Tension–compression Creep Asymmetry in Strong-Textural Mg-RE Alloy Due to Dislocation Reconfiguration

Strong-textural Mg-RE alloy exhibits creep asymmetry at 200 degrees C, with a much higher creep resistance in compression than in tension, albeit a higher yield strength in tension than in compression. Creep asymmetry is ascribed to the non-Schmid effects of pyramidal slip, which enables a higher friction in compression and thus induces a lower mobility of pyramidal slip in compression than in tension. Additionally, the dissociation of dislocations into sessile structures in compression is more frequent than in tension, which contributes to the hardening response and thus lowers the compressive creep rate. [GRAPHICS] . MPACT STATEMENTA new mechanism of the dissociation behavior difference of pyramidal slip and its non-Schmid effect accounts for the creep asymmetry in highly textural Mg alloys.