On the underlying micromechanisms in time-dependent anelasticity in Al-(1 wt%)Cu thin films
| Autor: | Jpm Johan Hoefnagels, Mgd Marc Geers, Lijc Lambert Bergers |
|---|---|
| Přispěvatelé: | Mechanics of Materials, Group Geers, Group Hoefnagels |
| Rok vydání: | 2017 |
| Předmět: |
Al-Cu alloy
Materials science Polymers and Plastics Thin films 02 engineering and technology Bending 01 natural sciences 0103 physical sciences Composite material 010302 applied physics Precipitation (chemistry) Metallurgy Metals and Alloys Microbeam Creep 021001 nanoscience & nanotechnology Electronic Optical and Magnetic Materials Deformation mechanism Ceramics and Composites Grain boundary Dislocation 0210 nano-technology Anelasticity Micromechanical testing Electron backscatter diffraction |
| Zdroj: | Acta Materialia, 124, 47-58. Elsevier |
| ISSN: | 1359-6454 |
| DOI: | 10.1016/j.actamat.2016.10.058 |
| Popis: | This paper reveals potential micro mechanisms underlying time-dependent anelasticity observed in Al-(1 wt%)Cu thin films. The analyzed deformation mechanisms involve dislocation motion and interaction with solute diffusion, grain boundaries and precipitates. In order to investigate the role of these mechanisms, Al-(1 wt%)Cu alloy thin films are heat treated to systematically change the precipitation state, while characterizing the grain boundary distribution with electron backscatter diffraction. Micromechanical characterization is performed by microbeam bending, nano-tensile creep testing and nano-indentation. Results in microbeam bending reveal, for all precipitate and grain boundary states considered, a similar time-dependent evolution of the anelastic strain after load release. The magnitude of the recovered strain is also observed to be independent of the precipitate or grain boundary configuration. The nano-tensile creep test also indicates the same time-dependent anelastic evolution, indicating that the loading state does not affect the underlying mechanisms. Analysis of strain bursts in nano-indentation shows that pinning of dislocations by Cu solutes is unaffected by the precipitation state. Based on uniaxial creep and time-dependent anelasticity measurements in pure Al specimens, it is made plausible that the time-dependent anelasticity originates from diffusion-limited glide or climb of dislocation segments that are pinned at Cu solutes or in dislocation structures, which provide an internal driving force. |
| Databáze: | OpenAIRE |
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