A New Understanding of Electrochemical Processes and Microstructure in Engineering Alloys with Correlative Microscopy
Professors Barbara Shollock (Warwick Manufacturing Group) & Patrick Unwin (Chemistry)
University of Warwick, UK
Controlling the corrosion of metallic alloys is a critical issue in a range of sectors and applications – implants in medicine, reinforcing bars in construction, and body and chassis in vehicles – in terms of aesthetics, performance and structural integrity. Engineering alloys such as alloy steels, stainless steels, and aluminium and titanium alloys can fail by stress corrosion cracking. Stress corrosion cracking involves simultaneous interaction of metallurgical, environmental and mechanical factors. Three basic mechanisms of stress corrosion cracking have been identified: active path dissolution, hydrogen embrittlement and film-induced cleavage. These mechanisms vary depending on the alloy, environment and stress conditions and are highly localised (see images). Much more information is needed on the electrochemical and chemical processes involved at the local level and how this relates to microscopic structure. This PhD will address this aim and set a new course for studying corrosion through the use of innovative methods.
We seek a holistic view of stress corrosion cracking, using a range of complementary multi-length scale (nano to macro) experimental techniques to characterise the microstructure and electrochemical processes that result in stress corrosion cracking. Experimental studies will be underpinned by mass transport and reaction modelling. Innovative electrochemical imaging approaches pioneered at Warwick, and gaining global attention (see: http://pubs.acs.org/doi/abs/10.1021/acs.langmuir.6b01932) will be combined with advanced microstructural characterisation techniques (SEM, TEM, EBSD). The example above shows how these latter advanced techniques capture local stresses to correlate with the electrochemical data.
This multidisciplinary PhD will provide a unique and exciting opportunity to obtain fundamental insight into the mechanisms of stress corrosion cracking and the influence of metallurgical, environmental and mechanical factors. The project is expected to be of high impact and to provide the student with an opportunity to learn a wide range of important scientific and other skills and to have hands on access to state of the art microscopy facilities. It further provides an opportunity to work between 2 leading groups at the University of Warwick that are growing a new activity at the Chemistry-Engineering interface, including work with industry partners. In addition to publishing in top journals, there will be opportunities to present the work at international conferences.
We welcome applications from science graduates with at least a II.i BSc (or BEng) degree or good Masters degree. The project is open to UK/EU applicants. UK candidates are eligible to receive a full stipend (grant) and fees (EU applicants fee support).
Interested applicants should send their CVs to:
B.Shollock@warwick.ac.uk and P.R.Unwin@warwick.ac.uk