Visualization and validation of twin nucleation and early-stage growth in magnesium. Academic Article uri icon

abstract

  • The abrupt occurrence of twinning when Mg is deformed leads to a highly anisotropic response, making it too unreliable for structural use and too unpredictable for observation. Here, we describe an in-situ transmission electron microscopy experiment on Mg crystals with strategically designed geometries for visualization of a long-proposed but unverified twinning mechanism. Combining with atomistic simulations and topological analysis, we conclude that twin nucleation occurs through a pure-shuffle mechanism that requires prismatic-basal transformations. Also, we verified a crystal geometry dependent twin growth mechanism, that is the early-stage growth associated with instability of plasticity flow, which can be dominated either by slower movement of prismatic-basal boundary steps, or by faster glide-shuffle along the twinning plane. The fundamental understanding of twinning provides a pathway to understand deformation from a scientific standpoint and the microstructure design principles to engineer metals with enhanced behavior from a technological standpoint.

published proceedings

  • Nat Commun

author list (cited authors)

  • Jiang, L., Gong, M., Wang, J., Pan, Z., Wang, X., Zhang, D., ... Schoenung, J. M.

complete list of authors

  • Jiang, Lin||Gong, Mingyu||Wang, Jian||Pan, Zhiliang||Wang, Xin||Zhang, Dalong||Wang, Y Morris||Ciston, Jim||Minor, Andrew M||Xu, Mingjie||Pan, Xiaoqing||Rupert, Timothy J||Mahajan, Subhash||Lavernia, Enrique J||Beyerlein, Irene J||Schoenung, Julie M

publication date

  • January 2022