Pezzato Luca, Brunelli Katya, Diodati Stefano, Pigato Mirko, Bonesso Massimiliano, Dabalà Manuele
Department of Industrial Engineering, University of Padua, Via Marzolo 9, 35131 Padova, Italy.
Department of Chemical Science, University of Padua, Via Marzolo 1, 35131 Padova, Italy.
Materials (Basel). 2021 Mar 21;14(6):1531. doi: 10.3390/ma14061531.
In this work, the composition of an electrolyte was selected and optimized to induce the formation of hydroxyapatite during Plasma electrolytic oxidation (PEO) treatment on an AZ31 alloy for application in bioabsorbable implants. In detail, the PEO process, called PEO-BIO (Plasma Electrolytic Oxidation-Biocompatible), was performed using a silicate-phosphate-based electrolyte with the addition of calcium oxide in direct-current mode using high current densities and short treatment times. For comparison, a known PEO process for producing anticorrosive coatings, called standard, was applied on the same alloy. The coatings were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and XPS analyses. The corrosion performance was evaluated in simulated body fluid (SBF) at 37 °C. The coating produced on the PEO-BIO sample was porous and thicker than the standard PEO one, with zones enriched in Ca and P. The XRD analysis showed the formation of hydroxyapatite and calcium oxides in addition to magnesium-silicon oxide and magnesium oxide in the PEO-BIO sample. The corrosion resistance of PEO-BIO sample was comparable with that of a traditional PEO treated sample, and higher than that of the untreated alloy.
在本研究中，选择并优化了一种电解质的成分，以在AZ31合金的等离子体电解氧化（PEO）处理过程中诱导羟基磷灰石的形成，用于生物可吸收植入物。具体而言，采用基于硅酸盐-磷酸盐的电解质，并添加氧化钙，以高电流密度和短处理时间在直流模式下进行名为PEO-BIO（等离子体电解氧化-生物相容性）的PEO工艺。为作比较，在同一合金上应用了一种已知的用于生产防腐涂层的PEO工艺，称为标准工艺。通过扫描电子显微镜（SEM）、X射线衍射（XRD）和XPS分析对涂层进行表征。在37°C的模拟体液（SBF）中评估其耐腐蚀性能。PEO-BIO样品上产生的涂层比标准PEO涂层更厚且多孔，富含Ca和P区域。XRD分析表明，PEO-BIO样品中除了形成羟基磷灰石和氧化钙外，还有镁-硅氧化物和氧化镁。PEO-BIO样品的耐腐蚀性与传统PEO处理样品相当，且高于未处理合金。
