Optimized method for the identification of slip directions in Mg alloy based on intragranular misorientation axes analysis

Abstract

In this work, an optimized method was proposed to identify the activated slip directions (i.e., gliding direction of dislocations) based on intragranular misorientation axes (IGMA) analysis only using electron backscattered diffraction (EBSD) data. By using MTEX toolbox in MATLAB software, the figures which showed the slip directions and the change of rotation angles (i.e, the grain reference orientation deviation (GROD) angles) in each grain, were plotted based on the EBSD data. By comparing the directions in which the GROD angle increases with the slip directions in the grain, the potential activated prismatic slip directions can be determined. Taking two grains in the extruded Mg–6Zn–1Y-0.5Zr alloy as examples. Two different prismatic slip directions belonging to two prismatic slip systems, [1-210] (GROD value: 0.64 → 0.75) and [-12-10] (GROD value: 0.34 → 0.74), were activated in the grain 1. Meanwhile, only one prismatic slip system, (10-10) [-12-10] (GROD value: 0.29 → 0.8), was initiated in the grain 2. Moreover, this method was further applied to determine the basal slip systems. Two basal slip systems, (0001) [-12-10] (GROD value: 2.7 → 4) and (0001) [-2110] (GROD value: 3.2 → 4.2), were activated in the selected grains, demonstrating that this method is also suitable for identifying the basal slip systems except for the prismatic systems. In summary, a novel method to determine the active slip directions in Mg alloys was successfully developed and experimentally validated in Mg alloys, which was simpler and more efficient compared to other widely utilized methods.

Keywords

• Mg alloy
• IGMA
• Slip
• Misorientation