Strong grain neighbour effects in polycrystals
Anisotropy in single crystal properties of polycrystals controls both the overall response of the aggregates and patterning of local stress/strain distributions, the extremes of which govern failure processes. Improving the understanding of grain-grain interactions has important consequences for in-...
| Main Authors: | , , |
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| Format: | Journal article |
| Language: | English |
| Published: |
Springer Nature
2018
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| Summary: | Anisotropy in single crystal properties of polycrystals controls both the overall response of the aggregates and patterning of local stress/strain distributions, the extremes of which govern failure processes. Improving the understanding of grain-grain interactions has important consequences for in-service performance limits. Three-dimensional synchrotron X-ray diffraction was used to study the evolution of grain resolved stresses over many contiguous grains in Zr and Ti polycrystals deformed in situ. In a significant fraction of grains the stress along the loading axis was found to decrease during tensile plastic flow just beyond the macroscopic yield point; this is in the absence of deformation twinning and is a surprising behaviour. It is shown that this phenomenon is controlled by the crystallographic orientation of the grain and its immediate neighbours, particularly those adjacent along the loading axis. |
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