纯钛微弧氧化陶瓷涂层结构调控及生物学性能

发布时间：2018-04-30 16:35

  本文选题：纯钛 + 微弧氧化　； 参考：《哈尔滨工业大学》2015年博士论文

【摘要】：本文采用微弧氧化技术在纯钛表面制备了含钙、磷、硅和钠元素的非晶相陶瓷涂层。通过多步微弧氧化处理、热处理、水热和水汽处理在所制备微弧氧化涂层表面构建了不同尺度的结构,同时对涂层的元素化合态进行了调控。采用X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、傅立叶变化红外光谱(FT-IR)、拉曼光谱(Raman)、X-射线光电子谱(XPS)、氮气吸附、压汞孔隙测试仪、纳米压痕仪和力学万能试验机等分析手段研究了表面调控前后微弧氧化涂层的组织结构、力学性能和涂层在模拟体液中诱导磷灰石的能力。通过种植体兔胫骨体内植入的实验方法,采用X射线影像、Micro-CT、硬组织切片染色、生物力学测试等分析手段研究了具有不同表面结构和元素化合态的钛种植体与骨组织的体内相容性、骨整合能力和力学行为。以EDTA-2Na、Ca(CH_3COO)_2·H_2O、Ca(H_2PO_4)_2·H_2O、Na_2SiO_3·9H_2O和NaOH的水溶液为电解液,在纯钛表面制备了含钙、磷、硅和钠元素的微弧氧化涂层(MAO涂层)。MAO涂层由非晶相和少量锐钛矿相组成,含有Ca、P、Si、Na、Ti和O元素。300V下制备的MAO涂层表面具有均匀的微观多孔结构。随电压升高,涂层厚度增加,涂层表面微孔孔径增大,微孔密度降低,涂层表面Ca、P、Si和Na元素的含量增加,Ti元素含量降低。Ti、O、Ca、P和Si元素在涂层内部存在梯度分布。以EDTA-2Na、Ca(CH_3COO)_2·H_2O、Ca(H_2PO_4)_2·H_2O、Na_2SiO_3·9H_2O、NaNO_3和NaOH的水溶液为二步微弧氧化电解液对试样进行处理,可在MAO涂层表面构建亚毫米宏孔结构,宏孔内生成了致密的Ti_3O_5氧化层。随NaOH浓度增大,宏孔密度升高,宏孔孔径减小,宏孔内氧化层增厚并引入微量的Ca、P、Si和Na元素。以EDTA-2Na、Ca(CH_3COO)_2·H_2O、Ca(H_2PO_4)_2·H_2O、Na_2SiO_3·9H_2O和NaOH的水溶液为三步微弧氧化电解液对试样进行处理,在钛表面形成了完整且具有亚毫米和微米双级孔隙结构的微弧氧化涂层。宏孔区域的涂层的微孔密度小于平坦区域,且宏孔区域涂层表面生成了Ti-OH和Si-OH官能团。热处理可调控MAO涂层表面的微米结构。MAO涂层经过800℃空气气氛热处理后,生成锐钛矿、金红石和Ca Ti_4(PO_4)_6,涂层表面形貌不变,涂层厚度增加,涂层中C元素几乎消失。经过800℃氩气保护热处理后涂层由金红石和锐钛矿组成,表面微孔结构消失,生成大量颗粒状晶体,涂层厚度增加,且在涂层与基体界面处生成β-Ti相变层。水热和水汽处理均可在MAO涂层表面构建纳米结构。水热处理过程中,涂层中Ca、P、Si和Na元素溶入溶液中。随NaOH浓度增大,HA晶体的生成量先增多后减少,OH-离子对涂层的腐蚀作用增强,涂层表面微孔结构消失,生成排布密集的H_2Ti5O11·H_2O纳米棒。水汽处理过程中,涂层表面Ca、P、Si和Na元素含量基本不变。随NaOH浓度增大,涂层厚度减小,HA晶体生成量增多但长径比减小,表面生成Ti-OH官能团。当水汽处理的NaOH浓度为1mol/L时,涂层表面出现大量(NaOH)_2(H_2O)7沉积物。在SBF浸泡过程中,MAO涂层中的Na+离子能够和SBF中的H_3O+离子发生离子交换形成Si-OH,增加磷灰石的形核。多步微弧氧化处理后试样表面宏孔区域的磷灰石诱导能力优于平坦区域的MAO涂层,原因是宏孔结构增大了试样的比表面积,有利于Si-OH的生成,且三步微弧氧化涂层宏孔区域内含有Ti-OH和Si-OH官能团,增强了磷灰石的形核能力。800℃氩气保护热处理后涂层的磷灰石诱导能力增强,原因是涂层表面形成了金红石,而金红石(101)晶面与HA(0001)晶面具有良好的晶体学匹配,可为磷灰石的形核提供良好的形核位点。NaOH溶液水汽处理后的涂层表面形成HA和Ti-OH官能团,磷灰石诱导能力明显增强。所有涂层诱导的磷灰石都含有HPO_42-和CO_32-等官能团,且表面具有纳米网状多孔结构。多步微弧氧化处理试样表面的宏孔结构可与树脂胶啮合,涂层的破坏强度明显提高。NaOH溶液水汽处理后,涂层的硬度和弹性模量基本不变,涂层内部缺陷减少,涂层的结合强度明显增大。800℃热处理后的涂层中生成脆性相,涂层的结合强度明显降低。三步微弧氧化制备的表面改性钛种植体植入兔胫骨内,体内相容性优良,在植入期间无排斥感染现象。种植体周围骨组织吸收良好,骨组织生长入种植体表面亚毫米宏孔中。种植体与骨组织的结合强度明显增强,压出种植体的表面宏孔中可观察到残留的啮合骨组织。水汽处理改性的微弧氧化钛种植体植入兔胫骨内,表现出优异的骨-种植体界面结合,骨组织沿种植体表面紧密生长。种植体与骨组织的结合强度明显增强,压出种植体表面可观察到残留骨组织。综上所述,多步微弧氧化处理、热处理、水热和水汽处理可在MAO涂层表面构建不同尺度的结构,有利于磷灰石的形成。采用三步微弧氧化处理和水汽处理的微弧氧化钛种植体展现出优异的力学性能和骨整合能力。
[Abstract]:In this paper, the amorphous ceramic coatings containing calcium, phosphorus, silicon and sodium are prepared by micro arc oxidation on the surface of pure titanium. By multistep micro arc oxidation treatment, heat treatment, water heat and water vapor treatment, the structure of different scales on the surface of the prepared micro arc oxidation coating is constructed. At the same time, the composition of the elements in the coating is regulated by X ray diffraction. Radiation (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fu Liye change infrared spectroscopy (FT-IR), Raman spectroscopy (Raman), X- ray photoelectron spectroscopy (XPS), nitrogen adsorption, mercury porograph test instrument, nano indentation instrument and mechanical universal testing machine were used to study the microstructure and force of the micro arc oxidation coating before and after the surface control. The ability to induce apatite in simulated body fluids. Through the experimental method of implantation in the rabbit tibia, X ray images, Micro-CT, hard tissue section staining, biomechanical test and other analytical methods were used to study the compatibility of titanium implants with different surface structures and elements in the body and bone tissue. With EDTA-2Na, Ca (CH_3COO) _2. H_2O, Ca (H_2PO_4) _2, H_2O, Na_2SiO_3. 9H_2O and NaOH as the electrolyte, the microarc oxidation coatings containing calcium, phosphorus, silicon and sodium are prepared on the surface of pure titanium with the amorphous and a small amount of anatase. The surface of the prepared MAO coating has a homogeneous microporous structure. With the increase of the voltage, the thickness of the coating increases, the pore size of the coating increases, the density of micropores is reduced, the content of Ca, P, Si and Na on the coating surface increases, the content of Ti elements decreases.Ti, O, Ca, P and Si elements exist in the gradient distribution of the coating. EDTA-2Na H_2PO_4) _2. H_2O, Na_2SiO_3. 9H_2O, NaNO_3 and NaOH solution are treated by two step micro arc oxidation electrolyte. The submillimeter macroporous structure can be constructed on the surface of MAO coating, and the dense Ti_3O_5 oxidation layer is formed in the macro hole. With the increase of the NaOH concentration, the macropore density is increased, the pore diameter is reduced, the oxidation layer in the macro hole is thickened and introduced into the micropore. The amount of Ca, P, Si and Na elements. The samples were treated with EDTA-2Na, Ca (CH_3COO) _2, H_2O, Ca (H_2PO_4) _2. Aqueous solution as three step micro arc oxidation electrolyte, and formed a complete micro arc oxidation coating with submillimeter and micron two-stage pore structure on the titanium surface. The micropore density of the coating in the macroporous area was small. In the flat area, Ti-OH and Si-OH functional groups are formed on the coating surface of the macroporous region. The microstructural.MAO coating on the surface of the MAO coating can be treated by heat treatment at 800 C air atmosphere. After the heat treatment, the anatase, rutile and Ca Ti_4 (PO_4) _6 are formed, the surface morphology of the coating is unchanged, the coating thickness increases, and the C element in the coating almost vanishes. After 800 degrees centigrade, the coating is almost disappeared. After heat treatment, the coating is composed of rutile and anatase, and the surface microporous structure disappears and produces a large number of granular crystals. The thickness of the coating increases, and the phase transition layer of the coating is formed at the interface between the coating and the matrix. The surface of the coating can be constructed on the surface of the MAO coating. During the hydrothermal treatment, the Ca, P, Si and Na elements in the coating are in the process of hydrothermal treatment. When the concentration of NaOH increases, the formation of HA crystal increases first and then decreases, the corrosion of the coating is enhanced by the OH- ion, the microporous structure of the coating is disappearing and the H_2Ti5O11 H_2O nanorods are formed to be dispersed. In the process of water vapor treatment, the content of Ca, P, Si and Na element in the coating surface is basically unchanged. With the increase of NaOH concentration, the thickness of the coating is reduced. Small, HA crystal production increased but the length diameter ratio decreased, and the surface generated Ti-OH functional groups. When the NaOH concentration of the water vapor treatment was 1mol/L, a large number of (NaOH) _2 (H_2O) 7 sediments appeared on the coating surface. During SBF immersion, the Na+ ions in the MAO coating could be exchanged with the H_3O+ ions in SBF and increased the nucleation of the apatite. The apatite induction ability of the macroporous area on the surface of the sample surface after micro arc oxidation is superior to the MAO coating in the flat area. The reason is that the macro pore structure increases the specific surface area of the specimen and is beneficial to the formation of Si-OH, and the three step micro arc oxidation coating contains Ti-OH and Si-OH functional groups in the macro pore region, and the apatite nucleation capacity is enhanced at.800 C argon protection. The apatite induction ability of the coating is enhanced after heat treatment, due to the formation of rutile on the surface of the coating, and the rutile (101) crystal face has a good crystallographic match with the HA (0001) crystal mask, which can provide a good nucleation site for apatite nucleation site.NaOH solution on the surface of the coating to form HA and Ti-OH functional groups, and the apatite induction ability. All coating induced apatite contains the functional groups such as HPO_42- and CO_32-, and the surface has a nano mesh porous structure. The macroporous structure of the surface of the sample surface can be meshed with the resin adhesive. The damage strength of the coating is obviously improved by the water vapor treatment of.NaOH solution, and the hardness and modulus of elasticity of the coating are basically unchanged. The internal defects of the coating decreased and the bonding strength of the coating increased obviously at.800 C. The bonding strength of the coating decreased obviously. The surface modified titanium implants prepared by three step micro arc oxidation were implanted in the tibia of the rabbit tibia, with good compatibility in the body and no rejection during the implantation. Well, the bone tissue grows into the submillimeter macroporous surface of the implant. The bonding strength of the implant and bone tissue is enhanced obviously. The residual meshing bone can be observed in the macroporous surface of the implant. The modified microarc titanium oxide implant in the water vapor treatment is implanted into the rabbit tibia, showing excellent bone implant interface and bone tissue along the implant. The bonding strength of the implant surface is close. The bond strength of the implant and bone tissue is enhanced obviously, and the residual bone can be observed on the surface of the implant. In summary, the multi step micro arc oxidation treatment, heat treatment, water heat and water vapor treatment can construct different scales on the surface of the MAO coating, which is beneficial to the formation of apatite. The three step micro arc oxidation place is used. Microarc titanium oxide implant treated with water and steam showed excellent mechanical properties and osseointegration ability.

【学位授予单位】：哈尔滨工业大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TG174.4;R318.08
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本文编号：1825314