Dynamic recovery around deformation kink boundary of Mg-Y-Zn alloy with long-period stacking ordered structure

This study demonstrated the possibility of dynamic recovery by forming a kink boundary in the long-period stacking ordered phase of the Mg85Y9Zn6 (at%) alloy. The compressive deformation at 1 % strain on the double-notched directionally solidified specimen produced three regions; undeformed, deformed, and kinkdeformed regions. A nanoindenter was applied to three different regions. The deformed region sufficiently far from the kink boundary exhibited a 26 % higher nanoindentation hardness than the undeformed region owing to work-hardening, whereas the hardness decreased when approaching the kink boundary. At 1 mu m or less from the kink boundary, the magnitude of hardness recovered to the same level as the undeformed region. This observation implies a "recovery kink zone" because of the dynamic recovery associated with kink boundary formation.