High temperature nanoindentation of tungsten: Modelling and experimental validation

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Authors

Institutes & Expert groups

  • Central South University, School of Civil Engineering - Changsha 410075
  • Bruker Nano Surfaces Division, Bruker Nederland B.V. Elisabethhof 15, 2353, EW, Leiderdorp

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Abstract

Knowledge of mechanical properties of the tungsten surface region is extremely important for its application as first wall materials in plasma-facing components for nuclear fusion devices (e.g. ITER). Since tungsten is intrinsically brittle at room temperature, characterization of its ductile properties is possible only above the socalled ductile-to-brittle transition temperature (DBTT), which is above 500–700 K. This is why the development and qualification of instrumented hardness measurements at elevated temperature is an important task to enable the characterization of tungsten properties after exposure to heat shocks, plasma beam and ion irradiation, which all together mimic the actual operation conditions of nuclear fusion. We have performed nanoindentation measurements on tungsten in the constant stiffness mode using Bruker stage developed for high temperature operation with oxygen protective environment. Commercially pure tungsten of ITER specification is studied in the as-produced and as-recrystallized conditions to deduce the impact of the texture and forging on the hardness. The obtained results are analysed by means of crystal plasticity finite element method (CPFEM) model to subtract the constitutive laws for the elasto-plastic deformation and derive the strengthening term attributed to the contribution coming from statistically stored dislocations and grain boundaries.

Details

Original languageEnglish
Article number105222
Pages (from-to)1-12
Number of pages12
JournalInternational Journal of Refractory Metals & Hard Materials
Volume89
DOIs
Publication statusPublished - 22 Jun 2020

Keywords

  • High temperature, Nanoindentation, CPFEM, Tungsten, Dislocations, Hall-Petch

ID: 6784257