Ascertaining the plastic deformation mechanisms of polycrystalline extruded Zn through in situ SEM/EBSD mechanical tests

作者：A. Rezaei, Nafiseh Mollaei, Maral Sarebanzadeh, Biaobiao Yang, Seyed Mahmood Fatemi, Javier LLorca · 发表于：International Journal of Plasticity · 年份：2025 · DOI：10.1016/j.ijplas.2025.104548 · 被引用次数：10 · 研究领域：Microstructure and mechanical properties、Electronic Packaging and Soldering Technologies、Nanomaterials and Printing Technologies

• The sequence of plastic deformation mechanisms of polycrystalline Zn was reported by means of in situ mechanical tests in the SEM. • Plastic deformation was initially accommodated by basal slip, leading to hardening, and grain boundary sliding. • Slip transfer at grain boundaries was never found because of grain boundary sliding. • <c+a> pyramidal II slip was also found but <c+a> pyramidal dislocations were dissociated into the basal plane and became sessile. • The contribution of twinning to the total strain was limited (around 11% when the applied strain was 16.7%). • •The strain hardening rate decreased sharply beyond 6.7% because of grain boundary slding and compression twinning The plastic deformation micro-mechanisms of extruded pure Zn deformed in tension along the extrusion direction were investigated by means of in situ scanning electron microscopy (SEM) integrated with electron back-scatter diffraction (EBSD). Plastic deformation began with the activation of < a > basal slip in grains with the highest Schmid factor while the incompatibility of deformation between neighbour grains was accommodated by grain boundary sliding. The geometrically necessary dislocation density increased sharply from 1.53 × 10 13 m⁻² to 9.03 × 10 13 m⁻² when applied strain reached 6.7%, and this increase coincides with the strong initial strain hardening region. The incompatibility of deformation between neighbour grains was accommodated by grain boundary sliding at strains above 3.3%, ...