Mechanical properties and in vitro bioactivity of silicon nitride ceramics with SiO2, CaO, and MgO additions

dc.creatorSONA FILHO, CELSO R.
dc.creatorCARVALHO, FLAVIO M. de S.
dc.creatorGUEDES-SILVA, CECILIA C.
dc.date2022
dc.date2022-01-27T17:55:37Z
dc.date2022-01-27T17:55:37Z
dc.date.accessioned2023-09-28T14:20:54Z
dc.date.available2023-09-28T14:20:54Z
dc.identifier1552-4973
dc.identifierhttp://repositorio.ipen.br/handle/123456789/32669
dc.identifier3
dc.identifier110
dc.identifier10.1002/jbm.b.34930
dc.identifier38.8
dc.identifier67
dc.identifier.urihttps://repositorioslatinoamericanos.uchile.cl/handle/2250/9002888
dc.descriptionSilicon nitride ceramics with SiO2, CaO, and MgO as sintering aids were investigated in view of biomedical applications. In the current study, samples with four different compositions were pressureless sintered at 1750??C for 1???h under a nitrogen atmosphere. The samples were evaluated concerning densification, microstructure, mechanical properties, and in vitro bioactivity. Microstructures with elongated ??-Si3N4 grains dispersed in an intergranular phase and with densities from 78.77 to 97.14% of the theoretical density were obtained. Higher contents of SiO2 resulted in the best densification and mechanical properties. Besides, replacements of CaO by MgO in the initial compositions affected Young's modulus and in vitro bioactivity. Considering the samples with relative density higher than 94.14%, those with lower values of Young's modulus had lower SiO2/MgO ratios. After immersion in SBF (Simulated Body Fluid), the samples with high porosity and/or partial replacements of CaO by MgO had their surfaces coated with a layer rich in calcium and phosphorus, morphologically similar to hydroxyapatite. Hence, producing silicon nitride ceramics with the potential to be used as orthopedic implants must consider ideal amounts of additives. In this article, the best combination of mechanical properties and mineralization capability was reached by the composition with low content of MgO, and high content of SiO2 and CaO.
dc.descriptionFunda????o de Amparo ?? Pesquisa do Estado de S??o Paulo (FAPESP)
dc.descriptionFAPESP: 15/02265-7
dc.format507-516
dc.relationJournal of Biomedical Materials Research Part B: Applied Biomaterials
dc.rightsopenAccess
dc.subjectceramics
dc.subjectmechanical properties
dc.subjectsilicon nitrides
dc.subjectsilicon oxides
dc.subjectcalcium oxides
dc.subjectmagnesium oxides
dc.titleMechanical properties and in vitro bioactivity of silicon nitride ceramics with SiO2, CaO, and MgO additions
dc.typeArtigo de peri??dico
dc.coverageI


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