镁合金表面超声微弧氧化载氟生物涂层耐磨性和耐蚀性

Wear and Corrosion Resistance of Ultrasound Micro-arc Oxidized Fluorine-Carrying Biological Coating on Surface of Magnesium Alloy

目的提高医用镁合金微弧氧化涂层的耐蚀性、耐磨性,并赋予涂层抗菌性和生物活性。方法镁合金表面采用超声微弧氧化技术,在镀液中加入0.4、1.4、2.4、3.4 g/L的Na F,制备载氟生物涂层。通过SEM观察载氟对涂层表面形貌的影响,分析涂层的主要元素变化,进行了涂层厚度、孔隙率、拉伸强度的测定,并进行了摩擦磨损实验、电化学腐蚀实验、覆膜抗菌实验,评价了不同载氟生物涂层的结合性能、耐磨性能、耐蚀性和抗菌性。结果适量载氟生物涂层表面分布了均匀的孔隙。随着NaF浓度的增加,涂层中氟元素的含量升高,涂层厚度也随之增加,且涂层的结合强度提高了3.5~10.0 MPa。氟元素可促进涂层表面氧化物反应膜的形成,有利于减轻粘着磨损,使摩擦系数降低了0.17~0.35。载氟涂层的自腐蚀电位提高了95~170 m V,而自腐蚀电流降低约两个数量级,涂层抗菌率为61%~76%。结论超声微弧氧化镀液中添加Na F,提高了涂层结合强度、耐磨性、耐腐蚀性,涂层具有一定的抗菌性,实现了生物涂层的多功能性。

The work aims to acquire an antibacterial and biological coating and improve wear and corrosion resistance of micro-arc oxidized coating on magnesium alloy.Fluorine-carrying biological coating was prepared on magnesium alloy by adding 0.4 g/L,1.4 g/L,2.4 g/L and 3.4 g/L Na F in plating solution by virtue of ultrasonic micro-arc oxidation technology.Effects of fluorine-carrying on surface morphology of the coatings was observed major element change of the coatings was analyzed,and coating thickness,porosity and tensile strength were determined by using scanning electron microscopy.Friction and wear test,electrochemical corrosion experiment and film-coated antibacterial experiment were performed.Binding,wear,corrosion and antibacterial properties of different fluorine-carrying biological coatings were evaluated.Holes were distributed uniformly on the surfaces of fluorine-carrying biological coating.As the Na F concentration increased,both the fluorine content and coating thickness increased,and the bonding strength of coating increased by 3.5~10.0 MPa.Fluorine could promote the formation of oxide film on coating surface and reduce the adhesive wear,hence the friction coefficient decreased by 0.17~0.35.The self-corrosion potential of fluorine-carrying coating increased by 95~170 m V while the corrosion current density decreased by about two orders of magnitude.The antibacterial rate was 61%~76%.The bonding strength,wear and corrosion resistance of fluorine-carrying biological coating are greatly improved by the addition of Na F into ultrasonic micro-arc oxidation bath,and the coating is of certain antibacterial property,which realizes the versatility of biological coating.