Reversal in the Size Dependence of Grain Rotation
The conventional belief, based on the Read-Shockley model for the grain rotation mechanism, has been that smaller grains rotate more under stress due to the motion of grain boundary dislocations. However, in our high-pressure synchrotron Laue x-ray microdiffraction experiments, 70 nm nickel particles are found to rotate more than any other grain size. We infer that the reversal in the size dependence of the grain rotation arises from the crossover between the grain boundary dislocation-mediated and grain interior dislocation-mediated deformation mechanisms. The dislocation activities in the grain interiors are evidenced by the deformation texture of nickel nanocrystals. This new finding reshapes our view on the mechanism of grain rotation and helps us to better understand the plastic deformation of nanomaterials, particularly of the competing effects of grain boundary and grain interior dislocations.
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- Center for High Pressure Science and Technology Advanced Research, Shanghai (China); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Advanced Light Source
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Advanced Light Source
- Center for High Pressure Science and Technology Advanced Research, Shanghai (China)
- Univ.of California, Los Angeles, CA (United States). Dept. of Chemistry and Biochemistry
- Publication Date:
- Grant/Contract Number:
- AC02-05CH11231
- Type:
- Accepted Manuscript
- Journal Name:
- Physical Review Letters
- Additional Journal Information:
- Journal Volume: 118; Journal Issue: 9; Journal ID: ISSN 0031-9007
- Publisher:
- American Physical Society (APS)
- Research Org:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Org:
- USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 36 MATERIALS SCIENCE
- OSTI Identifier:
- 1379748
- Alternate Identifier(s):
- OSTI ID: 1345444
- Free Publicly Accessible Full Text
- Accepted Manuscript (Publisher)
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Accepted Manuscript (DOE)
- Publisher's Version of Record
- https://doi.org/10.1103/PhysRevLett.118.096101