中文摘要：

用硅电极分别在空气和硅油中对钛合金表面进行了电火花沉积强化改性。利用扫描电子显微镜、X射线衍射仪、辉光放电光谱仪分析了改性层的形态、结构和成分分布,采用显微硬度计测试了改性层的硬度分布,通过电化学极化曲线和交流阻抗技术测试评价了改性层的耐蚀性,利用球-盘磨损试验机研究了改性层的耐空气环境磨损与耐NaCl水溶液腐蚀磨损性能。研究结果表明：硅电极在空气中电火花强化Ti6Al4V合金表面,形成约40μm厚合金化改性层,主要物相为Ti5Si3、TiSi2、Si和TiN,硬度达2180HK。硅电极在硅油介质中电火花强化Ti6Al4V合金表面,形成约40μm厚的合金化改性层,主要物相为Ti5Si3、TiSi2和TiC,硬度达1810HK。硅电极电火花强化改性层的组成和硬度沿层深均呈梯度变化。硅电极电火花强化改性层显著提高了钛合金基材的抗空气环境干磨损性能,显著提高了钛合金基材的耐NaCl水溶液腐蚀磨损性能。

英文摘要：

Titanium alloy surfaces were modified with silicon electrode in ambient air and silicon oil by electro-spark surface strengthening process.The morphology,microstructure,and composition distribution of the modified layers were analyzed by scanning electron microscope,X-ray diffraction,and glow discharge photoelectron spectroscopy.The hardness of the modified layers was studied by micro-hardness tester.The corrosion resistance of the modified layers was evaluated by electrochemical polarization and impedance spectroscopy technique.The wear resistance in ambient air and the corrosive wear resistance in NaCl solution of the modified layers were studied by ball-on-disk wear tester.The results show that about 40 μm electro-spark strengthened layer is obtained with silicon electrode in ambient air.The main phase of the modified layer is Ti5Si3,TiSi2,Si and TiN.The hardness of the modified layer is 2180HK.About 40 μm electro-spark strengthened layer is obtained with silicon electrode in silicon oil.The main phase of the modified layer is Ti5Si3,TiSi2 and TiC.The hardness of the modified layer is 1810HK.The composition and micro-hardness of the modified layers show gradient distributions along the depth.Electro-spark strengthened layers with silicon electrode significantly improve wear resistance of titanium alloy substrate in ambient air and the corrosive wear resistance of titanium alloy substrate in NaCl solution.