Control of degradation rate of Mg alloys using silica sol–gel coatings for biodegradable implant materials

[EN] Silica sol–gel coatings were deposited on AZ31B and AZ91D magnesium substrates with the aim of controlling the degradation rate, corrosion attack and further dissolution of magnesium alloys for temporal implants. Two different silica sols were prepared with and without colloidal silica particle...

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Detalles Bibliográficos
Autores: Castro Martín, Yolanda, Durán, Alicia
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2018
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/266474
Acceso en línea:http://hdl.handle.net/10261/266474
Access Level:acceso abierto
Palabra clave:Sol–gel coatings
Mg alloys
Biodegradable
Descripción
Sumario:[EN] Silica sol–gel coatings were deposited on AZ31B and AZ91D magnesium substrates with the aim of controlling the degradation rate, corrosion attack and further dissolution of magnesium alloys for temporal implants. Two different silica sols were prepared with and without colloidal silica particles (MTL and TG sols) and deposited by dip-coating on both alloys. The coatings were characterised in SBF using three different in vitro tests; hydrogen evolution, pH variation and potentiodynamic polarization curves. The results show that the corrosion behaviour depends on the alloy and on the coating composition. Coatings on AZ91D-MTL were able to block the degradation of the alloy during 8 days of immersion in SBF, whereas coatings AZ91D-TG only maintain their stability during 3 days. Mg(OH) and hydroxyapatite (HAp) were identified as the compounds precipitated on AZ31B samples, not appearing on AZ91D samples. The electrochemical tests confirm the promising corrosion results obtained for coated AZ91D samples.