(DTP EPSRC) Microstructure crack-growth relationships in Ti6Al4V

Titanium alloys are used extensively in the manufacture of aero-engine components, owing to their exceptional strength and relatively low density. These alloys owe their exceptional properties to their structure at the microscopic scale, the microstructure, which can be controlled during alloy processing and component manufacture. 

One of their important properties of these alloys is their resistance to fatigue strength, that is, failure after repeated loading cycles, where the stress in the material is well below its yield strength. Although the stresses are very low, some of the crystals making up the alloy can deform and eventually introduce damage and eventually failure.

Through extensive testing, engineers have developed sound empirical relationships between fatigue crack growth rate and the microstructure of different Ti alloys. However, the actual physical mechanisms controlling this behaviour are not fully understood. This gap in our knowledge makes it difficult to account for material and/or operating conditions outside previous experience. It also makes it difficult to understand how the alloys could be improved, so that less of it can be used, which would help build lighter, more efficient aero-engines.

The aim of this project is to better understand fatigue crack growth rates in Ti64 microstructures containing microtextured regions, including the effects of cold creep(dwell). The approach is to characterise the crack path, study crack tip plasticity and relate it to the material microstructure (including microtexture). This will be supported by crystal plasticity modelling of the deformation ahead of the crack tip.

The research program will include:

 – Study of the micromechanics ahead of crack tips in Ti64 using HRDIC

 – Characterisation of crack path using X-ray tomography

 – Characterisation of crack path using 3D EBSD

 – Correlative microscopy of crack path and microstructure

 – Crystal plasticity modelling of crack tip plasticity

The successful candidate will join a large team of researchers (10+) working on titanium alloys at Manchester, and collaborate with scientists and engineers at Rolls-Royce and other UK universities. The project provides access and training on some of the most advanced characterisation methods currently available and sound training in advanced data analysis using open source packages. There will also be opportunities to visit Rolls-Royce and other partner organisations.

Entry requirements

This project ideally suits a materials science graduate, although physics and mechanical engineering graduates would also make strong candidates. No previous research experience is needed, however experience with using computers to analyse and solve problems, in particular using Python and Matlab, would be beneficial

How to apply

You will need to submit an online application through our website here: https://uom.link/pgr-apply

When you apply, you will be asked to upload the following supporting documents: 

• Final Transcript and certificates of all awarded university level qualifications

• Interim Transcript of any university level qualifications in progress

• CV

• You will be asked to supply contact details for two referees on the application form (please make sure that the contact email you provide is an official university/ work email address as we may need to verify the reference)

• Supporting statement: A one or two page statement outlining your motivation to pursue postgraduate research and why you want to undertake postgraduate research at Manchester, any relevant research or work experience, the key findings of your previous research experience, and techniques and skills you’ve developed. (This is mandatory for all applicants and the application will be put on hold without it.

• English Language certificate (if applicable). If you require an English qualification to study in the UK, you can apply now and send this in at a later date. 

Before you apply

We strongly advise you to contact the supervisors.

Equality, diversity and inclusion is fundamental to the success of The University of Manchester, and is at the heart of all of our activities. We know that diversity strengthens our research community, leading to enhanced research creativity, productivity and quality, and societal and economic impact. We actively encourage applicants from diverse career paths and backgrounds and from all sections of the community, regardless of age, disability, ethnicity, gender, gender expression, sexual orientation and transgender status.

We also support applications from those returning from a career break or other roles. We consider offering flexible study arrangements (including part-time: 50%, 60% or 80%, depending on the project/funder). 

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