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医用钛合金表面改性层腐蚀及腐蚀-磨损性能研究摘 要钛及钛合金因具有质轻、耐腐蚀性能优异、生物相容性好、较低的弹性模量等优异特性，被认为是理想的生物医用金属材料，但其摩擦学性能低劣。
在电解质环境中，表面被机械划伤后，可导致表面钝化层的破坏，出现磨损-腐蚀加速。
针对目前被广泛使用的医用植入钛合金Ti6Al4V（TC4）在模拟人工体液(Hank’s溶液)、模拟人工唾液及蒸馏水中可能出现的腐蚀-磨损问题，鉴于性能优良的钛-钼系的β型钛合金是医用钛合金的发展趋势考虑，我们拟以等离子表面合金化技术在钛合金（TC4）表面制备含钼合金化改性层，并对其组织结构、腐蚀及腐蚀-磨损性能分别进行研究。
采用GDS 、SEM、XRD等手段对改性层的成分与组织结构分别进行检测。
对改性层的制备工艺及组织结构进行试验对比，得到利用等离子表面合金化技术制备一定厚度致密的合金化层的最佳工艺。
利用电化学分析方法，对比研究未经表面改性处理的基材和经过渗钼、钼氮共渗和渗氮表面改性处理的试样在Hank’s溶液、模拟人工唾液及蒸馏水中的电化学腐蚀行为。
结果表明：表面改性处理对钛合金（TC4）的耐蚀性有不同程度的影响。
其中钛合金经钼氮共渗表面改性处理后，在三种不同介质中的耐蚀性能均得到改善。
借助腐蚀-磨损试验，考察了未经表面改性处理的基材和经过钼氮共渗表面改性处理的试样在大气、Hank’s溶液、模拟人工唾液及蒸馏水中的腐蚀-磨损行为。
结果显示：钛合金（TC4）经过钼氮共渗表面处理后，耐磨性可以提高近十倍。
表明钼氮表面改性层可以有效保护较软的基体，使钛合金（TC4）的摩擦学性能得到很大改善。
以上系统研究结果表明：钼氮共渗处理可以有效提高钛合金（TC4）的耐蚀性和腐蚀-磨损性能。
因此等离子表面冶金技术在生物医用钛合金表面改性方面是一种比较有效的方法。
关键词：钛合金，等离子表面合金化技术，改性层，电化学腐蚀，腐蚀-磨损CORRSION AND CORROSION-WEAR BEHA VIOR OF MODIFIED LAYERS ON BIOMEDICAL TITANIUM ALLOYABSTRACTTitanium and its alloys are desirable metal biomaterial, due to their lower density, excellent corrosion resistance, better biocompatibility and low elastic modulus .However, the deficiencies of titanium alloy are obvious as well, such as inferior tribological property, low hardness. When its surface passivation film is destroyed by mechanical damage, which will cause aggravation of corrosive-wear in some electrolyte environment.Focusing on the corrosive-wear issues of implantation titanium alloys (Ti6Al4V) in artificial body solution, artificial saliva and water, and considering of excellent property Ti-Mo β titanium alloys, in this paper, Mo, Mo-N modified and nitrided layers were fabricated on Ti6Al4V alloy base by plasma surface alloying technique. The component, microstructure, electrochemical corrosion properties and corrosive-wear behaviors of these surface modified Ti6Al4V alloy were investigated.The microstructure and composition of the surface modified layer were investigated by SEM, X - ray diffraction (XRD) and glow discharge optical emission spectroscopy (GDOES). The modified layer preparation process andits microstructure were compared. Results show the certain thickness and compact alloy layer can be obtained by plasma surface alloying technology.Applying electrochemical analysis method, the electrochemical corrosive behavior of base material Ti6Al4V and modified Ti6Al4V in artificial body solution, artificial saliva and distilled water have been tested and compared respectively. Results show that surface modification treatment affect corrosion resistance of TC4 differently, and Mo-N modified layer perform very good corrosion resistance in above three different media.The corrosive-wear behavior of base material Ti6Al4V and Mo-N modified Ti6Al4V have been tested and compared in air, artificial body solution, artificial saliva and distilled water. Results show that Mo-N modified layer can improve wear resistance of Ti6Al4V about ten times, and perform excellent corrosive-wear resistance in above four different media. Further investigation manifest Mo-N modified layer can effectively protect pliabler Ti6Al4V substrate and has much better friction-reducing and anti-wear ability.It is indicated that Mo-N modified layer have excellent property of corrosion resistance and wear resistance, and can remarkablly improve tribological property of Ti6Al4V .KEY WORDS: Titanium alloy, Plasma surface alloying technology, surface modified layer, electrochemical corrosion, corrosion-wear第一章文献综述1.1 钛及钛合金1.1.1 概述钛在地壳里的分布范围比较广泛，世界储量约34亿吨，在所有元素中含量居第九位[1]。
