Multi-temperature indentation creep tests on nanotwinned copper

Xusheng Yang, Hui Ru Zhai, Haihui Ruan, San Qiang Shi, Tong Yi Zhang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

5 Citations (Scopus)

Abstract

The present work further develops the multi-temperature approach on load, time, and temperature-dependent deformation for indentation creep. Multi-temperature micro-indentation creep tests were carried out on nanotwinned copper (nt-Cu) at five temperatures of 22 °C (RT), 40 °C, 50 °C, 60 °C and 70 °C. In analogy with stress, hardness is used to gauge the indentation creep loading level, while the indentation depth is used to characterize the indentation creep deformation and the creep strain rate is represented by the indentation depth strain rate. The multi-temperature micro-indentation creep tests generate sufficiently large experimental data, which makes the development of a novel formula for indentation creep feasible. There are few intrinsic parameters that characterize the capability of the microstructure of a material against load, time, and temperature dependent deformation and they are the strain rate sensitivity, the athermal hardness exponent, intrinsic activation energy, and activation volume. The strain rate sensitivity is determined from isothermal creep data at one temperature, while the other parameters have to be determined from multi-temperature creep data. The novel formula is validated by the experimental data of the multi-temperature indentation creep tests on the nt-Cu. The creep mechanisms of the nt-Cu are also discussed and analyzed by using the determined values of the intrinsic parameters.
Original languageEnglish
Pages (from-to)68-79
Number of pages12
JournalInternational Journal of Plasticity
Volume104
DOIs
Publication statusPublished - 1 May 2018

Keywords

  • Creep activation parameters
  • Hardness
  • Indentation creep
  • Nanotwin
  • Twin boundary migration

ASJC Scopus subject areas

  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering

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