James L. Mueller Award
William J. Weber, University of Tennessee, USA
Ion-Beam Modification and Nanostructure Evolution in Ceramics
Abstract: Ion-beam modification is a result of both inelastic energy loss to electrons and elastic energy loss to atomic nuclei. The effects of these different energy loss pathways on defect production, nanostructure evolution and phase transitions in ceramics are complex. Using experimental and computational approaches, the separate and coupled effects of energy loss to electrons and atomic nuclei on ion-beam modification of ceramics have been investigated over a range of ions and energies. These studies demonstrate: 1) formation of nanoscale phase transitions by high electronic energy dissipation and by synergistic effects between pre-existing defects and electronic energy loss; 2) coupled effects of energy loss to electrons and atomic nuclei on nanograin growth; and 3) ionization-induced defect annealing. The diverse range of effects provides new paradigms in ion-beam modification of ceramics on the role of electronic energy loss in defect engineering and functional nanostructure formation. This research has advanced understanding on the role of defects in electronic energy dissipation and electron-phonon coupling, and the knowledge gained provides insights for creating novel interfaces and nanostructures with controlled morphologies, phases and local strain, which can be employed to engineer functionalized thin film structures with tunable electronic, ionic, magnetic and optical properties.
Bridge Building Award
Toshihiro Ishikawa, tokyo university of science, japan
Development of precursor ceramics using organic silicon polymer
Abstract: This presentation will discuss our unique precursor ceramics developed by author and coworkers in Ube Industries, Ltd.. We have developed many types of functional ceramics using polycarbosilane as a raw material. Since 1983, several grades of SiC-based fibers have been produced from polycarbosilane in Ube Industries, Ltd.. Of these grades, we developed the highest heat-resistant SiC-polycrystalline fiber (Tyranno SA), which can withstand up to 2000oC, using organic silicon polymer containing small amount of aluminum as a starting material (T.Ishikawa, et al, Nature, 391 (1998) 773). In the same year, we also developed a new type of tough, thermally conductive SiC composite (SA-Tyrannohex) with high strength up to 1600oC in air. This ceramic consists of a highly ordered, close-packed structure of very fine hexagonal columnar SiC-fibers with a thin interfacial carbon layer between them (T.Ishikawa, et al., Science, 282 (1998) 1295). Furthermore, we successfully developed a strong photo-catalytic fiber (TiO2/SiO2 fiber) with a gradient surface layer composed of TiO2-nanocrystals making the best use of controlled phase separation (bleed out) of additives (titanium(Ⅳ)tert-butoxide) contained in polycarbosilane (T.Ishikawa, et al., Nature, 416 (2002) 64). In this presentation, the development story and subsequent progress will be discussed.
katalin Balázsi, Institute for Technical Physics and Materials Science, Centre for Energy Research, Hungarian Academy of Sciences, Hungary
Ceramic biomaterials: From traditional technologies to novel applications
Abstract: The 400 000 artificial hip joint operations made every year in the word and there are 25 000 000 people with a total hip replacement. The wear and risk of the implant loosening increases so that after 10 years 10-20% of the implants have to be renewed. Biomaterials used for implant should possess some important properties in order to long-term usage in the body without rejection. The biocompatibility, mechanical, chemical and surface properties play a key role in the creation of sufficient and long term functional replacements. New fundamental research outcomes with industrial perspectives are given for understanding the applications of ceramics in load-bearing and low-load-bearing bioimplants with directions for future developments.
Nowadays, Si3N4 is a new bioceramic with extremely good mechanical properties. Hydroxyapatite (HA) is a widely used bioceramic in implantology considering its high bioactivity. A bioactive coating (HA) on the bioinert ceramic implant’s surface (Si3N4) could help avoid the rejection from the body in the critical early few days after the operation. The preparation of bioceramics will be showed from traditional technologies to novel applications. The main trends and fundamental scientific problems will be discussed.
George T. (rusty) gray, iii, los alamos national laboratory, usa
Developing a pathway to microstructure-aware predictive capability for the shock / dynamic response of materials
Abstract: It is sixty years since Cyril Stanley Smith’s seminal paper describing the effects of shock loading on the structure / property behavior of materials. While numerous experimental observations have fostered the correlation of post-shock microstructural parameters, such as dislocations, point defects, deformation twins, shock-induced phase products, etc., quantitative predictive capability of the defect generation and damage evolution in materials has yet to be realized. Broadly based defect generation/storage phenomenology presenting a unified view of the material structure/property aspects of shock-wave deformation has proven very difficult. However, changes in design and manufacturing paradigms applied to events dominated by dynamic-loading processes have placed increased emphasis on developing physically-based predictive materials models of shock effects on materials as well as amazing innovations in in-situ shock diagnostics. In this talk, a survey of the evolution in the state-of-our-understanding of defect generation and damage evolution is discussed and thoughts on the evolving capabilities to move shock / dynamic behavior of materials research from observation to design and control is presented. Examples of how utilizing “real-time”, post-mortem, and “in-situ” experimental approaches together are needed to facilitate quantification 4D processes during dynamic / shock-wave loading will be discussed.
2020 ECD Global Young Investigator Award
Sungwook Mhin, Korea Institute of Industrial technology, korea
Advantageous crystalline–amorphous phase boundary for water oxidation
Abstract: Development of efficient electrocatalysts for water oxidation, which is considered as the most sluggish reaction, is a challenge to overcome. Although novel metal based catalysts such as RuO2 are regarded as the best oxygen evolution reaction (OER) catalyst, their high-cost and comparatively lower long-term stability still limit the practical applications of water splitting. From this perspective, exploring non-novel-based catalysts with high OER performance is highly desired. Recently, we report that phase boundary between crystalline and amorphous of transition metal compounds plays an important role in boosting the OER catalytic activity. Also, increasing the density of crystalline-amorphous phase boundary further enhances the OER performance. Herein, a novel strategy to fabricate high-performance water oxidation catalysts via facile engineering of the crystalline–amorphous (c-a) interface is demonstrated. Also, the OER mechanism of the catalysts from experimental results combined with theoretical approach is discussed, which can give further insight into c-a interface engineering to improve OER performance.
2020 ECD Jubilee Global Diversity Award
Abstract: Multi-scale thermal protective systems for extreme environments: design, processing, properties and modeling
Thermal protective systems for hypersonic vehicles can provide additional strategies to survive the severe conditions they endure: large heat fluxes, extreme temperatures, extensive thermal gradients, stagnation pressures and oxidative environments. These components must meet these additional requirements: minimal material ablation, low overall weight, complex shapes, controlled dimensions tolerances and mechanical integrity for integration with other aircraft components. Multi-scale porous UHTCs with a suitable combination of microstructure (pore size, type and amount) and properties (thermal conductivity, pore network connectivity and thermomechanical response) may meet those requirements. However, deciding what that suitable combination of microstructure-properties is the real challenge.
In this work, a multi-faceted approach for design and manufacturing of multi-scale porous UHTCs is presented. Highly aligned porous channels are produced in titanium diboride using electrospun fibers as sacrificial fillers, with a multi-scale porosity between 50 and 80%, with controlled alignment to direct the flow of a second phase or divert the heat away by tailoring thermal conductivity. The microstructure and thermal and mechanical properties are characterized along and across the pores axis, and compare with analytical models. The results show that the manipulation of the highly aligned porous microstructure allow to control the thermal and mechanical properties as a function of the direction of the pores. Computational approaches are validated by experimental characterization of actual samples, as a pathway to develop predictive capabilities. This integrated combination of predictive modelling of porous UHTCs with tailored processing routes to create porous structures is key to match the desired performance.
valentina casalegno, Institute of Materials Physics and Engineering, Politecnico di Torino (POLITO), Italy
Ceramic and composite joints for nuclear applications
Abstract: The joining of ceramic based materials (bulk and composites) to themselves or to dissimilar materials (i.e metals) is a crucial point for nuclear energy applications, since their use is proposed in various advanced fission and fusion systems. In both cases, the main issues are the extreme thermo-mechanical loads on the joined components, the not completely known service conditions and requirements, their resistance to high temperatures, to ion/neutron irradiation and to harsh chemical environment.
An overview of the last 18 years of activity at Politecnico di Torino (Italy) on different joining materials (glass-ceramics, customized brazes, etc) and joining processes (pressureless methods, conventional brazing, direct bonding, etc) used to join ceramic–based materials for nuclear applications will be presented. The morphological and mechanical characterization of the joints will be discussed. The characterization of some proposed joining materials and of the joints in nuclear environment will also be presented: with the aim of reproducing a similar damage scenario to that in nuclear plants, some joining materials have been irradiated with different ions (He, Si) and with fission neutrons at different temperatures.
hui-suk yun, Korea Institute of Materials Science (KIMS), korea
Current technological advances in multi-ceramic additive manufacturing
Abstract: Additive manufacturing (AM) is a fabrication process that used digital information from a computer-aided design file to stack 2D layers of various materials to produce a 3D object, without requiring any part-specific tooling. AM technologies have attracted much attention in various fields such as medicine, automotive, aerospace, consumer, and other industrial applications. However, there are still limitations in both selection of materials as well as controlling part performance. In the former case, polymers and metals are typically used as materials for high precision AM whereas the technology for ceramics is comparatively inadequate yet. In the latter case, functionality of 3D structure was controlled only by designing 3D architectures, however we can expect much advanced functionality by using multi-materials for AM process. To this purpose, our group has developed a novel digital light processing for multi-ceramic additive manufacturing. The fabrication system and processing has been successfully optimized for various types of materials. We could co-print multi-component in one structure using less amount of ceramic slurry with high resource efficiency. We could control cross-contamination between multi components by adapting novel washing process. We believe that this new technology may provide big turning point to overcome limitation of traditional ceramic forming process.