Comparison of corrosion resistance of cordierite and silicon carbide diesel particulate filters to combustion products of diesel fuel containing FE and CE additives

Cordierite porous honeycomb structures have been used successfully as participate filters in heavy duty diesel engine applications for nearly two decades. However, some cracking and melting of cordierite based products have been reported under some uncontrolled regeneration conditions in passenger car exhaust systems. As a result silicon carbide based diesel particulate filters have emerged in recent years for application in passenger cars, particularly in Europe. The present paper describes a series of experiments to investigate chemical interactions between cordierite or silicon carbide filter substrate materials and synthetic ash compositions expected to be deposited on the surfaces of the ceramic filter and within its pore structure as a result of the combustion of diesel fuel containing catalytic additives. Analysis of the experimental data allows prediction of the behaviour of filters under regeneration conditions and sets upper temperature limits to be defined for effective use of the two filter materials.