Project title: Corrosion scale dynamics
Supervisors: Prof. Nicholas Harrison (Chemistry), Prof. Michael Finnis (Materials, Physics)
The presence of solid corrosion products, forming thin films or “scales” on the metal surface, can lead to the reduction of the corrosion rate. A fundamental understanding of the formation, stability and growth of these thin films is vital for the oil and gas field equipment sustainability. The corrosion process involves multiple time and length scales, and constitutes a formidable challenge for modelling approaches.
My work focuses on developing a model for describing the growth of thin films, as a function of time and the electrochemical environment. Planar film growth usually involves transport of ions and electrons through the film to sustain growth. A model for films with columnar grain structure has been proposed and within this 3D structure, grain boundary transport of charged point defects, electrons and holes, is studied as a function of the environment. The arising system of transport and Maxwell’s equations is solved numerically. This model, with a 3D grain boundary structure, a time dependent treatment of the transport through the film, and an explicit calculation of the Coulomb interaction of the mobile charged species, is going beyond current analytic or numerical models, which often only consider the steady state limit and commonly assume homogeneous films.
The project is partly funded by BP and part of BP’s International Centre for Advanced Materials (project BP-ICAM08). It involves a collaboration with experimentalists from Dr Robert Lindsay’s group at Manchester University.