Porosity control in silicon nitride‐based support materials toward enhanced gas permeability

Abstract Porous Si 3 N 4 materials in tubular geometry are prepared by slip casting before partial sintering. A variety of material‐ and process‐specific variables their respective effects on densification resulting pore morphology systematically evaluated, focusing starting powder type, amount sintering additives, parameters including temperature time. An increased β ‐Si content the was found to promote formation a network elongated grains exhibiting diameters, as opposed more finely featured obtained from consisting α . Following an iterative evaluation processing variables, characteristic diametral compression strength (C‐ring test) 163 MPa Darcian permeability 4.7 ⋅ 10 −15 m 2 at total porosity 41% were obtained, corresponding increase over 40% 600% comparison powders comparable porosities. These results demonstrate that composition significantly affects structure, combining selection with tuned parameters, superior performance terms mechanical properties well characteristics accessible.