کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1578879 | 1001216 | 2011 | 8 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Interpreting strain bursts and size effects in micropillars using gradient plasticity Interpreting strain bursts and size effects in micropillars using gradient plasticity](/preview/png/1578879.png)
Size effects and strain bursts that are observed in compression experiments of single crystalline micropillars are interpreted using a gradient plasticity model that can capture the process of sequential slip and heterogeneous yielding of thin material layers. According to in situ experiments during compression sub-grains and significant strain gradients develop, while deformation occurs through slip layers in the gauge region. In the multilayer strain gradient model, the higher order stress is discontinuous across the interface between a plastic layer and an elastic layer, but it becomes continuous across the interface between two plastic layers. Strain bursts occur when two neighboring layers yield. Based on this hypothesis the experimental stress–strain curves with strain bursts observed in micropillars can be fitted by properly selecting the number of layers that yield and the ratio of the internal length over the specimen size; the modulus and the yield stress are obtained from the experimental curves while the hardening modulus evolves during deformation based on the dislocation mechanisms.
Research highlights
► Capture strain bursts in stress–strain curves of compressed micropillars.
► Capture the size effects in the stress–strain response of compressed micropillars.
► Perfect fit of theoretical model to experimental stress–strain curves obtained in D.M. Dimiduk, M.D. Uchic, T.A. Parthasarathy, Acta Mater. 53 (2005) 4065–4077.
Journal: Materials Science and Engineering: A - Volume 528, Issue 15, 15 June 2011, Pages 5036–5043