The development of robust thermal barrier coating (TBC) systems is crucial in many high-temperature applications. The performance of a TBC system is significantly limited by microstructural evolution mechanisms, such as sintering at elevated temperatures. Sintering reduces the porosity of TBC and makes it denser which eventually increases the thermal conductivity and reduces the strain compliance of TBC. Understanding how sintering proceeds in TBC systems is thus important in improving the design of such systems. An elaborate phase field model was developed in order to understand the sintering behavior of columnar TBC structure. The model takes into account different sintering mechanisms, such as volume diffusion, grain boundary diffusion, surface diffusion, and grain boundary migration, coupled with elastic strain arising from the thermal expansion mismatch in thermal barrier coating system. Direct relations between model parameters and material properties were established. Such relations facilitate quantitative studies of the sintering process in any material of interest. The model successfully demonstrates a strong dependence of the sintering process in TBC on the initial morphology and dimensions of coatings, strain, and temperature. / A Thesis submitted to the Graduate School in partial fulfillment of the requirements for the degree of Master of Science. / Fall Semester, 2011. / October 27, 2011. / Microstructure Evolution, Phase Field Model, Sintering, Thermal Barrier Coatings / Includes bibliographical references. / Anter El-Azab, Professor Directing Thesis; Anke Meyer-Baese, Committee Member; Sachin Shanbhag, Committee Member; Xiaoqiang Wang, Committee Member.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_182744 |
| Contributors | Ahmed, Karim (authoraut), El-Azab, Anter (professor directing thesis), Meyer-Baese, Anke (committee member), Shanbhag, Sachin (committee member), Wang, Xiaoqiang (committee member), Program in Materials Science (degree granting department), Florida State University (degree granting institution) |
| Publisher | Florida State University, Florida State University |
| Source Sets | Florida State University |
| Language | English, English |
| Detected Language | English |
| Type | Text, text |
| Format | 1 online resource, computer, application/pdf |
| Rights | This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s). The copyright in theses and dissertations completed at Florida State University is held by the students who author them. |
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