Energy principle of indentation contact: The application to sapphire

Roman Nowak, Mototsugu Sakai

Research output: Contribution to journalArticleScientificpeer-review

Abstract

The recently developed energy principle of indentation mechanics was applied to the continuous indentation test performed on pure sapphire. Three crystallographic planes, M = (1010BAR), A = (1210BAR), and C = (0001), have been indented by a symmetrical triangular pyramid (Berkovich). The distinct anisotropic behavior of the indented crystal has been observed for the maximum indentation loads of 1.961 N, 0.686 N, and 0.392 N. The indentation hysteresis loop energy and the related ''true hardness parameter'' have been determined for various crystallographic orientations, as well as for two different orientations of the indenter. The observed effects have been discussed in terms of the energy principle of indentation with crystallographic considerations. The effective resolved shear stresses for the slip and twinning systems were calculated and applied to the anisotropic indentation behavior. It was concluded that the energy principle is highly recommended for analyzing the data of continuous indentation tests.

Original languageEnglish
Pages (from-to)1068-1078
Number of pages11
JournalJournal of Materials Research
Volume8
Issue number5
DOIs
Publication statusPublished - 1993
MoE publication typeA1 Journal article-refereed

Keywords

  • HARDNESS TESTER
  • RESIDUAL-STRESS
  • ALUMINUM
  • NANOINDENTATION
  • PLASTICITY
  • MODULUS

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