Understanding the Impact of Friction Stir Welding Parameters on Precipitation Processes in Aluminium Alloys

Aluminium alloys are traditionally strengthened by nanometer-sized precipitates. Friction stir ;welding (FSW) is solid state joining process that is found suitable to join aluminium alloys as ;it overcomes the issues associated with fusion welding of such alloys.

This project investigates ;the impact of FSW parameters on precipitation processes in aluminium alloys, focusing on the ;interplay between extreme thermomechanical conditions encountered during FSW and ;microstructural evolution. The research will explore mechanisms such as continuous and ;discontinuous recrystallisation, heterogeneous precipitation of second-phase particles, and the ;transition between metastable and stable phases.

Emphasis will be placed on understanding ;how variations in welding parameters influence grain structure, precipitation behavior, and ;final mechanical properties. A major focus of the work will be on understanding the evolution ;of the microstructure and precipitates employing advanced characterization tools such as high ;resolution transmission electron microscopy (HRTEM) and atom probe tomography (APT) and ;small-angle scattering.