【作者】 吴波；

【导师】 梁成浩；

【作者基本信息】 大连理工大学 ， 化学工程， 2011， 博士

【摘要】 我国每年由于疾病及交通事故引起的骨骼和牙齿的修复与替换病例逐渐增加。植入体材料的发展已成为我国国民经济的重要组成部分。常用于制作骨骼和牙齿的植入体材料Ti6A14V合金因表面生物活性差,易产生孔蚀,并向肌体释放有害金属离子等缺陷,常导致植入体的失效。因此,对Ti6A14V合金表面进行改性已成为当今植入体材料发展的主要趋势。本文研究了Ti6A14V合金在Hank溶液、Ringer溶液和Tyrode溶液中的电化学行为,并在其表面采用三种电化学方法合成具有良好的生物活性的羟基磷灰石涂层(Hydroxyapatite,简称HA, Ca10(PO4)6(OH)2),同时对材料进行血液相容性和电化学性能研究。研究结果表明Ti6A14V合金在三种模拟体液中,随着环境温度的升高,热力学稳定性降低,维钝电流密度增大,耐蚀性下降；孔蚀动力学方程为：iHank=1.0756·(t-1.1649)-1/2,iRinger=1.0940·(t-1.4437)-1/2,iTyrode=2.0564(t-0.4568)-1/2。,孔蚀发展过程氯化物盐膜溶解控制；电化学反应的活化能分别为EaHank=45.71KJ/mol、EaRinger=155.1和Ea Tyrode=87.62 KJ/mol,属于化学反应控制。以阴极电化学沉积为基础,采用电化学牺牲阳极法在Ti6A14V合金表面制备HA涂层。HA涂层晶体呈花絮状分布,Ca/P比为1.41,厚度约15gm,结合强度为10.02MPa。通过血小板粘结实验、动态凝血时间曲线和溶血率的测定,HA涂层具有较好的血液相容性。电化学实验表明,HA涂层的耐蚀性比Ti6A14V合金有所提高。为进一步提高HA涂层的结合强度,采用微弧氧化法在Ti6A14V合金表面制备Ti02涂层,再采用阴极恒电位及水热合成法在TiO2涂层表面制备HA涂层。分布有少量圆形微孔的Ti02涂层厚度约为6μm。HA涂层呈片状,Ca/P比为1.669,厚度约为7.5μm。TiO2/HA涂层的结合强度为14.04 MPa,但溶血率为6.02%较牺牲阳极法的4.64%有所下降。电化学性能测试表明TiO2/HA涂层降低了Ti6A14V合金的腐蚀倾向。在此基础上采用交流脉冲电合成法在Ti6A14V合金表面成功制备Ti02和HA弥散分布的复合涂层。对涂层的形貌和成分进行分析,并测试其血液相容性和在三种模拟体液中的电化学性能。HA复合涂层晶体分布呈平整和花簇状结构。平整部分由O、P、Ca和Ti元素组成,Ca/P比为1.671；花簇状部分由O、P和Ca元素组成,Ca/P比为1.668；涂层厚度约为7μm；结合强度为18.29MPa；涂层具有优异的血液相容性和电化学性能。采用扫描电化学方法(SECM)分析HA复合涂层的合成机理。更多还原

【Abstract】 Every year, the number of the patient repairing and replacing the teeth and bones in our country gradually increases due to the illness and traffic accidents. The development of implants materials has become the Chinese important components of the national economy. However, the poor biological activity, pitting corrosion and releasing metal ions harmful to human, which leads to the failure of implant, restrictes the Ti6A14V alloy in implants clinical application. Therefore, the Ti6A14V alloy surface modification has become the main implants materials development trend. In this paper, the corrosion behaviors in Hank’s solution, Ringer’s solution and Tyrode’s solution are tested, and HA coatings are prepared on Ti6A14V alloy by three kinds of electrochemical methods. Moreover, the biocompatibility and the electrochemical behaviors are researched.The results show that with the increase of temperature, the thermodynamics stabilities of Ti6A14V alloy decrease, the corrosion current densities increase, and the corrosion resistances reduce, gradually in the three kinds of simulated solution. The kinetic equation of pitting corrosion are iHank=1.0756·(t-1.1649)-1/2, iRinger= 1.0940·(t-1.4437)-1/2, iTyrode=2.0564(t-0.4568)-1/2. The pitting corrosion process is controlled by the dissolution of surface salt membrane. The activation energy Ea in Hank’s solution, Ringer’s solution and Tyrode’s solution are 45.71KJ/mol,155.1 KJ/mol and 87.62 KJ/mol respectively, which under the chemical reaction.Based on the cathodic electrodeposition, the HA coatings are prepared on Ti6A14V alloy by sacrificial anode method. The HA coating is composed of flower-like crystal or, the Ca/P ratio is 1.41, and the thickness is about 15μm. The bonding strength is 10.02MPa. By the platelet adhension test, dynamic clotting time curves and hemolysis rate, the HA coating has good blood compatibility. The electrochemical behaviors show the HA coating has more anti-corrosion characters than Ti6A14V alloy.In order to improve the bonding strength of the HA coating, TiO2 coating is prepared by microarc oxidation on Ti6A14V alloy. Then, the HA coating is synthesized using cathodic electrodeposition. The surface of TiO2 coating has circular microporous, and the thichness of coating is about 6μm. The TiO2/HA coating is composed of piece-like crystal with thichkness of 7.5μm. The bonding strength of TiO2/HA coating is 14.04MPa. But the blood compatibility is 6.02% worse than the 4.64% of the sacrificial node method. The electrochemical characters test impresses the TiO2/HA coating decreases the corrosion tend of Ti6A14V alloy.Based on the above, the single-layer of TiO2 and HA composite coating is prepared by ac pulse electric synthesis on Ti6A14V alloy. The morphology and composition of coating are tested. The blood compatibility and electrochemical behaviors in three kinds of simulated solution are tested, too. The HA composite coating is distributed of flat crystal and the flower-like crystal. The flat crystal is composed of O,P, Ca and Ti, whose Ca/P ratio is 1.671. The flower-like crystal is comosed of O, P and Ca, whose Ca/P ratio is 1.668. The thichness of HA composite coating is 7μm. The bonding strength of HA composite coating is 18.29MPa, and the HA composite coating has excellent blood compatibility and electrochemical performance. The synthesis mechanism is analysised by SECM.更多还原