Application of a modified slip-distance theory to the indentation of single-crystal and polycrystalline copper to model the interactions between indentation size and structure size effects

X. Hou, N.M. Jennett

Research output: Contribution to journalArticle

27 Citations (Scopus)

Abstract

Plasticity size effects offer both measurement challenges and opportunities for material engineering. We have used nano-indentation to study the relationship between different size effects. Hardness varies significantly with indent size in single crystals, and also in polycrystals, whenever indent sizes and structure sizes are within an order of magnitude of each other. We exploit the geometric self-similarity of a Berkovich indenter and apply slip distance theory to indents of different sizes at a constant indentation strain. We show that indent size, grain size and pinning defects combine in a single, length-scale-dependent deformation mechanism, to determine the yield strength (hardness) of a material. This provides an excellent foundation for: improved grain size determination by indentation, design rules for combining different methods of yield stress enhancement and using indentation to probe local stress–strain properties of a material, or for mapping residual stress.
Original languageEnglish
Pages (from-to)4128-4135
Number of pages8
JournalActa Materialia
Volume60
Issue number10
DOIs
Publication statusPublished - 2012

Fingerprint

Indentation
Copper
Single crystals
Yield stress
Hardness
Size determination
Polycrystals
Nanoindentation
Plasticity
Residual stresses
Defects

Keywords

  • Size effects
  • Nanoindentation
  • Grain size
  • Crystal plasticity
  • Dislocation density

Cite this

@article{9bc26f594cec4255a97308ff9346d137,
title = "Application of a modified slip-distance theory to the indentation of single-crystal and polycrystalline copper to model the interactions between indentation size and structure size effects",
abstract = "Plasticity size effects offer both measurement challenges and opportunities for material engineering. We have used nano-indentation to study the relationship between different size effects. Hardness varies significantly with indent size in single crystals, and also in polycrystals, whenever indent sizes and structure sizes are within an order of magnitude of each other. We exploit the geometric self-similarity of a Berkovich indenter and apply slip distance theory to indents of different sizes at a constant indentation strain. We show that indent size, grain size and pinning defects combine in a single, length-scale-dependent deformation mechanism, to determine the yield strength (hardness) of a material. This provides an excellent foundation for: improved grain size determination by indentation, design rules for combining different methods of yield stress enhancement and using indentation to probe local stress–strain properties of a material, or for mapping residual stress.",
keywords = "Size effects, Nanoindentation, Grain size, Crystal plasticity, Dislocation density",
author = "X. Hou and N.M. Jennett",
year = "2012",
doi = "10.1016/j.actamat.2012.03.054",
language = "English",
volume = "60",
pages = "4128--4135",
journal = "Acta Materialia",
issn = "1359-6454",
publisher = "Elsevier",
number = "10",

}

TY - JOUR

T1 - Application of a modified slip-distance theory to the indentation of single-crystal and polycrystalline copper to model the interactions between indentation size and structure size effects

AU - Hou, X.

AU - Jennett, N.M.

PY - 2012

Y1 - 2012

N2 - Plasticity size effects offer both measurement challenges and opportunities for material engineering. We have used nano-indentation to study the relationship between different size effects. Hardness varies significantly with indent size in single crystals, and also in polycrystals, whenever indent sizes and structure sizes are within an order of magnitude of each other. We exploit the geometric self-similarity of a Berkovich indenter and apply slip distance theory to indents of different sizes at a constant indentation strain. We show that indent size, grain size and pinning defects combine in a single, length-scale-dependent deformation mechanism, to determine the yield strength (hardness) of a material. This provides an excellent foundation for: improved grain size determination by indentation, design rules for combining different methods of yield stress enhancement and using indentation to probe local stress–strain properties of a material, or for mapping residual stress.

AB - Plasticity size effects offer both measurement challenges and opportunities for material engineering. We have used nano-indentation to study the relationship between different size effects. Hardness varies significantly with indent size in single crystals, and also in polycrystals, whenever indent sizes and structure sizes are within an order of magnitude of each other. We exploit the geometric self-similarity of a Berkovich indenter and apply slip distance theory to indents of different sizes at a constant indentation strain. We show that indent size, grain size and pinning defects combine in a single, length-scale-dependent deformation mechanism, to determine the yield strength (hardness) of a material. This provides an excellent foundation for: improved grain size determination by indentation, design rules for combining different methods of yield stress enhancement and using indentation to probe local stress–strain properties of a material, or for mapping residual stress.

KW - Size effects

KW - Nanoindentation

KW - Grain size

KW - Crystal plasticity

KW - Dislocation density

U2 - 10.1016/j.actamat.2012.03.054

DO - 10.1016/j.actamat.2012.03.054

M3 - Article

VL - 60

SP - 4128

EP - 4135

JO - Acta Materialia

JF - Acta Materialia

SN - 1359-6454

IS - 10

ER -