Departmental news

· Flash sintering is a ceramic processing technique which uses electric current to intensively heat the ceramic sample internally rather than using only external furnace heating. The process can lower ceramic processing temperatures and durations significantly, enabling ceramics to be co-processed with metals or other materials, and reducing energy use.

· However, the process can result in low quality ceramics due to weaknesses caused by inhomogeneities in the microstructure.

· The origins of these inhomogeneities caused by thermal gradients in the material during flash sintering have been studied by researchers based at WMG, University of Warwick and academic and industrial collaborators, and routes to mitigate the effects of these gradients are outlined.

· Adopting these modified flash sintering routes will enable the wider use of flash sintering in ceramic processing, enabling lower energy production of many useful ceramic products including solid-state batteries.

Densifying ceramics using flash sintering reduces energy use and may be used to improve the viability of manufacturing complex ceramic structures such as those required for solid state batteries by lowering the temperatures and shortening the duration of the heat treatment.

Working in collaboration with academic and industrial partners, researchers from WMG, University of Warwick have published a review of the state of the art of flash sintering focusing on the formation of inhomogeneous regions within the ceramics which currently limit the scale-up potential of flash sintering. The review finds that thermal gradients are responsible for microstructural inhomogeneities and suggests of routes to eliminate or reduce these effects.

The reduction of energy use in the ceramic manufacturing industry is a key step in meeting global emissions reduction targets, as conventional processes require long firing treatments at very high temperatures. Several low-energy processes have been developed over the past decade, with flash sintering emerging as a particularly promising route for densification of materials for use in applications including solid state batteries, thermal barrier coatings, and ceramic joints.

In the paper, ‘Promoting microstructural homogeneity during flash sintering of ceramics through thermal management’ published as part of a special issue of the MRS Bulletin, Gareth Jones and Dr Claire Dancer from WMG, University of Warwick worked with collaborators from the University of Trento, Wuhan University of Technology, Normandie Université, and Lucideon Ltd to review the origins of microstructural variations in different regions of ceramic materials undergoing flash sintering.

Differences in microstructural development originate from thermal gradients within the material during processing, and these can be reduced by careful thermal management during the flash sintering process. These include:

· Altering the method for applying electrodes

· Improving thermal homogeneity through insulation

· Tailoring the frequency of the AC current

· Developing contactless methods for applying the electric current - which are currently limited to consolidation of thermal barrier coatings.

The findings of this review provide a roadmap for further research on thermal management in flash sintering, which will accelerate the development of the process for industrial implementation.

Dr Claire Dancer, leader of the Ceramics Group within the Materials and Sustainability Directorate at WMG, University of Warwick comments:

“Lowering ceramic processing temperatures by using techniques such as flash sintering is an essential step for manufacturing complex multi-material structures such as those needed for solid-state batteries, and for lowering overall energy use in the ceramic industry.

“However, the process must produce robust homogenous ceramic materials to be of widespread use. Our paper explains why flash sintering can result in inhomogeneous properties in ceramics and suggests a number of routes to mitigate these effects.”

ENDS

9 MARCH 2021

NOTES TO EDITORS

The work has been funded by an EPSRC New Investigator Award, a PhD studentship from ERDF and Lucideon, the Royal Society, and the High Value Manufacturing Catapult.

High-res images available at:

https://warwick.ac.uk/services/communications/medialibrary/images/march_2021/figure1.png
Caption: Causes and Effects of thermal and microstructural gradients in flash sintered ceramics.
Credit: WMG, University of Warwick

https://warwick.ac.uk/services/communications/medialibrary/images/march_2021/figure2.png
Caption: Microstructural development changes with different sintering approaches. Flash sintering produces fine microstructures with very high density with lower energy use than conventional approaches.
Credit: WMG, University of Warwick

https://warwick.ac.uk/services/communications/medialibrary/images/march_2021/figure3_png.png
Caption: Simulation of heat distribution during flash sintering.
Credit: WMG, University of Warwick

Paper available to view at: https://link.springer.com/article/10.1557/s43577-020-00010-2

For further information please contact:

Alice Scott
Media Relations Manager – Science
University of Warwick
Tel: +44 (0) 7920 531 221
E-mail: alice.j.scott@warwick.ac.uk

WMG Research Fellow, Dr David Fengwei Xie has been awarded a prestigious five-year EPSRC Early Career Fellowship.

Based in the International Institute for Nanocomposites Manufacturing (IINM), Dr Fengwei Xie has been working on sustainable polymer materials and composites for tackling the current issues around petro-derived plastics, recycling, and single-use plastics. His fellowship will allow him to further explore in this highly important area and to develop functional, biopolymer-based composite materials with tailored structures and properties for demanding applications.

The fellowship will provide his projects with sufficient funding and a dedicated team that will engage with the public, industry and policymakers.

An EPSRC Fellowship is designed to provide the recipient with the necessary support to establish or further develop themselves as a leader of the future. The award enables the recipient to devote their time to delivering their proposed research vision.

Dr Fengwei Xie explained: “The support provided by the EPSRC will allow me to develop my technical and transferrable skills to the greatest extent, become an independent and leading academic in advanced biopolymer materials engineering, and establish and grow my own group – fulfilling my career ambition.

“I am extremely excited to be awarded this fellowship as it will allow me to continue working on ‘green’ polymer composites for people’s welfare and a sustainable future.”

Read more about WMG’s Nanocomposites research here.

Solar thermal cells continue to attract much interest as they have massive potential to heat water in a cost-effective and sustainable process. To date, the efficiency of these cells has been limited as the polymers used in their manufacture are poor thermal conductors.

However, thanks to funding from BEIS (Department for Business, Energy & Industrial Strategy) a team of researchers led by Professor Tony McNally, from WMG, at the University of Warwick in partnership with Senergy Innovations Ltd have developed the first nanomaterial enabled all polymer solar thermal cell.

The thermal properties of the polymers employed are modified such that heat from sunlight can be transferred with high efficiency to heat water in a cheap and sustainable manner. The modular design of the cells allows for the rapid construction of a solar thermal cell array on both domestic and industry roofing.

The team are now working with a consortium of industry partners focused on manufacturing the solar thermal cells in high volumes.

Dr Greg Gibbons, at WMG, and his team have also produced the first prototype (1:1 scale) of the solar thermal cell fully manufactured by 3D printing. This activity has been transformative in guiding the design and critical aspects of the manufacture of the solar thermal cells.

Professor Tony McNally, Director of the International Institute for Nanocomposite Manufacturing (IINM), at WMG, University of Warwick comments:

“It is really pleasing to see several years of research activity and the understanding gained being translated in to a real world application. Our fundamental work on the thermal conductivity of 1D and 2D materials, including graphene, and composites of these materials with polymers could revolutionise the supply of affordable, clean and sustainable energy.”

Christine Boyle, CEO, Senergy Innovations Ltd. adds:

“Switching to advanced polymer materials meant a more efficient manufacturing process and more flexible product design. This resulted in the breakthrough of the low cost, low carbon, lightweight smart Senergy panels. Our job now is to ensure that Senergy solar panels become a key part of the smarter built environment and make renewable heating and cooling systems affordable and accessible for everyone.”

ENDS

15 OCTOBER 2020

NOTES TO EDITORS

High-res images available at:

https://warwick.ac.uk/services/communications/medialibrary/images/october_2020/tony_m_solar_cell_testing.jpg
Caption: The solar cell as it went in for testing
Credit: WMG, University of Warwick

https://warwick.ac.uk/services/communications/medialibrary/images/october_2020/christine_boyle.jpg
Caption: Christine Boyle, CEO of Senergy Ltd with the Solar Panel
Credit: WMG, University of Warwick

For further information please contact:
Alice Scott
Media Relations Manager – Science
University of Warwick
Tel: +44 (0) 7920 531 221
E-mail: alice.j.scott@warwick.ac.uk

WMG PhD student Chris Ellingford has been selected to attend the 8th Global Young Scientists Summit (GYSS) in Singapore from 14 to 17 January 2020.

Chris was one of only 300 participants, from across the world, and one of only five from the University of Warwick invited to attend.

GYSS gathers young researchers and scientists from across the world to encourage them to pursue their scientific ambitions. They have the chance to network with peers, as well as distinguished scientists and researchers.

The theme for this year’s event is "Advancing Science, Creating Technologies for a Better World,” with an impressive line-up of speakers including recipients of the Nobel Prize, Fields Medal, Millennium Technology Prize and Turing Award.

At GYSS Chris, as one of only 100 participants selected, will present at the poster session, and take part in lectures and panel discussions, and have the opportunity to interact with speakers in informal small group sessions. Outside of the Summit, Chris will also have the chance to visit local universities and research centres to learn more about Singapore’s research and innovation ecosystem.

Chris is currently in the 4th year of his Research Degree at WMG. He is based within the Nanocomposites team investigating "Self-healing Elastomeric Nanocomposites for Actuation and Energy Harvesting."

Professor David Mullins, Acting Head of WMG, was delighted to welcome Mr Li Dong, Executive Vice President of China Energy to WMG.

Mr Li Dong was accompanied by a senior delegation from China Energy and subsidiary companies China Shenhua Energy Co. Ltd - the largest coal company in the world, and Pujing Chemical Industry.

WMG’s Nanocomposites research team is currently working with colleagues at China Shenhua Energy Co. Ltd and Pujing Chemical Industry on the development of sustainable and environmentally friendly fully biodegradable plastics.

Dr Chaoying Wan and Professor Tony McNally updated the guests on the project, and the delegation toured other key WMG research facilities in Composites, Additive Layer Manufacturing (ALM), Metrology and Battery Technology.

Professor Tony McNally said: “At a time when the sustainability of single use plastics has become a global issue, the WMG partnership with China Shenhua Energy Co. Ltd and Pujing Chemical Industry is internationally leading. Our goal is to develop fully biodegradable plastics that decompose to benign components, such as water and, that can replace many of the single use plastics used in packaging.”

We are proud to announce that Professor Tony McNally has been selected by China’s Ministry of Education and State Administration of Foreign Experts Affairs under Plan 111 as a Foreign Expert to advise in the manufacture and characterisation of functional composite materials.

China’s Plan 111 is jointly organised by the Ministry of Education and State Administration of Foreign Experts Affairs, P.R. China. It aims to gather groups of first-class minds from around the world to work with leading Chinese researchers on the creation of 100 dedicated innovation centres.

Over the next 5 years Professor McNally will be working in collaboration with the International Innovation Centre for Advanced Manufacturing proposed by the School of Mechanical and Electrical Engineering, Beijing University of Chemical Technology (BUCT).

Professor Tony McNally, who heads up Nanocomposites research at WMG has been announced as the first Editor-in-Chief of the newly formed journal, Functional Composite Materials.

The Associate Editors and the Editorial Board, led by Professor McNally, include the leading academics in the field from around the world. The journal will consider contributions on all types of composite materials where composite functionality can be clearly demonstrated.

Functional Composite Materials is published by SpringerNature. The publisher producers a number of key research journals and books globally on science, technology, medicine, humanities and social sciences.

Patients at risk of heart attacks and strokes may be spotted earlier thanks to a diagnosis tool that uses near-infrared light to identify high-risk arterial plaques, according to research carried out at WMG, University of Warwick, the Baker Institute and Monash University.

The scientists observed that when they increased the wavelength of the light currently used to visualise the fatty build-up found in arteries (atherosclerotic plaques) they could selectively identify the rupture-prone deposits, which commonly lead to blood clots, heart attacks and strokes.

Inspired by the materials that helped astronauts survive Apollo 11’s mission to the moon, Professor Tony McNally has focused his career on developing new composites based on nano materials. WMG’s Professor McNally, who is based at the International Institute for Nanocomposites Manufacturing (IINM), was recently interviewed for Reinforced Plastics (www.reinforcedplastics.com), below is a snapshot of his thoughts on the challenges facing his research field.

While my research is rooted in fundamental engineering science, the target is functional composite materials that can be readily manufactured into products in high volumes.

Professor Tony McNally, Dr Chaoying Wan, and Dr Lukasz Figiel will be representing WMG at the 2^nd Sino_UK Bilateral Symposium on Polymer Nanocomposites with a series of lectures from 27-30 October.

The conference will take place at Donghua University in Shanghai, China, and will bring together experts from around the world.

Professor McNally will act as a Co-Chair for the four day event alongside representatives from Shanghai Jiaotong University and Donghua University. Professor McNally will also be delivering his own seminar on 28 October entitled ‘Electrical and Rheological Percolation of Composites of Polymers and MWCNTs’.

Also on 28 October, Dr Chaoying Wan will deliver ‘Dispersion and Interphase of Polymer Nanocomposites’ and Dr Lukasz Figiel ‘Prediction of Overall Behaviour of Polymer Nanocomposites Via Multi-Scale Modelling’.

International Institute for Nanocomposites Manufacturing (IINM) at WMG

Nanocomposites research within IINM encompasses both fundamental and applied research, associated with the manufacture of novel materials, devices and components with tailored functionality and properties. For more information visit warwick ac.uk/wmgresearch/nano