Guerra-Mutis, Marlon HernandoVega Vega, Jesus ManuelBarrena Pérez, María IsabelMatykina, EndzheArrabal Durán, Raúl2025-04-012025-04-012025-01-1310.1016/j.jma.2025.01.007https://hdl.handle.net/20.500.14352/119115Forman parte del fichero: 32 archivos Excel con datos de las figuras correspondientes 2 archivos powerpoint con imágenes del manuscrito y suplementarias 2 archivos word con tablas del manuscrito y suplementarias 4 archivos de video en formato MP4In this study, a phosphate-based conversion coating (PCC) was applied as a precursor before forming silicate-fluoride (SiF) and silicate-phosphate-fluoride (SiPF) based flash-plasma electrolytic oxidation (Flash-PEO) coatings on AZ31B magnesium alloy. The main novelty is the successful incorporation of calcium, zinc, manganese and phosphate species into the Flash-PEO coatings via a precursor layer rather than using the electrolyte. The precursor also led to longer lasting and more intense discharges during the PEO process, resulting in increased pore size. Corrosion studies revealed similar short-term performance for all coatings, with impedance modulus at low frequencies above 107 Ωcm2, and slightly better performance for the SiPF-based coating. Nonetheless, the enlarged pores in the PEO coatings functionalized with the PCC precursor compromised the effectiveness of self-healing mechanisms by creating diffusion pathways for corrosive species, leading to earlier failure. These phenomena were effectively monitored by recording the open circuit potential during immersion in 0.5 wt.% NaCl solution. In summary, this study demonstrates that conversion coatings are a viable option for the functionalization of PEO coatings on magnesium alloys, as they allow for the incorporation of cationic and other species. However, it is crucial to maintain a small pore size to facilitate effective blockage through self-healing mechanisms.engAttribution-NonCommercial-ShareAlike 4.0 Internationalhttp://creativecommons.org/licenses/by-nc-sa/4.0/datasethttps://doi.org/10.1016/j.jma.2025.01.007https://hdl.handle.net/20.500.14352/119023open access620AZ31 magnesium alloyPhosphatesChemical conversion coatingFlash plasma electrolytic oxidationElectrochemical Impedance SpectroscopyTransmission electron microscopyMateriales3312 Tecnología de Materiales