Bimodal bulk nanocristalline (nc)/ultrafine (UF) aluminum was produced after cryomilling and spark plasma sintering consolidation process. The samples obtainedwere plastically deformed in uniaxial compression. We show that there is a significant fraction of plastic strain (11%) that can be recovered after unloading. High-energy synchrotron X-ray diffraction experiments revealed that, there is a correlation between plastic strain recovery and microstructural evolution detected during in-situ loading-unloading experiments. Using a deconvolution approach, the nanostructured volume fraction (grain size below 100 nm) and the UF counterpart (grain size above 100-150 nm)were separated in terms of lattice strain, microstrain, crystallite size and crystallographic texture. During loading-unloading cycles we observe a lattice strain splitting between nc and UF volume fractions, a complete recovery of the peak broadening and a recovery of texture.
These intriguing phenomena were explained to be strictly correlated with the lattice strain splitting behavior which act as the driving force for dislocation recombination.
| Identifer | oai:union.ndltd.org:unitn.it/oai:iris.unitn.it:11572/368281 |
| Date | January 2010 |
| Creators | Lonardelli, Ivan |
| Contributors | Lonardelli, Ivan, Molinari, Alberto |
| Publisher | Università degli studi di Trento, place:TRENTO |
| Source Sets | Università di Trento |
| Language | English |
| Detected Language | English |
| Type | info:eu-repo/semantics/doctoralThesis |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | firstpage:1, lastpage:116, numberofpages:116 |
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