88382 20200716101500.0 doi 10.1016/j.jeurceramsoc.2019.04.015 sideral 111487 ART-2019-111487 eng (orcid)0000-0001-6337-5510 Moshtaghion, B.M. Universidad de Zaragoza Non-Hall-Petch hardness dependence in ultrafine fibrous MgAl 2 O 4 -MgO eutectic ceramics fabricated by the laser-heated floating zone (LFZ) method 2019 Access copy available to the general public Unrestricted MgAl 2 O 4 -MgO eutectic ceramics were fabricated by the laser-heated floating zone (LFZ) method with various growth rates to assess its possible beneficial effect on microstructural aspects and mechanical properties. It was determined that the growth rate optimizing the microstructure and mechanical properties is 750 mm/h; below this value, coarsening of the fibrous microstructure takes place with a degradation of these properties. In the extreme case of 50 mm/h growth rate, the presence of undesirable transverse cracks was unavoidable. Thanks to the high growth rate of 750 mm/h, ultra-fine fibrous microstructure MgAl 2 O 4 -MgO eutectic ceramics can thus be fabricated with greater hardness (15.5 GPa from Vickers indentation and 22 GPa from nanoindentation) and flexural strength (˜345 MPa). It is reported that hardness scales with the interfiber spacing ¿ according to a law of the type ln¿/¿, contrary to the assumed Hall-Petch-like dependence. This proposed law can be explained in terms of dislocation hardening induced by the MgO fibers. info:eu-repo/grantAgreement/ES/MINECO-FEDER/MAT2016-77769R info:eu-repo/grantAgreement/ES/MINECO/Juan de la Cierva Program info:eu-repo/semantics/openAccess by-nc-nd http://creativecommons.org/licenses/by-nc-nd/3.0/es/ 4.495 2019 MATERIALS SCIENCE, CERAMICS 1 / 28 = 0.036 2019 Q1 T1 1.164 2019 Materials Chemistry 2019 Q1 Ceramics and Composites 2019 Q1 info:eu-repo/semantics/article info:eu-repo/semantics/acceptedVersion (orcid)0000-0003-2242-6822 Peña, J.I. Universidad de Zaragoza 5001 065 Universidad de Zaragoza Dpto. Ciencia Tecnol.Mater.Fl. Área Cienc.Mater. Ingen.Metal. 39 (2019), 3208-3212 J. Eur. Ceram. Soc. Journal of the European Ceramic Society 0955-2219 532868 http://zaguan.unizar.es/record/88382/files/texto_completo.pdf Postprint 57396 http://zaguan.unizar.es/record/88382/files/texto_completo.jpg?subformat=icon icon Postprint oai:zaguan.unizar.es:88382 articulos driver 2020-07-16-09:12:45 ARTICLE