Effect of microstructural heterogeneity on the balanced-biaxial and tensile behavior of a Zn alloy sheet
A 0.65 mm thick Zn sheet was processed at room temperature by equal channel angular sheet extrusion (ECASE), which allowed for the fabrication of a heterogeneous material. The processed sheet's heterogeneity manifested as larger dislocation clusters and smaller grain sizes on the surface than i...
| Autores: | , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2022 |
| País: | España |
| Institución: | Universitat Politècnica de Catalunya (UPC) |
| Repositorio: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | inglés |
| OAI Identifier: | oai:upcommons.upc.edu:2117/375852 |
| Acceso en línea: | https://hdl.handle.net/2117/375852 https://dx.doi.org/10.1016/j.mtcomm.2022.103126 |
| Access Level: | acceso abierto |
| Palabra clave: | Dislocations in metals Heterogeneity Twinning Formability Dislocations Grain size Dislocacions en metalls Àrees temàtiques de la UPC::Enginyeria dels materials |
| Sumario: | A 0.65 mm thick Zn sheet was processed at room temperature by equal channel angular sheet extrusion (ECASE), which allowed for the fabrication of a heterogeneous material. The processed sheet's heterogeneity manifested as larger dislocation clusters and smaller grain sizes on the surface than in the sheet's center, generating as well a 35% increase in yield strength while preserving a fracture elongation of 26%. ECASE processing resulted in a slightly higher deformation limit than that of the as-received material with a weight reduction of 9%. The improvement in the processed sheet's mechanical properties was associated with the formation of twins on the surface, resulting in a smaller grain size and heterogeneity between the twins-free and twinned grains. These two microstructures produced a combination of hard and soft zones. ECASE processing formed twins in particular grains that in turn created a high density of geometrically necessary dislocation (GND) arrays in twin-free neighboring grains. It should be noted that the twinned grains had a low density of geometrically necessary dislocations (GND). In addition to the heterogeneity between twinned and twin free grains, a heterogeneous GND distribution was formed between the surface and the processed sheet's center, with the basal slip system dominating. |
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