Phase Transformations in Al-Cu Alloys: Microstructure and Kinetics

This lecture discusses the binary Al-Cu system, focusing on equilibrium and non-equilibrium structures. It covers solidification processes, including microsegregation and the effects of cooling rates on microstructure. The instructor explains the significance of phase transformations, emphasizing the kinetics involved in these processes. Key concepts include the role of dislocations, the impact of grain size on mechanical properties, and the mechanisms of structural hardening. The lecture also addresses the importance of heat treatment for homogenization and the dissolution of phases within the alloy. Various diagrams, including phase diagrams and TTT diagrams, are presented to illustrate the relationships between temperature, time, and phase transformations. The instructor highlights the practical implications of these transformations on the properties of Al-Cu alloys, including ductility and strength. The discussion concludes with insights into the challenges of achieving uniform microstructures and the strategies employed in metallurgical processes to optimize alloy performance.