Diffraction Research in Engineering and Advanced Materials

                    Former members
Diffraction research group is part of Solid Mechanics and Materials Engineering
at the Department of Engineering Science, University of Oxford:

Current Research Projects include:

High Engergy X-ray (HEX) Diffraction

Synchrotron particle acceleration is an excellent way to produce some high energy X-rays.

The basics of synchrotron light generation are explained in Alexander's short note on the subject.

We use synchrotron beamlines at the SRS Daresbury Laboratory and the European Synchrotron Radiation Facility, ESRF, in Grenoble.

Examples of detailed experimental strain mapping are shown in the figures below: (a) a region near the end of a TIG weld pass in an Al alloy plate, and (b) strain intensification around a crack traversing a four-point bent bar.

(a) (b) 

(AM Korsunsky et al. @ ESRF)

Laboratory surface X-ray Diffraction

Laboratory X-ray diffraction is an important tool for phase, texture and stress characterisation in a variety of practically important situations. The photograph shows one of the panels from the fuselage of Russian Tupolev-154 civil aircraft, which were removed during refurbishment after 11, 15 and 20 years of service. We considered the degradation of strength due to a combination of corrosion and fatigue in a study which drew on unique data obtained from coupons. Along with electrochemical properties, residual stresses, peak broadening and polar density variation of different reflections were considered as a function of depth, number of flights, and time of service. A new view was developed of the chemical/structural interactions during combined corrosion and fatigue.

Neutron Diffraction

(AM Korsunsky et al @ ISIS, RAL)

The combination of highly penetrating white neutron beam and the servohydraulic INSTRON loading rig on ENGIN allowed us to carry out in situ fully reversed fatigue cycling experiments. Our aim was to inivestigate the difference in the cyclic response of differently oriented groups of grains. The figure clearly demonstrates the importance of such insight for design against failure: while the 111 trace is given by a virtually straight line, the 200 shows significant deviation from linearity, caused by large plastic strain experienced by these grains.

Selected publications:

You can download a pdf copy of references showing the pdf logo .

This page was last modified on 20 August 2008.

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