医用镁合金ZrO2陶瓷膜制备及其骨生物活性研究

摘要:

为了提高医用镁合金的耐蚀性及骨生物活性，分别在锆盐体系和硅酸盐体系溶液中，采用微弧氧化技术在镁合金表面制备具有生物活性的陶瓷膜。利用X射线衍射仪分析了陶瓷膜的相成分，并通过Hank’s体液模拟试验研究了陶瓷膜表面形貌演变和Ca、P等元素的含量变化。研究结果表明：锆盐体系溶液中制备的陶瓷膜主要由ZrO2和MgF2组成；硅酸盐体系溶液中制备的陶瓷膜主要由MgSiO3和MgO组成。在模拟体液浸泡过程中，陶瓷膜未发生腐蚀，表明对镁合金基体具有良好的防护作用。在体液浸泡7 d至14 d，陶瓷膜表面有团状物形成；浸泡21 d后，表面出现蠕虫状的羟基磷灰石形貌；同时，陶瓷膜表面的Ca、P元素含量随浸泡时间延长逐渐增加；其中，锆盐体系溶液中制备陶瓷膜表面的Ca/P比达到1.445，接近羟基磷灰石中的Ca/P比（1.67）

Abstract:

In order to improve the corrosion resistance property and the bone biological activity of medical magnesium alloys, the ceramic coatings were prepared on AZ91D alloy by micro-arc oxidation in the solution of zirconium salt system and the silicate system solutions, respectively. The phase compositions of the ceramic coatings were analysed by XRD instrument. The surface morphologies and the distribution of calcium, phosphorus were also researched by SEM and EDS. The results show that the ceramic coating in solution of zirconium salt system mainly consists of ZrO2 and MgF2, and the ceramic coating in solution of silicate system mainly consists of MgSiO3 and MgO. No corrosion of ceramic coatings is obsevred during the Hank’s simulated tests, which indicates that the ceramic coatings can improve the corrosion resistance properties of AZ91D. The SEM observation results show that agglomerates on the surfaces of the ceramic coatings are found during the testing from 7 to 14 d, and a worm-like hydroxyapatite morphology appears on the surface after testing for 21 d. The contents of calcium and phosphorus elements on the ceramic coating surface increase gradually with the increasing of testing time, and the Ca/P ratio on the ceramic coating in solution of the zirconium salt system is 1.445, which is close to the hydroxyapatite Ca/P ratio (1.67)