In situ Characterisation of the Mechanical Behaviour of Energy Materials under Extreme Conditions
材料学院青促会学术交流报告
Dr.
Dong Liu Department of Materials University of Oxford
Title: In
situ
Characterisation of the Mechanical Behaviour of Energy Materials under Extreme
Conditions
地点:浙江大学玉泉校区曹光彪楼326会议室
时间:2017年07月18日(星期二)
10:00
邀请人:秦发祥
材料学院青年教师发展促进会承办
Abstract:
Materials
with multiple
length-scale structures
are a fascinating yet critical class of material that have characteristic
dimensions spanning from nano- to
macro-scales. These materials have enormous potential for nuclear and energy
applications as they can display unique properties such as combinations of
strength and toughness at ambient to elevated temperatures.
Taking
nuclear-grade graphite as an example, which is a porous
graphite composite
used as the moderator and major structural component in UK power reactors, I
will talk about mechanical testing under two extreme conditions: fast
neutron irradiation
and elevated
temperatures
(1000°C) using in situ micro-mechanical testing inside a
scanning electron microscope and in
situ high
temperature 3D X-ray computed tomography, respectively. It was found that this
material displays unusual higher strength and fracture toughness at elevated
temperatures due to the relaxation of residual stresses.
Further
examples on the failure modes of several ceramic-based
composites
tested in
situ at
elevated temperatures up to 1200°C will be covered briefly.
Brief
Bio:
Dr.
Dong Liu is currently a EPSRC (Engineering and Physical Sciences Research
Council) Research Fellow, Royal Commission for the Exhibition of 1851 Brunel
Research Fellow, and Mansfield College Junior Research Fellow at the University
of Oxford (UK), and a research affiliate to the Lawrence Berkeley National Lab
(USA). She obtained her Ph.D. at the University of Bristol (UK) in 2012 on the
measurement of residual stresses and mechanical properties in environmental and
thermal barrier coatings. She then worked as a postdoctoral researcher on the
deformation and fracture of quasi-brittle materials such as cement, gypsum
plaster composites and nuclear graphite before moving to Oxford.
Her
current project is to challenge the in
situ
mechanical testing on nuclear and energy materials at multiple length-scales
(from micro- to macro-size), and under extreme conditions such as irradiation
and elevated temperature. The materials of interest include graphite materials
and carbon composites, ceramic-based composites, MAX-phase ceramics,
environmental and thermal barrier coatings, nano-structured steels and GaN-diamond
composite materials for electronic devices.
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