Dr James Zhijian Shen is an expert in ceramics science and engineering, specializing in designing and synthesising of
advanced ceramics and composites with tailored microstructures and chemistry for structural and functional applications.
He holds a position as a Professor, Noble Biocare Chair of Materials Innovation, at Arrhenius Laboratory, Stockholm University,
where he also serves as an area manager of Biomaterials in the Berzelii Center EXSELENT on Porous Materials strategically supported
by the Swedish Governmental Agencies VR and VINNOVA. He has authored more than 200 published papers on ceramics and ceramic processes.
He was educated in China, received his PhD on Materials Physics and Chemistry in 1990 and was appointed as an Associated Professor in
1992 at Zhejiang University. In 1993, he moved to Sweden, initially as a postdoctoral researcher, latterly was appointed as a senior
researcher, Associated Professor and Professor in the same Institution he has always been working till now.
His Topic of Materials' Days 2010:
Micron-defects mask the potentials of nanoceramics:
Microstructural defects in micron-scale are not intrinsic features of nanoceramics. They are types of processing defects introduced
during ceramics processes. Once formed, they are inheritable, i.e. they are carried on during the processes and remain in sintered
bodies thus to impair the performances of nanostructured ceramics that otherwise would be enhanced by their nano-sized grain structure
and/or associated high interface content. In most of the cases, micron-defects are already formed during the powder forming or powder
granulation processes, with more addition during the green body forming processes. Sintering can hardly completely heal micron-defects
even under pressure, with increased challenge when rapid sintering techniques are employed for densification. In general, it is much
more difficult to handle the micron-defects in nanoceramics due to the inherent large sintering driving forces associated with the
nanoparticles. In this presentation examples will be given to classify the types of micron-defects encountered during the processing
of nanoceramics. The influence of micron-defects on various performances of nanoceramics will be discussed. Ways and means of avoiding
and destroying micron-defects during the entire ceramic processing cycle will be suggested in order to explore the full potentials of