镁合金表面硅烷处理及复合涂层的制备及性能研究

发布时间：2018-05-02 07:38

本文选题：镁合金 + 硅烷偶联剂　；参考：《吉林大学》2017年硕士论文

【摘要】：镁合金具有良好的力学性能,镁合金已经广泛的应用于汽车,电子等领域。同时其还生物相容性和可降解性,机械性能与人体骨骼相近,可以有效地避免“应力屏蔽”效应,二次手术,是一种很有潜力的生物医用材料。但是由于镁合金的性质极其活泼,极容易发生腐蚀,无法满足作为植物材料服役期限的要求,因此需要研究如何控制其降解速率并且进一步提升其生物相容性。本实验利用AZ60镁合金作为基体,利用KH550型硅烷偶联剂对镁合金进行硅烷处理,同时利用处理的硅烷涂层诱导生长制备复合涂层。首先,利用硅烷偶联剂水解,对镁合金进行硅烷处理在表面形成一层硅烷涂层,实验主要通过研究KH550含量、醇水比、p H、水解时间和涂覆层数进行探究并找出最佳工艺参数。并对最佳工艺条件下,通过FTIR、SEM、电化学工作站及浸泡实验对涂层成分和性能进行表征。然后,利用仿生诱导的方式在硅烷涂层表面诱导生长DCDP涂层和碳酸钙涂层。然后利用XRD、FTIR、SEM,电化学工作站和浸泡实验对涂层的成分和性能进行表征和分析。实验结果表明,利用KH550型硅烷偶联剂对AZ60镁合金进行硅烷处理,可以有效的提高AZ60镁合金基体的耐腐蚀性能。最佳工艺参数为KH550的含量为6%,醇水比为1:9、溶液p H为11,水解6小时后,涂覆2层。在这个条件下,涂层表面较为均匀平整,涂层的腐蚀电位提高了0.337V,腐蚀电流密度下降为基体的1/14。浸泡实验表明硅烷涂层可以降低基体的析氢速率,稳定周围环境的p H,有效的降低了基体的腐蚀速率,并且硅烷涂层也具备一定的生物矿化能力。通过硅烷偶联剂诱导生长出的碳酸钙涂层可以提高基体的耐蚀性,而DCDP涂层可以进一步提高基体的耐蚀性。碳酸钙的涂层表面形貌为均匀致密的块状,涂层的腐蚀电位为-1.3584V,腐蚀电流密度为13.202μA,浸泡实验后的膜层会出现一定程度的脱落和开裂;而DCDP涂层则是在表面呈现出纤维状,有利于细胞在表面的附着,同时具备良好的电化学性能,腐蚀电位为-1.0673V,腐蚀电流密度为0.4729μA,耐蚀性能有显著的提升。同时,浸泡后的涂层上会形成絮状的腐蚀产物,主要成分为Ca、P,说明涂层具备良好的生物相容性和生物矿化能力。
[Abstract]:Magnesium alloys have good mechanical properties, magnesium alloys have been widely used in automotive, electronic and other fields. At the same time, it has biocompatibility and biodegradability, and its mechanical property is similar to that of human skeleton, which can effectively avoid the "stress shielding" effect. Secondary surgery is a potential biomedical material. However, magnesium alloys are very active and easy to corrode, which can not meet the requirements of the service life of plant materials. Therefore, it is necessary to study how to control the degradation rate of magnesium alloys and further improve their biocompatibility. In this experiment, AZ60 magnesium alloy was used as substrate, KH550 silane coupling agent was used for silane treatment of magnesium alloy, and composite coating was prepared by induced growth of treated silane coating. Firstly, silane coating was formed on magnesium alloy surface by silane treatment with silane coupling agent. The content of KH550, the ratio of alcohol to water, hydrolysis time and coating number were studied and the optimum process parameters were found out. The composition and properties of the coating were characterized by FTIR SEM, electrochemical workstation and immersion test. Then, DCDP coating and calcium carbonate coating were induced on the surface of silane coating by bionic induction. Then the composition and properties of the coating were characterized and analyzed by XRDX FTIR SEM, electrochemical workstation and immersion test. The results show that KH550 silane coupling agent can effectively improve the corrosion resistance of AZ60 magnesium alloy matrix by silane treatment. The optimum technological parameters were as follows: the content of KH550 was 6%, the ratio of alcohol to water was 1: 9, solution pH was 11. After 6 hours of hydrolysis, two layers were coated. Under this condition, the surface of the coating is even and flat, the corrosion potential of the coating increases by 0.337V, and the corrosion current density decreases to 1 / 14 of the substrate. Soaking experiments show that silane coating can reduce the hydrogen evolution rate of the substrate, stabilize the ambient pH, effectively reduce the corrosion rate of the substrate, and the silane coating also has certain biomineralization ability. Caco _ 3 coating induced by silane coupling agent can improve the corrosion resistance of the substrate, while the DCDP coating can further improve the corrosion resistance of the substrate. The surface morphology of calcium carbonate coating is uniform and dense, the corrosion potential of the coating is -1.3584 V, the corrosion current density is 13.202 渭 A. the film layer after soaking will be shedding and cracking to a certain extent, while the DCDP coating is fibrous on the surface, and the corrosion current density of the coating is 13.202 渭 A, and the corrosion potential of the coating is -1.3584 V, and the corrosion current density is 13.202 渭 A. The corrosion potential is -1.0673V and the corrosion current density is 0.4729 渭 A. At the same time, a flocculent corrosion product was formed on the coating after soaking, which showed that the coating had good biocompatibility and biomineralization ability.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG174.4

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