Development of Co-Ni-Ga Ferromagnetic Shape Memory Alloys (FSMAs) by Investigating the ...

188 Pages·2013·21.79 MB·English

UC Riverside
UC Riverside Electronic Theses and Dissertations
Title
Development of Co-Ni-Ga Ferromagnetic Shape Memory Alloys (FSMAs) by Investigating the
Effects of Solidification Processing Parameters
Permalink
https://escholarship.org/uc/item/4tj615d9
Author
Kalaantari, Haamun
Publication Date
2013

Peer reviewed|Thesis/dissertation
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University of California
UNIVERSITY OF CALIFORNIA
RIVERSIDE

Development of Co-Ni-Ga Ferromagnetic Shape Memory Alloys (FSMAs) by
Investigating the Effects of Solidification Processing Parameters

A Dissertation submitted in partial satisfaction
of the requirements for the degree of

Doctor of Philosophy

in

Mechanical Engineering

by

Haamun Kalaantari

March 2013

Dissertation Committee:
Professor Reza Abbaschian, Chairperson
Professor Cengiz Ozkan
Professor Javier Garay
Copyright by
Haamun Kalaantari
2013
The Dissertation of Haamun Kalaantari is approved:

Committee Chairperson

University of California, Riverside
Acknowledgments
I wish to take this opportunity and express my appreciation and respect to all of them
who made my journey unforgettable to this point.
First and the foremost, I am deeply indebted and thankful to my PhD advisor, Professor
Reza Abbaschian for all of his enlightening guidance, unreserved support, kindness,
generosity, motivation, enthusiasm and the confidence he gave me through each single
step of this journey. He taught me a lot through those numerous research and stimulating
discussions and provided me with constructive suggestions. His mentorship was
paramount in providing a well-rounded experience consistent with my long-term career
goals. I have been amazingly fortunate to have an advisor who gave me the freedom to
explore on my own, and at the same time the guidance to recover when my steps faltered.
His patience and support helped me overcome many crises and finish this dissertation. He
encouraged me to grow not only as an experimentalist but also as an instructor and an
independent thinker. I am not sure many graduate students are given the opportunity to
develop their own individuality and self-sufficiency by being allowed to work with such
independence. For everything you have done for me, Professor Abbaschian, I thank you.
My thanks also go to the members of my internal dissertation committee, Professor
Cengiz Ozkan and Professor Javier Garay for reading the research proposal and previous
drafts of this dissertation and providing valuable comments that improved the
presentation and contents of this dissertation.
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I would like to thank Dr. Abraham Munitz for his kindness and help in putting together
our Electromagnetic Levitation system parts and performing early experiments in our lab
at University of California, Riverside.
My gratitude is also extended to Professor Sakhrat Khizroev and his colleagues Dr.
Nissim Amos and Dr. Jeongmin Hong at the Center for 3D Electronics within the
Department of Electrical Engineering for helping me with magnetic characterization
experiments and VSM measurements.
I am truly thankful to all my friends, colleagues and staff in the Department of
Mechanical Engineering at UC Riverside specially Shaahin Amini, Melina Roshandell,
Jun Wang, Roseanna Baron-Lopez, Terry Traver, Katie Dell, Paul Talavera, Sarah
Nosce, Jennifer Morgan, and Becki Jo Ray and Eilene Montoya in the Dean’s office for
their unconditional help and support during these years.
None of this would have been possible without the endless love and patience of my
family. I am really indebted and deeply thankful to my parents, Mohammad Amir and
Nezhat for their faith in me and allowing me to be as ambitious as I wanted. It was under
their watchful eye that I gained so much drive and an ability to tackle challenges head on.
My sisters Leila and Zahra have been a constant source of love, concern, support and
strength all these years. I would like also to express my heart-felt gratitude to my all
extended-family members.
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And last, but not the least, I warmly appreciate the generosity and understanding of my
lovely wife, Fatemeh, who supported me spiritually from the first day of our common life
and never left me alone with this journey until the last day.
Haamun Kalaantari
Riverside
March 2013

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To my all wonderful teachers who believe in diligence, science and
pursuit of academic excellence. Particularly, to my very first
teachers, my mom Nezhat and my dad Mohammad Amir

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ABSTRACT OF THE DISSERTATION

Development of Co-Ni-Ga Ferromagnetic Shape Memory Alloys (FSMAs) by
Investigating the Effects of Solidification Processing Parameters

by

Haamun Kalaantari

Doctor of Philosophy, Graduate Program in Mechanical Engineering
University of California, Riverside, March 2013
Professor Reza Abbaschian, Chairperson

Among Ferromagnetic Shape Memory Alloys (FSMAs), Co-Ni-Ga ternary alloys have
attracted great attention due to their high Curie and martensitic transformation
temperatures as well as improved ductility. Single β phase undergoes the martensitic
transformation in this system, which is the base of ferromagnetic shape memory effect. In
this investigation, Electromagnetic Levitation (EML) technique was employed to assess
the effect of bulk supercooling and rapid solidification on near Heusler-type dual phase
Co Ni Ga and single phase Co Ni Ga (at%) compositions. The effects of γ+β
46 27 27 48 22 30
microstructure on the martensitic and austenitic transformation temperatures and
magnetic properties were also investigated. The presence of γ phase was found to
suppress the martensitic and austenitic transformations to below room temperature. Bulk
supercooling and rapid solidification led to the formation of homogeneous single
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martensitic phase from hyperperitectic alloy, which under normal solidification form the
dual γ+β phases. Moreover, in contrast with martensite forming from Co Ni Ga , the
48 22 30
hyperperitectic martensite in supercooled Co Ni Ga samples showed no grain
46 27 27
boundary microsegregation. The martensite also showed a high Curie temperature about
127°C and good directional magnetic properties, including different in- and out-of-plane
magnetization up to saturation level, and different coercivity from around 14 Oe for in-
plane direction to about 42 Oe at the 50° angle. The role of solidification variables and
chemical composition in the microstructure, and phase transformation in the ternary
alloys Co Ni Ga (at%) with x ranging up to 50, and Co Ni Ga (at%) with y
50 50-x x 100-2y y y
ranging from 15 to 35 were studied as well. For the metastable single β phase of
supercooled Co Ni Ga alloy in Co Ni Ga series, the martensitic transformation
50 22.5 27.5 50 50-x x
showed thermal stability during cyclic cooling and heating (up to 350°C) revealing its
potential as a FSMA candidate. In Co Ni Ga series, on the other hand, paramagnetic
100-2y y y
Co Ni Ga alloy showed martensite to austenite transformation temperature higher than
40 30 30
470°C, indicating its potential as High Temperature Shape Memory Alloy (HTSMA).

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