Thomas Nagel

A new approach of accelerated life testing for metallic catalytic converters

The Environmental Protection Agency (EPA) and California Air Resources Board (CARB) requirements for high mileage durability of emission components make it necessary to ensure the mechanical robustness of metallic catalytic converters. In addition, the robustness of design features must be assessed in the early design development phase without resorting to vehicle fleet testing. By following established reliability methods, a new approach for time and cost efficient accelerated durability testing was developed, which can account for the combined effects of critical stressors of a metallic catalytic converter. This paper describes the methodology used to determine the critical stressors and their levels in actual operating conditions which were determined by analyzing a broad range of vehicle test information. This information was used to develop a temperature profile and a high vibration load profile for the new life test method. Finally, this paper describes the combination and superimposed introduction of all stressors in a hot vibration/ thermal cycling component bench test. The new time and cost efficient highly accelerated test method can reproduce metallic converter failure modes and can be used to develop the robustness of mechanical designs for metallic catalytic converters.