Morphology, physical, thermal and mechanical properties of the constitutive materials of diesel particulate filters

Abstract : From experience it is known that the durability of diesel particulate filters (DPFs) may be limited by the high transient thermomechanical stresses created during severe regeneration rather than by mechanical fatigue. This paper, first of a series dealing with the thermomechanical behavior of DPFs, focuses on the morphology and the properties of the constitutive materials, i.e. the filtering SiC and the grout. The filtering material shows isotropic distributions of the SiC grains and the pores. It is characterized by a marked stability of the mechanical and thermal properties in the explored temperature range (up to 1100 °C). The grout with higher porosity is prone to important thermal transformations with no further consequences on filtration and durability. Due to its low thermal conductivity compared to the filtering material, its essential function is the isolation of the SiC bars from each other.