James L. Mueller Award
Zuhair A. Munir, university of california, davis, usa
Title: Electric field effects in the processing of materials
Abstract: Effects of electromagnetic fields on the synthesis and processing of materials have been extensively investigated for decades. Our investigations, which will be highlighted in this presentation, began by examining the effect of non-contacting electric fields on phase transformation, and crystalline defect distribution and mobility in ionic single crystals starting in the 1970s. With the emergence of self-propagating high-temperature synthesis (SHS) from the former Soviet Union, our work focused next on activating such reactions by electric field, with experimental and modeling studies.
Subsequently our research investigated electromigration and field effects on the crystallization of metallic glasses and the dissolution in liquid metals.
In the 1990s, after the acquisition of a Spark Plasma Sintering (SPS) apparatus, our focus shifted to investigating the fundamental aspects of this process. Experiments were carried out to provide direct demonstration of the role of the SPS current in sintering. The effect of applied pressure on the densification and grain growth of functional oxides was also investigated. An example, high density yttria-stabilized zirconia (YSZ) prepared by the SPS had a grain size of < 20 nm and exhibited unprecedented thermoelectric properties.
Bridge Building Award
Monica Ferraris, Politecnico di Torino, Italy
Title: Joining and integration: Building bridges between materials
Abstract: Robust joining and integration technologies are critically needed for the implementation of advanced ceramics and composite materials in a wide range of applications in energy storage, transportation, aerospace, environmental, and biomedical industries. There are a number of design and manufacturing challenges in the joining of ceramics and ceramic matrix composites to themselves or to other materials. The use of new glasses and glass-ceramics as high temperature pressure-less joining materials for ceramics and ceramic matrix composites will be described, together with some innovative approaches to joining involving surface modification techniques and localized heating. Mechanical testing of joined materials will be also discussed, with particular emphasis on the importance of a standardized, user friendly and reliable shear test for joined materials. A brief virtual tour of
J-TECH@POLITO, an interdisciplinary research centre recently established at Politecnico di Torino on advanced joining technologies will be presented.
This presentation will provide an overview of results, challenges, successes, and (a few) failures, deriving from 30 years of activity in this field by the author and her colleagues at Politecnico di Torino, Italy, together with several research groups from USA, Japan, China, South Korea and EU, showing that joining means building bridges between materials, but also between people.
Julia R. Greer, California Institute of Technology, USA
Title: Materials by design: Three-dimensional (3D) nano-architected meta-materials
Abstract: Creation of extremely strong and simultaneously ultra lightweight materials can be achieved
by incorporating architecture into material design. Dominant properties of such metamaterials are driven by their multi-scale nature: from characteristic microstructure (atoms) to individual constituents (nanometers) to structural components (microns) to overall architectures (millimeters+). To harness the beneficial properties of 3D nano-architected meta-materials, it is critical to assess their properties at each relevant scale while capturing overall structural complexity.
Our research is focused on design, synthesis, and characterization of nano-architected materials using nanofabrication and additive manufacturing (AM) techniques, as well as on investigating their stimulus-driven response as a function of architecture, constituent materials, and microstructure. These “meta-materials” exhibit superior and often tunable properties, i.e. resilience against impact, recoverability, failure suppression, anisotropic stiffness; nano-photonic response (PhCs); new electrochemical degrees of freedom (Li-ion batteries), and shape memory response (SMPs) at extremely low mass densities, as well as lend themselves to novel functionalities (hydrogel-enabled synthesis) which renders them useful and enabling in technological applications. We strive to uncover the synergy between atomic-level microstructure and nano-sized external dimensionality, where competing material- and structure-induced size effects drive overall response. My talk with focus on additive manufacturing via function-containing chemical synthesis to create nano- and microarchitected metals, ceramics, multifunctional metal oxides, and shape memory polymers, as well as demonstrate their potential in some real-use applications. I will describe how the choice of architecture, material, and external stimulus can elicit stimulus-responsive, reconfigurable, and multifunctional response.
Kazunari sasaki, kyushu university, japan
Title: Ceramics for fuel cells and hydrogen energy
Abstract: Whilst we are facing global warming and tough CO2 reduction targets, world-wide energy demand is still increasing. Fuel cells can realize direct electrochemical conversion from chemical energy into electricity. Hydrogen-containing fuels can be used, without combustion, to obtain electricity with high energy conversion efficiency. Electrolysis enables the reverse reaction to produce hydrogen using electricity. Hydrogen energy enables decarbonization of various energy-consuming sectors, long-term carbon-free chemical energy storage, and the long-distance export/import of renewable energy.
Ceramics are key materials for solid oxide fuel cells (SOFCs) for stationary applications, including residential power generation units, industrial co-generation, and distributed power in e.g. data centers. Metal-supported SOFCs may be useful for automobile applications. Similar ceramic materials are used for high-temperature electrolysis. Even for polymer electrolyte fuel cells operated around room temperature, conductive ceramics can be applied as e.g. catalyst supports for longer durability and robustness.
This presentation gives an overview, current status, and future perspectives of fuel cell technologies and hydrogen energy, where ceramics and related composites can take important roles. Technological issues and possible alternative materials of such electrochemical devices are described, with various case studies. Perspectives of hydrogen economy are also discussed.
2021 ECD Global Young Investigator Award
Amjad Almansour, nasa glenn research center, usa
Title: Understanding the durability of SiC based ceramic matrix composites (CMCs) for gas turbine engine hot section components
Abstract: Silicon carbide fiber reinforced silicon carbide ceramic matrix composites (SiCf/SiC-CMCs) are being used in the fabrication of gas turbine engine hot section components due to their light weight and excellent thermal and chemical stabilities at high-temperature. These superior properties enable significant enhancements in engine efficiency and reduced fuel burn, emissions, and cooling requirements.
In support of NASA’s Aeronautics Mission under various programs at Glenn Research Center, different types of composites have been developed and assessed for a high temperature (2700 °F) SiCf/SiC CMC system for turbine engine applications. These composites have creep-resistant SiC fibers, advanced 3D weaves, 2700 °F-capable hybrid SiC matrices, and durable environmental barrier coatings (EBCs). These efforts have resulted in improvements in the overall CMC thermomechanical and environmental durability.
In order to study the role of different constituents and processing variables, a single fiber tow CVI (chemical vapor infiltration) SiC/SiC minicomposite can be considered the basic architectural feature of woven and laminate SiC/SiC CMCs. Moreover, the minicomposite mechanical and tensile creep damage behavior represents the creep behavior of 0° fiber tows in the axial loading direction of a macrocomposite or component. In addition, a large number of minicomposite samples can be fabricated at relatively low cost within a short time, which makes them attractive for obtaining a robust set of experimental data and studying constituent behavior. In this presentation, the minicomposite approach to study damage mechanisms that limit CMC life in extreme environments including exposure to steam will be presented. The effects of constituent type and volume fraction on the CMC durability, which will help influence CMC design, will be discussed.
2021 ECD Jubilee Global Diversity Awards
Eva Hemmer, university of ottawa, canada
Title: Rare-earth-based opto-magnetic nanoparticles – Current trends and challenges
Abstract: Today’s world faces global challenges, such as Societal Health and Energy Concerns, that have to be addressed for a sustainable development. While none of these concerns is easy to solve, material scientists are designing the building blocks that are key to sustainable energy and health strategies. Advanced optical materials act as novel optical probes for theranostics. Novel optoelectronic/magnetic nanomaterials will increase device efficacy and endow them with yet unseen multifunctionality. Herein, the remarkable optomagnetic properties of the rare-earths (RE) make RE-based materials ideal for biomedical or energy applications. Yet, challenges remain; low emission intensity and efficiency of small nanoparticles (NPs), and reliable, fast synthesis routes. As material chemists, we tackle these challenges with new designs of RE-NPs by chemically controlled synthesis, application-oriented surface chemistry, and understanding of structure-property-relationships. Sodium rare-earth fluorides (NaREF4) are our favorite materials. We developed a fast and reliable microwave-assisted synthesis approach allowing crystalline phase and size control in the sub 15nm realm. These NPs exhibit upconversion and near-infrared emission, which makes them excellent candidates for optical applications, while they are promising nanoparticle-based magnetic resonance imaging contrast agents due to their magnetic properties.
Jessica A. Krogstad, University of Illinois, Urbana-Champaign, USA
Title: Dynamic, radiation tolerant ceramics: Understanding defect mobility and microstructural evolution in ceramics subject to ion irradiation
Abstract: Irradiation induced microstructural changes, facilitated by defect accumulation and radiation enhanced diffusion, can have significant consequences for a material. This is well documented in metallic systems but the same phenomena are not as well understood in ceramics. For example, the successful strategy using nanocrystalline or nanolaminate microstructures to increase the defect sink density has been demonstrated in a wide range of metallic systems; however, when the same strategy is employed for ceramics, growth of the nanocrystalline grains frequently leads to microcracking. Porous ceramics may provide the necessary combination of defect sinks and microstructural compliance to achieve an invariant microstructure that successfully suppresses radiation driven microstructural evolution. The underlying mechanisms contributing to the stability of porous ceramics are revealed through a combination of in-situ and ex-situ irradiation studies designed to isolate defect generation, interaction and transport behaviors. First, a new method for extracting radiation enhanced diffusivity data from in-situ irradiation of nanoparticles will be demonstrated and then applied to the evolution of nanocrystalline-nanoporous microstructures irradiated ex-situ. To compliment this, we will explore the interactions between defects as a function of the incident ion energy and how these interactions influence defect mobility, microstructural stability and potential functionality of ceramics.
Miki Inada, Kyushu University, Japan
Title: Microwave effect on the synthesis of metal oxide particles by hydrothermal method
Abstract: Microwave process has been developed as one of hydrothermal processes for synthesis of fine oxide particles. Microwave is absorbed directly into water as solvent and enables the rapid heating compared to a conventional heating process. In our study, some interesting phenomena were observed on the synthesis of oxide powders under microwave irradiation, such as promotion of crystal growth, change in formed crystalline phase and smaller particle size.
The noteworthy phenomenon of microwave irradiation is the selective heating of high-dielectric solvent. Microemulsion method is useful to synthesize spherical oxide particles. W/O emulsion consists of oil phase as matrix and water phase as micelle surrounded by organic emulsifier. Spherical oxide particles are prepared by heating of water micelles including reactants. We synthesized spherical mesoporous silica and silica-titania particles by sol-gel method using W/O emulsion under microwave irradiation, in which the oil phase does not absorb microwave, whereas the water phase is selectively heated under microwave irradiation. The selective heating of water phase enhances the chemical reaction in micelles, whereas the cooling of micelle surface by oil phase stabilizes emulsifier molecules, leading to stable formation of spherical oxide particles.