Tensile deformation of a Mg-2.54Nd-0.26Zn-0.32Zr alloy at elevated temperature

摘要

The engineering stress versus engineering strain curves for a Mg-2.54Nd-0.26Zn-0.32Zr cast alloy were measured by Gleeble-1500D thermo-simulation machine in the temperature range of room temperature to 400 A degrees C at initial strain rates of 10(-4)-10(-2) s(-1). The effects of strain rate on stress, elongation to facture, and section shrinkage were analyzed. The fractograph morphologies were investigated by using SEM. It was found that strain rate has little effect on engineering stress for the Mg-2.54Nd-0.26Zn-0.32Zr alloy when tested at below 250 A degrees C. When tested at above 250 A degrees C, low strain rate resulted in decreased engineering stress, increased elongation to fracture, and section shrinkage. The fracture mode is cleavage fracture with elongated dimple below 250 A degrees C and changes to typical ductile failure when tested above 250 A degrees C.