Processing

Processing

Grasso (QMUL) Densification and texturing of ceramics for extreme environments; Feb 2013 – Jan 2018: A 5 year programme aimed at extending SPS to densify existing materials with ultra-high melting points and produce new materials. The focus is also on understanding the effect of electric fields and current on the microstructure and properties of the materials and controlling the microstructure (in terms of grain size, texturing and morphology) by modulating the intensity of the electromagnetic field. Cash and in-kind contributions have been received from a range of organisations, including Transport for London (London Underground), Kennametal UK, Element Six and Harbin Institute of Technology in China. Both a world-leading facility and a world-leading position have been achieved, a UK patent on flash sintering applied for and proof-of-concept Follow Up Funding has been awarded. A list of more specific achievements was provided on p 2 of this document.

Saunders (QMUL) Unconventional electric field-assisted ceramics processing; Sep 2013 – Aug 2016: A leveraged PhD programme funded by QMUL and the EC, the latter via the ADMACOM FP7 project (2007-2013). The work is focused on understanding and hence clarifying the electric field contribution to the densification process obtained during spark plasma sintering (SPS), with Saunders also contributing to the ADMACOM project which is aimed at joining advanced ceramics using SPS, a topic very relevant to XMat. The research has used optical emission spectroscopy to identify whether or not plasma is formed during the sintering of ceramics and a new sintering technique has been developed based on a contactless flash sintering method.  More recently attention has been focused on methods to arrest oxidation in UHTCs by preventing oxygen ion diffusion through the oxide scale via the application of an electric field. This latter has been particularly successful and oxide scale growth has been reduced by ~800% via the application of a very small electric field.