Electron-Microscope Studies of Deformed Mg

Abstract

The distribution and behaviour of dislocations, and also the fine structure of mechanical twin in magnesium deformed at room temperature were studied by means of the transmission electron microscopy. The most striking feature of dislocations in deformed magnesium was that the dislocations piled up toward the grain boundary. Besides this, the entangled dislocations were found along the twin boundaries. From these phenomena, some inferences are made as to the probable trend of the work-hardening of polycrystalline magnesium deformed at room temperature. Evidence was found for the occasional separation of perfect dislocations into partial ones separated by a stacking fault. However, the loops of prismatic dislocations containing a stacking fault probably originated in the precipitation of vacancies could not be found even in magnesium severely deformed at room temperature and quenched magnesium.