Evolution of a honeycomb network of precipitates in a hot-rolled commercial Mg–Y–Nd–Zr alloy

Abstract

Coupled processes of dynamic recovery and precipitation, occurring during hot-rolling and subsequent aging, lead to the formation of a unique honeycomb network of precipitates in commercial Mg-Y-Nd-Zr or WE43 alloy. The honeycomb network is developed on the (0 0 0 1) Mg basal planes and consisted of fine Nd-rich β 1 platelets lying on all three f1 0 1 0g Mg planes presumably decorating recovery-generated dislocation subcell boundaries. Three variants of β 1 platelets are connected by Y-rich b 0 precipitates at the nodes of the hexagonal honeycomb network.

Chemistry and morphology ofβ′ precipitates in an aged Mg-Nd-Y-Zr alloy

“…Concerning the single plate oriented parallel to the Mg f1 0 1 0g planes and exhibiting no solute ordering, its orientation is consistent with that of the β 1 phase. However, the measured stoichiometry is inconsistent with Mg 3 X stoichiometry previously reported for β 1 [13] and rather agrees with that of the β′ phase. Further detailed TEM investigations would clarify the nature of this precipitate.…”

“…have been measured using X-ray microanalysis and phase stoichiometries were reported as follows: Mg 3 Nd for the β″ phase, Mg 12 YNd for β′, Mg 3 (Nd,Y) for β 1 and Mg 14 Nd 2 Y for β [2][3][4][5][6]. However, previous atom probe tomography (APT) observations on a hot-rolled and aged WE43 alloy reported the presence of Zr as well as Nd and Y concentrations in the β′ precipitates at variance with the above-mentioned stoichiometries [13]. The significance of Zr within β′ precipitates was not discussed.…”

Friction stir additive manufacturing for high structural performance through microstructural control in an Mg based WE43 alloy

“…Currently, these vein like structures are speculated to be associated with b 1 precipitates due to the tendency of Nd to partition at dislocations [70,71]. The formation of these structures in the present study clearly indicates the presence of a higher fraction of low angle grain boundaries (LAGBs) at the interface after FSAM.…”

“…In this case, the matrix is populated with discontinuous fine needle/plate shaped precipitates [50 nm] and continuous vein like structures traversing the grain. In a recent study, Choudhuri et al [70] showed the presence of the vein like structures in the rolled condition and reasoned their existence due to preferential precipitation Table 5, (b) necklace structure along the grain boundaries after aging, (c) HAADF -STEM micrograph of the inset in (b) representative of the inhomogeneity in the rolled and aged condition.…”

Special Rolling Techniques for Improvement of Mechanical Properties of Ultrafine‐Grained Metal Sheets: a Review

“…[14] Rolling techniques have a long history dating back more than 100 years. Generally, the researchers have focused on product profile, [15][16][17][18][19] product defects, [20][21][22][23][24][25][26] product microstructure, [27][28][29][30] wear and lubrication of roll mill, [31][32][33][34] etc. With the rapid development of UFG/NG metals, severe plastic deformation techniques have become increasingly important in rolling.…”