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

•We produce highly porous (up to 66%) Si ₃ N ₄ .•We enhance the permeability of Si ₃ N ₄ 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. In this study, the possibility of enhancing permeability of porous Si ₃ N ₄ ceramics was studied by using pore former additive (potato starch; 0-30vol.%). The open porosity of samples changed between 52 and 66% as the mean pore channel size values ranged from 0.9 to 4μm. Increasing starch addition provides bimodal distribution of pore size channels by accompanying abrupt increment in non-Darcian permeability. k ₂ value rised from 8.7×10 ^-10 m to 30.1×10 ^-10 m.