【摘要】 为了有效解决钛合金-铝合金之间的接触腐蚀问题,采用无铬达克罗技术在TC4钛合金表面制备了Zn-Al合金涂层,并检测了涂层的组织和厚度,对有涂层的TC4合金试样进行了盐雾试验,以研究涂层的防蚀性能。结果表明,TC4合金的Zn-Al涂层均匀致密,厚约35μm,与基体结合良好。在盐雾试验29 d后,无涂层钛合金-铝合金接触偶对的腐蚀程度要比有涂层的钛合金-铝合金接触偶对严重得多。电化学测试结果表明,涂层钛合金-铝合金接触偶的自腐蚀电位差比无涂层钛合金-铝合金接触偶的自腐蚀电位差低315 mV左右,前者的开路电位差则比后者低244 mV,并且接触偶对的阴、阳两极发生了转换,即原先作阳极的铝合金变成了被保护的阴极。Zn-Al合金涂层的存在能有效降低相互接触的钛-铝合金之间的电位差,具有一定的防腐蚀作用。更多还原

【Abstract】 In order to effectively remove the problem of corrosion of titanium alloy and aluminum alloy in contact with each other, Zn-Al alloy coating was prepared on the TC4 titanium alloy by a chromium-free Dacrometal technology, and the Zn-Al coating was subjected to microstructure survey, thickness measurements, and to salt spray test for the purpose of examining its corrosion resistance. The results showed that the Zn-Al coating was uniform and compact, as thick as about 35 μm, and well bonded to the base metal. After being subjected to salt spray test for 20 days, the coating-free TC4 alloy-aluminum alloy couple was corroded much more seriously than the Zn-Al alloy-coated TC4 alloy-aluminum alloy couple. From electrochemical test results it was seen that selfcorrosion potential difference of the Zn-Al alloy-coated TC4 alloy-aluminum alloy couple was about 315 mV less than that of the coating-free TC4 alloy-aluminum alloy couple, whereas open-circuit potential difference of the former was 244 mV less than that of the latter, and that cathode and anode of the contact couple were reversed, that is, the original aluminum alloy as the anode became cathode which was protected from corrosion. The Zn-Al alloy coating on TC4 alloy made it possible to reduce evidently potential difference between titanium alloy and aluminum alloy in contact with each other, thus protecting the alloys from corrosion in a certain degree.更多还原