2024-03-29T11:55:44Zhttps://riubu.ubu.es/oai/requestoai:riubu.ubu.es:10259/55942023-03-31T12:16:38Zcom_10259_4759com_10259_2604col_10259_4760
High-entropy transition metal diborides by reactive and non-reactive spark plasma sintering: A comparative investigation
Tallarita, Giovanna
Licheri, Roberta
Garroni, Sebastiano
Barbarossa, Simone
Orrù, Roberto
Cao, Giacomo
High-entropy ceramics
Borides
Spark plasma sintering
Self-propagating high-temperature synthesis
Resistance to oxidation
Materiales
Materials
The direct synthesis and consolidation by SPS (1950 °C, 20 min, 20 MPa) of high-entropy (Hf0.2Mo0.2Zr0.2Nb0.2Ti0.2)B2 from elemental powders resulted in a multiphase product. An increase of the heating rate determined a change of the mechanism governing the synthesis reaction from gradual solid-state diffusion to rapid combustion regime, while the final conversion degree was 67 wt.%. The sintered product displayed a non-uniform microstructure with the presence of 10–15 μm sized pores, due to volatilization phenomena occurring during the combustion synthesis reaction. In contrast, when the SPS process was preceded by powder synthesis via SHS, a homogeneous single-phase ceramic was obtained. Clear benefits are derived by the use of SHS, able to provide very shortly powders with elemental species very well intermixed, so that the obtainment of (Hf0.2Mo0.2Zr0.2Nb0.2Ti0.2)B2 during the subsequent SPS stage is strongly promoted. The resulting 92.5% dense product shows superior oxidation resistance with respect to individual borides prepared with the same method.
ARCHIMEDES project sponsored by Regione Autonoma della Sardegna (Italy) - Fondo di Sviluppo e Coesione (FSC) 2014-2020 (Cod. RAS: RASSR88309, Cod. CUP: F76C18000980002). One of the authors (G.T.) performed her activity in the framework of the International PhD in Innovation Sciences and Technologies at the University of Cagliari, Italy. One of us (G.C.) acknowledges the results obtained in this manuscript as quite important for the “Ithermal” and “Generazione E” projects, sponsored by Sardegna Ricerche, Italy (Cod. CUP: F21I18000130006) and by the Italian Ministry of Education, University and Research, Italy (Cod. CUP: B96G18000560005), respectively
2021-01-13T11:25:12Z
2021-01-13T11:25:12Z
2020-04
info:eu-repo/semantics/article
info:eu-repo/semantics/acceptedVersion
0955-2219
http://hdl.handle.net/10259/5594
10.1016/j.jeurceramsoc.2019.10.031
eng
Journal of the European Ceramic Society. 2020, V. 40, n. 4, p. 942-952
https://doi.org/10.1016/j.jeurceramsoc.2019.10.031
Attribution-NonCommercial-NoDerivatives 4.0 Internacional
http://creativecommons.org/licenses/by-nc-nd/4.0/
info:eu-repo/semantics/openAccess
application/pdf
Elsevier
https://riubu.ubu.es/bitstream/10259/5594/4/Tallarita-jecs_2020.pdf.jpg
Hispana
TEXT
http://creativecommons.org/licenses/by-nc-nd/4.0/
RIUBU. Repositorio Institucional de la Universidad de Burgos
http://hdl.handle.net/10259/5594