<p>Metallic materials with nanotwins
have been extensively studied for the past twenty years due to their excellent
mechanical properties including high strength, great ductility and good thermal
stability. Twin boundaries (TBs) can inhibit dislocation migration to increase
strength and renucleate new dislocations to accommodate plasticity. However,
the roles of stacking faults (SFs), another important planar defect, on the
deformation mechanisms in face-centered cubic (FCC) and hexagonal close-packed
(HCP) metals are less well understood. The focus of this research is to
identify the effect of SFs on deformation mechanisms in FCC and HCP Co thin
films and investigate the collaborated strengthening effect between SFs, TBs
and layer interfaces in Cu/Co multilayer systems. We utilized in situ
micropillar compression tests to investigate the mechanical behaviors of FCC Co
with inclined SFs, HCP Co with parallel SFs and Cu/Co multilayers with defect
networks, which consisting of SFs, TBs and layer interfaces. Post deformation
transmission electron microscopy analyses and molecular dynamic simulations
revealed that SFs can strengthen the materials by impeding partial dislocation
migration and accommodate plastic deformation by defaulting process and/or
intriguing phase transformation. Furthermore, the interplay between TBs, SFs
and layer interfaces provides high strength and good deformability in Cu/Co
nanolaminates. This research shows an in-depth investigation on deformation
mechanisms of nanostructured metals with high-density SFs and provides a new
perspective for the design of metallic materials with high strength and great
ductility.</p>
| Identifer | oai:union.ndltd.org:purdue.edu/oai:figshare.com:article/12578312 |
| Date | 10 September 2022 |
| Creators | Ruizhe Su (9036590) |
| Source Sets | Purdue University |
| Detected Language | English |
| Type | Text, Thesis |
| Rights | CC BY 4.0 |
| Relation | https://figshare.com/articles/thesis/Stacking_Faults_and_Interfaces_Dominated_Mechanical_Behaviors_of_Cobalt_and_Copper_Cobalt_Multilayers/12578312 |
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