کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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5436153 | 1509544 | 2017 | 12 صفحه PDF | دانلود رایگان |
Deformation twinning contributes to a high work-hardening rate through modification of the dislocation structure and a dynamic Hall-Petch effect in polycrystalline steel. Due to the well-defined compression axis and limited deformation volume of micro-pillars, micro-compression testing is a suitable method to investigate the mechanisms of deformation twinning and the interactions of dislocations with twin boundaries. The material investigated is an austenitic Fe-22Â wt%Mn-0.6Â wt%C twining-induced plasticity steel. Micro-pillars oriented preferentially for deformation twinning and dislocation glide are compressed and the activated deformation systems are characterized. We observe that deformation twinning induces higher flow stresses and a more unstable work-hardening behavior than dislocation glide, while dislocation glide dominated deformation results in a stable work-hardening behavior. The higher flow stresses and unstable work-hardening behavior in micro-pillars oriented for deformation twinning are assumed to be caused by the activation of secondary slip systems and accumulated plastic deformation.
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Journal: Acta Materialia - Volume 132, 15 June 2017, Pages 162-173