Abstract:The high temperature deformation behavior of an extruded Mg-0.35Y-2.17Nd-0.36Zr (wt.%) alloy was investigated for biomedical application by employing compression tests in temperature range of 225-525 °C and strain rate range of 0.0003-0.03 s^-1. To study the significance of solute elements, the material was solution-treated before deformation. The low temperature yield strength of the as-extruded material significantly decreased after solutionizing process. A drastic change in the strength of solutionized alloy was recorded as the temperature was raised to 450 °C, which was attributed to the promotion of grain boundary sliding (GBS). It was evidently shown that the slip-to-twinning transition temperature did not necessarily coincide with the strength-drop temperature. Based on constitutive equations, deformation parameters and related activation energy for the experimental alloy have been determined, incorporating the strain-dependent material constants. The verification of predictability of the developed models indicates a good agreement between experimental and predicted data.

Key words: Mg alloy; hot deformation; constitutive model; twinning