(1. 南昌航空大学 轻合金加工科学与技术国防重点学科实验室，南昌 330063；
2. 南昌航空大学 材料科学与工程学院，南昌 330063；
3. 中航工业北京青云航空仪表有限公司 表面处理分厂，北京 102402)
摘 要: 采用三维视频显微镜、粗糙度轮廓仪和电化学测试研究溴化锂溶液中不同温度条件下Ti-6Al-4V微观空蚀形貌、粗糙度以及电化学腐蚀行为，探讨温度对空蚀的影响机理。结果表明：温度的影响随空蚀时间增加不断加强，240 min时最为显著，之后影响减弱并趋于稳定。温度升高，空泡溃灭产生的微射流冲击强度增大，使表面钝化膜更易被破坏，同时腐蚀作用加速了点蚀形成，导致表面局部应力集中和更多电化学电池的产生，从而促进了力学和腐蚀因素，两者的协同作用加速了空蚀破坏。空蚀破坏程度在温度55 ℃时达到最大值，继续升高温度，腐蚀因素仍被促进，但微射流对表面的冲击强度减弱，对表面钝化膜的破坏作用降低，由于力学因素在空蚀中占据主导地位，因此使空蚀速率得到减缓。
关键字: Ti-6Al-4V合金；溴化锂溶液；温度；空蚀；影响机理
（1. National Defence Key Discipline Laboratory of Light Alloy Processing Science and Technology Institute, Nanchang Hangkong University, Nanchang 330063, China;
2. School of Material Science and Engineering, Nanchang Hangkong University, Nanchang 330063, China;
3. Department of Surface Treatment, Avic Beijing Keeven Aviation Instrument Co., Ltd., Beijing 102402, China）
Abstract:Three-dimensional video microscope, roughness profiler and electrochemical measurement were used to investigate the cavitation corrosion morphologies, surface roughness and electrochemical corrosion behavior of Ti-4Al-4V in LiBr solution at different temperatures. Furthermore, the influence mechanism of temperature on cavitation corrosion was discussed. The results show that the temperature effect is gradually strengthened as cavitation time increasing. It is most significant for 240 min, after that, it is reduced and tends to be stable. The rise in temperature enhances micro-jet impact strength, and the passive film on the surface is easy to be damaged. Simultaneously, the corrosion effect promotes the growth of more pits, which leads to the concentration of local stress and the formation of more electrochemical cell. As a result, the mechanical and electrochemical corrosion factors are promoted. The synergetic effect accelerates the cavitation corrosion. The damage of cavitation corrosion reaches a maximum value at 55 ℃. Afterwards, the continuous increase of temperature improves the corrosion effect. However, the attenuation of impact strength of micro-jets weakens the destruction of surface passivation film. The mechanical effect plays a dominant role in cavitation erosion, accordingly the cavitation corrosion rate is mitigated.
Key words: Ti-6Al-4V alloy; lithium bromide solution; temperature; cavitation corrosion; influence mechanism
