Fig. 1. (a) Schematic diagrams showing slip propagation from one grain to the neighboring grain and transmission electron microscopy (TEM) image showing dislocation transfer behavior, (b) schematic diagrams showing twinning propagation from one grain to the neighboring grain and inverse pole figure map showing the {101ˉ2} twin (T) transfer and formation of twin pairs (T1-T2) in a 0.5% compressed Mg plate (adapted from Yu et al. [26] and Shen et al. [16]).

Fig. 2. (a) Flow stress as a function of the inverse square root of grain size with (grey points) or without internal stress (black points) and the inverse pole figures obtained by EBSD for three domains [64], and (b) Hall-Petch relationship and X-ray pole figures for extruded and FSPed specimens at room temperature [34].

Fig. 3. Activation stresses for dominant deformation modes as a function of the tilting angle of basal poles (φ) with respect to the loading direction (LD) under (a) tension [26] and (b) compression in the Mg alloys. Note that the CRSS ratio of 1: 1: 2: 5 for basal slip (10 MPa):{101ˉ2} twinning (10 MPa): prismatic slip (20 MPa): {101ˉ1} twinning (50 MPa) is chosen.

Fig. 4. Inverse pole figure maps showing the grains favoring basal slip in an Mg alloy AZ31 plate under tension along TD. The grains labeled with B and P denote that the grains favor basal slip and prismatic slip, respectively [26].

Fig. 5. Maximum geometrical compatibility factor as a function of the tilting angle (θ) of c-axes between two neighboring grains and the rotation angle (ω) around the c-axis: (a) twinning-twinning transfer (m’T-T); (b) prismatic-prismatic slip transfer (m’P-P); (c) basal-basal slip transfer (m’B-B); (d) basal-prismatic slip transfer (m’B-P) [26].

Fig. 6. Variation of yield stress against grain size-1/2 for prismatic slip in Mg alloys [39]. ky is Hall-Petch slope.

Fig. 7. Energy barriers for slip to penetrate a grain boundary (GB) plotted against the static GB energy for various types of coincidence site lattice (CSL) GBs [124].

Fig. 8. Hall-Petch slope as a function of plastic strain [21].