Deformation mechanisms of pure Zn studied by micropillar compression tests at room and elevated temperatures

The deformation mechanisms of pure Zinc (Zn) were studied through compression tests on single-crystal micropillars with various crystallographic orientations at both room temperature and 100 °C. When compressed along ∼ [ 1 ‾ 2 1 ‾ 1 ] , the grains mainly deformed by 〈 a 〉 basal slip. The second easiest mode in pure Zn is 〈 c + a 〉 pyramidal slip. No compression twinning or 〈 a 〉 non-basal slip was observed, implying these mechanisms require much higher critical resolved shear stresses than 〈 c + a 〉 pyramidal slip. Interestingly, 〈 c + a 〉 dislocations were found to transition from the pyramidal plane to the basal plane. This transition was sensitive to both temperature and orientation, leading to diverse microstructures under different conditions. For example, numerous sessile 〈 c + a 〉 dislocations were observed on the basal plane after compression along the c -axis at room temperature. These dislocations contribute to dislocation accumulation beneath the micropillar, ultimately triggering recrystallization at the bottom of the micropillar. These findings provide critical insights into the temperature- and orientation-dependent deformation mechanisms in Zn and offer valuable guidance for the design of Zn-based alloys with enhanced mechanical properties.