Florida International University FIU Digital Commons FIU Electronic Theses and Dissertations University Graduate School 6-26-2020 Boron Nitride Nanotube based Lightweight Metal Matrix Composites: Microstructure Engineering and Stress-Transfer Mechanics Pranjal Nautiyal Florida International University, [email protected] Follow this and additional works at: https://digitalcommons.fiu.edu/etd Part of the Manufacturing Commons, Metallurgy Commons, and the Structural Materials Commons Recommended Citation Nautiyal, Pranjal, "Boron Nitride Nanotube based Lightweight Metal Matrix Composites: Microstructure Engineering and Stress-Transfer Mechanics" (2020). FIU Electronic Theses and Dissertations. 4513. https://digitalcommons.fiu.edu/etd/4513 This work is brought to you for free and open access by the University Graduate School at FIU Digital Commons. It has been accepted for inclusion in FIU Electronic Theses and Dissertations by an authorized administrator of FIU Digital Commons. For more information, please contact [email protected]. FLORIDA INTERNATIONAL UNIVERSITY Miami, Florida BORON NITRIDE NANOTUBE BASED LIGHTWEIGHT METAL MATRIX COMPOSITES: MICROSTRUCTURE ENGINEERING AND STRESS-TRANSFER MECHANICS A dissertation submitted in partial fulfillment of the requirements for the degree of D OCTOR OF PH ILOSOPHY in MATERIALS SCIENCE AND ENGINEERING by Pranjal N autiyal 2020 To: Dean John L. Volakis College of Engineering and Computing This dissertation, written by Pranjal Nautiyal, and entitled Boron Nitride Nanotube based Lightweight Metal Matrix Composites: Microstructure Engineering and Stress-Transfer Mechanics, having been approved in respect to style and intellectual content, is referred to you for judgment. We have read this dissertation and recommend that it be approved. _____________________________________________ Zhe Cheng _____________________________________________ Seung Jae Lee _____________________________________________ Benjamin Boesl, Co-Major Professor _____________________________________________ Arvind Agarwal, Co-Major Professor Date of Defense: June 26, 2020 The dissertation of Pranjal Nautiyal is approved. _____________________________________________ Dean John L. Volakis College of Engineering and Computing _____________________________________________ Andrés G. Gill Vice President for Research and Economic Development and Dean of the University Graduate School Florida International University, 2020 ii © Copyright 2020 by Pranjal Nautiyal All rights reserved. iii DEDICATION I dedicate this dissertation to my parents, family, teachers and mentors, who have shaped me into the person I am today. iv ACKNOWLDGMENTS I want to express my sincere gratitude to my major professor, Dr. Arvind Agarwal, for playing a critical role in the planning, execution and conclusion of this research. I had the privilege of working with Prof. Agarwal as an undergraduate researcher first, and my decision to pursue Ph.D. was based on his encouragement and support. When I look back, that was the best decision I have taken in my life so far. I cannot thank Prof. Agarwal enough for the countless hours he has spent reviewing my progress, scrutinizing my results, providing timely feedback and making sure my work is rapidly published. I am grateful for all the opportunities he has provided me to excel professionally, including access to cutting edge research facilities, opportunities to present my work in numerous international forums, opportunity to write a book, participate in proposal writing activities, and collaborations with world-class researchers on brilliant research projects. Beyond a mentor, Dr. Agarwal is a cheerleader who pushes me to perform better every single day and he lifts me up every time I hit obstacles or face disappointments. I want to thank my co-advisor, Dr. Benjamin Boesl, for facilitating the successful completion of my Ph.D. project through his guidance and expertise on the mechanics of composites. Dr. Boesl mentored me as I grasped and worked in the area of in-situ mechanical characterization, which has become a centerpiece of my research activities over the last 4 years. Dr. Boesl was kind and patient to spend time with me in the laboratory, providing feedback with my experimental plans and reviewing the manuscripts published out of this dissertation project. In the last 5 years, we have forged a pleasant and productive professional relationship. v I sincerely thank Drs. Seung Jae Lee and Zhe Cheng for serving in my committee. Their yearly feedback on my research was helpful to ensure I meet my dissertation objectives in a timely manner. I’m grateful for their time, efforts, and responsiveness. I have collaborated with several of my colleagues in the Plasma Forming Group. I would like to acknowledge Dr. Archana Loganathan, Dr. Cheng Zhang, Dr. Chris Rudolf, Jenniffer Bustillos, Xiaolong Lu, Noemie Denis, and Tyler Dolmetsch. Their contributions were instrumental in meeting many of the key dissertation objectives and publication of several journal articles related to this project. I gained valuable knowledge and insights working with them. A significant portion of my research is carried out in the Advanced Materials Engineering Research Institute (AMERI) at FIU. I would like to particularly thank Dr. Alex Franco, an AMERI staff and research assistant professor, for spending long days training me, aiding in electron microscope characterizations and facilitating equipment troubleshooting. Some of the central segments of my research would not have been completed without Dr. Franco’s assistance. I would also like to acknowledge former AMERI staff members, Drs. Yusuf Emirov and Shravana Katakam, for their assistance with focused ion beam machining and transmission electron microscopy. I would like to mention the outstanding contributions from our collaborators at the University of Central Florida, Prof. Sudipta Seal, Dr. Tamil S. Sakthivel and Dr. Ankur Gupta (now with Persimmon Technologies Corporation), who carried out high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy of nanocomposite specimens. Their expertise was helpful in deciphering the complex microstructures of the vi composites studied herein. I also thank Prof. Chunlei Wang (in my department) and Dr. Richa Agrawal (a former FIU graduate student) for assisting us with Fourier transform infrared spectroscopy. I would like to acknowledge the financial support received from FIU Graduate School through the Presidential Fellowship and Dissertation Year Fellowship awards. I also thank the Office of Naval Research grant (N00014-17-12563), the Army Research Laboratory grant (W911NF15-2-0026), and the National Science Foundation-Engineering Research Centers Program (CELL-MET ERC, NSF Cooperative Agreement No. EEC- 1647837) for research assistantship support and funding research supplies used to carry out the experiments. I’m thankful to Dr. Roy Whitney of BNNT, LLC. for providing nanotube samples useful to meet some of the central dissertation objectives. BNNT, LLC. is our trusted source of high-quality nanotubes, which is fundamental to the success of this project. I also express my gratitude to the current and former staff members of the Mechanical and Materials Engineering and AMERI for their assistance with logistics and administrative matters. I would like to mention Mabel Fernandez, Tiziana Leoni, and Beatriz Morillo, who would go out of their way to provide the best possible assistance with my assistantship contracts, research purchases, and work-related travels. No man is an island, and I’m highly a ppreciative of all m y current and former colleagues in the Plasma Forming Group for their support and encouragement. I have developed profound friendships in the last 5 years at FIU. I wish to thank Leslie Embrey, Melania Antillon, Archana Loganthan, Richa Agrawal, Tony Thomas, Jenniffer Bustillos, vii Cheng Zhang, Kazue Orisaka, Laura Reyes, Sadhana Bhusal, Luiza Fontoura, Tanaji Paul, Giuseppe Bianco, Cat Young and Sadegh Behdad for some of the fondest memories. Leslie and Richa have become my family in the United States, and I treasure their friendship. Most importantly, I express my deepest gratitude to my loving family: my parents, my aunts and uncles, my siblings, and my grandparents. I derive my humanity and strength of character from them. My father, in particular, is a role model for me, and I always strive to emulate him in leading my life with integrity, courage, and conviction. viii ABSTRACT OF THE DISSERTATION BORON NITRIDE NANOTUBE BASED LIGHTWEIGHT METAL MATRIX COMPO SITES: MICROSTRUCTURE ENGINEERING AND STRESS-TRANSFER MECHANICS by Pranjal Nautiyal Florida International University, 2020 Miami, Florida Professor Arvind Agarwal, Co-Major Professor Professor Benjamin Boesl, Co-Major Professor Lightweight metals, such as Aluminum, Magnesium and Titanium, are receiving widespread attention for manufacturing agile structures. However, the mechanical strength of these metals and their alloys fall short of structural steels, curtailing their applicability in engineering applications where superior load-bearing ability is required. There is a need to effectively augment the deformation- and failure-resistance of these metals without compromising their density advantage. This dissertation explores the mechanical reinforcement of the aforementioned lightweight metal matrices by utilizing Boron Nitride Nanotube (BNNT), a 1D nanomaterial with extraordinary mechanical properties. The nanotubes are found to resist thermo-oxidative