Deformation of multiphase materials: Experiments and numerical modelling (EPSRC DTP)

Supervisor(s)

Professor Sandra Piazolo and Professor Rik Drummond-Brydson

Contact Professor Sandra Piazolo (S.Piazolo@leeds.ac.uk) to discuss this project further informally.

Project description

This exciting project aims to shed light on the long standing problem of how multiphase materials behave during deformation and how the deformation history influences material behaviour during subsequent deformation.

This project is unique as it aims to capitalize on the knowledge base and experimental capabilities that are available in both materials science and geoscience research. In this innovative project you will use cutting-edge analytical and experimental techniques and combine results using novel numerical simulations.

Outcomes promise to be of high impact in both materials science and geoscience. Recently the search for new, high performance materials has expanded to multiphase materials, including metal matrix composites, superalloys and two-phase alloys.

At the same time, in the earth sciences there is an urgent need to understand in depth the rheological behaviour of multiphase materials such two to three phase rocks as these constitute the majority of rock on Earth (Buergmann & Dresen 2008).

In both disciplines, there is a need to develop an in-depth understanding of the processes ongoing during deformation, so that we can predict future material behaviour. However, currently, there is still a lack of understanding how different phases that react differently to stress and strain will influence each other during deformation.

In addition, the effect of the presence of different phase on the resistance of stress corrosion cracking is not well established. At the same time, in geoscience, we need to understand not only the flow properties of rocks at depth at high pressures and temperatures but also importantly the link of the high temperature ductile flow with that of lower temperature brittle failure.

Hence, investigating the link between ductile-brittle deformation during and after deformation is pivotal to our understanding of both industrial materials and earth system science. Processes that we need to understand include crystal plastic flow, twin generation and deformation, recrystallization processes including nucleation of new grains, recovery and grain boundary migration as well as fracture generation and propagation.

For high strain deformation, generation of nanocrystalline materials and their evolving properties is important. Importantly, we need to understand the generation of local high stress and strain heterogeneities arising from a rheologically heterogeneous material. At the same time, since the materials investigated are not simple in their chemical composition, not only the physical rearrangement of grains needs to be understood but also the chemical changes that go hand in hand with such deformation processes.

Objectives: This project aims to achieve a new level of understanding and quantification of the underlying principles governing deformation of multiphase materials. Three main questions will be addressed:

1) Processes: What physiochemical processes occur at different conditions of formation and deformation? How do the physical processes govern the chemical processes and vice versa?

2) Effect: How do these processes effect the rheological behaviour of the investigated material during deformation and after deformation?

3) Prediction: Based on the resolution of the two questions above, what are our possibilities to (a) predict material behaviour to allow development of new high performance multiphase materials and to (b) predict the behaviour of geological materials through time and pressure-temperature space.

Key benefits

Potential for high impact outcome Outcomes of this project promise to be of high interest to both the material science and the geoscience community. The strength of the project lies in the combination of techniques allowing theory development and benchmarking of numerical models against nature and experiments. Interestingly, nature produces a large variety of different “processing” scenarios, hence we can learn from nature without having to do a large array of physical experiments. Results will be used to develop novel, high performance materials important to industry, and will inform large scale numerical simulations predicting earth movement through time, including the possible generation of hazards such as earthquakes.

Entry requirements

Applications are invited from candidates with or expecting a minimum of a UK upper second class honours degree (2:1) or equivalent, and/or a Master's degree in the relevant subject area.

The candidate should have a strong interest in deformation mechanisms and recrystallization processes, experimental work and combining this with numerical simulations.

The candidate should have the desire to undertake a study crossing the disciplinary boundaries between materials science of manufactured and natural materials (e.g. rocks).

A strong background in a quantitative science concerned with material properties and optimization (earth sciences, physics, materials science, surface chemistry) is essential. A Masters degree in a related subject will be advantageous.

If English is not your first language, you must provide evidence that you meet the University’s minimum English Language requirements.

How to apply

Formal applications for research degree study should be made online through the university's website.

If you require any further information, please contact the Graduate School Office e: apply-phd@see.leeds.ac.uk, or t: +44 (0)113 343 1634.

We welcome scholarship applications from all suitably-qualified candidates, but UK black and minority ethnic (BME) researchers are currently under-represented in our Postgraduate Research community, and we would therefore particularly encourage applications from UK BME candidates. All scholarships will be awarded on the basis of merit.