医用钛合金微弧氧化复合陶瓷膜层断裂力学研究

以Ti6Al4V钛合金为基体材料,通过微弧氧化方法在电解液中制备多孔氧化锆和羟基磷灰石复合医用钛合金陶瓷膜层.利用能谱分析仪、扫描电镜和X-射线衍射仪分析膜层结构及相组成特点.对试样断裂韧性进行测量试验,通过测试结果对膜层断裂韧性进行了分析研究.探究了氧化锆对于钛合金羟基磷灰石膜层的增韧机制,并建立了适于多孔微裂纹膜层材料断裂韧性数学模型.结果表明,ZrO2/羟基磷灰石医用钛合金复合陶瓷膜层比单一的羟基磷灰石陶瓷膜层具有更好的断裂韧性.     

富含钙磷的多孔氧化钛膜及其生物活化机理

在不同电压下,钛经微弧氧化在表面形成富含钙磷的多孔氧化钛膜。通过模拟体液浸泡实验检测磷灰石的形成以确定样品的生物活性。实验结果表明：不同电压制备的微弧氧化样品在模拟体液浸泡后,只有400 V和450 V的样品表面生成磷灰石层,说明高电压制备的样品具有生物活性;而低电压制备的微弧氧化样品在模拟体液中浸泡长达50 d仍未见到任何物质沉积,表明其不具有生物活性。分析认为,粗糙多孔的表面虽有利于磷灰石的成核,但高电压下出现的CaTiO_3相及其水解吸引钙、磷沉积才是磷灰石形成的主要原因。     

Ti75钛合金微弧氧化膜的制备及性能

在含硅酸钠10g/L、六偏磷酸钠2g/L、柠檬酸钠2g/L和添加剂4g/L的电解液中,以微弧氧化技术在Ti75钛合金的表面成功制备了微弧氧化膜。采用涡流测厚仪、扫描电镜、X射线衍射仪、显微硬度计等手段研究了微弧氧化电压和时间对钛合金微弧氧化膜厚度的影响,分析了氧化膜层的表面形貌、组成、硬度、耐蚀性能及高温性能。结果表明,微弧氧化膜层主要由金红石型和锐钛矿型二氧化钛组成。氧化电压升高,膜层厚度增加;氧化时间延长,初期膜层厚度增加明显,20min后膜厚增加减缓。经微弧氧化处理后,钛合金的硬度、耐蚀性能和高温抗氧化性能均得到了明显改善。     

钛合金微弧氧化钙磷生物膜层形成机制研究

为了利用微弧氧化工艺生成钛合金生物钙磷陶瓷涂层,使用微弧氧化电源,在恒电流条件下制备试样。通过电子扫描电镜和电子能谱仪观测不同氧化阶段涂层形貌和元素组成,膜层厚度变化特点,并分析各阶段微弧放电特性,研究了钛合金微弧氧化生成羟基磷灰石(钙磷)医用陶瓷涂层机制。结果表明,各阶段膜层放电特性不同,膜层先向外生长,后向内生长,且所生成膜层元素成分有区别,致使在微弧放电阶段才有钙磷生物成分生成。结论:若想获得高质量钙磷生物膜层,需使微弧氧化达到微弧放电阶段,但应避免进入弧光放电阶段,所得结论可对研究微弧氧化成膜过程起到一定的指导作用。     

氧化时间对钛合金微弧氧化膜性能的影响

研究了在含钙、磷的电解液中氧化时间对Ti6Al4V钛合金微弧氧化生物活性膜的厚度、粗糙度、表面形貌、相成分及氧化膜与基体结合力的影响。结果表明,氧化t低于12min时,随着氧化时间增加,微弧氧化膜的厚度增加、表面粗糙度增大、微观孔洞变大、膜层中钙磷含量及钙磷比增大、氧化膜与基体的结合力增强。氧化t为12min时膜层与基体的结合力较好,约30N。氧化t超过12 min以后,膜层表面出现裂痕,与基体的结合力减小。     

一种去除钛及钛合金微弧氧化膜的碱性退膜液

为了减少钛及钛合金材料表面处理过程中的吸氢和满足清洁生产的要求,研制开发了一种用于去除钛及钛合金微弧阳极氧化膜的碱性退膜液,对这种退膜液的退膜效果和稳定性能进行了研究,并进一步考察了退膜液对钛及钛合金基体的腐蚀性能、退膜后重新微弧氧化的难易以及微弧氧化膜与基体的结合情况。实验表明:该退膜液具有退膜效果好、稳定性能好、不影响上膜及膜层与基体结合的特点,为完善钛及钛合金微弧氧化工艺及其它钛及钛合金阳极氧化膜退膜液的开发提供了有价值的参考。     

钛合金低温脉冲微弧阳极氧化技术

本项研究确定了防止钛合金与其它活泼金属接触时发生电偶腐蚀，防止粘结，提高其表面硬度，减少摩擦磨损的脉冲微弧阳极氧化工艺。微弧阳极氧化在L（含硫化合物）、T（含磷化合物）及若干添加剂的混合电解液中进行。由脉冲电源供电。高压、高热的微弧使零件表面发生等离子体放电现象，形成2μm-15μm致密的、高绝缘的氧化膜层。具有抗腐蚀、防粘结的功能；同时，钛合金的表面硬度得到大幅度提高。     

多孔双相钙磷钛合金微弧氧化膜层的制备及生物相容性

为克服钛合金生物膜层单一相的缺陷,以Ti6A14V合金为基体,用微弧氧化法制得具有双相钙磷复合陶瓷膜层(BCP)的钛合金器件.通过控制工作液成分制得由不同比例的β-磷酸三钙(β-TCP)和羟基磷灰石(HA)组成的多孔性复合膜层.研究了电源占空比对BCP膜孔隙率和孔径大小的影响.采用能谱仪和X射线衍射仪分析了BCP膜层的...     

溶胶-凝胶法二氧化钛薄膜诱导沉积磷酸钙层

碳／碳复合材料作为骨植入材料具有良好的生物力学相容性，但没有生物活性。以玻璃片为基板进行预试，发现溶胶凝胶法制备的锐钛矿型二氧化钛薄膜呵在快速钙化溶液中诱导沉积出由磷酸八钙和羟基磷灰石组成的磷酸钙层，二氧化钛薄膜的微观形貌对快速钙化溶液中磷酸钙沉积物的沉积速度和组成影响不大。在以上预试的基础上，通过溶胶凝胶法制备的二氧化钛薄膜在碳/碳复合材料上复合了生物活性磷酸钙涂层。     

Ti6Al4V钛合金表面蓝色微弧氧化膜的制备及性能

利用微弧氧化技术在Ti6Al4V钛合金表面制备出蓝色微弧氧化膜。对微弧氧化膜的微观形貌和元素组成进行了分析,并对微弧氧化膜的显微硬度进行了测试。结果表明:微弧氧化膜表面光整,呈均匀深蓝色,其主要由Ti、Mn、O和C四种元素组成,还含有少量的V、Al和Si元素;微弧氧化膜的表面粗糙度约为0.159μm,与钛合金的表面粗糙度相近;微弧氧化膜的显微硬度为5 437.4 MPa,显著高于钛合金的显微硬度。     

Hydrothermal nucleation of hydroxyapatite on titanium surface

Titanium plates were submitted to nucleation and growth of hydroxyapatite (HAp) under hydrothermal conditions. A group of these plates were submitted to nucleation without any previous treatment and another group was treated with NaOH 1 M at 130°C inside an autoclave followed by heat-treatment at 600°C. The nucleation were performed by soaking all these titanium pieces, in a simulated body fluid (SBF) solution, containing calcium, phosphate and other ions, in order to promote the nucleation and growth of hydroxyapatite under hydrothermal conditions on the titanium surface. The results show that hydrothermal nucleation and growth of HAp occurs even on the non-treated titanium surface at 150°C. However, a better uniformity of the hydroxyapatite layer was observed on the pre-treated titanium surface, at 80°C, with the renewal of the SBF solution.     

Hydrothermal-Electrochemical Formation of BaTiO, Films: Electrochemical Characterization of the Early Stages of Growth

The formation mechanism of BaTiO, films produced by a hydrothermal-electrochemical method was characterized using electrochemical techniques. Experiments were conducted in a three-electrode electrochemical cell, with titanium foil as the working electrode and Ag/AgCl as the reference electrode, in a 0.25 M Ba(OH)₂ solution at 150°C. Hydrothermal-electrochemical BaTiO, film formation is initially controlled by charge transfer related to the rate of electrochemical oxidation of titanium. The process later becomes mass transfer controlled, presumably related to the diffusion of Ba²⁺ ions across the built-up BaTiO₃ film. A relation between the mechanism of formation of BaTiO, films under both the hydrothermal-electrochemical and the pure hydrothermal methods was established.     

Hybrid Process of Microarc Oxidation and Hydrothermal Treatment of Titanium Implant

A duplex process was proposed with which a titania containing calcium and phosphate on the surface of titanium alloy was formed by microarc oxidation in aqueous electrolytes, and finally converted to bioactive layer containing hydroxyapatite by subsequent hydrothermal synthesis. The layer is porous in micro scale and composed of crystals in nanometer size. There was no distinct interface between the hydroxyapatite layer and the substrate.     

Pulsed laser deposition of hydroxyapatite-diamondlike carbon multilayer films and their adhesion aspects

We have developed a layered hydroxyapatite/diamondlike carbon/functionally gradient diamondlike carbon-silver/titanium carbide/titanium carbonitride/titanium nitride composite film using pulsed laser deposition. A diamondlike carbon interlayer between a hydroxyapatite coating and the Ti-6Al-4V alloy can serve several purposes, including preventing corrosion of Ti-6Al-4V alloy, overcoming poor adhesion between the hydroxyapatite coating and the titanium oxide surface, and reducing inflammation at the implant/tissue interface. Titanium nitride, titanium carbonitride (TiC _x N _y ), titanium carbide and functionally gradient diamondlike carbon-silver layers were used to improve the adhesion of diamondlike carbon films to Ti-6Al-4V alloy. We envision several potential medical applications for these multilayer materials, including use in orthopedic and dental devices.     

水热合成二氧化钛薄膜及其光催化性能的研究

本文采用水热合成法制备纯二氧化钛薄膜。在紫外光的照射下,以亚甲基蓝溶液为目标降解物。考察了水热合成反应温度,反应时间,原料浓度等对二氧化钛薄膜光催化性能的影响,确定了TiO2薄膜的适宜水热合成条件。利用XRD对二氧化钛的晶体结构进行表征。     

TiO2/羟基磷灰石复合微球的合成

将乙酰丙酮稳定的钛酸四正丁酯分散到含有硬脂酸的水中,接着加入Ca²⁺、H₂PO₄^-源,然后通过150℃的水热过程,合成了TiO₂/羟基磷灰石(HAP)复合微球。其中的硬脂酸作为界面媒介吸附Ca²⁺,确保生成的羟基磷灰石的粒子吸附在分散的钛酸四正丁酯球形"油滴"表面。经水热过程,分散的油滴转化为TiO₂ 为内核,HAP为壳层的复合微球。HAP粒子组成的微球外壳层对内核钛酸四正丁酯水解及缩聚反应而引起的体积收缩产生抑制作用,从而对最终的TiO₂ 内核的微结构产生影响。亚甲基蓝的紫外光催化降解实验结果表明,复合微球的光催化性能与微球对亚甲基蓝的平衡吸附量有密切的关系,并取决于产品的微结构。当复合微球中羟基磷灰石的理论质量分数为1%~1.5%时,微球对亚甲基蓝显示了较高的光催化降解效率。     

Effect of Precursor Pyrolysis on the Dielectric Properties of Hydrothermally Derived Barium Titanate Thin Films

BaTiO₃ thin films were processed hydrothermally on Ag-coated quartz substrates at 90°C by reacting films of titanium dimethoxy dineodecanoate (TDD) in aqueous solutions of Ba(OH)₂. Two reaction sequences were used: either the TDD was reacted directly in aqueous Ba(OH)₂, or the TDD was first pyrolyzed in air at temperatures ranging from 200° to 500°C before hydrothermal reaction. Depending on the processing conditions, the dielectric constant of the thin films ranged from 5 to 170, the dielectric constant increasing with increasing pyrolysis temperature. Thin film porosimetry data suggest that the improvement in film dielectric performance is related to decreases in thin film residual porosity after hydrothermal reaction.     

新型无机高效抗菌材料的研制

以羟基磷灰石(HAP)为载体,采取共沉淀和离子交换法制备钛/金属离子(Ag+,Cu2+,Zn2+)复合羟基磷灰石(H APTiM)无机高效抗菌材料技术,依据XRD表征,确定不改变HAP结构,最佳钛的掺杂量为XTi =Ti原子数/(Ca +Ti)原子数=0.1,并通过UV - vis漫反射吸收光谱对该材料进行了表征.金黄...     

Hydrothermal Formation of Hydroxyapatite Layers on the Surface of Type-A Zeolite

Type-A zeolite evenly covered with hydroxyapatite thin layers was prepared using hydrothermal treatment at 120°C for 8 h under autogenous pressure. The hydroxyapatite needlelike nanocrystals, 100–200 nm in diameter and 30 nm in thickness, were grown under the reaction between discharged Ca²⁺ ions from type-A zeolite and PO₄³⁻ ions in (NH₄)₃PO₄ solution. The preferential orientations of the c -axis of hydroxyapatite crystals perpendicular to a zeolite surface were observed using transmission electron microscopy. The crystal structure of type-A zeolite was not destroyed under the reaction, but the surface morphology was changed only with complete covering of scaly hydroxyapatite particles.     

纳米TiO2薄膜制备方法的研究进展

纳米二氧化钛以其优异的化学、物理性能受到关注。薄膜是纳米二氧化钛的重要形式,制备纳米二氧化钛薄膜具有重要意义和很好的应用前景。依据制备工艺中温度的要求,对制备纳米二氧化钛薄膜的方法进行了概述,高温制备的工艺主要有溶胶-凝胶法、水热法、气相沉积法,低温制备工艺主要有电泳沉积法、紫外光照射法、电化学制备法、模板自组装制备法。