Advances in Powder and Ceramic Materials Science: Poster Session
Sponsored by: TMS Extraction and Processing Division, TMS Materials Processing and Manufacturing Division, TMS: Materials Characterization Committee, TMS: Powder Materials Committee
Program Organizers: Bowen Li, Michigan Technological University; Shefford Baker, Cornell; Kathy Lu, University of Alabama Birmingham; Faqin Dong, Southwest University of Science and Technology; Jinhong Li, China University of Geosciences; Eugene Olevsky, San Diego State University; Ruigang Wang, Michigan State University; Dipankar Ghosh, Old Dominion University
Monday 5:30 PM
February 28, 2022
Room: Exhibit Hall C
Location: Anaheim Convention Center
Session Chair: Kathy Lu, Virginia Polytechnic Institute and State University; Dipankar Ghosh, Old Dominion University
F-13: Atomistic Modeling of Hot-press Sintering of AlN Nanoceramics: Aoyan Liang1; Chang Liu1; Paulo Branicio1; 1University of Southern California
We use molecular dynamics atomistic modeling to study the hot-press sintering of AlN nanoceramics. Samples composed of nanoparticles with 8, 12, and 16 nm diameters are employed: namely, samples AlN-8, AlN-12, and AlN-16. Simulations are run for 6 ns under a 1 GPa hydrostatic pressure and 1,900 K temperature. An extra simulation is performed for an 8 nm sized nanoparticle system at a lower pressure of 0.1 GPa (sample AlN-8-0.1). Results show that the AlN-8 sample reaches 99% densification, the highest of all systems. 96.2%, 95.6%, and 93.2% densification is achieved for the samples AlN-8-0.1, AlN-12, AlN-16, respectively. Results reveal a two-stage sintering process: (1) Initial swift densification that is rooted at the high diffusivity of surface atoms. (2) Intense grain growth driven by grain boundary migration. These results offer nanoscale insights on the intriguing hot-press sintering of nanoscale ceramics and shed light on the densification and microstructural evolution processes.
F-14: Determining the Processing Conditions for Fe Metal Exsolution and Phase-decomposition of Doped CaTiO3 for Catalysis Applications: Jason Luong1; Komal Syed1; William Bowman1; 1University of California, Irvine
Exsolution of transition metals from perovskite oxides has allowed the development of robust and durable oxide-supported metal catalysts without complex synthetic processes. By producing catalytically active nanoparticles that are partially submerged, or anchored, in the surface of the perovskite oxide supports, the exsolution mechanism has proven to be a viable strategy for stable catalyst synthesis. In the past, the perovskite CaTiO3 has been studied to understand its mixed ionic-electronic conductivity and exceptional structural integrity with high defect concentration. As a means to synthesize a composite material fully composed of highly abundant elements, Fe-doped CaTiO3 was selected and found experimentally to undergo a thermo-chemical process in a reducing environment to facilitate a phase-decomposition mechanism. In this work, to understand the microstructural changes during phase decomposition and exsolution, X-ray diffraction, scanning electron microscope, and energy dispersive spectrometry are used to observe the composition and phases at the micro and nanoscale.
F-15: Incorporation of Ornamental Stone Waste into Red Ceramics: Mariane de Aguiar1; Monica Gadioli1; Francisco Vidal1; Kayrone de Almeida1; 1CETEM
Brazil is one of the largest producers and exporters of ornamental stones in the world. The state of Espírito Santo stands out as a national production and export hub. Its use in civil construction demands processes of unfolding the blocks into sheets. This process is responsible for generating a large amount of waste. For this reason, the incorporation of waste into red ceramics has been researched in the search for an environmentally correct destination for waste, in addition to enabling the use of an alternative raw material for the ceramic industry. Bibliographic research was carried out regarding the use of waste from the processing of ornamental stones, where works were selected, for a presentation of the studies and results obtained in research carried out in recent years. The results showed that addition of ornamental stone waste for red ceramic fabrication is feasible and improves ceramic properties.
F-16: Microstructure and Mechanical Properties of Mechanically Alloyed and Spark Plasma Sintered NbC-Ni Cermets: Supreeth Gaddam1; Surekha Yadav1; Amit Behera2; Qiaofu Zhang2; Fan Meng2; Noriaki Arai2; Zaynab Mahbooba2; Rajiv Mishra1; 1University of North Texas; 2QuesTek Innovations LLC
Mechanical alloying followed by spark plasma sintering (SPS) or pressure less sintering were used to prototype various NbC-Ni cermet compositions. The effect of various process parameters related to the ball milling and sintering processes on the final microstructure and mechanical properties of these NbC-Ni cermet compositions were evaluated. Further, based on the experimental observations, computational modeling tools were used to predict changes in the microstructure and properties for the NbC-Ni system in general. The goal of this effort was to narrow down on the right composition and process parameters that would work for prototyping a suitable cermet to be used to make friction stir welding (FSW) tools to process high-temperature materials. A systematic investigation has been carried out on the NbC-Ni system to gain a better understanding of the processing-structure-property relationship and lay a foundation for developing novel cermet-based tools for FSW.
F-17: Participation of Nitrosamide in the Selective Catalytic Reduction of Nitrogen Oxides over Cu/SSZ-13: Anna Getley1; Furio Corà1; Jasper Berry-Gair1; Chu Lun Alex Leung1; 1University College London
Cu/SSZ-13 is a promising ceramic for the reduction of nitrogen oxides (NOx) - released from diesel exhausts - into water and nitrogen. However, feasibly incorporating this catalyst to an industrial standard requires a full understanding of the complex reaction mechanisms. This computational work utilises Density Functional Theory to calculate equilibrium geometries and activation barriers, revealing NOx reduction half-cycle pathways over Cu/SSZ-13 with nitrosamide intermediates. The results indicate that water and ammonia ligands, previously regarded as copper-bound spectator species, instead actively influence the nitrosamide dissociation in two ways. Firstly, coordination environments determine the molecular orbital binding, affecting the N-O dissociation barrier. Secondly, the reaction is facilitated by a water or ammonia shuttle molecule at higher coordination numbers, consequently indicating a mechanism shift at lower ligation, correlating to a reduced catalytic activity. We therefore propose molecular design rules, motivated by ligation control, to systematically increase deNOx efficiency over Cu/SSZ-13.
F-19: Purity Improvement According to Batch and Continuous Hot Chlorination Processes of Natural Quartz Powder: Jong Ho Kim1; 1Rist
Natural quartz powder is the main ingredient in the crucible of solar and semiconductor silicon monocrystal growth. In general, natural quartz powders are manufactured through crushing and acid leaching processes using quartzite as the starting material. To achieve better purity, chlorine gas can be used at high temperatures to reduce the content of alkali element impurities. In this work, we compare the degree of purity improvement by applying batch and continuous processes. The batch process is easy to implement in a simple way and has the advantage of being easy to control purity, while the continuous method has the advantage in terms of productivity. In this work, we propose an optimal process variable to obtain improved purity when applying each process. Finally, quartz glass was manufactured through a melting process and its properties were verified as a product.
F-20: Technological Behavior of Ceramics Incorporating Powdered Waste from Ornamental Stone: Maria Angélica Sant'Ana1; Mônica Gadioli1; 1CETEM
The use of industrial waste for the production of civil construction inputs has been studied in order to contribute to sustainability, so the objective of this work is the use of waste from the processing of ornamental stones with a multiblade gang saw in the production of ceramic pieces. The raw materials used were: ceramic mass and waste from ornamental stone processing. Specimens were prepared for testing with incorporation of 0, 10, 20 and 30% of waste by mass. The specimens were formed by uniaxial pressing and sintered at temperatures of 950 °C and 1050 °C. Technological tests of flexural strength, apparent porosity, water absorption and linear shrinkage were performed. The results obtained in the study were promising and corroborate previous research showing that the use of waste can contribute to improvements in ceramic properties and promote sustainable development.
F-22: Three-dimensional Interconnected Porous Titanium Dioxide Ceramic for High-temperature Thermal Storage: Siyi Zhao1; Jinhong Li1; 1China University of Geosciences, Beijing
Porous titanium dioxide ceramic (PTC) with uniform, controllable, 3D fully interconnected pore structure and high porosities were prepared by a facile particle-stabilized emulsion templating method, and adjustable pore structure of PTCs could be obtained by controlling its solid content from 20 to 35 wt. %. Specifically, PTC was featured by large cavities connected by small-sized windows on the wall. The large cavities endow the PTC with large capability for impregnating PCMs, and the small windows make the leakage of impregnated PCM difficult. Moreover, its strength and porosity can be tailored. The study showed that the three-dimensional interconnected tailored pore structure and high porosities had positive effects on improving the thermal storage capacity and thermal properties of PCMs, PTC is a promising carrier material for High temperature energy storage.