ICACC’13 Plenary and Award Speakers
Anil V. Virkar, Distinguished Professor, Department Chair, College of Engineering, Department of Materials Science and Engineering, University of Utah
Title: Failure of Ceramics under Externally Applied Loads and Internally Generated Pressures: Zirconia, a Unique Material
Abstract: Stabilized zirconia exists in two crystallographic forms, cubic and tetragonal. Zirconia has been extensively investigated for various applications which exploit its ionic transport properties, its refractory properties and its excellent mechanical properties. Solid oxide fuel cells, sensors, electrolyzers, thermal barrier coatings, heating elements, ball bearings, medical implants, etc. are some of the applications. Tetragonal zirconia is known for its excellent mechanical properties attributed to t → m martensitic transformation and ferroelasticity. Excellent oxygen ion conductivity of zirconia is the reason for its use in fuel cells, electrolyzers. In many mechanical and electrochemical applications, zirconia exhibits failure in service under some conditions. The commonly experienced failure is under externally applied loads. Increase in fracture toughness and strength achieved through processing, microstructure control, etc. lead to greater reliability. This has been extensively investigated. However, cracking of zirconia also occurs under electrochemical conditions. Such failures occur under internally generated pressures. While cracking occurs in both types of failures, the origin and mechanisms can be very different in the two cases. Conventional approaches of increasing strength and toughness have little role in mitigating failures that often occur in electrochemical systems. Rather, ion and electron transport properties determine whether failures can be mitigated. Additionally, even the mechanism of cracking is also different from failures observed under externally applied loads. The two different modes of fracture will be compared and contrasted. In external loading, one seeks solutions to fracture mechanical problems by solving elasticity equations. In electrochemical systems with internally generated pressures, a coupling exists between electrochemical transport (e.g. solution to transport equations) and mechanics. This leads to different cracking patterns. Under external loading, failure is almost always catastrophic (barring subcritical crack growth related issues). However, under internal loading, failure is stable and not abrupt. The two different modes of failure will be compared and contrasted.
Biography: Virkar is a cofounder and Vice President of Materials and Systems Research, Inc., a small company based in Salt Lake City, Utah; a co-founder of Versa Power Systems, a Colorado-based company with operations in Calgary and serves on its board. He also was a founding member of Ceramatec, Inc., a small company based in Salt Lake City, Utah. Recently, he along with a few colleagues have formed a new venture named Nano-Oxides, Inc. He is a member of the National Academy of Engineering. Virkar received B.Tech. (Hons.) in Metallurgical Engineering from Indian Institute of Technology, Mumbai, India (1967); M.S. in Engineering Mechanics from Louisiana State University (1969); and Ph.D. from Northwestern University in Materials Science (1973). His research interests include ceramics, ionic and electronic conductors, fuel cells, batteries, solid state electrochemistry, renewable energy, sensors, transport, thermodynamics of high temperature materials; and fracture of materials.
Bridge Building Award
Tatsuki Ohji, Prime Senior Research Scientist, National Institute of Advanced Industrial Science and Technology (AIST) and Designated Professor in the Graduate School of Science and Engineering, Meijo University
Title: Microstructural Evolution and Mechanical Properties of Engineering Ceramics
Abstract: Ceramic materials are composed of a variety of structural elements, including, defects, grains, particles, pores, fibers, layers, and interfaces at different scale levels. In terms of size, the structural elements can be classified into four categories: (1) atomic and molecular scale, (2) nano-scale (order of 10-6 mm), (3) micro-scale (order of 10-3 mm), and (4) macro-scale. It is possible to realize new or unique performance or markedly improve properties in ceramics, by controlling systematically these structural elements. Taking, as an instance, silicon nitride which is one of the most widely used engineering ceramics, this paper intends to show that the mechanical properties including strength, toughness, and creep resistance can be tremendously improved when the sizes, morphologies, orientation, distribution, etc. of grains and pores as well as grain boundary structure are carefully controlled. Examples are: (1) super strong silicon nitride with >2 GPa strength via refinement and alignment control of grains, (2) porous silicon nitride with high strength (>1 GPa), and high toughness (300-500 J/m2; far higher than that of the dense) via morphology and alignment control of grains and pores, and (3) super heat resistant silicon nitride with strength retention up to 1500oC and toughness of ~800 J/m2 (double that of cast iron). The paper also focuses on improved mechanical properties via microstructure control for high thermal conductivity silicon nitride, which is expected to be applied as substrate materials in future power devices.
Biography: Ohji earned his BS and MS in mechanical engineering from Nagoya Institute of Technology and PhD in inorganic materials engineering from Tokyo Institute of Technology, he has authored or coauthored more than 330 peer-reviewed papers and 12 book chapters, edited 30 books and conference volumes, chaired or co-chaired more than 20 international conferences and symposia, and holds more than 40 patents. A recipient of numerous honors and awards, he is a Fellow of the American Ceramic Society and ASM International, and Academician of the World Academy of Ceramics. He serves as a Governor of Acta Materialia, Inc., and on the editorial boards of many international journals including International Materials Reviews, Journal of the American Ceramic Society, and International Journal of Applied Ceramic Technology. His research interests include mechanical property characterization of ceramics, ceramic composites and porous materials, microstructural design of ceramic materials for better performance, and green manufacturing of ceramic components. He was a Chair of the American Ceramic Society’s Engineering Ceramic Division in 2010-2011.
Bruce Dunn, Nippon Sheet Glass Professor of Materials Science and Engineering, UCLA
Title: Designing Ceramics for Electrochemical Energy Storage Devices
Abstract: The ability to design the chemistry and nanostructure of ceramics is having a profound effect on the performance of electrode materials for electrochemical energy storage. Some of the key advances in this field will be discussed in this presentation. In the lithium-ion battery field, improvements in energy and power densities are attributed to the development of nanoscale materials which exhibit shorter ion and electron diffusion lengths. The development of carbon coatings and core-shell materials represents another significant advance in the design of electrode materials. This approach enables new families of poorly conducting oxides to be used as insertion electrodes. Mesoporous transition metal oxides are also emerging as an important direction in the energy storage field. The mesoporous architecture provides electrolyte access to redox-active walls and enables higher energy densities to be attained. The energy storage field faces a number of future challenges and these items will also be discussed.
Biography: Dunn was a staff scientist at the General Electric Research and Development Center before joining UCLA. His research interests concern the synthesis of organic-inorganic materials and characterization of their electrical, optical, biological and electrochemical properties. A continuing theme in his research is the use of sol-gel methods to synthesize materials with designed microstructures and properties. His recent work on electrochemical energy storage includes three-dimensional batteries and pseudocapacitor materials.
Sangmok Lee, Chief Executive Director, Korea Institute of Industrial Technology (KITECH) in the Incheon Regional Division
Title: Novel Materials Development – What’s next? – The role of Root Industry Technology
Abstract: “Root Industry Technology” symbolically refers to an integration of six production technology groups; casting, molding, forming, welding, heat treatment, and surface treatment. The Root Industry Technology includes materials and process technologies, which are hidden behind products, and do not appear frequently in the foregrounds, however they represent important fundamental basis for the high-tech industrial R&D. For instance, novel materials developed through basic materials science strategies could be reformed into value-added components and final products by the proper support and integration of Preliminary Root Industry Technology. As the function of components and products becomes increasingly complex and robust, the importance of the root technologies has grown further and greater. In this presentation, the successful story of the change of Root Industry Technology from 3 D (Dangerous, Dirty, and Difficult) to ACE (Automatic, Clean and Easy) will be introduced to demonstrate its influence on the developments of novel materials such as eco-Magnesium and alloys, rare metals, and amorphous & nanostructured materials. Based on our technology platforms driven by Root Industry Technologies, these developments could be transferred into valuable components and commercialized products used in the various core industries.
Biography: Lee received his BS degree (1986), MS degree (1989), PhD degree (1997) in Metallurgical Engineering from Yonsei University in Seoul, Korea. He was a visiting researcher at Oxford University with the British Council Scholarship during 1994-95. He has worked at KITECH since 2001, serving as the Director of Korea Eurasia Cooperation Centers from 2005 to 2011. His main research interests are casting technology and Root Industry Technology, which is a main focus of the Incheon Regional Division. He has served as a PI on over 200 programs sponsored by Ministry of Knowledge and Economy of Korea, and he also collaborates very actively with researchers at institution in Korea, US, Europe, China and Japan. He holds 20 patents and has authored/co-authored nearly 200 original research publications. He is a Member of Board of Directors in Korean Institute of Metals and Materials and Korea Foundry Society. Also he is a chairman of semi-solid subcommittee in Korea Society for Technology of Plasticity and International Cooperation Committee in Korea Foundry Society.