Abstract:

Magnesium alloys, known for their low density and high strength-to-weight ratio, are increasingly important in the aerospace and automotive industries. Understanding the static recrystallisation (SRX) behaviour of these alloys is crucial for optimizing their mechanical properties and manufacturability. This seminar will explore the fundamental mechanisms of SRX in magnesium alloys via using quasi-in-situ electron backscattered diffraction (EBSD), focusing on the microstructural evolution during annealing post-deformation. We will discuss the influence of nucleation site, alloying elements, initial grain size, and deformation conditions on the kinetics of recrystallisation. Recent advancements in Electron Backscatter Diffraction (EBSD) techniques have significantly enhanced our ability to collect large datasets with high acquisition speeds, enabling the scanning of large areas. However, post-data processing remains challenging and time-consuming when extracting quantitative and statistical results simultaneously. This seminar will also introduce our newly developed Track-Rex toolbox (https://github.com/TrackRex/Track-Rex), which allows the automatic tracking of thousands of grains and summarising the customised results within a few hours. These findings and new insights will offer a comprehensive overview of the evolution of recrystallisation grains throughout the entire SRX process and help us tailor the microstructure

Brief Biography:

Dr Dikai Guan is an Associate Professor from the University of Southampton. He is also a UKRI Futurer Leaders Fellow and is a recognised leading early career researcher in developing new alloys, tailoring microstructure and designing pertinent experiments for microstructure characterisation, with a strong publication track record. He pioneered the design of in-situ casting to produce pore-free bulk nanostructured Mg alloys with ultra-high strength and good ductility. He established systematic recrystallisation mechanisms and proposed novel deformation behaviour in Mg alloys. He recently developed a Track-Rex toolbox, allowing researchers to track the grain growth behaviour of many thousands of grains individually and obtain statistical results simultaneously. Due to his recognition in electron backscattered diffraction (EBSD) research field, he was selected to be the scientific organiser of a highly reputed national EBSD annual meeting organised by Royal Microscopical Society in 2021. He is currently working closely with TWI and Luxfer companies, aiming to convert light alloy machining chips into bespoke wire products, and he is committed to deliver impact from his research focusing on sustainable materials development and circular economy. Moreover, he is also working with international collaborators for employing novel solid-state additive manufacturing to process Mg and Al alloys. He has published around 20 peer-reviewed papers in high impacted journals including Nature, Acta Materialia, Scripta Materialia and Acta Biomaterialia,