Study of slip activity in a Mg-Y alloy by in situ high energy X-ray diffraction microscopy and elastic viscoplastic self-consistent modeling

Three-dimensional character of the deformation twin in magnesium

“…The easy slip associated with 〈 a 〉 dislocations on either the (0001) basal plane or the {} prismatic plane does not accommodate deformation along c -axis. On the other hand, 〈 c + a 〉 dislocations on nonbasal planes that can contribute to deformation along the c-axis are difficult to activate at room temperature due to high lattice friction 4–6 . As a consequence, twinning represents an alternative shear mechanism that accommodates plastic deformation along the c -axis 7–9 and so influences the ductility and formability of HCP metals 10–13 .…”

In Situ Electron Backscatter Diffraction Analysis for Microstructure Evolution and Deformation Models of Mg–Ce Alloy During Uniaxial Loading

“…Prismatic {10-10}<11-20> and pyramidal {10-11}<11-20> and also <c+a> slip {11-22}<-1-123> had been thought as an accommodation mechanism [21] for magnesium alloy at room and elevate temperatures, but the fraction of non-basal slip by total strain is quite low in most wrought alloy. Figure 4 shows the equivalent fraction of non-basal slip compared to basal slip in those observed grains A-K of Mg-Ce alloy, which suggests that Ce addition somehow changes the activation of deformation modes on the pyramidal planes in Mg. And recently, study on Mg-Y alloy also reported a high occurrence of <c+a> slip and increased activation of compression/secondary twins [7,15]. But the actual reason for this higher activation remains unclear.…”

“…The results suggested that the basal slip was activated in grains B, D and E and the dislocation slip the orientations of the normal direction of the grains according to the color key. And those grains and boundaries in which its CI value is lower than 0.3 in the data collection were shown as black on (10-11) plane was activated in grains C, G and H, and the dislocation slip on (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22) plane was activated in grains A, J and I. In grain K, no slip trace was observed and the deformation occurred on the grain boundaries supported by the voids on the grain boundaries between grain K and its neighbor grains.…”

“…While the critical resolved shear stress (CRSS) for <c+a> slip in magnesium is about 2.5 times higher than that for 1/3<11-20> basal slip [13], the <c+a> slip should be more difficult activated during deformation in pure Mg or AZ31 alloy at room temperature. Chino et al reported that the unique compression behavior of Mg-0.2%Ce was ascribed to non-basal slips [14], and more discussion had been focused on the solute drag effect with rare earth addition in Mg alloy and then its effect on the activation of non-basal dislocation slip [15]. However, the deformation models of Mg-Ce binary alloy are still unclear, and it is interesting to characterize the deformation models during deformation, and the results could help to understand the reason for the texture evolution and ductility improvement in Mg-Ce alloy.…”

Large elongations in WE54 magnesium alloy by solute-drag creep controlling the deformation behavior

“…Such alloy strengthening is caused by precipitation hardening and solid solution hardening [2,[6][7][8][9][10]. At the same time, these elements improve the ductility by weakening the recrystallization texture [11][12][13]. Additionally, it is worth to mention that the activation energies for the diffusion of these elements in the magnesium matrix are high and the diffusivity values are low and, therefore, the precipitation kinetics is strongly influenced by temperature [9].…”