Microstructure evolution in the hypo-eutectic alloy Al0.75CrFeNi2.1 manufactured by laser powder bed fusion and subsequent annealing
The hypo-eutectic medium entropy alloy Al0.75CrFeNi2.1 was processed by laser powder bed fusion (LPBF). The off-equilibrium solidification conditions prohibited coupled eutectic growth. Instead, the primary face centered cubic phase A1(FCC) solidified with a cellular morphology and the body centered...
| Autores: | , , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2023 |
| 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:2117/387348 |
| Acceso en línea: | https://hdl.handle.net/2117/387348 https://dx.doi.org/10.1016/j.msea.2022.144315 |
| Access Level: | acceso abierto |
| Palabra clave: | Titanium alloys Powder metallurgy Titani -- Aliatges Pulverimetal·lúrgia Àrees temàtiques de la UPC::Enginyeria dels materials |
| Sumario: | The hypo-eutectic medium entropy alloy Al0.75CrFeNi2.1 was processed by laser powder bed fusion (LPBF). The off-equilibrium solidification conditions prohibited coupled eutectic growth. Instead, the primary face centered cubic phase A1(FCC) solidified with a cellular morphology and the body centered, initially ordered B2(BCC) phase formed as a thin intercellular envelope. During post-build annealing an ultrafine quasi-lamellar pattern evolved following BCC growth and coarsening. The novel solid state transformation from cellular to lamellar morphology was attributed to a pronounced anisotropy of the FCC|BCC phase boundary energy. Microstructure evolution was also studied during continuous heating using in situ high-energy synchrotron X-ray diffraction (HEXRD) carried out at the beamline P07-HEMS of PETRA III (German Electron Synchrotron, DESY). The ultrafine and nano-scale features of the microstructure were quantitatively analyzed by atom probe tomography (APT) in the as-built condition and after isothermal annealing at 950 °C. The benefits of LPBF processing were discussed on the basis of mechanical properties measured by 3-point bending. The estimated tensile properties after annealing at 950 °C/6 h reached YS ˜ 860 MPa, UTS ˜1384 MPa with an elongation at fracture of ˜11%. Tensile properties in the as-built condition were comparable to martensitic steels. |
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