【作者】 丁明惠；

【导师】 郑玉峰；

【作者基本信息】 哈尔滨工程大学 ， 材料学， 2010， 博士

【摘要】 采用射频磁控溅射技术在316L不锈钢表面制备了Ta_xC_1-x、TaC_xN_1-x和Ta（Ti）N三种惰性涂层。采用X射线衍射分析、透射电子显微观察、扫描电子显微镜观察、原子力显微镜观察、X射线光电子谱分析、纳米硬度、划痕实验、摩擦实验、电化学实验、血小板粘附实验研究了这三种惰性涂层的微观结构、相组成、力学性能、抗腐蚀性以及血液相容性,重点考察了磁控溅射工艺参数对其性能的影响规律。SEM扫描结果显示三种惰性涂层都具有致密的结构,涂层中无大的孔洞存在。XRD结果表明溅射工艺参数对三种惰性涂层的微观结构都有影响。靶材上C与Ta的面积比和基体温度对Ta_xC_1-x涂层的相结构有明显的影响。靶材上C与Ta的面积比为1:3.8时,Ta_xC_1-x涂层的相组成为C3Ta4和Ta2C。C与Ta的面积比为1:5时,沉积温度低于150℃时Ta_xC_1-x涂层为非晶态结构,基体温度为300℃时Ta_xC_1-x涂层由15 25纳米的TaC纳米球晶组成。氮氩流量比和基体温度的不同都会导致TaC_xN_1-x涂层微观结构的变化,氮氩流量比为2:18时,基体温度低于200℃时TaC_xN_1-x涂层为非晶态结构,基体温度为200℃时TaC_xN_1-x涂层由6 9纳米的Ta2CN纳米晶组成。无Ti掺杂的Ta（Ti）N涂层为面心立方结构的晶体。随着涂层中Ti原子浓度的增加,Ta（Ti）N涂层的衍射图中没有出现TiN的衍射峰。发生变化的是TaN衍射峰向高角度方向偏移,这说明一部分Ti原子取代了Ta原子形成了TaN（Ti）固溶体。由于TaN和TiN都具有面心立方结构这种固溶体很容易形成。纳米压痕的测试结果表明较高的温度下制备的Ta_xC_1-x和TaC_xN_1-x涂层有更高的硬度。氮氩流量比对TaC_xN_1-x涂层的硬度也会产生影响,当氮氩流量比为2:18时,TaC_xN_1-x涂层的硬度高达32 GPa。Ti原子取代Ta原子形成了Ta（Ti）N固溶体,固溶强化效应使Ta（Ti）N涂层的硬度高于TaN涂层的硬度。摩擦实验结果显示,Ta_xC_1-x和TaC_xN_1-x涂层都有低的摩擦系数,耐磨性好于316L不锈钢基体。划痕实验结果表明基体温度的提高有利于Ta_xC_1-x和TaC_xN_1-x涂层与基体结合力的提高。电化学测试结果表明,在PBS模拟体液中Ta_xC_1-x、TaC_xN_1-x和Ta（Ti）N三种惰性涂层比316L不锈钢基体有更好的耐腐蚀性能。血液相容性实验结果表明,三种惰性涂层的血液相容性均优于316L不锈钢基体的血液相容性。Ta_xC_1-x和TaC_xN_1-x涂层的血液相容性主要受其表面粗糙度的影响。Ta（Ti）N涂层中Ti原子浓度的不同对其血液相容性没有明显的影响。更多还原

【Abstract】 Three series of inert coatings of Ta_xC_1-x, TaC_xN_1-x and Ta（Ti）N coatings were deposited on the surface of 316L stainless steel （SS） by RF magnetron sputtering in order to improve its corrosion resistance and hemocompatibility. The microsturcture, phase constitution, mechanical properties, corrosion resistance, and hemocompatilbity of the three series of Ta_xC_1-x, TaC_xN_1-x and Ta（Ti）N coatings were systematically investigated. The influence of RF magnetron sputtering process parameters on these properties was revealed by X-ray diffraction （XRD）, transmission electron micrography （TEM）, scan electron micrography （SEM）, atomic force microscopy （AFM）, X-ray photoelectron spectroscopy （XPS）, scratch test, nanoindentation techniques, wear test, electrochemical measurments and biocompatibility evaluations.The SEM results show that all the inert coatings exhibite dense structures without cavities. XRD results reveal that the microstructures of these coatings are very sensitive to the sputtering process parameters. The area ratio of C:Ta and substrate temperature （Ts） have a great effect on the microstructure of Ta_xC_1-x coatings. The Ta_xC_1-x coatings are composed of C3Ta4 phase and Ta2C phase when the area ratio of C:Ta is 1:3.8. Ts can also significantly change the microstructure of Ta_xC_1-x coatings. When Ts is lower than 150℃, the Ta_xC_1-x coatings are in amorphous condition, whereas when Ts is higher than 150℃, TaC phase is formed, exhibiting in the form of particulates with the crystallite sizes of about 15 25 nm （Ts=300℃）. Ts and nitrogen to argon gas ratios （N2/Ar） can significantly change the microstructures of TaC_xN_1-x coatings. When Ts is lower than 200℃（N2/Ar = 2:18）, the TaC_xN_1-x coatings are in amorphous condition; whereas, when Ts is increased to 200℃（N2/Ar = 2:18）, Ta2CN phase is formed, exhibiting in the form of fine particulates with the crystallite sizes of about 6 9 nm. The Ta（Ti）N coating without Ti presents an fcc lattice structure. No diffraction peaks of TiN are indentified for Ta（Ti）N coatings with all Ti contents. However, the shift of all TaN peaks towards higher angles can be observed. The structure evolution results reveal that the small amounts of Ti in the coatings substitute a part of Ta atomic and the solid solution Ta（Ti）N is formed, which can be easily understood by the same lattice structure （fcc） between TaN and TiN.The nanoindentation results indicate that the Ta_xC_1-x coating and TaC_xN_1-x coating grown at high temperauture have a high hardness and modulus. At the same time, nitrogen to argon gas ratios can also change the nanohardness of TaC_xN_1-x coating. The hardness of up to 32 GPa is achieved at N₂/Ar of 2:18. The Ta（Ti）N coating has higher hardness than TaN coating for the forming of the solid solution Ta（Ti）N. The tribology results demonstrate that Ta_xC_1-x and TaC_xN_1-x coatings exhibite excellent wear resistance. The scratch results demonstrate that Ta_xC_1-x and TaC_xN_1-x coatings deposited at high Ts exhibite good adhesion performance.The results of potentiodynamic polarization show that the corrosion resistance of the 316L SS can be improved significantly because of the deposited Ta_xC_1-x, TaC_xN_1-x and Ta（Ti）N coatings. The platelet adhesion test results indicate that the hemocompatibility of the Ta_xC_1-x and TaC_xN_1-x coating are influenced by the surface roughness. The Ti atomic concentrations in the Ta（Ti）N coatings have no significant effect on the hemocompatibility.更多还原