Experimental Mechanics of Advanced Materials
Experimental Mechanics of Advanced Materials
We are an experimental characterization group with unique capabilities to understand the damage and fracture of advanced materials under extreme conditions over multiple length-scales.
It is essential to gain a mechanistic understanding of failure in materials, to make an informed choice on how material properties can be improved to survive harsh environments such as irradiation, extreme high/low temperatures, and hydrogen exposure. This characterisation is key for industrial applications like nuclear fission/fusion reactors and aerospace fuel systems, at present and in the future.
The materials of interest to EMAM include:
- Carbon/graphite
- SiC/SiC
- Oxide/Oxide
- TRISO fuel particles/compacts
- Novel nuclear fuel cladding materials
- MAX phases.
- Aerospace alloys (steels, nickel-based superalloys)
Novel and cutting-edge techniques have been developed and used to study these materials over multiple length scales. These include frequency-domain thermoreflectance (FDTR), electron channelling contrast imaging (ECCI), neutron diffraction beamline experiments, Raman spectroscopy, and cryogenic mechanical testing. We correlate nano- and micro-structure due to materials processing with macro-scale damage and fracture from in-service conditions. EMAM uses rigorous scientific approaches to gain a mechanistic understanding of failure modes in materials exposed to extreme environments, underpinning their subsequent industrial applications.
EMAM has formed strong collaborative ties with key national and international players in the nuclear fission, nuclear fusion and aerospace fields, such as EDF, UKAEA, UK NNL and Rolls-Royce plc, and are keen to continue collaborations with current and new industrial partners.
We have active ongoing projects in the following areas with open DPhil and Postdoctoral opportunities. In addition, we are interested in hosting undergraduate summer placements within the group. Please contact us if you interested in learning more.
Mechanistic Understanding of the Damage and Fracture in Ceramic-Matrix Composites under Extreme Conditions
Working with many industries and processing groups, this area studies a range of aerospace and nuclear fission/fusion CMCs in terms of their local mechanical and thermal properties, residual stresses, deformation and fracture including crack initiation and propagation from ambient to temperatures higher than 1000°C with in situ imaging and diffraction methods.
Damage and fracture in nuclear graphite composites over multiple length-scale
This topic studies a large range of polycrystalline graphite materials, from highly oriented pyrolytic graphite to fine/medium/coarse grained graphite composite, unirradiated or irradiated with ions, neutrons or protons, to understand their multiple length-scale structure, physical properties before and after irradiation, at ambient and up to 1100°C.
Thermal and mechanical characterisation of TRISO fuels: This programme investigates a range of Tristructural Isotropic nuclear fuel particles (TRISO), both free-standing or embedded in SiC or graphite matrix, in terms of their local properties, residual stresses and high temperature mechanical properties changing with processing parameters.
Interfacial strength of heterogeneously integrated ceramic films
A range of micro-mechanical testing methods have been developed to evaluate the interfacial toughness of thin ceramic films (e.g., GaN) integrated on stiff substrate including SiC, Si and single/polycrystalline diamond, with the aim to enable the development of novel semiconductor materials for high power radio frequency (RF) devices.
Funding sources: EPSRC, STFC, BEIS and various UK and US industrial funding