This project sits within the EPSRC Centre for Doctoral Training (CDT) in Advanced Metallic Systems – a research centre formed by a partnership between the Universities of Sheffield and Manchester and the I-Form Advanced Manufacturing Centre, Dublin. Our doctoral students undertake a different doctoral programme, which includes a compulsory intensive technical and professional skills training programme throughout the 4-year project. For more information on our training programme content, aimed at converting graduates from a non-materials topic into metallurgy, please review the website.
This project is sponsored by STFC and involves a collaboration with the ISIS Neutron and Muon Source, supervised by Dr Lewis Owen in the Department of Materials Science and Engineering at the University of Sheffield. It is anticipated that the PhD candidate will spend two years (Years 2 and 3 of the project) working at the ISIS facility, allowing close collaboration with scientists at UK national research facilities.
The recent advent of compositionally complex materials such as high-entropy alloys, which contain five or more elements in near-equiatomic proportions and exist in simple crystal structures, has reinvigorated questions about interactions on the atomic scale (local structure) within metallic systems and the effect on observed physical properties. Total scattering, a type of advanced diffraction technique, is rapidly becoming a widely recognised technique for analysis of complex systems, and has provided great insight into the local structural properties in many interesting systems such as glasses, functional oxides, metal organic frameworks etc.
Of great interest to the metallurgical community is the ability to study materials in-situ, in environments that are capable of capturing conditions experience during operation. As many of these materials are required for structural purposes, the ability to explore them under stress conditions is particularly important for the understanding the structure-property relationships in these materials. For example, it has long been suggested that there is a link between short-range order (local preferred configurations of atoms) and alloy strength. However, current observations of SRO influencing strength are often indirect, and involve post-hoc measurements of phenomena such as dislocations. To answer these significant metallurgical questions, requires the ability to perform in-situ stress measurements on a diffractometer capable of obtaining total scattering data.
This PhD project will look at examining local structural phenomena under applied stress conditions. This project will involve both the examination of particular materials of interest, and the development of an in-situ rig suitable for performing these measurements on the Polaris diffractometer at the ISIS Neutron and Muon Source. Metallurgical samples will be prepared at the University of Sheffield, including powder manufacturing methods, and characterisation of the samples by scanning and transmission electron microscopy. Total scattering data will be acquired at the ISIS Neutron and Muon source, and complementary X-ray data at the Diamond light source. Analysis of these data will be carried out using RMCProfile and PDFGui, as well as developing bespoke analysis code. Tensile testing will be carried out on samples both in-situ and ex-situ. This project would suit a good Materials Science, Chemistry or Physics applicant.
Please send informal enquiries about the project to Dr Lewis Owen atĀ lewis.owen@sheffield.ac.uk
For more information and to apply visit https://www.findaphd.com/phds/project/phd-in-in-situ-tensile-compression-total-scattering-measurements/?p154401