镁合金表面HA/CNTs涂层的制备及电化学性能研究

Study of the Electrochemical Properties of HA/CNTs Coating and its Preparation on the Surface of Magnesium Alloy

为了提高生物镁合金羟基磷灰石(HA)涂层的耐蚀性能,在微弧氧化电解液中加入羟基磷灰石/碳纳米管(HA/CNTs)复合粉体添加剂,制备HA/CNTs复合涂层。分别对制备的HA/CNTs复合粉体和HA/CNTs复合涂层进行表面形貌和物相组成分析,并对HA/CNTs复合涂层在模拟体液(SBF)中的耐腐蚀性能进行了研究。结果表明,HA/CNTs复合粉体在微弧氧化过程中能均匀地沉积在镁合金表面,结晶良好且无任何杂质;与HA涂层相比,HA/CNTs涂层具有较小的腐蚀电流密度值和较大的阻抗值。此外,在SBF中浸泡4d后,HA/CNTs复合涂层表面出现大量的亚微米级颗粒产物且没有任何腐蚀裂纹。

In order to improve the corrosion resistance of the hydroxyapatite（HA）coating on biological magnesium alloy,the HA/cabon nanotubes（CNTs）composite coating was prepared by micro arc oxidation（MAO）with an electrolyte,including the composite powders of HA and CNTs.The surface morphologies and the phase compositions of the composite powder were analyzed.In addition,the corrosion resistance of the HA/CNTs composite coating in the simulation body fluid（SBF）was studied.The results show that the composite powders were well deposited on the surface of magnesium alloy during MAO process,and the HA/CNTs composite powder had good crystallinity without any impurities.Compared with HA coating,the HA/CNTs coatings had lower corrosion current density and higher impedance.A large number of sub micron scale particle deposition products were deposited on the HA/CNTs coating surface without corrosion cracks on the surface.