Production and permeability of porous Si 3 N 4 ceramics produced by starch addition

•We produce highly porous (up to 66%) Si3N4.•We enhance the permeability of Si3N4 by using starch as pore former.•Increasing starch amount (≥20vol.%) created large and bimodal pore channels and permeability values of these samples are quite higher.•Pore size is more predominant than porosity on permeability.