The effects of texture and grain morphology on the fracture toughness and fatigue crack growth resistance of nanocrystalline platinum films

Roi A. Meirom, Trevor E. Clark, Christopher L. Muhlstein

Research output: Contribution to journalArticle

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Abstract

The fracture toughness and fatigue crack growth resistance of nanocrystalline materials are significantly affected by the thickness of the specimen. In this work we relate the mechanical properties of nanocrystalline platinum films to their texture and grain morphology. Tensile, creep and fatigue testing of annealed, ∼1 μm films resulted in mechanical properties similar to the as-received films (yield strength of ∼1.2 GPa, fracture toughness ∼17.8 MPa √m, and a fatigue crack growth power law exponent of ∼4.2). However, the breakdown of the initially columnar grain morphology had a marked effect on the transition point from an intergranular to transgranular fatigue cracking mode. Finite element modeling suggests that cyclic (fatigue) grain coarsening and the transition from inter- to transgranular cracking modes are a result of the relative importance of dislocation slip accommodation on in-plane and through-thickness oriented slip directions.

Original languageEnglish (US)
Pages (from-to)258-269
Number of pages12
JournalInternational Journal of Fatigue
Volume70
DOIs
Publication statusPublished - Jan 2015

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All Science Journal Classification (ASJC) codes

  • Modeling and Simulation
  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering
  • Industrial and Manufacturing Engineering

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