Structure modulation driven by cyclic deformation in nanocrystalline NiFe

Journal Article · Fri Jan 01 04:00:00 EST 2010 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.104.255501· OSTI ID:982742

Cheng, Sheng ^[1]; Wang, Xun-Li ^[1]; Zhao, Yh ^[2]; Wang, Yinmin ^[3]; Liaw, Peter K ^[4]; Lavernia, Ej ^[2]

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1. ORNL
2. University of California, Davis
3. Lawrence Livermore National Laboratory (LLNL)
4. University of Tennessee, Knoxville (UTK)

Theoretical modeling suggests that the grain size remains unchanged during fatigue crack growth in nanocrystalline metals. Here we demonstrate that a modulated structure is generated in a nanocrystalline Ni-Fe alloy under cyclic deformation. Substantial grain coarsening and loss of growth twins are observed in the path of fatigue cracks, while the grains away from the cracks remain largely unaffected. Statistical analyses suggest that the grain coarsening is realized through the grain lattice rotation and coalescence and the loss of growth twins may be related to the detwinning process near crack tip.

• Research Organization: Oak Ridge National Laboratory (ORNL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 982742
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 255501 Vol. 104; ISSN 1079-7114; ISSN 0031-9007
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALLOYS
COALESCENCE
CRACK PROPAGATION
DEFORMATION
GRAIN SIZE
MODULATION
ROTATION
SIMULATION