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Title: Thermomechanics of Nanocrystalline Nickel Under High Pressure-Temperature Conditions

Abstract

We present a comparative study of thermomechanical properties of nano-polycrystalline nickel (nano-Ni) and micrometer-polycrystalline nickel (micron-Ni) by in situ high pressure-temperature (P-T) diffraction experiments. The yield strength of 2.35 GPa for the nano-Ni measured under high-pressure triaxial compression is more than three times that of the micron-Ni value. Contrary to tensile experiments of uniaxial loading, we observe significant work-hardening for the nano-Ni in high-pressure plastic deformation stage, whereas the micron-Ni experiences minor high-pressure work-softening and considerable energy dissipation into heat. The significantly reduced energy dissipation for the nano-Ni during the loading-unloading cycle indicates that the nanostructured materials can endure much greater mechanical fatigue in cyclic loadings. The nano-Ni exhibits steady grain growth during bulk plastic deformation at high-pressure loading, and drastic stress reduction and grain growth occur during the high P-T cycle. Our experiments utilized novel approaches to comparatively study micro- and nanostructured materials revealing recoverability of elastic/plastic deformations, strain corrections by diffraction elasticity ratio, and identifying dominances of stress relaxation, grain growth, and intrinsic residual stresses. The results should be of considerable interest to the fields of materials science, condensed matter, and computational physics.

Authors:
; ; ; ; ;
Publication Date:
Research Org.:
Brookhaven National Laboratory (BNL) National Synchrotron Light Source
Sponsoring Org.:
Doe - Office Of Science
OSTI Identifier:
930321
Report Number(s):
BNL-81031-2008-JA
TRN: US200822%%1469
DOE Contract Number:
DE-AC02-98CH10886
Resource Type:
Journal Article
Resource Relation:
Journal Name: Nano Letters; Journal Volume: 7; Journal Issue: 2
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; COMPRESSION; CORRECTIONS; DEFORMATION; DIFFRACTION; ELASTICITY; ENERGY LOSSES; FATIGUE; GRAIN GROWTH; HEAT; LOADING; MATERIALS; MATTER; NICKEL; PHYSICS; PLASTICS; PRESSURE RANGE MEGA PA 10-100; REDUCTION; RESIDUAL STRESSES; STRAIN HARDENING; STRAIN SOFTENING; STRAINS; STRESS RELAXATION; YIELD STRENGTH; national synchrotron light source

Citation Formats

Zhao,Y., Zhang, J., Clausen, B., Shen, T., Gray, G., and Wang, L.. Thermomechanics of Nanocrystalline Nickel Under High Pressure-Temperature Conditions. United States: N. p., 2007. Web. doi:10.1021/nl062685s.
Zhao,Y., Zhang, J., Clausen, B., Shen, T., Gray, G., & Wang, L.. Thermomechanics of Nanocrystalline Nickel Under High Pressure-Temperature Conditions. United States. doi:10.1021/nl062685s.
Zhao,Y., Zhang, J., Clausen, B., Shen, T., Gray, G., and Wang, L.. Mon . "Thermomechanics of Nanocrystalline Nickel Under High Pressure-Temperature Conditions". United States. doi:10.1021/nl062685s.
@article{osti_930321,
title = {Thermomechanics of Nanocrystalline Nickel Under High Pressure-Temperature Conditions},
author = {Zhao,Y. and Zhang, J. and Clausen, B. and Shen, T. and Gray, G. and Wang, L.},
abstractNote = {We present a comparative study of thermomechanical properties of nano-polycrystalline nickel (nano-Ni) and micrometer-polycrystalline nickel (micron-Ni) by in situ high pressure-temperature (P-T) diffraction experiments. The yield strength of 2.35 GPa for the nano-Ni measured under high-pressure triaxial compression is more than three times that of the micron-Ni value. Contrary to tensile experiments of uniaxial loading, we observe significant work-hardening for the nano-Ni in high-pressure plastic deformation stage, whereas the micron-Ni experiences minor high-pressure work-softening and considerable energy dissipation into heat. The significantly reduced energy dissipation for the nano-Ni during the loading-unloading cycle indicates that the nanostructured materials can endure much greater mechanical fatigue in cyclic loadings. The nano-Ni exhibits steady grain growth during bulk plastic deformation at high-pressure loading, and drastic stress reduction and grain growth occur during the high P-T cycle. Our experiments utilized novel approaches to comparatively study micro- and nanostructured materials revealing recoverability of elastic/plastic deformations, strain corrections by diffraction elasticity ratio, and identifying dominances of stress relaxation, grain growth, and intrinsic residual stresses. The results should be of considerable interest to the fields of materials science, condensed matter, and computational physics.},
doi = {10.1021/nl062685s},
journal = {Nano Letters},
number = 2,
volume = 7,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}
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