The origin of superhardness in nanocomposite coatings: Analysis of nanoindentation and scratch tests

Chunsheng Lu, Yiu Wing Mai, Yao Gen Shen

Research output: Chapter in book / Conference proceedingConference article published in proceeding or bookAcademic researchpeer-review

Abstract

Nanocomposite coatings characterized by superhardness exhibit unique microstructures and deformation mechanisms at the nanometre scale. Based on the studies of nanoindentation size effect, we show that dislocation-based deformation is gradually replaced by grain-boundary mediated deformation as the hardness of coatings increases, especially for coatings approaching superhardness. The measured hardness of a superhard coating exponentially increases with the decrease of indentation depth, and its intrinsic hardness can be exactly determined by the analysis of indentation size effect. The optimal conditions extracted from acoustic emission signals from scratching superhard nanocomposite coatings are in good agreement with nanoindentation and drilling tests. In the optimal regime, it is the competition between different deformation mechanisms that results in the origin of superhardness in self-organized microstructures of nanocomposite coatings.

Original languageEnglish
Title of host publicationIUTAM Symposium on Mechanical Behavior and Micro-Mechanics of Nanostructured Materials - Proceedings of the IUTAM Symposium
PublisherSpringer Verlag
Pages39-49
Number of pages11
ISBN (Print)1402056230, 9781402056239
DOIs
Publication statusPublished - 2007
Externally publishedYes
EventIUTAM Symposium on Mechanical Behavior and Micro-Mechanics of Nanostructured Materials - Beijing, China
Duration: 27 Jun 200530 Jun 2005

Publication series

NameSolid Mechanics and its Applications
Volume144
ISSN (Print)1875-3507

Conference

ConferenceIUTAM Symposium on Mechanical Behavior and Micro-Mechanics of Nanostructured Materials
Country/TerritoryChina
CityBeijing
Period27/06/0530/06/05

Keywords

  • Acoustic emission
  • Nanoindentation
  • Size effect
  • Superhard coatings

ASJC Scopus subject areas

  • Civil and Structural Engineering
  • Automotive Engineering
  • Aerospace Engineering
  • Acoustics and Ultrasonics
  • Mechanical Engineering

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