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Cordierite has been the cost-effective material of choice for diesel particulate filters (DPFs) for heavy duty vehicles due to its combination of excellent thermal shock resistance, filtration efficiency, and durability under most operating conditions. However, it has been observed that under some conditions of uncontrolled regeneration at moderately high soot loading, localized regions of melting in cordierite DPF bodies can occur. A new cordierite monolithic diesel particulate filter has been developed for medium and heavy duty trucks for OEM and retrofit applications. Through modification in pore microstructure and filter cell geometry, this new DPF provides improved survivability during uncontrolled regenerations, reduced pressure drop, and improved thermal shock resistance and strength.

Cordierite-based diesel particulate filters (DPFs) have been in use for heavy duty engine applications for nearly two decades. Recently, passenger car applications for DPFs have begun to appear in Europe due to tightening legislation. While cordierite-based DPFs work well in most applications, it appears that in the passenger car exhaust environment under some uncontrolled regeneration conditions, cracking and melting of the existing cordierite-based DPF products have been reported. The present paper focuses on the development of new, high temperature oxide ceramics for DPF passenger car applications. When designed properly, DPFs made from these new materials do not show cracking or melting under uncontrolled regeneration. The material properties (strength, elastic modulus, coefficient of thermal expansion, etc.) and the filter performance properties (pressure drop, regeneration durability, etc.) have been characterized for DPFs made from these new materials.