CP-Ti在含氟离子硝酸中电化学腐蚀行为

Electrochemical Corrosion Behavior of CP-Ti in Nitric Acid Containing Fluoride Ions

摘要:

采用开路电位(OCP)、动电位极化曲线(PPC)、电化学阻抗谱(EIS) 3种电化学测试手段对工业纯钛(CP-Ti)在含氟离子硝酸溶液中的电化学腐蚀行为进行研究。结果表明:随着硝酸溶液中氟离子浓度的增加,CP-Ti耐蚀性变差;影响CP-Ti耐蚀性转变的临界氟离子浓度为1. 25 mmol/L;氟离子与CP-Ti表面的氧化膜发生反应,致使均匀、致密的氧化膜溶解转变为多孔膜,降低了CP-Ti的耐蚀性。

Abstract:

The electrochemical corrosion behavior of CP-Ti in nitric acid solution containing fluoride ions was studied by electrochemical measurements including open circuit potential( OCP),potentiodynamic polarization curves( PPC)and electrochemical impedance spectroscopy( EIS). The results show that the corrosion resistance of CP-Ti decreases with the increase of fluoride ion concentration,and the critical value of fluoride ion concentration affecting the corrosion resistance of CP-Ti is 1. 25 mmol/L. The reaction between fluoride ion and protective oxide film on CP-Ti surface results in the dissolution of homogeneous and dense oxide film into porous film,which deteriorates the corrosion resistance of CP-Ti.