循环伏安法测定氢在金属钛中的扩散系数

Determination of the Hydrogen Diffusion Coefficient in Titanium Alloy by Cyclic Voltammetry Method

采用循环伏安法于三电极测试系统中测定氢在金属钛片中的扩散系数,经实验结果表明,当TA 1钛金属薄片的循环伏安曲线中氧化峰峰位,随着电位扫描速度的增加而向正方向移动时,说明氢在钛中的扩散过程是完全不可逆反应过程。而氢的氧化峰峰值电流Ip与电压扫描速度的平方根1υ/2之间存在线性关系,氢原子的扩散过程是整个电极反应的控制步骤,测得氢扩散系数DH为3.31×1-0 8cm2/s,从而为进一步研究金属钛抗酸碱腐蚀机理及氢在金属钛中的扩散行为提供依据。

Determination of hydrogen diffusion coefficient of the titanium film was carried out in a three-electrode system by cyclic voltammetry method in this study. The experimental results indicated that the oxidation peak position in the cyclic voltammetry curve of TA1 titanium foil moved in the positive direction with increase of potential sweep rate. In the titanium alloy the oxidation peak current（Ip） demonstrates a good linear relationship with the square root of potential sweep rate （u^1/2）, and the hydrogen diffusion process is a fully reversible diffusion process. The diffusion of hydrogen atom is the entire electrode reaction controlling step. The diffusion coefficient Du is found to be 3.31 × 10^-8cm^2/s. It is to be a good proof of titanium and titanium alloy with outstanding corrosion resistance and accordingly provides the basis for further study on the corrosion mechanism in the titanium and the diffusion behavior of hydrogen in this metal.