Influence of adhesion and friction on the geometry of packings of spherical particles

International audienc

Analysis and simulation guided processing of hierarchical porous and multi-layered ceramics

International audienc

Simulation of the toughness of partially sintered ceramics with realistic microstructures

International audienceIncreasing the pore volume fraction of porous ceramics enhances their functionality for a wide range of applications. However, the increased functionality comes at the expense of their toughness. Discrete element method (DEM) three-dimensional simulations, which operate at the length scale of individual particles, are used to investigate the toughness of microstructures typical of partially sintered ceramics. The method is first validated by comparing DEM simulations to the linear elastic fracture mechanics elastic solution at the crack tip of a pre-cracked numerical sample. The toughness of realistic random microstructures is then obtained using DEM simulations and compared to experimental data. Green density is shown to have a significant effect on toughness. Discrete simulations also suggest that the linear relationship between toughness and Young's modulus is primarily linked to the size of the solid necks formed during sintering of particle

Discrete element simulation: modeling sintering at the particle length scale

International audienc

Evolution of defects during sintering – discrete element simulations

International audienc

Preface for the special section of the JACerS on sintering. Editorial

This special section of the Journal of the American Ceramic Society includes a number of papers presented at the International Conference on Sintering 2017, which was held in San Diego, USA, on November 12‐16, 2017. The meeting was chaired by Professors Rajendra K. Bordia, Eugene A. Olevsky, Didier Bouvard, Suk‐Joong L. Kang, and Bernd Kieback. This was the eighth meeting in a series that started in 1995 as a continuation of the well‐known cycle of conferences on sintering and related phenomena organized by G. Kuczynski which ran from 1967 to 1983. The first seven meetings in this re‐established series of conferences were held at Pennsylvania State University, USA in 1995, 1999 and 2003; in Grenoble, France in 2005; in San Diego, USA in 2008; in Jeju Island, South Korea in 2011, and in Dresden, Germany in 2014. Sintering 2017 brought together more than 240 participants from 29 countries, fostering a high level of scientific interaction and creating an atmosphere of broad international collaboration. The meeting included participants from North and Central America, Europe (both Eastern and Western), Asia, Australia, and Africa. The conference demonstrated the advances that have been made in the areas of the modeling of sintering phenomena at multiple scale levels, including the fundamentals of microstructure development, and promoted a better understanding of the processing of complex systems (nanostructured, multi‐layered, composite, and reactive systems). Concerning sintering technology, innovative approaches such as field‐assisted sintering and application of sintering in additive manufacturing attracted the attention of the materials processing community. This collection of papers published in the special section of the Journal of the American Ceramic Society cover the rich diversity of the sintering science and technology topics presented at the conference. They focus on leading developments in sintering science and technology in both powder metallurgy and ceramic processing. In addition to selected papers presented at the Sintering 2017, this issue contains other papers on sintering since it is such an important topic in ceramic science and the technology of processing ceramics. We are thankful to the authors and reviewers of these papers who had to meet strict deadlines to enable the timely publication of this special issue of the Journal of the American Ceramic Society. We also thank William Fahrenholtz, Editor‐in‐Chief of the Journal of the American Ceramic Society; Jonathon Foreman, Managing Editor; Michelle Martin, Publication Services Specialist; and Greg Geiger, Technical Content Manager from the Technical Publications Office of the American Ceramic Society for working with us in development and production of this special issue. We hope the articles in this special section will be a significant addition to the scientific and technical literature on sintering and microstructure development, and we are looking forward to seeing you at future Sintering conferences

Densification and Microstructural Development in Anisotropic and Hierarchical Porous Ceramics

International audienc

Dispersion, connectivity and tortuosity of hierarchical porosity composite SOFC cathodes prepared by freeze-casting

International audienceAqueous co-dispersions of Lanthanum Strontium Manganite (LSM) and Yttria-Stabilized Zirconia (YSZ) were freeze-cast and partially sintered, resulting in anisotropic, hierarchically porous composites for potential applications as solid oxide fuel cell (SOFC) cathodes. The uniform phase dispersion was validated using SEM-EDS and FIB-SEM tomography. Using reconstructed 3D images of samples sintered at 1200 and 1300 C, the effect of sintering on phase connectivity, triple phase boundary (TPB) density and phase tortuosity was explored. The higher sintering temperature resulted in lower TPB density and, less open pore volume but decreased tortuosity for both the LSM and YSZ due to densification of the structure at high temperatures. Due to the unique double-sided morphology of the freeze-cast walls and the benefits gained from less tortuous percolation paths, a decrease in TPB density and open porosity from elevated sintering temperatures may not degrade the electrochemical performance as much as it would for a standard isotropic microstructure