医用镍钛合金表面涂层制备与性能研究

发布时间：2018-02-28 07:09

  本文关键词： 镍钛形状记忆合金 表面改性 高温氧化 聚合物涂层 附着力　出处：《西安理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：镍钛形状记忆合金(NiTi SMA)是一种具有形状记忆效应和超弹性的新型功能材料,同时因其具备良好的耐腐蚀性和生物相容性,在生物医用领域得以广泛应用。为了避免直接使用时可能出现的生物不相容性和细胞毒性,采用表面改性技术对镍钛形状记忆合金进行表面改性处理,在减少镍(Ni)离子析出的同时,使其具备比基体更优良的生物相容性、抗腐蚀性和耐磨性等特殊性能。本研究首先采用表面氧化的方法,在合金表面形成一层氧化层。通过对比化学氧化和高温氧化两种表面氧化方法的氧化效果,选择了表面氧化层氧含量较高的高温氧化处理工艺。最后,经硅烷偶联剂处理后,采用喷涂的方法在合金表面制备一层环氧树脂/聚四氟乙烯(EP/PTFE)聚合物涂层。复合环氧树脂和聚四氟乙烯,既保证了涂层的附着力,同时又改善了涂层表面的耐磨擦力等各方面力学性能。使用空气压缩机连接的高雾化气动喷漆枪进行喷涂,喷涂厚度可达到几微米,大大的降低了涂层的厚度。在本研究中,分析研究了表面的化学成分、形貌、粗糙度和氧化层厚度对镍钛形状记忆合金基材和涂层之间的附着力的影响。经硅烷偶联剂处理的镍钛形状记忆合金附着力明显高于未经处理的镍钛形状记忆合金。当加热温度的范围为300—700℃时,经600℃高温氧化处理过的样品的附着力最高。与此同时,在所有样品中,600℃恒温氧化30分钟的镍钛形状记忆合金具有最高的附着力。最后,研究分析得出,较高的附着力是由高的表面氧含量,均匀的表面形貌,合适的粗糙度和氧化层厚度决定的。
[Abstract]:Ni-Ti shape memory alloy (Niti SMA) is a new functional material with shape memory effect and superelasticity, and has good corrosion resistance and biocompatibility. In order to avoid the possible biocompatibility and cytotoxicity in direct use, the surface modification of Ni-Ti shape memory alloy was carried out by surface modification. In order to reduce the precipitation of Ni ~ (2 +) ions and make it have better biocompatibility, corrosion resistance and wear resistance than the matrix, this study firstly adopts the method of surface oxidation. A layer of oxidation layer was formed on the surface of the alloy. By comparing the oxidation effect of chemical oxidation and high temperature oxidation, a high temperature oxidation process with high oxygen content was selected. Finally, after silane coupling agent treatment, A coating of epoxy resin / polytetrafluoroethylene (EP / PTFEE) polymer coating was prepared on the alloy surface by spraying method. The adhesive force of the coating was ensured by composite epoxy resin and polytetrafluoroethylene (PTFE). At the same time, the friction resistance of the coating surface is improved. The spray thickness can reach several microns with the high atomization pneumatic spray gun connected by the air compressor, which greatly reduces the coating thickness. The chemical composition and morphology of the surface were analyzed and studied. Effect of roughness and oxide layer thickness on adhesion between substrate and coating of Ni-Ti shape memory alloy. Adhesion of Ni-Ti shape memory alloy treated by silane coupling agent is significantly higher than that of untreated Ni-Ti shape memory alloy. When the heating temperature ranges from 300 鈩，

本文编号：1546280