钛合金表面微弧氧化—碱处理复合法制备生物涂层的研究

发布时间：2018-04-12 17:50

本文选题：钛合金 + 微弧氧化　；参考：《沈阳理工大学》2011年硕士论文

【摘要】：钛及钛合金本身具有比强度高、生物相容性和耐蚀性优良的性能,但其存在生物活性差、与骨结合时间长、在生理环境中向肌体游离金属离子等问题,因而对钛合金表面改性以完善其生物学性能引起了人们的日益重视。为了阻止钛合金金属离子向体液中游离、改善其生物活性和提高骨愈合速度,本文利用微弧氧化技术在钛合金表面制备了微弧氧化陶瓷膜,并对微弧氧化陶瓷膜进行碱处理,通过微弧氧化-碱处理复合法制备出了生物活性涂层。研究了电解液组成、浓度和电压对微弧氧化过程及陶瓷膜的影响。结果表明:单一成分的电解液不利于Ti-6Al-4V钛合金微弧氧化起弧;提高溶液中离子浓度,有利于降低微弧氧化起弧电压;不同电解质对微弧氧化电流的影响不同,提高NaAC、CaAC浓度,电流增大,而提高Na_2SiO_3浓度,电流降低;可以通过调节电解液浓度或电压来控制陶瓷膜的结构及陶瓷膜表面元素含量,通过改变电解液配方来改变陶瓷膜成分。研究了碱处理对不同成分微弧氧化陶瓷膜及其生物活性的影响。结果表明:碱处理能有效降低和消除Ti-6Al-4V钛合金微弧氧化陶瓷膜表面的Al和V,从而避免陶瓷膜植入生物体内后所带来的危害;样品经碱液处理后具有良好的生物活性,在模拟体液(SBF)中浸泡2d即有一层羟基磷灰石(HA)膜形成,HA膜的迅速形成能防止陶瓷膜的溶解,有效阻止陶瓷膜表面对生物体有害元素的渗出;碱液理后,含钙磷微弧氧化陶瓷膜的生物活性优于含钙微弧氧化陶瓷膜的生物活性。研究了碱处理工艺(时间、温度、浓度)对微弧氧化陶瓷生物活性的影响。结果表明:在80°C 3mol/ NaOH的溶液中处理0.5～2h所制备的生物陶瓷膜最为优异。探讨了碱处理诱导微弧氧化陶瓷膜沉积HA的机理。分析表明:碱处理促使微弧氧化陶瓷膜表面生成钛酸钠水凝胶和羟基磷灰石是陶瓷膜具有优良生物活性的主要原因。
[Abstract]:Titanium and titanium alloys have high specific strength, good biocompatibility and corrosion resistance, but they have some problems such as poor bioactivity, long time of binding to bone, free metal ions in physiological environment and so on.Therefore, the surface modification of titanium alloys to improve their biological properties has attracted increasing attention.In order to prevent titanium alloy metal ions from dissociating into body fluid, to improve its biological activity and to improve bone healing speed, microarc oxidation ceramic film was prepared on titanium alloy surface by micro-arc oxidation technique, and the ceramic membrane was treated with alkali.The bioactive coatings were prepared by microarc oxidation and alkali treatment.The effects of electrolyte composition, concentration and voltage on the process of micro-arc oxidation and ceramic film were studied.The results show that the single component electrolyte is unfavorable to arc starting of Ti-6Al-4V titanium alloy by micro-arc oxidation, increasing ion concentration in solution is beneficial to decrease arc starting voltage of micro-arc oxidation, the effect of different electrolytes on the arc oxidation current is different, and the concentration of NaAC-CaAC is increased.The structure of ceramic membrane and the content of elements on the surface of ceramic membrane can be controlled by adjusting the concentration or voltage of electrolyte, and the composition of ceramic membrane can be changed by changing the composition of electrolyte.The effect of alkali treatment on the microarc oxidation ceramic membrane and its biological activity was studied.The results show that alkali treatment can effectively reduce and eliminate Al and V on the surface of ceramic membrane of Ti-6Al-4V titanium alloy micro-arc oxidation, thus avoiding the harm caused by ceramic membrane implanted into organism, and the sample has good biological activity after alkali treatment.After soaking in SBF for 2 days, there was a layer of hydroxyapatite (HA) membrane formed rapidly, which could prevent the dissolution of ceramic membrane and prevent the exudation of harmful elements on the surface of ceramic membrane, and after lye treatment, the formation of HA membrane could prevent the dissolving of ceramic membrane and prevent the exudation of harmful elements on the surface of ceramic membrane.The bioactivity of the ceramic membrane containing calcium and phosphorus was better than that of the ceramic membrane containing calcium.The effects of alkali treatment (time, temperature and concentration) on the bioactivity of micro-arc oxidation ceramics were studied.The results showed that the bioceramics membrane prepared in 80 掳C 3mol/ NaOH solution for 2 h was the best.The mechanism of HA deposition on micro-arc oxidation ceramic membrane induced by alkali treatment was discussed.The results showed that alkali treatment promoted the formation of sodium titanate hydrogel and hydroxyapatite on the surface of ceramic membrane.
【学位授予单位】：沈阳理工大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TG174.45

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