Microstructure and mechanical properties of Mg–4.5Zn– xNd ( x = 0, 1 and 2, wt%) alloys

Abstract

Microstructure and mechanical properties of Mg–4.5Zn– xNd ( x = 0, 1 and 2, wt%) alloys heat-treated at 603 K for 2 h have been investigated. T-phase (an Mg–Zn–Nd ternary phase) was observed in the Nd containing alloys. The optimal mechanical properties were obtained in the Mg–4.5Zn–1Nd alloy, and the ultimate tensile strength and yield strength were 228 and 79 MPa, respectively. Through comparing with the Mg-4.5Zn alloy, the increments of ultimate tensile strength and yield strength were 51 and 17 MPa. However, the strength decreased with further addition of Nd, which was mainly due to the strong continuity of the interdendritic eutectics. The deformation behavior of the Nd containing alloys has also been investigated at 473 and 523 K, which indicated the occurrence of Portevin-Le Chatelier effect in the Mg–4.5Zn–2Nd alloy during tensile test at 523 K.