Percolation of Fibrous and Bimodal Fillers in Thermoreversible Gelcast Aluminum Oxide

A novel pore morphology was developed by addition of fugitive fibers to a thermoreversible gel slurry to induce pores in alumina (Al2 O3 ) samples.Through density measurements by the Archimedes’ method and SEM images the percolation threshold for fibers with aspect ratios of 37 and 120 was found to be less than 1 vol% fibers.Introducing two spherical fillers with different diameters (3.5:1 diameter ratio) to create bimodal filler has a small effect on the percolation threshold, if any.More research is needed to understand the effect of bimodal fillers on the pore morphology.