Abstract
Manufacturing honeycomb-structured catalysts require a careful understanding of the microstructure of the solid substrate and its dependence on thermal-processing conditions. Herein, it is the thermal responses of microcracks in an uncoated microcracked aluminum titanate honeycomb catalyst is investigated by analyzing the material's resonance frequency using the high-temperature impulse excitation technique. The resonance frequencies are presented as Young's modulus values to avoid sample size effects. Dynamic Young's modulus measurements show closed-loop hysteresis due to microcracks healing and reopening, causing a reversible response. The hysteresis is further used to understand microcracks’ dependence on critical thermal-processing conditions used in a catalyst manufacturing plant, including peak operating temperature (800–1000 °C), dwell period (1–3 h), and heating rates (1–5 °C min−1). Microcracks are observed to have two healing responses: instantaneous and delayed healing. Both responses significantly influence the design of catalyst manufacturing. Complete reopening of microcracks from their healing temperature (1150 °C) is a very time-consuming process (50–60 h). However, it is shown in the analysis that microcrack relaxation is a critical phenomenon that must be considered in quality-controlled environments.
Original language | English |
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Article number | 2201766 |
Number of pages | 10 |
Journal | Advanced Engineering Materials |
Early online date | 24 Mar 2023 |
DOIs | |
Publication status | Published - 5 Apr 2023 |
Bibliographical note
Funding Information:S.N. is funded by the EPSRC Centre for Doctoral Training in Formulation Engineering at the University of Birmingham (EP/S023070/1) and Johnson Matthey. The authors thank and appreciate the continuous support and feedback from Raymond Hadden (Johnson Matthey) and Katarzyna Piskorz (Johnson Matthey), who actively participated in the discussions of this study.
Publisher Copyright:
© 2023 Wiley-VCH GmbH.
Keywords
- catalyst manufacturing
- honeycombs
- impulse excitation
- microcracks
- Young's modulus
ASJC Scopus subject areas
- General Materials Science
- Condensed Matter Physics