溶液钙浓度和微弧氧化频率对微弧氧化膜层形貌和组成的影响

Ti6A14V合金在不同钙磷浓度的电解液中和不同微弧氧化频率下进行微弧氧化制得氧化膜.采用SEM观察微弧氧化膜微观形貌,使用EDS、XRD分析膜层成分和相组成.结果表明:电解液中钙磷元素浓度直接影响制得氧化膜层中的钙磷元素含量与Ca/P比,且随电解液中Ca元素浓度增加而增加;当频率降低时,氧化膜表面孔洞直径变大且氧化膜中Ca元素含量与Ca/P比都升高;而氧化膜中P元素随频率降低而降低.     

钙磷含量对TA2医用钛合金微弧氧化膜层的影响

在不同钙磷原子比的硅酸盐电解液中,通过微弧氧化技术在钛合金的表面制备陶瓷膜层,研究了溶液中钙磷原子比对膜层结构和成分的影响,并讨论了膜层形成机理。结果表明,膜层中的元素含量与电解液中的元素含量为非线性关系;钙磷原子比为8时,膜层中的钙磷原子比接近羟基磷灰石。此外,电解液浓度增加增大膜层表面粗糙度。     

纯钛表面微弧氧化多孔陶瓷膜的结构特性

采用微弧氧化处理技术和电解液成分的优化设计,在纯钛表面制备了含钙磷的多孔复合陶瓷膜,并考察了陶瓷膜的表面形貌、截面形貌、化学成分、物相构成、生物活性及其与基体的结合强度等特性。研究结果表明:纯钛表面微弧氧化后形成了凹凸不平的多孔陶瓷膜,整个膜层分为表层疏松层、中间过渡层和内部致密层三个区域,总厚度为25～40μm,膜层与基体的界面呈"锯齿状"紧密结合。膜层主要由金红石相TiO2和锐钛矿相TiO2构成;膜层中含有Ca,P,O,Ti四种元素,其钙磷比ω(Ca)∶ω(P)为1.528;膜层中的Ti,Ca,P元素呈梯度分布,由表及里Ti含量逐渐增多,Ca和P含量逐渐减少,O元素分布比较均匀。含钙磷多孔复合陶瓷膜具有良好的生物活性,样品经碱液处理后再在快速钙化溶液(FCS)中浸泡4d即有羟基磷灰石(HA)形成;膜层与基体具有高的结合强度,在450V和600Hz时膜层的临界载荷值高达29.5N。     

阳极电压对医用钛材微弧氧化的影响

采用恒压模式微弧氧化对医用钛材表面改性，制备出含钙磷的TiO2复合膜层，借助于SEM、XRD和EDS研究了阳极电压对膜层的形貌、相组成和钙磷含量的影响，探讨了膜层表面和孔内钙磷的分布规律。研究结果表明，低压处理获得小孔径和锐钛矿型TiO2为主的膜层，钙磷含量和钙磷比较低，并且微孔内的钙磷含量少于膜层表面。随着阳极电压的提高，膜层的孔径增大，金红石型TiO2增多，钙磷含量和钙磷比增大。高压处理时微孔内的钙磷含量与膜层表面相当。提高微弧氧化恒压电压，可以促进Ti氧化反应。经过微弧氧化后的Ti表面多孔形貌、晶型和钙磷含量将对后续的水热处理羟基磷灰石的生成有重要影响。     

用微弧氧化技术处理医用钛合金表面的研究

采用微弧氧化对钛合金表面改性，讨论在不同条件下微弧氧化膜的形貌、结构和成份。结果表明，在钛合金表面得到一层金红石型TiO2和锐钛矿型TiO2的多孔氧化膜，且在膜中可以渗入钙，磷离子。膜层中的元素呈阶梯分布，外层的Ca,P含量较大，Ca/P含量随溶液中Ca/P含量近似呈线性增强。在确定的电解液下表面孔隙率基本不变，但孔洞大小随反应电压的增加而增加；膜的生长速率随反应时间的延长呈先快后慢变化。这种含有Ca，P成份的多孔表层结构有利于骨细胞的吸附和结合。     

电解液成分对纯钛表面微弧氧化膜结构与生物活性的影响

采用微弧氧化处理技术,在纯钛TA2表面制备了含钙磷的多孔复合氧化膜,用SEM、XRD、EPMA等分析了电解液成分对氧化膜形貌、成分、相构成及生物活性的影响。结果表明:纯钛表面微弧氧化后原位生成的含钙磷多孔性复合氧化膜由锐钛矿相TiO2,金红石相TiO2和基体Ti组成;随电解液中钙磷摩尔比(Ca/P)值的增大,表面孔洞数量增多、直径变小,膜中Ca/P值增大,锐钛矿相TiO2减少、金红石相TiO2增多;当电解液中Ca/P=5时得到的氧化膜的Ca/P值为1.528,将该样品经碱液处理后再在快速钙化溶液(FCS)中浸泡2 d后即有羟基磷灰石HA形成,表明其具有良好的生物活性。     

水热处理液配方对羟基磷灰石生长的影响

将Ti6-A14-V放入含有钙磷元素的溶液中进行微弧氧化处理,在其表面可以生成一层含有钙磷元素的氧化膜.针对钙磷元素含量以及分布在微弧氧化过程中不容易控制的问题,对水热处理液进行改进,在改进的水热处理液中进行水热处理.结果表明:氧化膜表面上羟基磷灰石在数量、尺寸以及均匀性上都有很大提升.     

电解液中钙磷组分对镁合金MAO生物陶瓷膜层特性的影响

采用恒流模式,通过单变量实验改变电解液中乙酸钙、六偏磷酸钠和磷酸二氢钠等钙磷组分的浓度,在AZ31镁合金表面制备微弧氧化生物陶瓷膜,观察分析膜层微观组织结构,测定膜层表面Ca/P比、耐蚀性等,探讨钙磷组分及其浓度对膜层组织和性能的影响,进而对电解液进行优化,并对优化后的膜层性能进行观察和分析。结果表明:乙酸钙、六偏磷酸钠、磷酸二氢钠对膜层Ca、P元素含量及Ca/P比值有决定作用;乙酸钙浓度越高,膜层厚度越小,但是均一性越好;六偏磷酸钠浓度对膜层表面形貌和厚度几乎无影响,其浓度越高,膜层中P元素含量越高;磷酸二氢钠浓度越高,Ca/P比值越小。电解液优化后,制备的膜层较为平整致密,表面均匀分布10.7μm左右的微孔,但存在微裂纹;膜层主要由MgO、Mg和少量Ca2P2O7、SiO2等物相组成,使硬度和耐蚀性比镁合金基体有明显提高;膜层粗糙度Ra=0.45μm,润湿角为42.65°,有利于细胞的附着与生长。     

水热时间对钛合金微弧氧化膜合成羟基磷灰石的影响

目的研究水热时间对TC4钛合金微弧氧化膜合成羟基磷灰石(HA)的影响。方法对TC4钛合金微弧氧化膜进行不同时间的水热合成处理,分析其微观形貌、成分及相结构,观察其在模拟体液中浸泡5周后的形貌及结构变化。结果水热处理提高了微弧氧化膜的Ca/P摩尔比,使非晶态钙磷化合物转化为HA晶体,随着水热时间的延长,HA衍射峰数量增多且强度增加。在模拟体液中浸泡5周后,微弧氧化膜表面仅有微量磷酸钙形成,而如水热合成后再浸泡,氧化膜表面的HA几乎完全转化为磷酸钙。结论水热处理有助于钛合金微弧氧化膜表面合成HA晶体。在8 h内,水热时间越长,氧化膜表面的HA含量越高,模拟体液中浸泡后形成的磷酸钙也越多,与人体的相容性越好。     

微弧氧化电压对钛基氧化膜成分及生物活性的影响

采用微弧氧化法在纯钛表面制备了多孔钛氧化膜并进行表征。室温条件下,采用200V至350V恒压模式以0.5mol/L磷酸溶液作为电解液进行微弧氧化实验。FESEM分析表明,不同电压下,微弧氧化法制备出的氧化膜层均为多孔结构,孔径分布随电压的升高而增大。XRD和XPS分析表明,在强烈的微弧放电过程中,纯钛表面生成了TiO2和TiP2O7,随着电压的增高,TiO2的结晶度和磷元素的含量逐渐升高。体外实验表明,羟基磷灰石的沉积主要归因于样品表面含有大量可分解成HPO24?的TiP2O7,HPO24?离子被吸附到样品表面成核。约4at%磷元素能促进羟基磷灰石的生成。     

Surface characteristics of anodized and hydrothermally treated titatnium with an increasing concentration of calcium ion

Titanium is widely used as an implant material due to its good mechanical properties and the excellent biocompatibility of the oxide film on the surface. To modify the unstable oxide surface of pure titanium, plasma electrolytic oxidation was applied in this study. The electrolyte used for anodizing was a mixture of GP (glycerophosphate disodium salt) and CA (calcium acetate). In addition, a hydrothermal treatment was performed to precipitate a calcium phosphate crystal on the titanium oxide layer for bioactivity. The effect of the CA concentration of the electrolyte on the surface of titanium was investigated, with CA concentrations at 0.1 M, 0.2 M, and 0.3 M. A high concentration of CA results in a low breakdown voltage; hence many large micropores were formed on the anodized surface. Moreover, the size of the HA crystals was more minute in proportion to the increasing concentration of CA. The crystal phase of titanium dioxide was mainly anatase, and a rutile phase was also observed. As the size and/or amount of HA crystals increased, the surface roughness increased. However, the surface roughness could be decreased by fully and uniformly covering the surface with HA crystals. The corrosion resistance in the saline solution was increased by anodic spark oxidation. In addition, it was slightly increased by a hydrothermal treatment. It is considered that a more stable and thicker titanium oxide layer is formed by anodic oxidation and a hydrothermal treatment.     

电解液钙磷含量对医用TC4钛合金微弧氧化膜的影响

研究钙磷原子比不同时,电解液中乙酸钙和多聚磷酸钠的浓度对TC4钛合金微弧氧化陶瓷膜形貌、钙磷原子比及相结构的影响。结果表明:在电解液中Ca、P原子比为1.3~1.8、乙酸钙浓度为20~40 g/L时,可以在钛合金表面制备多微孔结构的陶瓷膜;其表面含有一定比例的钙、磷元素,并可以通过改变电解液的钙磷原子比和乙酸钙与多聚磷酸钠的同比浓度来调整陶瓷膜钙、磷的含量和比例;陶瓷膜主要是由锐钛矿型和金红石型二氧化钛构成,当电解液乙酸钙和多聚磷酸钠的浓度提高时,金红石型二氧化钛比例提高。     

Electrochemical deposition of hydroxyapatite coatings on titanium

1 Introduction Titanium implants have been used widely for various types of bone-anchored reconstructions due to their excellent corrosion resistance and mechanical properties. However, titanium exhibits poor osteoinductive properties, fortunately, which…     

Effect of Electrolytic Solution Concentrations on Surface Hydrophilicity of Micro-Arc Oxidation Ceramic Film Based on Ti6Al4V Titanium Alloy

在不同电解液浓度的钙盐和磷酸盐混合体系中对Ti6Al4V合金进行微弧氧化(MAO)以改善其微观结构和亲水性能。利用扫描电镜、X射线衍射仪、测厚仪以及电化学工作站等对生成膜层的显微结构、物相组成、厚度以及亲水性能进行研究。结果表明:所制备的微弧氧化膜表面为粗糙多孔结构,含锐钛矿、金红石以及少量羟基磷灰石。随磷酸二氢钾浓度升高,羟基磷灰石相增多;微弧氧化膜厚度增大到一定值后不再发生变化;微弧氧化致密层与疏松层比例发生变化,增厚的疏松层表面多孔,且有较多含Ca、P的羟基磷灰石相,陶瓷膜的亲水性能提高,使得微弧氧化陶瓷膜的生物相容性得到提高。     

纯Ti表面微弧氧化-碱热处理仿生陶瓷膜的制备及耐蚀性

采用微弧氧化-碱热处理在纯Ti表面制备了含有羟基磷灰石(HA)的仿生陶瓷膜。利用SEM,XRD和电化学工作站等手段研究了膜层的形貌、物相及其耐蚀性。结果表明:在乙酸钙-磷酸二氢钙电解液体系中微弧氧化(MAO),纯Ti表面形成一层含Ca和P的TiO2多孔陶瓷膜。经水热处理后,膜层表面的孔洞变小、致密性增加,膜层中还出现了鳞状、层片状以及针棒状的HA。在Hank's模拟体液中,MAO膜和微弧氧化-碱热处理(MAOAH)膜均表现出较好的耐蚀性。MAO膜经模拟体液腐蚀后,形成了缺钙型HA(Ca8.86(PO4)6(H2O2)2)和CaTiO3;而模拟体液中的阴离子与MAOAH膜层的氧化物作用使膜层孔洞直径和深度增加。     

Effects of anodizing voltage on the anodized and hydrothermally treated titanium surface

Anodic oxidation is the process of creating a titanium oxide layer with various defects more dense and stable. In this study, a dense, stable and porous oxide layer was formed using anodic spark oxidation on pure titanium surface and hydroxyapatite crystals were formed on its surface via a hydrothermal treatment. A mixture of 0.02M−GP (Glycerolphosphate disodium salt) and 0.2M-CA (Calcium acetate) was used as an electrolyte. By increasing the anodizing voltage to 220, 260, 300, and 360 V, the effects of the anodizing voltage were examined by evaluating the film properties after anodization and a hydrothermal treatment. Breakdown occurred around 230 V. As the voltage increased after breakdown, the pore size increased. After the hydrothermal treatment, the amount of HA crystal precipitation was also increased as the voltage increased. The mean surface roughness (Ra) of the anodizing surface was also increased as the voltage increased. The Ra value was larger in the hydrothermally treated group compared with the group treated with anodization as a result of the HA crystals present on the surface after the hydrothermal treatment. Corrosion resistance of the surface modified by anodization was significantly increased in a saline solution compared to that for the non-treated group; this increased further after the hydrothermal treatment. These increases were most likely due to a thick stable oxide layer formed through anodization. Thus, it is believed that titanium with its surface modified through anodic spark oxidation would be a suitable biomaterial due to its corrosion resistance and biocompatibility.     

Fabrication of CTP/HAp novel gradient composite bioceramics

Calcium-titanium-phosphate（CaTi4（PO4）6, CTP）/hydroxyapatite（HAp） is a kind of novel gradient composite bioceramics, which has excellent biocompatibility and bioactivity. CTP ceramic film was synthesized one-step on the surface of titanium using micro-arc oxidation（MAO）. The CTP/HAp composite bioceramics were prepared by soaking CTP film in HAp inducing solution for several days. XRD, SEM and EDX were used to characterize the bio-ceramic films phase and composition, morphology and component. The influence of electrolyte molar ratio of Ca to P and the current density to the synthesis of film was studied, and the optimized value of parameters above were 1/6 and 15A/dm^2. The parameters of HAp inducing solution, such as component and pH value were also studied and the best pH value which is adjusted by NaOH is 6.4.