Deformation mechanisms of metastable stainless steels accessed locally by monotonic and cyclic nanoindentation

Metastable austenitic stainless steels feature an abundance of different deformation mechanisms, which contribute to the distinguished mechanical properties of these alloys. However, these properties are known to depend on the local microstructure and also are highly anisotropic. Furthermore, deform...

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Detalles Bibliográficos
Autor: Sapezanskaia, Ina
Tipo de recurso: tesis doctoral
Estado:Versión publicada
Fecha de publicación:2016
País:España
Institución:CBUC, CESCA
Repositorio:TDR. Tesis Doctorales en Red
OAI Identifier:oai:www.tdx.cat:10803/398401
Acceso en línea:http://hdl.handle.net/10803/398401
https://dx.doi.org/10.5821/dissertation-2117-98133
Access Level:acceso abierto
Palabra clave:Metastable austenitic stainless steels
Phase transformation
Cyclic nanoindentation
Plastic deformation mechanisms
Transmission electron microscopy (TEM)
Focused ion beam (FIB)
Scanning ion microscopy (SIM)
Crystalline anisotropy
Grain size
Plasticity transmission
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Descripción
Sumario:Metastable austenitic stainless steels feature an abundance of different deformation mechanisms, which contribute to the distinguished mechanical properties of these alloys. However, these properties are known to depend on the local microstructure and also are highly anisotropic. Furthermore, deformation is expected to be different for the bulk and the surface of a sample. In this sense, a discrete study is not trivial. The present work aims at investigation of the main deformation mechanisms and their gradual evolution, by employing controlled deformation of individual austenite grains via monotonic and cyclic nanoindentation. The corresponding loading–unloading curves have given extensive information about underlying mechanical properties, which could be related to an exhaustive reconstruction of the deformation substructure, both in surface and bulk, by different small scale characterization techniques. Amongst others, features such as time-dependent deformation, reversible phase transformation under load, crystalline anisotropy and grain size influences, besides plasticity transmission and fatigue behavior have been found and analyzed.