中文摘要：

采用双层辉光渗金属技术在Ti6Al4V钛合金表面制备钴基合金层以增强其耐磨、抗蚀性能,并考察了进行后喷丸复合以改善高温处理中对基材疲劳抗力损伤的处理对其性能的影响。利用扫描电子显微镜（SEM）、X射线衍射仪（XRD）、辉光放电光谱仪、显微硬度计、静态压入和动态压压疲劳设备分析和评价了钴基合金渗层的结构、成分分布、硬度和表面韧性,借助球-盘磨损试验机和电化学工作站研究了改性层对基材的干磨损行为和抗3.5%NaCl（质量分数）水溶液电化学腐蚀性能的影响。结果表明：在钛合金表面制备出由20μm沉积层和约5μm扩散层组成的钴基合金渗层,组成元素呈梯度渐变分布,表面硬度达HK_（0.98）N718,由于基材表面硬度提高了近一倍并具有良好的减摩润滑特性,使钛合金表面耐磨性提高了28倍,同时该渗层在3.5%NaCl（质量分数）水溶液中呈现良好的钝化特性,抗腐蚀性能优于钛合金基材。经陶瓷丸以0.15 mm A强度（Almen强度）喷丸后处理的钴基合金渗层的上表面沉积层减薄了1/5,表面硬度稍有增加,且表层硬度梯度呈现出一定程度的变缓,表面韧性却明显增强,但喷丸处理不仅使得钴基渗层表面耐磨性有所降低,其磨损率仅为钛合金的1/10,而且引起钴基合金渗层抗电化学腐蚀性能稍劣于钛合金基材。

英文摘要：

Cobalt-based alloy layer was prepared on Ti6A14V alloy substrate using double glow plasma alloying technology in order to improve the wear and corrosive resistance of substrate. Then the coated titanium afloy was treated by shot-peening to improve its thermal damage of fatigue resistance during high temperature processing. The microstructure, constituent distribution, hardness and toughness of the coating were studied by scanning electron microscopy（SEM） , X-ray diffraction（ XRD）, glow-discharge photo-electron spectros- copy, micro-hardness tester, static indentation tester and dynamic repeating press equipment, respectively. The influence of cobalt- based alloy coating as well as post-treatment on the wear behavior and corrosion resistance of Ti alloy substrate in ambient air and 3.5% NaC1 aqueous solution （mass fraction） was evaluated by ball-on-disk tribometer and electrochemical tests. The results indicated that the cobalt-based alloy layer consisted of deposition layer of 20 μm and diffusion layer of 5 μm. Composition elements were distrib- uted along the gradient layer. Surface hardness of alloyed layer was HK0.gsN 718. The wear resistance of Ti alloy substrate with Co- based alloying layer increased by 28 times, which was attributed to the improvement of substrate surface hardness nearly by 2 times by the coating and good lubrication and friction reduction properties of the coating. Furthermore, the coated surface showed obvious passi- vation features and had better corrosion resistance than that of Ti alloy substrate. After shot-peening post-treatment by ceramic balls at intensity of 0. 15 mm A （ Almen intensity）, the thickness of top deposition layer of Co-based alloy coating was thinned by 1/5, surface hardness increased slightly and hardness gradient in alloying layer became slow down to a certain degree, while surface toughness was enhanced obviously. But the shot-peening post-treatment not only led to reduction of surface wear resistance with the wear rate of com- bined treatment su