbles and higher strength. Porous YSZ ceramics with porosity of 73–89% and compressive strength of 0.4–7.6 MPa could be prepared by the ball milling foaming-freeze drying process.