摘要
通过对钛合金TC4在3%NaCl和乙醇溶液中的极化曲线分析,认为钛合金在中性水溶液中的阴极析氢过程由H++1/2e=1/2H+2为反应控制步骤,阳极氧化过程控制步骤有非整比氧化物TiO1+X的参与.并指出在醇溶液中氧化反应主要为醇在钛合金表面被催化为醛的反应,醛进一步氧化为羧酸,导致钛合金的钝化膜活化,成为应力腐蚀的诱因.对在自腐蚀电位以上500毫伏下电解液的红外光谱分析支持了这一设想,分析表明溶液中确实存在羧酸和醛,同时在电解过程中发现钛合金电极附近的溶液pH值明显降低.
The cathode and anode Tafel slopes of titanium alloy TC4 in 3%NaCl solution and ethanol were much greater than 0 118 V.It was difficult to explain the phenome na by traditional electrochemical mechanisms.We thought that the cathode process was controlled by the process H^++1/2 e = 1/2H^+ 2 was the very point to exp lain the cathode Tafel slope was about 0 23 V.And in anode process the nonstoic hiomet ric oxide TiO 1+X (0 5<X<1) took part in the electrochemical reactions as intermidiate production.It made the anode Tafel slope much greater than 0 118 V.And the anode process of TC4 in ethanol was quite different with that in 3%Na Cl solution.After analyzing the electrolyte after polarization measurements of T C4 in the ethanol,we found that there was acetic acid in the electrolyte,which must be ox ide of ethanol.Maybe the acetic acid was the reason of stress corrosion suscepti bility of titanium alloy in ethanol.
出处
《腐蚀科学与防护技术》
CAS
CSCD
北大核心
2005年第3期154-158,共5页
Corrosion Science and Protection Technology
