New approach to probing localised corrosion processes over wide length and time scales using integrated multi-scale electrode arrays

Highlights: • New approach to probing localised corrosion at different spatial and temporal scales. • Variously designed and patterned electrode arrays are used to probe localised corrosion. • Electrode arrays provide unique insight on different stages of localised corrosion. • Smaller sized electrode arrays reveal early stage corrosion initiation activities. • Current maps measured from different sized electrode arrays reveal different information. Electrochemically integrated multi-electrode arrays are variously designed for probing complex localised corrosion initiation and propagation processes occurring over different spatial and temporal scales. Electrode arrays made of 100 μm and 1 mm diameter aluminium alloy AA2024-T3 wires were used to illustrate the probing of submillimetre and millimetre scale localised corrosion processes over heterogeneous metal surfaces, while a patterned electrode array was employed to probe co-operative corrosion occurring across different metallurgical and microstructural features. The combined use of variously designed and patterned electrode arrays and surface analytical techniques is shown to provide unique insights into different stages of localised corrosion on heterogeneous alloy surfaces.