TC4钛合金微弧氧化因素对生物陶瓷膜中Ca,P相对含量的影响

为了提高钛合金陶瓷膜的生物相容性,采用微弧氧化技术在TC4钛合金表面制备了一层富含Ca,P的生物活性陶瓷膜。采用SEM,EDS,XRD研究了电流密度、溶液中Ca,P摩尔比、添加剂EDTA.2Na浓度对膜层中Ca,P相对含量(原子分数)及Ca,P摩尔比的影响及微弧氧化生物陶瓷膜层的形貌及组成。结果表明:随着电流密度的增大,膜层中的Ca,P相对含量增加,Ca,P摩尔比也逐渐增加;增大溶液中Ca,P摩尔比,膜层中Ca相对含量有所增加,Ca,P摩尔比也逐渐增加;当加入添加剂EDTA.2Na时,膜层中的Ca相对含量显著增加,从而使膜层中Ca,P摩尔比显著增加;氧化膜由致密的内膜层和多孔的外膜层构成,主要由Ca,P,O,Ti,V元素组成,其相成分主要为金红石和板钛矿型TiO2,并含有一定量的非晶相Ca,P化合物。

Effect of Micro-Arc Oxidation Conditions on Ca and P Contents of Bio-Ceramic Coating on TC4 Titanium Alloy

Bioactive ceramic coating containing Ca and P was prepared on TC4 titanium alloy by micro-arc oxidation(MAO).The morphology and composition of as-prepared MAO coatings were analyzed by means of scanning electron microscopy,energy dispersive spectrometry and X-ray diffraction.The effects of current density,molar ratio of Ca and P in electrolyte and concentration of additive(EDTA·2Na) on the contents of Ca and P and Ca/P molar ratio of the MAO coatings were studied.It was found that the contents of Ca and P and Ca/P molar ratio of the MAO coatings increased with increasing current density.Increasing Ca/P molar ratio in the micro-arc oxidation solution,the content of Ca and Ca/P molar ratio of the MAO coatings increased.In the meantime,introducing EDTA·2Na into the micro-arc oxidation solution resulted in significant increase of the Ca content and Ca/P molar ratio in the MAO coatings.As-prepared MAO coatings consisted of compact inner layer and porous outer layer,and were mainly composed of Ca,P,Ti and V.The major phases of the MAO coatings included rutile and anatase TiO2,and the minor phases were amorphous compounds containing Ca and P.