Production of porous SiC based composites for diesel particle filter applications

Motor vehicles have a significant share in air pollution. This handicap necessitates the development of emission control technologies. The most important of the pollutants in the exhaust gas resulting from combustion in internal combustion diesel engines; Particulate Matter (PM), Nitrogen Oxides, Hydrocarbons and Carbon Monoxide. Diesel particulate filters (DPF); particulate is one of the most technically feasible solutions used to reduce emissions. In the Master of Science study; SiC (Silicon Carbide) Based Composite production, which can be an alternative to existing Diesel Particulate Filters (DPF) used in the commercial area, to improve the performance of the filter and to improve the engine performance; microstructure - property - pressure difference triangle was investigated and production of the wall structure which could be considered as the unit element of DPF in laboratory scale was realized. There is no previous study in the literature on the development of acicular grains to improve the performance of commercial SiC DPFs. From this point of view, in order to gain original and innovative direction of the study, original chemical compositions are developed in the wall pore structure of DPF to form needle-like grains. The SiC based composite structure DPF wall, which was produced after the study, was tested for pressure differences and compared with the permeability properties of current commercial SiC DPFs. However; open porosity ratio determination, bulk density measurement, post-baking weight change determination, SEM microstructure analysis, EDX elemental analysis, phase analysis with XRD and pore size and size distribution with mercury porosimetry were analyzed. As a result of the studies, composite material with ~1.4 m length, ~0.2 m diameter Si3N4 spindle grains, %49,37 open porosity mean, 5,03 m average pore size, mean 6.57.10-14 m2 darcy permeability developed. In comparison; the characteristics of commercial SiC DPF have %50-60 open porosity, ~11-12 m average pore size and 3,91,10-12 m2 darcy permeability respectively. Keywords: Diesel Particulate Filter, Porous Ceramic, Silicon Carbide, Composite, Permeability