101612 20220405150420.0 doi 10.1016/j.jeurceramsoc.2020.05.015 sideral 117944 ART-2020-117944 eng Moshtaghioun, B.M. Universidad de Zaragoza (orcid)0000-0001-6337-5510 Mg2SiO4-MgAl2O4 directionally solidified eutectics: Hardness dependence modelled through an array of screw dislocations 2020 Access copy available to the general public Unrestricted Mg2SiO4-MgAl2O4 eutectic ceramics have been fabricated by means of the laser floating zone (LFZ) technique. The microstructure has revealed as an unusual one at lower growth rate, composed of broken lamellae of MgAl2O4 distributed randomly along one matrix, composed of Mg2SiO4. At higher growth rates, a cell structure with intra-cell lamella structure is dominant. Contrary to most eutectic systems, hardness is not dependent upon the inter-spacing, but it does depend on one characteristic length of lamellae: their perimeter. One simple model based upon the dislocation is proposed, which successfully accounts for such extraordinary hardness law. Accordingly, Mg2SiO4-MgAl2O4 eutectic ceramics fabricated at 50 mm/h growth rate with the smallest MgAl2O4 lamella perimeter favorably showed more elevated hardness (13.4 GPa from Vickers indentation and 15.3 GPa from nanoindentation) and strength (~430 MPa) than those found in the monolithic Mg2SiO4 matrix. info:eu-repo/grantAgreement/ES/DGA-FEDER/T02-17R info:eu-repo/grantAgreement/ES/MINECO-FEDER/MAT2015-71411-R 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/ 5.302 2020 MATERIALS SCIENCE, CERAMICS 2 / 29 = 0.069 2020 Q1 T1 1.204 2020 Materials Chemistry 2020 Q1 Ceramics and Composites 2020 Q1 info:eu-repo/semantics/article info:eu-repo/semantics/acceptedVersion Gomez-Garcia, D. Peña, J.I. Universidad de Zaragoza (orcid)0000-0003-2242-6822 5001 065 Universidad de Zaragoza Dpto. Ciencia Tecnol.Mater.Fl. Área Cienc.Mater. Ingen.Metal. 40, 12 (2020), 4171-4176 J. Eur. Ceram. Soc. Journal of the European Ceramic Society 0955-2219 783852 http://zaguan.unizar.es/record/101612/files/texto_completo.pdf Postprint 2642614 http://zaguan.unizar.es/record/101612/files/texto_completo.jpg?subformat=icon icon Postprint oai:zaguan.unizar.es:101612 articulos driver 2022-04-05-14:39:17 ARTICLE