A dislocation-based crystal viscoplasticity model with application to micro-engineered plasma-facing materials

David Rivera, Yue Huang, Giacomo Po, Nasr M. Ghoniem

Research output: Contribution to journalArticlepeer-review

3 Scopus citations

Abstract

Materials developed with special surface architecture are shown here to be more resilient to the transient thermomechanical environments imposed by intermittent exposures to high heat flux thermal loading typical of long-pulse plasma transients. In an accompanying article, we present experimental results that show the relaxation of residual thermal stresses in micro-engineered W surfaces. A dislocation-based model is extended here within the framework of large deformation crystal plasticity. The model is applied to the deformation of single crystals, polycrystals, and micro-engineered surfaces composed of a uniform density of micro-pillars. The model is utilized to design tapered surface micro-pillar architecture, composed of a Re core and W coatings. Residual stresses generated by cyclic thermomechanical loading of these architectures show that the surface can be in a compressive stress state, following a short shakedown plasma exposure, thus mitigating surface fracture.

Original languageEnglish (US)
Pages (from-to)231-242
Number of pages12
JournalJournal of Nuclear Materials
Volume485
DOIs
StatePublished - Mar 1 2017
Externally publishedYes

Keywords

  • Plasma transients
  • Residual stress
  • Surface architecture
  • Thermomechanics
  • Tungsten

ASJC Scopus subject areas

  • Nuclear and High Energy Physics
  • Materials Science(all)
  • Nuclear Energy and Engineering

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