About the Project
The 7xxx series Al alloys are the most commonly used material in aircraft structural applications due to their high strength and low production costs. However, these alloys exhibit an increased susceptibility to Environmentally Assisted Cracking by hydrogen embrittlement that can result in their premature failure. The effective management of this issue is, thus, an area of growing concern for the aerospace industry. Research in hydrogen embrittlement is a dynamic field, with our current understanding constantly being challenged by new developments. Despite extensive work, there is still a critical need for creative solutions to overcome this issue.
A key issue in understanding and effectively managing hydrogen embrittlement is identifying and exploiting the rate-determining bottleneck in the evolution of damage. In microstructurally complex Al alloys, this kinetic process is influenced by stress gradients in the material, as well as microstructural trapping sites such as precipitates, grain boundaries, dislocations and vacancies. Thus, hydrogen resistance can be improved through a careful control of these various factors. While, current approaches achieve this to a certain extent through alloying and heat treatments, the precise nature of the microstructure-hydrogen interaction remains unclear.
Through using a coupled chemo-mechanical modelling approach, this project will aim to provide a key understanding and knowledge of the kinetic microstructural effects that result in hydrogen embrittlement. The transport mechanisms for hydrogen at the microstructural scale will be investigated systematically by varying alloy composition and processing conditions. In this way, the role of precipitates, crystalline defects, chemical segregation and mechanical loading in determining the local hydrogen fluxes will be identified. This understanding will be used to develop improved strategies for hydrogen management through controlled alloying and precipitation.
The project is fully supported by Airbus, a leading pan-European international company. The student will be given the opportunity to spend time within Airbus, to attend meetings and workshops with their technical experts, as well as to gain an understanding of their commercial operation. The PhD Project will be based in the Airbus Centre of Metallurgical Excellence, a joint initiative between Airbus and Manchester University which will develop to become a group of ~ 15 researchers. Airbus also holds an annual student conference to facilitate networking amongst their PhD students spread across Europe.
Advanced Metallic Systems Centre for Doctoral Training
The Advanced Metallic Systems CDT is a 4 year programme hosted jointly by the universities of Manchester and Sheffield building on their complimentary expertise and international reputations in materials science and engineering research. In year 1, students from a range of disciplinary backgrounds undertake taught courses in core materials topics. PhD research begins after 6 months. Our transferable skills and personal development programme leads to a Diploma in Professional Skills. Visit our website for more information www.metallicsCDT.co.uk.
Funding Notes
Applicants should have or expect to obtain a first class, upper second class or postgraduate masters degree (Merit or above) in Physics, Mechanics or Materials Engineering, with strong results in the theoretical and modelling components of the degree. Please contact us if you wish to discuss your suitability for the programme.
The four-year studentship includes tuition fees and a minimum stipend of £16,777pa, supported by Airbus and the Engineering and Physical Sciences Research Council.