Mechanical & Aerospace Engineering_45

142 Pages·2008·10.38 MB·English

POLYMER DERIVED CERAMICS: PROCESSING
–STRUCTURE–PROPERTY RELATIONSHIPS
By
SURAJ C. ZUNJARRAO
Bachelor of Engineering in Mechanical Engineering
University of Pune
Pune, Maharashtra, India
2001
Master of Science in Mechanical Engineering
State University of New York at Stony Brook
Stony Brook, NY, USA
2005
Submitted to the Faculty of the
Graduate College of
Oklahoma State University
in partial fulfillment of
the requirements for
the Degree of
DOCTOR OF PHILOSOPHY
May, 2008
COPYRIGHT (cid:13)c
By
SURAJ C. ZUNJARRAO
May, 2008
POLYMER DERIVED CERAMICS: PROCESSING
–STRUCTURE–PROPERTY RELATIONSHIPS
Dissertation Approved:
Dr. Raman P. Singh
Dissertation Advisor
Dr. Hongbing Lu
Dr. Jay Hanan
Dr. Jim Puckette
Dr. A. Gordon Emslie
Dean of the Graduate College
iii
ACKNOWLEDGMENTS
As I sit down to write this page, I am filled with a great sense of gratitude
towards so many who have made this journey possible, but above all, towards my
advisor Prof. Raman P. Singh, for taking me under his wing and guiding me with
such kindness throughout my life as a graduate student. He has been an incredible
mentor and his superlative expertise in this field of research has kept me firmly rooted
on the right track. Dr. Singh’s clarity of thought, ability to see the big picture and
optimism has pulled me out of despair so many times, when I saw no light at the
end of the tunnel. He kept faith in me and provided encouragement as I stumbled
during those early stages of PhD qualifiers, and I am immensely grateful for that.
All these years, it has been a delight to stop by his office for a chit-chat on anything
from current events in the science and politics to computer games and movies. His
humility, attitude of fairness, believing in and extracting the best out of others and
yearning for giving back to the society are truly inspiring.
I wish to thank Dr. Jay Hanan, Dr. Hongbing Lu, Dr. Jim Smay and Dr. Jim
Puckette for being on my dissertation committee. Special thanks to Dr. Puckette
for filling in for Dr. Jim Smay at such a short notice. I am sure Dr. Puckette will
remember me as the MAE student annoyingly showing up at his office door every
other day to enquire about the XRD machine. I am thankful for his kindness and
tolerance. During the course of my work, I found myself seeking Dr. Hanan’s help
every time I was stuck analyzing my XRD data and I am thankful for his willingness
to help every time. I am very thankful to Dr. Hongbing Lu for his guidance in the
finite element modeling work. Discussions with him helped me avoid going astray in
iv
the final stages, when time was a premium.
I would also like to thank Dr. Toshio Nakamura, Dr. Chad Korach and Dr. Hui
Zhang for their help and support at Stony Brook University. Special thanks are
due to Dr. John Metzger for co-advising me on the ‘microwave project’ and for his
delightfully energetic and cheerful disposition.
I have made many friends at Stony Brook University and Oklahoma State Uni-
versity who shared the hardships of graduate student life. I would particularly like
to thank all the past and current members of Mechanics of Advanced Materials Lab;
people who were my seniors when I joined the lab: Mei Zhang, Dr. Pavan Vaddadi,
BhaveshKansara,VasilTasovski,AlainsGratien,Dr.RaviSriram; andmycolleagues:
AbhishekSingh, EnginOzcivici, PawelDyjak, Dr.SehajSingh, Dr.GajendraPandey,
Dhivakar Jeevan Kumar, Arif Rahman and Chirag Karelia.
A heartfelt thanks to my very good friend Abhishek Singh for his friendship,
humility and encouragement. I also thank Abhishek, his wife Kavita and their lovely
daughter Anushka for making me a part of their family. I wish to thank Dr. Gajendra
Pandey for his help and encouragement. Looking back, those reviving tea-smoke
breaks (chai-sutta) were the near perfect way of scrutinizing progress. I am amazed
that some of the best ideas have come from the casual discussions during such breaks.
Thanks are due to friends outside the lab:
• Friends at Stony Brook University, particularly Narayanan Ramanujam, Swet
Chandan, Samrat Chawda, Prashant Jha, Xiaolin Wang and Shan-Shan Liang.
• All the people of the ‘Khaplass Gang’, especially Aditya “Gotya” Gokhale,
Aditya “Ooty” Pradhan, Sameer “Khass” Sawant, Sagar “Detergent” Khare,
Milind “Tau” Yadav, Swapnil “Taklya” Patil, Abhijit “Khavnya” Khavnekar
and Yogesh “Bheem” Sawant. These blokes made my time at Stony Brook
truly memorable.
v
• Friends at Oklahoma State University, particularly Hrishikesh Bale and his
wife, Ridhima, Nitin Daphlapurkar, Dr. Bharat Joshi, Saurabh Pawar, Amol
Ganpatye, Abhay Mane, Kartik Bhat and others.
I would like to thank my “internet” friends at ‘The Forgotten Patrol’, particu-
larly George <Mrrwizzard> Clay, Craig <blood> Graham, Jack <bait> Kong, Nick
<tooters> Lidster and Brandon <‘eskIm0> Charbonneau for gaming session at un-
earthly hours which served as the perfect getaways and helped me keep my sanity.
Last, but not the least by any stretch, I want to thank my parents, my brother,
Darshan, and his wife, Prerana, for the support and backing I received through all
these years. I would not be at this stage without their support and encouragement.
vi
TABLE OF CONTENTS
Chapter Page
1 Introduction 1
1.1 Processing of Ceramics . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1.1 Powder Sintering . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1.2 Reaction Processing . . . . . . . . . . . . . . . . . . . . . . . 4
1.1.3 Non-powder–based Processing . . . . . . . . . . . . . . . . . . 5
1.1.4 Polymers Derived Ceramics . . . . . . . . . . . . . . . . . . . 7
1.2 Silicon Carbide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.3 Nanocrystalline Ceramics . . . . . . . . . . . . . . . . . . . . . . . . . 10
1.4 Objective of this Investigation . . . . . . . . . . . . . . . . . . . . . . 13
2 Background and Literature Survey 16
2.1 Processing of preceramic polymer . . . . . . . . . . . . . . . . . . . . 16
2.2 Allylhydridopolycarbosilane (AHPCS), as a precursor for SiC . . . . . 17
2.2.1 Mechanical properties of AHPCS derived SiC . . . . . . . . . 19
2.2.2 Microstructure Characterization of AHPCS–derived SiC . . . 20
2.2.3 Structure–Property relationships for AHPCS derived SiC . . . 21
3 Experimental Procedure 23
3.1 Material Fabrication . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
3.1.1 Preliminary Experiments and Setup . . . . . . . . . . . . . . . 23
3.1.2 Effect of Processing Parameters . . . . . . . . . . . . . . . . . 27
3.1.3 Fabrication for Bulk Testing . . . . . . . . . . . . . . . . . . . 27
vii
3.2 Physical Characterization . . . . . . . . . . . . . . . . . . . . . . . . 29
3.3 Mechanical Characterization . . . . . . . . . . . . . . . . . . . . . . . 32
4 Results and Discussion 34
4.1 Polymer–to–Ceramic Conversion . . . . . . . . . . . . . . . . . . . . . 34
4.2 Amorphous to Amorphous/Nano–crystalline Conversion . . . . . . . . 37
4.3 Mechanical Property Characterization . . . . . . . . . . . . . . . . . 45
5 Finite Element Modeling 55
5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
5.2 Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
5.3 Polycrystalline Models . . . . . . . . . . . . . . . . . . . . . . . . . . 66
5.4 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
6 Conclusions and Future Work 81
BIBLIOGRAPHY 85
A Matlab code to generate Voronoi diagram 104
B Code in C to create grains from seeds and vertices of voronoi dia-
gram 110
C Code in C to apply isotropic compression to Voronoi grains and
calculate crystalline volume fraction 117
D Sample PYTHON code to create a model in ABAQUS with 1 grain
and 1 grain boundary, developed as individual parts 121
E Sample PYTHON code to create a 2 dimensional model in ABAQUS
as single part with 10 grains in a unit square 124
viii
LIST OF TABLES
Table Page
3.1 Properties of STARFIRE SMP–10 as obtained from Starfire Systems
Co., Malta, New York, USA . . . . . . . . . . . . . . . . . . . . . . . 24
4.1 Biaxial strength of the SiC–SiC composites fabricated by using PIP
route and tested using RoR biaxial flexure test . . . . . . . . . . . . . 53
5.1 Approximate average grain sizes obtained for 100 grain models with
given crystalline vol. fraction. . . . . . . . . . . . . . . . . . . . . . . 67
5.2 Number of grains required to achieve models containing grains averag-
ing 10 nm in size, occupying different volume fractions. . . . . . . . . 68
5.3 Number of grains required to achieve 80% crystalline volume fraction
with predetermined grain sizes. . . . . . . . . . . . . . . . . . . . . . 71
5.4 Elastic modulus obtained for models with the same crystalline volume
fraction of 80% and having different grain sizes. . . . . . . . . . . . . 80
ix
LIST OF FIGURES
Figure Page
1.1 Steps typically involved in making ceramics using conventional powder
processing route. [1]. . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.2 Different methods categorized as reaction processing along with their
relative rate of reaction. [9]. . . . . . . . . . . . . . . . . . . . . . . . 4
1.3 Schematic representation of molecular and microstructural transitions
during ceramic manufacturing from preceramic polymers. [26]. . . . . 8
2.1 Examples of the polymers as precursors to Si-C-N based ceramics [89]. 17
2.2 Diagrammatic representation of AHPCS structure [103]. . . . . . . . 18
3.1 Setup used for inert gas pyrolysis up to 900◦C . . . . . . . . . . . . . 25
3.2 New tube furnace setup used for inert gas pyrolysis up to 1650◦C . . 26
3.3 Setupoftrapstopurifyargonfedtothetubefurnace. Theseinclude: a
cartridgeremovingmoistureandorganics, acartridgeremovingoxygen
and a third indicator cartridge to warn of system saturation. Finally
there is an indicating moisture removal trap. . . . . . . . . . . . . . . 26
3.4 Schematic of PIP process for fabrication of bulk samples for bulk char-
acterization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
3.5 Schematic of fixture for testing biaxial flexure properties using RoR. . 33
4.1 IR Spectra for AHPCS heated to 300◦C (i), 500◦C (ii), 700◦C (iii),
900◦C (iv) and 1150◦C (v). . . . . . . . . . . . . . . . . . . . . . . . 35
x