Development of crack tip plasticity in steels

Description

Next Generation Nuclear is a partnership between the Universities of Lancaster, Leeds, Liverpool, Manchester and Sheffield. Its mission is to develop the next generation of research leaders to support the UK’s present and future strategic nuclear programmes- cleaning up the nuclear legacy, building new nuclear power stations, and defence and security. It will work with all the UK’s major industrial and regulatory stakeholders, including Amec, Areva, AWE, EDF, the Nuclear Decommissioning Authority, the National Nuclear Laboratory, Rolls-Royce, and Sellafield Ltd, and with leading overseas institutions.

Very recently, it has been demonstrated that metal fatigue in aerospace alloys can be detected using optical second harmonic generation. Second harmonic generation or frequency doubling occurs when photons interact with a non-linear material and are combined to produce new photons with twice the energy and hence twice the frequency and half the wavelength of the original photons. In this research, second harmonic generation was found to occur at material interfaces associated with dislocations in the material’s atomic structure that accumulate and coalesce into cracks. In particular, polarisation measurements were markedly different in the plastic zone ahead of a crack tip compared to virgin areas of the material, which implies that second harmonic polarisation analysis could be useful in non-invasive analysis of fatigue cracks. In this project, the technique will be extended to steels used in reactor pressure vessels with a view to elucidating our understanding of the development of the crack tip plastic zone during the load cycling. This will involve identifying the characteristics of polarisation second harmonic generation associated with fatigue damage in steels and establishing portable instrumentation that will allow in-situ measurements during fatigue tests. Comparison of the resultant measurements will be made with existing techniques, such as thermoelastic stress analysis and scanning electron microscopy.

We welcome applications from graduates who have, or expect to obtain, a good degree (first class or upper second).

For further details and to apply contact Eann Patterson (eannp@liverpool.ac.uk). Also see https://realizeengineering.wordpress.com/tag/myresearch/

To apply for this opportunity, please click here.  

Availability

Open to EU/UK applicants

Funding information

Funded studentship

To be eligible for a studentship, you must either be a U.K. citizen or a European Union national who has been resident in the U.K. for at least 3 years prior to starting the course. We welcome applications from good students of all nationalities, but we are only able to offer financial support to students that fulfil the above criteria.

The NGN Centre welcomes applications from international students however; this particular programme is funded by the Research Council which means we have limited funding opportunities for overseas students.

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