Twinning in Hexagonal Close-Packed Materials: The Role of Phase Transformation

Twinning is a major mechanism of plastic deformation in hexagonal close-packed (hcp) structures. However, mechanistic understanding twin nucleation and growth has yet to be established. This paper reviews the recent progress twinning hcp materials—particularly newly discovered phase transformation-mediated mechanisms—in terms crystallographical analysis, theoretical mechanics calculations, numerical simulations. Moreover, relationship between mechanisms dislocations are presented, forming unified twinning. Finally, this also studies on transformation twins that formed martensite microstructures after various transformations, highlighting critical role mechanical loading engineering microstructure.