Crystallography of precipitates in Mg alloys

Crystallography of precipitates in Mg alloys is indispensable to explain and predict alloy microstructures and properties. In order to obtain a global understanding of diversified experimental results, a general theory of singular interface is introduced, which provides the physical base and calculation methodology for interpreting precipitate morphology and orientation relationship (OR), especially useful for understanding irrational facets and ORs. Guided by the theory, recent experimental findings are systematically summarized, including thermally stable and metastable precipitates with various crystal structures. Then, theoretical advances inspired by the findings are introduced, which deepens our understanding on OR selection and preference of irrational facets. At last, future research directions in this field are proposed.