{101¯2} twinning nucleation in magnesium assisted by alternative sweeping of partial dislocations via an intermediate precursor

Abstract

Molecular dynamic simulation and transmission electron microscopy (TEM) characterization was employed to investigate the {101¯2} twinning mechanism in magnesium. A partial dislocation assisted twinning nucleation mechanism was proposed based on simulation results, in which the twin lattice was reconstructed from parental matrix by two-step sweeping of partial dislocations on different close packed planes from matrix and the subsequently formed twin precursor respectively. A {101¯2} twin precursor was observed adjacent to matrix/twin interface by a spherical aberration corrected TEM, which indicated the hexagonal-close-packed (hcp) matrix→quasi face-centered cubic (fcc) twinning precursor→h.c.p twin transformation sequence during {101¯2} twinning process.

Keywords

• Magnesium
• Twinning
• Basal slip