High Temperature Fatigue in Ceramic Wall-Flow Diesel Filters

Under certain operating conditions when the combined stresses in a ceramic wall-flow diesel filter from mechanical, thermal, and vibrational loads exceed its threshold strength, the fatigue effects become important. This paper reviews the theory of static and dynamic fatigue, and presents fatigue data for Coming's high efficiency filter composition (EX-47, 100/17) in the temperature range 25° - 400°C which is representative of the stressed peripheral region during regeneration. The measurement and analysis of fatigue data, together with the implication on long-term durability of cordierite ceramic filters, is discussed.