复合型扫描微pH电极及其在局部腐蚀中的应用

Fabrication of Composite Scanning Micro pH Electrode and Its Application in Localized Corrosion

研制了一种新型的微米级复合型扫描叫探针.该探针具有体积小、响应速度快、稳定性好和制作方便等优点,能很好地满足微区 PH快速测定的要求 应用复合型扫描微pH电极技术研究了Al/Cu合金在0.01mol·L-1NaCl溶液中开路状态下局部腐蚀发生的早期过程.

A novel composite scanning micro pH electrode was fabricated. The IrOx-pH electrode produced in a carbonate melt exhibited high stability, a fast potential response and ideal Nernstian response. The slope of the electrode at 15℃ was 56. 8 mV/pH, which was very close to the theoretical value. The 90% potential response time for a pH change from 1. 75 to 13. 90 was less than 0. 5 s. The composite scanning micro pH electrode is a promising apparatus for detecting the pH distribution on metal/solution interface. pH image on the surface of Al/Cu galvanic couple showed that both the anodic and cathodic areas could be sensed well. Localized corrosion took place on the interface of Al/Cu couple. The localized corrosion developed with time and pH value around the pitting decreased gradually.