Latest Papers

Evolution of intragranular stresses and dislocation densities during cyclic deformation of polycrystalline copper
J Jiang, TB Britton, AJ Wilkinson
Acta Materialia (2015) vol. 94, 193-204

The effect of pattern overlap on the accuracy of high resolution electron backscatter diffraction measurements
V Tong, , J Jiang, AJ Wilkinson, TB Britton
Ultramicroscopy (2015) available on line

Using transmission Kikuchi diffraction to study intergranular stress corrosion cracking in type 316 stainless steels
M Meisnar, A Vilalta-Clemente, A Gholinia, Michael Moody, AJ Wilkinson, N Huin, S Lozano-Perez
Micron (2015) vol. 75, 1-10

The orientation and strain dependence of dislocation structure evolution in monotonically deformed polycrystalline copper
J Jiang, TB Britton and AJ Wilkinson
International Journal of Plasticity (2015) vol. 69, 102-117

A synchrotron X-ray diffraction study of in situ biaxial deformation
DM Collins, M Mostafavi, RI Todd, T Connolley and AJ Wilkinson
Acta Materialia (2015) vol. 90, 46-58

A discrete dislocation plasticity study of the micro-cantilever size effect
E Tarleton, DS Balint, J Gong, and AJ Wilkinson
Acta Materialia (2015) vol. 88, 271-282

ESRF April 2015 team photo

Experiment at ID11 ESRF
We were fortunate to get allocated 18 shifts (6 days) of beamtime at ID11 ESRF. Hamid Abdolvand who had drafted the proposal led the team consisting of Jicheng Gong, Dave Collins, Yi Guo. Jon Wright (centre of photo) provided tremendous support both in the lead up to the experiment and during it. The team successfully ran a series of 3D XRD measurments during in situ tensile testing of Ti and Zr samples. With help from Wolfgang Ludwig some diffraction contrast tomography scans were also conducted taken at the start and and of the deformation experiments. Hamid will be kept busy with data analysis for a considerable time.

Dislocation Dynamics embedded in FEA
Ed Tarleton in collaboration with Daniel Balint (Imperial College) have successfully embedded discrete dislocation dynamics simulations of plasticity within a finite element analysis framework that handles complex displacement and traction boundary conditions. This new modelling capability is an important tool for analysis of small scale mechanical testing experiments. Micro-cantilever bend tests on hexagonal Ti and Zr crystals conducted by Jicheng Gong have been simulated. The marked size effect, stochastic flow behaviour, and slip band spacing evident in the experiments are all well captured by the simulations. The study is reported in Acta Materialia

DDD-FEA modelling
slip band-GB interaction

DPhil Studentships Available
There are two funded DPhil projects available within the group for October 2015 start. Both concern micromechanical aspects of deformation and fatigue in Ti alloys. The first concentrates on continuing developent and application of small-scale ultrasonic testing for high cycle fatigue. The other will continue a successful vein of work using HR-EBSD and other methods to study slip band – grain boundary interactions. Both projects will involve collaboration with Rolls Royce and link into activiities on the HexMat Programme grant. Unfortunately funding is restricted to UK and EU citizens.
'Further Details'

Meet us at

ICM12 2015
12th Int Conf on Mechanical Behaiour of Materials

KIT, Germany, 10–14 May 2015
- Junnan Jiang will be presenting on micromechanical testing of grain boundary sliding

ICMM 2015
4th Int Conf on Material Modeling

Berkeley CA, 27–29 May 2015
- several members of the group will be attending and Hamid A will be presenting

M and M 2015
Microscopy and Microanalysis 2015

Portland, OR, 2-6 August 2015
- presentations by Angus W on 'progress with EBSD strain mapping', and Arantxa V-C on 'EBSD strain mapping in III-V nitride' and on 'Transmission Kikuchi Diffraction'

Int Conf on Strength of Materials 2015

Brno, Czech Republic, 9–14 August 2015
- several members of the group will be attending and hopefully presenting talks and posters

ECI nanomechanics
Nanomechanical Testing of Materials V

Albufeira, Portugal, 4-9 October 2015
- Angus W and Jicheng G will be attending and presenting talks/posters