Engagement

Porous ceramics and composites – from processing to simulation

Wednesday, April 10th 2019
Sparck Jones Building SJG/11
11:15 

Abstract. Cellular materials offer a wide spectrum of applications such as catalyst support structures, lightweight materials, energy adsorption or energy storage materials. Due to several ways of processing and different materials, a wide range of material properties e.g. thermal conductivity, mechanical strength or damping can be adjusted, measured and verified, with regard to the expected properties. Various techniques for processing porous ceramics and composites independent of material are presented. Especially in heterogeneous and homogeneous porous structures and their composites, only global effective material properties can be determined and measured. Knowledge on the predominating influence of the microstructure on the global properties is the key for designing materials with desired properties. To fill this gap and enable a "look-in" a model of microstructure derived from µCT measurements carried out at certain processing steps can be used as model for FEM-calculations. Combining estimated material properties by experiment with models of microstructure offers the possibility to carry out different simulations over different hierarchical levels. In contrast to experiments, also the pore network or the composite network and their influence on global parameters can be analysed. This approach is carried out on different cellular structures and composites (see Figure 1).

Figure 1: a) Pore network of a 30ppi replica foam, b) FEM-simulation of stress distribution in a MAX-phase gelcasted foam, and c) scaffold of hydroxyapatite building blocks and epoxy resin for block fixation. 

All welcome to attend 

Enquiries to v.vishnyakov@hud.ac.uk

Latest references:

Stumpf, M., Fan, X., Biggemann, J., Greil, P., Fey, T. Topological interlocking and damage mechanisms in periodic Ti₂AlC-Al building block composites, Journal of the European Ceramic Society (2019) 39(6), pp. 20032009, https://doi.org/10.1016/j.jeurceramsoc.2019.01.047

Biggemann, J., Pezoldt, M., Stumpf, M., Greil, P., Fey, T. Modular ceramic scaffolds for individual implants, Acta Biomaterialia 80 (2018) 390–400, https://doi.org/10.1016/j.actbio.2018.09.008

 Fey, T., Stumpf, M.,  Chmielarz, A., Colombo, P., Greil, P., Potoczek, M. Microstructure, thermal conductivity and simulation of elastic modulus of MAX-phase (Ti₂AlC) gel-cast foams , Journal of European Ceramic Society 38 (10)  (2018) 3424-3432, https://doi.org/10.1016/j.jeurceramsoc.2018.04.012

 Biggemann, J., Diepold, B., Pezoldt, M., Stumpf, M., Greil, P., Fey, T. Automated 3D assembly of periodic alumina-epoxy composite structures, Journal of American Ceramic Society 101 (10) (2018) 3864-3873 https://doi.org/10.1111/jace.15586        

Simulating materials for fusion and fission

Wednesday, November 29th 2017
Sparck Jones Building SJ3/19
14:15 

Abstract. Finding structural materials that can cope with the hostile environment of fusion and fission power plants is a famously difficult problem. In this talk I will describe work carried out over a number of years to understand some properties of defects in ferritic steels, and more recently in zirconium. Attention will be given to the computer models used, which are mostly quantum mechanical, and to the difficulties of capturing the important contribution made by magnetism and non-adiabatic effects.

Biography.  Andrew Horsfield joined the Materials Department at Imperial College in 2007 as an RCUK Fellow, is an honorary Research Fellow at the London Centre for Nanotechnology and a member of the Thomas Young Centre. His current research interests cover the dynamics of electrons out of equilibrium, and the thermodynamics of complex interfaces. Previous to this he was the Senior Research Fellow in charge of the theory core project for the IRC in Nanotechnology at UCL where he developed a novel scheme for non-adiabatic molecular dynamics (Correlated Electron-Ion Dynamics).

His interest in the interface between biology and physics was made possible by a Career Development Fellowship from the Institute of Physics which he received while working for the Fujitsu European Centre for Information Technology. His interest in efficient electronic structure methods and the development of two electronic structure codes (Plato and OXON) occurred while working in the Department of Materials at Oxford University with Prof. David Pettifor and Prof. Adrian Sutton. This built on his experience with tight binding while studying liquid silicon with Prof. Paulette Clancy at Cornell University as a PDRA and Junior Lecturer. He obtained his PhD in Physics from Cornell University.

All welcome to attend 

Enquiries to v.vishnyakov@hud.ac.uk