A new criterion for elasto-plastic transition in nanomaterials: Application to size and composite effects on Cu–Nb nanocomposite wires
✍ Scribed by Ludovic Thilly; Steven Van Petegem; Pierre-Olivier Renault; Florence Lecouturier; Vanessa Vidal; Bernd Schmitt; Helena Van Swygenhoven
- Book ID
- 103998825
- Publisher
- Elsevier Science
- Year
- 2009
- Tongue
- English
- Weight
- 937 KB
- Volume
- 57
- Category
- Article
- ISSN
- 1359-6454
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✦ Synopsis
Nanocomposite wires composed of a multi-scale Cu matrix embedding Nb nanotubes are cyclically deformed in tension under synchrotron radiation in order to follow the X-ray peak profiles (position and width) during mechanical testing. The evolution of elastic strains vs. applied stress suggests the presence of phase-specific elasto-plastic regimes. The nature of the elasto-plastic transition is uncovered by the ''tangent modulus" analysis and correlated to the microstructure of the Cu channels and the Nb nanotubes. Finally, a new criterion for the determination of the macroyield stress is given as the stress to which the macroscopic work hardening, h a = dr a /de 0 , becomes smaller than one third of the macroscopic elastic modulus.