ABSTRACT

In order to improve the corrosion resistance and bonding strength of the micro-arc oxidised (MAO) AZ91D magnesium (Mg) alloy, the hydroxyapatite (HA)-chitosan (CS) and polylactic acid hybrid (PLA) coatings on MAO Mg alloy were fabricated via electrochemical co-deposition and dip-coating method. The influences of different concentrations of PLA on the phase composition, surface morphology, hydrophobic, bonding strength, and corrosion resistance were investigated. The surface morphology and immersion test in simulated body fluid (SBF) showed that the PLA coating could further seal the surface and prevent the HA-CS coating from cracking, thus improving the corrosion resistance of the sample. The sample with 20% PLA had the lowest corrosion current density (1.13 × 10⁻⁸ A/cm²) and the highest strength (18.84 N). These results manifest that the MAO/HA-CS/PLA is a protective coating on magnesium alloys for implants application.

摘要

为了提高微弧氧化（MAO）AZ91D镁（Mg）合金的耐腐蚀性和结合强度，在MAO镁合金上制备了羟基磷灰石（HA）-壳聚糖（CS）和聚乳酸杂化（PLA）涂层。通过电化学共沉积和浸涂法。研究了不同浓度PLA对相组成、表面形貌、疏水性、结合强度和耐腐蚀性的影响。表面形貌和模拟体液（SBF）浸泡试验表明，PLA涂层可以进一步密封表面，防止HA-CS涂层开裂，从而提高样品的耐腐蚀性能。含有 20% PLA 的样品具有最低的腐蚀电流密度（1.13 × 10 ^-8 A/cm ²) 和最高强度 (18.84 N)。这些结果表明 MAO/HA-CS/PLA 是镁合金上用于植入物应用的保护涂层。