DESIGN, ASSEMBLY AND CHARACTERIZATION OF COMPOSITE ...

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VITA Jian Xu Candidate for the Degree of Doctor of Philosophy Thesis: DESIGN, ASSEMBLY AND CHARACTERIZATION OF COMPOSITE STRUCTURES OF BARIUM TITANATE AND NICKEL Major Field: Chemical Engineering Biographical: Personal Data: Jian Xu was born in Feburary 10, 1976 in Zhenjiang, Jiangsu Province, China as the son to Jinlin Xu and Ping Hu. Education: He attended Central South University, China in 1994 and received Bachelor of Engineering in Chemical Engineering in 1998. After working for three years in the industry, he began his graduate study at Oklahoma State University in 2001. He obtained his Master of Science degree in Chemical Engineering at in December 2004, with a thesis on self-assembly of colloidal particles. Then he continued graduate study and completed the requirements for the Doctor of Philosophy in Chemical Engineering at Oklahoma State University, Stillwater, Oklahoma in May 2010. Experience: He worked in Gold East Paper (Jiangsu) Co. Ltd. (Asia Pulp & Paper) for one year in Zhenjiang, Jiangsu Province, China. Then he worked for less than two years in a manufacturer plant of SAE Magnetics (HK) Ltd. in Dongguan, Guangdong Province, China Professional Memberships: He was a student member of Material Advantage program.
Name: Jian Xu Date of Degree: May, 2010 Institution: Oklahoma State University Location: Stillwater, Oklahoma Title of Study: DESIGN, ASSEMBLY AND CHARACTERIZATION OF COMPOSITE STRUCTURES OF BARIUM TITANATE AND NICKEL Pages in Study: 241 Candidate for the Degree of Doctor of Philosophy Major Field: Chemical Engineering Scope and Method of Study: Three dimensional, heterogeneous, geometrically complex ceramic-metal composite structures are fabricated by assembly of aqueous colloidal gels of barium titanate and nickel, followed by densification of ensembles in controlled atmosphere through sintering. This work focuses on the processing of colloidal gels, assembly of the composite structures, and cosintering of composite structures. Relevant sintered material properties including oxidation, hardness, microstructure, and electric properties are characterized. Specifically, rheological characterizations are used to determined colloidal gel formulations; sintering shrinkage is used as a function of temperature to determined compatible gel compositions; thermogravimetric analysis is used to characterize thermal degradation and oxidation of polymer additives and carbon black support material, respectively. Findings and Conclusions: The findings of this study are four folds: 1) a carbon black gel may be used as fugitive materials for assembly of geometrically complex objects; 2) a nickel gel may be used to assemble objects that have >99% density; 3) barium titanate and nickel composite structures that have a low solid volume fraction of nickel may be assembled and consolidated through solid state sintering, and 4) barium titanate and nickel composite structures that have a high solid volume fraction of nickel may be assembled and consolidated through liquid phase sintering. The use of small additions of sintering aids allows successful densification of composite structures that have discrete interface, heterogeneous composition, and intricate geometric design. Low internal stress and plastic deformation of particle network during liquid phase sintering process facilitate the co-sintering of dislike ceramic and metal materials. ADVISER’S APPROVAL: James. E. Smay
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DESIGN, ASSEMBLY AND CHARACTERIZATI
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ACKNOWLEDGEMENTS First and foremost
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CHAPTER 5 BARIUM TITANATE NICKEL CO
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Table 6.1 Formulations of aqueous c
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Figure 2.12 Schematic illustrations
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Figure 2.35 Schematic of the SHS pr
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Figure 4.9 Sintered nickel lattices
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Figure 6.12 Optical image of the cr
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1.1. Motivation CHAPTER 1 INTRODUCT
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and characterizing rheological prop
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2.1. Materials System CHAPTER 2 BAC
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2.2. Reentrant Structures and Ceram
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devices would provide self-sustaini
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a) b) Figure 2.4 Schematic illustra
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production of concept models, injec
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Fused Deposition Modeling (FDM) was
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Laser Engineered Net Shaping (LENS)
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Inkjet printing (IP) 27 is based on
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Table 2.1 Comparisons of various SF
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Figure 2.11 Processing steps involv
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2.4.1 Colloidal Inks The printing i
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Robocasting has lacked a well-desig
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Table 2.2 Example polymers that dep
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2.6. Sintering In robocasting, sint
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Figure 2.15 Sphere and plate model
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where
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2.5.3 Solid State Sintering In this
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Figure 2.18 Illustration of neck gr
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2.5.3.4 Final Stage During this sta
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Figure 2.23 Schematic diagram of th
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2.5.4.2 Rearrangement With the form
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2.5.4.6 Spreading of Sintering Aid
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Driven by reduction of free energy,
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2.5.5 Sintering Atmosphere Sinterin
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2.7. Composite Materials In this re
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Figure 2.29 Types of composite mate
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Table 2.6 Examples of composite mat
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Table 2.7 Examples of FGM applicati
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2.7.3 Processing For the fabricatio
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prepared discrete layers of uniform
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Powder densification processes gene
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The specific volume fraction beyond
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a) b) Figure 2.34 a) Volume fractio
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When the powders are densified in s
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Various FGM coating processes are a
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of FGMs, such as partially reactive
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leading to a characteristic time τ
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3.1 Introduction CHAPTER 3 AQUEOUS
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occurs in a multi-step process: fir
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a) b) Figure 3.1 a) SEM image of as
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3.2.3 Preparation of Carbon Black C
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3.2.5 Drying Shrinkage Characteriza
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the optimized surfactant concentrat
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The storage modulus of a colloidal
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For HA ink, yield stress
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In the case of the aqueous carbon b
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PPO units of Pluronic F-127 may ads
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a) b) Figure 3.6 A carbon black lat
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a) b) Figure 3.7 SEM images of a) c
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TGA plot is in agreement with previ
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a) b) Figure 3.9 Thermogravimetric
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3.3.8 Fabrication of Complex Cerami
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c) d) 109
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3.4 Conclusion A fugitive support m
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metal inks have been reported for R
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Midland, MI) 5% by weight stock sol
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4.2.5. Thermal Degradation of Binde
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4.3. Results and Discussion 4.3.1.
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4.3.2. Preparation of Nickel Ink Su
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260 °C for 8 hours, the residual c
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Table 4.1 Calculated residual carbo
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a) b) Figure 4.6 Sintered Ni struct
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temperature 138, 139 lead to 92-95%
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Figure 4.8 Scanning electron microg
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c) Figure 4.9 Sintered nickel latti
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5.1. Introduction CHAPTER 5 BARIUM
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materials within the overall struct
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40:60, 60:40, 80:20 are separately
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5.2.3. Rheological Characterization
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5.2.5. Co-sintering and Re-oxidatio
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mixing, BT and Ni phases appear uni
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The combined use of PAA and PAA-90K
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To quantify this difference in sint
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As the BT and Ni particles used in
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The reducing atmosphere used in the
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Figure 5.7 Vickers hardness number
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5.3.6. Fabrication of BT-Ni composi
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modify the sintering kinetics of th
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a) b) Figure 5.10 Co-sintered compo
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5.4. Conclusions Freeform fabricati
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Liquid phase sintering involves usi
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(pH=4.4, 31.5% by weight) (Adva Flo
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concentration of 7 mg/mL in the aqu
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Table 6.1 Formulations of aqueous c
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thickness. Each layer of the struct
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6.2.6. Hardness Test Microindentati
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micrographs for these two powders.
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Second, the added LiAC∙2H2O is am
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Figure 6.3 Oscillatory behavior for
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a) b) Figure 6.4 Sintering strain c
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mass transport in LFBT network. 167
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The above discussion is mainly focu
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Figure 6.8 shows the bowtie-shaped
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Page 219 and 220: 6.3.7. Piezoelectricity and Dielect
Page 221 and 222: 6.4. Conclusions Aqueous colloidal
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Page 225 and 226: 3. Development of aqueous colloidal
Page 227 and 228: 7.2. Recommendations In the context
Page 229 and 230: gelation behavior. κ-carrageenan i
Page 231 and 232: REFERENCES 1. Larsson 9301647, 1993
Page 233 and 234: 29. Simchi, A.; Petzoldt, F.; Pohl,
Page 235 and 236: 61. Bouvard, D., Acta Metallurgica
Page 237 and 238: 92. Morissette, S. L.; Lewis, J. A.
Page 239 and 240: 120. Boehm, H. P., Some Aspects of
Page 241 and 242: 150. Atkinson, A., Growth of Nio an
Page 243 and 244: APPENDICES A. Mathematical Modeling
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Page 247 and 248: conditions: Equation A.12 is solved
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Page 251 and 252: a) b) Figure B.1 a) Freeze-dried st
Page 253 and 254: a) Figure C.1 Cr-Ni lattices of 5Cr
Page 255 and 256: E. Binary Phase Diagram of ZnO-B2O3
Page 257: References A.1. Du, Z., Sarofim, A.
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