Committee Chair

Mahtabi Oghani, Mohammad Javad, 1982-

Committee Member

Ibrahim, Hamdy; Margraves, Charles H.

Department

Dept. of Mechanical Engineering

College

College of Engineering and Computer Science

Publisher

University of Tennessee at Chattanooga

Place of Publication

Chattanooga (Tenn.)

Abstract

Magnesium alloys represent a promising alternative to conventional implant materials due to their mechanical properties and biodegradability. However, Mg suffers from rapid corrosion in physiological environments. Plasma electrolytic oxidation (PEO) coating was shown to improve corrosion resistance but it introduces pores and microcracks that compromise fatigue performance. Therefore, this study investigates the effect of sealing those surface defects by applying layers of sol-gel thin films on the fatigue resistance of AZ31B Mg alloy. Fatigue tests were conducted on both non-corroded and pre-corroded bare (non-coated), PEO-coated and hybrid-coated (PEO and sol-gel) Mg alloy samples. Results indicated distinct fatigue behavior pre-corroded and non-corroded samples. Both the non-corroded coated groups exhibited shorter fatigue lives under high cycle fatigue conditions, with minimal differences observed between coated and bare groups under low cycle fatigue. On the other hand, pre-corroded coated groups showed infinite life under high cycle fatigue, with insignificant differences under low cycle fatigue.

Acknowledgments

I would like to express my sincere gratitude to my supervisors, Dr. Mohammad Mahtabi and Dr. Hamdy Ibrahim. Their guidance and support were crucial in shaping and completing this project. I would also like to extend my thanks to my committee member, Dr. Charles Margraves, for his time and participation. Furthermore, I am immensely grateful for the support of the Mechanical Engineering Department at UTC. Without it, this research wouldn’t have been possible. My thanks also go to my colleague, George Thompson, for assisting me with equipment training and my thesis revision. Last but not least, I express my deepest gratitude to my family and friends for their support and encouragement that have provided me with strength in this journey.

Degree

M. S.; A thesis submitted to the faculty of the University of Tennessee at Chattanooga in partial fulfillment of the requirements of the degree of Master of Science.

Date

8-2026

Subject

Biomedical materials; Fatigue of metals; Magnesium alloys--Corrosion

Keyword

magnesium; plasma electrolytic oxidation (PEO) coating; sol-gel; fatigue; biodegradable implant materials

Document Type

Masters theses

DCMI Type

Text

Extent

xix, 71 leaves

Language

English

Rights

http://rightsstatements.org/vocab/InC/1.0/

License

http://creativecommons.org/licenses/by/4.0/

Date Available

8-31-2028

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Available for download on Thursday, August 31, 2028

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