On the Precipitation Behavior at 250 and 300 °C of WE54 Supersaturated Solid Solution

Abstract

The current study seeks to further understand the precipitation sequence in a WE54 Mg alloy using in situ X-ray diffraction, micro-hardness and electrical resistivity during ageing at 250 and 300 °C. We show that the mean hardening effect is due to the precipitation of β' and β1metastable phases. The analysis of the kinetics of the precipitation shows that both phases nucleate at grain boundaries and within grains in the form of plates.

Effect of long-term natural aging on the microstructural characteristics of an extruded WE54 alloy

“…The main responsible mechanisms for the microstructural and textural modifications observed in Mg-RE alloys are principally related to the RE solute drag and Zener pinning of second phases which are effective obstacles for the grain boundary mobility and dislocation glide [2,4]. Accordingly, the influence of thermomechanical processing and artificial aging on the microstructure especially the precipitation behaviour and mechanical properties are widely investigated in Mg-RE alloys to control their design with better properties [8][9][10][11][12][13][14][15]. Nevertheless, only a few investigations can be found in the literature dealing with the impact of natural aging on the hardening behaviour of Mg-RE alloys [16][17][18][19][20][21].…”

“…For the first time, the present work presents the evolution of microstructure and texture of as-extruded WE54 (Mg-Y-Nd-Zr) alloy after long-term natural aging of 11 years using electron backscatter diffraction (EBSD) technique. In the past, the WE54 (Mg-4.9Y-4.2Nd-0.56Zr, wt.%) alloy was the subject of different investigations dealing with the effect of deformation processing and annealing treatments on the evolution of microstructure, texture, precipitation and mechanical properties [8][9][10][11][12].…”