Order-Disorder Transformations: Introduction and Nomenclature

This lecture introduces the concept of ordering states in simple cubic and hexagonal structures, discussing the enthalpy of mixing, ordered states in binary alloys, GP-zones, and ordered structures at simple stoichiometries. It also covers the transformation from B-brass to its ordered low-temperature structure, emphasizing the importance of diffusion and nucleation. The instructor explains the salient features of ordered states, highlighting the structural changes in different lattice types and the role of preferential bonds and interplanar distances in stabilizing the structures.