ŠEDÁ Petra Fyzikální ústav AV ČR, v.v.i.

Spoluautoři JÄGER Aleš, LEJČEK Pavel

Continuous dynamic recrystallization (CDRX) plays an important role in the deformation of magnesium, particularly at a deformation at moderate temperatures (~200-250°C). The CDRX is characterized by formation of dislocation walls due to dislocation accumulation and gradual increase of their misorientations resulting in the formation of high angle boundaries. In the present paper, magnesium single crystals were processed by a single pass via equal channel angular pressing (ECAP) at 230°C in order to examine the dynamic recrystallization behavior. Application of the single crystals offers to investigate the formation of new grain boundaries via CDRX from the boundary-free structure. Microstructure and microtexture were investigated by scanning electron microscope equipped with electron backscattered diffraction camera. The deformed microstructure was heterogeneous, composed of deformed (but unrecrystallized) and recrystallized zones. Furthermore, it was found that twinning plays an important role during ECAP processing. Formation of differently shaped and oriented dislocation walls is discussed as well as the character of high angle grain boundaries occurring in recrystallized zones.

Zpět