Development of si3n4 based materials for diesel particulate filter (DPF) production

Studies that have been carried out to fulfill the increasing expectations from diesel particulate filter materials have been focused on finding new materials and tailoring filter?s structure. In this PhD study, processing of Si3N4 that can be the alternative of commercial ceramic diesel particulate filters was investigated by considering structure-property-performance relationship. Therefore, porous Si3N4 with different microstructures were produced and pressure loss, permeability and soot loading behavior of these materials were investigated.Studies showed that performance behaviors of diesel particulate filters were affected by pore size and microstructure rather than the porosity of the material. As k1 permeability value of produced Si3N4 materials with a traditional microstructure was 7.9x10-14 m2, it?s possible to enhance this value to a degree of 20.4x10-14 m2 by obtaining coarse and equiaxed grains in microstructure. In spite of their low permeability, traditional Si3N4 have a high particle filtration capacity. Due to this property, usage of Si3N4 as a coating material for membrane diesel particulate filter application beside filter material was demonstrated by this study.Key Words: Diesel particulate filter, Porous Si3N4, Microstructure, Permeability, Soot loading