Overcoming the trade-off between stretch formability and heat resistance in magnesium via alloying dilute neodymium

This work aims to provide a reliable reference and a low-cost strategy for overcoming the trade-off between stretch formability and heat resistance in Mg alloys. A dilute Mg-0.8 wt%Nd alloy sheet was prepared for this purpose, and hot compression was conducted in order to regulate the microstructure and texture. For comparison, the samples with and without hot compression were labeled as fine-grained (FG) and coarse -grained (CG) samples respectively, corresponding to the occurrence of dynamic recrystallization. Tensile creep tests were carried out at 473 K and Erichsen tests were conducted at room temperature. Both the CG and the FG samples had higher stretch formability and stronger creep resistance than commercial Mg alloys tested for comparison. Especially, the FG sample performed the best in overcoming the trade-off. Pyramidal < c+a > slip dominated the creep behavior of the FG sample and enhanced the heat resistance, avoiding the deterioration caused by cross-slip, twinning and grain boundary sliding. High Schmid factors for basal slip of the fine grains enhanced the stretch formability of the FG sample, and compensated the adverse effect of the relatively low Schmid factors of the residual coarse grains. Thus, the dilute Mg-0.8 wt% Nd alloy successfully overcame the trade-off between stretch formability and heat resistance. (c) 2021 Elsevier B.V. All rights reserved.