Evolution of the Microstructure of Polycrystalline Magnesium at Mega Plastic Deformation in Bridgeman Anvils

Abstract

The method of transmission electron microscopy is used to study the evolution of polycrystalline magnesium structure after shear under high pressure at room temperature. In the initial deformation stages (shrinkage), band structures are observed. It is established that after shear at 5°, the predominant deformation mode is twinning in the (I0Ī2) plane. For shear at 90°, electron microscopic cells, grains with enhanced level of internal stress, and small fraction of recrystallized grains and fragments are distinguished. For high deformation degrees (1–5 revolutions), uniformly distributed recrystallized grains and fragments are observed, and basal deformation structure is clearly distinguished by the radiographic method.