Download the full-sized PDF
Permanent link (DOI): https://doi.org/10.7939/R39613
This file is in the following communities:
|Graduate Studies and Research, Faculty of|
This file is in the following collections:
|Theses and Dissertations|
Protective/Conductive Coatings for Ferritic Stainless Steel Interconnects Used in Solid Oxide Fuel Cells Open Access
- Other title
Ferritic Stainless Steels
Reactive Element Effect
Solid Oxide Fuel Cells
- Type of item
- Degree grantor
University of Alberta
- Author or creator
- Supervisor and department
Dr. Douglas G. Ivey, ( Department of Chemical and Materials Engineering)
Dr. Weixing Chen, (Department of Chemical and Materials Engineering)
- Examining committee member and department
Dr. Anthony Petric, (McMaster University)
Dr. Andre McDonald, (Department of Mechanical Engineering)
Dr. Qi Liu, (Department of Chemical and Materials Engineering)
Dr. John Nychka, (Department of Chemical and Materials Engineering)
Department of Chemical and Materials Engineering
- Date accepted
- Graduation date
Doctor of Philosophy
- Degree level
Ferritic stainless steels are the most commonly used materials for solid oxide fuel cell interconnect application. Although these alloys may meet the criteria for interconnect application for short periods of service, their application is limited for long-term use (i.e., 40,000 h) due to poor oxidation behaviour that results in a rapid increase in contact resistance. In addition, volatile Cr species migrating from the chromia scale can poison the cathode resulting in a considerable drop in performance of the cell. Coatings and surface modifications have been developed in order to mitigate the abovementioned problems.
In this study, composite electrodeposition of reactive element containing particles in a metal matrix was considered as a solution to the interconnect problems. Nickel and Co were used as the metal matrix and LaCrO3 particles as the reactive element containing particles. The role of the particles was to improve the oxidation resistance and oxide scale adhesion, while the role of Ni or Co was to provide a matrix for embedding of the particles. Also, oxidation of the Ni or Co matrix led to the formation of conductive oxides. Moreover, as another part of this study, the effect of substrate composition on performance of steel interconnects was investigated.
Numerous experimental techniques were used to study and characterise the oxidation behaviour of the composite coatings, as well as the metal-oxide scale interface properties. Scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDX), as well as surface analysis techniques including Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS) and secondary ion mass spectroscopy (SIMS), were used for the purpose of characterization. The substrate used for coating was AISI-SAE 430 stainless steel that is considered as a typical, formerly used interconnect material. Also, for the purpose of the metal-oxide scale interfacial study, ZMG232 stainless steel that is a specially designed interconnect alloy was used.
It is shown that the composite coatings greatly reduce the contact resistance and effectively inhibit Cr outward migration. In addition, it was determined that the presence of impurities in the steel, especially Si, and the absence of reactive elements drastically contribute to interconnect degradation.
- Permission is hereby granted to the University of Alberta Libraries to reproduce single copies of this thesis and to lend or sell such copies for private, scholarly or scientific research purposes only. Where the thesis is converted to, or otherwise made available in digital form, the University of Alberta will advise potential users of the thesis of these terms. The author reserves all other publication and other rights in association with the copyright in the thesis and, except as herein before provided, neither the thesis nor any substantial portion thereof may be printed or otherwise reproduced in any material form whatsoever without the author's prior written permission.
- Citation for previous publication
- Date Uploaded
- Date Modified
- Audit Status
- Audits have not yet been run on this file.
File format: pdf (Portable Document Format)
Mime type: application/pdf
File size: 9848519
Last modified: 2015:10:12 18:30:55-06:00
Filename: Shaigan_Nima_Fall 2009.pdf
Original checksum: c361cf2422ff526054e0277bd879fdf1
Well formed: true
File title: 1 Introduction and Literature review
File title: 1
File author: Nima Shaigan
Page count: 173