2026-04-22T20:22:53Zhttps://riubu.ubu.es/oai/request

oai:riubu.ubu.es:10259/55942024-07-25T07:18:53Zcom_10259_9476com_10259.4_106com_10259_2604col_10259_9477

Tallarita, Giovanna 81f40edb-9884-48b9-976a-0c940483e20d 500 Licheri, Roberta 2ce2400e-56e5-42b5-8aa6-a5a609a869c8 500 Garroni, Sebastiano 227 500 0000-0001-7686-6589 Barbarossa, Simone 9a4e3d00-5a66-4910-9ef7-2eb7a0cd72a7 500 Orrù, Roberto 46c89b08-835f-4508-9ae7-eda669401b81 500 Cao, Giacomo abae738d-e475-41ca-93b0-a096ee03427a 500 2021-01-13T11:25:12Z 2021-01-13T11:25:12Z 2020-04 0955-2219 http://hdl.handle.net/10259/5594 10.1016/j.jeurceramsoc.2019.10.031 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 application/pdf eng Elsevier 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 High-entropy ceramics Borides Spark plasma sintering Self-propagating high-temperature synthesis Resistance to oxidation Materiales Materials High-entropy transition metal diborides by reactive and non-reactive spark plasma sintering: A comparative investigation info:eu-repo/semantics/article info:eu-repo/semantics/acceptedVersion Journal of the European Ceramic Society 40 4 942 952 TEXT Tallarita-jecs_2020.pdf.txt Tallarita-jecs_2020.pdf.txt Extracted text text/plain 54173 https://riubu.ubu.es/bitstream/10259/5594/5/Tallarita-jecs_2020.pdf.txt d2286d20044cb46bf7c1f64fdb8c8479 MD5 5 THUMBNAIL Tallarita-jecs_2020.pdf.jpg Tallarita-jecs_2020.pdf.jpg IM Thumbnail image/jpeg 3753 https://riubu.ubu.es/bitstream/10259/5594/4/Tallarita-jecs_2020.pdf.jpg 91afaebfb8a7003609f9b41f26fd5c1e MD5 4 LICENSE license.txt license.txt text/plain; charset=utf-8 998 https://riubu.ubu.es/bitstream/10259/5594/3/license.txt aa90105e1c90a1b4fe810649aa967b7d MD5 3 CC-LICENSE license_rdf license_rdf application/rdf+xml; charset=utf-8 805 https://riubu.ubu.es/bitstream/10259/5594/2/license_rdf 4460e5956bc1d1639be9ae6146a50347 MD5 2 ORIGINAL Tallarita-jecs_2020.pdf Tallarita-jecs_2020.pdf application/pdf 2340219 https://riubu.ubu.es/bitstream/10259/5594/1/Tallarita-jecs_2020.pdf f27c6f712312abd98dd6c838aa488548 MD5 1 10259/5594 oai:riubu.ubu.es:10259/5594 2024-07-25 09:18:53.089 Repositorio Institucional de la Universidad de Burgos bubrep@ubu.es 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