Understanding Corrosion and Passivation Processes in Light Alloys using Multinuclear NMR Techniques: A Visiting Fellowship for Prof. M. Forsyth

Lead Research Organisation: University of Birmingham
Department Name: Metallurgy and Materials

Abstract

This is a proposal for a 4 month visiting fellowship for Prof. Maria Forsyth of Monash University to visit the UK to carry out exploratory work on the use of nuclear magnetic resonance (NMR) to investigate the corrosion and passivation of aluminium and magnesium. She will be based in the Department of Physics at Warwick with Prof. Mark Smith (NMR), but also make frequent visits to Birmingham only 20 miles away to work with Dr Alison Davenport (corrosion) and Dr Melanie Britton (magnetic resonance imaging, MRI). Forsyth is without doubt an acknowledged world-leader in materials engineering, particularly related to polymer electrolytes, novel ionic electrolytes and electrochemical corrosion processes. This project will focus on the use of NMR techniques to study the corrosion and protection of light alloys based on magnesium and aluminium. The chemistry of protective passivating films will be determined with multinuclear NMR techniques to investigate the mechanism of formation and the way in which they block corrosion reactions. When corrosion does take place, corrosion pits penetrate into the metal. NMR will be used to determine the chemistry of the concentrated metal chloride solutions within these pits, and the transport of water and even ions that control pit stability. Finally, the possibility of using magnetic resonance imaging to observe the development of artificial pits will be explored. Very preliminary measurements have suggested that this challenging experimental approach is feasible, and could open up an entirely new approach for the study of pitting processes. In addition to exploring new experimental approaches to corrosion and passivation of metals, this work will develop a fundamental understanding of these processes that will be of practical value to the aerospace and automotive industries, where light alloys such as magnesium and aluminium are being increasingly used to improve fuel efficiency, and efforts are underway to extend the lifetime of structures (for example ageing aircraft). In such applications, corrosion and its prevention are critical to the safety of vehicles. This project will bring together a group of researchers with highly complementary expertise to develop NMR techniques, to include spectroscopy, relaxation, diffusion and imaging experiments to bring a novel approach to using magnetic resonance techniques to probe corrosion and passivation processes in light metal alloys. During the fellowship, the intention is to bring together the world-leading material's expertise of Forsyth with the NMR and materials expertise of the UK team to form a long-term collaboration between the UK and Australia that will make a unique contribution to this field. This will be an intensive burst of activity to kick start this new project. In addition, this will be an excellent opportunity for Prof. Forsyth to meet a range of other UK groups during her stay and to give a series of colloquia.

Publications

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Britton MM (2013) In Situ, Real-Time Visualization of Electrochemistry Using Magnetic Resonance Imaging. in The journal of physical chemistry letters

 
Description This grant provided funds for Professor Maria Forsyth (Monash University, now Deakin University, Australia) to spend a sabbatical at the Universities of Warwick and Birmingham, carrying out research in solid state NMR (Warwick) and MRI (Birmingham). The research carried out in Birmingham demonstrated, for the first time, the ability to use MRI to image solution species around metal electrodes undergoing electrochemical reactions. The system studied was the galvanic corrosion of zinc in a concentrated chloride solution, and changes in the characteristics of water around the corrosion products were mapped. This proof-of-concept experiment has shown that it will be possible to investigate a number of electrochemical systems, for example those involved in batteries, corrosion, and metal finishing, including electroplating. There has been extensive characterisation of metal electrodes during such processes, but very limited focus on the electrolyte side of the interface, and MRI offers an excellent opportunity to provide a rich level of information on solution behaviour. During these processes, the rate of reactions and corresponding changes in the electrodes themselves are often sensitive to species present and rates of transport in the electrolyte. MRI allows these to be visualised in 3D in real time with resolution on the scale of tens of microns and flow and diffusion coefficients. This will improve understanding of these processes and provide a route for evaluating modifications to existing technologies as well as the development of new ones.
Exploitation Route The approach demonstrated in the project has the potential contribute to the development of industrial processes: it may be possible to image devices such as small batteries. There are a number of companies working in areas such as metal finishing, and a number of these provided letters of support for a subsequent grant that was submitted to EPSRC to follow up this work. Preliminary discussions are being held with a company with interests in corrosion to explore future collaborative work, and similar approaches to battery companies are envisaged.
Sectors Aerospace, Defence and Marine,Chemicals,Energy

 
Description Leverhulme Grant
Amount £149,951 (GBP)
Funding ID RPG-2013-222 
Organisation The Leverhulme Trust 
Sector Charity/Non Profit
Country United Kingdom
Start 02/2014 
End 01/2017