Development of a Synthetic Volcanic Ash Test Media
Date of Award
5-5-2024
Degree Name
M.S. in Materials Engineering
Department
Department of Chemical and Materials Engineering
Advisor/Chair
Li Cao
Abstract
If gone undetected, volcanic ash in the atmosphere can have significant negative effects on the performance of air-breathing gas turbine engines. When ingested into the front of the engine, abrasion and erosion of key mechanical components can occur, accompanied by degradation of the materials located in the late-stages of the engine by ash that has become molten due to the high-temperature environment. These phenomena can lead to significant damage and premature failure in a fielded gas-turbine engine, thus the need to evaluate engine materials prior to their implementation arises. While volcanic ashes and turbine engine materials have been studied extensively in the literature, they have largely been studied independently, therefore no standardized volcanic ash media to be used in materials testing has been developed. In this work, a group of natural volcanic ash samples were evaluated using a variety of techniques to understand their chemical, physical, and thermal behavior. The information gathered in the characterization of the group of natural ash samples was then used to develop a synthetic volcanic ash media that has similar chemistry to and behaves like a natural ash when exposed to an environment like that in a late-stage gas turbine engine. The new synthetic ash media was compared to a natural ash, from Mt. Mazama in Oregon, USA. Specifically, its ability to melt and infiltrate the microstructural features of 7% yttria-stabilized zirconia thermal barrier coatings deposited on superalloy coupons was examined. It was shown via SEM analysis that when heated to 1200 °C, the synthetic ash melts and infiltrates the thermal barrier coating within a comparable time (<30 minutes) as Mt. Mazama ash, leading to the conclusion that it can be deemed an effective replacement for natural volcanic ash in materials testing. The development of this synthetic ash test media is meant to provide a solid starting point for future development of medias used to test and screen turbine engine materials that are standardized and more readily available than natural volcanic ash currently is.
Keywords
Materials Engineering, Volcanology, Mineralogy, Thermal Barrier Coatings, YSZ, Gas Turbine Engines, CMAS
Rights Statement
Copyright 2024, author
Recommended Citation
Lanham, Spencer B., "Development of a Synthetic Volcanic Ash Test Media" (2024). Graduate Theses and Dissertations. 7592.
https://ecommons.udayton.edu/graduate_theses/7592
